Evaluation of Serum Creatine Phosphokinase as a Marker of Severity in Organophosphorus Poisoning

Background & Objectives: Organophosphorus (OP) poisoning is an important global health problem. Estimation of erythrocyte cholinesterase (EChE) and butyrylcholinesterase (BChE) as an evidence of OP poisoning is costly and not regularly performed. There are emerging options for new cheaper biochemical markers in relation to OP poisoning like creatine phosphokinase (CPK). The objectives of this study were to measure serum CPK level and correlate it with severity of poisoning, to evaluate clinical and prognostic significance of CPK in OP poisoning, to assess if serum CPK level can be used as an alternative of BChE level to stratify OP poisoning severity.Method: Total 100 patients of OP poisoning without any prior treatment, presenting within 12 hours, were selected and their clinical severity was categorized according to Peradeniya Organophosphorus Poisoning (POP) scale. Level of serum CPK, blood BChE and pH were measured and total dose of atropine required (mg) until final clinical outcome was calculated.Results: Out of 100, 43% patients had mild, 36% moderate and 21% severe clinical picture. There was a significant positive correlation between serum CPK value and requirement of atropine dose in patient with severe POP scale category and negative correlation with pH and serum cholinesterase levels, indicating that more severe the poisoning more will be serum CPK and requirement of atropine doses while less will be pH and serum cholinesterase, (p<0.0001).Conclusions: This study suggests role of serum creatine kinase as surrogate, relatively cheap and easily quantifiable markers of severe OPC exposure and their association.