title: Noninvasive ICG clearance test for estimating hepatic blood flow during halothane and isoflurane anaesthesia.
abstract: The purpose of this study was to estimate hepatic blood flow during halothane (HAL) or isoflurane (ISO) anaesthesia with the noninvasive indocyanine green (ICG) clearance test. Twenty-four ASA status I adult patients, scheduled for elective surgery without liver disease, were allocated into four groups. Before surgery, ICG clearance was measured twice in patients before and after 1, 2 MAC HAL-N2O, 1 and 2 MAC ISO-N2O anaesthesia by ICG clearance meter (Sumitomo Electronics, Japan). This method eliminates the blood sampling and delay of the conventional ICG test. The ICG clearance is displayed in two indices: K (ICG disappearance rate) and R15 (ICG retention rate 15 min after 0.5 mg.kg-1 ICG injection). Indirect blood pressure and heart rate were measured simultaneously. Mean arterial pressure (MAP) decreased by 27, 22 and 29% with 2 MAC HAL-N2O, and with 1 and 2 MAC ISO-N2O groups, respectively (P < 0.05). The ICG clearance was less (P < 0.05) in the 2 MAC HAL-N2O group (K, 0.087 min-1) than with either awake (K, 0.131 min-1) or other groups (K, 0.114 and 0.144 min-1, in the 1 MAC HAL and ISO-N2O groups, respectively) in spite of a similar degree of the depletion of MAP in 2 MAC ISO-N2O group (K, 0.124 min-1). We conclude that isoflurane has a more favourable effect on liver circulation than does halothane.
authors.affiliation: Department of Anesthesiology, School of Medicine, Sapporo Medical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kanaya
authors.forename: H
authors.initials: H
authors.lastname: Iwasaki
authors.forename: A
authors.initials: A
authors.lastname: Namiki
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D017558:Elective Surgical Procedures; D006221:Halothane / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007208:Indocyanine Green / Q000032:analysis / Q000493:pharmacokinetics; D007530:Isoflurane / Q000008:administration & dosage / Q000494:pharmacology*; D008102:Liver Circulation / Q000187:drug effects*; D008875:Middle Aged; D009609:Nitrous Oxide; D013990:Tidal Volume; D014851:Wakefulness
chemical_list: D002245:Carbon Dioxide; D007530:Isoflurane; D007208:Indocyanine Green; D009609:Nitrous Oxide; D006221:Halothane