Analysis of patients with hydrogen sulfide poisoning reported to the Taiwan Poison Control Center between 1986 and...

Hydrogen sulfide exposure is a major cause of occupational poisoning and is frequently associated with life-threatening effects. This study aimed to investigate the patterns, poisoning severity, and predictors of severity in patients with hydrogen sulfide poisoning in Taiwan.

This study identified all hydrogen sulfide poisoning cases reported to the Taiwan Poison Control Center between 1986 and 2021. Their medical records were independently reviewed by two trained clinical toxicologists. Categorical variables were assessed using Fisher's exact test, while continuous variables were analyzed using the Mann-Whitney U-test. Multiple variable logistic regression was performed to calculate adjusted odds ratios and 95% confidence intervals for various factors associated with severe-to-fatal outcomes, adjusted for age and sex.

A total of 168 patients were included in the study. Over 70% were exposed occupationally, including those working in the manufacturing industry (41.6%), underground settings (17.9%), and hot spring reservoirs (14.3%). Severe-to-fatal poisoning occurred in 93 patients (46 with severe poisoning and 47 fatalities). Several factors were found to be associated with severe-to-fatal poisoning, including working in confined spaces (adjusted odds ratio = 2.59, P = 0.03), underground workplaces (adjusted odds ratio = 6.60, P = 0.002) and presence of lung infiltrations (adjusted odds ratio = 167.6, P = 0.001). Higher initial pH (adjusted odds ratio = 0.48, P = 0.039) and bicarbonate levels (adjusted odds ratio = 0.79, P = 0.02) were associated with lower odds of severe-to-fatal poisoning. Prompt administration of sodium nitrite before out-of-hospital cardiac arrest was related to a lower odds of death (adjusted odds ratio = 0.43, P = 0.49), though the result did not reach statistical significance.

Hydrogen sulfide poisoning in Taiwan was predominantly occupational and frequently occurred in confined environments, with a high proportion of severe and fatal outcomes. These findings underscore the critical role of environmental conditions and early clinical presentation in determining poisoning severity. While sodium nitrite may have potential therapeutic value, its effectiveness remains uncertain. Further studies are needed to clarify the role of sodium nitrite and optimize management strategies.

Working in confined workplaces or underground environments, initial metabolic acidosis, and pulmonary infiltrates were each associated with a higher odd of a severe-to-fatal hydrogen sulfide poisoning. Early sodium nitrite use before out-of-hospital cardiac arrest might be associated with lower, albeit statistically insignificant, case fatality.