Ephedrine, but not phenylephrine, increases bispectral index values during combined general and epidural anesthesia

• Published in: Anesthesia and analgesia Vol. 97; no. 3; pp. 780 - 784
• Main Authors: ISHIYAMA, Tadahiko, OGUCHI, Takeshi, IIJIMA, Tetsuya, MATSUKAWA, Takashi, KASHIMOTO, Satoshi, KUMAZAWA, Teruo
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott 01.09.2003
• Subjects: Aged; Anesthesia; Anesthesia, Epidural; Anesthesia, General; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Blood Pressure - drug effects; Electroencephalography - drug effects; Ephedrine - pharmacology; Female; General anesthesia. Technics. Complications. Neuromuscular blocking. Premedication. Surgical preparation. Sedation; Heart Rate - drug effects; Humans; Male; Medical sciences; Middle Aged; Monitoring, Intraoperative; Phenylephrine - pharmacology; Vasoconstrictor Agents - pharmacology; Volatile compound; Human; Agonist; Associated technique; Antihypotensive agent; Ephedrine; α1-Adrenergic receptor; General anesthesia; Electroencephalography; Ropivacaine; Sympathomimetic; Spectral analysis; Local anesthetic; Sevoflurane; Regional anesthesia; General anesthetic; Extradural administration; Phenylephrine; Vasoconstrictor agent; Organic amide; Halogen Organic compounds
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/01.ANE.0000073355.63287.E4

Ephedrine and phenylephrine are used to treat hypotension during combined general and epidural anesthesia, and they may change anesthetic depth. In the current study, we evaluated the effects of ephedrine versus phenylephrine on bispectral index (BIS) during combined general and epidural anesthesia. After injection of ropivacaine through the epidural catheter, general anesthesia was induced with propofol and vecuronium, and was maintained with 0.75% sevoflurane. Approximately 10 min after the intubation, BIS was recorded as a baseline value. Patients with decreases in arterial blood pressure <30% of the preanesthetic values were defined as control group (n = 9). Patients who had to be treated for larger decreases in arterial blood pressure were randomly assigned to receive ephedrine 0.1 mg/kg (n = 17) or phenylephrine 2 micro g/kg (n = 17). BIS values were recorded at 1-min intervals for 10 min. BIS in the ephedrine group was significantly larger from 7 to 10 min than that in the control and phenylephrine groups (P < 0.05). Seven patients in the ephedrine group had BIS >60, whereas no patient in the control and phenylephrine groups had BIS >60 (P < 0.005). Ephedrine, but not phenylephrine, increased BIS during general anesthesia combined with epidural anesthesia.