Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1980
Effects of the level of CPAP on central haemodynamics and oxygen transport.
The effects of different levels of continuous positive airway pressure (CPAP) on central haemodynamics and oxygen transport were studied in ten spontaneously breathing male patients who had undergone aortocoronary bypass graft operation 18 h earlier. With increasing CPAP levels ranging from 5 cmH2O(0.49kPa)(CPAP 5) to 15 cmH2O(1.47kPa)(CPAP 15), the cardiac index was found to decrease significantly, while the intraluminal pulmonary capillary wedge and right atrial pressures increased simultaneously. The mean systemic arterial pressure remained unaltered, while the mean pulmonary arterial pressure increased with increasing CPAP. ⋯ Thus, low level CPAP might be beneficial in maintaining proper lung volume in an intubated patient after aortocoronary bypass surgery. The observations also suggest that, in these patients, CPAP levels exceeding 10 cmH2O bring about cardiac depression leading to an undesirable reduction in systemic oxygen transport. Mixed venous blood oxygen tension may offer information useful in the adjustment of the level of CPAP.
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Acta Anaesthesiol Scand · Aug 1980
Comparative StudyEffect of epidural versus general anaesthesia on calf blood flow.
The arterial inflow into the calf, venous emptying rate and venous capacity were studied by means of venous occlusion plethysmography on the non-operated leg in two groups of patients undergoing total hip replacement. One group of eight patients received epidural blockade intraoperatively, which was prolonged postoperatively for pain relief, while the other group of eight patients was given general anaesthesia with intermittent positive-pressure ventilation intraoperatively and parenteral analgesics for pain relief in the postoperative period. ⋯ The sustained reduction of flow in the deep veins of the lower limb might be a significant contributory factor in the initiation of deep venous thrombosis. In three of the eight patients in the general anaesthesia group, the venous emptying rate and venous capacity had decreased 3 h postoperatively to a very low level, indicating thrombus formation in immediate association with the surgery.
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Acta Anaesthesiol Scand · Jun 1980
Comparative StudyTemperature variations in disposable heat and moisture exchangers.
Temperature variations in different parts of three heat and moisture exchangers (HME) were measured during spontaneous breathing. Temperatures below ambient occurred in the distal part of two of them. The lowest temperatures recorded were more than 6 degrees C below room temperature. This effect can explain why gas expired through a good HME is not saturated with water at ambient temperature.
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Acta Anaesthesiol Scand · Jun 1980
Case ReportsEar injury caused by elevated intratympanic pressure during general anaesthesia.
Two cases of middle-ear injury, due to sharp fluctuations of intratympanic pressure as a result of general anaesthesia with nitrous oxide are presented. A study is reported indicating that the degree of these fluctuations is a function of the concentration of nitrous oxide. In order to reduce the risk of middle-ear injury due to nitrous oxide anaesthesia, it is suggested that the lowest concentration feasible should be used where there is a history of previous ear surgery.
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Acta Anaesthesiol Scand · Jun 1980
Anesthesia for cesarean section--VII. Early effects on neonatal renal function of enflurane anesthesia for cesarean section.
Fourteen women undergoing elective cesarean section were anesthetized with enflurane for induction and maintenance of anesthesia. Blood enflurane and serum inorganic fluoride levels were studied in the mothers at delivery and in the neonates at delivery and in the early neonatal period. Also neonatal urinary excretion of inorganic fluoride was determined. ⋯ The level of inorganic fluoride in urine was higher than the corresponding serum level, indicating an inorganic fluoride concentrating effect of the neonatal kidney. The difference between urinary excretion and serum content of inorganic fluoride showed neonatal metabolism of enflurane. The urinary sodium excretion did not differ from that of infants delivered without halogenated inhalation agents given to the mothers.