Jeevan Dhanarisi1, Fathima Shihana1,2, Kirsi Harju3, Fahim Mohamed1,2,4, Vasundhara Verma5, Seyed Shahmy1,6, Paula Vanninen3, Olli Kostiainen3, Indika Gawarammana1,7, Michael Eddleston1,5. 1. South Asian Clinical Toxicology Research Collaboration, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka. 2. Department of Pharmacology, School of Medical Sciences, University of Sydney, Sydney, Australia. 3. VERIFIN, Finnish Institute for Verification of the Chemical Weapons Convention, Department of Chemistry, University of Helsinki, Helsinki, Finland. 4. Department of Pharmacy, Faculty of Allied Health Sciences, University of Peradeniya, Peradeniya, Sri Lanka. 5. Department of Pharmacology, Toxicology, & Therapeutics, University/BHF Centre for Cardiovascular Science, and Centre for Pesticide Suicide Prevention, University of Edinburgh, Edinburgh, UK. 6. National Science & Technology Commission, Colombo, Sri Lanka. 7. Department of Medicine, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
Abstract
Background: A common manifestation of organophosphorus insecticide self-poisoning is prolonged respiratory failure due to neuromuscular junction dysfunction and likely nicotinic receptor overstimulation. We aimed at collecting preliminary data on whether addition of the competitive nicotinic antagonist rocuronium to standard early therapy might be clinically feasible and associated with reduced duration of ventilation. Methods: A pilot three-arm dose-response phase II trial was set up to compare bolus doses of rocuronium bromide titrated to produce initial >95% or 50% inhibition of neuromuscular function, measured using acceleromyography, plus standard treatment, versus standard treatment alone. After attaining inhibition, patients receiving bolus rocuronium then received rocuronium infusions for a maximum of 120 h. Primary outcome was duration of intubation; secondary outcome was case fatality. Plasma butyrylcholinesterase activity was measured throughout the inpatient stay. Blood was analysed to confirm the organophosphorus insecticide ingested. Results:Forty-five patients were randomised to receive: rocuronium to initially attain 95% inhibition (Roc>95, n = 15), rocuronium to initially attain 50% inhibition (Roc50, n = 14), or no rocuronium (control, n = 16). The most commonly ingested pesticide was profenofos (29/45, 64.4%). Butyrylcholinesterase activity remained severely inhibited for the duration of the study for most patients. Case fatality was 9/45 (20%) and similar across study arms: control 3/16 (18.8%), Roc50 4/14 (28.6%) and Roc>95 2/15 (13.3%) (p = .5842). When excluding patients who died, median [IQR] duration of intubation was significantly longer in the Roc50 (259.5 [176-385] h) and Roc>95 (226.8 [186-355] h) groups compared to controls (88.5 [47-160] h, p = .0162 and p = .0016, respectively).Conclusions: In this pilot dose-response study, we found no evidence that rocuronium in addition to standard therapy reduced the duration of intubation. It is possible that it worsened neuromuscular junction function. Further clinical research, including testing of shorter duration regimens, needs to be performed before nicotinic antagonists can be used in the clinical management of OP poisoning.
RCT Entities:
Background: A common manifestation of organophosphorus insecticide self-poisoning is prolonged respiratory failure due to neuromuscular junction dysfunction and likely nicotinic receptor overstimulation. We aimed at collecting preliminary data on whether addition of the competitive nicotinic antagonist rocuronium to standard early therapy might be clinically feasible and associated with reduced duration of ventilation. Methods: A pilot three-arm dose-response phase II trial was set up to compare bolus doses of rocuronium bromide titrated to produce initial >95% or 50% inhibition of neuromuscular function, measured using acceleromyography, plus standard treatment, versus standard treatment alone. After attaining inhibition, patients receiving bolus rocuronium then received rocuronium infusions for a maximum of 120 h. Primary outcome was duration of intubation; secondary outcome was case fatality. Plasma butyrylcholinesterase activity was measured throughout the inpatient stay. Blood was analysed to confirm the organophosphorus insecticide ingested. Results: Forty-five patients were randomised to receive: rocuronium to initially attain 95% inhibition (Roc>95, n = 15), rocuronium to initially attain 50% inhibition (Roc50, n = 14), or no rocuronium (control, n = 16). The most commonly ingested pesticide was profenofos (29/45, 64.4%). Butyrylcholinesterase activity remained severely inhibited for the duration of the study for most patients. Case fatality was 9/45 (20%) and similar across study arms: control 3/16 (18.8%), Roc50 4/14 (28.6%) and Roc>95 2/15 (13.3%) (p = .5842). When excluding patients who died, median [IQR] duration of intubation was significantly longer in the Roc50 (259.5 [176-385] h) and Roc>95 (226.8 [186-355] h) groups compared to controls (88.5 [47-160] h, p = .0162 and p = .0016, respectively).Conclusions: In this pilot dose-response study, we found no evidence that rocuronium in addition to standard therapy reduced the duration of intubation. It is possible that it worsened neuromuscular junction function. Further clinical research, including testing of shorter duration regimens, needs to be performed before nicotinic antagonists can be used in the clinical management of OP poisoning.
Entities:
Keywords:
Organophosphorus insecticide; duration of ventilation; neuromuscular blocker; pilot clinical study; rocuronium