Changes in onset time of rocuronium in patients pretreated with ephedrine and esmolol – the role of cardiac output
We investigated the hypothesis that manipulation of cardiac output (CO) with esmolol (Es) or ephedrine (E) affects the onset time of rocuronium. Methods:
Following anesthesia induction, 33 patients received E (70 µg kg−1), Es (500 µg kg−1) or placebo (P) 30 s before rocuronium (0.6 mg kg−1) administration. Cardiac output was measured non-invasively after intubation every 3 min. The interval from the end of rocuronium administration to the disappearance of all twitches was considered to be the onset time. Results:
Onset time was shorter after E (52.2 ± 16.5 s) and longer after Es (114.3 ± 11.1 s) compared with P (87.4 ± 7.3 s) (P < 0.0001). Cardiac output increased (P < 0.05) in group E for 15 min after rocuronium. In group Es, CO decreased (P < 0.05) at 3 and 6 min. Cardiac output was higher in group E vs. group Es, 3–6 min post administration of rocuronium (P=0.015). Conclusion:
Pretreatment with E or Es appears to affect the onset time of rocuronium by altering CO as measured with the NICOTM (Non-Invasive Cardiac Output) monitor (Novametrix Medical Systems Inc., Willingford, CO).
Document Type: Research Article
Affiliations: 1: Department of Anesthesia Wolfson Medical Center, Holon, affiliated to the Sackler School of Medicine, Tel Aviv, Israel, OUTCOMES RESEARCH 2: Department of Anesthesiology, University of Texas Medical School, Houston, TX, OUTCOMES RESEARCH 3: Department of Anesthesiology, 4: Department of Anesthesiology, and 5: Department of Anesthesiology, University of Texas Medical School, Houston, TX
Publication date: October 1, 2003