Factors associated with intensive care morbidity following surgical repair of tetralogy of fallot

Introduction

The outcome of surgical repair of tetralogy of fallot (TOF) is a useful benchmark for the assessment of congenital cardiac surgical programs. The aim of this study was to describe postoperative morbidity following TOF repair and assess the factors linked to a longer duration of postoperative ventilation.

Methods

Retrospective study of all patients admitted to cardiac intensive care between January 2003 and December 2008 following classic TOF repair. More complex repairs were excluded. Factors were investigated for a relationship with intubation hours using linear regression analysis. Intubation hours were log transformed for the analysis since the data were skewed.

Results

A total of 174 children were included, 97 (56%) male, of whom 31 (18%) had previous palliation with a BT shunt and 23 (13%) had extra medical problems. The median age at repair was 8.9 (range 1.6 to 112.8) months and the median weight was 8.2 (3.5 to 28.5) kg. The median cardiopulmonary bypass (CPB) time was 101 (42 to 292) minutes and 94 (54%) required transannular patch. The median postoperative intubation time was 23 (0 to 566) hours and 11 patients (6%) did not require postoperative ventilation. The median ICU stay was 66 (13 to 791) hours and there was one early death before hospital discharge. One hundred and seventy (95%) patients received an inodilator. Postoperative complications included renal failure and fluid overload requiring peritoneal dialysis (PD) in 31 (17%); junctional ectopic tachycardia (JET) in 29 (16%); other arrhythmias in 10 (6%), delayed chest closure in six (3%) of which two had emergency mediastinal exploration due to bleeding and ECMO in one patient. A multiple regression model for the outcome measure intubation hours indicated that younger age at repair (P = 0.03), associated medical problems (P = 0.04), longer CPB time (P = 0.057), JET, PD, noradrenalin use and adrenaline use (P < 0.01 for all) were independently linked with longer postoperative ventilation times.

Conclusions

Younger children, those with extra medical problems and children that required higher levels of inotropes (probably reflecting low cardiac output syndrome), had longer intubation times. The commonest and most important complications that influenced duration of ventilation were JET and PD. In our series, mortality and length of stay were comparable with other published data.