Effect of dialysate calcium concentrations on intradialytic blood pressure course in cardiac-compromised patients.
To prevent hypercalcemia in the treatment of secondary hyperparathyroidism, low calcium (L-Ca) dialysate is advocated. However, changes in ionized calcium (i-Ca) levels have a pivotal role in myocardial contraction and could influence blood pressure stability during dialysis. Recently, our group found in patients with normal cardiac function a significant decrease in blood pressure (decrease in systolic blood pressure [DSBP]: -13 mm Hg and decrease in mean arterial pressure [DMAP]: -7 mm Hg) during dialysis with L-Ca dialysate compared with high calcium (H-Ca) dialysate, and this was mainly related to a decreased left ventricular contractility with use of L-Ca dialysate. On the basis of these data, it could be expected that changes in i-Ca levels during dialysis are of more clinical importance in cardiac-compromised patients (CCpts), New York Heart Association classifications III and IV. In this study, the effects of L-Ca dialysate (1.25 mmol/L) and H-Ca dialysate (1.75 mmol/L) on arterial blood pressure parameters (systolic [SBP], diastolic [DBP], and mean arterial blood pressure [MAP]), heart rate, stroke distance (SDist), and minute distance (MDist) during 3 hours of a standardized ultrafiltration/hemodialysis (UF+HD) in nine CCpts was investigated. i-Ca levels increased significantly with H-Ca dialysate UF+HD, whereas there was no change with L-Ca dialysate. SBP, DBP, and MAP decreased statistically and clinically significantly during UF+HD with L-Ca dialysate and were significantly lower with the use of L-Ca dialysate compared with H-Ca dialysate. SDist and MDist decreased significantly with L-Ca dialysate, whereas there were no changes in SDist and MDist with H-Ca dialysate. The predialysis and postdialysis index of systemic vascular resistance (SVRI) was similar between L-Ca dialysate and H-Ca dialysate use. Between the two groups, there were no significant differences in changes in SVRI. From this study, we can conclude that changes in i-Ca levels are a very important determinant of the blood pressure response during UF+HD in CCpts, and this response is mediated by changes in myocardial contractility.
Department of Internal Medicine, academisch ziekenhuis Maastricht, The Netherlands. fvs@sint.azm.nl
F M
FM
van der Sande
E C
EC
Cheriex
W H
WH
van Kuijk
K M
KM
Leunissen
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology*; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology; D017583:Hemodiafiltration; D015312:Hemodialysis Solutions / Q000737:chemistry* / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D006435:Renal Dialysis
D015312:Hemodialysis Solutions; D002118:Calcium