Congenital heart disease is the most frequent malformation in newborns. The postoperative mortality of these patients can be assessed with the Risk Adjustment in Congenital Heart Surgery-1 (RACHS-1) score. This study evaluates whether the RACHS-1 score can also be used as a predictor for the length of postoperative ventilation and what is the influence of age.

In a retrospective study over the period from 2007 to 2013, all patient records were evaluated: 598 children with congenital heart disease and cardiac surgery were identified and 39 patients have been excluded because of additional comorbidities. For evaluation of mortality, 559 patients could be analysed, after exclusion of 39 deceased patients, 520 cases remained for analysis of postoperative ventilation.

Overall mortality was 7% with a dependency on RACHS-1 categories. The median length of postoperative ventilation rose according to the RACHS-1 categories: RACHS-1 category 1: 9 hours (interquartile range (IQR) 7–13 hours), category 2: 30 hours (IQR 12–85 hours), category 4: 58 hours (IQR 13–135 hours), category 4: 71 hours (IQR 29–165 hours), and category 6: 189 hours (IQR 127–277 hours). Some of the RACHS-1 subgroups differed significantly from the categories, especially the repair of tetralogy of Fallot with a longer ventilation time and strong variability. Younger age was an independent factor for longer postoperative ventilation.

RACHS-1 is a good predictor for the length of postoperative ventilation after cardiac surgery with the exception of some subgroups. Younger age is another independent factor for longer postoperative ventilation. These data provide better insight into ventilation times and allow better planning of operations in terms of available intensive care beds.