[Critical events in the operating room among 1,440,776 patients with ASA PS 1 for elective surgery].

BACKGROUND: The Japanese Society of Anesthesiologists (JSA) survey of critical incidents in the operating room has shown that preoperative complications are the leading causes of critical incidents, and affect the occurrence, severity and outcome of critical incidents which are due to causes other than preoperative complications. Causes of critical events in the operating room were examind in patients for elective surgery with American Society of Anesthesiologists physical status (ASA PS) 1. METHODS: JSA has conducted annual surveys of critical incidents in the operating room by sending and collecting confidential questionnaires to all JSA Certified Training Hospitals. From 1999 to 2002, 3,855,384 anesthesia patients were registered. Among these, 1,440,776 patients with ASA PS 1 for elective surgery were analyzed. The causes of critical incidents were classified as follows: totally attributable to anesthetic management (AM), mainly to intraoperative pathological events (IP), to preoperative complications (PC), and to surgical management (SM). IP consists of coronary ischemia mainly due to coronary vasospasm, arrhythmias, pulmonary embolism, and other conditions. RESULTS: The incidences of cardiac arrest, critical incidents other than cardiac arrest and subsequent death were 9.86, 59.41 and 3.12 per 100,000 anesthesia cases, respectively. IP and SM were responsible for 36.6% and 34.5% of cardiac arrest, respectively. AM and SM were responsible for 46.7% and 26.8% of critical incidents other than cardiac arrest, respectively. SM, IP and AM were responsible for 66.7%, 22.2% and 4.4% of subsequent deaths (within 7 postoperative days), respectively. Coronary ischemia and pulmonary embolism were the main causes of death due to IP. The incidences of cardiac arrest and death totally attributable to AM were 1.87 and 0.14 per 100,000 anesthesia cases, respectively. Medication problems were responsible for 48.1% of arrests, while airway/ventilation problems were for 57.2% of critical incidents other than arrest. Human factors (SM combined with AM) were responsible for 53.5%, 73.5%, and 71.1% of cardiac arrest, critical incidents other than arrest and death, respectively. CONCLUSIONS: Even in elective patients with good physical status, non-lethal incidents were not rare, and lethal incidents were also reported. We should pay significant attention to the following findings, and take some measures to overcome these problems especially related to human factors. Firstly, SM badly harmed some operative patients. Secondly, coronary vasospasm and pulmonary embolism were the main causes of death due to IP. Thirdly, drug administration and airway/ventilation management were the major causes of critical incidents totally attributable to AM. Human factors were responsible for 70.6% of critical incidents and 71.1% of deaths.

[Critical incidents during regional anesthesia in Japanese Society of Anesthesiologists-Certified Training Hospitals: an analysis of responses to the annual survey conducted between 1999 and 2002 by the Japanese Society of Anesthesiologists].

BACKGROUND: Recently, a national survey in France including 35,439 patients who had received spinal anesthesia showed that the incidences of cardiac arrest and mortality associated with spinal anesthesia were 2.5 and 0.8 per 10,000 anesthetics, respectively. In this study, we investigated these values using data obtained from annual surveys conducted by the Japanese Society of Anesthesiologist (JSA). METHODS: Since 1994, JSA has conducted annual surveys concerning critical incidents in the operating theater by sending confidential questionnaires to JSA-certified training hospitals, then collecting and analyzing the responses. We investigated critical incidents associated with regional anesthesia using data from annual surveys between 1999 and 2002. The questionnaire was identical in each survey conducted during these years. The total number of anesthetics available for this analysis was 3,855,384, of which spinal anesthesia, combined spinal-epidural anesthesia and epidural anesthesia were performed in 409,338, 146,282, and 69,001 patients, respectively. In patients receiving regional anesthesia, 628 critical incidents including 108 cardiac arrests, and 45 subsequent deaths were reported. The causes of critical incidents were classified as follows: totally attributable to anesthetic management, due mainly to intraoperative pathological events, preoperative complications, and surgical management. IP consists of coronary ischemia including coronary vasospasm not suspected preoperatively, arrhythmias including severe bradycardia, pulmonary thromboembolism, and other conditions. Mortality was determined by postoperative day 7. Statistical analysis was performed by chi-square test and Mann-Whitney test. A p value less than 0.05 was considered significant. RESULTS: The incidences of cardiac arrest and mortality due to all etiologies were 1.69 and 0.76 with spinal anesthesia, 1.78 and 0.68 with combined spinal-epidural anesthesia, and 1.88 and 0.58/10,000 anesthetics with epidural anesthesia, respectively. The incidences of cardiac arrest and mortality due to anesthetic management were 0.54 and 0.02 with spinal anesthesia, 0.55 and 0.00 with combined spinal-epidural anesthesia, and 0.72 and 0.14/10,000 anesthetics with epidural anesthesia, respectively. These values did not significantly differ among regional anesthesia. Death attributable to anesthetic management was reported in 2 patients: both patients were classified as ASA-PS 3 E, and developed cardiac arrest; one due to inadvertent high spinal anesthesia with spinal anesthesia, and the other due to local anesthetic intoxication with epidural anesthesia. Anesthetic management and intraoperative pathological events comprised 33 and 43% of cardiac arrests, respectively. The distribution of causes of death was as follows: anesthetic management, 5%; intraoperative pathological events, 34%; preoperative complications, 35%; surgical management, 26%. Among the causes of anesthetic management-induced critical incidents, inadvertent high spinal anesthesia was the leading cause of cardiac arrest in spinal and combined spinalepidural anesthesia: 90% of arrests occurred in patients with ASA-PS 1+2; 88% in patients below 65 years of age; 45 and 25% in patients undergoing hip or lower extremities surgery, and cesarean section, respectively. Among the causes of intraoperative pathological event-induced critical incidents, pulmonary thromboembolism was the leading cause of cardiac arrest in spinal and combined spinal-epidural anesthesia: 59% of arrests occurred in patients with ASA-PS 1+2; 81% in patients above 66 years of age; 91% in patients undergoing hip or lower extremity surgery. CONCLUSIONS: The incidence of cardiac arrest and mortality associated with spinal anesthesia in Japan was shown to be in the same order as in France by analyzing a larger population. In patients with good ASA-PS, critical incidents occurred more often under regional anesthesia than under general anesthesia. Inadvertent high spinal anesthesia should be carefully avoided. We should also pay much attention to subclinical deep vein thrombosis in patients who were scheduled for hip or lower extremity surgery, and tourniquet- or bone cement-associated pulmonary embolism in these patients.

[Supplemental survey in 2003 concerning life-threatening hemorrhagic events in the operating room].

BACKGROUND: We previously showed that pre-operative hemorrhagic shock and surgical hemorrhage were the major causes of life-threatening events in the operating room and subsequent fatality. We investigated the background of these events. METHODS: The Subcommittee on Surveillance of Anesthesia-Related Critical Incidents, Japanese Society of Anesthesiologist (JSA) sent confidential questionnaires to all JSA-certified training hospitals (n=862). The questionnaires were composed of two parts: one for examining all life-threatening events in the operating room and the other for examining the background of massive hemorrhage in the operating room. The number of patients registered between January 1, 2003 and December 31, 2003 was 1,367,790 from 782 hospitals. Life-threatening hemorrhagic events were reported in 1,011 patients, of whom 876 patients were available for further analysis of the background of the events. Fatality within 7 postoperative days following these events was 45.4%. RESULTS: In patients who developed life-threatening events due to hemorrhage, 35.2% had blood loss of more than 12 l x 60 kg(-1) of body weight, 44.9% had a maximal hemorrhagic speed of more than 240 ml x min(-1) x 60 kg(-1) of body weight, and 39.1% had a minimal hemoglobin concentration of less than 5 g x dl(-1). The main sources of hemorrhage were as follows: the abdominal aorta, 15.4%; the thoracic aorta, 14.0%; the liver, 12.6%; intra-cranium, 8.2%; the pelvic organs, 8.0%; celiac or mesenteric artery, 7.8%; the lung, 7.1%. Of patients who developed life-threatening events due to preoperative hemorrhagic shock, 18.3% underwent cardiac massage preoperatively, 50.0% lost consciousness, 58.5% were intubated, and 16.4% were retrospectively judged to have had no operative indications. Human factors also affected the life-threatening events due to preoperative hemorrhagic shock: delayed decision making concerning indications for surgical treatment, 15.6%; delayed admission to the operating room, 16.6%; delayed supply of blood products, 25.5%; problems in surgical management, 16.3%; problems in anesthetic management, 28.1%. These problems in anesthetic management included shortage of supportive anesthesiologists. This was partly explained by the time of their admission to the operating room: 67.0% of the patients admitted during the week end or at night. Of the patients who developed life-threatening events due to surgical hemorrhage, 58.0% were predicted preoperatively to develop massive hemorrhage by anesthesiologists, and 66.7% were informed of the risks of massive hemorrhage and associated complications. The main causes of surgical hemorrhage were as follows: adhesion or invasion, 44.7%; and problems in surgical judgments or techniques, 43.7%. Anesthetic management affected the development of life-threatening events in these patients: lack of infusion prior to hemorrhage, shortage of supportive anesthesiologists, delay in ordering additional blood products, delayed judgment to start blood transfusion, and shortage of rapid infusion/transfusion apparatus. Delay for hospitals in obtaining blood supply from blood banks was reported in 13.0% of cases, and delayed supply from inhospital blood transfusion service to the operating room in 16.0%. Despite massive hemorrhage, ABO cross-matching was omitted only in 13.4% of patients, and transfusion of ABO-compatible, instead of ABO-identical red blood cells, was performed only in 1.3%. CONCLUSIONS: To reduce life-threatening hemorrhagic events in the operating theater, reorganization of emergency medical service and blood supply, improvement of surgical techniques, improved triage of patients with hemorrhagic shock, flexible application of compatible blood products in emergency situations, and improvement of the quality and number of anesthesiologists should be considered.

[Surgical volume and mortality due to intraoperative critical incidents at Japanese Society of Anesthesiologists certified training hospitals: an analysis of the annual survey in 2002].

BACKGROUND: We have previously showed that surgical volume affects mortality due to intraoperative critical incidents among patients undergoing cardiac surgery, the surgery with the highest risk, using data obtained by the annual survey in 2001 conducted by the Japanese Society of Anesthesiologists (JSA). In this study, we investigated whether surgical volume affects mortality due to intraoperative critical incidents independent of the surgical site. METHODS: We investigated this relationship using data obtained from the 2002 annual survey conducted by the Subcommittee on Surveillance of Anesthesia-related Critical Incidents, JSA. Between January 1, 2002 and December 31, 2002, 1,987,988 patients were registered from 704 training hospitals certified by the JSA. Intraoperative critical incidents occurred in 2,844 patients. Of these, 804 patients died within 7 postoperative days. The overall mortality was 4.61 per 10,000 anesthetics. Hospitals were divided into 5 groups according to their annual surgical cases: Group A, fewer than 1,000 (62 hospitals); Group B, 1,000-1,999 (204 hospitals); Group C, 2,000-3,999 (288 hospitals); Group D, 4,000-5,999 (110 hospitals); Group E, more than 6,000 (40 hospitals). Hospitals were also divided into 2 groups according to mortality: Group 1, under 20.00 per 10,000 anesthetics (672 hospitals); Group 2, equal to or higher than 20.00 per 10,000 anesthetics (32 hospitals). Total number of deaths in Group 2 was 158. Mortality was expressed as the mean (95% confidence interval). Statistical analysis was performed using chi-square test and Fisher test. A p value of <0.05 was considered significant. RESULTS: The mortality rates in Groups A-E were 14.89 (8.48-21.3), 3.86 (3.05-4.67), 3.88 (3.19-4.57), 4.04 (3.20-4.88), and 3.12 (2.19-4.05) per 10,000 anesthetics, respectively. Average surgical cases and mortality in Group 1 were 2,789 (2,775-3,002) and 3.24 (2.90-3.58), respectively, while those in Group 2 were 1,672 (1,243-2,101) and 22.18 (30.58-45.94), respectively. If all patients in Group 2 (n=53,509) had been treated in the hospitals of Group 1, 139-143 deaths might have been avoided. CONCLUSIONS: Surgical volume was shown to affect mortality independent of the surgical site. Hospitals with low surgical volume should pay significant attention to improving surgical outcomes. These results also suggest that centralization or regionalization should be discussed from the perspective of socio-economical problems as well as patient safety.