Effect of induction of general anesthesia with propofol and fentanyl on hemodynamic response

Background: Induction of general anesthesia with propofol and fentanyl is frequently associated with changes in arterial blood pressure and heart rate. At present, there are no clinical studies investigating the relation between baseline cardiac autonomic tonus and cardiovascular instability after induction of general anesthesia with propofol and fentanyl.

Material and methods: A randomized prospective study was performed with approval of Ethic Committee. Written informed consent was obtained from all patients. We enrolled in the study 47 ASA physical status I–II patients scheduled for elective surgical procedures. Heart rate variability by Holter ECG, arterial blood pressure (systolic, diastolic, mean), and heart rate were measured at baseline, after premedication, as well as after induction of general anesthesia with propofol 2.5mg/kg and fentanyl 1.0 mkg/kg.

Results: our research revealed that increased baseline cardiac parasympathetic tonus was a risk factor for development of sinus bradycardia (OR = 21.0 (95%CI 3.9-112.8, p<0.0002) and sinus bradycardia associated with arterial hypotension (OR = 19.2 (95%CI 4.1-88.6, p<0.0001).

Conclusions: Induction of general anesthesia with propofol and fentanyl was associated frequently with arterial hypotension and sinus bradycardia. Increased cardiac parasympathetic tonus at rest represents a risk factor for development of arterial hypotension and sinus bradycardia after administration of propofol and fentanyl for induction of general anesthesia.