Comparison of standardized diaphragm ultrasound measurement and conventional methods for predicting weaning failure:...

Weaning from invasive mechanical ventilation (IMV) is challenging and has multiple causes. The diaphragm is the main respiratory muscle for inspiration. This prospective study aimed to determine the value of standardized diaphragm ultrasound (DUS) measurements [diaphragm excursion (DE), diaphragm thickness fraction (DTF), diaphragmatic rapid shallow breathing index (D-RSBI), rapid shallow diaphragmatic index (RSDI)] in predicting extubation success in intensive care patients, both individually and in combination with conventional indices [rapid shallow breathing index (RSBI), dynamic compliance (Cdyn), airway occlusion pressure, semi-quantitative cough strength score]. To isolate diaphragm contribution, only neurologically intact patients (Glasgow Coma Scale > 14) with adequate airway protection reflexes were included. The second aim was to examine the relationship between IMV and DUS measurements.

151 patients on IMV for > 24 h and eligible for spontaneous breathing trial (SBT) were evaluated. Following exclusion criteria, patients underwent SBT in pressure support ventilation mode (positive end-expiratory pressure 5 cmH₂O, pressure support 8 cmH₂O). During SBT, mechanical ventilation parameters and diaphragm ultrasound measurements were recorded. Extubation failure was defined as need for reintubation or non-invasive ventilation.

DE and DTF were significantly higher, D-RSBI was lower in patients with successful extubation. There was no difference in RSDI. Multivariate logistic regression was statistically significant, odds ratios (10.018, 1.109, 1.094) were found for DE, DTF, Cdyn, respectively. The only significant correlation between IMV and DUS was DTF-tidal volume (r = - 0.500).

A standardized multiparametric model, combining DUS with conventional indices, provides moderate predictive accuracy for extubation success. Integrating DUS into weaning protocols can improve extubation readiness.