<p>Hematotoxic Manifestations and Management of Green Pit Viper Bites in Thailand</p>

Abstract

Introduction: Green pit vipers (GPV) are widely distributed throughout Thailand and are responsible for significant morbidity. The primary objective of this study was to characterize clinical presentations and treatment methods for GPV bites. The secondary objective was to demonstrate the earliest and latest onset of hematotoxicity. Methods: GPV bites reported to the Ramathibodi Poison Center between July 1, 2016, and June 30, 2018, were analyzed. Results: There were 288 GPV cases within the study period. Patients were predominantly male (62.8%), and the median age was 40 years (interquartile range (IQR) 22.8-58). Median time from envenomation to hospital presentation was 1 hour (IQR 0.5-2). Patients were primarily bitten on the finger (27.4%). Most patients reported swelling (90.3%). Necrosis and compartment syndrome occurred in 13 and 9 cases, respectively. Systemic effects occurred in 190 cases (65.9%), with median onset 15 hours (IQR 6-28.3) post-bite. Venous clotting time (VCT) showed the highest percentage of abnormalities. Systemic bleeding occurred in 13 cases (4.5%). Monitoring patients for 24, 48, and 72 hours after bites detected 62.7%, 85.9%, and 96.5% of cases with systemic effects, respectively. In total, 184 patients (62.5%) were treated, sometimes repeatedly, with antivenoms (285 courses, 949 vials). The most common indication was prolonged VCT (144 courses, 50.5%). Recurrent systemic effects after antivenom occurred in 11 cases (6.1% of patients received antivenom). No recurrence presented as systemic bleeding. Adverse reactions to antivenom were reported in 44 courses (15.4% of 285 courses), being anaphylaxis in 19 courses (6.7%). Other treatments included antibiotics (192 cases, 66.7%), surgical intervention (10, 34.7%), and blood components (4, 1.4%). Conclusion: Most GPV bites result in envenomation. The most frequent local effect is mild swelling. Systemic bleeding is uncommon. The current recommendation of a 3-day followup can detect up to 96% of patients who may require antivenom. No severe morbidity or mortality is reported. Antivenoms are primarily indicated by prolonged VCT. Side effects of antivenom are minimal.

Early Adverse Reactions to Snake Antivenom: Poison Center Data Analysis

“…Respiratory symptoms were the second most frequent clinical manifestation of EARs. Both findings are consistent with previous studies of QSMI antivenoms [ 3 , 4 , 5 , 17 , 18 , 43 ]. Severe reactions occurred with an EAR rate of 2.6% and were mainly characterized by hypotension, which is the symptom most often reported in previous studies [ 5 , 11 , 17 , 18 ].…”

“…Epidemiological data reported before 2015 indicated that most venomous bites in Thailand were due to MPV [ 6 ]. However, our findings, in addition to those of studies from 2016 onward, demonstrate a changing trend, with Trimeresurus species or GPV being the most common type [ 3 , 6 ]. A higher risk of snakebites was found in adult males than females, and the peak incidence was in young adults.…”

“…However, there were several differences among the studies, such as the types of snakes implicated, the type and number of antivenoms used, the study design/protocol and study period, in addition to the patient populations. In addition, the main aim of most of these studies [ 3 , 4 , 5 , 22 , 43 , 44 ] was not to determine the frequency of EARs to antivenoms. These differences among the studies might have contributed to the different incidences of EARs reported, including those in our study.…”

“…Snakebite envenomation is the cause of enormous amounts of suffering, disability, and death in many parts of the world [ 1 , 2 ], but the highest number of snakebite victims are reported in sub-Saharan Africa and South and Southeast Asia [ 2 ]. In Thailand, snakebite envenomation is prevalent and is an important medical emergency that causes morbidity and mortality [ 1 , 2 , 3 , 4 , 5 ]. The average annual incidence in Thai people is estimated to be 5035 bites [ 6 ].…”

Coagulopathy After Viper Snakebite in Vietnam and Relationship with Time of Admission

“…In some provinces of Vietnam (eg Lam Dong Province) it is the most frequent cause of snakebite. 9 , 10 Trimeresurus mucrosquamatus has a wide geographic distribution. It causes a serious medical threat to people because of their overlapping habitats with areas of human activities, frequenting human dwellings in pursuit of prey, and inflicting severe envenomation.…”