The effect of phenylephrine on the onset time of rocuronium.
10.4097/kjae.2010.59.4.244
- Author:
Young Ju WON
1
;
Yang Sik SHIN
;
Ki Young LEE
;
Woon Young CHO
Author Information
1. Department of Anesthesiology and Pain Medicine & Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea. ysshin@yuhs.ac
- Publication Type:Original Article ; Randomized Controlled Trial
- Keywords:
Onset time;
Phenylephrine;
Rocuronium
- MeSH:
Adult;
Androstanols;
Anesthesia;
Arterial Pressure;
Blood Pressure;
Cardiac Output;
Ephedrine;
Fentanyl;
Heart Rate;
Humans;
Intubation;
Muscles;
Phenylephrine;
Propofol;
Vasoconstriction
- From:Korean Journal of Anesthesiology
2010;59(4):244-248
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Several studies have demonstrated that ephedrine shortens the onset time of muscle relaxants, and it does so probably by increasing the cardiac output. However, elevation of the systemic blood pressure through alpha adrenergic stimulation via ephedrine may affect the onset of muscle relaxants during the induction of anesthesia. We investigated the effect of phenylephrine, which is a selective alpha-1 agonist, on the onset time of rocuronium and the intubating conditions in adults after the administration of propofol. METHODS: Sixty-four patients were randomly assigned to two groups. Phenylephrine (0.9 microgram/kg) (P group) or the same volume of saline (S group) was injected before rocuronium (0.6 mg/kg) administration. Anesthesia was induced with fentanyl 2 microgram/kg and propofol 2 mg/kg. The onset time was defined as the time from the end of rocuronium injection to the time when a single twitch height gets to 0% or the minimum level. A well-trained anesthesiologist who was 'blinded' to the treatment groups evaluated the intubating conditions. The mean arterial pressure and heart rate were recorded before induction, before intubation, immediately after intubation and 1 minute and 2 minutes after intubation. RESULTS: The onset time was 84 +/- 18 sec in the P-group and 72 +/- 14 sec in the S-group. There was no difference of the intubating conditions, the mean arterial pressure and the heart rate between the two groups. CONCLUSIONS: A small dose of phenylephrine, which has a limited effect on blood pressure, delayed the onset time of rocuronium after the administration of propofol, and the vasoconstriction effect of phenylephrine may affect the prolongation of the rocuronium onset time at the induction of anesthesia with using propofol.
