Low weight at birth is a risk factor for increased mortality in infants undergoing surgery for congenitally malformed hearts. There has been a trend towards performing surgery in patients early, and for amenable lesions, in a single stage rather than following initial palliative procedures. Our goal was to report on the current incidences of morbidities and mortality in infants born with low weight and undergoing surgery for congenital cardiac disease.

We made a retrospective review of the data from patients meeting our criterions for entry from July, 2000, through July, 2004. The criterions for inclusion were weight at birth less than or equal to 2500 grams, and congenital cardiac malformations requiring surgery during the initial hospitalization. A criterion for exclusion was isolated persistent patency of the arterial duct. We assessed preoperative, intraoperative, and postoperative variables.

We found a total of 105 patients meeting the criterions for inclusion. The median weight at birth was 2130 grams, and median gestational age was 36 weeks. The most common morbidity identified was infections of the blood stream. Infections, and chronic lung disease, were associated with increased length of stay. Survival overall was 76%. Patients with hypoplastic left heart syndrome, or a variant thereof, had the lowest survival, of 62%. The needs for cardiopulmonary resuscitation, or extracorporeal membrane oxygenation, post-operatively were the only factors identified as independent risk factors for mortality.

Patients undergoing surgery during infancy for congenital cardiac disease who are born with low weight have a higher mortality and morbidity than those born with normal weight.

To determine whether the National Nosocomial Infections Surveillance (NNIS) System risk index adequately stratified a population of pediatric patients undergoing cardiac surgery according to the risk of developing surgical site infection (SSI).

A retrospective, case-control study.

An urban tertiary care children's hospital.

Patients who had a median sternotomy performed between January 1,1995, and December 31, 2003, were eligible for inclusion in the study. For all case patients, medical records were reviewed to verify that all patients met the case definition for SSI. Control subjects were chosen randomly from among all patients who underwent median sternotomy during the study period who did not develop SSI.

Thirty-eight patients with SSI and 172 patients without SSI were included. One hundred six patients (50%) were male. The median patient age was 4 months. The sensitivity of the NNIS risk index with cutoff scores of 0 to 1 and 2 to 3 was 20%. The distribution of patients with SSI for an NNIS risk index score of 0 was 0%; for a score of 1, 80%; for a score of 2, 20%; and for a score of 3, 0%. The distribution of patients without SSI for a scores of 0 was 4%; for a score of 1, 87%; for a score of 2, 9%; and for a score of 3, 0%. The area under the receiver-operating characteristic curve (AUC) of the original NNIS risk index was 0.57. The modified risk indices did not perform significantly better, with an AUC range of 0.58 to 0.73.

The NNIS risk index did not adequately stratify pediatric patients undergoing median sternotomy according to their risk of developing an SSI. Various modifications to the risk index yielded only slightly higher AUC values.