Objectives:
Role of Creatine Kinase(CK) and Creatine Kinase-Muscle brain fraction(CKMB) in retrospective diagnosis of perinatal asphyxia and their correlation with cardiovascular dysfunction.
Methods:
Cases consisted of 40 asphyxiated full term neonates (>2.0kg) [1min Apgar score <7, requiring assisted ventilation with abnormal neurological examination within first 24 hrs of birth] , subgrouped for severity of asphyxia by levene staging for HIE. [Mild moderate and severe asphyxia as group I II and III respectively] Controls were unasphyxiated healthy neonates. Serum CK and CKMB were determined at 24 hrs of birth.
Results:
Mean Ck and CKMB were significantly higher in controls vs group 2 (826 vs 2949 and 26.2 vs 89.6 respectively, P<.001) and group 3 (826 vs 3475 and 26.2 vs 367.2 respectively P<.001) but not in controls vs group 1 (1107 vs 826 p=0.26 and 35.8 vs 24.4 p=.06). Overall CK was more sensitive than CKMB for retrospective diagnosis of asphyxia (72.5% vs 47.5%) but less specific (60% vs 100%). Cardiovascular dysfunction on echocardiography was seen only in group 2 and group 3 cases [15% and 71.4% respectively]. Presence of cardiovascular dysfunction significantly increased mean CKMB (355 vs 62 P<.001) but not mean CK levels (3108 vs 2276 p =0.25).
Conclusion: Both enzymes are unable to detect mild asphyxia and have low sensitivity for retrospective diagnosis of asphyxia though CKMB is highly specific. CKMB correlates well with both the severity of asphyxia and cardiovascular dysfunction and can be used as a predictor of cardiovascular dysfunction in HIE.