Correlation of Serum Cholinesterase Level, Clinical Score at Presentation and Severity of Organophosphorous Poisoning

Abstract

The aim of the study was to correlate between the clinical score described by Peradenya
Organophosphorus Poisoning (POP) scale, serum cholinesterase level at presentation and severity
of poisoning. Consecutive patients of organophosphorous poisoning attending Bir Hospital from
August 2004 to September 2005 were studied.Patients were groupedinto mild, moderate andsevere
poisoning groups according to the POP scale. Fifty patients fulfilled the inclusion criteria. The severity
ofpoisoningdirectlycorrelatedwithserumcholinesteraselevel(P<0.001).Thedifferences inthemean
requirements of atropine on the first day of admission, in the total amount of atropine needed to treat
and in the average duration of hospital stay were significant (P<0.05). There were 26% patients in
moderate poisoning and only 4% patients in severe poisoning, but a total of 14% of the patients died,
indicating that patients with even moderate degree of poisoning had also died. Both the POP scale
severity andderangementinserumcholinesterase levels atinitialpresentationdidnot correlate with
mortality, which could be due to various other co-morbidities and inadvertent stoppage of atropine
infusion particularly at night in the wards. The POP scale and serum cholinesterase at presentation
appeared useful to assess the severity of poisoning, particularly in terms of higher amount of
atropine andprolongeddurationofhospital stay.Thepatients withevidence ofmoderate andsevere
degrees of poisoning need close monitoring. Further studies to evaluate the factors likely to cause
deaths, particularly by closely monitoring of moderate and severe organophosphorous poisoning in
intensive care units, are required to clarify the correlation with mortality.
Key words: organophosphorous poisoning, peradeniya organsophosphorous poisoning scale, serum cholinesterase