[Behavior of adrenaline, noradrenaline, blood pressure and heart rate in intubation in relation to different doses of fentanyl].

In 24 patients undergoing ENT surgery the reactions of blood pressure, heart rate and plasma catecholamines were studied during standardized induction of anaesthesia as well as after additional fentanyl administration of 0.1 or 0.2 mg before intubation. In the control group (n = 8) six measurements were performed, i.e. one minute before and after the administration of the drugs for induction, as well as immediately after the insertion of the laryngoscope and one minute after intubation. In the reference groups two measurements were performed: before induction of anaesthesia and one minute after intubation, in the period of maximal circulatory reaction. 0.1 or 0.2 mg were administered in the fentanyl groups (n = 8 in each) after precurarization before injecting thiopentone. The blood pressure was measured by oscillometry, the heart rate was recorded by an ECG monitor, and the plasma catecholamines were determined by a radio-enzymatic method. In the control group without fentanyl only a rise in heart rate was observed in the induction period until laryngoscopy. After the insertion of the laryngoscope the increase in systolic and diastolic blood pressures, heart rate and plasma noradrenaline levels were marked. One minute after intubation these parameters rose again. The adrenaline concentration hardly changed during the entire period of induction. The administration of 0.1 mg fentanyl proved to be insufficient to depress the sympathoadrenergic reaction during intubation. Although plasma catecholamines did not rise, a marked increase in blood pressure and heart rate could not be avoided. The difference compared to 0.2 mg fentanyl was significant in the parameters blood pressure and heart rate (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)