手術期間尺神經病變回顧

Perioperative Ulnar Neuropathy: A Review

尺神經是周邊神經中最容易受傷的一條神經，在美國約占麻醉醫學會法律訴訟案件的百分之五，手術期間尺神經病變最容易發生的地方為肘關節cubital tunnel處。不當的麻醉照護和病患姿勢，以及其他的誘發因子：包括先期無症狀尺神經病變（preexisting subclinical ulnar neuropathy），失去保護性反射動作（absence of protective reflexes），糖尿病或其他內科疾病，臂神經叢傷害（branchial plexus injury），長期低血壓等，均會促使尺神經發生缺血現象，在功能上或結構上受到損傷，導致尺神經病變的發生。臨床上可以根據症狀，以及肌電圖和神經傳導方面的檢查來診斷病情，手術期間尺神經病變發生率約為0.04%-0.5克左右。第4和第5手指麻木與疼痛等初始症狀，大多在手術後第二天發生。一年內大約有百分之五十之復原機率，若症狀持續超過一年以上，大多伴隨著疼痛和失能狀態，康復率也呈明顯的降低，尤其是有合併感覺和運動障礙的病患。治療包括手術減壓術、藥物和復健等支持性療法，但效果有限。大多數之專家或學者都承認，對於尺神經病變之因果關係了解有限，也知道事先預防，並不能避免此病發症的發生，但事實上，愈來愈多之證據顯示，在住院的任何時間程，均有發生尺神經病變的可能，因此手術期間尺神經病變有待大家再作進一步之研究，並提出更有效的防範策略。

The ulnar nerve is the single most common site of peripheral nerve injury, constituting 5% of overall ASA closed claims databasae. The ulnar nerve is prone to damage because of its position, particularly in the cubital tunnel at the elbow. Inappropriate anesthetic care and patient malpositioning, and other trigger factors ( such as preexisting subclinical ulnar neuropathy, absence of protective reflex, diabetes mellitus, or other medical disease, injury of branchial plexus and prolonged hypotension )may cause ischemia within ulnar nerve resulting structure or functional damage. Ulnar nerve ischemia may be the most important mechanism for ulnar dysfunction, and perhaps perioperative neuropathy. Clinical features of a peripheral neuropathy, conduction velocity studies and electromyography are helpful diagnostic aids. The incidence of perioperative neuropathy is around 0.04% - 0.5% . Pain, tingling, and numbness in 4th and 5th fingers are the initial symptoms for most neuropathies, and are often noted more than 24h after the operation. Approximately one half of patients who survived the 1st postoperative year, regain completely recovery. Of those with neuropathies persisting for more than 1 year, most have disability from pain or weakness, and the low recovery rate was especially evident in patients with mixed sensory and motor deficits. There is no reliable treatment for ulnar nerve palsy usually, treatment is limited to surgical decompression, medication and physiotherapy. Nonetheless, most authors acknowledge that perioperative ulnar neuropathy remains a clinical entity for which we still have minimal understanding of cause-and-effect relationships, nor whether it is always a preventable complication. Indeed, accumulative evidence suggests ulnar nerve injury can occur at any time during hospitalization, so we should develop a more rigorous understanding of perioperative ulnar nerve injury and a more effective basis for identifying preventive strategies.