Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys

Steven C. Koenig, David Ludwig, Craig Reister, John W. Fanton, Dan Ewert, Victor A. Convertino

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Effects of prescribed doses of ketamine five minutes after application and influences of transesophageal echocardiography (TEE) on left ventricular, systemic arterial, and baroreflex responses were investigated to test the hypothesis that ketamine and/or TEE probe insertion alter cardiovascular function. Seven rhesus monkeys were tested under each of four randomly selected experimental conditions: (1) intravenous bolus dose of ketamine (0.5 ml), (2) continuous infusion of ketamine (500 mg/kg(min), (3) continuous infusion of ketamine (500 mg/kg(min) with TEE, and (4) control (no ketamine or TEE). Monkeys were chronically instrumented with a high fidelity, dual-sensor micromanometer to measure left ventricular and aortic pressure and a transit-time ultrasound probe to measure aortic flow. These measures were used to calculate left ventricular function. A 4-element Windkessel lumped-parameter model was used to estimate total peripheral resistance and systemic arterial compliance. Baroreflex response was calculated as the change in R-R interval divided by the change in mean aortic pressure measured during administration of graded concentrations of nitroprusside. The results indicated that five minutes after ketamine application heart rate and left ventricular diastolic compliance decreased while TEE increased aortic systolic and diastolic pressure. We conclude that ketamine may be administered as either a bolus or continuous infusion without affecting cardiovascular function 5 minutes after application while the insertion of a TEE probe will increase aortic pressure. The results for both ketamine and TEE illustrate the classic "Hawthorne Effect," where the observed values are partly a function of the measurement process. Measures of aortic pressure, heart rate, and left ventricular diastolic pressure should be viewed as relative, as opposed to absolute, when organisms are sedated with ketamine or instrumented with a TEE probe.

Original languageEnglish
Pages (from-to)513-517
Number of pages5
JournalComparative Medicine
Volume51
Issue number6
StatePublished - Dec 1 2001
Externally publishedYes

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Echocardiography
Baroreflex
Transesophageal Echocardiography
echocardiography
Ketamine
ketamine
Haplorhini
monkeys
Arterial Pressure
Ventricular Pressure
Blood Pressure
compliance
Compliance
heart rate
Heart Rate
Epidemiologic Effect Modifiers
Nitroprusside
dosage
Macaca mulatta
Left Ventricular Function

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Koenig, S. C., Ludwig, D., Reister, C., Fanton, J. W., Ewert, D., & Convertino, V. A. (2001). Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys. Comparative Medicine, 51(6), 513-517.

Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys. / Koenig, Steven C.; Ludwig, David; Reister, Craig; Fanton, John W.; Ewert, Dan; Convertino, Victor A.

In: Comparative Medicine, Vol. 51, No. 6, 01.12.2001, p. 513-517.

Research output: Contribution to journalArticle

Koenig, SC, Ludwig, D, Reister, C, Fanton, JW, Ewert, D & Convertino, VA 2001, 'Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys', Comparative Medicine, vol. 51, no. 6, pp. 513-517.
Koenig SC, Ludwig D, Reister C, Fanton JW, Ewert D, Convertino VA. Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys. Comparative Medicine. 2001 Dec 1;51(6):513-517.
Koenig, Steven C. ; Ludwig, David ; Reister, Craig ; Fanton, John W. ; Ewert, Dan ; Convertino, Victor A. / Left ventricular, systemic arterial, and baroreflex responses to ketamine and TEE in chronically instrumented monkeys. In: Comparative Medicine. 2001 ; Vol. 51, No. 6. pp. 513-517.
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