Toxicological profile and prognostic factors in phosphide poisoning: insights from a one-year hospital-based study

The primary objective of this study was to compare the mortality rates and clinical severity of aluminum phosphide (AlP) versus zinc phosphide (ZnP) poisoning. The secondary objectives were to identify specific prognostic factors such as method of ingestion and clinical markers (hypotension, acidosis) and to describe the epidemiological profile of these cases in Khorramabad, Iran. A retrospective, cross-sectional study was conducted by reviewing the medical records of 59 patients admitted for AlP or ZnP poisoning to Shahid Rahimi Hospital in Khorramabad during 2021–2022. Data on demographic characteristics, poisoning details, clinical course, and outcomes were collected. Statistical analysis was performed using SPSS version 20, employing descriptive statistics, Chi-square, Fisher’s exact, and independent t-tests. The majority of patients were male (52.5%), with a mean age of 30.12 ± 11.96 years. AlP poisoning accounted for 69.5% of cases, with a significantly higher mortality rate (29.3%) compared to ZnP, which had a single fatality. The method of ingestion was a critical prognostic factor for AlP; patients who consumed it without dissolving it in water had a markedly higher mortality rate (50%) than those who dissolved it first (6.7%). The development of hypotension (P < 0.001) and metabolic acidosis (P = 0.003) within the first 48 h were strongly associated with mortality in AlP poisoning. AlP poisoning accounted for 69.5% of cases, with a significantly higher mortality rate (29.3%) compared to ZnP, which had no fatalities (0%). The method of ingestion was a critical prognostic factor for AlP. Intensive care unit (ICU) admission was also a significant predictor of poor outcome. In contrast, no significant association was found between prognosis and gender, psychiatric history, physical form of the poison, or time to hospital presentation. Aluminum phosphide is significantly more lethal than zinc phosphide, largely due to its form, leading to internal phosphine gas release. The consumption method, along with the development of hypotension and metabolic acidosis, are crucial prognostic indicator for AlP poisoning. These findings underscore the need for aggressive management of metabolic acidosis and hypotension. Stricter enforcement of pesticide sales bans, enhanced safety protocols to prevent accidental exposures, and further research on ZnP poisoning are strongly recommended.