The hemodynamic changes by different end-tidal CO2 under anesthesia using sevoflurane-N2O. |
Si Young Ok, Hea Rim Chun, Young Hee Baek, Sang Ho Kim, Soon Im Kim, Sun Chong Kim, Wook Park, Kyung Yul Hur |
1Department of Anesthesiology and Pain Medicine, Soonchunhyang University Hospital, Seoul, Korea. syok2377@naver.com 2Department of Surgery, Soonchunhyang University Hospital, Seoul, Korea. |
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Abstract |
BACKGROUND Hypercapnia augments cardiac output and can initiate a sympathetically mediated release of catecholamines to increase cardiac output. Many studies of hemodynamic changes by hypercapnia under general anesthesia with inhalation anesthetics besides sevoflurane. This study examined the hemodynamic changes by increasing end-tidal carbon dioxide (EtCO2) under sevoflurane-N2O anesthesia. METHODS Twenty patients were enrolled in the study. We studied stable, mechanically ventilated patients under general anesthesia maintained with O2 2 L/min - N2O 2 L/min - sevoflurane (1.5-2.5 vol%). Hypercapnia were obtained by reducing tidal volume and respiratory rate. EtCO2 was adjusted to 30, 40, 50 mmHg with each concentration maintained for 15 min. Global hemodynamic variables were monitored with a pulmonary artery catheter. RESULTS There were no changes in mean arterial pressure or heart rate by hypercapnia. Acute moderate hypercapnia increased cardiac output (4.9 +/- 1.7, 5.5 +/- 1.7, 6.2 +/- 2.1 L/min; P < 0.05), cardiac index (3.0 +/- 0.9, 3.4 +/- 0.9, 3.8 +/- 1.1 L/min/m2; P < 0.05), pulmonary artery pressure (16.9 +/- 3.7, 19.6 +/- 4.2, 23.0 +/- 4.7 mmHg), but did not decrease systemic vascular resistance (1,558.3 +/- 500.4, 1,423.5 +/- 678.6, 1,156.8 +/- 374.0 dynes.sec/cm5; P > 0.05). CONCLUSIONS When we changed patient EtCO2 to 30, 40, and 50 mmHg, there were no changes in mean arterial blood pressure and heart rate, but systemic vascular resistance decreased, and cardiac output, cardiac index and mean pulmonary arterial pressure increased significantly. |
Key Words:
Hemodynamic variables; Hypercapnia; Sevoflurane; Pulmonary artery catheter |
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