Use of surveillance criteria reduces interstage mortality after the Norwood operation for hypoplastic left heart syndrome

Abstract
While hospital mortality after the Norwood operation for hypoplastic left heart syndrome (HLHS) has decreased steadily, interstage mortality until the superior cavopulmonary anastomosis (SCPA) remains a major concern. Our aim was to institute a home surveillance programme to decrease interstage mortality. We enrolled 45 HLHS patients surviving the Norwood operation into our home surveillance programme and compared them with 97 patients treated before the initiation of the programme and with a third group of 20 patients not discharged between the first- and the second-stage operation. While still in hospital, parents were taught to record weight and fluid intake as well as oxygen saturations with the help of a vital sign monitor. During the last week of the hospital stay, the following criteria had to be met: oxygen saturation >75%, weight gain of at least 20–30 g in 3 days and a maximum weight loss of 30 g in a day. After discharge, these criteria had to be maintained at all times or the parents were supposed to call our hospital. Additionally, an experienced paediatric cardiologist from our centre called the parents at home once a week. Interstage mortality was reduced significantly from 12.4% (12/97) to 2.2% (1/45) (= 0.042). The number of patients, who were not discharged before the SCPA, was significantly higher after the start of the home surveillance programme (12/57 vs. 8/105, = 0.022). After discharge, 14 (31%) infants breached the surveillance criteria. Of these, one patient died and eight patients were operated earlier (SCPA, = 6; shunt replacement, = 2). The remaining five patients could be discharged home after observation. Children in the home surveillance programme were younger [102 (67–299) vs. 152 (77–1372) days, = 0.001] and weighed less (5.09 ± 0.79 vs. 5.75 ± 1.22 kg, = 0.001) at the SCPA compared with the remainder. Early survival after SCPA was not different. The home surveillance programme led to an important decrease in interstage mortality. The adherence to the surveillance criteria before discharge resulted in a larger number of patients receiving inpatient treatment until SCPA. Earlier SCPA in the surveillance group had no negative impact on early survival after SCPA.