Changes in Intra-cerebral Oxygenation During Intravenous and Inhalational Sedation: A Original Research Satoh Kenichi1,*, Chikuda Mami1, Ohashi Ayako1, Kumagai Miho2, Sato Masahito1, Joh Shigeharu1 1Department of Reconstructive Oral and Maxillofacial Surgery, Division of Dental Anesthesiology, School of Dentistry, Iwate Medical University, 1-3-27 Chuo-dori, Morioka, Iwate, 020–8505, Japan 2Department of Developmental Oral Health Science, Division of Special Care Dentistry, School of Dentistry, Iwate Medical University, 1-3-27 Chuo-dori, Morioka, Iwate, 020–8505, Japan *Address for Correspondence: Kenichi Satoh, Department of Reconstructive Oral and Maxillofacial Surgery, Division of Dental Anesthesiology, School of Dentistry, Iwate Medical University, 1.3.27 Chuo.dori, Morioka, Iwate 020.8505, Japan. Tel: +81.19.6515111 (ext. 4331), Fax: +81.19.6520756. E.mail: satoken@iwate.med.ac.jp
Online published on 5 October, 2015. Abstract Background Although sedatives such as midazolam or nitrous oxide (N2O) are administered to dental patients, the effects of these drugs on intra-cerebral oxygenation are not well-known. Aims We investigated the effects of intravenous midazolam or inhalational N2O on intra-cerebral oxygenation using near-infrared spectroscopy. Setting and Design University hospital, prospective. Materials and Methods During intravenous sedation, volunteers received supplemental oxygen through nasal cannula at 3 L/min for 10 min (control group). Midazolam (0.05 mg/kg) was then injected intravenously with flumazenil (20 mg) injected 30 min later. In the inhalational sedation study, volunteers lay quietly for 10 min receiving 100% oxygen, then received N2O via nasal mask at concentrations of 10%, 20%, and 25% for 5 min; 30% for 20 min; and supplemental oxygen at 100% for 15 min after N2O was discontinued. Statistical Analysis Intra-group comparisons were made using one-way analysis of variance for repeated measures followed by Dunnett's test for multiple comparisons. Differences were considered statistically significant at P < 0.05. Results During intravenous sedation, oxyhemoglobin increased 10 min after midazolam administration, and total hemoglobin increased slightly until 20 min after flumazenil administration, followed by a decrease. During inhalational sedation, oxyhemoglobin increased until 5 min after starting N2O, and total hemoglobin increased until 5 min after starting N2O, followed by a decrease. Conclusions Midazolam and N2O influenced intra-cerebral oxygenation during intravenous or inhalational sedation. Cerebral blood flow increased with intravenous sedation when midazolam was administered once at a dose of 0.05 mg/kg and with inhalational sedation when N2O was supplied at a concentration of 25–30%. Top Keywords Inhalational sedation, intra-cerebral oxygenation, intravenous sedation, oxyhemoglobin, total hemoglobin. Top |