Role of Bedside Ultrasonography in Assessment of Diaphragm Function as a Predictor of Success of Weaning in Mechanically Ventilated Patients

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

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diaphragm muscle parameters as a predictive tool for weaning critically ill patients from mechanical ventilation: a systematic review and meta-analysis study

Diaphragmatic ultrasound, valued for its portability and safety, assesses both structural and functional aspects of the diaphragm. While some studies support its predictive value, others conflict. This meta-analysis aims to clarify diaphragmatic ultrasound's role in predicting successful liberation from mechanical ventilation in intensive care settings. A systematic search was performed on Web of Science, Scopus, and PubMed up to March, 2024. The search strategy included a combination of relevant medical subject heading (MeSH) terms and relevant keywords. We defined our eligibility criteria based on the PICO framework. Two authors performed the data extraction using a standardized sheet. The pooled mean difference was calculated using random effects model and Hedges' g along with SD estimation. R and RStudio were used for the statistical analysis and creating forest and funnel plots. The pooled mean difference was 7.25 (95% CI: 4.20, 10.21) for DE among the two groups. We found a statistically significant difference between the two groups indicating that those with successful weaning from intubation had higher means of DE compared to those with failed weaning attempt (p-value<0.01). The mean difference of DTF was also higher among those with successful weaning from intubation compared to those with failed weaning attempt with the pooled mean difference of 14.52 (95% CI: 10.51, 18.54, p-value<0.01). The mean difference of RSBI was lower among those with successful weaning from intubation compared to those with failed weaning attempt with the pooled mean difference of -28.86 (95% CI: -41.82, -15.91, p-value<0.01). Our results suggest that evaluating diaphragmatic excursion and thickening fraction can reliably anticipate successful liberation from mechanical ventilation. However, significant heterogeneity was present among the included studies. High-quality research, particularly randomized clinical trials, is required to further elucidate the role of diaphragmatic ultrasound in predicting weaning from mechanical ventilation.

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.

The Role of Ultrasonography in the Process of Weaning from Mechanical Ventilation in Critically Ill Patients

Weaning patients from mechanical ventilation (MV) is a complex process that may result in either success or failure. The use of ultrasound at the bedside to assess organs may help to identify the underlying mechanisms that could lead to weaning failure and enable proactive measures to minimize extubation failure. Moreover, ultrasound could be used to accurately identify pulmonary diseases, which may be responsive to respiratory physiotherapy, as well as monitor the effectiveness of physiotherapists' interventions. This article provides a comprehensive review of the role of ultrasonography during the weaning process in critically ill patients.

Ultrasonography to Access Diaphragm Dysfunction and Predict the Success of Mechanical Ventilation Weaning in Critical Care: A Narrative Review

INTRODUCTION

Weaning failure is common in mechanically ventilated patients, and whether ultrasound (US) can predict weaning outcome remains controversial. This review aims to evaluate the diaphragmatic function measured by US as a predictor of weaning outcome.

METHODS

PubMed was searched to identify original articles about the use of diaphragmatic US in ICU patients. A total of 61 citations were retrieved initially; available data of 26 studies were included in this review.

RESULTS

To assess diaphragmatic dysfunction in adults, six studies evaluated excursion, five evaluated thickening fraction, and both in nine. Despite heterogeneity in the diagnostic accuracy of diaphragm US among the studies, the sonographic indices showed good diagnostic performance for predicting weaning outcome.

CONCLUSIONS

Diaphragmatic US can be a useful and accurate tool to detect diaphragmatic dysfunction in critically ill patients and predict weaning outcome.

Effectiveness of diaphragmatic ultrasound as a predictor of successful weaning from mechanical ventilation: a systematic review and meta-analysis

BACKGROUND

Several measurements have been used to predict the success of weaning from mechanical ventilation; however, their efficacy varies in different studies. In recent years, diaphragmatic ultrasound has been used for this purpose. We conducted a systematic review and meta-analysis to evaluate the effectiveness of diaphragmatic ultrasound in predicting the success of weaning from mechanical ventilation.

METHODS

Two investigators independently searched PUBMED, TRIP, EMBASE, COCHRANE, SCIENCE DIRECT, and LILACS for articles published between January 2016 and July 2022. The methodological quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool; additionally, the certainty of the evidence is evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology. Sensitivity and specificity analysis was performed for diaphragmatic excursion and diaphragmatic thickening fraction; positive and negative likelihood ratios and diagnostic odds ratios (DOR) with their confidence intervals (95% CI) were calculated by random effects analysis, summary receiver operating characteristic curve was estimated. Sources of heterogeneity were explored by subgroup analysis and bivariate meta-regression.

RESULTS

Twenty-six studies were included, of which 19 were included in the meta-analysis (1204 patients). For diaphragmatic excursion, sensitivity was 0.80 (95% CI 0.77-0.83), specificity 0.80 (95% CI 0.75-0.84), area under the summary receiver operating characteristic curve 0.87 and DOR 17.1 (95% CI 10.2-28.6). For the thickening fraction, sensitivity was 0.85 (95% CI 0.82-0.87), specificity 0.75 (95% CI 0.69-0.80), area under the summary receiver operating characteristic curve 0.87 and DOR 17.2 (95% CI 9.16-32.3). There was heterogeneity among the included studies. When performing a subgroup analysis and excluding studies with atypical cutoff values, sensitivity and specificity increased for diaphragmatic thickening fraction; sensitivity increased and specificity decreased for diaphragmatic excursion; when comparing studies using pressure support (PS) versus T-tube, there was no significant difference in sensitivity and specificity; bivariate meta-regression analysis shows that patient position at the time of testing was a factor of heterogeneity in the included studies.

CONCLUSIONS

Measurement of diaphragmatic excursion and diaphragmatic thickening fraction predict the probability of successful weaning from mechanical ventilation with satisfactory diagnostic accuracy; however, significant heterogeneity was evident in the different included studies. Studies of high methodological quality in specific subgroups of patients in intensive care units are needed to evaluate the role of diaphragmatic ultrasound as a predictor of weaning from mechanical ventilation.

Methodological and Clinimetric Evaluation of Inspiratory Respiratory Muscle Ultrasound in the Critical Care Setting: A Systematic Review and Meta-Analysis

OBJECTIVE

Significant variations exist in the use of respiratory muscle ultrasound in intensive care with no society-level consensus on the optimal methodology. This systematic review aims to evaluate, synthesize, and compare the clinimetric properties of different image acquisition and analysis methodologies.

DATA SOURCES

Systematic search of five databases up to November 24, 2021.

STUDY SELECTION

Studies were included if they enrolled at least 50 adult ICU patients, reported respiratory muscle (diaphragm or intercostal) ultrasound measuring either echotexture, muscle thickness, thickening fraction, or excursion, and evaluated at least one clinimetric property. Two independent reviewers assessed titles, abstracts, and full text against eligibility.

DATA EXTRACTION

Study demographics, ultrasound methodologies, and clinimetric data.

DATA SYNTHESIS

Sixty studies, including 5,025 patients, were included with 39 studies contributing to meta-analyses. Most commonly measured was diaphragm thickness (DT) or diaphragm thickening fraction (DTF) using a linear transducer in B-mode, or diaphragm excursion (DE) using a curvilinear transducer in M-mode. There are significant variations in imaging methodology and acquisition across all studies. Inter- and intrarater measurement reliabilities were generally excellent, with the highest reliability reported for DT (ICC, 0.98; 95% CI, 0.94-0.99). Pooled data demonstrated acceptable to excellent accuracy for DT, DTF, and DE to predicting weaning outcome after 48 to 72 hours postextubation (DTF AUC, 0.79; 95% CI, 0.73-0.85). DT imaging was responsive to change over time. Only three eligible studies were available for intercostal muscles. Intercostal thickening fraction was shown to have excellent accuracy of predicting weaning outcome after 48-hour postextubation (AUC, 0.84; 95% CI, 0.78-0.91).

CONCLUSIONS

Diaphragm muscle ultrasound is reliable, valid, and responsive in ICU patients, but significant variation exists in the imaging acquisition and analysis methodologies. Future work should focus on developing standardized protocols for ultrasound imaging and consider further research into the role of intercostal muscle imaging.

Diaphragmatic ultrasound in weaning ventilated patients: a reliable predictor?

Timely weaning of mechanical ventilation is clinically difficult, as both early and late discontinuations are associated with adverse events impeding the patient's favorable course in the critical care unit. Many parameters aid in judging whether the patient is going to be safely extubated; however, some remain deficient. We herein describe diaphragmatic ultrasound as a new modality for this purpose, detailing diaphragm excursion and thickness as means of it.

Factores clínicos asociados a extubación fallida y a estridor laríngeo post-extubación en pacientes adultos con ventilación mecánica invasiva

Introducción. La intubación orotraqueal es un procedimiento que conlleva riesgos como la extubación fallida y el estridor laríngeo, los cuales aumentan el riesgo de morbilidad. Objetivo. Identificar los factores asociados a extubación fallida temprana (≤24 horas) y al desarrollo de estridor laríngeo post-extubación en pacientes adultos con ventilación mecánica invasiva (VMI). Materiales y métodos. Estudio de casos y controles con recolección prospectiva de información realizado en la unidad de cuidados intensivos (UCI) de un hospital de IV nivel de Bogotá, Colombia, entre abril de 2019 y febrero de 2020. Se incluyeron 180 pacientes con VMI ≥24 horas y al menos ≥1 intento de extubación: 30 casos, definidos como pacientes con extubación fallida temprana (≤24 horas a la extubación) y 150 controles. Las diferencias en las variables consideradas entre casos y controles se determinaron mediante las pruebas t de Student y Chi 2 o exacta de Fisher. Además, se realizó un análisis multivariado (modelo de regresión logística no condicional) para determinar los factores asociados con extubación fallida y estridor laríngeo post-extubación, calculando los Odds ratio (OR) con sus respectivos intervalos de confianza al 95% (IC95%). Se consideró un nivel de significancia de p<0.05. Resultados. La extubación fallida temprana y el estridor laríngeo tuvieron una prevalencia de 16.66% (n=30) y 3.89% (n=7), respectivamente. En el análisis multivariado, el antecedente de intubación (OR=4.27, IC95%=1.44-12.66), la presencia de cáncer activo (OR= 2.92, IC95%=1.08-7.90) y ser diagnosticado con neumonía (OR=2.84, IC95%=1.15-6.99) se asociaron significativamente con extubación fallida, mientras que la duración de la VMI (OR=1.53, IC95%=1.18-1.99) y el antecedente de intubación (OR=37.9, IC95%=2.22-650.8), con estridor laríngeo post-extubación. Conclusiones. Con base en los resultados aquí obtenidos, se sugiere considerar factores como antecedente de intubación previa, comorbilidad con cáncer y diagnóstico de neumonía en la estratificación de estos pacientes críticos para aumentar la probabilidad de una extubación exitosa.

Early rehabilitation program and weaning outcomes in critically ill chronic obstructed airway disease patients: a randomized trial

Background

To compare the effectiveness of early rehabilitation program on mechanical ventilated COPD patient in RICU to those using current usual care regarding diaphragm function and weaning outcomes.

Methods

The study was a randomized controlled trial. It included 108 newly admitted COPD patients to RICU, Chest Department, Assiut University Hospital, Egypt, in the period from June 2018 to May 2020. They were divided into two groups: group Ι received the usual care plus pulmonary rehabilitation program, and group II received the usual care alone. The outcomes (MV duration, rates of successful weaning, diaphragm function, and lengths of hospital and ICU stay) were recorded and evaluated. The data was analyzed using Student t-test, Mann–Whitney U-test, Wilcoxon signed-rank test, chi-square (χ2) test or Fisher Exact test, receiver operating characteristics (ROC) curve, and logistic regression analysis.

Results

One-hundred and eight COPD patients were included. Early rehabilitation program for COPD patients in the ICU shortened the duration of their MV, increases the rates of successful weaning and decreases 30-day mortality, and shortened the duration of their ICU and hospital stays, as compared to COPD patients who received usual care.

Conclusions

Management of COPD patients with early rehabilitation program is associated with better outcome with improvement of the quality of life of COPD patients.

Trial registration

Clinical trial.gov: NCT03253380

Suppression of Hypoxia-Inducible Factor 1α by Low-Molecular-Weight Heparin Mitigates Ventilation-Induced Diaphragm Dysfunction in a Murine Endotoxemia Model

Mechanical ventilation (MV) is required to maintain life for patients with sepsis-related acute lung injury but can cause diaphragmatic myotrauma with muscle damage and weakness, known as ventilator-induced diaphragm dysfunction (VIDD). Hypoxia-inducible factor 1α (HIF-1α) plays a crucial role in inducing inflammation and apoptosis. Low-molecular-weight heparin (LMWH) was proven to have anti-inflammatory properties. However, HIF-1α and LMWH affect sepsis-related diaphragm injury has not been investigated. We hypothesized that LMWH would reduce endotoxin-augmented VIDD through HIF-1α. C57BL/6 mice, either wild-type or HIF-1α–deficient, were exposed to MV with or without endotoxemia for 8 h. Enoxaparin (4 mg/kg) was administered subcutaneously 30 min before MV. MV with endotoxemia aggravated VIDD, as demonstrated by increased interleukin-6 and macrophage inflammatory protein-2 levels, oxidative loads, and the expression of HIF-1α, calpain, caspase-3, atrogin-1, muscle ring finger-1, and microtubule-associated protein light chain 3-II. Disorganized myofibrils, disrupted mitochondria, increased numbers of autophagic and apoptotic mediators, substantial apoptosis of diaphragm muscle fibers, and decreased diaphragm function were also observed (p < 0.05). Endotoxin-exacerbated VIDD and myonuclear apoptosis were attenuated by pharmacologic inhibition by LMWH and in HIF-1α–deficient mice (p < 0.05). Our data indicate that enoxaparin reduces endotoxin-augmented MV-induced diaphragmatic injury, partially through HIF-1α pathway inhibition.

Lung Ultrasound as a Monitoring Tool

Lung ultrasound has proven to be useful in detecting pneumothorax, interstitial syndrome, and lung consolidation. It is easily applied at the bedside, in real-time, and free of radiation hazards. Recently, the use of lung ultrasound has moved from a diagnostic tool to a monitoring tool for lung aeration quantification. This article reviewed the use of lung ultrasound in monitoring acute pulmonary edema, acute respiratory distress syndrome, and pneumonia, and how it could be used to monitor changes during the application of mechanical ventilation or other treatments for respiratory failure.