RESUMO
The internal mammary artery is clearly the preferred conduit for most patients undergoing coronary artery bypass grafting. However, the hemodynamic responses of this graft to vasoactive agents immediately after bypass have not been documented. We have therefore studied blood flow in the canine internal mammary artery after anastomosis to the left anterior descending artery, and its response to epinephrine, metaraminol, isoproterenol, and calcium chloride. Blood flow in the internal mammary artery clearly paralleled changes in systolic blood pressure with perfusion pressure being of prime importance in maintaining flow in the internal mammary artery. No deleterious effect of systemic vasoconstricting agents was demonstrated. We suggest that the administration of these drugs is safe in patients with internal mammary artery grafts.
Assuntos
Cloreto de Cálcio/farmacologia , Epinefrina/farmacologia , Anastomose de Artéria Torácica Interna-Coronária , Isoproterenol/farmacologia , Artéria Torácica Interna/efeitos dos fármacos , Metaraminol/farmacologia , Artérias Torácicas/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Cães , Frequência Cardíaca/efeitos dos fármacosRESUMO
The ability to reliably estimate pulmonary artery wedge pressure measurements using the clinical and basic cardiovascular parameters was assessed in fifty-six patients having elective coronary artery bypass surgery. The patients were divided into three groups: Group 1 had normal left ventricular function (22 patients), Group 2 had moderate left ventricular dysfunction (20 patients) and Group 3 had more severe left ventricular dysfunction (14 patients). The percentages of correct pulmonary artery wedge pressure estimations were 55%, 56% and 52% in Groups 1, 2 and 3 respectively. We conclude that pulmonary artery wedge pressure measurements can only be reliably estimated from the clinical situation and basic cardiovascular parameters on about 50% of occasions and that the reliability of the estimation does not vary between groups with different left ventricular performance.
Assuntos
Anestesia Geral , Ponte de Artéria Coronária , Doença das Coronárias/cirurgia , Pressão Propulsora Pulmonar , Pressão Sanguínea , Pressão Venosa Central , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A prospective randomised study of two hundred patients undergoing open-heart surgery was carried out to determine if the method of radial artery cannulation (direct threading or transfixion) had any influence on the incidence of abnormal flow after decannulation. A standard 20-gauge non-tapered teflon-coated cannula was used and the groups were well matched for age, sex, wrist circumference, duration of cannulation and haematoma formation, all of which have been postulated to influence thrombosis rate. We were unable to demonstrate a statistically significant difference between the two methods of cannulation. The overall abnormal flow rate at five days assessed by Doppler ultrasound was low at 5%.