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An experimental study about post-ischemic perfusion of muscles with a new stroma-free hemoglobin solution is presented. Compared to other storage and perfusion methods the solution has several advantages: 1. Oxygenation and metabolism of the skeletal muscles are preserved. 2. Excellent wash-out effect. 3. The rheologic characteristics are better than those of whole blood. 4. No incompatibility. 5. No thrombogenetic effect. 6. The method is easy to manage. Our ultrastructural investigations show less damage of the muscle cells after a post-ischemic perfusion with oxygenated hemoglobin solution than after a post-ischemic physiological perfusion with whole blood.

In order to evaluate the possible differences in response to two currently preferable inotropic-vasodilator drug combinations, the hemodynamic effects of automated infusions of nitroprusside-dobutamine and nitroprusside-dopamine were studied in two clinically similar groups of patients with low-output syndrome after aorto-coronary bypass surgery. Nitroprusside, when infused in combination with dopamine, was effective in lowering filling pressures of both ventricles and systemic and pulmonary arterial pressures reflecting the reversal of deleterious rise of these parameters including determinants of myocardial oxygen consumption (mean arterial pressure rate by +6%, heart rate by +20%) caused by dopamine (6 micrograms/kg/min) infused alone. The combination of the more cardioselective catecholamine dobutamine with nitroprusside brought about similar increase in cardiac output by 50%, but derived its hemodynamic efficiency from the sum of separate effects of components and produced less in the way of elevation of determinants of oxygen consumption. Dobutamine when infused alone (6 micrograms/kg/min) has not affected systemic and pulmonary arterial pressures and stroke index rose more markedly (+9%) as a result of more moderate heart rate increase (+13%). Nitroprusside contributed in an additive manner to the achieved overall reduction of SVR and PVR by 43% and 50%, resp., the automated infusion being helpful in maintaining these values within close tolerances.

The mortality rate of chest injuries sustained during work or in road accidents stands now at 15-20%. The considerable force of the impact in road accidents is, in 60-80% of the cases, responsible for chest injuries which involve not only the chest wall but also the lungs. The extent and course of the lung damage must be assessed by repeated X-ray examinations, blood gas analyses and clinical observations. The decision to intubate and apply artificial ventilation should be made at an early stage. Fracture of a single rib needs only pain killers. If a rib is broken in several places or if several ribs are fractured instability of the chest wall is apt to develop in 15-20% of the cases. It manifests itself in paradoxical breathing and ensuing increase in the dead space. These cases require prompt "internal pneumatic splinting" in the form of positive pressure respiration and intubation. In recent years surgical stabilization of the chest wall has regained favour. Plate osteosynthesis, screw-less rib plates, self-gripping steel plates and steel splints are being used (Brunner, Hofmeister, Koncz). Primary osteosynthetic stabilization of the chest wall is indicated only if artificial ventilation has proved inadequate and there are other reasons for performing a thoracotomy. In these circumstances surgical intervention ensures that prolonged artificial ventilation and its attendent risks and complications and the demands made on the nursing staff are reduced to a minimum.

In the study of hemodynamics of hypertensive patients with low-output syndrome after open-heart surgery (the closed loop control of mean arterial pressure with nitroprusside, n = 14), evidence was obtained that the baseline SVR is a valuable index for predicting the response to vasodilation. Patients with markedly elevated SVR (n = 11) (1800 dyn. s. cm-5) responded favorably to vasodilation with SVR fall (from 2300 +/- 500 dyn X cm-5 to 1400 +/- 300 dyn X cm-5, p less than 0.005, -37%), cardiac index rise (from 2.1 +/- 0.3 to 2.4 +/- 0.4 l/min. m2, p less than 0.05 + 14%), or stroke volume index elevation (from 23.4 to 26.7 ml/m2, p less than 0.05, +14%). In patients with slightly raised SVR close to the normal range a mild SVR reduction (by 10%) occurred but no cardiac index increase with vasodilation alone. These patients derived their hemodynamic benefit from a combination of NP with preload augmentation and possibly direct inotropic stimulation. By assessing SVR before and during treatment with nitroprusside we were able to monitor more closely the course of automated afterload reduction and provide an additional important parameter for this regulation.

We present a case of intraoperative dissection of the aortic root in a patient with non-calcified aortic valve incompetence. This complication led to life-threatening bleeding from the dissection line into the layers of the left ventricle as well as the aortic wall with formation of an increasing subadventitial hematoma. The only possible management was to remove the valve prosthesis and to close the entry site of the dissection when reinserting the valve implant. The mechanism of this complication is discussed.

During open heart surgery, needle biopsy material was obtained in four patients, and electron microscopic preparations of the mitochondrial ATPases (coupling factors 1) in human myocardial cells were performed. The pre-ischemic, normal structure of the mitochondrial ATPases and the changes which occur during the ischemic interval were described. An increase in the center-to-center space was shown in the post-ischemic phase. This result was discussed for the pathogenesis of subcellular injuries due to ischemia.