[Alterations of cardiac output during bicarbonate hemodialysis and its relationship with other hemodynamic parameters].
OBJECTIVE
Time course of cardiac output (CO) and other hemodynamic parameters were measured during hemodialysis (HD). Our aims were to identify a characteristic CO profile and investigate the relationship with other hemodynamic parameters.


METHODS
CO was measured with ultrasound dilution method in 45 chronic hemodynamically stable HD patients. Diabetics and patients with heart diseases were excluded. Ultrafiltration rate (UFR) was fixed at 649 +/- 244 mL/min. Pre/post statistical comparisons were performed for CO, cardiac index (IC), central blood volume (CBV) and total peripheral resistance (TPR).


RESULTS
CO was pre 5.7 +/- 1.8 and post 4.5 +/- 1.4 L/min (p=0.001); IC was pre 3.2 +/- 0.9 and post 2.6 +/- 0.7 L/m2 (p=0.001); CBV was pre 1.28 +/- 0.39 and post 1.09 +/- 0.32 L (p=0.001). TPR increased from 18.7 +/- 5.6 to 22.7 +/- 6.1 mmHg/L/min (p=0.001). Maximal CO reduction rate was found at 60 min, thereafter it reduced progressively. Log(CO1) increased in a non-linear way with body weight gain and similarly it decreased during UFR. A negative correlation was found between log(TPR1) and log(CO1-QA). CO reduction was associated with UFR and not with age, dialysis duration, left ventricular hypertrophy, sex and hemoglobin (Hb) in a multiple regression model (r2 =0.31, p=0.05). Qa/CO1 was 0.16 +/- 0.12. CBV/CO increased from 0.23 +/- 0.06 to 0.25 +/- 0.07%.


CONCLUSIONS
Progressive CO reduction and TPR increase appear to be the typical hemodynamic features of bicarbonate HD with a UFR of moderate degree. Volume overload and CO increase were related in a non-linear way. TPR1 was strongly correlated with CO1-Qa, suggesting that a large arterovenous shunt was associated with increased resistance.
Rivera
R
R
U.O. di Clinica Nefrologica, Ospedale di Monza. rfrmdphd@hotmail.com
Arrigo
G
G
Mandolfo
S
S
Bonforte
G
G
Giordano
A
A
Colasanti
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001639:Bicarbonates / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis
D001639:Bicarbonates