Critical role of the extracorporeal blood temperature in the hemodynamic response during hemofiltration.
Impaired vascular reactivity during combined ultrafiltration-hemodialysis (UF+HD) compared with hemofiltration (HF) remains a rather enigmatic problem, the causes of which are still not well understood. Although a number of factors have been claimed to be responsible, most recent studies point to a major role of the extracorporeal blood temperature, which is usually lower during HF compared with UF + HD. However, previous studies in which hemodynamics were studied during UF + HD and HF in relation to the extracorporeal blood temperature are limited by the use of acetate in UF + HD, and measurements were often confined to BP and heart rate. Therefore, arterial BP, as well as forearm vascular resistance (FVR) and venous tone (strain-gauge plethysmography), was measured in 11 hemodialysis patients during 3 h UF + HD (37.5 degrees C) and predilution HF (39.0 degrees C = warm HF), resulting in equivalent extracorporeal blood temperatures. Patients were also studied during cold HF at an infusate temperature of 36.0 degrees C. UF + HD and HF were matched with respect to the dialysate and infusate composition (bicarbonate), bio-compatibility factors, and small molecule clearance. At equivalent temperatures, UF + HD and HF were associated with a comparable vascular and BP response. Only cold HF was associated with a significant increase in FVR. In addition, FVR and venous tone, as well as arterial BP, were all significantly higher during cold HF compared with both UF + HD and warm HF. These results indicate that the disparity in vascular reactivity between UF + HD and HF is primarily related to differences in the extracorporeal blood temperature.
van Kuijk
W H
WH
Department of Internal Medicine, University Hospital Maastricht, The Netherlands.
Hillion
D
D
Savoiu
C
C
Leunissen
K M
KM
D000328:Adult; D001790:Blood Physiological Phenomena; D001794:Blood Pressure; D005112:Extracorporeal Circulation; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate; D006439:Hemodynamics; D006440:Hemofiltration; D006801:Humans; D008875:Middle Aged; D006435:Renal Dialysis; D013696:Temperature; D014462:Ultrafiltration; D014655:Vascular Resistance; D014666:Vasomotor System / Q000502:physiology; D014680:Veins / Q000502:physiology