Target-controlled Infusion of Remifentanil during Propofol Induction in Hypertensive Patients: Effects of Three Different Remifentanil Concentrations on Hemodynamic Changes. |
Sang Hyun Lee, Jong In Han, Chi Hyo Kim |
Department of Anesthesiology and Pain Medicine, School of Medicine, Ewha Womans University, Seoul, Korea. hanji@ewha.ac.kr |
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Abstract |
BACKGROUND This study compared the hemodynamic effects of target-controlled infusion (TCI) of remifentanil (4, 5, or 6 ng/ml) during propofol induction in normotensive and hypertensive patients. It was also examined whether increasing the remifentanil concentrations might reduce propofol consumption at the loss of consciousness (LOC). METHODS Seventy five ASA 1 or 2 normotensive (N) and 75 ASA 2 hypertensive (H) patients were randomly allocated according to the remifentanil target effect-site concentration of 4, 5, 6 ng/ml (groups N4, N5, N6, H4, H5, H6 respectively). After the start of remifentanil TCI, when the target effect-site concentration of remifentanil had been reached, the TCI of propofol (4microgram/ml) was started. The effect-site concentration of propofol at LOC was recorded. When the target effect-site concentration of propofol was reached, 0.6 mg/kg of rocuronium was administered. Tracheal intubation was carried out after 2 minutes. The noninvasive blood pressure, heart rate (HR), bispectral index (BIS) and infused dose of remifentanil and propofol were recorded. RESULTS Groups H5, H6 and N6 resulted in significant decrease in blood pressure after intubation. In groups N4 and H4, clinically significant increases in HR (above 25% of the baseline) were observed at 1 minute after intubation.
The effect-site concentration of propofol at LOC was significantly lower in groups N6 and H6 compared to groups N4 and H4. CONCLUSIONS In hypertensive patients, a dosing requirement of lower effect-site concentration of 4 ng/ml remifentanil might be adequate during propofol induction. Increasing the remifentanil concentrations from 4 to 6 ng/ml may reduce the propofol requirements for hypnosis. |
Key Words:
hypertension; propofol; remifentanil; target-controlled infusion (TCI); tracheal intubation |
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