European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery
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Eur J Cardiothorac Surg · Jan 1996
Randomized Controlled Trial Clinical TrialThoracolumbar epidural blockade as adjunct to high dose fentanyl/midazolam anesthesia in coronary surgery: effects of sternotomy.
The present study tests the hypothesis that the changes in myocardial lactate metabolism in the early period of coronary surgery are caused by raised adrenergic activity, and that these are preventable by the addition of thoracolumbar epidural blockade to high dose fentanyl/midazolam anesthesia. Twenty-seven male beta 1-blocked patients undergoing coronary surgery were included in a prospective, controlled, randomized study. High dose fentanyl/midazolam anesthesia alone (control) or supplemented with thoracolumbar epidural blockade (treatment) was used. ⋯ The myocardial fractional extraction of lactate decreased in both groups, from 33 (10-45) to 13 (0-42)% in the control group (P < 0.01), and from 36 (19-43) to 10 (2-20)% in the epidural group. It is concluded that high dose fentanyl/midazolam anesthesia prevents hyperadrenergic activity in the early phase of coronary surgery, but cannot eliminate changes in myocardial lactate metabolism. The addition of the thoracolumbar epidural blockade to high dose fentanyl/midazolam anesthesia offers no obvious benefits in the early phase of coronary surgery.
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Eur J Cardiothorac Surg · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialIntraoperative internal mammary artery transit-time flow measurements: comparative evaluation of two surgical pedicle preparation techniques.
Myocardial revascularization is performed preferentially with internal mammary artery grafts. Pedicle preparation and pharmacologic vasodilatory treatment vary greatly. Objective measurements are difficult since peripheral and later coronary vascular resistance and possible competitive flow of the native bypassed coronary artery will influence the results significantly. Our objectives were: (1) measurement of internal mammary artery graft flow with the transit-time flow technique; (2) comparison of two surgical take-down techniques (skeletonizing vs standard pedicle preparation); (3) quantitation of transit-time flow compared to the free pedicle flow and (4) the vasodilatory effect of papaverine on internal mammary artery flow. ⋯ Intraoperative transit-time flow measurement is a reliable method for assessing internal mammary artery and coronary artery bypass flow; considering the simple technical application, the procedure may be regarded as a valuable instrument of quality control.
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Eur J Cardiothorac Surg · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialComplete heparin-coated (CBAS) cardiopulmonary bypass and reduced systemic heparin dose; effects on coagulation and fibrinolysis.
Heparin-coated extracorporeal circuits allow reduced amounts of systemic heparin and protamine. However, the effects on the coagulation and fibrinolytic systems when reducing systemic anticoagulation, have partly remained unknown. ⋯ Completely heparin-coated CPB can safely be performed in combination with reduced systemic heparinization. The heparin and protamine amounts could be lowered to 35% of normal doses. Indications of more thrombin generation on CPB compared to the uncoated controls were seen, but the levels remained within low ranges in both groups. There was no evidence of thromboembolic episodes or clot formation in the extracorporeal circuits.
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This review discusses the phenomenon of ischaemic preconditioning and its potential application to cardiac surgery. The biology of ischaemic preconditioning is explained and the more limited evidence suggesting that the human heart can be preconditioned is discussed. ⋯ Preconditioning is a powerful and reproducible method of protecting the myocardium from irreversible ischaemic injury. There is now evidence indicating that the human heart can be preconditioned. However, more trials are necessary in patients undergoing cardiac surgery before the role of preconditioning as a means of myocardial protection can be assessed.
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Eur J Cardiothorac Surg · Jan 1996
Case ReportsMultilevel somatosensory evoked potentials (SEPs) for spinal cord monitoring in descending thoracic and thoraco-abdominal aortic surgery.
The usefulness of somatosensory evoked potential (SEP) monitoring as a means of preventing paraplegia in descending aorta surgery was evaluated in 47 consecutive cases operated on for isthmic (14 cases), thoracic (22 cases), or thoraco-abdominal (11 cases) repair. An aortic dissection was found in 11 cases (acute in 6). Somatosensory evoked potentials were obtained by unilateral left and right posterior tibial nerve (PTN) stimulation at the ankle and recordings were performed on four channels: peripheral nerve, lumbar spinal, brain-stem, and cortical recordings. ⋯ Somatosensory evoked potential specificity was also 100%, but only 58% of the abnormalities found were actually consequent to spinal cord ischemia, the rest of the abnormalities being consequent to peripheral nerve or brain ischemia. Finally, SEP monitoring had a significant impact on surgical strategy in 19% of the cases. It is concluded that distal aortic perfusion and multilevel SEP monitoring play a significant role in preventing paraplegia in descending aorta surgery.