The impact of the door-to-antivenom time on the resolution of coagulopathy caused by green pit viper bite—a retrospective cohort study

Trimeresurus albolabris (green pit viper) accounts for 95% of human venomous snakebites in Hong Kong and the Green Pit Viper antivenin has become the only antivenom available. Little is known about the impact of early antivenom administration on the duration of venom-induced coagulopathy. This retrospective study aimed to evaluate the impact of the door-to-antivenom time (DTAT) on the duration of such coagulopathy. Consecutive patients with green pit viper bite reported to the Hong Kong Poison Control Centre between 1 January 2012 and 31 December 2022 were included. Electronic medical records were reviewed, and the time and dose of antivenom administration were examined. The level of coagulopathy before and after antivenom was graded using the modified Snakebite Severity Scale. The primary outcome was the duration of venom-induced coagulopathy. Univariate and multivariable generalized linear regression analyses were used to evaluate the association between DTAT and the duration of coagulopathy. In total, 82 adult cases (median age 56 years, 51.2% men) were analyzed. The median DTAT was 4.2 h. DTAT was correlated with the duration of coagulopathy (Spearman r 0.426, p < 0.001), which was correlated with the hospital length of stay (Spearman r 0.357, p = 0.001). However, DTAT was not correlated with the hospital length of stay (Spearman r 0.105, p = 0.346). After adjusting for confounding factors, DTAT (adjusted regression coefficient [β] 1.73, 95% confidence interval [CI] 0.38 to 3.08, p = 0.012), pre-antivenom level of coagulopathy (adjusted β 17.08, 95% CI 3.00 to 31.16, p = 0.017), platelet transfusion (adjusted β 217.11, 95% CI 70.43 to 363.80, p = 0.004), and transfusion of fresh frozen plasma (adjusted β −175.34, 95% CI 330.90 to −19.77, p = 0.027) were significantly associated with the duration of coagulopathy. These findings suggest that prompt administration of antivenom may shorten the duration of coagulopathy.