Epidemiology of Weaning Outcome according to a New Definition. The WIND Study

The effects of hypnosis and music intervention on comfort and anxiety during weaning from mechanical ventilation: A pilot study

OBJECTIVE

To compare the efficacy of hypnosis or music intervention in alleviating distressing symptoms in critically ill patients facing extended or challenging liberation from mechanical ventilation (MV).

STUDY DESIGN

Single-center, prospective interventional trial.

METHODS

Critically ill patients experiencing extended or challenging MV weaning were assigned to either a hypnosis group or a music intervention group where participants chose calming music from a provided list for a 30-min session. Inclusion criteria encompassed periods during pressure support ventilation, spontaneous breathing trials with tracheostomy or immediately after MV weaning. Hemodynamic, respiratory and electroencephalogram (EEG) parameters were collected before, during and after the intervention. Cortisol blood levels were also assessed. The primary outcome was the patient comfort and anxiety levels assessed using a Visual Analog Scale (VAS).

RESULTS

Twenty-nine patients out of 75 eligible patients were enrolled in the study (15 in the hypnosis group and 14 in the music intervention group). The comfort level increased from 4 [2-6] to 8 [7-9] (p < 0.01) and from 5 [4-6] to 7 [5-8] (p < 0.01) for the hypnosis and music intervention groups, respectively (both p < 0.01). The anxiety level decreased from 5 [5-7] to 3 [2-5] (p < 0.01) and from 6 [5-8] to 4 [3-6] (p < 0.01) for the hypnosis and music intervention groups, respectively (both p < 0.01). No differences were observed between the study groups. Respiratory rate decreased after hypnosis from 28 [25-37] to 24 [23-35] (p < 0.01), but was unchanged with music intervention. Heart rate showed a significant decline from baseline values after both interventions, but reverted to initial values subsequently. Mean arterial pressure exhibited an elevation from 94 (86-110) to 99 (80-108) mmHg after hypnosis (p = 0.01), while a reduction from 87 (75-101) to 82 (74-88) mmHg after music intervention (p = 0.01). Cortisol concentrations significantly decreased from 249 [175-291] to 207 [145-242] μg/L after music intervention (p = 0.02), but was unchanged after hypnosis (both p = 0.04). Both interventions led to a significant decrease in slow delta power and an increase in theta and alpha power on EEG, indicative of a hypnosis-like state.

CONCLUSIONS

In this pilot study, a single session of either hypnosis or music intervention was demonstrated to effectively reduce anxiety and enhance comfort, in critically ill patients facing extended or challenging MV weaning.

Early versus Delayed Switching from Controlled to Assisted Ventilation: A Target Trial Emulation

Rationale: In critically ill patients receiving invasive mechanical ventilation, switching from controlled to assisted ventilation is a crucial milestone toward ventilator liberation. The optimal timing for switching to assisted ventilation has not been studied. Objectives: Our objective was to determine whether a strategy of early compared with delayed switching affects the duration of invasive mechanical ventilation, ICU length of stay, and mortality. Methods: We conducted a target trial emulation using the prospective, global WEAN SAFE (the WorldwidE AssessmeNt of Separation of pAtients From ventilatory assistancE) dataset. Patients were eligible for switching if they were still on controlled mechanical ventilation, were not receiving neuromuscular blockers, and had PaO2:FiO2 ratios >150 mm Hg. We compared an "early switching" strategy (switch within 1 day after reaching switching eligibility criteria) with a "delayed switching" strategy (switch 1 or more days after reaching the switching eligibility criteria). The primary outcome was the 28-day cumulative incidence of successful extubation. Secondary outcomes included 28-day and 90-day ICU discharge and ICU mortality. Measurements and Main Results: A total of 1,489 patients met the switching eligibility criteria. The early-switch group had, on average, 4 additional days of being successfully extubated over the 28-day period (95% confidence interval [CI], 3-6 days; P < 0.001) compared with the delayed group, with a higher difference in cumulative incidence of successful extubation at Day 28 (7% [95% CI, 0-13%]; P = 0.04). Early switching was associated with an 11% higher cumulative incidence of ICU discharge at Day 28 (95% CI, 7-18%; P < 0.001) and an average of 7 additional days discharged from the ICU over the 90-day period (95% CI, 4-12 days; P < 0.001) compared with delayed switching. ICU mortality rates did not differ between the strategies. Conclusions: Early switching from controlled to assisted ventilation is associated with shorter duration of invasive mechanical ventilation and ICU stay compared with delayed switching.

A nurse-driven protocol for early weaning from mechanical ventilation in patients with acute respiratory failure: A pilot study

OBJECTIVES

To assess the compliance and acceptance of a nurse-driven early weaning protocol from the initiation of spontaneous ventilation (SV) to extubation in patients with acute respiratory failure (ARF) in the intensive care unit (ICU).

METHODS

This monocentric, prospective pilot study included patients admitted to the ICU with ARF and requiring invasive mechanical ventilation (IMV) for more than 48 h, between February 2021 and April 2024. The weaning protocol (WP) was initiated after a successful 30-minute SV trial with pressure support (PS). Every 3 h, nurses reduced PS by 2 cmH2O, fraction of inspired oxygen (FiO2) by 5%, and positive end-expiratory pressure (PEEP) according to a predefined protocol. When minimum PS and PEEP levels were reached, the patient was extubated after a successful T-tube test. The primary outcome was compliance with the WP assessed by the percentage of time spent in agreement with WP. The secondary outcome was nurse acceptance, assessed by an anonymous survey on a visual analogue scale from 0 to 10.

RESULTS

Of the 50 patients enrolled, 30 (60 %) had COVID-19 pneumonia. The median duration of IMV was 21 days per patient [IQR: 10-34], with a median WP duration of 11 days [IQR: 4-21.5]. Protocol compliance was 76 %. Thirty-two of 37 nurses (86 %) completed the survey and rated the acceptance of the WP as 8/10 [IQR: 7.75-9]. Workload was identified as a barrier to compliance with a median score of 5/10 [IQR: 2-7]. We reported 9/50 (18 %) extubation failures.

CONCLUSIONS

This nurse-driven protocol for early weaning of patients with ARF had good compliance and acceptance by the nurse team despite the COVID-19 pandemic health crisis.

IMPLICATIONS FOR CLINICAL PRACTICE

It is essential to incorporate nursing feedback if we are to improve the protocols for ventilatory weaning patients in ICU.

Improving weaning and liberation from mechanical ventilation for tracheostomy patients: a quality improvement initiative

For patients in the intensive care unit (ICU), prolonged mechanical ventilation is associated with poor outcomes. A quality improvement (QI) initiative with the aim of reducing median time on the ventilator for tracheostomy patients was undertaken at a tertiary care ICU in Toronto, Canada. A QI team was formed, and using QI methodology, a deep understanding of our local process was achieved. Based on this information and on the latest evidence on weaning, a standard tracheostomy weaning protocol was designed. The protocol was refined through three developmental and two testing plan-do-study-act cycles. This study was a prospective time series showing the effect of the implementation of our intervention on tracheotomy patients' time on the ventilator. The baseline median number of days on the ventilator after tracheostomy insertion was 17. Within 12 months of the introduction of the intervention, a shift in the data showing a reduction in the median time on the ventilator to 10.6 days had developed. Length of stay in the ICU was reduced by 4.3 days. Adherence and compliance to the protocol also improved over time. A standard tracheostomy weaning protocol was successfully developed, tested and implemented in a tertiary care ICU. Using strategies such as frequent communication with key stakeholders and incorporating a tracheostomy weaning progress sheet to document and track tracheostomy patients and their outcomes, this QI intervention has become engrained in the local culture at our centre. This weaning protocol has successfully reduced the median time on the ventilator for tracheostomy patients by over 6 days.

ARDS Weaning: The Impact of Abnormal Breathing Patterns Detected by Electric Tomography Impedance and Respiratory Mechanics Monitoring

Background: After the improvement of the initial phase of ARDS, when the patients begin spontaneous breathing and weaning from mechanical ventilation, some patients may present abnormal breathing patterns, whose evaluation of the repercussions were poorly studied. This study proposed to evaluate abnormal breathing patterns through the use of electrical impedance tomography (EIT), and clinical, respiratory mechanics, and ventilatory parameters according to the types of weaning from mechanical ventilation. Methods: This was a prospective cohort study of subjects with ARDS who were considered able to be weaned from mechanical ventilation in the clinical-surgical ICU. Weaning types were defined as simple, difficult, and prolonged weaning. EIT, ventilatory, lung mechanics, and clinical data were collected. Data were collected at baseline in a controlled ventilatory mode and, after neuromuscular blocker withdrawal, data were collected after 30 min, 2 h, and 24 h. EIT parameter analysis was performed for ventilation distribution in the lung regions, pendelluft, breath-stacking, reverse-trigger, double-trigger, and asynchrony index. Results: The study included 25 subjects who were divided into 3 groups (9/25 simple, 8/25 difficult, and 8/25 prolonged weaning). The prolonged weaning group showed more delirium, ICU-acquired weakness, stay in ICU, and hospital and ICU mortality. During the change from controlled to spontaneous mode, we observed increased tidal volumes and driving pressures, which were mainly found in the prolonged weaning group when compared with the simple weaning group. The prolonged weaning group showed a higher flow index, more asynchronies during volume-assisted ventilation, a higher incidence of pendelluft, and redistribution of ventilation to posterior regions visualized by EIT. Conclusions: The present study showed abnormal breathing patterns in the prolonged weaning group. The clinical occult findings of abnormal breathing patterns could be monitored, mainly through EIT and with better assessment of pulmonary mechanics.

Inspiratory effort and respiratory muscle activation during different breathing conditions in patients with weaning difficulties: An exploratory study

BACKGROUND

Recent studies suggest that fast and deep inspirations against either low or high external loads may provide patients with weaning difficulties with a training stimulus during inspiratory muscle training (IMT). However, the relationship between external IMT load, reflected by changes in airway pressure swings (ΔPaw), and total inspiratory effort, measured by oesophageal pressure swings (ΔPes), remains unexplored. Additionally, the association between ΔPes, ΔPaw, and inspiratory muscle activations remains unclear.

OBJECTIVES

The ai of this study was to compare ΔPes and ΔPaw and their relationship with inspiratory muscle activation in patients with weaning difficulties during different breathing conditions.

METHODS

ΔPes and scalene, sternocleidomastoid, and parasternal intercostal muscles activation were recorded during the following conditions: 1) (proportional) pressure support ventilation; 2) unsupported spontaneous breathing; 3) low-load IMT (load: <10% maximal inspiratory pressure, PImax = 3 cmH2O) executed with slow and deep inspirations (low-load slow) and 4) low-load IMT (load: <10% maximal inspiratory pressure, PImax = 3 cmH2O) executed with fast deep inspirations (low-load fast); and 5) high-load IMT (load ∼ 30% PImax) executed with fast and deep inspirations. ΔPaw, end-inspiratory lung volume, and peak inspiratory flow were recorded during conditions 2-5. Variables were compared across conditions using mixed-model analysis. Spearman's rank correlations were calculated between inspiratory muscle activations and both ΔPes and ΔPaw.

RESULTS

Five patients (age: 68 ± 1 y; 20% male; PImax: 37 ± 7 cmH2O [59 ± 23% predicted]; forced vital capacity: 0.66 ± 0.16 L [21 ± 6% predicted]) were included in the study. ΔPes values were 3-4 times larger than ΔPaw values during unsupported spontaneous breathing and IMT conditions. ΔPes, sternocleidomastoid activation, end-inspiratory lung volume, and peak inspiratory flow were larger during low-load fast IMT than during low-load slow IMT and unsupported spontaneous breathing but were similar between low-load fast and high-load IMTs. Inspiratory muscle activations correlated weakly to moderately with ΔPaw and moderately with ΔPes.

CONCLUSIONS

In five patients with weaning difficulties, low-load fast IMT provided a training stimulus similar to high-load IMT. Both yielded significantly higher training stimulus than low-load slow IMT and unsupported spontaneous breathing. These results should be considered in future trials comparing IMT with sham conditions.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT03240263 and NCT04658498.

Prediction of Weaning Outcomes in Mechanically Ventilated Patients Using Diaphragmatic Excursion With Tissue Doppler Imaging Variables of the Diaphragm

Background: Diaphragmatic excursion is a crucial predictor of extubation outcomes in subjects on mechanical ventilation. However, its measurement can be influenced by various factors, which leads to inconsistent optimal thresholds and accuracy. Tissue Doppler imaging variables of the diaphragm have been established as reliable indicators for predicting extubation outcomes. This study aimed to assess the predictive ability of combining diaphragmatic excursion with tissue Doppler imaging variables of the diaphragm in subjects on mechanical ventilation. Methods: This prospective observational study was conducted from April 2023 to April 2024, eligible subjects who underwent mechanical ventilation for > 48 h and successfully completed a 30-min spontaneous breathing test in the ICU of our center. Diaphragmatic excursion and tissue Doppler imaging variables (including peak contraction velocity, peak relaxation velocity, maximal contraction rate, and maximal relaxation rate) were assessed immediately after a 30-min spontaneous breathing trial. The subjects were categorized into successful extubation and failed extubation groups based on their extubation outcomes. Differences in diaphragmatic ultrasound variables between these groups were analyzed. Results: The study included 63 subjects in the successful extubation group and 28 subjects in the failed extubation group. The area under the receiver operating characteristic curve for diaphragmatic excursion in predicting successful extubation was determined as 0.79 (95% CI, 0.69 ∼ 0.89), with a sensitivity of 82.5% and a specificity of 75.0%. The combined area under the receiver operating characteristic curve for diaphragmatic excursion and tissue Doppler imaging variables (including peak contraction velocity and maximal relaxation rate) in predicting successful extubation was determined as 0.94 (95% CI, 0.88 ∼ 0.99), with a sensitivity of 92.1% and a specificity of 89.3%. Conclusions: Combining diaphragmatic excursion with tissue Doppler imaging variables of the diaphragm enhanced the prediction of extubation outcomes in the subjects on mechanical ventilation compared with diaphragmatic excursion alone.

Using weak signals to predict spontaneous breathing trial success: a machine learning approach

BACKGROUND

Weaning from mechanical ventilation (MV) is a key phase in the management of intensive care unit (ICU) patient. According to the WEAN SAFE study, weaning from MV initiation is defined as the first attempt to separate a patient from the ventilator and the success is the absence of reintubation (or death) within 7 days of extubation. Mortality rates increase with the difficulty of weaning, reaching 38% for the most challenging cases. Predicting the success of weaning is difficult, due to the complexity of factors involved. The many biosignals that are measured in patients during ventilation may be considered "weak signals", a concept rarely used in medicine. The aim of this research is to investigate the performance of machine learning (ML) models based on biosignals to predict spontaneous breathing trial success (SBT) using biosignals and to identify the most important variables.

METHODS

This retrospective study used data from two centers (Nice University Hospital, Archet and Pasteur) collected from 232 intensive care patients who underwent MV (149 successfully and 83 unsuccessfully) between January, 2020 and April, 2023. The study focuses on the development of ML algorithms to predict the success of the spontaneous breathing trial based on a combination of discrete variables and biosignals (time series) recorded during the 24 h prior to the SBT.

RESULTS

For the models tested, the best results were obtained with Support Vector Classifier model: AUC-PR 0.963 (0.936-0.970, p = 0.001), AUROC 0.922 (0.871-0.940, p < 0.001).

CONCLUSIONS

We found that ML models are effective in predicting the success of SBT based on biosignals. Predicting weaning from mechanical ventilation thus appears to be a promising area for the application of AI, through the development of multidimensional models to analyze weak signals.

Impact of comorbidities on management and outcomes of patients weaning from invasive mechanical ventilation: insights from the WEAN SAFE study

BACKGROUND

The impact of comorbidities on patients weaning from invasive ventilation is incompletely understood. We wished to understand the impact of the number and type of comorbidities on patients' weaning from invasive mechanical ventilation enrolled in the 'WorldwidE AssessmeNt of Separation of pAtients From ventilatory assistancE (WEAN SAFE) study.

METHODS

The study population consisted of patients enrolled in the WEAN SAFE study that commenced the weaning process. We categorized patients by the number of comorbidities (none, 1, 2, or 3 plus), and by specific comorbidity type. The primary outcome was the impact of comorbidities on delayed weaning and failed weaning from invasive MV. Secondary outcomes included the impact of comorbidities on ICU and hospital survival, and decisions to limit life-sustaining interventions.

RESULTS

Of 4523 patients in the study population, 1614 (35.7%) had one comorbidity, 889 (19.7%) had two comorbidities, 432 (9.6%) had three or more comorbidities, while 1562 (34.5%) had no comorbidities. The most frequently occurring comorbid conditions were respiratory (22%) and cardiovascular (11%). Patients with comorbidities were more likely to fail a separation attempt, more likely to receive an extubation attempt, and to require more than 1 extubation attempt. The proportion of patients with failed weaning from invasive MV increased progressively with increasing comorbidities. Neuromuscular comorbidities were associated with increased weaning duration. Weaning failure was increased with respiratory, hepatic, renal, neuromuscular, and immune dysfunction comorbidities. Hospital mortality rates increased progressively from 16% with no comorbidity to 34% with ≥ 3 comorbidities. Each specific comorbidity was independently associated with increased hospital mortality. The presence of comorbidities was associated with decisions to limit life sustaining interventions.

CONCLUSIONS

Most patients weaning from invasive ventilation have comorbidities, which are associated with higher weaning failure risk and worse outcomes. The adverse impact of comorbidities on the weaning outcomes and of the process are not explained by a less aggressive approach to weaning.

Development and validation of machine learning models for predicting extubation failure in patients undergoing cardiac surgery: a retrospective study

Patients with multiple comorbidities and those undergoing complex cardiac surgery may experience extubation failure and reintubation. The aim of this study was to establish an extubation prediction model using explainable machine learning and identify the most important predictors of extubation failure in patients undergoing cardiac surgery. Data from 776 adult patients who underwent cardiac surgery and were intubated for more than 24 h were obtained from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The primary endpoint was extubation failure according to the WIND criteria, with 205 patients experiencing extubation failure. The data was split into a training set (80%) and a test set (20%). The performance of the XGBoost algorithm was the highest (AUC 0.793, Mean Precision 0.700, Brier Score0.150), which was better than that of logistic regression (AUC 0.766, Mean Precision 0.553, Brier Score0.173) and random forest (AUC 0.791, Mean Precision 0.510, Brier Score 0.181). The most crucial predictor of extubation failure is the mean value of the anion gap in the 24 h before extubation. The other main features include ventilator parameters and blood gas indicators. By applying machine learning to large datasets, we developed a new method for predicting extubation failure after cardiac surgery in critically ill patients. Based on the predictive factors analyzed, internal environmental indicators and ventilation characteristics were important predictors of extubation failure. Therefore, these predictive factors should be considered when determining extubation readiness.

Similar Weaning Success Rate with High-Intensity and Sham Inspiratory Muscle Training: A Randomized Controlled Trial (IMweanT)

Rationale: Inspiratory muscle training (IMT) improves respiratory muscle function in patients with weaning difficulties. IMT protocols involve performing daily sets of breaths against external loads. However, the impact of IMT on weaning outcomes while incorporating sham control interventions remains unclear. Objectives: To compare the effects of a high-intensity IMT (Hi-IMT) intervention with a sham low-intensity (Lo-IMT) control group on weaning outcomes and respiratory muscle and pulmonary function 28 days after inclusion in patients with weaning difficulties. Methods: Both groups underwent daily IMT sessions until successful weaning or a maximum of 28 days. The Hi-IMT group (n = 44; 61% male; aged 57 ± 15 yr) performed maximal inspirations initiated from residual volume against an external load representing 30-50% of maximal inspiratory pressure (PImax), and the control group (n = 46; 52% male; aged 60 ± 12 yr) performed maximal inspirations against a load ⩽10% PImax. Measurements and Main Results: Training adherence (completed/planned sessions) was comparable between the groups (Hi-IMT, 77 ± 20%; Lo-IMT, 72 ± 17%; P = 0.25). Weaning success (64% Hi-IMT and 76% Lo-IMT; P = 0.43) and weaning duration (Hi-IMT, 45 ± 48 d; Lo-IMT, 37 ± 26 d; P = 0.33) were similar between groups. Both groups similarly improved PImax (Hi-IMT, +15 cm H2O [95% confidence interval (CI), 9, 20]; Lo-IMT, +14 cm H2O [95% CI, 9, 19]; P = 0.72). FVC improved more in the Hi-IMT group than in the Lo-IMT group (Hi-IMT, +0.33 L [95% CI, 0.22, 0.43]; Lo-IMT, +0.16 L [95% CI, 0.07, 0.25]; P = 0.04). Conclusions: Both high-intensity IMT and sham low-intensity IMT, with high adherence to the protocol, resulted in similar weaning success rates and pronounced improvements in maximal inspiratory muscle strength. Clinical trial registered with www.clinicaltrials.gov (NCT03240263).

Role of cardiac and lung ultrasonography in predicting weaning failure in patients with acute kidney injury requiring mechanical ventilation: A pilot study

PURPOSE

Acute Kidney Injury (AKI) has an incidence of 20-50 % in patients admitted in Intensive Care Unit. As weaning failure is associated with increased morbidity, its prediction and understanding of its physiological basis holds extreme importance in guided management and prognostication of these patients. We conducted this prospective, observational, single - center study to evaluate the efficacy of transthoracic echocardiography (TTE) and lung ultrasonography (LUS) in predicting weaning failure in patients with AKI requiring mechanical ventilation.

METHODS

We performed LUS and TTE before and 2 h after initiating spontaneous breathing trials (SBT) in 32 mechanically ventilated critically ill patients with AKI. Extubation was decided by an independent physician. LUS included global and anterior LUS scores. TTE included measurement of E/A and E/e' ratios to determine LV filling pressures.

RESULTS

Out of 32 patients included in this study, weaning failure was observed in 17 (n = 17, 53 %) patients (weaning success n = 15, 47%). Demographic and baseline laboratory parameters were comparable between the study groups. Fluid balance [+370 (250-530)] and SOFA score [8 (7-9)] on admission were significantly higher in weaning failure group (p < 0.001, p = 0.049). LUS scores and difference between LUS scores before and at the end of the SBT were significantly higher among the weaning failure group. The model consisting of baseline variables, SOFA score on the day of weaning and SBT induced changes in global lung score showed highest ability to predict weaning failure with AUC of 0.965, R2 = 61 %, p < 0.001.

CONCLUSION

In mechanically ventilated critically ill patients with AKI, LUS scores can predict weaning failure after SBT.

CTRI NUMBER

CTRI/2020/12/029565.

Prolonged T-Piece Spontaneous Breathing Trial and Extubation Outcomes in Patients Received Prolonged Mechanical Ventilation

Background and Objectives: Unassisted breathing through a T-piece was the most used spontaneous breathing trial (SBT) in endotracheal intubated prolonged mechanical ventilation (PMV) patients. However, the optimal duration of an SBT in PMV patients remains uncertain. In this study, we compared the extubation outcome between a 12 h T-piece SBT and a 24 h T-piece SBT in PMV patients. Materials and Methods: We reviewed the medical records of PMV patients who were extubated after passing a 12 h or 24 h T-piece SBT. The extubation, weaning, and hospital outcomes between the 12 h T-piece SBT group and the 24 h T-piece SBT group were compared. Kaplan-Meier survival plots and Cox proportional hazard models were used to evaluate the risk of extubation failure between groups. Results: In this study, 120 patients were extubated after passing the 12 h T-piece SBT and 234 patients were extubated after passing 24 h T-piece SBT. Patients in the 24 h T-piece SBT group had higher APACHE II score and lower Glasgow coma scale upon RCC arrival than patients in the 12 h T-piece SBT group. There was no difference in gender, age, or ventilator days before extubation between these two groups of patients. After extubation, patients in the 12 h T-piece SBT group and 24 h T-piece SBT group had similar extubation failure rates within 5 days (26.7% vs. 26.1%, p = 0.904). There was no difference in the RCC weaning rate (85% vs. 85.5%, p = 0.929) and hospital mortality rate (19.8% vs. 21.8%, p = 0.821) between the 12 h T-piece SBT group and the 24 h T-piece SBT group. Subgroup analysis showed that 24 h T-piece SBT was associated with a lower extubation failure rate in PMV patients with myocardial infarction or heart failure, but not in older PMV patients or those with cerebrovascular disease. Conclusions: The extubation and weaning outcomes were similar in PMV patients extubated after passing 12 h T-piece SBT or 24 h T-piece SBT.

Applying positive end-expiratory pressure before and during endotracheal tube removal versus extubation with concomitant aspiration: protocol for the randomised controlled multicentre EXSUPEEP trial

INTRODUCTION

The optimal method for removing the endotracheal tube (ETT) during extubation in the intensive care unit (ICU) remains uncertain. Two methods are described for removing the ETT in ICU, namely the 'Traditional technique' with continuous aspiration during cuff deflation and ETT removal; and the 'PEEP' method, which consists in applying positive end-expiratory pressure (PEEP) before and during cuff deflation and ETT removal. Our hypothesis is that applying PEEP during extubation in the ICU would improve clinical outcome.

METHODS AND ANALYSIS

This is a prospective, multicentre, randomised, open-label, controlled, superiority trial, analysed by intention-to-treat, comparing ETT removal with concomitant suction vs application of PEEP before and during ETT removal. In total, 424 patients will be recruited and randomly assigned in a 1:1 ratio to one of two groups, according to the strategy of ETT removal. The primary outcome is the number of days free from any mechanical ventilation within 28 days following extubation. Secondary outcomes include the reintubation rate up to 7 days after ETT removal, the cumulative duration of non-invasive ventilation up to 7 days following extubation, the rate of acute respiratory failure, the rate of acquired pneumonia during the first 7 days following ETT removal, the length of stay in ICU and in hospital and all-cause mortality at 28 days following ETT removal.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee 'CPP Ile de France II'. Patients will be included after providing written informed consent. The results will be submitted for publication in peer-reviewed journals, and in national and international congresses.

TRIAL REGISTRATION NUMBER

NCT05147636.

Tracheostomy: update on why, when and how

PURPOSE OF REVIEW

The aim of this review is to summarize available data, including the most recent ones, to help develop the best possible strategy regarding the use of tracheostomy in ICU patients requiring prolonged mechanical ventilation or who experience loss of airway-protecting mechanisms.

RECENT FINDINGS

Tracheostomy facilitates the weaning process by reducing the patient's work of breathing and increasing comfort. It thus allows for a reduction in sedation levels. It also helps with secretions clearance, facilitates disconnection from the ventilator, and enables earlier phonation, oral intake, and mobilization. Despite these advantages, tracheostomy does not reduce mortality and is associated with both early and late complications, particularly tracheal stenosis. The timing of tracheostomy remains a subject of debate, and only a personalized approach that considers each patient's specific characteristics can help find the best possible compromise between avoiding unnecessary delays and minimizing the risks of performing a needless invasive procedure. In the absence of contraindications, the percutaneous single dilator technique under fibroscopic guidance should be the first choice, but only if the team is properly trained.

SUMMARY

A step-by-step individualized approach based on the available evidence allows identifying the best strategy regarding the use of tracheostomy in ICU patients.

Mechanical power density, spontaneous breathing indexes, and weaning readiness following prolonged mechanical ventilation

INTRODUCTION

Evidence suggests that mechanical power (MP) normalized to dynamic compliance, which equals power density, may help identify prolonged ventilated patients at risk for spontaneous breathing trial (SBT) failure. This study compared MP density with traditional spontaneous breathing indexes to predict a patient's capacity to sustain a short trial of unassisted breathing.

METHODS

A prospective observational study on 186 prolonged ventilated, tracheotomized patients. We analyzed the first 30-min SBT upon weaning center admission, comparing MP density with spontaneous breathing indexes (e.g., predicted body weight normalized tidal volume (VT/PBW), rapid shallow breathing index (RSBI), and the integrative weaning index (IWI)) regarding SBT failure prediction, with diagnostic accuracy expressed as the area under the receiver operating characteristic curve (AUROC).

RESULTS

SBT failure occurred in 51 out of 186 patients (27 %), who demonstrated significantly lower dynamic compliance (median 29 mL/cmH2O [IQR 26-37] vs. 39 mL/cmH2O [33-45]) and higher MP density (5837 cmH2O2/min [4512-7758] vs. 2922 cmH2O2/min [2001-4094]) before SBT, as well as lower spontaneous VT/PBW (5.7 mL∗kg-1 [5.0-6.7] vs. 6.6 mL∗kg-1 [5.9-7.8]), higher RSBI (73 min-1∗L-1 [57-100] vs. 59 min-1∗L-1 [45-76]), and lower IWI (40 L2/cmH2O∗%∗min∗10-3 [27-50] vs. 63 L2/cmH2O∗%∗min∗10-3 [46-91]) after 5 min of unassisted breathing. MP density was more accurate at predicting SBT failures (AUROC 0.86 [95%CI 0.80-0.91]) than VT/PBW (0.58 [0.50-0.65]), RSBI (0.54 [0.47-0.61]), or IWI (0.66 [0.58-0.73])).

CONCLUSIONS

MP density as a readiness criterion was more accurate at predicting weaning trial failures in prolonged ventilated, tracheotomized patients than traditional indexes assessed during unassisted breathing.

Oxygen consumption, effort, and weaning in the mechanically ventilated patient in the intensive care unit: The extubate study: A protocol for an observational study

PURPOSE

The spontaneous breathing trial (SBT) is often performed to determine whether the patient can be extubated with a minimal risk of failure. The rapid shallow breathing index (RSBI) is an important parameter used in an SBT. However, weaning failure rates are between 15 and 20 %. Because of the high incidence of extubation failure a search for a better parameter is warranted. The aim of this study is to investigate whether oxygen consumption, pressure-time product, work of breathing and pressure swings predict weaning failure.

METHODS

This is a single-center, prospective observational study conducted at the Leiden University Medical Center. Adult patients undergoing an SBT as per the ruling protocol in the LUMC will be included. Measurements of oxygen consumption, pressure-time product, work of breathing and pressure swings will be continuously recorded during 10 min prior, during and 10 min after the SBT. Data collection will not interfere with clinical decision making. The primary outcome is the ability of these parameters to predict extubation success or failure.

DISCUSSION

Patient enrollment started in January 2024 and inclusions are expected to be complete in January 2026. Patient's risk and burden are minimal. We hypothesize that patients who fail extubation will have higher absolute baseline efforts but will not have the potential to increase those efforts when subjected to an SBT.

TRIAL REGISTRATION

The study is retrospectively registered at ClinicalTrials.gov under identifier NCT06391424, submitted on 2024-04-30.

Assessment of Respiratory Muscles, Lung Parenchyma, and Cardiac Function by Ultrasound for Predicting Weaning Failure in Critically Ill Adults: A Prospective Observational Study

OBJECTIVES

The parasternal intercostal muscle activity, a marker of accessory muscle usage, is found to correlate inversely with the pressure-generating capacity of the diaphragm and level of support of mechanical ventilation. The primary objective of our study was to determine whether the parasternal intercostal muscle thickening fraction (PMTF) measured by ultrasonography can predict weaning. We also evaluated whether addition of lung ultrasound score and echocardiographic assessment can add on to predicting weaning failure.

METHODS

This prospective observational study conducted in a mixed medical-surgical intensive care unit, included 60 adult patients who were eligible for a spontaneous breathing trial (SBT) after being invasively mechanically ventilated for more than 48 hours. Ultrasound of respiratory muscles, lung parenchyma, and echocardiographic assessment were performed before and after 120 minutes of SBT. Parasternal intercostal muscles were imaged with a high frequency linear probe on the right second intercostal space 5 cm lateral to the sternal margin. PMTF was calculated as (maximum-minimum thickness)/minimum thickness.

RESULTS

Among 60 patients, SBT failure was seen in 11 patients and extubation failed in 8 patients. PMTF (%) was significantly higher in the weaning failure group (13.33 [8.33-19.05]) as compared to patients with successful weaning (6.67 [6.06-11.54]). Diaphragmatic thickening fraction (DTF) correlated inversely to PMTF in patients with weaning failure. A pre-SBT PMTF cut-off of ≥7.7% and post-SBT cut-off of ≥15.38% were good predictors of weaning failure and extubation failure, respectively.

CONCLUSIONS

PMTF has good discriminatory power to predict weaning outcomes (area under the receiver operating characteristic curve: 0.74 [0.59-0.88]). Pre-SBT PMTF had similar power as DTF to predict weaning failure.

Clinical utility of rapid shallow breathing index in predicting successful weaning: secondary analysis of the COBRE-US trial

OBJECTIVE

To assess the predictive capacity of the Rapid Shallow Breathing Index (RSBI) for success in spontaneous breathing trials (SBT) and extubation in critically ill patients. We evaluated the association between RSBI, duration of mechanical ventilation, and ventilator-free time at 28 days.

DESIGN

Prospective multicenter observational study. Secondary analysis of the COBRE-US study.

SETTING

Intensive care unit (ICU).

PATIENTS OR PARTICIPANTS

367 patients in the ICU receiving invasive mechanical ventilation.

INTERVENTIONS

Assessment of RSBI at the end of SBT.

MAIN VARIABLES OF INTEREST

RSBI, SBT, duration of mechanical ventilation, and ventilator-free time at 28 days were evaluated.

RESULTS

367 patients in the ICU under invasive mechanical ventilation were evaluated, of whom 59.7% were male with a median age of 61 years (IQR: 49-72). A total of 456 SBT were conducted with a success rate of 76.5%. RSBI had a ROC-curve of 0.53 for SBT success and a ROC-curve of 0.48 for extubation. The Spearman correlation coefficient between RSBI and duration of ventilation was 0.117 (p = 0.026), while for ventilator-free time at 28 days, it was -0.116 (p = 0.028).

CONCLUSIONS

RSBI was not associated with success in SBT or extubation, regardless of the cutoff point used. Correlation analyses showed weak associations between RSBI and both the duration of ventilation and ventilator-free time at 28 days.

Optimizing Sedation Strategies in the Cardiac ICU: Induction, Maintenance and Weaning

PURPOSE OF REVIEW

We aim to summarize the available literature guiding tailored sedation practices for specific conditions encountered in the Cardiovascular Intensive Care Unit (CICU).

RECENT FINDINGS

Data specific for the CICU population is lacking. Preclinical data and observational studies guide sedation approaches for specific pathologies that we have used to generate a guideline for sedative choice for various scenarios. We discuss the challenges associated with extubation and highlight the importance of spontaneous breathing trials and role of non invasive ventilation. Understanding the underlying pathology and the effects of sedation and positive pressure ventilation is the base to guide induction and sedation management for patients in the CICU. There is a pressing need for further research to generate high quality clinical data to improve sedation techniques in the CICU.

Early weaning from invasive mechanical ventilation via high-flow nasal oxygen versus conventional weaning in patients with hypoxemic respiratory failure: a prospective randomized controlled study

OBJECTIVE

Although the efficacy of high-flow nasal oxygen therapy in delaying or avoiding intubation in patients with hypoxemic respiratory failure has been studied, its potential for facilitating early weaning from invasive mechanical ventilation remains unexplored.

METHODS

In this randomized controlled trial, 80 adults with acute hypoxemic respiratory failure requiring invasive mechanical ventilation for > 48 hours were enrolled and divided into two groups: conventional weaning and early weaning via high-flow nasal oxygen. In the conventional weaning group, the spontaneous breathing trial was performed after the PaO2/FiO2 ratio was ≥ 200, whereas in the high-flow nasal oxygen group, the spontaneous breathing trial was conducted earlier when the PaO2/FiO2 ratio was 150 - 200. Following each successful spontaneous breathing trial, patients were extubated and put on oxygen supplementation via a venturi mask or high-flow nasal oxygen on the basis of their group allocation. The primary objective was to compare extubation failure (reintubation within 48 hours). The secondary objectives were to compare total invasive mechanical ventilation, oxygen requirement and sedation requirement days, ventilator-associated pneumonia incidence, invasive mechanical ventilation-free days, intensive care unit length of stay, and intensive care unit all-cause mortality.

RESULTS

Extubation failure was not significantly different between the high-flow nasal oxygen group and the conventional weaning group [12.5% versus 25%, respectively; odds ratio (95%CI) 0.5 (0.19 - 1.33)] (p = 0.25). Early weaning from invasive mechanical ventilation via high-flow nasal oxygen was associated with significantly increased invasive mechanical ventilation-free days and total oxygen requirement days (p = 0.02 and p = 0.01, respectively). No significant between-group differences were observed in total invasive mechanical ventilation days, ventilator-associated pneumonia incidence, intensive care unit length of stay, sedation duration, or all-cause mortality.

CONCLUSION

Among patients with acute hypoxemic respiratory failure, early extubation with high-flow nasal oxygen is a feasible and superior alternative to the conventional method of weaning, as it increases the number of invasive mechanical ventilation-free days.

Impact of frailty and older age on weaning from invasive ventilation: a secondary analysis of the WEAN SAFE study

OBJECTIVE

To understand the impact of both frailty and chronologic age on outcomes of weaning from invasive mechanical ventilation (MV).

METHODS

The study population consisted of patients enrolled in the 'WorldwidE. AssessmeNt of Separation of pAtients From ventilatory assistancE (WEAN SAFE) study. We defined 4 non-overlapping groups, namely: 'frail' (clinical frailty scale [CFS] score > 4; age < 80 years); 'elderly' (CFS ≤ 4; age ≥ 80y), 'frail \elderly' (CFS > 4; age ≥ 80 years), and a 'not frail or elderly' population. The primary outcome was the impact of frailty and older age on delayed weaning and failed weaning from invasive MV. Secondary outcomes included the impact of frailty and age on ICU and hospital survival.

RESULTS

In the study population, 760 (17%) were frail, while 360 (8%) were elderly, 197 (4%) were frail and elderly, while 3,176 (70%) were not frail or elderly. The frail and elderly cohorts were more likely to be female, had hypoxemic/hypercapnic respiratory failure or sepsis, and had more comorbidities. The proportion of delayed weaning and of failed weaning from invasive MV was significantly higher in the frail (28 and 23%), the elderly (25 and 19%), and the frail and elderly groups (22% and 25%), compared to the not frail or elderly population (12% and 13%, P < 0.01). ICU and hospital mortality was higher in the frail (21 and 33%), the elderly (19 and 31%), and the frail and elderly groups (26 and 46%), compared to the not frail or elderly population (12% and 18%, P < 0.001). In multivariate analyses, there was an independent association between frailty and delayed weaning initiation and weaning failure. Old age was independently associated with risk of weaning failure.

CONCLUSIONS

Frailty status had a more consistent impact than older age on weaning outcomes. However, overall outcomes in these cohorts are encouraging once separation attempts have been initiated.

Value of combining lung ultrasound score with oxygenation and functional indices in determining weaning timing for critically ill pediatric patients

OBJECTIVE

This study aims to investigate the predictive effectiveness of bedside lung ultrasound score (LUS) in conjunction with rapid shallow breathing index (RSBI) and oxygenation index (P/F ratio) for weaning pediatric patients from mechanical ventilation.

METHODS

This was a retrospective study. Eighty-two critically ill pediatric patients, who were admitted to the Pediatric Intensive Care Unit (PICU) and underwent mechanical ventilation from January 2023 to April 2024, were enrolled in this study. Prior to weaning, all patients underwent bedside LUS, with concurrent measurements of their RSBI and P/F ratio. Patients were followed up for weaning outcomes and categorized into successful and failed weaning groups based on these outcomes. Differences in clinical baseline data, LUS scores, RSBI and P/F ratios between the two groups were compared. The predictive value of LUS scores, RSBI and P/F ratios for weaning outcomes was assessed using receiver operating characteristic (ROC) curves and the area under the curve (AUC).

RESULTS

Out of the 82 subjects, 73 (89.02%) successfully weaned, while 9 (10.98%) failed. No statistically significant differences were observed in age, gender, BMI, and respiratory failure-related comorbidities between the successful and failed weaning groups (P > 0.05). Compared to the successful weaning group, the failed weaning group exhibited longer hospital and intubation durations, higher LUS and RSBI, and lower P/F ratios, with statistically significant differences (P < 0.05). An LUS score ≥ 15.5 was identified as the optimal cutoff for predicting weaning failure, with superior predictive power compared to RSBI and P/F ratios. The combined use of LUS, RSBI and P/F ratios for predicting weaning outcomes yielded a larger area under the curve, indicating higher predictive efficacy.

CONCLUSION

The LUS demonstrates a high predictive value for the weaning outcomes of pediatric patients on mechanical ventilation.

Ventilation distribution during spontaneous breathing trials predicts liberation from mechanical ventilation: the VISION study

BACKGROUND

Predicting complete liberation from mechanical ventilation (MV) is still challenging. Electrical impedance tomography (EIT) offers a non-invasive measure of regional ventilation distribution and could bring additional information.

RESEARCH QUESTION

Whether the display of regional ventilation distribution during a Spontaneous Breathing Trial (SBT) could help at predicting early and successful liberation from MV.

STUDY DESIGN AND METHODS

Patients were monitored with EIT during the SBT. The tidal image was divided into ventral and dorsal regions and displayed simultaneously. We explored the ventral-to-dorsal ventilation difference in percentage, and its association with clinical outcomes. Liberation success was defined pragmatically as passing SBT followed by extubation within 24 h without reintubation for 7 days. Failure included use of rescue therapy, reintubation within 7 days, tracheostomy, and not being extubated within 24 h after succesful SBT. A training cohort was used for discovery, followed by a validation cohort.

RESULTS

Among a total of 98 patients analyzed, 85 passed SBT (87%), but rapid liberation success occurred only in 40; 13.5% of extubated patients required reintubation. From the first minutes to the entire SBT duration, the absolute ventral-to-dorsal difference was consistently smaller in liberation success compared to all subgroups of failure (p < 0.0001). An absolute difference at 5 min of SBT > 20% was associated with failure of liberation, with sensitivity and specificity of 71% and 78% and positive predictive value 81% in a validation cohort.

CONCLUSION

During SBT, a large ventral-to-dorsal difference in ventilation indicated by EIT may help to rapidly identify patients at risk of liberation failure.

Exploring Extubation Readiness in Guillain-Barré Syndrome: A Case Report and Literature Review

Guillain-Barré Syndrome (GBS) is an acute immune-mediated polyneuropathy causing rapidly progressive muscle weakness and often respiratory failure, requiring mechanical ventilation in 30% of cases. Successful weaning and extubation are crucial, focusing on readiness for spontaneous breathing trials, optimal timing, and minimizing complications such as ventilator-associated pneumonia and extubation failure. This case report describes an 83-year-old male with multiple comorbidities who was intubated after his negative inspiratory force dropped below -30 cm H₂O and treated with plasmapheresis, leading to partial improvement. Despite not meeting standard extubation criteria, he was successfully extubated, maintained stable respiratory function, and was safely discharged. This case highlights the challenges of extubation in GBS patients, where advanced age, decreased physiological reserve, and comorbidities increase the risks of prolonged intubation and complications. This case also highlights the need for individualized extubation strategies in GBS, particularly in elderly patients who may not meet standard criteria. Tailored approaches can still lead to successful outcomes. Based on our institutional experience, we propose factors that predict the success or failure of extubation in these patients. Further research is needed to refine predictive markers and improve extubation success in this population, ultimately enhancing outcomes and reducing ICU and hospital stays.

Best clinical model predicting extubation failure: a diagnostic accuracy post hoc analysis

PURPOSE

Predicting extubation failure remains a clinical challenge. This study aimed to determine diagnostic accuracy of models used at the bed side.

METHODS

Post hoc analysis of 2341 patients at all risk included in five multicenter randomized trials. Diagnostic accuracy of three clinical prediction models was compared: 3-factors model including age > 65y, chronic heart or pulmonary disease; 4-factors model adding prolonged mechanical ventilation; and 11-factors model including age > 65 years, ≥ 2 comorbidities, prolonged mechanical ventilation, acute heart failure as the primary indication for mechanical ventilation, moderate-to-severe chronic obstructive pulmonary disease, APACHE II score > 12 on extubation day, airway patency problems, inability to deal with respiratory secretions, not simple weaning, obesity, or hypercapnia at the end of the spontaneous breathing trial. Crude and adjusted for spontaneous breathing trial (SBT) models were compared for all-cause reintubation at 7 days using Youden and Kappa indexes.

RESULTS

The 3-factors model had a very low global prediction capability (Youden index 0.08 and Kappa index 0.04); the 4-factors and 11-factors models had low global prediction capability (Youden index 0.12 and 0.16, and Kappa index 0.06 and 0.07, respectively). Aggressive SBT strategies (pressure support ≥ 7 cm H2O with or without positive end-expiratory pressure) were associated with extubation failure risk (p < 0.001). All adjusted models had low diagnostic capability (0.08/0.03, 0.07/0.03, and 0.06/0.02 respectively).

CONCLUSION

Based on these results, the 3-factors model reported a very low diagnostic accuracy, and the 4 or 11-factors models showed similar low accuracy. No improvement was observed after adjusting for other aspects of weaning.

Incidence, Risk Factors, and Long-Term Outcomes for Extubation Failure in ICU in Patients With Obesity: A Retrospective Analysis of a Multicenter Prospective Observational Study

BACKGROUND

To our knowledge, no large observational study has compared the incidence and risk factors for extubation failure within 48 h and during ICU stay in the same cohort of unselected critically ill patients with and without obesity.

RESEARCH QUESTION

What are the incidence and risk factors of extubation failure in patients with and without obesity?

STUDY DESIGN AND METHODS

In the prospective multicenter observational Practices and Risk Factors for Weaning and Extubation Airway Failure in Adult Intensive Care Unit: A Multicenter Trial (FREEREA) study in 26 ICUs, the primary objective was to compare the incidence of extubation failure within 48 h in patients with and without obesity. Secondary objectives were to describe and to identify the independent specific risk factors for extubation failure using first a logistic regression model and second a decision tree analysis.

RESULTS

Of 1,370 extubation procedures analyzed, 288 (21%) were performed in patients with obesity and 1,082 (79%) in patients without obesity. The incidence of extubation failure within 48 h among patients with or without obesity was 23 of 288 (8.0%) vs 118 of 1,082 (11%), respectively (unadjusted OR, 0.71; 95% CI, 0.45-1.13; P = .15); alongside patients with obesity receiving significantly more noninvasive ventilation [87 of 288 (30%) vs 233 of 1,082 (22%); P = .002] and physiotherapy [165 of 288 (57%) vs 527 of 1,082 (49%); P = .02] than patients without obesity. Risk factors for extubation failure also differed according to obesity status: female sex (adjusted OR, 4.88; 95% CI, 1.61-13.9; P = .002) and agitation before extubation (adjusted OR, 6.39; 95% CI, 1.91-19.8; P = .001) in patients with obesity, and absence of strong cough before extubation (adjusted OR, 2.38; 95% CI, 1.53-3.84; P = .0002) and duration of invasive mechanical ventilation before extubation (adjusted OR, 1.03/d; 95% CI, 1.01-1.06; P = .01) in patients without obesity. The decision tree analysis found similar risk factors.

INTERPRETATION

Our findings indicate that anticipation and application of preventive measures for patients with obesity before and after extubation led to similar rates of extubation failure among patients with and without obesity.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02450669; URL: www.

CLINICALTRIALS

gov.

Effect of sleep quality on weaning from mechanical ventilation: A scoping review

Introduction

Mechanically ventilated patients have disturbed sleep.

Aim of the study

To explore whether there is a relationship between successful or unsuccessful weaning of patients and their sleep quality and circadian rhythm.

Materials and Methods

A scoping review. The search process involved four online databases: CINAHL, MEDLINE, ProQuest, and ScienceDirect. Original studies published between January 2020 and October 2022 were included in the review.

Results

Six studies met the inclusion criteria. These studies showed that patients with difficult weaning were more likely to have atypical sleep, shorter REM sleep, and reduced melatonin metabolite excretion. Muscle weakness was an independent factor associated with prolonged weaning from mechanical ventilation and was significantly more frequent in patients with atypical sleep. Heterogeneous patient samples and the methodology of the studies hamper a clear interpretation of the results.

Conclusions

A relationship was found between abnormal sleep patterns, reduced melatonin metabolite (6-sulfa-toxymelatonin) excretion, and unsuccessful weaning. However, the causality is not clear from the existing research.

Contribution and evolution of respiratory muscles function in weaning outcome of ventilator-dependent patients

BACKGROUND

The present study was designed to investigate the evolution and the impact of respiratory muscles function and limb muscles strength on weaning success in prolonged weaning of tracheotomized patients. The primary objective was to determine whether the change in respiratory muscles function and limb muscles strength over the time is or is not associated with weaning success.

METHODS

Tracheotomized patients who were ventilator dependent upon admission at a weaning center were eligible. Diaphragm function was assessed with the phrenic nerve stimulation technique and with ultrasound to measure the diaphragm thickening fraction (TFdi) and diaphragm excursion (EXdi). Global respiratory muscle function was assessed with the maximal inspiratory pressure (MIP) and the forced vital capacity (FVC). Limb muscle strength was measured with the Medical Research Council Score (MRC). Measurements were made on a weekly basis. Patients were compared according to their outcome at discharge: complete weaning, partial weaning or death.

RESULTS

Among the 60 patients who were enrolled, 30 patients finally achieved complete weaning, 20 had partial weaning and 10 died. At 6 months, 6 patients were lost of follow-up, 33 achieved complete weaning, 10 had partial weaning and 11 died. In median, 2 (1-9) assessments were performed per patient. Diaphragm dysfunction was present in all patients with a median Ptr,stim of 5.5 cmH2O (3.0-7.5). Ptr,stim, MIP, TFdi and EXdi at admission were not different between patients who achieved complete weaning and their counterparts. At discharge of the weaning center, MIP, Ptr,stim and EXdi significantly increased in patients who achieved complete weaning. The MRC score significantly increased only in patients with complete weaning. At discharge, diaphragm dysfunction was highly prevalent even in patients with complete weaning (Ptr,stim < 11 cmH2O in n = 11 (37%)).

CONCLUSION

Respiratory muscle function and limb muscles strength are severely impaired in patients with prolonged weaning from mechanical ventilation. Significant improvement of diaphragm ultrasound indices was associated with successful weaning from mechanical ventilation and ICU-acquired weakness upon admission was significantly associated with good outcome suggesting that it was an amendable determinant of weaning failure in this population.

Heart Rate Variability During Weaning from Invasive Mechanical Ventilation: A Systematic Review

Background: The role of Heart Rate Variability (HRV) indices in predicting the outcome of the weaning process remains a subject of debate. The aim of this study is to investigate HRV analysis in critically ill adult patients undergoing weaning from invasive mechanical ventilation (IMV). Methods: The protocol of this systematic review was registered with PROSPERO (CRD42024485800). We searched PubMed and Scopus databases from inception till March 2023 to identify randomized controlled trials and observational studies investigating HRV analysis in critically ill adult patients undergoing weaning from invasive mechanical ventilation. Our primary outcome was to investigate HRV changes occurring during the weaning from IMV. Results: Seven studies (n = 342 patients) were included in this review. All studies reported significant changes in at least one HRV parameter. The indices Low Frequency (LF), High Frequency (HF), and LF/HF ratio seem to be the most promising in predicting the outcome of weaning with reliability. Some HRV indices showed modification in response to different ventilator settings or modalities. Conclusions: Available data report HRV modifications during the process of weaning and suggest a promising role of some HRV indices in predicting weaning outcomes in critically ill patients. Point-of-care HRV monitoring systems might help to early detect patients at risk of weaning failure.

Rehabilitation effects of acupuncture on the diaphragmatic dysfunction in respiratory insufficiency: A systematic review and meta-analysis

INTRODUCTION

Mechanical ventilation after respiratory insufficiency can induce diaphragm dysfunction through various hypothesized mechanisms. In this study, we evaluated the rehabilitative effect of acupuncture on diaphragm function in patients with respiratory insufficiency using meta-analysis and summarised the rules of acupoints through association rules analysis.

METHODS

Articles (published from January 2000 to February 2024) were retrieved from the following databases: PubMed, Cochrane Library, Embase, Web of Science, CNKI, VIP, SinoMed, and Wanfang. Two researchers conducted literature selection, data extraction, and statistical analysis independently. The risk of bias was assessed utilizing the Physical Therapy Evidence Database (PEDro) scale. The meta-analysis was performed with RevMan 5.4 software, and the quality of each outcome evidence was assessed via the online software GRADEpro GDT. The regularity of acupoint selection was summarized using association rules analysis. This study is registered on PROSPERO, number CRD42024526705.

RESULTS

Eleven articles were eventually included, all of which were of low to moderate quality. Results of the meta-analysis showed a significant increase in diaphragmatic thickening fraction (MD 3.40 [1.52, 5.27]) and diaphragmatic excursion (MD 0.95 [0.58, 1.31]) in patients with respiratory insufficiency after acupuncture treatment. Also, OI (MD 28.52 [15.93, 41.11]) and PaO2 (MD 7.18 [2.22, 12.13]) were significantly elevated and PaCO2 (MD -6.94 [-12.30, -1.59]) was decreased. Mechanical ventilation time (MD-1.86 [-2.28, -1.45]) was also significantly improved. The overall quality of the outcome evidence is deemed moderate. Association rules analysis showed that ST36, RN4, RN6, and others are core acupoints for the treatment of diaphragmatic dysfunction in patients with respiratory insufficiency by acupuncture.

CONCLUSION

Acupuncture shows potential in the rehabilitation of patients with respiratory insufficiency and may serve as a complementary and alternative therapy for related conditions. We suggest the use of ST36 as a core acupoint, in combination with other acupoints. Due to the potential publication bias and high heterogeneity of the current data, further high-quality RCTs are needed to confirm these findings.

Weaning of non COPD patients at high-risk of extubation failure assessed by lung ultrasound: the WIN IN WEAN multicentre randomised controlled trial

BACKGROUND

Postextubation respiratory failure (PRF) frequently complicates weaning from mechanical ventilation and may increase morbidity/mortality. Noninvasive ventilation (NIV) alternating with high-flow nasal oxygen (HFNO) may prevent PRF.

METHODS

Ventilated patients without chronic obstructive pulmonary disease (COPD) and at high-risk of PRF defined as a lung ultrasound score (LUS) ≥ 14 assessed during the spontaneous breathing trial, were included in a French-Chinese randomised controlled trial. PRF was defined by 2 among the following signs: SpO2 < 90%; Respiratory rate > 30 /min; hypercapnia; haemodynamic and/or neurological disturbances of respiratory origin. In the intervention group, prophylactic NIV alternating with HFNO was administered for 48 h following extubation. In the control group, conventional oxygen was used. Clinicians were informed on the LUS in the intervention group, those in the control group remained blind. The primary outcome was the incidence of PRF 48 h after extubation. Secondary outcomes were incidence of PRF and reintubation at day 7, number of ventilator-free days at day 28, length of ICU stay and mortality at day 28 and 90.

RESULTS

Two hundred and forty patients were randomised and 227 analysed (intervention group = 128 and control group = 99). PRF at H48 was reduced in the intervention group compared to the control group: relative risk 0.52 (0.31 to 0.88), p = 0.01. The benefit persisted at day 7: relative risk 0.62 (0.44 to 0.96), p = 0.02. Weaning failure imposing reconnection to mechanical ventilation was not reduced. In patients who developed PRF and were treated by rescue NIV, reintubation was avoided in 44% of control patients and in 12% of intervention patients (p = 0.008). Other secondary outcomes were not different between groups. From a resource utilisation standpoint, prophylactic NIV alternating with HFNO was more demanding and costly than conventional oxygen with rescue NIV to achieve same clinical outcome.

CONCLUSIONS

Compared to conventional oxygenation, prophylactic NIV alternating with HFNO significantly reduced postextubation respiratory failure but failed to reduce reintubation rate and mortality in patients without COPD at high risk of extubation failure. Prophylactic NIV alternating with HFNO was as efficient as recue NIV to treat postextubation respiratory failure.

Poor sleep quality is a risk factor for adverse clinical outcomes in patients with acute aortic dissection: A prospective cohort study

The decrease in sleep quality leads to an increased risk of cardiovascular disease and is closely related to the prognosis of various diseases. However, the relationship between preoperative sleep quality and postoperative clinical outcomes in patients with acute aortic dissection is still unclear. We aimed to assess the relationship between sleep quality and the clinical outcomes of acute aortic dissection. We assessed participants' sleep quality and the clinical outcomes of acute aortic dissection, which included prolonged mechanical ventilation, postoperative delirium, in-hospital death, continuous renal replacement therapy, intensive care unit stay time, and length of stay. Patients were divided into good sleep quality group (n = 103) and poor sleep quality group (n = 113). Postoperative delirium, in-hospital death, prolonged mechanical ventilation and intensive care unit stay time were significantly increased in the poor sleep quality group when compared with the good sleep quality group (p < 0.05). Multivariate regression analysis showed that the poorer sleep quality, the greater the risk of in-hospital death (odds ratio = 3.451, 95% confidence interval 1.19-10.004) and prolonged mechanical ventilation (odds ratio = 6.302, 95% confidence interval 3.105-12.791), and the longer intensive care unit stay time (β = 62.37, 95% confidence interval 22.411-102.329). In addition, the higher the incidence of smoking history (odds ratio = 7.417, 95% confidence interval 2.425-22.684), poor sleep quality (odds ratio = 11.59, 95% confidence interval 3.844-34.942) and postoperative delirium (odds ratio = 5.1, 95% confidence interval 1.793-14.504), the greater the risk of prolonged mechanical ventilation. Our findings revealed that poor sleep quality may be a risk factor for adverse clinical outcomes of acute aortic dissection. Rapid assessment of self-reported sleep quality may be a simple and effective way to identify patients with acute aortic dissection who are at high risk for prolonged mechanical ventilation.

Diaphragmatic Dynamics Assessed by Bedside Ultrasound Predict Extubation in the Intensive Care Unit: A Prospective Observational Study

Background

This study aims to evaluate the predictive value of bedside ultrasound evaluation of diaphragmatic dynamics in determining successful extubation outcomes for patients eligible for weaning.

Methods

This prospective observational study was conducted on patients who were mechanically ventilated and ready for weaning during the spontaneous breathing trial (SBT). The diaphragm contraction and motion-related parameters of patients such as end inspiratory diaphragm thickness (DT-insp), end respiratory diaphragm thickness (DT-exp), diaphragm thickening fraction (DTF), diaphragmatic thickening fraction rapid shallow breathing index (DTF-RSBI), diaphragmatic excursion (DE), diaphragmatic excursion rapid shallow breathing index (DE-RSBI) were recorded and the association with failure in ventilatory extubation was analyzed. A receiver operating characteristic (ROC) curve was conducted to analyze the prediction of successful weaning.

Results

Out of 95 patients, 14 (14.74%) died, and 68 (71.58%) were successfully extubated. There were significant differences between the two groups in all parameters except DT-exp. The results indicated that duration of mechanical ventilation (OR = 0.850, 95% CI: 0.770-0.938, P = 0.001), DTF (OR = 1.214, 95% CI: 1.108-1.330, P = 0.000), DTF-RSBI (OR = 0.917, 95% CI: 0.880-0.954, P = 0.000), DE (OR = 127.02, 95% CI: 15.004-1075.291, P = 0.000), DE-RSBI (OR = 0.752, 95% CI: 0.657-0.861, P = 0.000) had predictive value for weaning. DTF and DE had a high sensitivity of 91.18%, 100%, respectively. Whereas, duration of mechanical ventilation, DTF-RSBI, DE-RSBI showed a high specificity of 81.48,85.19%, 81.48%. Considering all the above factors, the sensitivity was 88.24% and the specificity was 88.89%.

Conclusion

Bedside ultrasound assessment of diaphragmatic parameters enables the detection of diaphragmatic dysfunction, thus proving valuable in predicting extubation success and facilitating a favorable weaning outcome.

Predictors of weaning failure in ventilated intensive care patients: a systematic evidence map

BACKGROUND

Ventilator weaning is of great importance for intensive care patients in order to avoid complications caused by prolonged ventilation. However, not all patients succeed in weaning immediately. Their spontaneous breathing may be insufficient, resulting in extubation failure and the subsequent need for reintubation. To identify patients at high risk for weaning failure, a variety of potential predictors has already been examined in individual studies and meta-analyses over the last decades. However, an overview of all the predictors investigated is missing.

AIM

To provide an overview of empirically investigated predictors for weaning failure.

METHODS

A systematic evidence map was developed. To this end, we conducted a systematic search in the Medline, Cochrane, and CINAHL databases in December 2023 and added a citation search and a manual search in June 2024. Studies on predictors for weaning failure in adults ventilated in the intensive care unit were included. Studies on children, outpatients, non-invasive ventilation, or explanatory factors of weaning failure were excluded. Two reviewers performed the screening and data extraction independently. Data synthesis followed an inductive approach in which the predictors were thematically analyzed, sorted, and clustered.

RESULTS

Of the 1388 records obtained, 140 studies were included in the analysis. The 112 prospective and 28 retrospective studies investigated a total of 145 predictors. These were assigned to the four central clusters 'Imaging procedures' (n = 22), 'Physiological parameters' (n = 61), 'Scores and indices' (n = 53), and 'Machine learning models' (n = 9). The most frequently investigated predictors are the rapid shallow breathing index, the diaphragm thickening fraction, the respiratory rate, the P/F ratio, and the diaphragm excursion.

CONCLUSION

Predictors for weaning failure are widely researched. To date, 145 predictors have been investigated with varying intensity in 140 studies that are in line with the current weaning definition. It is no longer just individual predictors that are investigated, but more comprehensive assessments, indices and machine learning models in the last decade. Future research should be conducted in line with international weaning definitions and further investigate poorly researched predictors. Registration, Protocol: https://doi.org/10.17605/OSF.IO/2KDYU.

A cluster randomized trial on inspiratory effort-targeted pressure support adjustment strategy in patients undergoing assisted mechanical ventilation: protocol for the IT-PSV study

Background

Pressure support ventilation (PSV) is one of the most frequently used ventilator modes in the intensive care unit (ICU). The successful implementation of PSV depends on matching the patient's inspiratory effort with the ventilator support. In clinical practice, the pressure support level is usually set and adjusted according to tidal volume and respiratory rate. However, these parameters may not fully represent the patient's effort. Previous studies have shown that pressure muscle index (PMI), which is measured as the difference between the peak and plateau airway pressure during an end-inspiratory airway occlusion, could reliably determine the low and high inspiratory effort during PSV. Herein we present the study protocol for the Inspiratory effort-Targeted Pressure Support Ventilation (IT-PSV) trial to determine the effect of a PMI-targeted pressure support setting strategy on clinical outcomes in patients undergoing PSV.

Methods and analysis

This is a cluster randomized controlled trial. Sixteen ICUs in academic hospitals will be included, eight of which will be randomly allocated to the PMI-targeted group and eight to the tidal volume/respiratory rate-targeted group. Before the initiation of the study, a four-week comprehensive training program, which includes courses of PSV initiation, pressure support adjustment, and weaning process, will be conducted for all staff in the participating ICUs. Adult patients with acute hypoxic respiratory failure and undergoing PSV within 24 h will be included. Pressure support setting and adjustment will follow the strategy according to the grouping. The primary outcome is the ventilator-free days at 28 days after enrollment. The patients will be followed up until successful weaning or separation of mechanical ventilation, death, hospital discharge, or until 28 days after randomization, whichever comes first.

Discussion

The IT-PSV trial will examine the effect of an inspiratory effort-targeted PSV setting strategy on the duration of mechanical ventilation. If positive, it will provide a new physiological-based PSV management that could potentially facilitate protective assisted ventilation.

Clinical trial registration

ClinicalTrials.gov, identifier NCT06526598.

Transvenous phrenic nerve stimulation reduces diaphragm injury during controlled mechanical ventilation in a preclinical model of ARDS

Patients with acute respiratory distress syndrome (ARDS) require periods of deep sedation and mechanical ventilation, leading to diaphragm dysfunction. Our study seeks to determine whether the combination of temporary transvenous diaphragm neurostimulation (TTDN) and mechanical ventilation changes the degree of diaphragm injury and cytokines concentration in a preclinical ARDS model. Moderate ARDS was induced in pigs using oleic acid, followed by ventilation for 12 h post-injury with volume-control at 8 mL/kg, positive end-expiratory pressure (PEEP) 5 cmH2O, respiratory rate and [Formula: see text] set to achieve normal arterial blood gases. Two groups received TTDN: every second breath (MV + TTDN50%, n = 6) or every breath (MV + TTDN100%, n = 6). One group received ventilation only (MV, n = 6). Full-thickness diaphragm and quadricep muscle biopsies were taken at study end. Samples were fixed and stained with hematoxylin and eosin and a point-counting technique was applied to calculate abnormal muscle area fraction. Cytokine concentrations were measured in homogenized tissue using porcine-specific enzyme-linked immunosorbent assay (ELISA) and compared with serum samples. Percentage of abnormal diaphragm tissue was different between MV [8.1% (6.0-8.8)] versus MV + TTDN50% [3.4% (2.1-4.8)], P = 0.010 and MV versus MV + TTDN100% [3.1% (2.5-4.0)], P = 0.005. Percentage of abnormal quadriceps tissue was not different between groups. Cytokine concentration patterns in diaphragm samples were different between all groups (P < 0.001) and the interaction between TTDN application and resultant cytokine concentration pattern was significant (P = 0.025). TTDN, delivered in synchrony with mechanical ventilation, mitigated diaphragm injury, as evidenced by less abnormal tissue in the diaphragm samples, in pigs with oleic acid-induced ARDS and is an exciting tool for lung and diaphragm-protective ventilation.NEW & NOTEWORTHY This study adds to our understanding of applying transvenous diaphragm neurostimulation synchronously with mechanical ventilation by examining its effects on diaphragm muscle injury and cytokine concentration patterns in pigs with acute respiratory distress syndrome (ARDS). We observed that using this therapy for 12 h post lung injury mitigated ventilator-induced diaphragm injury and changed the pattern of cytokine concentration measured in diaphragm tissue. These findings suggest that transvenous diaphragm neurostimulation is an exciting tool for lung and diaphragm protective ventilation.

Development and validation of a model for predicting prolonged weaning from mechanical ventilation in patients with abdominal trauma

BACKGROUND

This study aimed to develop and validate a model to predict the risk of prolonged weaning from mechanical ventilation in patients with abdominal trauma.

METHODS

Patients with abdominal trauma were included and were divided into the training cohort and the validation cohort. The model was constructed using predictive factors identified by univariable and multivariable logistic regressions, and was validated by receiver operating characteristic curve, calibration curve, and decision curve analysis. Clinical outcomes were compared between model-stratified risk groups.

RESULTS

In total,190 patients were included, with 133 in the training cohort and 57 in the validation cohort. Six predictive factors, the Acute Physiology and Chronic Health Evaluation II score, Injury Severity Score, Glasgow coma scale, total bilirubin, skeletal muscle index, and abdominal fat index, were identified and were included in the model. The model predicting prolonged weaning owned a good discrimination, had an excellent calibration, and exhibited a favorable net benefit within a reasonable range of threshold probabilities. Significant differences were shown in prolonged weaning and clinical outcomes between the high-risk and low-risk groups (P < .05). Multivariable Cox regression analysis showed that patients in the high-risk group had greater risk of 28-day mortality (P < .05).

CONCLUSION

This study established a model to predict the risk of prolonged weaning from mechanical ventilation and clinical outcomes in patients with abdominal trauma. Skeletal muscle index was identified as one of independent risk factors of prolonged weaning. The findings offer valuable insights for respiratory management in patients with abdominal trauma.

A Multidimensional Approach to the Management of Patients in Prolonged Weaning from Mechanical Ventilation: The Concept of Treatable Traits - A Narrative Review

BACKGROUND

Established structured weaning approaches, which are effective for patients in simple and difficult weaning, are often not appropriate for patients undergoing prolonged weaning. Addressing the complexity of weaning failure requires personalized precision medicine. The therapeutic concept of treatable traits (TTs) has been proposed as a new paradigm for the management of chronic respiratory diseases. It is based on a multidimensional assessment of specific characteristics, which can be addressed by specific interventions that go beyond traditional diagnostic criteria. The concept is increasingly adopted for other complex diseases.

SUMMARY

This is a narrative review and an expert opinion on the development of a concept of TTs for patients undergoing prolonged weaning. The proposed TTs are based on a systematic review of risk factors for prolonged weaning, an analysis of claims data to assess risk factors within 96 h of IMV onset and data from the WEAN SAFE study. A multidisciplinary team identified clinically important TTs and determined appropriate interventions. The following TTs have been identified: airway disorders and complications associated with tracheostomy or intubation, such as airway obstruction, strictures or tracheomalacia, infectious aspects, anxiety, depression, delirium, post-traumatic stress disorder, anemia, pulmonary and cardio-renal disease. The multidimensional holistic approach also includes tailored sedation and pain management, nutritional therapy, early mobilization, and physiotherapy.

KEY MESSAGE

We propose a framework of relevant considerations for a multidimensional approach to the management of patients undergoing prolonged weaning that supports the regain of respiratory capacity, reduces the respiratory load, and thus could resolve the respiratory workload imbalance.

Weaning Failure in Elderly Patients: A Systematic Review and Meta-Analysis

Background/Objectives: Weaning failure in elderly patients undergoing mechanical ventilation presents a complex clinical challenge due to age-related physiological changes and comorbidities. Understanding the dynamics of this phenomenon through systematic analysis can provide valuable insights for clinical management. This meta-analysis aims to investigate the factors contributing to weaning failure in elderly patients and to assess the efficacy of different strategies in mitigating this challenge. Design: The design of this study is a systematic review and meta-analysis. Methods: A systematic search of electronic databases was conducted to identify relevant studies focusing on weaning failure in elderly patients. Studies reporting outcomes related to mechanical ventilation weaning failure were included. Data extraction, quality assessment, and statistical analysis were performed following established guidelines. Results: A total of 15 studies met the inclusion criteria and were included in the meta-analysis. The average age of participants throughout the studies was 66.24 ± 10.21 years. This suggests that the study population largely consisted of older adults and displayed a moderate range of ages centered around the mean. The rate of weaning failure across these studies was slightly above 31.56%, indicating a significant occurrence of this complication in the patient cohorts. The analysis revealed age-related physiological changes, such as decreased respiratory muscle strength and increased chest wall stiffness, as significant contributors to weaning failure in elderly patients. Comorbidities, including chronic pulmonary diseases and cardiovascular conditions, further exacerbated the challenge. Various interventions, including tailored weaning protocols and respiratory therapies, showed promising results in improving weaning outcomes in this population. Conclusions: Weaning failure in elderly patients undergoing mechanical ventilation is influenced by a combination of age-related physiological changes and comorbidities. Tailored interventions addressing these factors are essential for optimizing weaning success rates in this vulnerable population. Further research is warranted to refine the strategies and enhance outcomes in elderly patients requiring mechanical ventilation.

Predictive Value of Diaphragm and Lung Ultrasonography for Weaning Failure in Critically Ill Patients with Acute Respiratory Failure Due to COVID-19 Pneumonia

BACKGROUND

This study analyzed weaning characteristics and assessed the association of clinical and ultrasonographic indices-maximum inspiratory pressure (MIP), rapid shallow breathing index (RSBI), peak flow expiratory (PFE), diaphragm-thickening fraction (DTF), diaphragm thickness (DT), diaphragm excursion (DE), diaphragm-RSBI (D-RSBI), and lung ultrasound (LUS) patterns-with weaning failure.

METHODS

This retrospective cohort study included critically ill COVID-19 patients aged 18 and older who had been on invasive mechanical ventilation for at least 48 h and undergoing weaning. Exclusion criteria included absence of ultrasound assessments, neuromuscular diseases, and chronic cardio-respiratory dysfunction.

RESULTS

Among 61 patients, 44.3% experienced weaning failure, 27.9% failed the spontaneous breathing trial (SBT), 16.4% were re-intubated within 48 h, and 28% required tracheostomy. Weaning failure was associated with prolonged ventilation (29 vs. 7 days, p < 0.001), extended oxygen therapy, longer ICU stays, and higher ICU mortality. These patients had higher pressure support, lower oxygenation levels, a higher RSBI, and a lower MIP. While PEF, DTF, DE, and D-RSBI showed no significant differences, both right and left diaphragm thicknesses and the inspiratory thickness of the left diaphragm were reduced in failure cases. LUS scores were significantly higher before and after SBT in the failure group. Bivariate analysis identified RSBI [OR = 1.04 (95% CI = 1.01-1.07), p = 0.010], MIP [OR = 0.92 (95% CI = 0.86-0.99), p = 0.018], and LUS [OR = 1.15 (95% CI = 0.98-1.35), p = 0.025] as predictors of weaning failure; however, these associations were not confirmed in multivariate analysis.

CONCLUSIONS

Ultrasound provides supplementary information during weaning, but no definitive association between ultrasound indices and weaning failure was confirmed in this study.

Impact of sleep disturbances on outcomes in intensive care units

BACKGROUND

Sleep deprivation is common in intensive care units (ICUs) and may alter respiratory performance. Few studies have assessed the role of sleep disturbances on outcomes in critically ill patients.

OBJECTIVES

We hypothesized that sleep disturbances may be associated with poor outcomes in ICUs.

METHODS

Post-hoc analysis pooling three observational studies assessing sleep by complete polysomnography in 131 conscious and non-sedated patients included at different times of their ICU stay. Sleep was assessed early in a group of patients admitted for acute respiratory failure while breathing spontaneously (n = 34), or under mechanical ventilation in patients with weaning difficulties (n = 45), or immediately after extubation (n = 52). Patients admitted for acute respiratory failure who required intubation, those under mechanical ventilation who had prolonged weaning, and those who required reintubation after extubation were considered as having poor clinical outcomes. Durations of deep sleep, rapid eye movement (REM) sleep, and atypical sleep were compared according to the timing of polysomnography and the clinical outcomes.

RESULTS

Whereas deep sleep remained preserved in patients admitted for acute respiratory failure, it was markedly reduced under mechanical ventilation and after extubation (p < 0.01). Atypical sleep was significantly more frequent in patients under mechanical ventilation than in those breathing spontaneously (p < 0.01). REM sleep was uncommon at any time of their ICU stay. Patients with complete disappearance of REM sleep (50% of patients) were more likely to have poor clinical outcomes than those with persistent REM sleep (24% vs. 9%, p = 0.03).

CONCLUSION

Complete disappearance of REM sleep was significantly associated with poor clinical outcomes in critically ill patients.

Differences between women and men in prolonged weaning

BACKGROUND

In recent years, the importance of sex as a factor influencing medical care has received increasing attention in the field of intensive care medicine. The objective of this study was to examine the influence of sex in prolonged weaning.

METHODS

A retrospective analysis of patients undergoing prolonged weaning at Thoraxklinik, University Hospital Heidelberg between 12/08 and 12/23 was conducted. Patients with neuromuscular diseases were excluded from the analyses. The risk factors for weaning failure in men and women were identified through stepwise cox-regression analyses.

RESULTS

A total of 785 patients were included, of whom 313 (39.9%) were women. 77.9% of the women and 75.4% of the men were successfully weaned from invasive ventilation. In group comparisons and multivariable analyses, sex was not found to be a risk factor for weaning failure. Cox regression analyses were performed separately for both sexes on the outcome of weaning failure, adjusting for relevant covariates. The results indicated that age ≥ 65 years (HR 2.38, p < 0.001) and the duration of IMV before transfer to the weaning centre (HR 1.01/day, p < 0.001) were independent risk factors in men. In women, however, the duration of IMV before transfer (HR 1.01, p < 0.001), previous non-invasive ventilation (HR 2.9, p 0.005), the presence of critical illness polyneuropathy (HR 1.82; p = 0.040) and delirium (HR 2.50, p = 0.017) were identified as relevant risk factors. In contrast delirium was associated with a favourable weaning outcome in men (HR 0.38, p = 0.020) and nosocomial pneumonia as a reason for prolonged weaning in women (HR 0.43; p = 0.032).

CONCLUSION

The analyses indicate that there are sex-based differences in the risk factors associated with weaning failure. Further studies, ideally prospective, should confirm these findings to assess whether sex is a factor that should be taken into account to improve weaning outcomes.

The ratio of parasternal intercostal muscle-thickening fraction-to-diaphragm thickening fraction for predicting weaning failure

BACKGROUND

Diaphragm dysfunction is associated with weaning outcomes in mechanical ventilation patients, in the case of diaphragm dysfunction, the accessory respiratory muscles would be recruited. The main purpose of this study is to explore the performance of parasternal intercostal muscle thickening fraction in relation to diaphragmatic thickening fraction ratio (TFic1/TFdi2) for predicting weaning outcomes, and compare its accuracy with D-RSBI in predicting weaning failure.

MATERIALS AND METHODS

We prospectively enrolled consecutive patients from 7/2022-5/2023. We measured TFic, TFdi, and diaphragmatic excursion (DE3) by ultrasound and calculated the TFic/TFdi ratio and diaphragmatic rapid shallow breathing index (D-RSBI4). Receiver-operator characteristic (ROC5) curves evaluated the accuracy of the TFic/TFdi ratio and D-RSBI in predicting weaning failure.

RESULTS

161 were included in the final analysis, 114 patients (70.8%) were successfully weaned from mechanical ventilation. The TFic/TFdi ratio (AUROC = 0.887 (95% CI: 0.821-0.953)) was superior to the D-RSBI (AUROC = 0.875 (95% CI: 0.807-0.944)) for predicting weaning failure.

CONCLUSIONS

The TFic/TFdi ratio predicted weaning failure with high accuracy and outperformed the D-RSBI.

Prolonged weaning from mechanical ventilation: who, what, when and how?

Weaning from invasive mechanical ventilation is an important part of the management of respiratory failure patients. Patients can be classified into those who wean on the first attempt (simple weaning), those who require up to three attempts (difficult weaning) and those who require more than three attempts (prolonged weaning). The process of weaning includes adequately treating the underlying cause of respiratory failure, assessing the readiness to wean, evaluating the response to a reduction in ventilatory support, and eventually liberation from mechanical ventilation and extubation or decannulation. Post-extubation respiratory failure is a contributor to poorer outcomes. Identifying and addressing modifiable risk factors for post-extubation respiratory failure is important; noninvasive ventilation and high-flow nasal cannulae may be useful bridging aids after extubation. Factors to consider in the pathophysiology of prolonged mechanical ventilation include increased respiratory muscle load, reduced respiratory muscle capacity and reduced respiratory drive. Management of these patients involves a multidisciplinary team, to first identify the cause of failed weaning attempts, and subsequently optimise the patient's physiology to improve the likelihood of being successfully weaned from invasive mechanical ventilation.

Time course of electrical activity of the diaphragm (EAdi) in the peri extubation period and its role as predictor of extubation failure in difficult to wean patients

INTRODUCTION

Weaning patients from mechanical ventilation is crucial in the management of acute respiratory failure (ARF). Spontaneous breathing trials (SBT) are used to assess readiness for extubation, but extubation failure remains a challenge. Diaphragmatic function, measured by electrical activity of the diaphragm (EAdi), may provide insights into weaning outcomes.

MATERIALS AND METHODS

This prospective, observational study included difficult-to-wean patients undergoing invasive mechanical ventilation. EAdi was recorded before, during, and after extubation. Patients were categorized into extubation success and failure groups based on reintubation within 48 h. Statistical analysis assessed EAdi patterns and predictive value.

RESULTS

Thirty-one patients were analyzed, with six experiencing extubation failure. Overall, EAdi increased significantly between the phases before the SBT, the SBT and post-extubation period, up to 24 h (p < 0.001). EAdi values were higher in the extubation failure group during SBT (p = 0.01). An EAdi > 30 μV during SBT predicted extubation failure with 92% sensitivity and 67% specificity. Multivariable analysis confirmed EAdi as an independent predictor of extubation failure.

CONCLUSIONS

In difficult-to-wean patients, EAdi increases significantly between the phases before the SBT, the SBT and post-extubation period and is significantly higher in patients experiencing extubation failure. An EAdi > 30 μV during SBT may enhance extubation failure prediction compared to conventional parameters. Advanced monitoring of diaphragmatic function could improve weaning outcomes in critical care settings.

Machine learning-based risk prediction model construction of difficult weaning in ICU patients with mechanical ventilation

In intensive care unit (ICU) patients undergoing mechanical ventilation (MV), the occurrence of difficult weaning contributes to increased ventilator-related complications, prolonged hospitalization duration, and a significant rise in healthcare costs. Therefore, early identification of influencing factors and prediction of patients at risk of difficult weaning can facilitate early intervention and preventive measures. This study aimed to strengthen airway management for ICU patients by constructing a risk prediction model with comprehensive and individualized offline programs based on machine learning techniques. This study involved the collection of data from 487 patients undergoing MV in the ICU, with a total of 36 variables recorded. The dataset was divided into a training set (70% of the data) and a test set (30% of the data). Five machine learning models, namely logistic regression, random forest, support vector machine, light gradient boosting machine, and extreme gradient boosting, were compared to predict the risk of difficult weaning in ICU patients with MV. Significant influencing factors were identified based on the results of these models, and a risk prediction model for ICU patients with MV was established. When evaluating the models using AUC (Area under the Curve of ROC) and Accuracy as performance metrics, the Random Forest algorithm exhibited the best performance among the five machine learning algorithms. The area under the operating characteristic curve for the subjects was 0.805, with an accuracy of 0.748, recall (0.888), specificity (0.767) and F1 score (0.825). This study successfully developed a risk prediction model for ICU patients with MV using a machine learning algorithm. The Random Forest algorithm demonstrated the highest prediction performance. These findings can assist clinicians in accurately assessing the risk of difficult weaning in patients and formulating effective individualized treatment plans. Ultimately, this can help reduce the risk of difficult weaning and improve the quality of life for patients.

Position Statement of ISCCM Committee on Weaning from Mechanical Ventilator

BACKGROUND AND PURPOSE

Weaning from a mechanical ventilator is a milestone in the recovery of seriously ill patients in Intensive care. Failure to wean and re-intubation adversely affects the outcome. The method of mechanical ventilation (MV) varies between different ICUs and so does the practice of weaning. Therefore, updated guidelines based on contemporary literature are designed to guide intensivists in modern ICUs. This is the first ISCCM Consensus Statement on weaning complied by a committee on weaning. The recommendations are intended to be used by all the members of the ICU (Intensivists, Registrars, Nurses, and Respiratory Therapists).

METHODS

A Committee on weaning from MV, formed by the Indian Society of Critical Care Medicine (ISCCM) has formulated this statement on weaning from mechanical ventilators in intensive care units (ICUs) after a review of the literature. Literature was first circulated among expert committee members and allotted sections to each member. Sections of the statement written by sectional authors were peer-reviewed on multiple occasions through virtual meetings. After the final manuscript is accepted by all the committee members, it is submitted for peer review by central guideline committee of ISCCM. Once approved it has passed through review by the Editorial Board of IJCCM before it is published here as "ISCCM consensus statement on weaning from mechanical ventilator". As per the standard accepted for all its guidelines of ISCCM, we followed the modified grading of recommendations assessment, development and evaluation (GRADE) system to classify the quality of evidence and strength of recommendation. Cost-benefit, risk-benefit analysis, and feasibility of implementation in Indian ICUs are considered by the committee along with the strength of evidence. Type of ventilators and their modes, ICU staffing pattern, availability of critical care nurses, Respiratory therapists, and day vs night time staffing are aspects considered while recommending for or against any aspect of weaning.

RESULT

This document makes recommendation on various aspects of weaning, namely, definition, timing, weaning criteria, method of weaning, diagnosis of failure to wean, defining difficult to wean, Use of NIV, HFOV as adjunct to weaning, role of tracheostomy in weaning, weaning in of long term ventilated patients, role of physiotherapy, mobilization in weaning, Role of nutrition in weaning, role of diaphragmatic ultrasound in weaning prediction etc. Out of 42 questions addressed; the committee provided 39 recommendations and refrained from 3 questions. Of these 39; 32 are based on evidence and 7 are based on expert opinion of the committee members. It provides 27 strong recommendations and 12 weak recommendations (suggestions).

CONCLUSION

This guideline gives extensive review on weaning from mechanical ventilator and provides various recommendations on weaning from mechanical ventilator. Though all efforts are made to make is as updated as possible one needs to review any guideline periodically to keep it in line with upcoming concepts and standards.

HOW TO CITE THIS ARTICLE

Clerk AM, Shah RJ, Kothari J, Sodhi K, Vadi S, Bhattacharya PK, et al. Position Statement of ISCCM Committee on Weaning from Mechanical Ventilator. Indian J Crit Care Med 2024;28(S2):S233-S248.

Tissue Doppler imaging of the diaphragm and outcome of weaning from mechanical ventilation

Purpose

This study aimed to employ tissue Doppler imaging to monitor diaphragmatic peak velocity and acceleration during contraction and relaxation in mechanically ventilated patients, with the objective of assessing the potential utility of this technique in predicting weaning outcomes.

Methods

A total of 89 adult subjects were recruited in this study. After 30 min of spontaneous breathing trial, the diaphragm motion parameters, including peak contraction velocity, peak relaxation velocity, contraction acceleration and relaxation acceleration, were measured in real time using tissue Doppler imaging. According to the results of weaning, the patients were divided into successful weaning group and failed weaning group. The differences of diaphragmatic tissue Doppler imaging monitoring indicators between the two groups were analysed, and the receiver operating characteristic curve was drawn to analyse the value of each ultrasound parameter in predicting weaning.

Results

In the successful weaning group, there were 61 subjects, while in the failed weaning group, there were 28 subjects. The peak contraction velocity, peak relaxation velocity, contraction acceleration and relaxation acceleration of the diaphragm were significantly higher in the failed weaning group compared to the successful weaning group (P < 0.05). The area under the curve of diaphragmatic peak contraction velocity, peak relaxation velocity, diaphragmatic contraction acceleration and diaphragmatic relaxation acceleration were 0.81 (0.72-0.91), 0.85 (0.77-0.93), 0.74 (0.63-0.86) and 0.86 (0.78-0.94), respectively.

Conclusions

The diaphragm ultrasonic tissue Doppler imaging variables can serve as predictive indicators for weaning mechanical ventilation in patients, thus providing an effective tool to assist critical care physicians in determining the optimal timing for weaning mechanical ventilation.

Super-relaxed myosins contribute to respiratory muscle hibernation in mechanically ventilated patients

Patients receiving mechanical ventilation in the intensive care unit (ICU) frequently develop contractile weakness of the diaphragm. Consequently, they may experience difficulty weaning from mechanical ventilation, which increases mortality and poses a high economic burden. Because of a lack of knowledge regarding the molecular changes in the diaphragm, no treatment is currently available to improve diaphragm contractility. We compared diaphragm biopsies from ventilated ICU patients (N = 54) to those of non-ICU patients undergoing thoracic surgery (N = 27). By integrating data from myofiber force measurements, x-ray diffraction experiments, and biochemical assays with clinical data, we found that in myofibers isolated from the diaphragm of ventilated ICU patients, myosin is trapped in an energy-sparing, super-relaxed state, which impairs the binding of myosin to actin during diaphragm contraction. Studies on quadriceps biopsies of ICU patients and on the diaphragm of previously healthy mechanically ventilated rats suggested that the super-relaxed myosins are specific to the diaphragm and not a result of critical illness. Exposing slow- and fast-twitch myofibers isolated from the diaphragm biopsies to small-molecule compounds activating troponin restored contractile force in vitro. These findings support the continued development of drugs that target sarcomere proteins to increase the calcium sensitivity of myofibers for the treatment of ICU-acquired diaphragm weakness.