O'Flynn R P, Shutack J G, Rosenberg H, Fletcher J E
Department of Anesthesiology, Hahnemann University, Philadelphia, Pennsylvania 19102.
Anesthesiology. 1994 Jun;80(6):1228-33. doi: 10.1097/00000542-199406000-00009.
Controversy exists regarding the definition of masseter muscle rigidity (MMR) and anesthetic management after MMR. This study reports current anesthetic management after MMR, estimates the incidence of clinical malignant hyperthermia (MH) in patients with MMR, and is the first to evaluate the coincidence of MMR with malignant hyperthermia susceptibility (MHS) according to the 1987 North American Malignant Hyperthermia Group protocol.
Practicing anesthesiologists referred pediatric patients for biopsy between 1986 and 1991 based on evidence of MMR after succinylcholine (1975-1991). The clinical scenario was described as MMR alone or MMR followed by signs of MH, including arterial CO2 tension > 50 mmHg, arterial pH < or = 7.25, and base deficit > 8. Patients had caffeine-halothane muscle contracture testing to determine MHS.
Seventy patients (50 boys and 20 girls) were evaluated. Eighty-three percent (58 of 70) of anesthetics were halothane-succinylcholine. In 68% (48 of 70) of cases, the anesthetic was discontinued, whereas anesthesia was continued with nontriggering agents in 11% (8 of 70) and with triggering agents in 13% (9 of 70). Fifty-nine percent (41 of 70) of patients were diagnosed as MHS by muscle biopsy. In 7% (5 of 70) of patients, clinical MH developed within 10 min of MMR.
This study, by using the current North American Malignant Hyperthermia Group protocol, reaffirms the high incidence (59%, 41 of 70) of MHS associated with MMR as confirmed by muscle biopsy. Of the MHS patients, 5 developed signs of clinical MH. Most anesthesiologists in this study, when confronted with MMR, discontinued anesthesia. Because of the potential lethality of MH and the > 50% concordance between MMR and MHS, the most conservative course of action after MMR is to discontinue the anesthetic and observe the patient for clinical evidence of MH. An acceptable alternative, depending on the urgency of the surgery, would be to continue anesthesia with nontriggering agents for MH, with appropriate monitoring.
关于咬肌强直（MMR）的定义以及MMR后的麻醉管理存在争议。本研究报告了MMR后的当前麻醉管理情况，估计了MMR患者临床恶性高热（MH）的发生率，并且是首个根据1987年北美恶性高热小组方案评估MMR与恶性高热易感性（MHS）一致性的研究。
1986年至1991年期间，执业麻醉医师根据琥珀酰胆碱（1975 - 1991年）使用后出现MMR的证据，转诊儿科患者进行活检。临床情况描述为单纯MMR或MMR后出现MH体征，包括动脉血二氧化碳分压>50 mmHg、动脉血pH≤7.25以及碱缺失>8。患者进行咖啡因 - 氟烷肌挛缩试验以确定MHS。
共评估了70例患者（50例男孩和20例女孩）。83%（70例中的58例）的麻醉采用氟烷 - 琥珀酰胆碱。68%（70例中的48例）的病例中麻醉被停止，11%（70例中的8例）继续使用非触发剂进行麻醉，13%（70例中的9例）继续使用触发剂进行麻醉。59%（70例中的41例）的患者通过肌肉活检被诊断为MHS。7%（70例中的5例）的患者在MMR后10分钟内出现临床MH。
本研究采用当前北美恶性高热小组方案，再次证实经肌肉活检确认与MMR相关的MHS发生率很高（59%，70例中的41例）。在MHS患者中，有5例出现临床MH体征。本研究中的大多数麻醉医师在面对MMR时停止了麻醉。由于MH具有潜在致死性且MMR与MHS之间的一致性>50%，MMR后最保守的做法是停止麻醉并观察患者是否有MH的临床证据。根据手术的紧迫性，一个可接受的替代方案是使用非触发剂继续进行MH麻醉，并进行适当监测。
