[Annual study of anesthesia-related mortality and morbidity in the year 2000 in Japan: the outlines--report of Japanese Society of Anesthesiologists Committee on Operating Room Safety].

This report contains anesthesia-related mortality and morbidity in Japanese Society of Anesthesiologists Certified Training Hospitals (JSACTH) in the year 2000, as a part of the second series of annual studies started in 1999. JSA Committee on Operating Room Safety (CORS) sent confidential questionnaires to 794 JSACTH and received effective answers from 65.5% of hospitals. A total number of 941,217 anesthetics were documented. The respondents were asked to report all cases of cardiac arrests and other critical incidents (serious hypotension, serious hypoxemia and others), and their outcomes (death in operating room, death within 7 days, transfer to vegetative state and rescue without sequelae) as well as one principal cause for each incident from the list of 52 items. They were also requested to submit the tabulation of patients by ASA physical status, age distribution, surgery sites and anesthetic methods. Analysis was made by total incidents under anesthesia/surgery, and also by incidents totally attributable to anesthetic management (AM), due to preoperative complications (PC), due to intraoperative pathological events (IP) and due to surgery (SG). This paper focused analysis on entire patients, since analyses with special reference to ASA physical status, age distribution, surgery sites and anesthetic methods were reported previously. Total incidence of cardiac arrest under anesthesia/surgery was 6.52 per 10,000 anesthetics. PC, IP and SG occupied 46.4%, 19.1% and 23.0% of principal causes of total cardiac arrest, respectively. AM occupied only 8.1% of the principal causes and the incidence was 0.53 per 10,000. The most frequent cause of cardiac arrest in 52 more detailed classification of principal causes was preoperative hemorrhagic shock that occupied 23.3% of all cardiac arrests. The second was massive hemorrhage and/or hypovolemia due to surgical procedures (10.6%), and the third was surgery itself (9.5%). Prognosis of the cardiac arrest was worst in that due to PC, 73.7% of cardiac arrests died in the operating room or within 7 days after surgery and only 20.4% survived without sequelae. The best prognosis was found in cardiac arrest due to AM, 76.0% survived without sequelae and 12.0% died. The mortality rate after cardiac arrest was 3.52 per 10,000 anesthetics, of them 0.06 was due to AM, 0.39 due to IP, 2.23 due to PC and 0.76 due to SG. The mortality rate after critical incidents other than cardiac arrest such as severe hypotension and severe hypoxemia was 3.48, and of them 0.03 was due to AM, 0.18 due to IP, 2.45 due to PC and 0.81 due to SG. The final mortality rate attributable to anesthesia/surgery including deaths after cardiac arrest and after other critical incidents was 7.00 per 10,000 anesthetics and very close to 7.18 [6.22, 8.13], that of mean [95%C.I.] in 1994-1998, and 7.19 in 1999. The final mortality rate totally attributable to AM was 0.10 per 10,000 anesthetics, which was significantly improved from 0.21 [0.15, 0.27], that of mean [95%C.I.] in 1994-1998, but not different from 0.13 in 1999. IP, PC and SG showed the final mortality rate of 0.56, 4.69 and 1.57, respectively. Five major causes of all critical incidents were massive hemorrhage due to surgical procedures (13.8%), preoperative hemorrhagic shock (13.1%), surgical technique (8.6%), inappropriate airway management (6.2%) and preoperative respiratory complication (5.7%). Drug overdose or wrong choice (2.7%) as a human error occupied the 10th. In conclusion, the obtained incidences as to death, other critical incidents and their outcomes as well as the occurrence of principal causes in 2000 study were remarkably close to those in 1999 study. We expect that this second series of annual studies for five-years should reveal precise and definite direction for us to reduce anesthesia-related mortality and morbidity.