Optimal Dose of Remifentanil to Suppress Cardiovascular Responses to Laryngoscopic Endotracheal Intubation / 대한마취과학회지

BACKGROUND: Laryngoscopic tracheal intubation causes acute hemodynamic changes such as hypertension and tachycardia. Adjuvant opioids during induction have been used to attenuate such responses. The aim of this study was to determine the optimal dose of bolus remifentanil, a newly developed ultra short acting opioid, to suppress cardiovascular responses immediately after laryngoscopic endotracheal intubation in patients anesthetized with N2O-O2-sevoflurane. METHODS: Sixty ASA I or II patients who requiring endotracheal intubation were randomly allocated to one of the four groups; C, R0.5, R1, and R2. Each group received normal saline, 0.5, 1, or 2microgram/kg of remifentanil respectively. Predetermined drugs for each group were administered over 30 seconds after induction of anesthesia with thiopental, rocuronium and 2 vol% of sevoflurane with 50% nitrous oxide. Laryngoscopic endotracheal intubation was carried out 60 seconds after the study drug administration. Mean arterial pressure (MAP) and heart rate (HR) were recorded at pre-anesthesia (PA), pre-intubation (PI) and during 5 minutes after intubation (IT-1 to IT-5). Statistical analysis was done for comparison of time and dose dependent changes among the groups. RESULTS: Baseline values were similar among the groups. IT-1 values did not change compared to PI values in R1 and R2. However, MAP and HR in R2 were significantly lower than PA values during post-intubation period. CONCLUSIONS: Bolus injection of 1microgram/kg of remifentanil blocks MAP and HR elevation after laryngoscopic endotracheal intubation without adverse effects in patients under N2O-O2-sevoflurane anesthesia.

A Comparison of Femoral and Radial Artery Pressure during an Adult Liver Transplantation / 대한마취과학회지

BACKGROUND: The radial artery pressure is known to differ from central arterial pressure in normal patients (distal pulse amplification) and in the early postcardiopulmonary bypass period. We assumed that there may be a change in the normal relationship between central and peripheral arterial pressure in patients with hepatic failure due to an arterio-venous shunt caused by vasodilation and a complex surgical procedure with major vessel clamping. This study was done to examine the adequacy of the radial artery as a site for blood pressure monitoring in liver transplantation (TPL). METHODS: We investigated when the pressure gradient developed and what mechanism could be responsible by comparing femoral to radial artery pressure in 11 patients undergoing liver transplantation. Radial and femoral artery pressures, systemic vascular resistance, cardiac output and temperature were compared during surgery in all 11 patients. Additionally measurements included pH, PaO2, PaCO2, central venous pressure, pulmonary artery pressure and mixed venous oxygen saturation. RESULTS: The femoral artery systolic pressure was higher than the corresponding radial artery pressures during the operation. Although not statistically significant, the radial mean and diastolic artery pressures were lower than corresponding the femoral artery pressure. CONCLUSIONS: Radial artery systolic pressures underestimate the femoral artery pressure when undergoing a liver TPL. Failure to recognize these effects on pressure recordings can lead to inappropriate patient management decisions.