Determination of sevoflurane alveolar concentration for tracheal intubation with remifentanil, and no muscle relaxant

• Published in: Anaesthesia Vol. 55; no. 10; pp. 965 - 969
• Main Authors: Cros, A. M., Lopez, C., Kandel, T., Sztark, F.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-10-2000; Blackwell
• Subjects: Adolescent; Adult; Analgesics; Analgesics, Opioid; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Inhalation - administration & dosage; Anesthetics, Inhalation - pharmacokinetics; Biological and medical sciences; Blood Pressure - drug effects; Dose-Response Relationship, Drug; Drug Administration Schedule; General anaesthesia; General anesthesia. Technics. Complications. Neuromuscular blocking. Premedication. Surgical preparation. Sedation; Heart Rate - drug effects; Humans; Intubation, Intratracheal - methods; Logistic Models; Medical sciences; Methyl Ethers - administration & dosage; Methyl Ethers - pharmacokinetics; Middle Aged; opioid; Piperidines; Pulmonary Alveoli - metabolism; Remifentanil; Sevoflurane; volatile anaesthetics; Volatile compound; Human; General anesthesia; Opiates; Narcotic analgesic; Remifentanil; Sevoflurane; General anesthetic; Minimal alveolar concentration; Activity concentration relation; Intubation; Trachea; Halogen Organic compounds
• ISSN: 0003-2409; 1365-2044
• DOI: 10.1046/j.1365-2044.2000.01538.x

The sevoflurane alveolar concentration needed for tracheal intubation with remifentanil was studied in 26 adult patients premedicated with 100 mg hydroxyzine. Anaesthesia was induced with sevoflurane in oxygen. The concentration was determined by Dixon's up‐and‐down method. The first patient was tested at 4.5%. One minute after obtaining the preselected value, remifentanil 1 µg.kg−1 was injected for 60 s followed by an infusion of 0.25 µg.kg−1.min−1. Ventilation was then manually assisted for 2 min and tracheal intubation was attempted. Tracheal intubation conditions and responses to intubation were noted. Heart rate and mean arterial pressure were recorded before induction, before remifentanil injection, and before and 3 min after tracheal intubation. The concentration for acceptable intubating conditions was 2.5 ± 0.7%. From logistic regression, ED50 and ED95 were 2.0% (95% CI 1.3–2.5) and 3.2% (95% CI 2.6–5.6), respectively. With sevoflurane 2.5%, heart rate and mean arterial pressure decreased by 18% and 15%, respectively, after remifentanil administration and increased slightly after tracheal intubation.