ASA and CDC Plan National Study of Anesthesia Outcome

Fredrick K. Orkin, M.D.

How safe is anesthesia now? How can anesthesia care be made safer? Almost 25 million surgical operations are performed annually in U.S. acute care hospitals, yet remarkably little is known about the rates and causes of serious anesthesia-related complications. Thus, the American Society of Anesthesiologists and the federal Centers for Disease Control recently agreed to jointly support a pilot study during 1988 to help plan a national study of mortality and severe morbidity associated with anesthesia. The pilot study will not provide outcome data or test hypotheses but rather will test and improve the proposed methodology for the national study.

The national study seeks to learn how to improve the quality of anesthesia care. Data will be collected in a representative sample of hospitals and analyzed to estimate national and regional incidence rates of anesthesia-related mortality and severe morbidity. The focus will he factors having potential for preventive intervention: Anesthesia factors such as technique and patient monitoring; patient factors such as the presence of hypertension, obesity, and smoking; and hospital factors such as the type of anesthesia provider and volume surgery.

All mortality and severe morbidity occurring within 48 hours of an anesthetic will be studied in patients undergoing inpatient and outpatient surgery, cesarean section, and radiologic procedures. An in-hospital investigator will collect detailed information which will be reviewed in a blinded fashion by independent expert panels consisting of two anesthesiologists and one surgeon. These panels will assess the contribution of the anesthesia care to the adverse event. In addition, using other patients at the same hospitals who (lid not suffer complications, a case-control study will examine the anesthesia and personal factors that can affect the occurrence of anesthetic-related adverse events. The analysis will focus on anesthesia and patient variables, while controlling for such factors as type of surgical procedure and the patient’s age and ASA physical status classification.

A pilot study is necessary to improve the protocol and, in particular, to determine the feasibility of different aspects of what is expected to be a three to five-year, multimillion-dollar study for which governmental, industrial, and other private funding would be sought. It is recognized that substantial scientific issues must be resolved and funding obtained before such a large effort can be launched. The pilot study will involve three months’ data collection in five hospitals chosen so that there is representation of a hospital with a medical school affiliation, a community hospital with no medical school affiliation, and anesthesia provided by nurse anesthetists.

This joint effort re-suits from more than I 8 months’ collaboration between Dr. Douglas N. Klaucke of the CDC’s Division of Surveillance and Epidemiologic Studies and the ASA Task Force on Morbidity and Mortality, drawn from the Committee on Patient Safety and Risk Management, chaired by Dr. Ellison C. Pierce, Jr. Task Force members are Drs. Jeffrey B. Cooper, Stephanie M. Duberman, Fredrick K. Orkin, and Alan D. Sessler. For the pilot study, the ASA will provide administrative support and anesthesia consultation, the CDC will provide epidemiologic consultation, a blanket of confidentiality over data, and oversight of the project. Battelle Human Affairs Research Centers, a health care consulting firm, will collect the data as a subcontractor. This collaboration is already being described as a model for mutual cooperation between a medical society and a governmental agency. Further information was presented in the February issue of the ASA Newsletter and is available from Task Force members.

Dr. Orkin, University of California at San Francisco, is a Task Force member and co-e6tor of Complications in Anesthesiology.