Cardiac injury in organophosphate poisoning after acute ingestion.

INTRODUCTION: Sparse data and conflicting evidence exist on the prevalence and prognosis of organophosphate (OP)-related cardiac toxicity. We aimed to characterize the cardiac abnormalities of OP after an acute cholinergic crisis in adults without previous cardiovascular conditions. PATIENTS AND METHODS: We did a prospective observational study in a tertiary-care hospital of north India (Postgraduate Institute of Medical Education and Research, Chandigarh) in 74 patients aged ≥ 13 years admitted with acute OP poisoning after self-ingestion. A systemic evaluation, including clinical characteristics, electrocardiography, and echocardiography, was performed to estimate the prevalence and prognosis of cardiac injury. A rate-corrected QT interval was calculated using Bazett's method, and >440 milliseconds was used to define prolongation. RESULTS: Chlorpyrifos was the most commonly ingested OP (n = 29). The patients had a similar occurrence of hypotension (n = 10) and hypertension (n = 9) at admission, and electrocardiography demonstrated sinus tachycardia in 38 (51.3%) and sinus bradycardia in one case. During the hospital stay, 3 out of 74 patients had a prolonged rate-corrected QT interval (457, 468, and 461 milliseconds), and one patient developed supraventricular tachycardia. Eight (10.8%) patients developed the intermediate syndrome, and six (8.1%) died. None of the hemodynamic or electrocardiographic abnormalities was associated with in-hospital mortality or intermediate syndrome development on univariant analysis. Baseline echocardiography at hospital discharge was performed in 27 patients (admitted during 2018) and normal in all except mild tricuspid regurgitation in one. At a 6-month follow-up, 23 cases were available for cardiovascular screening (including echocardiography) and had a normal evaluation. CONCLUSION: Cardiac toxicity is uncommon after acute OP self-ingestion and lacks prognostic significance.

Organophosphate induced delayed neuropathy after an acute cholinergic crisis in self-poisoning.

INTRODUCTION: Despite organophosphate pesticide is the most prevalent cause of acute poisoning in low- and middle-income countries, data on organophosphate induced delayed neuropathy (OPIDN) are limited. We aimed to characterize organophosphates' long-term effects on the peripheral nervous system after an acute cholinergic crisis in adults. METHODS: We performed a prospective observational study in an academic hospital of north India in patients aged 13-40 years with acute organophosphate ingestion. After resolving the cholinergic crisis, the patients were followed for six months with neurologic assessments, including history, neurologic examination, and nerve conduction study (NCS). RESULTS: Twenty-three patients were recruited to the study. All but one had normal neurological examination and NCS at discharge from hospital a median duration of six days (interquartile range, 3-10) after self-poisoning. Eight (34.8%) developed OPIDN during the six-month follow-up. Three patients had symptomatic neuropathy, and NCS detected subclinical peripheral nerve involvement in five. All cases were associated with chlorpyrifos ingestion (8/17 total chlorpyrifos cases). Two OPIDN cases had foot drop and gait ataxia at three-month which persist at six-month. One patient had distal paresthesia at three months, which improved at a six-month follow-up. NCS in OPIDN cases invariably revealed axonal degeneration, injury to motor fibers more than sensory fibers, and frequent peroneal nerve involvement. None of the baseline characteristics, including the ingested amount, predicted clinical or subclinical OPIDN in chlorpyrifos self-poisoned patients on a univariant analysis. CONCLUSION: Peripheral nerve involvement is not uncommon after recovery from a cholinergic crisis in chlorpyrifos self-poisoning and debilitating in some patients. Detection of subclinical injury on NCS may provide an early window to prevent severe symptomatic neuropathy.