The effects of induction of anaesthesia by ketamine 2 mg.kg-1 were studied in six patients with valvular heart disease before tracheal intubation and operation. Cardiac index was unaffected because a mean decrease in stroke index was compensated for a mean increase in heart rate. A significant increase was found in mean arterial pressure, pulmonary arterial mean pressure, pulmonary capillary wedge pressure and central venous pressure. Systemic vascular resistance increased, but not significantly, whereas pulmonary vascular resistance increased significantly by more than 150 per cent. Right ventricular minute work index increased in all patients, and the increase was as much as 400 per cent. Left ventricular minute work index increased in four of the six patients, but the magnitude of the increase was not so marked. It is therefore concluded that ketamine causes pronounced pulmonary vasoconstriction and an undesirable strain on the myocardium. Such effects could prove deleterious in patients with limited functional reserve of the right ventricle.
Two techniques for catheterization of the internal jugular vein are described in detail. In a group of 108 adults and 54 children, catheterization of the internal jugular vein was attempted 168 times. Failure to achieve catheterization occurred 12 times. The success rate for the first 50 patients was 86%, but it increased with experience, and was nearly 96% for the remaining patients. Almost 90% of catheterizations were achieved on the first or second attempt. The success rate was understandably lower in the children's group. Catheter malpositioning occurred infrequently (six times) and was most common in the children's group. There were few complications, although two were of a serious nature. The techniques described are straightforward, easy to master and perform, and are recommended as useful additions to the anaesthetist's clinical armamentarium.Address :
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