The dose effect of ephedrine on the onset time of vecuronium.

UNLABELLED: A small dose of ephedrine decreases the onset time of rocuronium and cisatracurium; however, ephedrine might be associated with adverse hemodynamic effects. The appropriate dose of ephedrine has not been determined. We, therefore, studied 120 patients anesthetized with fentanyl 2 microg/kg and propofol 2-2.5 mg/kg who were randomly divided to receive either ephedrine (30, 70, or 110 microg/kg) or saline. During propofol anesthesia, the neuromuscular block was monitored by mechanomyography by using submaximal current of train-of-four stimulation every 10 s. To determine cardiac output, a transcutaneous Doppler probe was placed externally at the suprasternal notch. Tracheal intubation was performed by a blinded investigator at 2 min after vecuronium. Neuromuscular block, intubating conditions, and hemodynamic effects were measured during the induction of anesthesia. Both ephedrine 70 and 110 microg/kg improved intubating conditions at 2 min after vecuronium; however, 110 microg/kg was associated with adverse hemodynamic effects. We conclude that ephedrine 70 microg/kg given before the induction of anesthesia improved intubating conditions at 2 min after vecuronium, probably by increased cardiac output without significant adverse hemodynamic effects. IMPLICATIONS: Ephedrine 70 microg/kg given before the induction of anesthesia improved tracheal intubating conditions at 2 min after vecuronium by increased cardiac output without significant adverse hemodynamic effects.

The duration of immobilization causes the changing pharmacodynamics of mivacurium and rocuronium in rabbits.

In the clinical setting, in patients with a cast, it is not known whether the monitoring of the neuromuscular paralysis induced by either mivacurium or rocuronium in the contralateral limb is the correct interpretation. We compared the dose-response relationships and the neuromuscular blocking effects of mivacurium and rocuronium in 56 anesthetized rabbits immobilized in a plaster cast for 2, 4, and 6 wk. Train-of-four stimuli were simultaneously applied every 10 s to both common peroneal nerves, and the force of contraction of both tibialis anterior muscles was measured. Immobilization was associated with a rightward shift of the mivacurium and rocuronium dose-response curves after the duration of the immobilized limb, whereas no shift occurred in the contralateral limb. The 50% effective dose values for 0, 2, 4, and 6 wk of immobilization in the immobilized limb of mivacurium were 15.1 +/- 1.4, 18.2 +/- 1.5, 21.5 +/- 1.9, and 27.8 +/- 2.5 microg/kg, respectively, and they were unchanged in the contralateral limb. The calculated 50% effective dose values for the correspondence of rocuronium were 48.1 +/- 4.1, 56.2 +/- 4.2, 64.8 +/- 4.9, and 75.1 +/- 5.5 microg/kg, respectively, and they were unchanged in the contralateral limb. The rabbits receiving mivacurium and rocuronium had a significantly accelerated recovery from neuromuscular blockade compared with the placebo group in the immobilized limb after the immobilized duration, whereas there were no differences in the contralateral limb. The results of the present study showed that immobilization disuse atrophy produced by casting led to the development of resistance to both mivacurium and rocuronium; however, no resistance was shown in the contralateral limb. The peripheral nerve stimulator could be applied on the nonimmobilized limb, which might be associated with a normal recording if either mivacurium or rocuronium was used as neuromuscular relaxants.

Capsicum plaster at the korean hand acupuncture point reduces postoperative nausea and vomiting after abdominal hysterectomy.

UNLABELLED: Postoperative nausea and vomiting (PONV) are still common and distressing problems after general anesthesia, especially in patients undergoing abdominal hysterectomy. We studied a nonpharmacological therapy of PONV-capsicum plaster (PAS)-at either the Korean hand acupuncture point K-D2 or the Chinese acupuncture point Pericardium 6 (P6) of both hands. One-hundred-sixty healthy patients were included in a randomized, double-blinded study: 60 patients were in the control group, 50 patients were in the K-D2 group, and 50 patients were in the P6 group. PAS was applied at the K-D2 point in the K-D2 group and at the P6 point in the P6 group, whereas in the control group, an inactive tape was fixed at the K-D2 point of both hands. The PAS was applied before the induction of anesthesia and removed at 8 h after surgery. The incidence of PONV and the need for rescue medication were evaluated at predetermined time intervals. In the treatment group, the incidence of vomiting was significantly less (22% for the K-D2 group and 26% for the P6 group) than in the control group (56.7%) at 24 h after surgery (P < 0.001). The need for rescue antiemetics was significantly less in the treatment groups compared with the control group (P < 0.001). We conclude that PAS at the Korean hand acupuncture point K-D2 was an effective method for reducing PONV, as was PAS at the P6 acupoint, after abdominal hysterectomy. IMPLICATIONS: Capsicum plaster at either the Korean hand acupuncture point K-D2 or the Pericardium 6 acupoint reduces postoperative nausea and vomiting in patients undergoing abdominal hysterectomy.