The Role of Diaphragmatic Rapid Shallow Breathing Index and Maximum Inspiratory Pressure in Predicting Outcome of Weaning From Mechanical Ventilation

Background Mechanical ventilation is the defining event of intensive care unit (ICU) management. It is a lifesaving intervention in patients with acute respiratory failure and whose spontaneous ventilation is inadequate for subsequent development of life threatening hypoxia and/or respiratory acidosis. Many physicians simply look at the patient’s ability to tolerate a spontaneous breathing trial (SBT) without distress through the respiratory rate (RR) and TV during the SBT. The RR/TV ratio, i.e., the rapid shallow breathing index (RSBI), one of the most used clinical indices to predict weaning outcome, reflects the balance between mechanical load posed on the inspiratory muscles and the inspiratory muscles ability to face it during the weaning attempt. However, RSBI was found to have both variable sensitivity and specificity for predicting weaning outcome. Although the diaphragm plays a fundamental role in generating TV in healthy subjects, if the diaphragmatic efficiency is impaired the accessory inspiratory muscles mild contribute to the ventilation for a limited period of time, for example during a SBT. However, since they are by far less efficient and more fatigable than the diaphragm, their exhaustion was likely lead to weaning failure in subsequent hours. Hence, the contribution of the accessory muscles to TV could compromise the diagnostic accuracy of the RSBI by masking the underlying diaphragmatic dysfunction. Aim of the Work To assess the accuracy of Diaphragmatic Rapid shallow breathing index and Maximum inspiratory pressure in predicting the outcome of weaning from mechanical ventilation. Patients and Methods The study was conducted at Ain Shams University Hospitals over 6 months on Patients who were mechanically ventilated for more than 48 hrs who were ready for weaning. Inclusion Criteria Patients intubated & mechanically ventilated for more than 48 hrs. Patients at their first SBT.Patients with adequate cough reflex. Patients fulfilling criteria of readiness for weaning from mechanical ventilation after resolution of cause of respiratory failure: Patients with score ranging between -1 and +1 on the Richmond Agitation and sedation scale (RASS). Exclusion criteria Age < 18 yrs. Patients with thoracotomy, pneumothorax, or pneumomediastinum. Patients with presence of flail chest or rib fractures. Patients with neuromuscular disease. Use of muscle-paralyzing agents within 48 hours before the study. History or new detection of paralysis or paradoxical movement of a single hemi diaphragm on diaphragmatic ultrasonography. Pregnant females. Unconscious noncooperative patients. Patients with intra-abdominal hypertension, Long term steroid therapy. Results I- Distribution of the studied patients regarding final outcome. II- Demographic data. III. Causes of MV. IV- Days on MV. V- Patients’ data and characteristics before start of weaning trial. VI- SBT Ventilator Breathing pattern after 30 min. VII- Study predictors. Conclusion D-RSBI is a new and promising tool that is superior to the traditional RSBI in predicting weaning outcome also MIP provides appreciated data with greater accuracy to assess inspiratory muscle strength and predicting weaning success in mechanically ventilated patients. Recommendations We could recommend the measurement of MIP and DRSBI as weaning predictors should be an integral part of evaluation of patients plan for weaning from MV. All intensivists should be acquitted with the use of U/S in the evaluation of diaphragmatic function.

Application of bedside ultrasound in predicting the outcome of weaning from mechanical ventilation in elderly patients

Background With the increased ageing of society, more and more elderly people are admitted to the intensive care unit, How to accurately predict whether elderly patients can successfully wean from the ventilator is more complicated. Diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) were measured by bedside ultrasound to assess diaphragm function. The lung ultrasound score (LUS) and the rapid shallow breathing index (RBSI) were used as indices of diaphragm function to predict the outcome of weaning from mechanical ventilation. The aim of this study was to examine the clinical utility of these parameters in predicting extubation success. Methods This prospective study included 101 consecutive elderly patients undergoing a trial of extubation in the ICU of Haidian Hospital between June 2017 and July 2020. Patients were divided into the successful weaning group (n = 69) and the failed weaning group (n = 32). Baseline characteristics, including RSBI, were recorded. Measurements of DE, DTF and LUS were made using ultrasound within 24 h before extubation. Results Median DE was greater in patients with extubation success than in those with extubation failure (1.64 cm vs. 0.78 cm, p = 0.001). Patients with extubation success had a greater DTF than those with extubation failure (49.48% vs. 27.85%, p = 0.001). The areas under the receiver operating curves for the RSBI, LUS, DE and DFT were 0.680, 0.764, 0.831 and 0.881, respectively. The best cut-off values for predicting successful weaning were DTF ≥ 30%, DE ≥ 1.3 cm, LUS ≤ 11, and RSBI ≤ 102. The specificity of DTF (84%) in predicting weaning outcome was higher than that of RBSI (53%), that of LUS (55%), and that of DE (62%). The sensitivity of DTF (94%) was greater than that of RBSI (85%), that of LUS (71%), and that of DE (65%). The combination of RSBI, LUS, DE, and DTF showed the highest AUC (AUC = 0.919), with a sensitivity of 96% and a specificity of 89%. Conclusions DTF has higher sensitivity and specificity for the prediction of successful weaning in elderly patients than the other parameters examined. The combination of RSBI, LUS, DE and DFT performed well in predicting weaning outcome. This has potentially important clinical application and merits further evaluation.

Role of Serum B-type Natriuretic Peptide before and after 2hours of Spontaneous Breathing Trial among Patients under Mechanical Ventilation

Background: Weaning of a patient from mechanical ventilation is very important for the outcomes of the patients. Objective: The purpose of the study was to evaluate the serum level of BNP before and after 2hours of spontaneous breathing trial (SBT) among patients under mechanical ventilation. Methodology: This prospective cohort study was conducted in the Department of Anesthesia, Analgesia and Intensive Care Medicine at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh over a period of 2 years. Study population was selected for weaning from mechanical ventilation support for the first time in the age group of more than 18 years with both sexes. Plasma BNP level of all patients was measured before and after 2 hours of spontaneous breathing trial. Results: A total number of 30 patients were recruited for this study. One-third (33.3%) of the patients failed on SBT. The mean percent changes of BNP (pg/ml) during 2-h of SBT in weaning success and failure groups were 38.41±9.379 and 59.51±2.940 respectively (p=0.01). The receiver-operating characteristic curve analysis for BNP as a predictor of weaning outcome, showed that the area under the curve (AUC) was 0.89. Conclusion: In conclusion BNP is currently a good predictor of different cardiac diseases. Journal of Current and Advance Medical Research, July 2021;8(2):125-129

Explainable Machine Learning to Predict Successful Weaning Among Patients Requiring Prolonged Mechanical Ventilation: A Retrospective Cohort Study in Central Taiwan

Objective: The number of patients requiring prolonged mechanical ventilation (PMV) is increasing worldwide, but the weaning outcome prediction model in these patients is still lacking. We hence aimed to develop an explainable machine learning (ML) model to predict successful weaning in patients requiring PMV using a real-world dataset.Methods: This retrospective study used the electronic medical records of patients admitted to a 12-bed respiratory care center in central Taiwan between 2013 and 2018. We used three ML models, namely, extreme gradient boosting (XGBoost), random forest (RF), and logistic regression (LR), to establish the prediction model. We further illustrated the feature importance categorized by clinical domains and provided visualized interpretation by using SHapley Additive exPlanations (SHAP) as well as local interpretable model-agnostic explanations (LIME).Results: The dataset contained data of 963 patients requiring PMV, and 56.0% (539/963) of them were successfully weaned from mechanical ventilation. The XGBoost model (area under the curve [AUC]: 0.908; 95% confidence interval [CI] 0.864–0.943) and RF model (AUC: 0.888; 95% CI 0.844–0.934) outperformed the LR model (AUC: 0.762; 95% CI 0.687–0.830) in predicting successful weaning in patients requiring PMV. To give the physician an intuitive understanding of the model, we stratified the feature importance by clinical domains. The cumulative feature importance in the ventilation domain, fluid domain, physiology domain, and laboratory data domain was 0.310, 0.201, 0.265, and 0.182, respectively. We further used the SHAP plot and partial dependence plot to illustrate associations between features and the weaning outcome at the feature level. Moreover, we used LIME plots to illustrate the prediction model at the individual level. Additionally, we addressed the weekly performance of the three ML models and found that the accuracy of XGBoost/RF was ~0.7 between weeks 4 and week 7 and slightly declined to 0.6 on weeks 8 and 9.Conclusion: We used an ML approach, mainly XGBoost, SHAP plot, and LIME plot to establish an explainable weaning prediction ML model in patients requiring PMV. We believe these approaches should largely mitigate the concern of the black-box issue of artificial intelligence, and future studies are warranted for the landing of the proposed model.

The predictive value of brain natriuretic peptide or N-terminal pro-brain natriuretic peptide for weaning outcome in mechanical ventilation patients: Evidence from SROC

Objective: Mechanical ventilation is an important treatment for critically ill patients. Physicians generally perform a spontaneous breathing trial (SBT) to determine whether the patients can be weaned from mechanical ventilation, but almost 17% of the patients who pass the SBT still require respiratory support. Cardiac dysfunction is an important cause of weaning failure. The use of brain natriuretic peptide or N-terminal pro-BNP is a simple method to assess cardiac function. We performed a systematic review of investigations of brain natriuretic peptide or N-terminal pro-BNP as predictors of weaning from mechanical ventilation. Data sources: PubMed (1950 to December 2020), Cochrane, and Embase (1974 to December 2020), and some Chinese databases for additional articles (China Biology Medicine (CBM), China Science and Technology Journal Database (CSTJ), and Wanfang Data and China National Knowledge Infrastructure (CNKI)). Study selection: We systematically searched observation studies investigating the predictive value of brain natriuretic peptide or N-terminal pro-brain natriuretic peptide in weaning outcome of patients with mechanical ventilation. Data extraction: Two independent reviewers extracted data. The differences are resolved through consultation. Data synthesis: We included 18 articles with 1416 patients and extracted six index tests with pooled sensitivity and specificity for each index test. For the BNP change rate predicting weaning success, the pooled sensitivity was 89% (83%–94%) and the pooled specificity was 82% (72%–89%) with the highest pooled AUC of 0.9511. Conclusions: The brain natriuretic peptide change rate is a reliable predictor of weaning outcome from mechanical ventilation.

Use of the product of driving pressure and respiratory rate for predicting failure of weaning from mechanical ventilator in medical patients

Background: Respiratory workload increment in the process of mechanical ventilation withdrawal is critical for the determination of weaning outcome. Pressure, tidal volume (Vt) and respiratory rate (RR) are considered as patient’s respiratory power, albeit being affected by excessive respiratory load. We aimed to evaluate the performance of driving pressure (DP)×RR to predict the outcome of weaning.Methods: Plateau pressure (Pplat) and positive end-expiratory pressure tot (PEEPtot) were measured during mechanical ventilation, viz., (1) brief deep sedation, (2) on volume support ventilation of MV with Vt 6 ml/kg and a PEEP of 0 cm H2O, (3) Pplat and PEEPtot were measured by holding breath for 2s after inhalation and exhalation, respectively. The DP was determined as Pplat minus PEEPtot. The highest RR was recorded within 3 min during spontaneous-breathing trial (SBT). Patients that were able to tolerate SBT for 1 h were extubated.Results: Out of the 61 patients studied, 22 failed weaning. During the withdrawal of ventilation, DP×RR was 134.2±33.2 cmH2O·breaths/min and 238.5±61.7 cmH2O·breaths/min (P=0.00), DP was 7.9±1.6 cmH2O and 9.7±2.3 cmH2O (P=0.00), in the “success” and “failure” groups, respectively. The DP×RR index greater than 170 cmH2O·breaths/min had a sensitivity of 95.5% and a specificity of 89.7%, while DP index greater than 8.1 cmH2O had 81.8% sensitivity and 64.1% specificity to predict weaning failure.Conclusions: Measurement of DP×RR during withdrawal of ventilation may help predict weaning outcome. Noticeably, high DP×RR increased the likelihood of weaning failure.

Use of the product of driving pressure and respiratory rate for predicting failure of weaning from mechanical ventilator in medical patients

Background : Respiratory workload increment in the process of mechanical ventilation withdrawal is critical for the determination of weaning outcome. Pressure, tidal volume (Vt) and respiratory rate (RR ) are considered as patient’s respiratory power, albeit being affected by excessive respiratory load. We aimed to evaluate the performance of driving pressure (DP)×RR to predict the outcome of weaning. Methods : Plateau pressure (Pplat) and positive end-expiratory pressure tot (PEEPtot) were measured during mechanical ventilation, viz., (1) brief deep sedation, (2) on volume support ventilation of MV with Vt 6 ml/kg and a PEEP of 0 cm H 2 O, (3) Pplat and PEEPtot were measured by holding breath for 2s after inhalation and exhalation, respectively. The DP was determined as Pplat minus PEEPtot. The highest RR was recorded within 3 min during spontaneous-breathing trial (SBT). Patients that were able to tolerate SBT for 1 h were directly extubated . Results : Out of the 61 patients studied, 22 failed weaning. During the withdrawal of ventilation, DP×RR was 134.2±33.2 cmH 2 O ·breaths/min and 238.5±61.7 cmH 2 O·breaths/min ( P =0.00), DP was 7.9±1.6 cmH 2 O and 9.7±2.3 cmH 2 O ( P =0.00), in the “success” and “failure” groups, respectively. The DP×RR index greater than 170 cmH 2 O·breaths/min had a sensitivity of 95.5% and a specificity of 89.7%, while DP index greater than 8.1 cmH 2 O had 81.8% sensitivity and 64.1% specificity to predict weaning failure. Conclusions : Measurement of DP×RR during withdrawal of ventilation may help predict weaning outcome. Noticeably, high DP×RR increased the likelihood of weaning failure.