Browsing by Author "Fourie, P. R."
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- ItemDrukomsetters in die kliniese en navorsingspraktyk : 'n kort kritiese beskouing(Health & Medical Publishing Group, 1987) Fourie, P. R.; Badenhorst, E.; Coetzee, A. R.The correct measurement of various blood pressures in clinical practice is of obvious importance. A method by which the frequency response and damping of various transducers and catheters can be determined is discussed and reference is made to values obtained in the validation of certain catheters.
- ItemThe effect of halothane, enflurane and isoflurane on the circulation(Health & Medical Publishing Group, 1989) Coetzee, A. R.; Fourie, P. R.; Badenhorst, E.This study, in open-chest dogs, sought to explore the relationship between whole-body oxygen delivery and oxygen consumption during anaesthesia, using increasing concentrations of halothane, enflurane and isoflurane. Results indicate that the cardiac index and oxygen delivery became critical at less than 1 MAC (minimal alveolar concentration of anaesthetic) for the three commonly used vapours. Halothane caused the least depression of contractility, but the stroke volume was reduced by the well-maintained afterload at 1 MAC. Enflurane and isoflurane were associated with more depression of contractility, but the cardiac output was maintained by an increase in heart rate in the case of isoflurane and reduced mean arterial pressure during the use of enflurane.
- ItemThe load independence of the end-systolic pressure-length relationship of the heart(Health & Medical Publishing Group, 1989) Coetzee, A. R.; Fourie, P. R.; Badenhorst, E.The end-systolic pressure-volume relationship is the state of the art in the measurement of myocardial contractility. This index is load-independent and relatively independent of heart rate. In this study the load-independent character of the end-systolic pressure-length (ESPL) relationship was evaluated in dogs under general anaesthesia. The result indicated that the ESPL is pre- and afterload-independent, since the comparative values of ESPL from afterloaded and reduced preload contractions did not differ significantly (N = 75; P = 0.5993). The application of the ESPL relationship as a means of describing the function of the heart as a muscle as well as a pump is discussed.
- ItemDie suurstofbalans in die normale hondmiokardium gedurende toenemende konsentrasies van inhalasienarkosemiddels(Health & Medical Publishing Group, 1988) Coetzee, A. R.; Fourie, P. R.; Badenhorst, E.; Els, D.Myocardial oxygen supply and demand in the normal dog were evaluated as the concentration of halothane, enflurane or isoflurane was increased. Although coronary blood flow decreased as the anaesthetic gas concentration increased, the O2 supply-to-demand ratio remained stable owing to a decrease in the myocardial O2 consumption.