Predicting Delayed Ventilator Weaning after Lung Transplantation: The Role of Body Mass Index

Abstract

Background : Weaning from mechanical ventilation is difficult in the intensive care unit (ICU). Many controversial questions remain unanswered concerning the predictors of weaning failure. This study investigates patient characteristics and delayed weaning after lung transplantation.

Methods : This study retrospectively reviewed the medical records of 17 lung transplantation patients from October 2012 to December 2013. Patients able to be weaned from mechanical ventilation within 8 days after surgery were assigned to an early group (n = 9), and the rest of the patients were assigned to the delayed group (n=8). Patients' intraoperative and postoperative characteristics were collected and analyzed, and conventional weaning predictors, including rapid shallow breathing index (RSBI), were also assessed.

Results : The results of the early group showed a significantly shorter ICU stay in addition to a shorter hospitalization overall. Notably, the early group had a higher body mass index (BMI) than the delayed group (20.7 vs. 16.9, p = 0.004). In addition, reopening occurred more frequently in the delayed group (1/9 vs. 5/8, p = 0.05). During spontaneous breathing trials, tidal volume (TV) and arterial oxygen tension were significantly higher in the early group compared to the delayed weaning group, but differences in RSBI and respiratory rate (RR) between groups were not statistically significant.

Conclusions : Low BMI might be associated with delayed ventilator weaning in lung transplantation patients. In addition, instead of the traditional weaning predictors of RSBI and RR, TV might be a better predictor for ventilator weaning after lung transplantation.