Abstract 203

Background: Cardiopulmonary bypass (CPB) in children with congenital heart disease is associated with significant morbidity increased in patients with CLS, associated with complement and contact activation.

Subjects, Measurements: Influence of clinical parameters and serological measurements of complement and contact system and C1-Inh concentration and -activation were prospectively evaluated in 37 infants undergoing surgery with CPB to find out what are the main predictors for CLS. In 10 infants 500 IE C1-Inh (Berinert®) was given immediately after surgery. 5 serial blood samples were collected from the begin of surgery up to 48 h later.

Results: All 37 infants showed complement and contact activation, 12 developed postoperative CLS. Levels of C5a, C1q, C3c were elevated in the CLS group. Younger age and longer bypasstime had a strong correlation to CLS. C1-Inh concentration and -activation is lower in the CLS-group (p<.003). In the substitution group we found sign. higher levels of C1-Inh concentration and -activation and a decrease of C1q and C3a (p<.05) 24 h after surgery.

Conclusions: Before CLS shows clinical evidence, we observe a decrease of C1-Inh. Early substitution of C1-Inh is an approach promising reduction of CLS.