title: Delayed respiratory depression following fentanyl anesthesia for cardiac surgery.
abstract: High-dose fentanyl anesthesia is widely used in cardiac surgery. Its immediate side-effects are well known. However, its late adverse effect manifested by extreme truncal rigidity, decreased chest wall compliance, hypoventilation, respiratory acidosis and hemodynamic instability is not sufficiently appreciated. Of 380 patients who underwent aortocoronary artery bypass under high-dose (100 micrograms/kg) fentanyl anesthesia, 29 (7.6%) developed the sudden onset of extreme thoracic and abdominal rigidity, leading to respiratory depression 2 to 6 h postoperative, after an apparently normal recovery from the anesthesia. In 15 patients, a high plasma level of fentanyl (5.2 to 7.8 ng/ml) correlated with the clinical events. Administration of naloxone or a muscle relaxant rapidly reversed this late complication of fentanyl, thought to be due to re-entry of fentanyl into plasma from deposits in adipose tissue, muscle and the GI tract, leading to a secondary peak in plasma fentanyl. It is more likely to be encountered when hypothermia, rewarming, and acidosis occur in the postoperative period. Awareness of this life-threatening complication is critical in patients undergoing surgery with fentanyl anesthesia.
authors.affiliation: Department of Cardiothoracic Surgery, Lady Davis Carmel Hospital, Israel.
authors.forename: J
authors.initials: J
authors.lastname: Caspi
authors.forename: J M
authors.initials: JM
authors.lastname: Klausner
authors.forename: T
authors.initials: T
authors.lastname: Safadi
authors.forename: R
authors.initials: R
authors.lastname: Amar
authors.forename: R R
authors.initials: RR
authors.lastname: Rozin
authors.forename: G
authors.initials: G
authors.lastname: Merin
mesh_terms: D000368:Aged; D000771:Anesthesia, Intravenous; D001026:Coronary Artery Bypass; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009127:Muscle Rigidity / Q000139:chemically induced / Q000188:drug therapy; D009270:Naloxone / Q000627:therapeutic use; D010366:Peak Expiratory Flow Rate; D012131:Respiratory Insufficiency / Q000139:chemically induced* / Q000188:drug therapy; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D009270:Naloxone; D005283:Fentanyl