A qualitative analysis of pulsatile perfusion: effects on cortisol response to cardiopulmonary bypass surgery

Continuous analysis of pressure waveform has enabled quantitative assessment of pulsatile perfusion in a series of 51 patients randomly allocated to "pulsatile" (N = 37) and "non-pulsatile" (N = 14) groups. Cortisol and hematocrit (PCV) were measured preoperatively, at 2 minutes and 30 minutes after the start of bypass and just prior to the end of bypass. Radial artery pressure, pulse pressure and dp/dt were recorded continuously on a specially constructed device. Though there was significant difference between the pulsatile and non-pulsatile groups in terms of pulse pressure (P less than 0.001) and dp/dt (P less than 0.01), no difference was demonstrated in terms of mean arterial pressure (P greater than 0.4), total plasma cortisol (P greater than 0.9) and PCV corrected plasma cortisol (P greater than 0.8). Multiple regression analysis of cortisol and change in cortisol with pulse pressure dp/dt and mean arterial pressure failed to show any correlation. We found a normal cortisol response to surgery irrespective of the quality of pulsation.