ASA President Offers 6 Observations on Study of CRNAs as Sole Provider of Anesthesia Services

Alexander A. Hannenberg, MD, president of American Society of Anesthesiologists, discusses his thoughts and observations regarding the recent study by Research Triangle Institute International, funded by the American Association of Nurse Anesthetists and published in Health Affairs, claiming certified registered nurse anesthetists who provide anesthesia services without supervision from a physician do not put patients at increased risk.

Dr. Alexander A. Hannenberg: As President of the ASA, I appreciate the opportunity to provide important perspective on the study "No Harm Found When Nurse Anesthetists Work Without Supervision By Physicians" from the anesthesiologists' viewpoint. The following is ASA's overview of the study along with the resources that support the points.

1. The study's methodology relies on weak billing data:

• • It examines data based around the -QZ modifier, which overstates independent practice by a CRNA
    • It does not distinguish between complications resulting from surgery or anesthesia
    • It does not discriminate between conditions existing prior to surgery and those resulting from surgical or anesthetic care
    • A surgeon is still present and participating in patient care in opt-out states
  • 481,000 cases analyzed in the study would have produced two deaths related to anesthesia, an obviously insufficient number to support any conclusions about mortality

2. Anesthesiologists are experts in patient safety. Recent data showed one death per 200,000-300,000 anesthetics administered. (Committee on Quality of Healthcare in America, Institute of Medicine: "To Err is Human, Building a Safer Health System." Edited by Kohn L, Corrigan J, Donaldson M. Washington, National Academy Press, 1999, p. 241)

3. Anesthesiologists not only care for patients undergoing the most complex procedures (base unit differential) but also the sicker patients undergoing all procedures (unrecognized selection bias). These considerations would suggest dramatically better outcomes for CRNAs, but this is not seen. In fact, CRNA only cases (-QZ) actually showed worsening mortality and complications, while other groups improved (see table below). Even equivalent outcomes with lower risk cases is a troubling finding. And the most significant improvement in mortality and complications took place in the anesthesia care team (ACT) model of practice, further supporting the value of anesthesiologists involvement in care. (Reference: Jeffrey Silber, MD, PhD, 2000 study "Anesthesiologist Direction and Patient Outcomes": >6 excess deaths/1000 cases from failure to rescue from surgical or anesthetic complication in absence of anesthesiologist)

From Table 4 in "No Harm Found When Nurse Anesthetists Work Without Supervision" study:

Mortality

Complication

The authors of the study make no apology for the disturbing trend in their own data toward increasing frequency of mortality and complications in nurse-administered anesthesia during the opt-out "experiment" as compared to improved outcomes in physician and ACT cases.

4. Cost of care is equivalent. Considering that the payment for anesthesia services under Medicare's system (adopted by most private insurers, too) is identical whether provided by an unsupervised nurse, solo physician or the physician/CRNA team, the fallacy of the "cost effective" claim is evident.

5. The study understates the differences in training of anesthesiologists and nurse anesthetists. Nurse anesthetists typically receive approximately 2.5 years of post-baccalaureate education; anesthesiologists receive eight years, including a broad foundation in general medicine, intensive care and pain management. The prolonged period of training is to acquire the knowledge base and skills to provide expert care of the patient and all their co-existing disease before, during and after surgery.

6. Overwhelming public preference for physician supervision (A 2001 study by The Terrance Group, titled "National Anesthesia Study III: A Survey of Public Opinion Attitudes," revealed that 70 percent of all respondents (and 77 percent of Medicare beneficiaries) would oppose allowing a nurse anesthetist to administer anesthesia without medical supervision if an MD could supervise the nurse at no additional cost to the patient. Sixty-three percent of all respondents (and 70 percent of Medicare beneficiaries) opposed the decision to drop the requirement for anesthesia supervision by a doctor.). Public policy should reflect this preference.

Read the American Society of Anesthesiologists official statement on the nurse anesthetists study.