Organophosphate poisoning- the mortality determinants: a comparitive cohort study between the survived and succumbed

Shivkumar Gopalakrishnan and Sangeetha Kandasamy

Importance: OP poisoning is a major global health concern. Few research works have focussed on factors determining death.
Objective: We aimed to identify key factors which determine the outcome among OP poisoned patients.
Design: This is a retrospective cohort study comparing age matched OP poisoned patients [Cohort 1(n=100) Fatal outcome versus Cohort 2(n=200) Survived].
Setting and Participants: The study was conducted at Government Villupuram Medical College and Hospital, Southern India. Only moderate and severely Organophosphate poisoned inpatients were included in the study as per Peradeniya OP Scale5. The data were collected under 3 heads- Pre-admission, [in hospital] Clinical features and Management factors.
Exposure: Patients who were exposed to OP within the last 24 hours and with signs of toxicity.
Main Outcomes: The only two outcomes studied were death and survival.
Results:Mortality determining pre admission factors were delayed presentation [22 % of Cohort 1 vs 9.5% of Cohort 2, Chi sq 22.24,p <0.001] and alchohol co ingestion [28% in Cohort 1 vs 7.5% of Cohort 2, Chi sq 22.82, p<0.001]. Clinically, a Glasgow Coma Score of >10/15 comprised about 70% of Cohort 1, but only 28% of Cohort 2[Chi sq 58.18, p<0.001]. Secondly, shock [systolic BP<90mmHg] was prominent in Cohort 1[63%] as compared to Cohort 2[33%], Chi sq 50.926, p<0.001. The Odds Ratio for a fatal outcome in a patient with refractory shock was 6.07, p<0.001. The most significant ECG finding was QTc prolongation [Cohort 1(43%) vs Cohort 2(13%), p<0.001].Management factors revealed that atropinisation was inadequate in the majority of Cohort 1 patients [87%] and only 24% of Cohort 2 patients [Chi sq150.06, p<0.001].Ventilator support was long sustained in Cohort 1[73%] compared to Cohort 2[31%] Chi sq 109.47, p<0.001.
Conclusion: This study identified key factors like delayed presentation, alchohol co ingestion, GCS >10/15, refractory shock, QTc prolongation, need for prolonged ventilation and improper atropinisation influencing the outcome.
Relevance: The information gained from this study enabled us to locate and rectify the lacunae in the effective management of OP poisoned patients at our institute.

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