Incidence and causes of prolonged mechanical ventilation in children with Down syndrome undergoing cardiac surgery

Trisomy 21 is the most common syndrome in children with a 30-50% association with congenital heart disease (CHD). Cardiac surgeries are required in the majority of Down syndrome (DS) with CHD cases. Because of the distinctive abnormalities in their respiratory system, children with DS may require longer positive pressure ventilation after cardiac surgery. The aim of this study is to investigate the incidence and possible risk factors for prolonged mechanical ventilation (PMV) need in DS patients undergoing cardiac surgery.

We conducted a prospective study on all DS children who underwent cardiac surgery from 2013 to 2016. Demographic and perioperative data were collected including the duration of mechanical ventilation, respiratory risk factors such as previous infection, evidence of pulmonary hypertension during the intensive care unit (ICU) stay, the presence of lung collapse, secretion and wheezy chest, inotropes score, sedation score, arrhythmias, and low cardiac output syndrome. Based on the duration of mechanical ventilation, cases were divided into two groups: the control group, comprising of children who required mechanical ventilation for less than 72 hours, and the PMV group, which consisted of children who required mechanical ventilation for 72 hours or more. Risk factors were compared and analyzed between both groups.

A total of 102 participants fulfilled the inclusion criteria, 90 of whom were assigned to the control group and 12 to the PMV group (11.7%). Compared with the control group, the PMV group had a higher incidence of pulmonary hypertension at a younger age (83% vs. 23%, p = 0.012) and 50% of them required chronic treatment for pulmonary hypertension upon home discharge. Pneumonia during ICU stay was encountered more frequently in the PMV group (33.3% vs. 2.2%, p = 0.0042). In addition, the PMV group had more frequent signs of low cardiac output syndrome after surgery (25% vs. 2.2%, p = 0.019), longer ICU stays (7 ± 0.3 days vs. 15.6 ± 2.1 days, p = 0.0001), needed more days of inotropes infusion (7.5 ± 0.4 days vs. 11.1 ± 1.6 days, p = 0.0045), and required more sedative and paralytic agents postoperatively (6 ± 0.6 days vs. 8.7 ± 1 days, p = 0.022).

Overall, 11.7% of DS patients required prolonged ventilation after cardiac surgery. Pulmonary hypertension was seen more frequently in cases requiring PMV, and half of PMV cases required antipulmonary hypertension medication upon discharge. Early recognition of pulmonary hypertension and proper perioperative management are recommended to avoid serious complication and comorbidity after cardiac surgery.