AB015. How does obesity impair the duration of mechanical ventilation in postoperative cardiac surgery patients?

Background: To investigate whether obesity impairs the duration of mechanical ventilation in postoperative cardiac surgery patients.

Methods: A total of 1,739 patients who underwent elective cardiac surgery procedures under the use of cardiopulmonary bypass from May 2012 to September 2016 were retrospectively analyzed. Body mass index (BMI) was used to classify patients in categories (WHO classification). The total hours of postoperative mechanical ventilation have been correlated with the 3 obesity stages (obese class I, II, III). The non-parametric test of Kruskal-Wallis was used for the statistical analysis Also, obesity in all stages has been correlated with prolonged mechanical ventilation defined as ventilation of more than >24 h by the use of chi-square test

Results: Analysis revealed statistical significant correlation between prolonged ventilation (>24 hours) and all stages of obesity (χ²=8,311, P<0.05). After Kruskal-Wallis analysis between hours of mechanical ventilation and each stage of obesity no correlation was found

Conclusions: Duration in hours of postoperative mechanical ventilation has no correlation with any obesity stage. The incidence of prolonged mechanical ventilation (>24 hours) is higher in obese patients.

Keywords: Mechanical ventilation; obesity; cardiac surgery