title: Transient hyperdynamic response associated with controlled hypocapneic hyperventilation during sevoflurane-nitrous oxide mask induction in adults.
abstract: We assessed hemodynamic variables during sevoflurane face mask anesthetic induction in female ASA physical status I or II patients. Anesthesia was induced with a single-breath inhalation method with 8% sevoflurane in 50% nitrous oxide in oxygen. Thirty patients were randomized either to breathe spontaneously (SB group, n = 15) or to receive controlled ventilation (CV group, n = 15) for 6 min after the loss of consciousness. Noninvasive blood pressure and heart rate (HR) were recorded at 1-min intervals. Mean +/- SD HR increased from 83+/-18 to 112+/-24 bpm at 4 min in the CV group (P < 0.001 between groups and within group compared with baseline). Mean arterial pressure increased from 97+/-9 to 106+/-26 mm Hg at 4 min in the CV group, which was significantly higher than that in the SB group (P < 0.01). In the SB group, mean arterial pressure decreased significantly, from 96+/-8 to 78+/-13 mmHg, at 6 min (P < 0.001), and HR remained unchanged. Therefore, hyperventilation should be avoided during the induction of sevoflurane anesthesia via a mask.
  
  
  CONCLUSIONS
  In this randomized, prospective study, we found that controlled hypocapneic hyperventilation delivered manually during sevoflurane/ N2O/O2 mask induction was associated with a significant transient hyperdynamic response. This kind of hemodynamic arousal can be detrimental to many patients and can be avoided by conducting sevoflurane mask induction with unassisted spontaneous breathing.
authors.affiliation: Department of Obstetrics and Gynaecology, Helsinki University Central Hospital, Finland. anne.vakkuri@huch.fi
authors.forename: A P
authors.initials: AP
authors.lastname: Vakkuri
authors.forename: L
authors.initials: L
authors.lastname: Lindgren
authors.forename: K T
authors.initials: KT
authors.lastname: Korttila
authors.forename: A M
authors.initials: AM
authors.lastname: Yli-Hankala
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics; D006801:Humans; D017214:Laryngeal Masks; D008738:Methyl Ethers; D008875:Middle Aged; D009609:Nitrous Oxide; D011446:Prospective Studies; D012121:Respiration, Artificial; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D002245:Carbon Dioxide; D000077149:Sevoflurane; D009609:Nitrous Oxide