title: Changes in cardiac index and estimated systemic vascular resistance during induction of anaesthesia with thiopentone, methohexitone, propofol and etomidate.
abstract: Changes in cardiac index (CI) and estimated systemic vascular resistance (ESVR) were assessed non-invasively using pulsed Doppler ultrasound during induction of anaesthesia. Ninety-six ASA I patients were allocated randomly to one of four groups to receive alfentanil 8 micrograms kg-1 followed by a dose of thiopentone, methohexitone, propofol or etomidate sufficient to obtund the eyelash reflex. CI increased significantly by 8% 1 min after administration of both methohexitone (P < 0.05) and propofol (P < 0.05), returning to pre-induction values thereafter. CI increased after thiopentone but the increase was not statistically significant. There was a significant decrease in CI of 16% after induction with etomidate (P < 0.001). ESVR decreased significantly from pre-induction values by 18% after methohexitone (P < 0.001) and 23% after propofol (P < 0.001). ESVR in the thiopentone group decreased, but this was not statistically significant. ESVR increased significantly by 12% 1 min after induction of anaesthesia with etomidate (P < 0.05) and then decreased towards pre-induction values. The results suggest that the cardiostability of etomidate may not be as complete in all groups of patients as previous studies have suggested.
authors.affiliation: Department of Anaesthetics, St Georges Hospital, London.
authors.forename: M L
authors.initials: ML
authors.lastname: Price
authors.forename: B
authors.initials: B
authors.lastname: Millar
authors.forename: M
authors.initials: M
authors.lastname: Grounds
authors.forename: J
authors.initials: J
authors.lastname: Cashman
mesh_terms: D001783:Blood Flow Velocity / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects*; D005045:Etomidate / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008723:Methohexital / Q000494:pharmacology*; D015742:Propofol / Q000494:pharmacology*; D011897:Random Allocation; D013318:Stroke Volume / Q000187:drug effects; D013874:Thiopental / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D008723:Methohexital; D013874:Thiopental; D015742:Propofol; D005045:Etomidate