Is Serum Creatine Phosphokinase Level Useful to Predict the Severity of Organophosphate Poisoning?

Organophosphate poisoning is a global health burden due to intentional and occupational exposure, particularly in Asian countries. Patients are usually monitored through serum acetylcholinesterase levels. Still, it is non-specific, does not correlate well with the severity of poisoning, and is not widely available in laboratory settings in developing countries. This study aims to assess serum baseline creatine phosphokinase (CPK) levels as a prognostic biomarker in acute organophosphate poisoning.

We recruited all patients older than 12 years who were admitted to the wards of the Indoor Medicine Ward in Burdwan Medical College and Hospital in West Bengal (India) because of ingestion or inhalation of organophosphorus compounds within the previous 12 hours between May 1, 2019, and November 1, 2020. Clinical severity was categorized according to Peradeniya organophosphorus poisoning (POP) scale. Serum CPK, pseudocholinesterase levels, and pH were measured. Levels were reassessed on days three and seven, and patients were followed-up until death or discharge.

100 patients (68 men and 32 women) were included in the study. Most of them presented with miosis (98%), followed by abdominal pain (96%), diarrhea (78%), and vomiting (52%). In the multivariate analysis, the patients with a higher risk of being intubated were younger. Of the analytical levels, the one that showed a better relationship with the risk of intubation was the pseudocholinesterase level, although without statistical significance. Initial CPK levels, time of admission, or stratification on the POP severity scale, offered poor performance after adjustment.

The analytical values of CPK or the POP severity scale at the time the patient presents in the emergency room have limited value to predict the final severity of the picture. The amount of the poison consumed should be collected for future studies to elucidate these differences.