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Cardiodynamic Effects of Propofol in Comparison With Thiopental: Assessment With a Transesophageal Echocardiographic Approach

Mulier, Jan P. MD; Wouters, Patrick F. MD; Aken, Hugo Van MD, PhD; Vermaut, Gery MD; Vandermeersch, Eugène MD
Anesthesia & Analgesia: January 1991
SCIENTIFIC ARTICLE: PDF Only

In 40 patients, the cardiovascular effects of low- and high-dose propofol anesthesia (single bolus of 2.5 mg/kg in group A, 2.5 mg/kg in group C) were examined and compared with those of low- and high-dose thiopental (4 mg/kg in group B, 6.5 mg/kg in group D) (n = 10 patients per group). After induction of anesthesia with etomidate, all patients were ventilated with 70% nitrous oxide in oxygen. Peripheral arterial systolic blood pressure (SAP) and transesophageal echocardiographic short-axis measurements were used to calculate the end-systolic pressure-volume relationship (E) as an index of global myocardial contractility. In all groups SAP decreased significantly below baseline levels for the duration of the measurements (15 min after drug administration), except for the lower dose of thiopental, where SAP returned to baseline values within 10 min. Propofol at a dose of 1.5 mg/kg significantly decreased cardiac output (CO) (from 5.1 t 0.25 [mean ± SEM] to 4.2 ± 0.23 L/min), stroke volume (SV) (from 64 ± 3 to 56 ± 3.6 mL), and the slope of E (from 71 ± 3.5 to 65 ± 4.2 mm Hg/mL) until 4 min after drug administration.

The higher dose of propofol significantly decreased CO (from 5.1 ± 0.29 to 4.1 ± 0.26 L/min), SV (from 64 ± 3 to 52 ± 4.6 mL), and the slope of E (from 71 ± 3.6 to 62 ± 3.7 mm Hg/mL) until 20 min after drug administration. End-systolic volume increased significantly (from 60 ± 7.6 to 68 ± 5.5 mL) until the sixth minute, followed by a decrease in end-diastolic volume at 10 min (from 124 ± 6.5 to 118 ± 4.3 mL).

Thiopental at a dose of 4 mg/kg reduced end-diastolic volume significantly at 10 min (118 ± 7.2 versus 128 ± 7.8 mL) and resulted in a significantly higher CO (4.6 ± 0.29 versus 4.2 ± 0.23 L/min) and the slope of E (69 ± 3.9 versus 65 ± 4.2 mm Hg/mL) when compared with low-dose propofol at 4 min. Thiopental at a dose of 6.5 mg/kg significantly reduced the index of afterload (SAP/SV) (from 63 ± 5 to 56 ± 4.6 mm Hg/mL) and the slope of E (from 69 ± 4.2 to 63 ± 3.6 mm Hg/mL), whereas heart rate increased (from 76 ± 5.2 to 84 ± 6.8 beats/min) until the fourth minute after drug administration. When compared with high-dose propofol, end-systolic volume was significantly lower and SAP, SV, CO, and slope of E were significantly higher during thiopental at equipotent doses.

It is concluded that propofol reduces SAP mainly through its negative inotropic properties. Furthermore, the cardio-depressant effects of propofol are more pronounced and more prolonged than those of equipotent doses of thiopental when given as a single bolus.

Address correspondence to Dr. Mulier, Department of Anesthesiology, University Hospitals, Katholieke Universiteit Leuven, Herestraat 49, B-3000 Leuven, Belgium.

© 1991 International Anesthesia Research Society