ANAESTH, PAIN & INTENSIVE CARE; VOL 20(4) OCT-DEC 2016 477 CASE REPORT Plasma cholinesterase levels in acute organophosphorus poisoning: a plausible marker for weaning? Jasveer Singh, MD 1 , Dheeraj Kapoor, MD, FCCP, FACEE 1 , Manpreet Singh, MD, FCCP, FACEE, FIMSA 1 , Lakesh K. Anand, MD, FCCP, FIMSA, MAMS 2 1 Associate Professor; 2 Professor Department of Anesthesia and Intensive Care, Govt. Medical College and Hospital, Chandigarh, India. Correspondence: Dr. Dheeraj Kapoor, 1207, Sector 32 B, Chandigarh-160030 (India); Phone: 911724622549, 919646121549; E-mail: kapoor.dheeraj72@gmail.com ABSTRACT Organophosphorus (OP) poisoning is an occupational hazard in developing countries. In addition to cholinergic toxidrome, serial levels of plasma cholinesterase (PCh) are routinely done for making early diagnosis and thereafter predicting the outcome of patients. We observed weaning failure from mechanical ventilation, in a patient with acute OP poisoning on mechanical ventilation, even after attaining standard weaning criteria, probably due to persistently low PCh levels. Patient was successfully weaned only after attaining near-normal levels of PCh. Serial levels of PCh may be incorporated as one of the requisite of extubation criteria beside objective clinical parameters, to reduce morbidity and mortality in this subset of patients. Key words: Organophosphorus, Poisoning; Cholinesterase; Weaning; Extubation; Ventilator Citation: Singh J, Kapoor D, Singh M, Anand LK. Plasma cholinesterase levels in acute organophosphorus poisoning: a plausible marker for weaning? Anaesth Pain & Intensive Care 2016;20(4):477-479 Received: 13 Sep 2016; Reviewed: 16, 20 Sep 2016; Corrected: 22 Sep 2016; Accepted: 2 Oct 2016 INTRODUCTION Organophosphorus (OP) poisoning is a serious occupational hazard in developing countries. Presently, there is an alarming rise of suicidal intake of these compounds with incidence as high as 43.8% in Indian subcontinent. 1 Intoxication by these compounds are usually by inhalational or transdermal route and rarely by parental route. 2,3 In addition to cholinergic toxidrome, serial levels of plasma cholinesterase (PCh) are routinely done for making early diagnosis and thereafter predicting the outcome of patients. 1,4,5 In our ICU, we observed weaning failure in a patient with acute OP poisoning on mechanical ventilation, even after attaining standard weaning criteria. 6 We observed that PCh levels were markedly low initially and during weaning, in this patient. Patient was successfully weaned from ventilator only after attaining near-normal levels of PCh. CASE REPORT A forty years old male presented in emergency room (ER) with altered sensorium and severe respiratory distress. History revealed accidental consumption of some unknown liquid followed by severe headache and 3 episodes of involuntary body movements. He had no other comorbid illness. On examination, pulse rate was 60/minute, blood pressure of 96/68 mmHg, Glasgow Coma Scale (GCS) of 7/15 with quadriparesis and bilateral pinpoint pupils. Patient trachea was intubated by cuffed endotracheal tube; gastric lavage was performed and thereafter immediately shifted to intensive care unit (ICU) for further management. Patient was kept on ventilator support and all routine investigations including