Comparison between End - Tidal Carbon Dioxide Tension and Arterial Carbon Dioxide Tension during Cardiopulmonary Bypass / 대한마취과학회지

The changes in arterial carbon dioxide tension (PaCO2) during cardiopulmonary bypass reflect changes of temperature and gas flow through an oxygenator. The changes in PaCO2 can be reduced through the frequent analysis of arterial blood gases and subsequent adjustment of total gas flow and CO2 concentration in the gas flow or both. Utilizing a capnometer (CAPNOMAC AGM-103. Datex), we compared end-tidal carbon dioxide tension (PetCO2) from the capnometer with temperature corrected PaCO2 during cardiopulmonary bypass. One end of the sampling port of the capnometer was incorporated into the prime port of the arterial reservoir in a bubbling type oxygenator (William-Harvey). When arterial reservoir temperatures of the oxygenator were 30 degrees C and 35 degrees C, PetCO2 from the capnometer was recorded and two arterial blood gas samplings were done at the same temperatures. The results were as follows: 1) The difference of PetCO2 and temperature corrected PaCO2 was below 3 mmHg in all cases. 2) The relationship between PetCO2 and temperature corrected PaCO2 was significantly linear. The results show that continuous monitoring of PetCO2, using a capnometer is useful to control the changes in PaCO2 during cardiopulmonary bypass.

Change of Internal Jugular Venous Oxygen Content during Hypotension in Halothane and Isoflurane Anesthesia / 대한마취과학회지

Autoregulation of cerebral blood flow is altered by volatile anesthetics and vasodilators such as nitroglycerin. Forty patients with cerebral aneurysm were anesthetized with halothane or isoflurane, and hypotension (mean arterial pressure: 55 mmHg) was induced with nitroglycerin. Blood gas analysis of radial artery and internal jugular vein during normotension and hypotension was performed. The results were as follows 1) There were no significant changes in juqular venous oxygen saturation, difference of arterial and venous oxygen content and extration rate of oxygen between normotension and hypotension. 2) There were no differences in SjvO2, CaO2, CjvO2, and O2ER between halothane and isoflurane. There is no possibility of cerebral ischemia in induced hypotension by nitroglycerin during halothane and isoflurane anesthesia.