Comparison Between Dead Space/Tidal Volume and Work of Breathing in Predicting Extubation Failure in Critically Ill Children

Abstract

Introduction: It was aimed to compare dead volume-to-tidal volume ratio (VD/VT) with work of breathing (WOBp) in predicting extubation failure in critically ill children undergoing mechanical ventilation treatment in pediatric intensive care unit. Methods: Fourty patients who underwent spontaneous breathing test and planned extubation were divided into two groups as VD/VT and WOBp and were extubated and monitored for 48 hours in the pediatric intensive care unit. Demographic data including age, gender, pediatric risk of mortality III (PRISM III) score, pediatric logistic organ dysfunction (PELOD) score, indication for mechanical ventilation and duration of mechanical ventilation were also evaluated. Results: The median age of the 40 patients was 53 months (27-120) in VD/VT group and 58 months (36-108) in WOBp group (p=0.904). There were no significant differences in PRISM III score, PELOD score, indication for mechanical ventilation, duration of mechanical ventilation and admission diagnoses between the two groups (p=0.862, p=0.342, p=0.742 and p=0.277, respectively). Extubation failure was detected in 3 (15%) patients in VD/VT group and in 5 (25%) patients in WOBp group (p=0.459). The area under the curve with respect to predict extubation failure according to VD/VT was 0.868 (71.5% sensitivity and specificity, p<0.01) and WOBp 0.893 (86% sensitivity and 93.3 specificity, p<0.001). Conclusion: WOBp is a more specific parameter than VD/VT to predict extubation failure in critically ill children with mechanical ventilation treatment. However, there are disadvantages such as difficulty in measurement and of costly catheter.

Keywords

• Dead space
• work of breathing
• extubation success