Myocardial Injury in Newborn Infants with Severe Metabolic Acidosis at the First Day of Life

Nam, Seong Woo; Lee, In Hak; Lee, Gui Hee; Choi, Young Ok; Lee, Eun Hee; Shin, Jeong Hee; Choi, Byung Min; Hong, Young Sook; Son, Chang Sung

Abstract

PURPOSE
Severe acidosis by various causes can lead to multi-organ dysfunction including cardiac dysfunction (CD) due to myocardial injury. The aims of this study are to investigate CD in newborn infants with severe acidemia at the first day of life and to evaluate the effect on myocardial injury according to the type and the severity of acidosis.
METHODS
This was a retrospective study of infants > or =34 weeks of gestational age with severe acidemia (pH<7.2) at the first day of life. Infants treated by inotropics due to CD were defined as CD group. To evaluate myocardial injuries, various cardiac enzymes were measured using a commercial kit. RA group (pCO2>60 mmHg) and non-RA group (pCO2< or =60 mmHg) were classified based on the presences of respiratory acidosis. Severe base excess (BE) group (BE<-10) and mild BE group (BE> or =-10) were classified based on the degree of BE.
RESULTS
The levels of CK-MB and myoglobin had significant negative relation with BE. CD group had higher incidences of seizure and mortality and higher levels of CK-MB and cTnI than those of non-CD group. Severe BE group had higher incidences of CD and seizure and higher levels of CK-MB, myoglobin and cTnI than those of mild BE group. Non-RA group had higher levels of CK-MB and myoglobin than those of RA group.
CONCLUSION
At the first day of life, the newborn infants with severe metabolic acidosis have high incidences of CD and myocardial injury. Aggressive monitoring and appropriate treatment for CD according to myocardial injury should be recommended in the newborn infants with severe metabolic acidosis.