30. Predictors for prolonged mechanical ventilation in children undergoing cardiac surgery

Abstract

Prolonged mechanical ventilation (PMV) has been associated with deleterious clinical outcomes. Characteristics of the patient and various peri-operative factors can predispose individuals to PMV leading to prolonged hospitalization, increasing costs, morbidity and mortality. We investigated specific predictors of PMV in children who underwent cardiac surgery in a tertiary care centre in Riyadh, Saudi Arabia. Method: Retrospective analysis of 413 pediatric cardiac surgeries performed during a 12 months period. Cases were divided in group-A (MV > 7 days) and group- B (MV < 7 days). Patient demographics, pre-operative, intra-operative and post-cardiac surgery variables including complications were reviewed. Continuous and Categorical variables were compared using Student’s t-test and Chi-square. Univariate and multivariate analyses were performed to identify predictors of PMV. Results: In total, 47 (11.4%) of the 413 children had PMV post-cardiac surgery. Group-A patients were younger [mean age: 7.6 months (SD 17.1) vs 23.4 months (SD 29.3), p < 0.0001], and lighter [mean weight: 4.5 kg (SD 3.7) vs 9.4 kg (SD 6.5), p < 0.0001] than Group-B. The mean duration of mechanical ventilation in Group-A was 21.6 days (SD 16.2) compared to 1.8 days (SD 1.5) in Group-B (p < 0.0001). On univariate analyses, significant predictors of PMV included younger age, low body weight, higher surgical risk category, delayed sternal closure, prolonged bypass and cross-clamp times, higher frequency of acute kidney injury, presence of surgical wound and blood stream infections, pneumonia, and UTI [p < 0.0001 for all analyses]. On multivariate analysis, younger age, low body weight, and higher surgical risk category and delayed sternal closure were significant for PMV. Conclusion: Post-operative infections and delayed sternal closure proved to be the most important factors determining the duration of ventilation. Aggressive efforts to ameliorate infection would facilitate successful early extubation after surgery.