A Clinical Score for Predicting Successful Weaning from Noninvasive Positive Pressure Ventilation in Emergency Department; a Retrospective Cohort Study

 Noninvasive positive pressure ventilation (NIPPV) is recognized as an efficient treatment for patients with acute respiratory failure (ARF) in emergency department (ED). This study aimed to develop a scoring system for predicting successful weaning from NIPPV in patients with ARF.

 In this retrospective cohort study patients with ARF who received NIPPV in the ED of Ramathibodi Hospital, Thailand, between January 2020 and March 2022 were evaluated. Factors associated with weaning from NIPPV were recorded and compared between cases with and without successful weaning from NIPPV. Multivariable logistic regression analysis was used to develop a predictive model for weaning from NIPPV in ED.

 A total of 494 eligible patients were treated with NIPPV of whom 203(41.1%) were successfully weaned during the study period. Based on the multivariate analysis the successful NIPPV weaning (SNOW) score was designed with six factors before discontinuation: respiratory rate, heart rate ≤ 100 bpm, systolic blood pressure ≥ 100 mmHg, arterial pH≥ 7.35, arterial PaCO2, and arterial lactate. The scores were classified into three groups: low, moderate, and high. A score of >14.5 points suggested a high probability of successful weaning from NIPPV with a positive likelihood ratio of 3.58 (95%CI: 2.56-4.99; p < 0.001). The area under the receiver operating characteristic (ROC) curve of the model in predicting successful weaning was 0.79 (95% confidence interval (CI): 0.75-0.83).

 It seems that the SNOW score could be considered as a helpful tool for predicting successful weaning from NIPPV in ED patients with ARF. A high predictive score, particularly one that exceeds 14.5, strongly suggests a high likelihood of successful weaning from NIPPV.