Effect of aggressive vs conservative screening and confirmatory test on time to extubation among patients at low or intermediate risk: a randomized clinical trial

Physiological comparison of noninvasive ventilation and high-flow nasal oxygen on inspiratory efforts and tidal volumes after extubation: a randomized crossover trial

BACKGROUND

Extubation failure leading to reintubation is associated with high mortality. In patients at high-risk of extubation failure, clinical practice guidelines recommend prophylactic non-invasive ventilation (NIV) over high-flow nasal oxygen (HFNO) immediately after extubation. However, the physiological effects supporting the beneficial effect of NIV have been poorly explored. We hypothesized that NIV may reduce patient inspiratory efforts to a greater extent than HFNO after extubation.

METHODS

In a prospective physiological study, patients at high-risk of extubation failure (> 65 years old or underlying cardiac or respiratory disease) were included to receive after planned extubation prophylactic NIV and HFNO in a randomized crossover order, followed by standard oxygen. Inspiratory efforts were assessed by calculation of the simplified esophageal pressure-time-product per minute (sPTPes in cmH2O s/min). Tidal volumes, distribution and homogeneity of ventilation were estimated using electrical impedance tomography.

RESULTS

Twenty patients were retained in the analysis. Inspiratory efforts were lower with NIV than with HFNO (sPTPes 196 cm H2O s/min [116-234] vs. 220 [178-327], p < 0.001) whereas tidal volumes were larger with NIV than with HFNO (8.4 mL/kg of predicted body weight [6.7-9.9] vs. 6.9 [5.3-8.6], p = 0.005). There was a non-significant increase in dorsal region ventilation under NIV compared to HFNO.

CONCLUSIONS

In patients at high-risk of extubation failure, prophylactic NIV significantly decreased inspiratory efforts with increased tidal volumes compared to HFNO. The clinical benefits of NIV to prevent reintubation in patients at high-risk may be mediated by these physiological effects. Trial registration Clinicaltrials.gov: ID NCT04036175), retrospectively registered 17 June 2019.

Spontaneous breathing trials: how and for how long?

PURPOSE OF REVIEW

Guidelines recommend systematic performance of a spontaneous breathing trial (SBT) before extubation in ICUs, the objective being to reduce the risk of reintubation. In theory, a more challenging SBT performed with a T-piece may further reduce the risk of reintubation, whereas a less challenging SBT performed with pressure-support ventilation (PSV) may hasten extubation.

RECENT FINDINGS

Recent findings show that a more challenging SBT with a T-piece or for a prolonged duration do not help to reduce the risk of reintubation. In contrast, a less challenging SBT with PSV is easier to pass than a T-piece, and may hasten extubation without increased risk of reintubation. Although SBT with PSV and additional positive end-expiratory pressure is indeed a less challenging SBT, further studies are needed to generalize such an easy trial in daily practice. Earlier screening for a first SBT may also decrease time to extubation without increased risk of reintubation. Lastly, reconnection to the ventilator for a short period after successful SBT facilitates recovery from the SBT-induced alveolar derecruitment.

SUMMARY

Several recent clinical trials have improved assessment of the most adequate way to perform SBT before extubation.

How to prevent postextubation respiratory failure

PURPOSE OF REVIEW

Postextubation respiratory support treatment approaches, indications, and subgroups of patients with different responses to those therapies are rapidly changing. Planning optimal therapy in terms of choosing devices, timing of application and selecting settings with the goal of minimizing extubation failure is becoming a challenge. This review aims to analyze all the available evidence from a clinical point of view, trying to facilitate decision making at the bedside.

RECENT FINDINGS

There is evidence for high flow nasal cannula support in patients at low risk of extubation failure. Noninvasive ventilation based strategies should be prioritized in patients at very high risk, who are obese or are hypercapnic at the end of a spontaneous breathing trial. Patients not included in the previous groups merit a tailored decision based on more variables.Optimizing the timing of therapy can include facilitation of extubation by transitioning to noninvasive respiratory support or prolonging a planned preventive therapy according to clinical condition.

SUMMARY

Planning postextubatin respiratory support must consider the risk for failing and the presence of some clinical conditions favoring noninvasive ventilation.Extubation can be safely accelerated by modifying screening criteria and spontaneous breathing trial settings, but there is room to increase the role of postextubation noninvasive respiratory support for this indication, always keeping in mind the dangers of delaying a needed intubation.

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.

Association Between Spontaneous Breathing Trial Methods and Reintubation in Adult Critically Ill Patients: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Reintubation is associated with higher risk of mortality. There is no clear evidence on the best spontaneous breathing trial (SBT) method to reduce the risk of reintubation.

RESEARCH QUESTION

Are different methods of conducting SBTs in critically ill patients associated with different risk of reintubation compared with T-tube?

STUDY DESIGN AND METHODS

We conducted a systematic review and Bayesian network meta-analysis of randomized controlled trials investigating the effects of different SBT methods on reintubation. We surveyed PubMed, MEDLINE, CINAHL, and Cochrane Central Register of Controlled Trials databases from inception to January 26, 2024. The surface under the cumulative ranking curve (SUCRA) was used to determine the likelihood that an intervention was ranked as the best. Pairwise comparisons were also investigated by frequentist meta-analysis. Certainty of the evidence was assessed according to the Grading of Recommendations, Assessment, Development, and Evaluations approach.

RESULTS

A total of 22 randomized controlled trials were included, for a total of 6,196 patients. The network included nine nodes, with 13 direct pairwise comparisons. About 71% of the patients were allocated to T-tube and pressure support ventilation without positive end-expiratory pressure, with 2,135 and 2,101 patients, respectively. The only intervention with a significantly lower risk of reintubation compared with T-tube was high-flow oxygen (HFO) (risk ratio, 0.23; 95% credibility interval, 0.09-0.51; moderate quality evidence). HFO was associated with the highest probability of being the best intervention for reducing the risk of reintubation (81.86%; SUCRA, 96.42), followed by CPAP (11.8%; SUCRA, 76.75).

INTERPRETATION

In this study, HFO SBT was associated with a lower risk of reintubation compared with other SBT methods. The results of our analysis should be considered with caution due to the low number of studies that investigated HFO SBTs and potential clinical heterogeneity related to cointerventions. Further trials should be performed to confirm the results on larger cohorts of patients and to assess specific subgroups.

TRIAL REGISTRATION

PROSPERO; No.: CRD42023449264; URL: https://www.crd.york.ac.uk/prospero/.

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.

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.

Noninvasive ventilation on reintubation in patients with obesity and hypoxemic respiratory failure following abdominal surgery: a post hoc analysis of a randomized clinical trial

PURPOSE

Although noninvasive ventilation (NIV) may reduce reintubation in patients with acute hypoxemic respiratory failure following abdominal surgery, this strategy has not been specifically assessed in patients with obesity.

METHODS

We conducted a post hoc analysis of a multicenter randomized controlled trial comparing NIV delivered via facial mask to standard oxygen therapy among patients with obesity and acute hypoxemic respiratory failure within 7 days after abdominal surgery. The primary outcome was reintubation within 7 days. Secondary outcomes were invasive ventilation-free days at day 30, intensive care unit (ICU)-acquired pneumonia and 30-day survival.

RESULTS

Among 293 patients with hypoxemic respiratory failure following abdominal surgery, 76 (26%) patients had obesity and were included in the intention-to-treat analysis. Reintubation rate was significantly lower with NIV (13/42, 31%) than with standard oxygen therapy (19/34, 56%) within 7 days (absolute difference: - 25%, 95% confidence interval (CI) - 49 to - 1%, p = 0.03). NIV was associated with significantly more invasive ventilation-free days compared with standard oxygen therapy (27.1 ± 8.6 vs 22.7 ± 11.1 days; p = 0.02), while fewer patients developed ICU-acquired pneumonia (1/42, 2% vs 6/34, 18%; p = 0.04). The 30-day survival was 98% in the NIV group (41/42) versus 85% in the standard oxygen therapy (p = 0.08). In patients with body mass index (BMI) < 30 kg/m2, no significant difference was observed between NIV (36/105, 34%) and standard oxygen therapy (47/109, 43%, p = 0.03). An interaction test showed no statistically significant difference between the two subsets (BMI ≥ 30 kg/m2 and BMI < 30 kg/m2).

CONCLUSIONS

Among patients with obesity and hypoxemic respiratory failure following abdominal surgery, use of NIV compared with standard oxygen therapy reduced the risk of reintubation within 7 days, contrary to patients without obesity. However, no interaction was found according to the presence of obesity or not, suggesting either a lack of power to conclude in the non-obese subgroup despite existing differences, or that the statistical difference found in the overall sample was driven by a large effect in the obese subsets.