Awareness during anesthesia with sevoflurane: a case report

We report a case of a patient who experienced awareness during general anesthesia with sevoflurane. A 71-year-old man, weighing 57 kg, was operated on for a malignant tumor of the parotid gland. He was given 2 mg diazepam orally as a premedication. General anesthesia was induced by thiamylal 200 mg, fentanyl 50 microg, and up to 5% of sevoflurane. Muscle relaxation was obtained with vecuronium 6 mg, and the patient was intubated. After induction, fentanyl 150 microg was added, but no other intravenous anesthetics or muscle relaxants were used. The end-expiratory concentration of sevoflurane was maintained at 0.8% to 1.7% before the start of surgery, and 1.5% to 2.9% during surgery. The operation lasted for 10.4 hours. His left eye was guarded by ointment but kept open for observation by the surgeon of facial movement following muscle stimulation. The surgical course, emergence, and the postoperative course were uneventful. On the fifth postoperative day, the patient started to describe his visual memory during the operation, although he did not remember any pain or discomfort. We believe that visual input through his open eyes, the effect of cranial bone oscillation by the surgery, and the idiosyncrasy of the patient contributed to his intraoperative recall.     

Awareness and recall in outpatient anesthesia

We studied the incidence of awareness and explicit recall during general anesthesia in outpatients versus inpatients undergoing surgery. During a 14.5-mo period, we structurally interviewed 1500 outpatients and 2343 inpatients. Among outpatients, there were five cases of awareness and recall (one with clear intraoperative recollections and four with doubtful intraoperative recollections). Of the inpatients, six reported awareness and recall (three with clear and three with doubtful intraoperative recollections). The incidence of clear intraoperative recollections was 0.07% in outpatients and 0.13% in inpatients. The difference in the incidence was not significant. Among outpatients, those with awareness and recall were given smaller doses of sevoflurane than those without awareness and recall (P < 0.05). In conclusion, awareness and recall are rare complications of general anesthesia, and outpatients are not at increased risk for this event compared with inpatients undergoing general anesthesia. IMPLICATIONS: Rapid recovery from general anesthesia is a crucial element of outpatient surgery. However, this practice may predispose a patient to receive less anesthetic, with increased risk for awareness and recall. We have shown that outpatients undergoing an operation using general anesthesia are not at increased risk for awareness compared with inpatients.     

特殊听觉干预评估小儿术中知晓的准确性

目的 研究特殊听觉干预评估小儿术中知晓的准确性.方法 择期全麻下行脊柱侧弯后路矫形术的患儿34例,年龄5～15岁,体重16～73kg,ASA分级Ⅰ或Ⅱ级.于麻醉诱导前和术中唤醒结束后,通过耳机各给予1次不同的特殊听觉干预(60 dB,15s).于术后24 h内和术后5～7 d时对患儿进行访视,判定患儿对术中唤醒和特殊听觉干预的知晓情况.结果 34例患儿中3例因唤醒后躁动、1例因对访视产生厌恶情绪而排除.30例患儿中3例发生了确证唤醒知晓,1例为可疑唤醒知晓,术中唤醒知晓率为10%,但4例患儿中只有1例对术中特殊听觉干预发生知晓.30例患儿均能准确回忆起于麻醉诱导前给予的特殊听觉干预.结论 特殊听觉干预并不能准确地评估脊柱侧弯后路矫形手术患儿术中知晓的发生情况.     

General anesthesia in a case of right-sided aortic arch with Kommerell's diverticulum diagnosed on preoperative examination

Kommerell's diverticulum is a rare anomaly of the aortic arch. A 59-year-old man was scheduled for open reduction and internal fixation of his right proximal tibial fracture under general anesthesia. We diagnosed right-sided aortic arch by the chest X-ray and thoracic computed tomography. His trachea and esophagus were compressed by the aortic arch. He had complained of no dyspnea or dysphagia. Respiratory difficulty might be caused by muscle relaxants, intermittent positive pressure ventilation, change of intrathoracic pressure, postural change and overloaded infusion during general anesthesia in a case of right-sided aortic arch. We performed lumbar epidural anesthesia and inserted an i-gel after general anesthesia induction preserving spontaneous respiration in preparation for controlled ventilation or tracheal intubation via an i-gel. We could accomplish the operation uneventfully and he was discharged on POD 53. A supraglottic airway such as an i-gel was a useful device in the present case of right-sided aortic arch with Kommerell's diverticulum.     

Myoglobinemia in a patient due to positioning during nephrectomy

We report a case of myoglobinemia observed in the postoperative period due to forced positioning during nephrectomy. A 32-year-old male, weighing 93 kg, underwent the left nephrectomy due to renal cell carcinoma under general anesthesia with epidural block. The operation was performed uneventfully but he complained of severe pain in his right hip immediately after the recovery from anesthesia. Neither skin flush nor edema was observed and the other superficial tissue injury was not detected. On the day following the operation, severe myoglobinemia was observed and the serum myoglobin level increased to over 20,000 ng.ml-1. CT findings showed topical edema or necrosis of his right minor and medial gluteus muscle. Myoglobinemia continued only for 3 days after the operation without renal dysfunction. We may conclude that muscle injury during an operation followed by forced positioning for nephrectomy is caused not only by direct compression of the muscle, but also by obstruction of the profound intramuscular artery.     

Acute massive pulmonary embolism occurring during orthopedic surgery

We present an emergent surgical case of massive pulmonary embolism (MPE) that happened during orthopedic surgery. A 38-year-old man, who had bone fractures with his lumbar vertebra and ankle, underwent the internal fixation of the tibial bone with tourniquet under general anesthesia in our hospital. During this surgery, the pulse oxymeter showed a drop of arterial oxygen saturation suddenly. Immediately we installed a transesophageal echo (TEE) probe in the patient, and detected enlargement of the right ventricle and right atrial thrombus. Half an hour later, the thrombus disappeared from the right atrium and the patient showed hemodynamic shock. We performed emergent embolectomy immediately under moderate hypothermic complete cardiopulmonary bypass. The postoperative course was uneventful, and one month later, his orthopedic surgery underwent completely. We conclude that TEE was a useful devise for the diagnosis of intraoperative MPE.     

Possible venous air embolism during open eye surgery in a child

PURPOSE: Although venous air embolism is a well recognized complication within most surgical subspecialties, it has only been reported recently during eye surgery in one adult, and never before in a child. We describe the case of a 17-month-old boy who sustained a possible air embolism during repair of an open trauma of his right eye. CLINICAL FEATURES: A vitrectomy through the pars plana with air-fluid exchange of the posterior chamber was performed under general anesthesia to remove a foreign body which had impaled the optic nerve. A few minutes after removal of the foreign body, a notable decrease in end-tidal CO(2), oxygen saturation and arterial blood pressure occurred, requiring administration of a high inspired oxygen fraction and vasopressors. Venous air embolism was strongly suspected after other causes of a decrease of end-tidal CO(2) and hypoxemia had been excluded. An arterial blood gas confirmed hypoxemia and respiratory acidosis. CONCLUSION: Although venous air embolism is a rare complication of eye surgery, it should nevertheless be considered as a possible complication during air-fluid exchange vitrectomy in children.     

Intraoperative awareness: detected by the structured Brice interview?

BACKGROUND: Awareness is a rare complication in general anesthesia, but its consequences are stressful. Efforts must be undertaken to prevent, diagnose, and, if occurring, treat it. The incidence of awareness is higher following anesthesia involving the use of muscle relaxants. As a part of a quality assurance program at our short-stay surgery all patients exposed to general anesthesia are routinely subjected to a Brice interview, which aims to evaluate our standard anesthetic technique regarding awareness. METHODS: The Brice interview was used prospectively in 5216 patients given a propofol/opioid anesthetic for day-case or short-stay surgery. Neuromuscular blocks were used only for surgical needs, not routinely. All patients were interviewed on discharge from the recovery room. A second interview, according to Brice, was undertaken by telephone 3-7 days later in the case of a notable intraoperative event, or otherwise after postoperative patient complaints. All patients were also interviewed by telephone 1-2 days postoperatively. RESULTS: None of the patient interviews indicated awareness. This was also the case in five non-relaxed patients who had an incident of light anesthesia with eye opening and gross motor response without forewarning. Neuromuscular blockade was used in 7% of patients. DISCUSSION: We were unable to detect intraoperative awareness. The anesthetic regimen, including minimal use of muscle relaxants, might be beneficial for awareness prevention. Alternatively, the diagnostic power, the timing of the Brice interview, or the number of interviews performed may be questioned.     

Anesthetic management of a patient with narcolepsy

We report the anesthetic management of a narcoleptic patient performed using sevoflurane–remifentanil with bispectral index (BIS) monitoring. A 22-year-old man, who was diagnosed with narcolepsy at the age of 17, requested endoscopic sinus surgery, under general anesthesia, for chronic allergic rhinitis. On the morning of the day of operation, he took his daily dose of modafinil, used to control narcolepsy. Anesthesia was induced by 5% sevoflurane and maintained with sevoflurane and continuous infusion of remifentanil and 60% oxygen in conjunction with BIS monitoring. BIS values were between 47 and 58. Duration of surgery was 150 min. After surgery, the patient emerged from anesthesia within 10 min and was extubated. His recovery was uneventful. We found the use of BIS monitoring for titrating sevoflurane concentration in a narcoleptic patient is useful for preventing not only oversedation but also intraoperative awareness caused by the preoperative medication.     

两种快通道麻醉方法在肾移植手术的应用比较

目的比较两种快通道麻醉方法在肾移植手术的应用效果。方法 36例符合美国麻醉师协会（American Society of Anesthesiologists,ASA）分级Ⅲ~Ⅳ级的终末期肾病拟行肾移植术患者,采用随机数字法将患者随机分为Ⅰ组和Ⅱ组各18例。两组麻醉诱导用药相同。Ⅰ组吸入0.8%-1.8%七氟醚,使用小剂量顺式阿曲库胺[0.05-0.10 mg/（kg.h）]持续输注和常规剂量瑞芬太尼[0.1-1.0μg/（kg.min）]维持麻醉,预计手术结束前30 min停用顺式阿曲库胺,结束前15 min停止使用七氟醚,并将瑞芬太尼减低至维持量的1/10-1/5用至拔除气管导管。Ⅱ组使用丙泊酚[5-12 mg/（kg.h）]全凭静脉麻醉,以常规剂量顺式阿曲库胺[0.1-0.2 mg/（kg.h）]及瑞芬太尼[0.1-1.0μg/（kg.min）]维持麻醉,预计手术结束前30 min停用顺式阿曲库胺,手术结束后观察两组患者的睫毛反射时间、睁眼时间、拔管时间、术中知晓例数以及苏醒期躁动评分。结果Ⅰ组与Ⅱ组的睫毛反射时间、睁眼时间、拔管时间比较差异无统计学意义（均为P〉0.05）。两组患者均未出现术中知晓。Ⅰ组的躁动发生率明显低于Ⅱ组（P〈0.05）。Ⅰ组的顺式阿曲库胺、瑞芬太尼用量均明显少于Ⅱ组（均为P〈0.05）。结论七氟醚＋瑞芬太尼＋顺式阿曲库铵或丙泊酚＋瑞芬太尼＋顺式阿曲库铵这两种快通道麻醉方法用于肾移植手术均具有可控性良好、安全性高、患者苏醒迅速等特点,而七氟烷＋瑞芬太尼＋顺式阿曲库铵的组合更节省药物用量,且苏醒质量更高。     

Awareness during Anesthesia: A Closed Claims Analysis

Background: Awareness during general anesthesia is a frightening experience, which may result in serious emotional injury and post-traumatic stress disorder. We performed an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project to explore the contribution of intraoperative awareness to professional liability in anesthesia.

Methods: The database of the Closed Claims Project is composed of closed US malpractice claims that have been collected in a standardized manner. All claims for intraoperative awareness were reviewed by the reviewers to identify patterns of causation and standard of care. Logistic regression analysis was used to identify independent patient and anesthetic factors associated with claims for recall during general anesthesia compared to other general anesthesia malpractice claims.

Results: Awareness claims accounted for 79 (1.9%) of 4,183 claims in the database, including 18 claims for awake paralysis, i.e., the inadvertent paralysis of an awake patient, and 61 claims for recall during general anesthesia, i.e., recall of events while receiving general anesthesia. The majority of awareness claims involved women (77%), younger than 60 yr of age (89%), American Society of Anesthesiologists physical class I-II (68%), who underwent elective surgery (87%). Most (94%) claims for awake paralysis represented substandard care involving errors in labeling and administration, whereas care was substandard in only 43% of the claims for recall during general anesthesia (P < 0.001). Claims for recall during general anesthesia were more likely to involve women (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 1.58, 6.06) and anesthetic techniques using intraoperative opioids (OR = 2.12, 95% CI = 1.20, 3.74), intraoperative muscle relaxants (OR = 2.28, 95% CI = 1.22, 4.25), and no volatile anesthetic (OR = 3.20, 95% CI = 1.88, 5.46).     

Awareness in children: another two cases

Intraoperative awareness is an anesthesia complication and occurs when a patient becomes conscious during a procedure performed under general anesthesia and subsequently has recall of these events. Awareness is well described phenomenon in adults, with an incidence of 0.1–0.2 % for low-risk surgical procedures. Recent studies have shown that awareness in children is more common than in adults. However, causes and the long-term psychological impact of awareness in children are unknown. We report on two cases of intraoperative awareness in children in an attempt to throw further light on this complex problem.     

Intraoperative cardiac arrest due to coronary vasospasm after tourniquet release--a case report

A 55-year-old man with no past history of ischemic heart disease underwent open reduction and internal fixation of the right arm because of an open fracture. Under general anesthesia with brachial plexus block, the operation was started after the upper arm had been pressurized at 280 mmHg by tourniquet. The patient had cardiac arrest 15 min after the tourniquet release, and was resuscitated by CPR. Postoperative intracoronary infusion of acetylcholine revealed that the coronary artery is sensitive to the agent, indicating that the intraoperative cardiac arrest might have been due to coronary vasospasm. Although the similar case is rare, attention should be taken during the anesthetic management with the use of tourniquet.     

Awareness during anesthesia: a closed claims analysis.

BACKGROUND: Awareness during general anesthesia is a frightening experience, which may result in serious emotional injury and post-traumatic stress disorder. We performed an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project to explore the contribution of intraoperative awareness to professional liability in anesthesia. METHODS: The database of the Closed Claims Project is composed of closed US malpractice claims that have been collected in a standardized manner. All claims for intraoperative awareness were reviewed by the reviewers to identify patterns of causation and standard of care. Logistic regression analysis was used to identify independent patient and anesthetic factors associated with claims for recall during general anesthesia compared to other general anesthesia malpractice claims. RESULTS: Awareness claims accounted for 79 (1.9%) of 4,183 claims in the database, including 18 claims for awake paralysis, i.e., the inadvertent paralysis of an awake patient, and 61 claims for recall during general anesthesia, ie., recall of events while receiving general anesthesia. The majority of awareness claims involved women (77%), younger than 60 yr of age (89%), American Society of Anesthesiologists physical class I-II (68%), who underwent elective surgery (87%). Most (94%) claims for awake paralysis represented substandard care involving errors in labeling and administration, whereas care was substandard in only 43% of the claims for recall during general anesthesia (P < 0.001). Claims for recall during general anesthesia were more likely to involve women (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 1.58, 6.06) and anesthetic techniques using intraoperative opioids (OR = 2.12, 95% CI = 1.20, 3.74), intraoperative muscle relaxants (OR = 2.28, 95% CI = 1.22, 4.25), and no volatile anesthetic (OR = 3.20, 95% CI = 1.88, 5.46). CONCLUSIONS: Deficiencies in labeling and vigilance were common causes for awake paralysis. Claims for recall during general anesthesia were more likely in women and with nitrous-narcotic-relaxant techniques.     

Right median nerve injury following laparoscopic sigmoidectomy

Brachial plexus injury has often occurred secondary to malposition of the patient during general anesthesia. We have experienced median nerve injury following laparoscopic sigmoidectomy. A 61-year-old man with diabetes and hypertension received laparoscopic sigmoidectomy under general and epidural anesthesia. Tracheal intubation was easy without excessive retroflextion of his neck after anesthesia induction with fentanyl, propofol, and vecuronium. Both his upper arms were abducted to 80 degrees and his elbows were extended on a padded arm board. The shoulder braces were placed over both his acromioclavicular joints. His head remained in neutral position. Anesthesia was maintained with air, oxygen, sevoflurane, fentanyl, and vecuronium using mepivacaine via epidural catheter. During surgical procedures, he was in a combined lithotomy and head down position at maximum of 20 degrees. The operative table was tilted to the right at maximum of 20 degrees. The operation was finished successfully in 2 hours and 40 minutes without a special event. Postoperatively, he complained of numbness of the first, second, and third digits, and the radial side of fourth digit in his right hand. The redness on both his shoulders was observed. Muscle weakness and motor disturbance were not observed. Orthopedic surgeon diagnosed him as right median nerve injury. His symptoms improved gradually by physical training and disappeared one week after the operation. We suspect that his right median nerve injury was caused by compression and stretching of the brachial plexus in head down position, right lateral tilt table, use of shoulder brace, laparoscopy, abduction of the upper arm, and extension of the elbow. In laparoscopic operation in head down position, we should avoid using the shoulder brace to minimize the risk of brachial plexus injury. The arms should be approximated to the sides as nearly as possible and the elbows should be gently flexed to unload the median nerve and relieve tension on the brachial plexus.     

The effect of encephalogram bispectral index monitoring during total intravenous anesthesia with propofol in outpatient surgery]

OBJECTIVE: To assess the effect of monitoring the encephalogram bispectral index (BIS) during outpatient surgery. Outcome measures were amount of propofol administered, awakening and discharge. MATERIAL AND METHODS: Forty consecutive outpatient surgery patients were studied. The patients gave informed consent and received general intravenous anesthesia with propofol administered through a laryngeal mask using a computerized system (Diprifusor(R)). Two groups were formed: in group A, BIS was monitored, although the information was hidden from the anesthesiologists, who used the usual signs (loss of blinking reflex, pupil size and hemodynamic response) to guide anesthesia; in group B the anesthesiologists used BIS monitoring to guide propofol administration. Measurements were blood pressure, heart rate and BIS at six times during the procedure (T1-T6). Other data recorded were age, weight, height, propofol consumption in relation to weight and duration of procedure, consumption of rocuronium and alfentanil, duration of propofol infusion, time from withdrawal of propofol until eye opening, duration of stay in the post-anesthesia intensive care unit and time until total recovery. A questionnaire assessed the presence of intraoperative awareness and degree of satisfaction. The data were analyzed by Student's t and a chi square tests, with statistical significance at p < 0.05. RESULTS: Demographic variables (age, weight and height) were similar, as were duration of propofol infusion, total dose of alfentanil and rocuronium, evolution of blood pressure and heart rate. Statistically significant differences in BIS were observed at two times, T4 and T5; total propofol administered was 32.6% lower in group B; and time until eye opening was significantly shorter in group B. No significant differences were observed for time until full recovery. No instances of intraoperative awareness were reported and satisfaction was high in both groups. CONCLUSION: BIS monitoring allows for propofol titration that leads to a mean reduction of 32.6% in consumption, shortening the time until eye opening without causing intraoperative awareness or reducing patient satisfaction.     

A case of awareness with sevoflurane and epidural anesthesia in ovarian tumorectomy

We experienced a case of awareness during ovarian tumorectomy in a patient who was anesthetized with sevoflurane and epidural anesthesia. A 74-year-old woman was scheduled for resection of an ovarian tumor. After epidural catheter insertion, anesthesia was induced with 60 mg of propofol and 6 mg of vecuronium, and anesthesia was maintained with epidural anesthesia (1% mepivacaine), 1 to 2% sevoflurane, and 66% nitrous oxide in oxygen. The operative course was uneventful and the total operation time was 2 hours and 50 minutes. Two days after the operation, we were surprised to learn that the patient complained of awareness during the surgery.     

Massive pulmonary embolism after application of an Esmarch bandage

A 71-yr-old patient who underwent spinal anesthesia for left femoral fracture operation became hypotensive and unconscious after the application of an Esmarch bandage. The transesophageal echocardiography performed during resuscitation revealed pulmonary embolism and acute right ventricular failure. Pulmonary embolectomy with cardiopulmonary bypass was undertaken immediately after the echocardiographic diagnosis. Extracorporeal membrane oxygenation was used after the operation to support the failing right ventricle. The patient was successfully weaned from extracorporeal membrane oxygenation 10 days after the operation. We conclude that transesophageal echocardiography can be very useful in the immediate differential diagnosis of sudden cardiovascular collapse and that extracorporeal membrane oxygenation can be very helpful when acute right ventricular failure follows massive pulmonary embolism. IMPLICATIONS: Transesophageal echocardiography was highly valuable in finding the cause of sudden intraoperative cardiovascular collapse. The use of extracorporeal membrane oxygenation to support the failing right ventricle after emergent pulmonary embolectomy could help to rescue patients with massive pulmonary embolism.     

Intraoperative awareness during propofol anesthesia with epidural anesthesia

This report describes a case of awareness and recall during propofol anesthesia combined with epidural anesthesia in a 32-year-old woman scheduled for a resection of left ovarian tumor. After induction, anesthesia was maintained with propofol and epidural anesthesia. About one hour into maintenance, the patient was moving with haemodynamic signs suggesting inadequate analgesia. Immediately after extubation, the patient could recall the abdomen being touched during laparotomy. This case indicates that even if appropriate dose of propofol is administrated, intraoperative awareness may occur especially with inadequate analgesia.     

Examination under anesthesia prior laparoscopic appendicectomy: does it change the approach?

The clinical finding of a mass in the right iliac fossa during the course of diagnosis of acute appendicitis may affect the management approach. A mass is sometimes only evident when the abdomen is examined under anesthesia. This study was conducted to assess the significance of examination under anesthesia and analyze the outcome of laparoscopic exploration and its correlation with the finding of a mass that can be felt only under anesthesia. We conducted a prospective study over 12 months on patients diagnosed with acute appendicitis who were treated with laparoscopic approach. There were 179 patients (101 females) who underwent laparoscopic appendicectomy; 20 cases (11%) were converted to open appendicectomy. Examination under anesthesia revealed a mass in 20 patients (11%). The rate of conversion to open operation was 65% (13 patients) in those who had palpable mass and 4% (7 patients) in those who had no mass (P<0.0001). This study has shown that most patients with a mass found under anesthesia will need conversion of the laparoscopic procedure to an open operation. The recommendation from this study therefore is that all patients planned to have a laparoscopic appendicectomy should have examination under anesthesia; if a mass is found, then the procedure should be converted to open operation from the beginning.