蛇咬傷使用加壓固定的條件

SNAKE BITE

急診教科書 TINTINALLI'S EMERGENCY MEDICINE 第八版建議. 可使用 CONSTRICTION BAND 不要使用止血帶. 原則是不可阻斷動脈血流. 但要做到安全有效的打上 CONSTRICTION BAND 需要練習. 如果對於這項技術不熟悉, 不如不要做. 毒蛇咬傷最佳治療仍然是施打抗毒血清, 其他方式都僅限於輔助. 對預後差異不大.
不要做一些有害的治療也很重要. 

http://www.uptodate.com/contents/snakebites-worldwide-management

麻痺性蛇毒(神經性)如果不會造成局部組織破壞, 病患需要很長時間才能轉送到醫療院所, 可使用彈性繃帶加壓固定

如果蛇毒會造成局部組織顯著壞死(出血性蛇毒), 不建議加壓固定, 在這種狀況, 蛇毒侷限在固定部位, 會造成該部位組織嚴重破壞, 增加腔室壓力 (會引起腔室症候群), （眼鏡蛇科或不明種類毒蛇咬傷不建議用彈性繃帶）

Pressure immobilization — We suggest that patients with snakebites from species with venoms that cause paralysis with little to no local tissue damage (eg, Australian elapids, kraits, some purely neurotoxic cobras, coral snakes, or South American rattlesnakes) and for whom transportation to definitive medical treatment will be prolonged receive pressure immobilization rather than immobilization alone. Pressure immobilization is not suggested following bites by snake species whose venom is associated with significant local tissue necrosis (eg, many cobras, adders, pit vipers, and rattle snakes). In these patients, localization of toxin may worsen tissue damage and could possibly raise compartment pressures.

彈性繃帶加壓固定方式

1. 不要移除衣物

2. 減少過度移動受傷肢體

3. 讓病患休息, 受傷部位低於心臟,. 使用彈性繃帶纏繞受傷肢體. 從遠端往近端纏繞

4. 如果沒有彈性繃帶, 可以將褲襪或衣服摺成帶狀使用

5. 確定纏繞牢固, 寬鬆度跟固定腳踝類似, 要容許兩根指頭可以伸進去, 不影響遠端脈搏

6. 使用各種器具做固定, 木板, 樹枝, 報紙, 睡袋 睡墊, 背架, 上肢固定之後可以使用手臂吊帶

7. 到醫院前不要移除彈性繃帶, 除非繃帶綁太緊, 影響血液循環, 如果要超過八小時以上才能到醫院, 可以適度放鬆壓力. (但又要小心不要造成蛇毒散播到全身.. 好難啊) 

Application of a pressure immobilization bandage to the extremity consists of the following steps (figure 2) [6]:

●Do not remove clothing. 

●Avoid excessive movement of the affected limb. 

●With the patient at rest and the affected extremity below the heart, wrap the extremity with an elastic bandage from the lower to the upper portion of the limb. 

●If an elastic bandage is not available, use pantyhose or other clothing torn into wide strips. 

●Ensure that the bandage is firm and has the same tightness as for wrapping of a sprained ankle but permits passage of two fingers underneath. Check that distal pulses remain palpable. 

●Fashion a splint out of any rigid object (eg, padded piece of wood or tree branch, rolled newspaper, sleeping bag pad, or backpack frame) and apply to the extremity as follows: 

•Splint the leg posteriorly in extension immobilizing the ankle and the knee. 

•Splint the arm to the elbow and apply a sling. 

●Do not remove the pressure immobilization bandage until the patient has reached the hospital and a clinical assessment regarding the need for antivenom has occurred. 

One exception to this rule occurs if it is evident that the bandage is so tight that it is hampering circulation (ie, distal pulses are markedly decreased or not palpable). This situation may occur if pressure immobilization is improperly applied or local swelling has increased the tightness of the bandage. If time to definitive care will exceed the likely ability of the distal limb to survive prolonged anoxia (ie, more than eight hours), the bandage should be carefully loosened to permit distal circulation but to avoid systemic venom absorption.

澳洲的毒蛇咬傷比較常有神經性症狀, 出血造成組織壞死的機會低, 通常需要轉送到醫院的時間需要很長, 所以加壓受傷部位在澳洲被廣泛應用. 在猴子的試驗證實, 加壓至 55 mmHg 可以顯著減少全身性毒性, 在人類的個案報告也顯示可以減緩人體的全身性吸收達 6 小時, 但在人體仍缺乏明確證據顯示加壓能改善預後

使用加壓固定是否有好處, 主要考量是操作者技術是否純熟適當, 澳洲研究顯示蛇咬傷之後只有 30-70% 傷患接受加壓固定, 此外, 加壓到適當壓力的比例在整個過程只有 25%-50% 時間有達到.

The pressure immobilization technique has wide support in Australia, where elapid toxin primarily causes neurotoxicity and/or coagulopathy without tissue necrosis and where there may be significant delays in transfer to medical facilities [4,7].

Its potential efficacy was first demonstrated in studies on monkeys using tiger snake venom (Notechis scutatus) with high systemic toxicity [8]. Immobilization of the envenomed limb and application of pressure of approximately 55 mmHg resulted in a significant delay in systemic absorption of venom. Dramatic benefits have also been described with delays of up to six hours for systemic absorption of venom in human case reports [9,10]. However, definitive evidence that pressure immobilization improves the outcomes of snakebites in humans is lacking [4,7].

Proper technique is a major consideration when assessing the potential benefit of pressure immobilization. Case series indicate that only 30 to 70 percent of patients treated for snakebite in Australia have pressure immobilization applied despite heavy emphasis on its use in this region [11,12]. In addition, studies that evaluated intensive training of lay volunteers and healthcare providers indicate that proper bandage pressures are only achieved about 25 to 50 percent of the time [13,14].

Nevertheless, when used correctly for bites by snake species that do not cause local tissue damage, pressure immobilization is unlikely to be harmful and may be helpful.

出血性毒蛇咬傷, 不建議使用彈性繃帶纏繞, 因為組織加壓過度可能造成缺血(類似腔室症候群). 每個地區常見的毒蛇咬傷種類不同. 彈性繃帶纏繞主要來自於神經性毒的動物研究, 所以是否將彈性繃帶纏繞變成世界通用的指引, 其實很有問題.

https://www.ncbi.nlm.nih.gov/pubmed/22065371

J Med Toxicol. 2011 Dec;7(4):324-6. doi: 10.1007/s13181-011-0188-9.
Commentary: pressure bandaging for North American snake bite? No!
Seifert SA1, White J, Currie BJ.

AbstractThis issue of The Journal of Medical Toxicology includes a position statement regarding the use of pressure immobilization for the pre-hospital treatment of North American Crotalinae envenomation. This commentary discusses the background behind the creation of the position statement and explores the issues involved in applying science to real-world public health recommendations and practice.
Comment on
Pressure immobilization after North American Crotalinae snake envenomation. 

[J Med Toxicol. 2011]
PMID: 22065371 PMCID: PMC3550186 DOI: 10.1007/s13181-011-0188-9

2010 ACLS 關於蛇咬傷的建議, 使用一定的壓力捲繞受傷肢體, 但這是美國版的, 台灣未必適用