The effect of phenylephrine on the onset time of rocuronium

Abstract

BackgroundSeveral 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 α 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 α-1 agonist, on the onset time of rocuronium and the intubating conditions in adults after the administration of propofol.MethodsSixty-four patients were randomly assigned to two groups. Phenylephrine (0.9 µg/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 µg/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.ResultsThe 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.ConclusionsA 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.

Pharmacological Interventions for Acceleration of the Onset Time of Rocuronium: A Meta-Analysis

“…In the end, 43 qualified studies (2465 patients) were included in this meta-analysis. Sixteen drugs with different combinations of intervention techniques were studied to affect the onset time of rocuronium: non-depolarizing muscle relaxants priming [17] – [30] ; ephedrine [31] – [35] , phenylephrine [36] , magnesium sulphate (MgSO4) [22] , [37] – [39] , suxamethonium [40] , [41] , lidocaine [42] – [44] , midazolam [45] and esmolol [31] , [35] pretreatments; rocuronium admixed with sodium bicarbonate [46] , [47] , mivacurium [48] – [54] and cisatracurium [55] ; rocuronium priming with pretreatments of thiopentone [24] , MgSO4 [22] and ketamine [29] , effects of chronic anticonvulsant therapy [56] – [58] ( Table 1 ). Intervention techniques mainly included non-depolarizing muscle relaxants priming, drug pretreatments, drugs mixed with rocuronium, and chronic anticonvulsant therapy.…”

Resistance to non-depolarizing neuromuscular blocking agents

“…[9] .It has been reported that the action expression time of rocuronium is shortened when phenylephrine, an alpha-adrenergic agonist, is administered. [10] In the case 1, the patient was being administered with ephedrine, phenylephrine and norepinephrine due to the hemodynamic instability and smoking, and with alpha-adrenergic antagonist for the treatment of benign prostate hyperplasia. It is thought to be also important to consider whether these medications can affect rocuronium.…”

EFEK PEMBERIAN KETAMIN DOSIS 0,5 mg/kgbb TERHADAP ONSET BLOKADE NEUROMUSKULAR OLEH ATRAKURIUM

“…Para peneliti telah menyarankan bahwa pelumpuh otot non depolarisasi dapat bekerja lebih cepat pada neuromuscular junction melalui peningkatan cardiac output dan aliran darah otot karena obat yang diinjeksikan melalui vena dapat mencapai neuromuscular junction lebih cepat. 4 Ketamin merupakan analog struktural dari phencyclidine. Obat ini digunakan untuk induksi anestesi intravena.…”