Safety profile of snake antivenom (use) in Hong Kong - a review of 191 cases from 2008 to 2015

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.

The clinical efficacy of Zuqing Xu "Wuduling" powder for snake injury on the swelling of the affected limb bitten by Agkistrodon halys

To determine the clinical efficacy of Zuqing Xu 'Wuduling' powder for snake injury on the swelling of the affected limb bitten by Agkistrodon halys. Sixty-five patients with Agkistrodon halys bite were assigned to a treatment group (n = 35) or control group (n = 30). The treatment group was additionally given 'Wuduling' powder dressing locally based on the therapy to the control group with conventional Western medicine. Clinical efficacy and improvement of traditional Chinese medicine symptoms and signs in the two groups were evaluated. The treatment group showed a notably higher cure rate than the control group. After 3 days of therapy, the swelling and pain of the affected limb in the treatment group were greatly alleviated. Additionally, after 7 days of therapy, the swelling and pain of the affected limb in the treatment group were more greatly alleviated, and those in the control group were also alleviated. The comparison of the two groups during the same period showed more obvious alleviation of swelling and pain in the treatment group than that in the other. Moreover, the treatment group experienced notably shorter disappearing time of swelling and pain than the control group. After treatment, the levels of CRP, TBIL, Cr, ALT, AST, BUN, CK, LDH and CK-MB in both groups declined notably, with notably lower levels of them in the treatment group than those in the other. Zuqing Xu 'Wuduling' powder for snake injury can substantially alleviate the swelling and local pain of affected limbs bitten by Agkistrodon halys.

Venomous snakebites in children: a 10 year experience in South China

INTRODUCTION

Many studies have focused on snakebites in adults, but very few have described snakebites in children.

METHODS

We reviewed the clinical characteristics and outcomes of children with venomous snakebites aged less than 15 years who presented to a regional medical centre in South China from January 2013 to December 2022.

RESULTS

A total of 69 envenomed patients were analyzed in our study; 42 (60.9 per cent) patients were male, and 59 (85.5 per cent) reported lower limb bites. Most bites (89.8 per cent) occurred between April and October. Twenty-seven patients received first aid management, and 47 required admission to the general ward. Antivenom was administered to 58 patients, glucocorticoids to 43 patients, antibiotics to 48 patients, and tetanus antitoxin to 40 patients. No fatalities were reported. The most common snake identified was Trimeresurus albolabris. Four were classified as dry bites, 15 as mild, 43 as moderate, and seven as severe. The most common local signs were pain and swelling, while the most common systemic effects were haematological complications. Patients with high severity scores had significantly higher lactate dehydrogenase activities, creatine kinase isoenzyme activities, aspartate aminotransferase activities, D-dimer concentrations, prothrombin times and lower fibrinogen concentrations. In a receiver operating characteristic curve analysis of the values with the highest Youden index, the following cut-offs proved significant: lactate dehydrogenase activity > 248.1 U/L, creatine kinase isoenzyme activities > 17.5 U/L, fibrinogen concentration < 1,455 mg/L, D-dimer concentration > 437.0 µg/L, aspartate aminotransferase activity > 26.1 U/L, and prothrombin time > 15.2 seconds.

DISCUSSION

This study provides insight into the epidemiology, clinical profile, and management of snakebites in children. Data from the present study were compared with those from our previous adult study. Limitations include that 50.7 per cent of our snakebites were attributed to Trimeresurus albolabris. Therefore, the results of our study may not be generalizable to all snakebites.

CONCLUSION

The clinical symptoms were more severe in children than in adults in our previous study. Even though there were no fatalities, close monitoring should be performed to detect haematological and other potentially fatal complications promptly.

Nationwide and long-term epidemiological research of snakebite envenomation in Taiwan during 2002-2014 based on the use of snake antivenoms: A study utilizing National Health Insurance Database

INTRODUCTION

In Taiwan, six venomous snake species with medical importance have been found; however, long-term epidemiological data of snakebite envenomation (SBE) is lacking. This study aimed to explore the epidemiology of SBE based on the distribution and use of different antivenoms in different parts of Taiwan to facilitate the development of prevention strategies and resource allocation.

METHODS AND RESULTS

This retrospective study was conducted using the Taiwan National Health Insurance Research Database from 2002 to 2014. A total of 12,542 patients were treated with antivenoms. The directly standardized cumulative incidence was 3.6 cases per 100,000 individuals based on the 2000 World Standard Population. The incidence of SBEs peaked in the summer (35.9%). The relative risk (RR) of male patients versus female patients was 2.5 (p < 0.0001). The RRs of patients aged 18-64 and ≥65 years versus those aged <18 years were 6.0 (p < 0.0001) and 14.3 (p < 0.0001), respectively. Furthermore, the RR of eastern Taiwan versus northern Taiwan was 6.8 (p < 0.0001). The RR of agricultural workers versus laborers was 5.5 (p < 0.0001). Compared with patients envenomed by Trimeresurus stejnegeri stejnegeri or Protobothrops mucrosquamatus, those envenomed by Naja atra or Bungarus multicinctus multicinctus were more likely to occur in central (adjusted odds ratio [aOR] = 2.6, p < 0.0001) or southern (aOR = 3.2, p < 0.0001) Taiwan, but less frequently among agricultural workers (aOR = 0.6, p < 0.0001). The overall case-fatality rate was 0.11%.

CONCLUSIONS

Among Asian countries, Taiwan had low incidence and case-fatality rates of SBE. Risk factors included male gender, old age, summer season, being in eastern Taiwan, and being an agricultural worker. Differences of the epidemiological findings between snake species should be focused on when developing strategies for snakebite prevention.

Early Adverse Reactions to Snake Antivenom: Poison Center Data Analysis

Antivenom is an essential treatment for snake envenomation; however, early adverse reactions (EARs) are major limitations to its use. We performed a retrospective cross-sectional study using Ramathibodi Poison Center data (January 2016 to December 2017) to clarify the incidence and severity of EARs following different F(ab’)2 antivenoms. Among 1006 envenomed patients, 684 (68%) received antivenom therapy with a total of 1157 doses, mostly green pit viper antivenom. The overall EAR incidence and rate were 22. 5% (154/684) and 15% (173/1157), respectively. The EAR rate following each type of antivenom was >10%, except for Russell’s viper antivenom (2.9%); the severe reaction rate was 2.6% (30/1157). Malayan pit viper bites caused a high incidence of EARs (37.8%) and the highest EAR rate (22.3%). Fifty-two cases developed anaphylaxis. All EARs occurred within 2 h after treatment initiation. No deaths were attributed to EARs. The duration of administration was significantly different between doses of antivenom that induced EARs and those that did not. In conclusion, all types and every dose of antivenom should be infused for 30−60 min. Preparation of resuscitation equipment and continuous clinical observation are crucial for at least 2 h after administration, and prompt treatment should be provided when EARs occur.

Effect of Agkistrodon halys antivenom in patients bit by green pit viper and the prognostic role of the disease - a retrospective cohort study

BACKGROUND AND AIMS

In Mainland China and Hong Kong, health authorities utilize Agkistrodon halys antivenom in the treatment of patients who sustained bites from green pit vipers. However, the treatment benefit of Agkistrodon halys antivenom among such patients is still controversial. The purpose of this study is to evaluate the coagulation parameters normalization time of Agkistrodon halys antivenom in patients who sustained green pit viper bites and explore independent risk factors of patient prognosis.

METHODS

Data were extracted from the Donghua Hospital Information System. Comparison of the two groups of patients - who used antivenom (GPUA) and who did not use antivenom (GPNUA) were performed using stratified analysis, univariate and multivariate ordered logistic regression models to evaluate the coagulation parameters normalization time. Univariate and multivariate ordered logistic regression models were used to explore independent risk factors of patient prognosis.

RESULTS

Between the GPUA and GPNUA groups, there is no significant difference in the coagulation parameters normalization time with the treatment of Agkistrodon halys antivenom. GPNUA consumed more cryoprecipitate and platelets and had a lower cost. The patient's severity of the bite, first coagulation profile, and dosages of fresh frozen plasma, platelet, and red cell suspension was found to be risk factors for the normalization time of coagulation parameters.

CONCLUSIONS

The therapeutic effect of Agkistrodon halys antivenom in green pit vipers bite patients is not quite satisfying. In addition, more attention should be paid to the first coagulation profile, blood clotting factors indices, platelet count (PLT), and hemoglobin when treating such patients.

A phase IV, prospective, observational study of the clinical safety of snake antivenoms

Snake envenoming is a neglected tropical disease that affects more than 2.7 million people worldwide. The treatment is based on the administration of antivenom composed of heterologous immunoglobulins, species-specific therapy involving the possibility of adverse reactions due to activation of the immune system. Considering the scarcity of prospective studies evaluating the safety of snake antivenoms, this study aimed to describe and characterize adverse events after antivenom infusion in an observational, prospective, single-centre investigation conducted in a referral centre in Brazil. A total of 47 victims of snake envenoming were included in the study, who were mostly men (75%), with ages ranging from 2 to 83 years. Twenty-two participants (47%) presented manifestations compatible with infusion-related reactions (IRRs) during or up to two hours after F(ab')2 heterologous immunoglobulin infusion. The most common clinical manifestation related to the infusion was a diffuse cutaneous rash (82%), followed by respiratory manifestations (46%) and facial swelling (23%). In four cases (9%), IRR were considered serious adverse events (SAE), characterized by haemodynamic instability, airway obstruction or hypoxia. Only one patient developed symptoms compatible with serum sickness. Although almost half of the patients treated with antivenom sera experienced IRRs, the SAE rate was 9%; in all cases, the adverse reaction was reversible by using supportive treatment, and there were no deaths. The results have shown that there is much to improve in the antivenom production process to obtain a more purified and specific product. Even so, a timely antivenom serum administration managed by well-trained health teams is safe and prevents complications after snake-related accidents.

Adverse Reactions after Administration of Antivenom in Korea

Kovax® antivenom is the main treatment for toxins produced by the Gloydius species. However, research on adverse reactions after Kovax® antivenom administration is scarce. We aimed to identify the incidence and characteristics of adverse reactions after Kovax® antivenom administration. We conducted a retrospective review of the medical records of snakebite patients in Korea between January 2008 and September 2019. We identified the frequency, characteristics, and treatments of adverse reactions to Kovax® antivenom. There were 150 patients with snakebites, of whom 121 (80.7%) patients received Kovax® antivenom. Adverse reactions occurred in five patients (4.1%). Acute adverse reactions within 24 h of antivenom administration occurred in two patients (1.7%). The symptoms of patients with acute adverse reactions were nausea, diaphoresis, dizziness, and hypotension. Delayed adverse reactions that occurred 24 h after antivenom administration were reported in three patients (2.5%). One patient had a skin rash after 10 days, and two patients had fever 37 and 48 h after antivenom use. In conclusion, most patients were managed safely after Kovax® antivenom, and the incidence of adverse reactions was low. Severe adverse reactions occurred in a small percentage of patients, and there were no deaths.

Incidence of allergic reactions to Crotalidae polyvalent immune Fab

CONTEXT

The administration of Crotalidae polyvalent immune Fab (FabAV) currently requires close observation, so patients can be monitored for hypersensitivity reactions. The objective of this study was to evaluate the occurrence of hypersensitivity reactions to FabAV.

METHOD

This was a retrospective cohort study utilizing data from a statewide poison center database in the United States. Records of all patients envenomated by a rattlesnake and treated with FabAV between January 2002 and December 2014 were evaluated. Patients with acute hypersensitivity reactions were identified, and reactions were evaluated descriptively.

RESULTS

A total of 1340 adult and pediatric patients received FabAV during the study period. Of these, 19 (1.4%) patients had a potential reaction to FabAV, with 10 requiring a reduction in infusion rate, but none requiring discontinuation of the antivenom. Reactions occurred during the loading dose (n = 10), maintenance doses (n = 4), or were delayed reactions (n = 6). Symptoms recorded included pruritus (n = 8), hives (n = 8), rash (n = 7), vomiting (n = 7), nausea (n = 6), dyspnea or wheezing (n = 4), diaphoresis (n = 3), throat irritation (n = 2), and mild hypotension (n = 2). One patient was given a concomitant administration of low dose epinephrine infusion until completion of the antivenom course. However, none of the reactions were considered to be life-threatening.

CONCLUSION

FabAV appears to be associated with a low incidence of acute hypersensitivity reactions. Patients may not require placement in a location capable of detecting and rapidly responding to hemodynamic and/or airway issues for FabAV monitoring alone.