The Influence of Thoracic Epidural Analgesia Alone and in Combination with General Anesthesia on Cardiovascular Function and Myocardial Metabolism in Patients Receiving ??-Adrenergic Blockers

Abstract

Thoracic epidural analgesia combined with chronic beta-adrenergic blocker medication may cause cardiac depression. We investigated the cardiovascular and myocardial metabolic effects of a T1-T12 epidural block in 18 patients (age < 65 yr, ejection fraction > 0.5), receiving chronic beta-adrenergic blocker medication and scheduled for aortocoronary bypass surgery. After randomization into a light or deeper general anesthetic group, the cardiovascular and myocardial metabolic effects of a subsequent general anesthesia induction were investigated. Thoracic epidural analgesia induced a moderate decrease in mean arterial pressure, coronary perfusion pressure, free fatty acids, and myocardial consumption of free fatty acids. General anesthesia with thiopental (2-4 mg/kg) and a low fentanyl dose (5 micrograms/kg) increased heart rate, coronary perfusion pressure, and coronary vascular resistance, whereas mean pulmonary arterial pressure and pulmonary capillary wedge pressure decreased. After thiopental (2-4 mg/kg) and a high fentanyl dose (30 micrograms/kg), mean arterial pressure and left ventricular stroke work index decreased. We conclude that a T1-T12 epidural block in well sedated, beta-adrenergic blocked patients does not induce clinically significant cardiovascular effects. Induction of general anesthesia was well tolerated, but the light general anesthetic could not prevent an increase in heart rate and coronary vascular resistance, whereas the deeper anesthetic induced slight myocardial depression. No effect on the atrioventricular conduction, as measured by the PQ-time, was noted.

Experimental Models of Hemorrhagic Shock: A Review

“…However, anesthesia usually depresses respiration, reduces metabolic demand [106], influences the central nervous system [107] and moderates cardiovascular compensatory mechanisms [108]. Furthermore, certain anesthetics change the immune function (production of cytokines and activity of natural killer cells) [109] and may facilitate bacterial translocation [110].…”

Beta-bloqueadores em anestesiologia: aspectos farmacológicos e clínicos

“…51 ceptores a e b-adrenérgicos distintos, forneceu o impulso para o estudo, a síntese e a avaliação farmacológica dos b-bloqueadores. Esforços posteriores resultaram em compostos com relativa afinidade diferenciada pelos receptores b 1 e b 2, atividade simpaticomimética intrínseca presente ou não e efeito estabilizador de membrana presente ou não (Tabela I).…”

“…Deve-se considerar que no bloqueio subaracnóideo ou peridural os efeitos cardiovasculares do beta-bloqueador podem se somar aos do bloqueio simpático e do anestésico local, em casos de superdosagem desse agente. Entretanto o seu uso no per-operatório durante bloqueios regionais, como na peridural torácica isolada ou combinada com anestesia geral, é considerado seguro 7,51 . A anestesia regional em paciente beta-bloqueado exige atenção especial para as correções de hipovolemia e de hipotensão arterial por agentes vasoativos e a correção da bradicardia com a atropina.…”

“…444 Revista Brasileira de Anestesiologia Vol. 51 In coronary patients or those with myocardial changes, it is important to decrease any ventricular rhythm increased by atrial rhythm changes. When stimulated at very fast rhythm, the ventricular myocardium often develops ventricular rhythm changes, such as extrasystole and tachycardia.…”

Kardioprotektion durch thorakale Periduralanästhesie?

“…6. Ob eine multimodale Kardioprotektion mit thorakaler PDA und perioperativer Applikation von β-RezeptorenBlockern bei gleichem Wirkansatz der Sympathikolyse einen additiven Effekt auf die Rate unerwünschter Bradykardien und Hypotensionen hat, ist unsicher[37,74]. In weniger als der Hälfte der für die Analysen selektierten Studien fanden sich Angaben über eine β-Rezeptoren-Blockermedikation; hierbei war der Anteil der Patienten mit präoperativer β-RezeptorenBlockermedikation in der PDA-bzw.Unterschiedliche Formen der Allgemeinanästhesie in der PDA-und in der Kontrollgruppe können ggf.…”