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. ⋯ 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.
A P Vakkuri, L Lindgren, K T Korttila, and A M Yli-Hankala.
Department of Obstetrics and Gynaecology, Helsinki University Central Hospital, Finland. anne.vakkuri@huch.fi
Anesth. Analg. 1999 Jun 1; 88 (6): 1384-8.
UnlabelledWe 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.ImplicationsIn 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.