Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jan 1987
Circulatory effects of short-term hypercapnia during high thoracic epidural anaesthesia in elderly patients.
Circulatory changes and the degree of sympathetic block were evaluated in 15 elderly patients with high thoracic epidural anaesthesia (T1-T5). Bupivacaine 5-6 ml 0.5% was injected via an epidural catheter at the T3-level. The quality of the sympathetic block was determined with the Valsalva manoeuvre. ⋯ During hypercapnia, heart rate and arterial blood pressure increased both before and after established TEA. Thus the block of the sympathetic innervation to the heart with a high TEA using 0.5% bupivacaine was not sufficient to prevent mobilization of circulatory reserves during sympathetic stimulation. The most likely explanation is considered to be the lack of neural block of the efferent nerves leading to the adrenal medulla and the peripheral vascular bed.
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Acta Anaesthesiol Scand · Jan 1987
Continuous measurement of oxygen uptake. Evaluation of the Engström metabolic computer and clinical experiences.
A new system for continuous measurement of oxygen uptake was tested. The tidal volumes delivered by the system, the accuracy of the oxygen sensor cell, measurement of the oxygen uptake at different inspired oxygen concentrations, and comparative tests of oxygen uptake using the Fick principle were studied. Judging from our results, even thorough maintenance could not entirely prevent leakages. ⋯ In comparative tests of oxygen uptake using the Fick principle (cardiac output and arteriovenous oxygen content difference), we found a mean difference between EMC and the Fick principle of about 6.6% (P less than or equal to 0.001, r = 0.91) with nearly identical standard deviations for both values. Our experience indicates that the EMC is suitable for continuous measurements of oxygen uptake. Additional technical improvements seem to be possible.