Respiratory muscle assessment in predicting extubation outcome in patients with stroke

Acute Respiratory Failure in Severe Acute Brain Injury

Acute respiratory failure is commonly encountered in severe acute brain injury due to a multitude of factors related to the sequelae of the primary injury. The interaction between pulmonary and neurologic systems in this population is complex, often with competing priorities. Many treatment modalities for acute respiratory failure can result in deleterious effects on cerebral physiology, and secondary brain injury due to elevations in intracranial pressure or impaired cerebral perfusion. High-quality literature is lacking to guide clinical decision-making in this population, and deliberate considerations of individual patient factors must be considered to optimize each patient's care.

Accuracy of respiratory muscle assessments to predict weaning outcomes: a systematic review and comparative meta-analysis

BACKGROUND

Several bedside assessments are used to evaluate respiratory muscle function and to predict weaning from mechanical ventilation in patients on the intensive care unit. It remains unclear which assessments perform best in predicting weaning success. The primary aim of this systematic review and meta-analysis was to summarize and compare the accuracy of the following assessments to predict weaning success: maximal inspiratory (PImax) and expiratory pressures, diaphragm thickening fraction and excursion (DTF and DE), end-expiratory (Tdiee) and end-inspiratory (Tdiei) diaphragm thickness, airway occlusion pressure (P0.1), electrical activity of respiratory muscles, and volitional and non-volitional assessments of transdiaphragmatic and airway opening pressures.

METHODS

Medline (via Pubmed), EMBASE, Web of Science, Cochrane Library and CINAHL were comprehensively searched from inception to 04/05/2023. Studies including adult mechanically ventilated patients reporting data on predictive accuracy were included. Hierarchical summary receiver operating characteristic (HSROC) models were used to estimate the SROC curves of each assessment method. Meta-regression was used to compare SROC curves. Sensitivity analyses were conducted by excluding studies with high risk of bias, as assessed with QUADAS-2. Direct comparisons were performed using studies comparing each pair of assessments within the same sample of patients.

RESULTS

Ninety-four studies were identified of which 88 studies (n = 6296) reporting on either PImax, DTF, DE, Tdiee, Tdiei and P0.1 were included in the meta-analyses. The sensitivity to predict weaning success was 63% (95% CI 47-77%) for PImax, 75% (95% CI 67-82%) for DE, 77% (95% CI 61-87%) for DTF, 74% (95% CI 40-93%) for P0.1, 69% (95% CI 13-97%) for Tdiei, 37% (95% CI 13-70%) for Tdiee, at fixed 80% specificity. Accuracy of DE and DTF to predict weaning success was significantly higher when compared to PImax (p = 0.04 and p < 0.01, respectively). Sensitivity and direct comparisons analyses showed that the accuracy of DTF to predict weaning success was significantly higher when compared to DE (p < 0.01).

CONCLUSIONS

DTF and DE are superior to PImax and DTF seems to have the highest accuracy among all included respiratory muscle assessments for predicting weaning success. Further studies aiming at identifying the optimal threshold of DTF to predict weaning success are warranted.

TRIAL REGISTRATION

PROSPERO CRD42020209295, October 15, 2020.

Prognostic Factors Associated With Extubation Failure in Acutely Brain-Injured Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

Extubation failure in brain-injured patients is associated with increased morbidity. Our objective was to systematically review prognostic factors associated with extubation failure in acutely brain-injured adult patients receiving invasive ventilation in an ICU.

DATA SOURCES

MEDLINE, Embase, and Cochrane Central were searched from inception to January 31, 2022.

STUDY SELECTION

Two reviewers independently screened citations and selected English-language cohort studies and randomized trials examining the association of prognostic factors with extubation failure. Studies were considered if they included greater than or equal to 80% adult patients with acute brain injury admitted to the ICU and mechanically ventilated for greater than or equal to 24 hours.

DATA EXTRACTION

Two reviewers extracted data on population, prognostic factors, extubation outcomes, and risk of bias (using the quality in prognostic factors tool).

DATA SYNTHESIS

In the primary analysis, adjusted odds ratios (aOR) for each prognostic factor were pooled using random-effects models. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. The search identified 7,626 citations, of which 21 studies met selection criteria. Moderate-certainty evidence suggested increased risk of extubation failure with older age (aOR, 3.0 for upper vs lower tertile; 95% CI, 1.78-5.07) and longer duration of mechanical ventilation (aOR, 3.47 for upper vs lower tertile; 95% CI, 1.68-7.19). Presence of cough (aOR, 0.40; 95% CI, 0.28-0.57) and intact swallow (aOR, 0.34; 95% CI, 0.21-0.54) probably decreased risk of extubation failure (moderate certainty). Associations of other factors with extubation failure were informed by low or very low certainty evidence.

CONCLUSIONS

Patient age, duration of mechanical ventilation, and airway reflexes were associated with extubation failure in brain-injured patients with moderate certainty. Future studies are needed to determine the optimal application of these variables in clinical practice.

Predictors of extubation failure in neurocritical patients: A systematic review

OBJECTIVE

The objective of this study was to identify predictors of extubation failure in neurocritical patients.

METHODS

This was systematic review performed through a bibliographic search of the databases PubMed/Medline, Lilacs, SciELO, and Web of Science, from February 2020 to October 2021. Cohort studies that investigated the predictors of extubation failure were included, defined as the need for reintubation within 48 h after extubation, in adult neurocritical patients. The risk-of-bias assessment was performed using the Newcastle-Ottawa Scale, for cohort studies.

RESULTS

Eight studies, totaling 18 487 participants, were included. A total of 15 predictors for extubation failure in neurocritical patients have been identified. Of these, four were the most frequent: low score on the Glasgow Coma Scale (motor score ≤5, 8T-10T), female gender, time on mechanical ventilation (≥7 days, ≥ 10 days), and moderate or large secretion volume.

CONCLUSIONS

In addition to the conventional parameters of weaning and extubation, other factors, such as a low score on the Glasgow Coma Scale, female gender, mechanical ventilation time, and moderate or large secretion volume, must be taken into account to prevent extubation failure in neurocritical patients in clinical practice.

Development and Validation of a Machine-Learning Model for Prediction of Extubation Failure in Intensive Care Units

Background: Extubation failure (EF) can lead to an increased chance of ventilator-associated pneumonia, longer hospital stays, and a higher mortality rate. This study aimed to develop and validate an accurate machine-learning model to predict EF in intensive care units (ICUs). Methods: Patients who underwent extubation in the Medical Information Mart for Intensive Care (MIMIC)-IV database were included. EF was defined as the need for ventilatory support (non-invasive ventilation or reintubation) or death within 48 h following extubation. A machine-learning model called Categorical Boosting (CatBoost) was developed based on 89 clinical and laboratory variables. SHapley Additive exPlanations (SHAP) values were calculated to evaluate feature importance and the recursive feature elimination (RFE) algorithm was used to select key features. Hyperparameter optimization was conducted using an automated machine-learning toolkit (Neural Network Intelligence). The final model was trained based on key features and compared with 10 other models. The model was then prospectively validated in patients enrolled in the Cardiac Surgical ICU of Zhongshan Hospital, Fudan University. In addition, a web-based tool was developed to help clinicians use our model. Results: Of 16,189 patients included in the MIMIC-IV cohort, 2,756 (17.0%) had EF. Nineteen key features were selected using the RFE algorithm, including age, body mass index, stroke, heart rate, respiratory rate, mean arterial pressure, peripheral oxygen saturation, temperature, pH, central venous pressure, tidal volume, positive end-expiratory pressure, mean airway pressure, pressure support ventilation (PSV) level, mechanical ventilation (MV) durations, spontaneous breathing trial success times, urine output, crystalloid amount, and antibiotic types. After hyperparameter optimization, our model had the greatest area under the receiver operating characteristic (AUROC: 0.835) in internal validation. Significant differences in mortality, reintubation rates, and NIV rates were shown between patients with a high predicted risk and those with a low predicted risk. In the prospective validation, the superiority of our model was also observed (AUROC: 0.803). According to the SHAP values, MV duration and PSV level were the most important features for prediction. Conclusions: In conclusion, this study developed and prospectively validated a CatBoost model, which better predicted EF in ICUs than other models.

Predictors of Extubation Success in Patients with Posterior Fossa Strokes

OBJECTIVE

Posterior fossa stroke is unique in its presentation and outcomes, and mechanical ventilation is commonly used in the management of these patients. We aimed to identify predictors of extubation success in patients with posterior fossa stroke, who require mechanical ventilation.

DESIGN

We included consecutive adult patients admitted to the neurosciences ICU from January 2003 to December 2012. Extubation failure was defined as re-intubation within 7 days of extubation. A modified Rankin Scale score of 0-3 was considered a good outcome.

MEASUREMENTS AND MAIN RESULTS

We identified 150 patients with mean age of 65 ± 15.7 years with posterior fossa strokes; 77 (51 %) were hemorrhagic, and 73 (49 %) were ischemic. The most common reason for intubation was depressed consciousness (54 %). Fifty-two (35 %) were successfully extubated, 18 (12 %) failed extubation, 17 (11 %) patients had tracheostomy without attempted extubation, and 63 (42 %) were transitioned to palliative care prior to extubation. In the logistic regression analysis, controlling for transition to palliative care, Glasgow Coma Score (GCS) score >6 at the time of intubation (p = 0.020), mechanical ventilation for less than 7 days (p = 0.004), and surgical evacuation of a hematoma (p = 0.058) were independently associated with successful extubation. The presence of cough, gag reflex, and absence of pneumonia/atelectasis were not associated with successful extubation. Success of extubation predicted a good outcome at hospital discharge.

CONCLUSIONS

In posterior fossa stroke patients with a GCS ≤ 6 at the time of intubation and who remain intubated for more than 1 week, extubation is less likely to be successful, and tracheostomy should be considered.

Efficacy of pulmonary rehabilitation using cervical range of motion exercise in stroke patients with tracheostomy tubes

[Purpose] In this study, stroke patients who were intubated with tracheostomy tubes performed cervical range of motion exercises, and changes in their pulmonary and coughing functions were examined. [Subjects and Methods] Twelve stroke patients who were intubated with tracheostomy tubes participated in the study. The subjects were randomly assigned to either the control group (n=6), which did not perform cervical range of motion exercises, or the experimental group (n=6), which did perform exercises. [Results] With regards to forced vital capacity, forced expiratory volume at one second, and peak cough flow rate before and after the exercises, the control group did not show any significant differences while the experimental group showed statistically significant increases in all three parameters. [Conclusion] The results indicate that cervical range of motion exercises can effectively improve the pulmonary function and coughing ability of stroke patients intubated with tracheostomy tubes, and that cervical range of motion exercises can help in the removal of tracheostomy tubes.

Predictors of extubation failure in neurocritical patients identified by a systematic review and meta-analysis

Background

Prediction of extubation failure, particularly in neurocritical patients, is unique and controversial. We conducted a systematic review and meta-analysis to identify the risk factors for extubation failure in these patients.

Methods

A literature search of databases (MEDLINE, EMBASE, the Cochrane Library, and Web of Science) was performed up to August of 2013 to identify trials that evaluated extubation failure predictors. Included trials were either prospective or retrospective cohort studies.

Results

Nine studies involving 928 participants were included. The systematic review and meta-analysis revealed that the following were predictive for extubation failure: pneumonia, atelectasis, mechanical ventilation of >24 h, a low Glasgow Coma Scale score (7–9T) (OR = 4.96, 95% CI = 1.61–15.26, P = 0.005), the inability to follow commands (OR = 2.07, 95% CI = 1.15–3.71, P = 0.02), especially the command to close the eyes, thick secretion, and no intact gag reflex. Meanwhile, the following were not predictive for extubation failure: sex, secretion volume, coughing upon suctioning, and the inability to follow one command among showing two fingers, wiggling the toes, or coughing on command. Additionally, some traditional weaning parameters were shown to poorly predict extubation failure in neurocritical patients.

Conclusions

Besides pneumonia, atelectasis, and the duration of mechanical ventilation, other factors that should be taken into consideration in the prediction of extubation failure when neurocritical patients are weaned from tracheal intubation include neurologic abilities (Glasgow Coma Scale score and following commands), the secretion texture, and the presence of a gag reflex.