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Changes in Intra-cerebral Oxygenation During Intravenous and Inhalational Sedation: A Original Research
Authors: Kenichi Satoh , Mami Chikuda , Ayako Ohashi , Miho Kumagai , Masahito Sato , Shigeharu Joh
Number of views: 447
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 oxygenationduring 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%