Cholinesterase Level in Erythrocyte or Serum: Which is More Predictive of the Clinical Outcome in Patients with Acute Organophosphate Poisoning?

Background: Acute organophosphate poisoning (AOPP) is related to several clinical complications that may be fatal. The aim of this study was to evaluate the effects of demographic, clinical and laboratory findings on AOPP outcome. Methods: In this retrospective cross-sectional study, medical records of all patients with AOPP admitted to Imam Reza Hospital, Mashhad, Iran, were reviewed from January 2016 to December 2017. Demographic data, clinical presentations, erythrocyte cholinesterase (RBC-ChE) and serum cholinesterase (S-ChE) activities were studied and evaluated in relation to clinical outcome of the patients. Results: A total of 64 patients (37 male, 27 female) were evaluated from whom 6 patients (9.4%) died. Statistically significant relationships were found between the outcome of the patients and RBC-ChE activity (p =0.008), intratracheal intubation (p=0.003), and abnormal blood pressure (p =0.009). Despite the lower mean S-ChE levels in the deceased patients and loss of consciousness in 42.2% (n=27) of patients, there was no statistically significant correlations between these factors and patients’ outcome (p =0.147, p =0.075, respectively). Conclusion: RBC-ChE activity, need for intratracheal intubation, and abnormal blood pressure on admission were important predictive factors in the clinical outcome of AOPP. Although S-ChE activity, level of consciousness, white blood cell count and blood glucose level on admission provide useful information, these data had no prognostic value in patients with AOPP.