Summary
Fortyone of 187 infants undergoing corrective surgery for their congenital cardiac
lesions using profound hypothermic circulatory arrest were randomly selected for metabolic
studies. Deep hypothermia of 21 to 22° C core temperature was reached by two different
techniques:
1. Perfusion cooling by extracorporeal circulation (ECC-C)
2. Surface cooling with ice bags combined with perfusion cooling (SC + ECC–C)
After circulatory arrest (34,2 min. ECC-C v.s. 46.7 min. SC + ECC–C) bypass rewarming
was used in both groups. The metabolic reaction to these interventions are described.
No significant differences in acid base status in oxygen consumption, lactate concentration,
serum electrolytes (K+ , Na+ , Ca++ , Cl−) and serum enzyme activity (CPK, alpha-HBDH, LDH, SGOT, SGPT) could be demonstrated
between the two groups of patients during the entire course of cooling, circulatory
arrest and rewarming. The glucose concentration was significantly lower in the ECC-C
group during the entire period of operation. Total cooling time was significantly
shorter in the group without surface cooling. (ECC-C: 12 min, v.s. SC + ECC–C: 64
min). Since no favourable effects of the SC + ECC–C method on systemic metabolism
could be demonstrated and operative results were similar we now prefer the time-saving
ECC-C technique.
Key-Words:
Deep hypothermia - Circulatory arrest - Congenital heart defects - Corrective surgery
- Metabolism
