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ICES study finds anesthesia consultation before major surgery reduces hospital stay


A simple consultation with an anesthesiologist before a major surgical procedure could cut hospital stays by 11,000 days a year in Ontario, according to a study released by the Institute for Clinical Evaluative Sciences (ICES) today.

The study of 271,082 people who had major elective, non-cardiac surgery in Ontario from 1994 to 2004 found:

  • Patients who had seen an anesthesiologist in consultation before surgery stayed in hospital for a shorter period of time than patients who had not.
  • The average difference per patient was about 1/3 of day.
  • Since at least 32,000 people undergo major surgery in Ontario every year, this difference corresponds to more than 11,000 days of hospitalization that may be prevented, if patients regularly see anesthesiologists to help prepare for surgery.
  • Patients who had an anesthesia consultation underwent more routine testing prior to surgery (e.g. pulmonary function tests, echocardiograms).
  • Anesthesia consultation may lead to more efficient use of a scarce resource – hospital bed days – however, it was not associated with a reduction in mortality.
  • Many anesthesiologists evaluate patients before elective surgery, in what is called a ‘preoperative consultation’. This preoperative consultation is done in an outpatient clinic several weeks prior to surgery and is important because many people who require major surgery also have other important medical problems, such as diabetes, heart disease or high blood pressure. In this situation, the anesthesiologist would investigate and manage these other medical problems, so as to ensure that the planned surgery will be as safe as possible.

“Although patients stayed in hospital for a shorter time if an anesthesiologist evaluated them before surgery, we need to examine whether this approach to delivering care is more efficient. Given the increased use of laboratory tests and the outpatient clinic visits required for the consultation, it will be important to determine whether it is cost-effective for all patients to undergo consultation before major elective surgery, or whether it should be reserved for high risk procedures alone,” says Dr. Duminda Wijeysundera, lead researcher on the study.

Author affiliations: ICES (Dr. Wijeysundera, Dr. Austin, Dr. Hux, Dr. Laupacis); Department of Health Policy Management and Evaluation, UofT (Dr. Wijeysundera, Dr. Austin, Dr. Hux, Dr. Laupacis); Department of Anesthesia, Toronto General Hospital and UofT (Dr. Wijeysundera, Dr. Beattie); Department of Public Health Sciences, UofT (Dr. Austin); Department of Medicine, Sunnybrook Health Sciences Centre and UofT (Dr. Hux); Keenan Research Centre, Li Ka Shing Knowledge Institute of St. Michael’s Hospital, (Dr. Laupacis); Department of Medicine, St. Michael’s Hospital and UofT (Dr. Laupacis) Ontario.

The study “A population-based study of anesthesia consultation before major non-cardiac surgery” is in the March 23, 2009 issue of Archives of Internal Medicine.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.



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