Proposal for a new mechanism of action for aluminum phosphide (ALP) for causing local injuries in ALP poisoning

Aluminum phosphide (ALP) is a widely used solid fumigant for protecting grains from pests. Its poisoning is commonly encountered in the emergency departments of countries including Iran and India. Many studies are developing new drugs and treatment models to decrease the mortality rate of ALP poisonings in developing nations where effective treatments have limited availabilities. ¹ Metabolic disturbances and their resultant adverse outcomes are believed to originate from direct cellular toxicity caused by toxic gases produced during poisoning (phosphine and diphosphine). Nevertheless, local injuries due to thermal burning are a less described and more rarely reported type of damage from ALP poisoning that may contribute extensively to the mortality and morbidity of patients; however, this phenomenon has been ignored in prognostic evaluations. ^1,2 A study conducted by the author of this letter, Mirakbari, has shown that there are varied settings in which gas ignition has occurred. ² Moreover, he has elucidated on ALP-induced burning and the exothermic and thermal burning effects from solid and gasous agents. ² Thermal injuries ranged from gastrointestinal ulcers and hemorrhages to external dermal burns resulting in death. ² In addition to the effects of the independent variables (Table 1), ^{3 –5} potassium permanganate used in treating ALP poisonings may have played a role in this phenomenon. ^2,6 In most cases, this event occurs internally and is unobservable, providing a reason why combustion injuries are rarely reported despite multiple cases of ALP poisoning. If this is true, it may comprise a new contributing factor for unfavorable outcomes that remain undiagnosed. Further studies are therefore recommended to investigate the basic mechanisms of ALP poisoning to answer the question of whether a subclinical state of detrimental thermal events occurs during these types of poisoning. Here I point out the possible causes of thermal injuries in ALP poisoning based on the current evidence. Table 1 describes the research implications for future studies to document the possible causes of local injuries and to assess possible modifications to treatment strategies that may help prevent these injuries, improving the likelihood of survival for poisoned patients.

Table 1.

Thermal injuries in ALP poisoning and suggested treatment strategy modifications.

Suggested mechanism of occurrence for thermal injuries	References	Hypothesized medical prevention plan or treatment modification
High-concentration flammable gas (phosphine and diphosphine)	3	Attenuating by injecting an inert gas
Hot atmosphere, high temperature	3,4	Hypothermia induction, transferring to cold area
Negative pressure due to suctioning	3,5	Eliminating nasogastric suctioning from available interventionsa
Friction from nasogastric tube	5	Eliminating nasogastric lavage from available interventionsa
Exothermic reaction between potassium permanganate and organic matters	2,6	Elimination of potassium permanganate from treatment plan

ALP: aluminum phosphide.

^aIn both cases, instead of nasogastric lavage and suctioning, gastric ventilation is suggested to insufflate an inert gas into the stomach. ⁷