Sevoflurane MAC and hemodynamics in pigs Otsuki DA et al. Table 2 - Hemodynamic data. CI (L/min/m2) HR (beat/min) MAP (mmHg) CVP (mmHg) MPAP (mmHg) PAWP (mmHg) SVRI (dynes.sec/cm5/m2) PVRI (dynes.sec/cm5/m2) LVSWI (gm-m/m2/beat) RVSWI (gm-m/m2/beat) SVI (mL/m2/beat) EDVI (mL/m2) Group Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris Sevo A Sevocris 0.5 MAC 5.5 (1.3) * 6.2 (0.7) * 129 (20) 138 (19) * 81 (15) * 90 (17) * 8 (2) 7 (2) * 23 (3) * 22 (3) * 11 (2) 11 (1) 1076 (211) 1080 (201) 171 (34) 153 (35) 41 (12) * 47 (13) * 8 (2) * 9 (1) * 44 (9) * 45 (6) 159 (33) 162 (30) 1.0 MAC 4.2 (0.8) 4.7 (1.1) 122 (17) 115 (15) 66 (7) 68 (10) 9 (2) 9 (1) 21 (2) 21 (3) 12 (2) 11 (1) 1106 (185) 1047 (260) 183 (30) 165 (41) 26 (6) 33 (6) 6 (1) 7 (2) 34 (5) 41 (8) 157 (52) 148 (19) CLINICS 2010;65(5):531-7 1.5 MAC 3.2 (1.0) * † 3.6 (1.2) * † 110 (16) * † 104 (13) † 45 (10) * † 52 (11) * † 9 (2) 10 (1) † 19 (3) * † 20 (3) † 12 (1) 12 (2) 959 (193) 187 (61) 184 (63) 13 (6) * † 20 (9) * † 4 (2) * † 5 (2) * † 28 (6) * † 34 (9) * † 156 (58) 146 (11) 896 (201) * † Mean (SD); CI=cardiac index; HR=heart rate; MAP=mean arterial pressure; CVP=central venous pressure; MPAP=mean pulmonary artery pressure; PCWP=pulmonary artery wedge pressure; SVRI=systemic vascular resistance index; PVRI=pulmonary vascular resistance index; LVSWI=left ventricular stroke work index; RVSWI=right ventricular stroke work index; SVI=stroke volume index; EDVI=right ventricular end-diastolic volume index. * P<0.05 compared to 1 MAC; † P<0.05 compared to 0.5 MAC. movement in response to the applied stimulus (Table 4). 6, 7, 14 The stimulus applied in our study was dewclaw clamping, which has been reported to be a supramaximal stimulus6 and which remained constant during the entire study. The site of stimulus was changed slightly between stimulations to prevent sensitization or desensitization to subsequent stimuli. In the study of Hecker,10 where the pigs had almost the same weight and were submitted to the same nociceptive stimulation as in the present study, the MAC was lower, which may have been due to the previous use of azaperone and propofol. Holmström and Åkeson,13 in animals weighing 20.1± 0.7 kg, obtained a MAC of 4.4 90 minutes after propofol administration, which is the same value reported in the present investigation. On the other hand, Moeser et al.,12 studying animals weighing 19 ±0.4 kg and with no other agent than sevoflurane, obtained a MAC of 3.5±0.17. In the present investigation, weight, age, sex, and stimuli were similar in both groups, demonstrating that the two anesthetics showed the same behavior with regard to MAC. The hemodynamic results are close to those described in the literature for sevoflurane. In healthy human volunteers and in dogs, the cardiac index, arterial pressure and pulmonary arterial pressure decrease in a dose-dependent manner.15,16 In infants, sevoflurane did not alter the cardiac index at any concentration compared to awake values but significantly decreased blood pressure and systemic vascular resistance compared to awake values at all concentrations.17 Special focus has been given to the effects of volatile anesthetics on heart rate because desflurane (and to a lesser extent isoflurane) can initiate major increases in heart rate that might predispose select patient populations to myocardial ischemia.18 The results with sevoflurane are conflicting, varying across different species, age groups and anesthetic techniques. Sevoflurane has not been associated with increases in heart rate in healthy volunteers, in patients,19 or in children.17 Bernard et al.,16 in dogs, noted 534 Copyright © 2010 CLINICS