Cardiovascular effects of intravenous propofol administered at two infusion rates: a transthoracic echocardiographic study.
We assessed the haemodynamic changes after a propofol infusion at two rates in low-risk unpremedicated patients (ASA I-II). To determine contractility changes and loading conditions, we measured the ejection fraction, end-systolic quotient and fractional shortening on transthoracic echocardiograms. We studied 40 patients undergoing peripheral neurosurgical procedures under general anaesthesia induced by propofol alone (total dose 2.5 mg.kg-1). Patients were randomly assigned to receive propofol at an infusion rate of 10 mg.s-1; or 2 mg.s-1. Haemodynamic data were recorded simultaneously immediately before propofol infusion, at the end of infusion, and 5 and 10 min after the infusion ended. The higher infusion rate induced a larger decrease in mean arterial pressure than the lower infusion rate (- 20% vs. - 10% from baseline, p = 0.01). In both groups, global and segmental ventricular function remained unchanged throughout the study. In both groups, there were markedly reduced end-systolic quotients--presumably related to diminished afterload, and in the higher infusion-rate group a significant reduction in fractional shortening--presumably related principally to diminished preload.
Bilotta
F
F
Department of Anaesthesia and Intensive Care, Policlinico Umberto I, University La Sapienza, Rome, Italy. bilotta@tiscalinet.it
Fiorani
L
L
La Rosa
I
I
Spinelli
F
F
Rosa
G
G
D000328:Adult; D000768:Anesthesia, General; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004334:Drug Administration Schedule; D004452:Echocardiography; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D019635:Neurosurgical Procedures; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*
D018686:Anesthetics, Intravenous; D015742:Propofol