Predictors of successful weaning from prolonged mechanical ventilation in Taiwan

Enhancing healthcare AI stability with edge computing and machine learning for extubation prediction

The advancement of the Internet of Medical Things (IoMT) has revolutionized data acquisition and processing in critical care settings. Given the pivotal role of ventilators, accurately predicting extubation outcomes is essential to optimize patient care. This study presents an edge computing-based framework that incorporates machine learning algorithms to predict ventilator extubation success using real-time data collected directly from ventilators. The system was deployed on edge devices to enable on-site inference with minimal latency. Among the evaluated models, Random Forest and XGBoost, the latter demonstrated superior predictive performance under both holdout and tenfold cross-validation schemes. Notably, the edge-based architecture reduced server data transmissions by 83.33%, while improving system stability, resilience, and sustainability. This paper details the model evaluation and demonstrates the feasibility and efficiency of edge intelligence in ventilator weaning decision support.

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.

Persistent inflammation and lymphopenia and weaning outcomes of patients with prolonged mechanical ventilation

BACKGROUND

Weaning outcomes of patients receiving mechanical ventilation (MV) are affected by multiple factors. A clinical feature of critically ill patients is the presence of lymphopenia, however the clinical significance of lymphopenia in patients receiving prolonged MV remains unclear.

METHODS

We enrolled patients who received at least 21 consecutive days of MV in a medical center in Taiwan between 2007 and 2016. Patients with and without lymphopenia (mean count <1000/μL) were compared after propensity score matching.

RESULTS

Of the 3460 patients included in the analysis, 1625 (47.0%) were liberated from MV within 100 days. Lymphopenia and severe lymphopenia (mean count <500/μL) during the first 21 days of MV were common (52.9% and 14.5%, respectively), and restricted cubic spline analysis showed a significant reduction in weaning success when the lymphocyte count dropped below 1000/μL. After propensity score matching, the patients with lymphopenia during the third week had a lower rate of weaning success within 100 days (p = 0.005) and a higher in-hospital mortality rate (p = 0.001) than those without lymphopenia. The lymphopenia group also had significantly reduced platelet (p < 0.001) and albumin (p < 0.001) levels.

CONCLUSIONS

Our findings suggest that lymphopenia during the first 3 weeks may be a marker of poor weaning outcomes in patients with prolonged MV.

Development of a core predictor set of weaning in critically ill patients: a Delphi-based study protocol

INTRODUCTION

Prolonged mechanical ventilation in intensive care units (ICUs) leads to increased morbidity, higher mortality rates, and elevated healthcare costs. Predicting successful weaning from mechanical ventilation with accuracy is essential for optimizing resource use and improving patient outcomes. The International Classification of Functioning, Disability and Health (ICF) framework offers a holistic perspective on health conditions and can be adapted to identify key predictors of weaning readiness. This study aims to develop a Delphi-based core predictor set for weaning in critically ill patients, utilizing the ICF model.

METHODS AND ANALYSIS

The core predictor set development comprises three steps: (1) Literature review and expert consultation to gather weaning predictors, (2) Predictor alignment with ICF categories per established rules, and (3) Three-round Delphi survey with a multidisciplinary team. A systematic review across major databases will be conducted to identify predictors related to weaning predictors in critically ill adults from cohort studies, trials, and reviews. Predictors will then be categorized within ICF domains. A multidisciplinary expert panel will evaluate the relevance of each predictor using a 9-point Likert scale to achieve consensus.

DISCUSSION

This study will contribute to the development of a standardized, evidence-based predictor set for weaning readiness in critically ill patients. Using the ICF framework, this study aims to encompass the complex factors that influence weaning, thereby enabling personalized care plans and improving weaning outcomes. The Delphi methodology guarantees a thorough, iterative process for building consensus by integrating diverse clinical perspectives.

CONCLUSION

The proposed Delphi-based study protocol aims to establish a core set of predictors for weaning in the ICU setting, guided by the ICF model. Successful implementation of this predictor set could enhance decision-making around weaning trials, reduce unnecessary ventilation days, and ultimately improve patient outcomes and healthcare efficiency. Future validation and implementation studies will be essential to confirm the utility and generalizability of this predictor set in clinical practice.

Outcomes of different pulmonary rehabilitation protocols in patients under mechanical ventilation with difficult weaning: a retrospective cohort study

BACKGROUND

The endeavor of liberating patients from ventilator dependence within respiratory care centers (RCCs) poses considerable challenges. Multiple factors contribute to this process, yet establishing an effective regimen for pulmonary rehabilitation (PR) remains uncertain. This retrospective study aimed to evaluate existing rehabilitation protocols, ascertain associations between clinical factors and patient outcomes, and explore the influence of these protocols on the outcomes of the patients to shape suitable rehabilitation programs.

METHODS

Conducted at a medical center in northern Taiwan, the retrospective study examined 320 newly admitted RCC patients between January 1, 2015, and December 31, 2017. Each patient received a tailored PR protocol, following which researchers evaluated weaning rates, RCC survival, and 3-month survival as outcome variables. Analyses scrutinized differences in baseline characteristics and prognoses among three PR protocols: protocol 1 (routine care), protocol 2 (routine care plus breathing training), and protocol 3 (routine care plus breathing and limb muscle training).

RESULTS

Among the patients, 28.75% followed protocol 1, 59.37% protocol 2, and 11.88% protocol 3. Variances in age, body-mass index, pneumonia diagnosis, do-not-resuscitate orders, Glasgow Coma Scale scores (≤ 14), and Acute Physiology and Chronic Health Evaluation II (APACHE) scores were notable across these protocols. Age, APACHE scores, and abnormal blood urea nitrogen levels (> 20 mg/dL) significantly correlated with outcomes-such as weaning, RCC survival, and 3-month survival. Elevated mean hemoglobin levels linked to increased weaning rates (p = 0.0065) and 3-month survival (p = 0.0102). Four adjusted models clarified the impact of rehabilitation protocols. Notably, the PR protocol 3 group exhibited significantly higher 3-month survival rates compared to protocol 1, with odds ratios (ORs) ranging from 3.87 to 3.97 across models. This association persisted when comparing with protocol 2, with ORs between 3.92 and 4.22.

CONCLUSION

Our study showed that distinct PR protocols significantly affected the outcomes of ventilator-dependent patients within RCCs. The study underlines the importance of tailored rehabilitation programs and identifies key clinical factors influencing patient outcomes. Recommendations advocate prospective studies with larger cohorts to comprehensively assess PR effects on RCC patients.

A historical cohort study on predictors for successful weaning from prolonged mechanical ventilation and up to 3-year survival follow-up in a rehabilitation center

BACKGROUND

We followed prolonged mechanically ventilated (PMV) patients for weaning attempts and explored factors associated with successful weaning and long-term survival.

METHODS

This historical cohort study included all adult PMV patients admitted to a single rehabilitation hospital during 2015-2018 and followed for survival according to weaning success up to 3 years or the end of 2021.

RESULTS

The study included 223 PMV patients. Of them, 124 (55.6 %) underwent weaning attempts, with 69 (55.6 %) successfully weaned, 55 (44.4 %) unsuccessfully weaned, and 99 patients with no weaning attempts. The mean age was 67 ± 20 years, with 39 % female patients. Age, sex distributions and albumin levels at admission were not significantly different among the groups. The successful weaning group had a 6 % higher proportion of conscious patients than the failed weaning group (55 % vs. 49 %, respectively, p = 0.45). Patients successfully weaned were less frequently treated with antibiotics for 5 days or more than those unsuccessfully weaned (74 % vs 80 %, respectively, p = 0.07). They also had a lower proportion of time from intubation to tracheostomy greater than 14 days (45 % vs 66 %, p = 0.02). The age, sex, antibiotic treatment, time to tracheostomy exceeding 14 days and time from admission to first weaning attempt adjusted one-year mortality risk of successful vs. failed weaning was somewhat lower, HR = 0.75, 95%CI: 0.33-1.60, p = 0.45, with the same trend by the end of 3 years, HR = 0.77, 95%CI: 0.42-1.39, p = 0.38.

CONCLUSION

Successful weaning from PMV may be associated with better survival and allows chronically ventilated patients to become independent on a ventilator. A larger study is needed to further validate our findings.

Predicting Successful Weaning from Mechanical Ventilation by Reduction in Positive End-expiratory Pressure Level Using Machine Learning

Weaning patients from mechanical ventilation (MV) is a critical and resource intensive process in the Intensive Care Unit (ICU) that impacts patient outcomes and healthcare expenses. Weaning methods vary widely among providers. Prolonged MV is associated with adverse events and higher healthcare expenses. Predicting weaning readiness is a non-trivial process in which the positive end-expiratory pressure (PEEP), a crucial component of MV, has potential to be indicative but has not yet been used as the target. We aimed to predict successful weaning from mechanical ventilation by targeting changes in the PEEP-level using a supervised machine learning model. This retrospective study included 12,153 mechanically ventilated patients from Medical Information Mart for Intensive Care (MIMIC-IV) and eICU collaborative research database (eICU-CRD). Two machine learning models (Extreme Gradient Boosting and Logistic Regression) were developed using a continuous PEEP reduction as target. The data is splitted into 80% as training set and 20% as test set. The model's predictive performance was reported using 95% confidence interval (CI), based on evaluation metrics such as area under the receiver operating characteristic (AUROC), area under the precision-recall curve (AUPRC), F1-Score, Recall, positive predictive value (PPV), and negative predictive value (NPV). The model's descriptive performance was reported as the variable ranking using SHAP (SHapley Additive exPlanations) algorithm. The best model achieved an AUROC of 0.84 (95% CI 0.83-0.85) and an AUPRC of 0.69 (95% CI 0.67-0.70) in predicting successful weaning based on the PEEP reduction. The model demonstrated a Recall of 0.85 (95% CI 0.84-0.86), F1-score of 0.86 (95% CI 0.85-0.87), PPV of 0.87 (95% CI 0.86-0.88), and NPV of 0.64 (95% CI 0.63-0.66). Most of the variables that SHAP algorithm ranked to be important correspond with clinical intuition, such as duration of MV, oxygen saturation (SaO2), PEEP, and Glasgow Coma Score (GCS) components. This study demonstrates the potential application of machine learning in predicting successful weaning from MV based on continuous PEEP reduction. The model's high PPV and moderate NPV suggest that it could be a useful tool to assist clinicians in making decisions regarding ventilator management.

Monitoring the performance of a dedicated weaning unit using risk-adjusted control charts for the weaning rate in prolonged mechanical ventilation

BACKGROUND

Weaning rate is an important quality indicator of care for patients with prolonged mechanical ventilation (PMV). However, diverse clinical characteristics often affect the measured rate. A risk-adjusted control chart may be beneficial for assessing the quality of care.

METHODS

We analyzed patients with PMV who were discharged between 2018 and 2020 from a dedicated weaning unit at a medical center. We generated a formula to estimate monthly weaning rates using multivariate logistic regression for the clinical, laboratory, and physiologic characteristics upon weaning unit admission in the first two years (Phase I). We then applied both multiplicative and additive models for adjusted p-charts, displayed in both non-segmented and segmented formats, to assess whether special cause variation existed.

RESULTS

A total of 737 patients were analyzed, including 503 in Phase I and 234 in Phase II, with average weaning rates of 59.4% and 60.3%, respectively. The p-chart of crude weaning rates did not show special cause variation. Ten variables from the regression analysis were selected for the formula to predict individual weaning probability and generate estimated weaning rates in Phases I and II. For risk-adjusted p-charts, both multiplicative and additive models showed similar findings and no special cause variation.

CONCLUSION

Risk-adjusted control charts generated using a combination of multivariate logistic regression and control chart-adjustment models may provide a feasible method to assess the quality of care in the setting of PMV with standard care protocols.

Application of improved Glasgow coma scale score as switching point for sequential invasive-noninvasive mechanical ventilation on chronic obstructive pulmonary disease (COPD) with respiratory failure

BACKGROUND

To compare the efficacy and feasibility of using a modified Glasgow coma scale (GCS) score of 13 or 15 as the criterion for switching chronic obstructive pulmonary disease (COPD) patients with respiratory failure to sequential invasive-noninvasive ventilation.

METHODS

COPD patients with respiratory failure who had undergone endotracheal intubation and invasive mechanical ventilation (IMV) between June 2017 and June 2020 at 4 different hospitals in China were included. A total of 296 patients were randomly divided into 2 groups. In group A, the patients were extubated and immediately placed on noninvasive ventilation (NIV) when the modified GCS score reached 13. In group B, the same was done when the modified GCS score reached 15.

RESULTS

No significant differences in the mean blood pressure, oxygenation index, arterial partial pressure of oxygen, and arterial partial pressure of carbon dioxide were seen between groups A and B before extubation and 3 hours after NIV. The re-intubation times were also similar in the 2 groups. Compared to group B, the length of hospital stay, incidence of ventilator associated pneumonia, and time of invasive ventilation were all significantly lower in group A (P = .041, .001, <.001).

CONCLUSION

Using a modified GCS score of 13 as the criterion for switching from IMV to NIV can significantly reduce the duration of IMV, length of hospital stay, and incidence of ventilator associated pneumonia in COPD patients with respiratory failure.

Predictive Factors of Extubation Failure in COVID-19 Mechanically Ventilated Patients

Purpose: We investigated whether COVID-19 patients on mechanical ventilation (MV) had a different extubation outcome compared to non-COVID-19 patients while identifying predictive factors of extubation failure in the former. Methods: A retrospective, single-center, and observational study was done on 216 COVID-19 patients admitted to an intensive care unit (ICU) between March 2020 and March 2021, aged ≥ 18 years, in use of invasive MV for more than 24 h, which progressed to weaning. The primary outcome that was evaluated was extubation failure during ICU stay. A statistical analysis was performed to evaluate the association of patient characteristics with extubation outcome, and a Poisson regression model determined the predictive value. Results: Seventy-seven patients were extubated; the mean age was 57.2 years, 52.5% were male, and their mean APACHE II score at admission was 17.8. On average, MV duration until extubation was 8.7 ± 3.7 days, with 14.9 ± 10.1 days of ICU stay and 24.6 ± 14.0 days with COVID-19 symptoms. The rate of extubation failure (ie, the patient had to be reintubated during their ICU stay) was 22.1% (n = 17), while extubation was successful in 77.9% (n = 60) of cases. Failure was observed in only 7.8% of cases when evaluated 48 hours after extubation. The mean reintubation time was 4.28 days. After adjusting the analysis for age, sex, during of symptoms, days under MV, dialysis, and PaO2/FiO2 ratio, some parameters independently predicted extubation failure: age ≥ 66 years (APR = 5.12 [1.35-19.46]; p = 0.016), ≥ 31 days of symptoms (APR = 5.45 [0.48-62.19]; p = 0.016), and need for dialysis (APR = 5.10 [2.00-13.00]; p = 0.001), while a PaO2/FiO2 ratio >300 decreased the probability of extubation failure (APR = 0.14 [0.04-0.55]; p = 0.005). The presence of three predictors (ie, age ≥ 66 years, time of symptoms ≥ 31 days, need of dialysis, and PaO2/FiO2 ratio < 200) increased the risk of extubation failure by a factor of 23.0 (95% CI, 3.34-158.5). Conclusion: COVID-19 patients had an extubation failure risk that was almost three times higher than non-COVID-19 patients, with the extubation of the former being delayed compared to the latter. Furthermore, an age ≥ 66 years, time of symptoms ≥ 31 days, need of dialysis, and PaO2/FiO2 ratio > 200 were independent predictors for extubation failure, and the presence of three of these characteristics increased the risk of failure by a factor of 23.0.

Prolonged Mechanical Ventilation: Outcomes and Management

The number of patients requiring prolonged mechanical ventilation (PMV) is increasing worldwide, placing a burden on healthcare systems. Therefore, investigating the pathophysiology, risk factors, and treatment for PMV is crucial. Various underlying comorbidities have been associated with PMV. The pathophysiology of PMV includes the presence of an abnormal respiratory drive or ventilator-induced diaphragm dysfunction. Numerous studies have demonstrated that ventilator-induced diaphragm dysfunction is related to increases in in-hospital deaths, nosocomial pneumonia, oxidative stress, lung tissue hypoxia, ventilator dependence, and costs. Thus far, the pathophysiologic evidence for PMV has been derived from clinical human studies and experimental studies in animals. Moreover, recent studies have demonstrated the outcome benefits of pharmacological agents and rehabilitative programs for patients requiring PMV. However, methodological limitations affected these studies. Controlled prospective studies with an adequate number of participants are necessary to provide evidence of the mechanism, prognosis, and treatment of PMV. The great epidemiologic impact of PMV and the potential development of treatment make this a key research field.

The Feasibility of a Machine Learning Approach in Predicting Successful Ventilator Mode Shifting for Adult Patients in the Medical Intensive Care Unit

Background and Objectives: Traditional assessment of the readiness for the weaning from the mechanical ventilator (MV) needs respiratory parameters in a spontaneous breath. Exempted from the MV disconnecting and manual measurements of weaning parameters, a prediction model based on parameters from MV and electronic medical records (EMRs) may help the assessment before spontaneous breath trials. The study aimed to develop prediction models using machine learning techniques with parameters from the ventilator and EMRs for predicting successful ventilator mode shifting in the medical intensive care unit. Materials and Methods: A retrospective analysis of 1483 adult patients with mechanical ventilators for acute respiratory failure in three medical intensive care units between April 2015 and October 2017 was conducted by machine learning techniques to establish the predicting models. The input candidate parameters included ventilator setting and measurements, patients’ demographics, arterial blood gas, laboratory results, and vital signs. Several classification algorithms were evaluated to fit the models, including Lasso Regression, Ridge Regression, Elastic Net, Random Forest, Extreme Gradient Boosting (XGBoost), Support Vector Machine, and Artificial Neural Network according to the area under the Receiver Operating Characteristic curves (AUROC). Results: Two models were built to predict the success shifting from full to partial support ventilation (WPMV model) or from partial support to the T-piece trial (sSBT model). In total, 3 MV and 13 nonpulmonary features were selected for the WPMV model with the XGBoost algorithm. The sSBT model was built with 8 MV and 4 nonpulmonary features with the Random Forest algorithm. The AUROC of the WPMV model and sSBT model were 0.76 and 0.79, respectively. Conclusions: The weaning predictions using machine learning and parameters from MV and EMRs have acceptable performance. Without manual measurements, a decision-making system would be feasible for the continuous prediction of mode shifting when the novel models process real-time data from MV and EMRs.

Paradox of trimethylamine-N-oxide, the impact of malnutrition on microbiota-derived metabolites and septic patients

Background

Trimethylamine N-oxide (TMAO) is a microbiota-derived metabolite, which is linked to vascular inflammation and atherosclerosis in cardiovascular (CV) diseases. But its effect in infectious diseases remains unclear. We conducted a single-center prospective study to investigate association of TMAO with in-hospital mortality in septic patients admitted to an intensive care unit (ICU).

Methods

Totally 95 septic, mechanically ventilated patients were enrolled. Blood samples were obtained within 24 h after ICU admission, and plasma TMAO concentrations were determined. Septic patients were grouped into tertiles according to TMAO concentration. The primary outcome was in-hospital death, which further classified as CV and non-CV death. Besides, we also compared the TMAO concentrations of septic patients with 129 non-septic patients who were admitted for elective coronary angiography (CAG).

Results

Septic patients had significantly lower plasma TMAO levels than did subjects admitted for CAG (1.0 vs. 3.0 μmol/L, p < 0.001). Septic patients in the lowest TMAO tertile (< 0.4 μmol/L) had poorer nutrition status and were given longer antibiotic courses before ICU admission. Circulating TMAO levels correlated positively with daily energy intake, the albumin and prealbumin concentration. Compared with those in the highest TMAO tertile, septic patients in the lowest TMAO tertile were at greater risk of non-CV death (hazard ratio 2.51, 95% confidence interval 1.21–5.24, p = 0.014). However, TMAO concentration was no longer an independent predictor for non-CV death after adjustment for disease severity and nutritional status.

Conclusion

Plasma TMAO concentration was inversely associated with non-CV death among extremely ill septic patients, which could be characterized as TMAO paradox. For septic patients, the impact of malnutrition reflected by circulating TMAO levels was greater than its pro-inflammatory nature.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-021-00581-5.

Long-Term Survival and Medical Costs of Patients with Prolonged Mechanical Ventilation and Tracheostomy: A Nationwide Cohort Study

Few large-scale studies have focused on tracheostomy in patients with prolonged mechanical ventilation. This retrospective population-based study extracted data from the longitudinal National Health Insurance Research Database in Taiwan to compare long-term mortality between patients on prolonged mechanical ventilation with and without tracheostomy and their related medical expenditures. Data on newly developed respiratory failure in patients on ventilator support were extracted from 1 January 2002 to 31 December 2008. Of 10,705 patients included, 1372 underwent tracheostomy (n = 563) or translaryngeal intubation (n = 779). Overall survival of the patients with tracheostomy was followed for 5 years. Average survival was 4.98 years for the patients with tracheostomy and 5.48 years for the patients with translaryngeal intubation (not significant). Sex, age, premium-based monthly salary difference, occupation, urbanization level, chronic obstructive pulmonary disease, chronic heart failure, chronic renal disease, and cerebrovascular diseases were significantly associated with mortality for endotracheal intubation. Male sex, chronic heart failure, chronic renal disease, age ≥45 years, and low income were associated with significantly higher mortality. Although total medical expenditures were higher for the patients with tracheostomy, annual medical expenditures were not significantly different. There were no differences in long-term mortality between the two groups.

The Long-Term Survival of Successfully Weaned Prolonged Mechanical Ventilation Patients

Background

There are rare articles in the literature that addressed long-term survival in successfully weaned prolonged mechanical ventilation patients. How are the long-term outcomes of these successfully weaned prolonged mechanical ventilation patients? Our objective is to explore this issue in depth in this study and serve as the basis for us to provide suggestions for patients in long-term care of the successfully weaned prolonged mechanical ventilation patients.

Methods

We investigated the clinical variables, long-term survival, cause of death, receipt or not of tracheostomy and analyzed the factors association with survival in successfully weaned prolonged mechanical ventilation patients.

Results

We can further gather long-term follow-up data on successfully weaned prolonged mechanical ventilation patients, 243 patients. The 1-, 2-, 3-, 4- and 5-year survival rates of successfully weaned PMV patients were 32.5%, 28.0%, 24.9%, 23.9%, and 21.3%, respectively. The factors between successfully weaned prolonged mechanical ventilation patients who died in the ward and those who were discharged from the hospital revealed the poorer survival of patients who died in the ward was due to a higher percentage of end-stage renal disease comorbidity, a higher percentage of ≥4 comorbidities and a lower percentage of undergoing tracheostomy. The factors between successfully weaned discharged prolonged mechanical ventilation patients who survived <1 year and those who survived ≥1 year revealed the poorer survival of patients who survived <1 year was due to older age, a higher percentage of ≥4 comorbidities, and a lower percentage of undergoing tracheostomy.

Conclusion

The receipt or not of tracheostomy is the key influential factor of long-term survival of successfully weaned prolonged mechanical ventilation patients. Tracheostomy should be attempted in suitable patients for improving long-term outcomes in successfully weaned prolonged mechanical ventilation patients.

Mechanical power normalized to lung-thorax compliance predicts prolonged ventilation weaning failure: a prospective study

Background

Mechanical power (MP) of artificial ventilation, the energy transferred to the respiratory system, is a chief determinant of adequate oxygenation and decarboxylation. Calculated MP, the product of applied airway pressure and minute ventilation, may serve as an estimate of respiratory muscle workload when switching to spontaneous breathing. The aim of the study was to assess MP’s discriminatory performance in predicting successful weaning from prolonged tracheostomy ventilation.

Methods

Prospective, observational study in 130 prolonged mechanically ventilated, tracheotomized patients in a specialized weaning center. Predictive weaning outcome ability of arterial blood gas analyses and indices derived from calculated MP at beginning and end of weaning was determined in terms of area under receiver operating characteristic curve (AUROC) and measures derived from k-fold cross-validation (likelihood ratios, diagnostic odds ratio, F₁ score, and Matthews correlation coefficient [MCC]).

Results

Forty-four (33.8%) patients experienced weaning failure. Absolute MP showed poor discrimination in predicting outcome; whereas specific MP (MP normalized to dynamic lung-thorax compliance, LTC_dyn-MP) had moderate diagnostic accuracy (MCC 0.38; AUROC 0.79, 95%CI [0.71‒0.86], p < 0.001), further improved by correction for corresponding mechanical ventilation P_aCO₂ (termed the power index of the respiratory system [PI_rs]: MCC 0.52; AUROC 0.86 [0.79‒0.92], p < 0.001). Diagnostic performance of MP indices increased over the course of weaning, with maximum accuracy immediately before completion (LTC_dyn-MP: MCC 0.49; AUROC 0.86 [0.78‒0.91], p < 0.001; PI_rs: MCC 0.68; AUROC 0.92 [0.86‒0.96], p < 0.001).

Conclusions

MP normalized to dynamic lung-thorax compliance, a surrogate for applied power per unit of ventilated lung volume, accurately discriminated between low and high risk for weaning failure following prolonged mechanical ventilation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01566-8.

Prediction of extubation outcome in mechanically ventilated patients: Development and validation of the Extubation Predictive Score (ExPreS)

Despite the best efforts of intensive care units (ICUs) professionals, the extubation failure rates in mechanically ventilated patients remain in the range of 5%–30%. Extubation failure is associated with increased risk of death and longer ICU stay. This study aimed to identify respiratory and non-respiratory parameters predictive of extubation outcome, and to use these predictors to develop and validate an “Extubation Predictive Score (ExPreS)” that could be used to predict likelihood of extubation success in patients receiving invasive mechanical ventilation (IMV). Derivation cohort was composed by patients aged ≥18 years admitted to the ICU and receiving IMV through an endotracheal tube for >24 hours. The weaning process followed the established ICU protocol. Clinical signs and ventilator parameters of patients were recorded during IMV, in the end phase of weaning in pressure support ventilation (PSV) mode, with inspiratory pressure of 7 cm H₂O over the PEEP (positive end expiratory pressure). Patients who tolerated this ventilation were submitted to spontaneous breathing trial (SBT) with T-tube for 30 minutes. Those who passed the SBT and a subsequent cuff-leak test were extubated. The primary outcome of this study was extubation success at 48 hours. Parameters that showed statistically significant association with extubation outcome were further investigated using the receiver operating characteristics (ROC) analysis to assess their predictive value. The area under the curve (AUC) values were used to select parameters for inclusion in the ExPreS. Univariable logistic regression analysis and ROC analysis were performed to evaluate the performance of ExPreS. Patients’ inclusion and statistical analyses for the prospective validation cohort followed the same criteria used for the derivation cohort and the decision to extubate was based on the ExPreS result. In the derivation cohort, a total of 110 patients were extubated: extubation succeeded in 101 (91.8%) patients and failed in 9 (8.2%) patients. Rapid shallow-breathing index (RSBI) in SBT, dynamic lung compliance, duration of IMV, muscle strength, estimated GCS, hematocrit, and serum creatinine were significantly associated with extubation outcome. These parameters, along with another parameter—presence of neurologic comorbidity—were used to create the ExPreS. The AUC value for the ExPreS was 0.875, which was higher than the AUCs of the individual parameters. The total ExPreS can range from 0 to 100. ExPreS ≥59 points indicated high probability of success (OR = 23.07), while ExPreS ≤44 points indicated low probability of success (OR = 0.82). In the prospective validation cohort, 83 patients were extubated: extubation succeeded in 81 (97.6%) patients and failed in 2 (2.4%) patients. The AUC value for the ExPreS in this cohort was 0.971. The multiparameter score that we propose, ExPreS, shows good accuracy to predict extubation outcome in patients receiving IMV in the ICU. In the prospective validation, the use of ExPreS decreased the extubation failure rate from 8.2% to 2.4%, even in a cohort of more severe patients.

Clinical outcomes and prognostic factors for prolonged mechanical ventilation in patients with acute stroke and brain trauma

BACKGROUND/PURPOSE

Neurological dysfunction is a common condition necessitating prolonged mechanical ventilation (PMV). We investigated the clinical features and outcomes of patients with acute neurological diseases requiring PMV.

METHODS

This retrospective observational study was conducted at the Respiratory Care Center (RCC) of Chang Gung Memorial Hospital, Taiwan, between January 2011 and January 2014. The main outcome was weaning success, defined as successful withdrawal from mechanical ventilator support for more than 5 days.

RESULTS

The study included 103 patients with acute stroke and brain trauma receiving PMV. Weaning success was reported in 63 (61%) patients and weaning failure was reported in 40 (39%) patients. Patients in the weaning failure group were older and had a lower RCC Glasgow Coma Scale (GCS) score (6.0 vs 7.9, p = 0.005), lower albumin level (2.8 vs 3.1, p = 0.015), longer RCC stay (28.7 vs 21.3 days, p = 0.017), and higher in-hospital mortality rate (47% vs 9%, p < 0.01). Multivariate analysis revealed that reduced RCC GCS score is an independent prognostic factor for weaning failure (odds ratio [OR] = 1.22, 95% confidence interval [CI] = 1.05-1.46, p = 0.016) and that per unit increase of RCC GCS score is associated with a lower risk of in-hospital mortality (OR = 0.83, 95% CI = 0.70-0.96, p = 0.019).

CONCLUSION

Reduced RCC GCS score is an independent prognostic factor for weaning failure, and is associated with increased in-hospital mortality rates in patients with acute stroke and brain trauma requiring PMV.

Value of modified Burns Wean Assessment Program scores in the respiratory intensive care unit: an Egyptian study

Background

There is no consensus on the most useful predictive indicator for weaning patients from mechanical ventilation (MV). We aimed to evaluate the utility of the modified Burns Wean Assessment Program (m-BWAP) in predicting the weaning success in patients with respiratory disorders admitted to the respiratory intensive care unit (RICU).

Methods

Patients with respiratory failure requiring MV for longer than 48 hours were included. They were weaned by pressure support ventilation and spontaneous breathing trails. Patients were divided into successful and unsuccessful weaning groups according to their outcomes.

Results

A total of 91 patients were enrolled. The majority had chronic obstructive pulmonary diseases (COPD): 40%, overlap syndrome (24%), and obesity hypoventilation syndrome (OHS): 15%. The successful group had significantly higher m-BWAP scores than that in the unsuccessful group (median 65; range 35 to 80 vs. median 45; range 30 to 65; p=0.000), with area under the curve (AUC) of 0.854; 95% CI 0.766 to 0.919), p<0.001. At cut-off value of ≥55, the sensitivity and specificity of m-BWAP to predict successful weaning were 73.77% and 84.85%, respectively. The AUC for m-BWAP was significantly higher than that for rapid shallow breathing index (RSBI).

Conclusion

We conclude that m-BWAP scores represent a good predictor of weaning success among patients with chronic respiratory disorders in the RICU. The m-BWAP checklist has many factors that are closely related to the weaning outcomes of patients with chronic respiratory disorders. Further, large-scale, multicenter studies are warranted.

Use of the modified Glasgow Coma Scale score to guide sequential invasive-noninvasive mechanical ventilation weaning in patients with AECOPD and respiratory failure

Sequential invasive-noninvasive ventilation (NIV) improves the outcomes of patients with respiratory failure caused by acute exacerbation of chronic obstructive pulmonary disease (AECOPD); however, there is no clear consensus on the optimal timing of the switch to sequential invasive-NIV in these patients. In the present study, a potential role for the modified Glasgow Coma Scale (GCS) score to guide sequential weaning was investigated. Patients with AECOPD and respiratory failure were prospectively recruited from three study centers (Wenling Hospital Affiliated to Wenzhou Medical University, the First Affiliated Hospital of Wenzhou Medical University and Changsha Central Hospital) between January 1st 2016 and December 31st 2018. Patients were randomly assigned to group A and B, with the switching point for sequential weaning strategy in the two groups being a modified GCS score ≥13 and 10 points, respectively. Each group included 240 patients. Baseline demographic characteristics were comparable in the two groups. The duration of invasive mechanical ventilation (IMV) in group A was significantly shorter than that in group B. However, there were no significant between-group differences with respect to the incidence of re-intubation, ventilator-associated pneumonia, in-hospital mortality or the length of hospital stay. Use of a modified GCS score ≥13 as the switching point for sequential invasive-NIV may help decrease the duration of IMV in patients with AECOPD and respiratory failure.

How prolonged mechanical ventilation is a neglected disease in chest medicine: a study of prolonged mechanical ventilation based on 6 years of experience in Taiwan

Background:

An increasing number of patients require prolonged mechanical ventilation (PMV) to survive recovery from critical care. It should be emphasized that PMV is a neglected disease in chest medicine. We investigated 6 years of clinical outcomes and long-term survival rates of patients who required PMV.

Methods:

We analyzed retrospectively data from patients in respiratory care center (RCC) to investigate the main causes of respiratory failure leading patients to require PMV. We also studied the factors that influence the ventilator weaned rate, factors that influence the long-term ventilator dependence of patients who require PMV, as well as patients’ hospital mortality and long-term survival rates.

Results:

A total of 574 patients were admitted to RCC during the 6 years. Of these, 428 patients (74.6%) were older than 65 years. A total of 391 patients (68.1%) were successfully weaned from the ventilator while 83 patients (14.4%) were unsuccessfully weaned. A total of 95 patients (16.6%) died during RCC hospitalization. The most common cause of acute respiratory failure leading to patients requiring PMV was pneumonia. The factor that affected whether patients were successfully weaned from the ventilator was the cause of the respiratory failure that lead patients to require PMV. Our hospital mortality rate was 32.4%; the 1-year survival rate was 24.3%. There was a strong correlation between higher patient age and higher hospital mortality rate and poor 1-year survival rate. Patients with no comorbidity demonstrated good 1-year survival rates. Patients with four comorbidities and patients with end-stage renal disease requiring hemodialysis comorbidity showed poor 1-year survival rates.

Conclusions:

The factor that affected whether patients were successfully weaned from the ventilator was the cause of the respiratory failure that lead patients to require PMV. Older patients, patients with renal failure requiring hemodialysis, and those with numerous comorbidities demonstrated poor long-term survival.

The reviews of this paper are available via the supplemental material section.

Middle Range Theory for the Nursing Diagnosis of Dysfunctional Ventilatory Weaning Response

PURPOSE

To propose a middle range theory (MRT) that establishes the theoretical basis for the nursing diagnosis dysfunctional ventilatory weaning response (DVWR) (00034).

DATA SOURCES

Integrative literature review.

DATA SYNTHESIS

The MRT includes the main concepts, pictorial diagrams, propositions, and causal relationships for use in clinical practice.

CONCLUSIONS

The MRT developed for the DVWR allowed us to list 13 clinical antecedent and 21 consequent findings related to this nursing diagnosis that occurs when ventilatory weaning fails.

IMPLICATIONS FOR NURSING PRACTICE

The clinical indicators and causal relationships described in the MRT may serve as a basis for nurses to understand the dysfunctional weaning process.

Maximal expiratory pressure is associated with reinstitution of mechanical ventilation after successful unassisted breathing trials in tracheostomized patients with prolonged mechanical ventilation

Objective

Reinstitution of mechanical ventilation (MV) for tracheostomized patients after successful weaning may occur as the care setting changes from critical care to general care. We aimed to investigate the occurrence, consequence and associated factors of MV reinstitution.

Methods

We analyzed the clinical data and physiological measurements of tracheostomized patients with prolonged MV discharged from the weaning unit to general wards after successful weaning to compare between those with and without in-hospital MV reinstitution within 60 days.

Results

Of 454 patients successfully weaned, 116 (25.6%) reinstituted MV at general wards within 60 days; at hospital discharge, 42 (36.2%) of them were eventually liberated from MV, 51 (44.0%) remained MV dependent, and 33 (28.4%) died. Of the 338 patients without reinstitution within 60 days, only 3 (0.9%) were later reinstituted with MV before discharge (on day 67, 89 and 136 at general wards, respectively), and 322 (95.2%) were successfully weaned again at discharge, while 13 (3.8%) died. Patients with MV reinstitution had a significantly lower level of maximal expiratory pressure (P_Emax) before unassisted breathing trial compared to those without reinstitution. Multivariable Cox regression analysis showed fever at RCC discharge (hazard ratio [HR] 14.00, 95% confidence interval [CI] 3.2–61.9) chronic obstructive pulmonary disease (HR 2.37, 95% CI 1.34–4.18), renal replacement therapy at the ICU (HR 2.29, 95% CI 1.50–3.49) and extubation failure before tracheostomy (HR 1.76, 95% CI 1.18–2.63) were associated with increased risks of reinstitution, while P_Emax > 30 cmH₂O (HR 0.51, 95% CI 0.35–0.76) was associated with a decreased risk of reinstitution.

Conclusions

The reinstitution of MV at the general ward is significant, with poor outcomes. The P_Emax measured before unassisted breathing trial was significantly associated with the risk of reinstituting MV at the general wards.

Transitional Percentage of Minute Volume as a Novel Predictor of Weaning from Mechanical Ventilation in Patients with Chronic Respiratory Failure

PURPOSE

Some patients with respiratory failure fail initial weaning attempts and need prolonged mechanical ventilation (MV). Prolonged MV is associated with many complications and consumption of heathcare resources. Objective weaning indices help staffs to identify high-potential patients for weaning from the MV. Traditional weaning indices are not reliable in clinical practice. Transitional percentage of minute volume (TMV%) is a new index of the work of breathing. This study aimed to investigate the utility of TMV% in the prediction of weaning potential.

METHODS

This study was prospectively performed including all patients with prolonged MV. Researchers recorded their demographics, TMV%, respiratory parameters, Acute Physiology and Chronic Health Evaluation II score, and laboratory data upon arrival at the respiratory care center. The factors associated with successful weaning were analyzed.

RESULTS

Out of the 120 patients included, 84 (70.0%) were successfully weaned from MV. Traditional weaning indices such as rapid shallow breathing index could not predict the weaning outcome. TMV% was a valuable parameter as patients with a lower TMV%, higher tidal volume, higher hemoglobin, lower blood urea nitrogen, and lower Acute Physiology and Chronic Health Evaluation II scores had a higher rate of successful weaning. TMV%, tidal volume, and HCO3- levels were independent predictors of successful weaning, and the area under the curve was .79 in the logistic regression model.

CONCLUSION

TMV% is a novel and effective predictor of successful weaning. Patients with lower TMV% had a higher MV weaning outcome. Once patients with a high potential for successful weaning are identified, they should be aggressively weaned from MV as soon as possible.

CLINICAL TRIALS GOVERNMENT IDENTIFIER

NCT033480.

The association between airflow limitation and blood eosinophil levels with treatment outcomes in patients with chronic obstructive pulmonary disease and prolonged mechanical ventilation

The clinical implications of airflow limitation severity and blood eosinophil level in patients with chronic obstructive pulmonary disease (COPD) and prolonged mechanical ventilation (PMV) are unknown. Thus, this study aimed to identify whether or not these two indicators were significantly associated with short-term in-respiratory care center (RCC) treatment outcomes in this population. Of all participants (n = 181) in this retrospective cross-sectional study, 41.4%, 40.9%, 8.3%, and 52.5% had prolonged RCC admission (RCC length of stay >21 days), failed weaning, death, and any adverse outcomes of interest, respectively. Compared to participants without any adverse outcomes of interest, moderate (the Global Initiative for Chronic Obstructive Lung Disease (GOLD) II) and/or severe (GOLD III) airflow limitation were significantly associated with short-term in-RCC adverse outcomes in terms of failed weaning (for III versus I, OR = 15.06, p = 0.003) and having any adverse outcomes of interest (for II versus I, OR = 17.66, p = 0.002; for III versus I, OR = 37.07, p = 0.000) though the severity of airflow limitation did not have associations with prolonged RCC admission and death after adjustment. Meanwhile, blood eosinophilia defined by various cut-off values was not associated with any adverse outcomes. The findings have significant clinical implications and are useful in the management of patients with COPD and PMV.

Alterations in diaphragmatic function assessed by ultrasonography in mechanically ventilated patients with sepsis

PURPOSE

To assess alteration of diaphragmatic function by ultrasonography in a population of mechanically ventilated patients with or without sepsis.

METHODS

We performed a prospective, 6-month, single-center, observational cohort study. Mechanically ventilated septic and nonseptic patients were studied within 24 hours following intubation and before the moment of ventilator liberation. Diaphragm thickness and contractile activity (quantified by diaphragmatic thickening fraction, DTF) were measured by ultrasonography at the zone of apposition. Intraobserver and interobserver reproducibility were measured.

RESULTS

Fifty-two critically ill patients were included, 28 with sepsis and 24 without sepsis. Upon initiation of ventilation, DTF was lower in septic than that in nonseptic patients (P = 0.03). No difference was observed between septic and nonseptic patients for diaphragm thickness. Mean 188 ± 111 hours after the first measurement, both diaphragm thickness and DTF decreased significantly compared with first measurements in septic and nonseptic patients, all P < 0.001. Diaphragm thickness decreased by 9.1 ± 10.7% in nonseptic and by 16.0 ± 13.5% in septic patients, P = 0.049. DTF decreased by 15.2 ± 21.3% in nonseptic and by 30.7 ± 22.0% in septic patients, P = 0.013.

CONCLUSIONS

Mechanically ventilated patients with sepsis were associated with an earlier and more severe diaphragm dysfunction compared with patients without sepsis.

Chronic Comorbid Illnesses Predict the Clinical Course of 866 Patients Requiring Prolonged Mechanical Ventilation in a Long-Term, Acute-Care Hospital

OBJECTIVE

To determine whether burdens of chronic comorbid illnesses can predict the clinical course of prolonged mechanical ventilation (PMV)patients in a long-term, acute-care hospital (LTACH).

METHODS

Retrospective study of 866 consecutive PMV patients whose burdens of chronic comorbid illnesses were quantified using the Cumulative Illness Rating Scale (CIRS). Based on increasing CIRS scores, 6 groups were formed and compared: group A (≤25; n = 97), group B (26-28; n = 105), group C (29-31; n = 181), group D (32-34; n = 208), group E (35-37; n = 173), and group F (>37; n = 102).

RESULTS

As CIRS scores increased from group A to group F, rates of weaning success, home discharges, and LTACH survival declined progressively from 74% to 17%, 48% to 0%, and 79% to 21%, respectively (all P < .001). Negative correlations between the mean score of each CIRS group and correspondent outcomes also supported patients' group allocation and an accurate prediction of their clinical course (all P < .01). Long-term survival progressively declined from a median survival time of 38.9 months in group A to 3.2 months in group F (P < .001). Compared to group A, risk of death was 75% greater in group F (P = .03). Noteworthy, PMV patients with CIRS score <25 showed greater ability to recover and a low likelihood of becoming chronically critically ill. Diagnostic accuracy of CIRS to predict likelihood of weaning success, home discharges, both LTACH and long-term survival was good (area under the curves ≥0.71; all P <.001).

CONCLUSIONS

The burden of chronic comorbid illnesses was a strong prognostic indicator of the clinical course of PMV patients. Patients with lower CIRS values showed greater ability to recover and were less likely to become chronically critically ill. Thus, CIRS can be used to help guide clinicians caring for PMV patients in transfer decisions to and from postacute care setting.

Predictive factors of weaning from mechanical ventilation and extubation outcome: A systematic review

PURPOSE

To identify, describe and discuss the parameters used to predict weaning from mechanical ventilation and extubation outcomes.

METHODS

Systematic review of scientific articles using four electronic databases: PubMed, Embase, PEDro and Cochrane Library. Search terms included "weaning", "extubation", "withdrawal" and "discontinuation", combined with "mechanical ventilation" and "predictive factors", "predictive parameters" and "predictors for success". In this study, we included original articles that presented predictive factors for weaning or extubation outcomes in adult patients and not restricted to a single disease. Articles not written in English were excluded.

RESULTS

A total of 43 articles were included, with a total of 7929 patients and 56 different parameters related to weaning and extubation outcomes. Rapid Shallow Breathing Index (RSBI) was the most common predictor, discussed in 15 studies (2159 patients), followed by Age and Maximum Inspiratory Pressure in seven studies. The other 53 parameters were found in less than six studies.

CONCLUSION

There are several parameters used to predict weaning and extubation outcomes. RSBI was the most frequently studied and seems to be an important measurement tool in deciding whether to wean/extubate a patient. Furthermore, the results demonstrated that weaning and extubation should be guided by several parameters, and not only to respiratory ones.

Propensity score-matching analyses on the effectiveness of integrated prospective payment program for patients with prolonged mechanical ventilation

OBJECTIVES

An integrated delivery system with a prospective payment program (IPP) for prolonged mechanical ventilation (PMV) was launched by Taiwan's National Health Insurance (NHI) due to the costly and limited ICU resources. This study aimed to analyze the effectiveness of IPP and evaluate the factors associated with successful weaning and survival among patients with PMV.

METHODS

Taiwan's NHI Research Database was searched to obtain the data of patients aged ≥17 years who had PMV from 2006 to 2010 (N=50,570). A 1:1 propensity score matching approach was used to compare patients with and without IPP (N=30,576). Cox proportional hazards modeling was used to examine the factors related to successful weaning and survival.

RESULTS

The related factors of lower weaning rate in IPP participants (hazard ratio [HR]=0.84), were older age, higher income, catastrophic illness (HR=0.87), and higher comorbidity. The effectiveness of IPP intervention for the PMV patients showed longer days of hospitalization, longer ventilation days, higher survival rate, and higher medical costs (in respiratory care center, respiratory care ward). The 6-month mortality rate was lower (34.0% vs. 32.9%). The death risk of IPP patients compared to those non-IPP patients was lower (HR=0.91, P<0.001).

CONCLUSIONS

The policy of IPP for PMV patients showed higher survival rate although it was costly and related to lower weaning rate.

Factors influencing weaning from mechanical ventilation in neurological and neurosurgical early rehabilitation patients

BACKGROUND

Studies analyzing risk factors of weaning failure in neurological and neurosurgical early rehabilitation (NNER) patients are rare.

AIM

The aim of this study was to identify clinical factors influencing the weaning of NNER patients.

DESIGN

An observational, retrospective data analysis of a German multicenter study was performed.

SETTING

German neurological early rehabilitation centers.

POPULATION

Inpatient ventilated NNER patients (N.=192) were enrolled in the study.

METHODS

Demographical data, main diagnosis, medical devices, special medical care and assessment instruments of functional abilities, consciousness and independence in activities of daily living were accrued and compared between patients with and without successful weaning. The prognostic power of factors associated with weaning success/failure was analyzed using binary logistic regression.

RESULTS

In total, 75% of the patients were successfully weaned. Colonization with multi-drug resistant bacteria and the need for dialysis were independent predictors of weaning failure. Successfully weaned patients had a shorter length of stay, better functional outcome, and lower mortality than non-successfully weaned patients.

CONCLUSIONS

Successfully weaned patients differ from patients with weaning failure in several clinical variables. All these variables are associated with the morbidity of the patient, indicating that the weaning process is strongly influenced by disease burden.

CLINICAL REHABILITATION IMPACT

Functional abilities, level of consciousness, independence in activities of daily living, colonization with multi-drug resistant bacteria, need for dialysis and disease duration might help to predict the weaning process of NNER.

Renal Function, Weaning, and Survival in Patients With Ventilator-Dependent Respiratory Failure

BACKGROUND

Acute kidney injury in acute critical illness has been associated with poor weaning and survival outcomes. The relation between renal dysfunction as defined by creatinine clearance (CrCl) and weaning from prolonged mechanical ventilation (PMV) is not known. The objective of this study was to determine the relation of measured CrCl to weaning and survival in patients on PMV.

METHODS

We retrospectively studied 167 patients on PMV admitted to a long-term acute care facility for weaning over a 3-year period. Data obtained included age, gender, admission blood urea nitrogen (BUN), serum creatinine, CrCl, random urine creatinine (RUCr), and 24-hour urinary creatinine (24UCr). Renal dysfunction was defined as normal (CrCl > 90 mL/min), mild (CrCl 60-90 mL/min), moderate (CrCl 30-59 mL/min), and severe (CrCl < 30 mL/min). Primary outcome measured was liberation from PMV, defined as being off ventilator for >7 days. Survival, defined as being alive at discharge, time to wean, and time to discharge alive were secondary outcomes. The association between the studied parameters and outcomes was determined by unpaired t test. The predictive value of studied parameters for weaning and survival was determined by multivariate logistic regression analysis. P < .05 was statistically significant.

RESULTS

Mean age was 68.5 (14) years; 49% were males; 64% were liberated and 65.8% survived. Blood urea nitrogen, RUCr, 24Ucr, and CrCl had a significant association with successful weaning. These parameters (except BUN) also had a significant association with survival. A better outcome occurred with CrCl > 90 mL/min.

CONCLUSION

Measured CrCl has a significant relation to successful weaning and survival in patients on PMV and may be useful in prognosticating their outcome.

Noninvasive ventilation for avoidance of reintubation in patients with various cough strength

Background

Reintubation is associated with high mortality. Identification of methods to avoid reintubation is needed. The aim of this study was to assess whether prophylactic noninvasive ventilation (NIV) would benefit patients with various cough strengths.

Methods

We prospectively enrolled 356 patients who successfully passed a spontaneous breathing trial in a respiratory intensive care unit. Before extubation, cough peak flow was measured. After extubation, attending physicians determined whether the patients would receive prophylactic NIV or conventional oxygen treatment (control group). Patients were followed up to 90 days postextubation or death, whichever came first.

Results

The median value of cough peak flow was 70 L/minute. Among the patients with cough peak flow ≤70 L/minute, 108 received NIV and 72 received conventional oxygen treatment. In this cohort, NIV reduced reintubation (9 % vs. 35 % at postextubation 72 h, p < 0.01; and 24 % vs. 49 % at postextubation 7 days, p < 0.01) and postextubation 90-day mortality (43 % vs. 61 %, p = 0.02) compared with the control group. Further, use of NIV was an independent protective factor for reintubation (OR = 0.19, p < 0.01 at 72 h postextubation; and OR = 0.33, p < 0.01 at 7 days postextubation) and for death at 90 days postextubation (OR = 0.40, p = 0.02). Among patients with cough peak flow >70 L/minute, 71 received NIV and 105 received conventional oxygen treatment. In this cohort, NIV did not reduce reintubation (6 % vs. 6 % at 72 h postextubation, p > 0.99; and 9 % vs. 9 % at 7 days postextubation, p > 0.99) or postextubation 90-day mortality (21 % vs. 15 %, p = 0.32) compared with the control group. Further, use of NIV was not associated with reintubation or postextubation 90-day mortality.

Conclusion

In a planned extubated population, prophylactic NIV benefited patients with weak cough but possibly not in patients with strong cough.

Elevated Red Cell Distribution Width Is Associated With Decreased Ventilator-Free Days in Critically Ill Patients

INTRODUCTION

Elevated red cell distribution width (RDW) is associated with mortality in a variety of respiratory conditions. Recent data also suggest that RDW is associated with mortality in intensive care unit (ICU) patients. Although respiratory failure is common in the ICU, the relationship between RDW and pulmonary outcomes in the ICU has not been previously explored. Therefore, our goal was to investigate the association of admission RDW with 30-day ventilator-free days (VFDs) in ICU patients.

METHODS

We performed a retrospective analysis from an ongoing prospective, observational study. Patients were recruited from medical and surgical ICUs of a large teaching hospital in Boston, Massachusetts. The RDW was assessed within 1 hour of ICU admission. Poisson regression analysis was used to investigate the association of RDW (normal: 11.5%-14.5% vs elevated: >14.5%) with 30-day VFD, while controlling for age, sex, race, body mass index, Nutrition Risk in the Critically Ill score, the presence of chronic lung disease, Pao₂/Fio₂ ratio, and admission levels of hemoglobin, mean corpuscular volume, phosphate, albumin, C-reactive protein, and creatinine.

RESULTS

A total of 637 patients comprised the analytic cohort. Mean RDW was 15 (standard deviation 4%), with 53% of patients in the normal range and 47% with elevated levels. Median VFD was 16 (interquartile range: 6-25) days. Poisson regression analysis demonstrated that ICU patients with elevated admission RDW were likely to have 32% lower 30-day VFDs compared to their counterparts with RDW in the normal range (incidence rate ratio: 0.68; 95% confidence interval: 0.55-0.83: P < .001).

CONCLUSIONS

We observed an inverse association of RDW and 30-day VFD, despite controlling for demographics, nutritional factors, and severity of illness. This supports the need for future studies to validate our findings, understand the physiologic processes that lead to elevated RDW in patients with respiratory failure, and determine whether changes in RDW may be used to support clinical decision-making.

Effects of Lung Expansion Therapy on Lung Function in Patients with Prolonged Mechanical Ventilation

Common complications in PMV include changes in the airway clearance mechanism, pulmonary function, and respiratory muscle strength, as well as chest radiological changes such as atelectasis. Lung expansion therapy which includes IPPB and PEEP prevents and treats pulmonary atelectasis and improves lung compliance. Our study presented that patients with PMV have improvements in lung volume and oxygenation after receiving IPPB therapy. The combination of IPPB and PEEP therapy also results in increase in respiratory muscle strength. The application of IPPB facilitates the homogeneous gas distribution in the lung and results in recruitment of collapsed alveoli. PEEP therapy may reduce risk of respiratory muscle fatigue by preventing premature airway collapse during expiration. The physiologic effects of IPPB and PEEP may result in enhancement of pulmonary function and thus increase the possibility of successful weaning from mechanical ventilator during weaning process. For patients with PMV who were under the risk of atelectasis, the application of IPPB may be considered as a supplement therapy for the enhancement of weaning outcome during their stay in the hospital.

An Overview of the Predictor Standard Tools for Patient Weaning from Mechanical Ventilation

Most patients staying in the intensive care unit (ICU) require respiratory support through a ventilator. Since prolonged mechanical ventilation and weaning from the ventilator without criteria or at the inappropriate time can result in many complications, it is required that patients be weaned off the ventilator as soon as possible. This study was conducted to investigate a few standard tools that predict successful and timely weaning of patients from the ventilator. In the literature, SOFA and APACHE II scores, along with various tools, including Burn, Morganroth, and Corgian, have been used in weaning patients from the ventilator. In most of these studies, the increase or decrease in the APACHE II score was correlated with the patient’s weaning time, and this score could be used as a criterion for weaning. Several authors have expressed their belief that the SOFA score in the ICU is a good indicator of the prognosis of patient’s weaning from the ventilator, length of stay, mortality, and rate of recovery. Several studies have compared SOFA and APACHE II scores and have shown that there is a positive correlation between the SOFA and APACHE II scores and that both mortality and dependence on the ventilator are related to these two scores. Another tool is Burn’s weaning program. A higher Burn score indicates successful weaning off of the ventilator, successful extubation, lower length of mechanical ventilation, and shorter stay in the hospital. However, the capabilities of the Morganroth scale and the Gluck and Corgian scoring systems were evaluated only for successful weaning off of the ventilator, and a decrease in the Morganroth and Gluck scores indicated successful weaning.

Nutritional Risk Screening 2002 as a Predictor of Outcome During General Ward-Based Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease with Respiratory Failure

BACKGROUND Noninvasive ventilation (NIV) may reduce the need for intubation and mortality associated with chronic obstructive pulmonary disease (COPD) with type II respiratory failure. Early and simple predictors of NIV outcome could improve clinical management. This study aimed to assess whether nutritional risk screening 2002 (NRS2002) is a useful outcome predictor in COPD patients with type II respiratory failure treated by noninvasive positive pressure ventilation (NIPPV). MATERIAL AND METHODS This prospective observational study enrolled COPD patients with type II respiratory failure who accepted NIPPV. Patients were submitted to NRS2002 evaluation upon admission. Biochemical tests were performed the next day and blood gas analysis was carried out prior to NIPPV treatment and 4 hours thereafter. Patients were divided into NRS2002 score ≥3 and NRS2002 score <3 groups and NIV failure rates were compared between both groups. RESULTS Of the 233 patients, 71 (30.5%) were not successfully treated by NIPPV. The failure rate was significantly higher in the NRS2002 score ≥3 group (35.23%) in comparison with patients with NRS2002 score <3 (15.79%) (p<0.05). Multivariate analysis indicated that PaCO2 (OR 1.25, 95%CI 1.172-1.671, p<0.05) prior to NIPPV treatment and NRS2002 score ≥3 (OR 1.76, 95%CI 1.303-2.374, p<0.05) were independent predictive factors for NIPPV treatment failure. CONCLUSIONS NRS2002 score ≥3 and PaCO2 values at admission may predict unsuccessful NIPPV treatment of COPD patients with type II respiratory failure and help to adjust therapeutic strategies. NRS2002 is a noninvasive and simple method for predicting NIPPV treatment outcome.

Economic Burden of Diabetes Mellitus on Patients with Respiratory Failure Requiring Mechanical Ventilation during Hospitalizations

OBJECTIVES

To examine the economic burden of diabetes mellitus (DM) on medical expenditure among patients with respiratory failure (RF) requiring mechanical ventilation during hospitalization.

METHODS

We extracted the data from Taiwan National Health Research Insurance Database for those adult patients on their first hospitalization for RF requiring mechanical ventilation between 2004 and 2010. We examined associations between medical expenditure and the presence of comorbid DM. We performed independent t tests, chi-square tests, and multivariate linear regression analysis to identify factors associated with excess medical expenditure.

RESULTS

Of 347,961 patients hospitalized with first occurrence of RF requiring mechanical ventilation, 123,023 (35.36%) patients were documented to have a previous diagnosis of DM. Patients with RF and DM were sicker and consumed more health care resources than did patients with RF without DM. After adjusting for the specified covariates, mechanically ventilated patients with RF and DM consumed at least US $618 more of total inpatient medical expenditure than did patients with RF without DM. There were statistically significant interactions between age and DM on their total inpatient medical expenditure regardless of discharge status.

CONCLUSIONS

DM was associated with more severe disease status and higher consumption of medical expenditure during hospitalizations among mechanically ventilated patients due to first occurrence of RF in Taiwan. These findings provide scientific evidence to facilitate appropriate resource allocation and formulate programs for higher quality of care in the future in Taiwan and other countries.

Diaphragm weakness in mechanically ventilated critically ill patients

Introduction

Studies indicate that mechanically ventilated patients develop significant diaphragm muscle weakness, but the etiology of weakness and its clinical impact remain incompletely understood. We assessed diaphragm strength in mechanically ventilated medical ICU patients, correlated the development of diaphragm weakness with multiple clinical parameters, and examined the relationship between the level of diaphragm weakness and patient outcomes.

Methods

Transdiaphragmatic twitch pressure (PdiTw) in response to bilateral magnetic stimulation of the phrenic nerves was measured. Diaphragm weakness was correlated with the presence of infection, blood urea nitrogen, albumin, and glucose levels. The relationship of diaphragm strength to patient outcomes, including mortality and the duration of mechanical ventilation for successfully weaned patients, was also assessed.

Results

We found that infection is a major risk factor for diaphragm weakness in mechanically ventilated medical ICU patients. Outcomes for patients with severe diaphragm weakness (PdiTw <10 cmH₂O) were poor, with a markedly increased mortality (49%) compared to patients with PdiTw ≥10 cmH₂O (7% mortality, P = 0.022). In addition, survivors with PdiTw <10 cmH₂O required a significantly longer duration of mechanical ventilation (12.3 ± 1.7 days) than those with PdiTw ≥10 cmH₂O (5.5 ± 2.0 days, P = 0.016).

Conclusions

Infection is a major cause of severe diaphragm weakness in mechanically ventilated patients. Moreover, diaphragm weakness is an important determinant of poor outcomes in this patient population.

Predictive parameters for weaning from mechanical ventilation

The use of predictive parameters for weaning from mechanical ventilation is a rather polemic topic, and the results of studies on this topic are divergent. Regardless of the use of these predictive parameters, the spontaneous breathing trial (SBT) is recommended. The objective of the present study was to review the utility of predictive parameters for weaning in adults. To that end, we searched the Medline, LILACS, and PubMed databases in order to review articles published between 1991 and 2009, in English or in Portuguese, using the following search terms: weaning/desmame, extubation/extubação, and weaning indexes/indices de desmame. The use of clinical impression is an inexact means of predicting weaning outcomes. The most widely used weaning parameter is the RR/tidal volume (V T) ratio, although this parameter presents heterogeneous results in terms of accuracy. Other relevant parameters are MIP, airway occlusion pressure (P0.1), the P0.1/MIP ratio, RR, V T, minute volume, and the index based on compliance, RR, oxygenation, and MIP. An index created in Brazil, the integrative weaning index, has shown high accuracy. Although recommended, the SBT is inaccurate, approximately 15% of extubation failures going unidentified in SBTs. The main limitations of the weaning indexes are related to their use in specific populations, the cut-off points selected, and variations in the types of measurement. Since the SBT and the clinical impression are not 100% accurate, the weaning parameters can be useful, especially in situations in which the decision as to weaning is difficult.

Predictors of successful decannulation using a tracheostomy retainer in patients with prolonged weaning and persisting respiratory failure

BACKGROUND

For percutaneously tracheostomized patients with prolonged weaning and persisting respiratory failure, the adequate time point for safe decannulation and switch to noninvasive ventilation is an important clinical issue.

OBJECTIVES

We aimed to evaluate the usefulness of a tracheostomy retainer (TR) and the predictors of successful decannulation.

METHODS

We studied 166 of 384 patients with prolonged weaning in whom a TR was inserted into a tracheostoma. Patients were analyzed with regard to successful decannulation and characterized by blood gas values, the duration of previous spontaneous breathing, Simplified Acute Physiology Score (SAPS) and laboratory parameters.

RESULTS

In 47 patients (28.3%) recannulation was necessary, mostly due to respiratory decompensation and aspiration. Overall, 80.6% of the patients could be liberated from a tracheostomy with the help of a TR. The need for recannulation was associated with a shorter duration of spontaneous breathing within the last 24/48 h (p < 0.01 each), lower arterial oxygen tension (p = 0.025), greater age (p = 0.025), and a higher creatinine level (p = 0.003) and SAPS (p < 0.001). The risk for recannulation was 9.5% when patients breathed spontaneously for 19-24 h within the 24 h prior to decannulation, but 75.0% when patients breathed for only 0-6 h without ventilatory support (p < 0.001). According to ROC analysis, the SAPS best predicted successful decannulation [AUC 0.725 (95% CI: 0.634-0.815), p < 0.001]. Recannulated patients had longer durations of intubation (p = 0.046), tracheostomy (p = 0.003) and hospital stay (p < 0.001).

CONCLUSION

In percutaneously tracheostomized patients with prolonged weaning, the use of a TR seems to facilitate and improve the weaning process considerably. The duration of spontaneous breathing prior to decannulation, age and oxygenation describe the risk for recannulation in these patients.

A nomogram for predicting surgical complications in bariatric surgery patients

BACKGROUND

To minimize morbidity and mortality associated with surgery risks in the obese patient, algorithms offer planning operative strategy. Because these algorithms often classify patients based on inadequate category granularity, outcomes may not be predicted accurately. We reviewed patient factors and patient outcomes for those who had undergone bariatric surgical procedures to determine relationships and developed a nomogram to calculate individualized patient risk.

METHODS

From the American College of Surgeons National Security Quality Improvement Program database, we identified 32,426 bariatric surgery patients meeting NIH criteria and treated between 2005 and 2008. We defined a composite binary outcome of 30-day postoperative morbidity and mortality. A predictive model based on preoperative variables was developed using multivariable logistic regression; a multiple imputation procedure allowed inclusions of observations with missing data. Model performance was assessed using the C-statistic. A calibration plot graphically assessed the agreement between predicted and observed probabilities in regard to 30-day morbidity/mortality.

RESULTS

The nomogram model was constructed for maximal predictive accuracy. The estimated C-statistic [95% confidence interval] for the predictive nomogram was 0.629 [0.614, 0.645], indicative of slight to moderate discriminative ability beyond that of chance alone, and the greatest impacts on the estimated probability of morbidity/mortality were determined to be age, body mass index, serum albumin, and functional status.

CONCLUSIONS

By accurately predicting 30-day morbidity and mortality, this nomogram may prove useful in patient preoperative counseling on postoperative complication risk. Our results additionally indicate that neither age nor presence of obesity-related comorbidities should exclude patients from bariatric surgery consideration.

Acute kidney injury on ventilator initiation day independently predicts prolonged mechanical ventilation in intensive care unit patients

PURPOSE

The purpose of this study is to identify the predictors for prolonged mechanical ventilation (PMV) of more than 21 days among intensive care unit (ICU) patients.

MATERIAL AND METHODS

A retrospective observational study was conducted in a respiratory ICU from December 2008 to November 2009. The outcome measurement was the occurrence of PMV. Acute kidney injury (AKI) was identified and defined as an increase in the serum creatinine level of 50% or greater from baseline.

RESULTS

Of 154 patients enrolled, 41 patients (26.6%) had PMV. Patients with PMV showed higher Acute Physiology and Chronic Health Evaluation II scores, lower serum albumin levels, and more AKI on mechanical ventilation (MV) initiation day compared with the non-PMV patients. Patients with PMV were significantly associated with longer MV duration before the day of readiness for weaning (DRW) and a higher rapid shallow breathing index on DRW. In a multivariate regression analysis, the independent risk factors for PMV were AKI on MV initiation day (odds ratio [OR], 5.630; 95% confidence interval [CI], 1.378-22.994; P = .016), longer MV duration before DRW (OR, 1.289; 95% CI, 1.158-1.435; P < .001), and higher rapid shallow breathing index on DRW (OR, 1.012; 95% CI, 1.003-1.021; P = .010).

CONCLUSIONS

Acute kidney injury on MV initiation day is an independent risk factor for PMV of more than 21 days, which may be helpful for clinicians to refine their management of these ICU patients early.