TY - JOUR
T1 - Protocol for the "Michigan Awareness Control Study"
T2 - A prospective, randomized, controlled trial comparing electronic alerts based on bispectral index monitoring or minimum alveolar concentration for the prevention of intraoperative awareness
AU - Mashour, George A.
AU - Tremper, Kevin K.
AU - Avidan, Michael S.
N1 - Funding Information:
Funding: Cerebral Function Monitoring grant by the Foundation for Anesthesia Education & Research and the American Society of Anesthesiologists (GAM, Principal Investigator); NIH KL2 Award (GAM, Principal Investigator) We would like to thank Amy Shanks, Dr. Sachin Kheterpal, Dr. Christopher Turner, Dr. Paul Picton, Dr. Satya Krishna Ramachandran, Christa Schuel-ler, Lisa Lau, and John Vandervest for their contributions to the study. We would also like to thank the anesthesia providers, anesthesia technicians, and biomedical engineers at the University of Michigan for their participation.
PY - 2009/11/5
Y1 - 2009/11/5
N2 - Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in the United States. The Bispectral Index monitor is an electroencephalographic method of assessing anesthetic depth that has been shown in one prospective study to reduce the incidence of awareness in the high-risk population. In the B-Aware trial, the number needed to treat in order to prevent one case of awareness in the high-risk population was 138. Since the number needed to treat and the associated cost of treatment would be much higher in the general population, the efficacy of the Bispectral Index monitor in preventing awareness in all anesthetized patients needs to be clearly established. This is especially true given the findings of the B-Unaware trial, which demonstrated no significant difference between protocols based on the Bispectral Index monitor or minimum alveolar concentration for the reduction of awareness in high risk patients. Methods/Design: To evaluate efficacy in the general population, we are conducting a prospective, randomized, controlled trial comparing the Bispectral Index monitor to a non-electroencephalographic gauge of anesthetic depth. The total recruitment for the study is targeted for 30,000 patients at both low and high risk for awareness. We have developed a novel algorithm that is capable of real-time analysis of our electronic perioperative information system. In one arm of the study, anesthesia providers will receive an electronic page if the Bispectral Index value is >60. In the other arm of the study, anesthesia providers will receive a page if the age-adjusted minimum alveolar concentration is <0.5. Our minimum alveolar concentration algorithm is sensitive to both inhalational anesthetics and intravenous sedative-hypnotic agents. Discussion: Awareness during general anesthesia is a persistent problem and the role of the Bispectral Index monitor in its prevention is still unclear. The Michigan Awareness Control Study is the largest prospective trial of awareness prevention ever conducted.
AB - Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in the United States. The Bispectral Index monitor is an electroencephalographic method of assessing anesthetic depth that has been shown in one prospective study to reduce the incidence of awareness in the high-risk population. In the B-Aware trial, the number needed to treat in order to prevent one case of awareness in the high-risk population was 138. Since the number needed to treat and the associated cost of treatment would be much higher in the general population, the efficacy of the Bispectral Index monitor in preventing awareness in all anesthetized patients needs to be clearly established. This is especially true given the findings of the B-Unaware trial, which demonstrated no significant difference between protocols based on the Bispectral Index monitor or minimum alveolar concentration for the reduction of awareness in high risk patients. Methods/Design: To evaluate efficacy in the general population, we are conducting a prospective, randomized, controlled trial comparing the Bispectral Index monitor to a non-electroencephalographic gauge of anesthetic depth. The total recruitment for the study is targeted for 30,000 patients at both low and high risk for awareness. We have developed a novel algorithm that is capable of real-time analysis of our electronic perioperative information system. In one arm of the study, anesthesia providers will receive an electronic page if the Bispectral Index value is >60. In the other arm of the study, anesthesia providers will receive a page if the age-adjusted minimum alveolar concentration is <0.5. Our minimum alveolar concentration algorithm is sensitive to both inhalational anesthetics and intravenous sedative-hypnotic agents. Discussion: Awareness during general anesthesia is a persistent problem and the role of the Bispectral Index monitor in its prevention is still unclear. The Michigan Awareness Control Study is the largest prospective trial of awareness prevention ever conducted.
UR - http://www.scopus.com/inward/record.url?scp=70749111068&partnerID=8YFLogxK
U2 - 10.1186/1471-2253-9-7
DO - 10.1186/1471-2253-9-7
M3 - Article
C2 - 19891771
AN - SCOPUS:70749111068
SN - 1471-2253
VL - 9
SP - 7
JO - BMC Anesthesiology
JF - BMC Anesthesiology
M1 - 7
ER -