One of the leading technologies designed to detect anesthesia awareness in surgical patients might not be any more effective than a conventional, and less expensive, technique, according to a study published in the March 13 issue of the New England Journal of Medicine.

The study compared nearly 2,000 patients who received either Bispectral Index-guided anesthesia or end-tidal anesthetic gas-guided anesthesia. Researchers found that BIS monitoring didn't result in a lower incidence of anesthesia awareness among patients. Instead, both groups reported two definite cases of awareness. Five other patients - four in the BIS group and one in the end-tidal group - were suspected to have experienced awareness. The researchers conclude against supporting BIS monitoring as a standard of practice.

Aspect Medical Systems, which manufactures the BIS system, took issue with the researchers' interpretation of the study's results. In a statement, they argue that the study did not compare BIS with standard practice, but rather with a protocol-based approach to anesthetic administration.

"The ETAG-guided protocol used in the NEJM study instructed the anesthesia professionals to use a certain amount of inhaled anesthetics and audible alarms at the minimal level," says Scott Kelley, MD, Aspect Medical's vice president and medical director. "This is not how anesthesia professionals routinely practice."

Dr. Kelley points out several other benefits to BIS that were not mentioned in the study. For example, he says, a growing number of anesthesiologists use brain-monitoring information to adjust the dose of anesthetic medication to the patient's unique responses.

Nathan Hall

Colonoscopy patients who received a self-administered mixture of propofol and remifentanil were sedated in half the time and were able walk sooner in the PACU when compared to patients who received midazolam and fentanyl, according to a study published in the February issue of Anesthesia and Analgesia.

Patients who received propofol and remifentanil were up and walking without assistance in an average of five minutes for two reasons, says study co-author Jeff E. Mandel, MD, MS, clinical associate professor of anesthesiology and critical care at the University of Pennsylvania School of Medicine in Philadelphia. First, because each patient controlled the amount of sedation, there was less chance of oversedation. "Patients drop back [on self-dosing] towards the end of the procedure," says Dr. Mandel. Second, the small dose of the opioid remifentanil, which has a quick onset, allowed the anesthesiologist to decrease the dosage of propofol.

Researchers at the University of Pennsylvania studied 50 colonoscopy patients. Each received a bolus of propofol-remifentanil or midazolam-fentanyl and was then allowed to control the sedation. Patients who received the propofol-remifentanil mix were sedated in an average of 3.4 minutes, compared to 7.6 minutes for the midazolam-fentanyl group. Average recovery time was 4.9 minutes for the propofol-remifentanil group, compared to 36.4 minutes for the midazolam-fentanyl group. For the propofol-remifentanil group, the recovery time was actually shorter than the procedure room time, says Dr. Mandel.

The combination of propofol and remifentanil, however, can cause respiratory depression, researchers say. In two of the cases studied, the anesthesiologist had to intervene. Otherwise, the cocktail shows promise of increasing efficiencies for anesthesia care monitored by an anesthesiologist, says Dr. Mandel.

Kent Steinriede

A nurse who tampered with fentanyl vials put 355 patients in jeopardy, according to officials at Immanuel St. Joseph's Hospital in Mankato, Minn. The trouble began on Feb. 25, when empty vials of the drug were discovered in a wastebasket. An internal investigation led hospital officials to a nurse who apparently opened new vials of the drug, withdrew the contents and filled the empty vials with sterile saline solution from pre-filled syringes. The nurse, who reportedly acted alone, was suspended immediately and is no longer working at the hospital.

After identifying the nurse, hospital officials shifted their investigation to the hundreds of patients who had received sedation for procedures performed in the facility's cardiac catheterization, endoscopy and radiology labs. Saline solution is harmless, but using the solution in place of fentanyl could have presented patients with inadequate sedation and pain management, say hospital officials.

A review of patient records, however, did not reveal cases of excessive pain or insufficient sedation. Hospital administrators also consulted with the Minnesota Department of Health to determine that patients were at low risk of related complications and that medical follow-up was unnecessary. The hospital did send letters to each patient, apologizing for the mishap and inviting them to contact the facility with questions or concerns via an incident-specific hotline.

Daniel Cook