Severe organophosphate poisoning: how quickly should atropine be administered?
August 15, 2013, 11:22 pm
Comparison of Current Recommended Regimens of Atropinization in Organophophate Poisoning. Connors NJ et al. J Med Toxicol 2013 Jul 31 [Epub ahead of print]
There is a growing consensus among toxicologists that previous recommendations for administering atropine in organophosphate (OP) poisoning were inadequate. Giving a fixed dose of atropine at a fixed interval in some cases would not deliver a full therapeutic dose for an hour or more — occasionally way more.
Since the goal of atropinization is to dry up respiratory secretions and relieve bronchospasm so that the patient can be oxygenated and ventilated, it is reasonable to assume that achieving this goal quickly would improve clinical outcome. Many toxicologists now recommended doubling the previous dose of atropine at fixed intervals, resulting in much more rapid atropinization.
The authors of this paper reviewed current printed and online recommendations for treating OP poisoning, and found that many — but not all — of them reflect the move towards more rapid administration of atropine.Specifically, a major dosing regimen — issued by the World Health Organization (WHO) — would not achieve full atropinization for five or six hours in a severely intoxicated patient. This is unfortunate, since the WHO guidelines are widely available in the developing world, where pesticide poisoning kills upwards of 200,000 patients a year.
The authors state that the “assumption that rapid atropinization improves outcome . . . has not been substantiated.” They do not discuss a recent open-label randomized trial that concluded that rapid incremental dose atropinization decreased morbidity and mortality compared with the standard regimen.
To read my Emergency Medicine News column on rapid atropinization, click here.