Pathophysiology of respiratory failure following acute dichlorvos poisoning in a rodent model.
Organophosphate (OP) poisoning causes a cholinergic crisis with a wide range of clinical effects including central apnea, pulmonary bronchoconstriction and secretions, seizures, and muscle weakness. The morbidity and mortality from acute OP poisoning is attributed to respiratory failure but the relative contributions of the central and peripheral effects in producing collapse of the respiratory system are unclear. In this study we used a novel adult rat model of acute OP poisoning to analyze the pathophysiology of acute OP poisoning. We found that poisoning caused rapidly lethal central apnea. In animals sustained with mechanical ventilation, we found that following central apnea there ensued progressive pulmonary insufficiency that was variable in timing and severity. Our findings support the hypothesis that OP poisoning in this animal model causes a sequential "two hit" insult, with rapid central apnea followed by delayed impairment of pulmonary gas exchange with prominent airway secretions.
Gaspari
Romolo J
RJ
Department of Emergency Medicine, University of Massachusetts School of Medicine, 55 Lake Avenue North, Worcester, MA 01655, USA. Gasparir@UMMHC.org
Paydarfar
David
D
D000208:Acute Disease; D000465:Algorithms; D000768:Anesthesia, General; D000769:Anesthesia, Inhalation; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000506:poisoning*; D003627:Data Interpretation, Statistical; D004006:Dichlorvos / Q000506:poisoning*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D010575:Pesticides / Q000506:poisoning*; D011659:Pulmonary Gas Exchange; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial; D012131:Respiratory Insufficiency / Q000139:chemically induced* / Q000503:physiopathology*
D002800:Cholinesterase Inhibitors; D010575:Pesticides; D002245:Carbon Dioxide; D004006:Dichlorvos