The Hemodynamic Effects of Remifentanil as an Induction Agent in Cardiac Surgery

ABSTRACT

BACKGROUND: Remifentanil may be advantageous during induction of anesthesia in patient with heart disease because of rapid onset and hemodynamic stability. Some study reported that remifentanil showed complications such as profound bradycardia, severe hypotension and rigidity. The purpose of this study is to investigate the hemodynamic changes and side effects of remifentanil by using the methods of bolus administration during induction of anesthesia in cardiac surgery. METHODS: Fifty eight patients of ASA physical status 2~3 undergoing cardiac surgery were enrolled into 3 groups. We administered no remifentanil in Group A, 5microg/kg of remifentanil in Group B and 10microg/kg of remifentanil in Group C. After bolus administration of remifentanil over 30 sec, we infused 0.2microg/kg/min of remifentanil continuously. All group received continuous infusion of 100microg/ kg/min of propofol. After loss of consciousness, 0.15 mg/kg of vecuronium was administered. After the Bispectral index (BIS) value became lower than 60, intubation was done. Mean arterial pressure, heart rate, the incidence of cough, jaw and chest wall rigidity, and BIS value were measured initially and 1, 2, 3, 4, 5 minutes before intubation and 1, 2, 3, 4, 5 minutes after intubation. RESULTS: Mean arterial pressures of group B and C were significantly lower than those of group A (P < 0.05). Heart rate was similar among the groups. Group C showed a greater incidence of jaw rigidity (77%) compared with group A (35%) and group B (35%) (P < 0.05). The incidence of chest wall rigidity (66%) in group C was greater than group A (5%) and group B (15%) (P < 0.05). CONCLUSIONS: Remifentanil used as an induction agent (5microg/kg or 10microg/kg) may cause hypotension and jaw, chest wall rigidity with improper ventilation.