After being bitten by a poisonous snake in Korea, many patients experience local pains, edema and systemic complications such as rhabdomyolysis, acute renal failure and neurologic abnormalities, and other complications may occur as well1, 2). Among these complications, coagulapathy results in hemorrhage and in rare cases, infarction and it may lead to death3). Coagulopathy is a clinically common disease; its clinical importance is well known and many case studies of coagulapathy with its associated complications have been conducted. However, its clinical pattern and progress in many cases are determined only by the abnormalities on a blood coagulation test and there are only a few references on its specific clinical characteristics, the evaluation of their seriousness and the length of the follow-up period. Therefore, we examined the clinical characteristics of coagulopathy after 98 patients were bitten by poisonous snakes, and these patients were hospitalized from 1999 to 2006 at the Wonju Christian Hospital, Yonsei University, Wonju College of Medicine.

Coagulopathy caused by poisonous snack bite is a clinically significant complication leading to hemorrhage, infarction and in some cases, fatal diseases. According to Retzios et al,6-8), snake venom forms fibrin by working like thrombin on the fibrinogen molecules. While stable fibrin polymers are made by condensing after eliminating both the fibrinopeptide A and B from the fibrinogen during normal fibrin formation, venom makes the unstable fibrin polymer vulnerable to fibrinolysis and phagocytosis by the reticuloendothelial system by removing only the fibrinopeptide A6, 9). As a result, venom can cause various types of coagulopathy, from simple coagulation abnormalities such as defibrination and isolated thrombocytopenia to serious coagulopathy like DIC, and the prevalence of coagulopathy was reported to be up to 36~50%10). The prevalence of coagulopathy observed in this study (52%) was similar with that in the previous research and the prevalence of DIC (31.6%) was also same as that of other studies (40%)2). Other researchers have shown that the prevalence of coagulopathy and DIC was different according to the types of venoms, and the location and time length of the bite affected the venoms' absorption into the blood. Although the previous studies suggested that serious coagulopathy such as DIC rarely happened because venom was absorbed into the blood in only a small number of cases9), in this study, the prevalence of DIC after poisonous snakebite was not considered to be low.

On comparison of the coagulopathy group and the normal groups to assess the characteristics of coagulopathy that occurred after snake bite, the Hct, protein, albumin, ALP and cholesterol levels of the coagulopathy group were significantly decreased compared to those levels of the normal group, and the cholesterol level of the overt DIC group was lower than that of the non-over DIC group. The decrease of Hct was considered to be caused by the venom's toxicity in blood, and the lower levels of protein, albumin and cholesterol were thought to be due to their leakage and loss outside the blood locally or systemically because of the loss of vessel walls and the increased permeability of the blood vessels due to the venom's cytotoxicity11). Winkler et al.11) reported that the more serious a snakebite was, the lower was the cholesterol level, and the albumin level also tended to decrease with serious snake bite, although the tendency was not statistically significant. The findings of this study that the cholesterol and albumin levels declined after poisonous snakebite in the coagulopathy group and that the cholesterol level was more decreased in the DIC group meant that the degree of coagulopathy was proportionally correlated with the toxicity of venoms and the seriousness of the bite. When the relations between the various clinical symptoms caused by poisonous snake bite and coagulopathy were analyzed statistically, leukocytosis and rhabdomyolysis were meaningfully associated for the coagulopathy group, and hemolysis and rhabdomyolysis were meaningfully associated for the DIC group. One of the characteristic things from this finding was that rhabdomyolysis showed a close correlation with coagulopathy and DIC and this was the same when assessing the risk factors of coagulopathy. The significant variables evaluated on univariate analysis, that is, Hct, protein, albumin, ALP, cholesterol, thrombocytosis, rhabdomyolysis and hemolysis, were analyzed by multivariate logistic regression analysis and rhabdomyolysis was found to be a significant risk factor for coagulopathy following snake bite. When rhabdomyolysis was observed after poisonous snake bite, coagulopathy occurred five times more often in the patients with rhabdomyolysis than that noted in the patients without rhabdomyolysis. The mechanism for rhabdomyolysis's critical role in inducing coagulopathy was thought to be as follows. Rhabdomyolysis extricates many tissue factors of the damaged tissues into the blood and the exposed factors activate the extrinsic pathway of blood coagulation and so this leads to consumption coagulopathy. If this progress is limited, then simple coagulation abnormality happens. Yet when activation of the pathway and consumption coagulopathy happen to a severe degree, then disseminated thrombosis and the following fibrinolysis can occur, along with inducing DIC. The role of rhabdomyolysis in the occurrence of coagulopathy after snake bite was considered to be additional or essential12).

Although the coagulopathy following snakebite improved without specific complications in most cases, its complications were mainly caused by hemorrhage and in rare cases, by infarction13). The period of morbidity of the disease was about 6~7 days, based on the increase of the PT and the consistency of the thrombocytopenia.

As a result, the progress and prognosis of coagulopathy after snake bite is proportional to the seriousness of the bite, so evaluation by interview is important to predict and assess the initial seriousness. Further, the decreased Hct, protein, albumin and cholesterol levels noted on the blood and serum tests are thought to be factors to indirectly examine the seriousness of a snakebite. In particular, as the rhabdomyolysis that follows the bite can indicate a high risk of coagulopathy, the presence of coagulopathy should be checked. When considering the high risk of coagulopathy, if the snakebite is serious and rhabdomyolysis occurs in spite of the normal results of the initial blood coagulation test, then the occurrence of delayed coagulopathy should be examined with performing blood and serum tests 1~2 days after the bite. It should be recognized that coagulopathy following poisonous snakebite can induce various complications that are caused by infarction, as well as that presence of hemorrhage and the treatments and responses should be predicted, evaluated and followed up with considering the morbidity period, which is around 6~7 days.