Hämodynamische Effekte einer Kombination von Etomidat, Flunitrazepam oder Midazolam mit Fentanyl zur Anästhesie-Einleitung bei Patienten mit Herzklappenvitien

Ketamine-etomidate for children undergoing cardiac catheterization

The purpose of this study was to determine the effects of combined low-dose ketamine and etomidate on hemodynamics during cardiac catheterization in children with congenital cardiac shunts. Sixty children undergoing routine diagnostic cardiac catheterization were included: 30 had a right-to-left shunt, and 30 had a left-to-right shunt. Both groups were given a single dose of etomidate 0.3 mg·kg(-1) with ketamine 1 mg·kg(-1). There were no hemodynamic changes in the group with a right-to-left shunt. In cases of left-to-right shunt, there were significant differences in heart rate, right atrial pressure, mean arterial pressure, mean pulmonary artery pressure, pulmonary artery wedge pressure, and systemic vascular resistance index. Decreases in pulmonary blood flow and pulmonary-systemic shunt ratio were also observed. Further studies are required with dose titration of this anesthetic combination in pediatric patients with congenital heart disease involving a left-to-right shunt.

Hemodynamic responses to etomidate in pediatric patients with congenital cardiac shunt lesions

OBJECTIVE

The authors investigated the effects of intravenous etomidate on hemodynamics in children with congenital cardiac shunts.

DESIGN

Prospective observational study.

SETTING

Catheterization laboratory in tertiary referral cardiac center.

PARTICIPANTS

Thirty children with congenital cardiac shunt lesions.

INTERVENTIONS

Fifteen children having congenital right to left shunts (group A) and 15 children with left to right shunts (group B) were studied. Systemic mean arterial pressure (SMAP), mean pulmonary artery pressures (MPAP), right atrial pressures (RAP), and pulmonary artery wedge pressure (PAWP) were recorded. Systemic vascular resistance index (SVRI), pulmonary vascular resistance index (PVRI), and pulmonary-to-systemic blood flow ratio (Qp/Qs) were calculated on room air at baseline and following a single dose of 0.3 mg/kg of etomidate.

MEASUREMENTS AND MAIN RESULTS

Heart rate (HR), SMAP, RAP, systemic blood flow (Qs), Qp/Qs, and SVRI did not show any significant change; whereas systemic arterial saturation increased from 77.3% to 79.3%, which was statistically but not clinically significant in the authors' opinion following etomidate in group A. No significant differences in HR, SMAP, MPAP, PAWP, PVRI, SVRI, Qs, pulmonary blood flow (Qp), and Qp/Qs ratio were seen; whereas RAP, systemic, and pulmonary artery saturation decreased in group B after etomidate. Although statistically significant, the decreases were not clinically significant.

CONCLUSION

Etomidate at 0.3 mg/kg produces very minimal changes in hemodynamic parameters and shunt fraction in children with congenital shunt lesions.

Effect of propofol and etomidate on normoxic and chronically hypoxic pulmonary artery

Background

Chronic alveolar hypoxia results in sustained arterial constriction, and increase in pulmonary vascular resistance leading to pulmonary artery hypertension (PAHT). The aim of this study was to investigate the effect of propofol and etomidate on pulmonary artery (PA) reactivity in chronically hypoxic (CH) rats, a model of pulmonary arterial hypertension (PAHT), in normoxic animals, and human PA.

Methods

CH rats were maintained 14 days at 380 mmHg pressure in a hypobaric chamber. Human tissue was retrieved from histological lung pieces from patients undergoing resection for carcinoma. Cumulative concentrations of anaesthetics were tested on isolated vascular rings precontracted with phenylephrine (PHE) or 100 mM KCl. Statistical comparisons were done by ANOVA, followed, when needed, by Student t tests with Bonferroni correction as post-hoc tests.

Results

In normoxic rat PA, maximal relaxation (R_max) induced by etomidate and propofol was 101.3 ± 0.8% and 94.0 ± 2.3%, respectively, in KCl-precontracted rings, and 63.3 ± 9.7% and 46.1 ± 9.1%, respectively, in PHE-precontracted rings (n = 7). In KCl-precontracted human PA, R_max was 84.7 ± 8.6 % and 66.5 ± 11.8%, for etomidate and propofol, respectively, and 154.2 ± 22.4 % and 51.6 ± 15.1 %, respectively, in PHE-precontracted human PA (n = 7). In CH rat PA, the relaxant effect of both anaesthetics was increased in PHE-precontracted and, for etomidate only, in KCl-precontracted PA. In aorta, CH induced no change in the relaxant effect of anaesthetics.

Conclusion

Propofol and etomidate have relaxant properties in PA from human and normoxic rat. The relaxant effect is specifically accentuated in PA from CH rat, mainly via an effect on the pharmacomechanical coupling. Etomidate appears to be more efficient than propofol at identical concentration, but, taking into account clinical concentrations, etomidate is less potent than propofol, which effect was in the range of clinical doses. Although these findings provide experimental support for the preferential use of etomidate for haemodynamic stability in patients suffering from PAHT, the clinical relevance of the observations requires further investigation.

Effects of propofol on cardiovascular dynamics and coronary blood flow in geriatric patients. A comparison with etomidate

The cardiovascular and myocardial effects of propofol and etomidate were studied in 20 geriatric patients (age 65-84 years) who underwent major upper abdominal surgery. Ten patients received propofol 1.5 mg/kg for induction of anaesthesia followed by a continuous infusion of 0.1 mg/kg/minute for maintenance; 10 patients received etomidate 18 mg for induction followed by 2.4 mg/minute for maintenance. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded in the awake state one minute after induction and 1, 5 and 30 minutes after tracheal intubation; coronary blood flow (argon wash-in) and myocardial oxygen consumption were determined in the awake state and 5 and 30 minutes after intubation. Both anaesthetics decreased systolic, diastolic and mean arterial pressures, heart rate and cardiac index to the same extent. Myocardial blood flow and oxygen consumption were also reduced in both groups due to a reduction in cardiac work. Tracheal intubation produced a marked increase in arterial pressure in the etomidate group, while haemodynamic changes were absent in the propofol group, Myocardial lactate production was not observed in either group 5 or 30 minutes after tracheal intubation.