5 research outputs found
Blood volume regulation during hemodialysis
The blood pressure response during dialysis depends on blood volume preservation and/on changes in vascular tone. However, these two are not independent. In order to delineate the role of blood volume profiling in the prevention of intradialytic hypotension, more information is needed on the relationship between these physiological defense mechanisms.
Therefore, we performed several studies to clarify this relationship and to improve the understanding of dialysis related hypotension. Such understanding is desperately needed before preventive measures can be initiated
Preload dependence of new Doppler techniques limits their utility for left ventricular diastolic function assessment in hemodialysis patients
Left ventricular (LV) hypertrophy leads to diastolic dysfunction. Standard
Doppler transmitral and pulmonary vein (PV) flow velocity measurements are
preload dependent. New techniques such as mitral annulus velocity by
Doppler tissue imaging (DTI) and LV inflow propagation velocity measured
from color M-mode have been proposed as relatively preload-independent
measurements of diastolic function. These parameters were studied before
and after hemodialysis (HD) with ultrafiltration to test their potential
advantage for LV diastolic function assessment in HD patients. Ten
patients (seven with LV hypertrophy) underwent Doppler echocardiography 1
h before, 1 h after, and 1 d after HD. Early (E) and atrial (A) peak
transmitral flow velocities, peak PV systolic (s) and diastolic (d) flow
velocities, peak e and a mitral annulus velocities in DTI, and early
diastolic LV flow propagation velocity (V(p)) were measured. In all
patients, the E/A ratio after HD (0.54; 0.37 to 1.02) was lower (P < 0.01)
than before HD (0.77; 0.60 to 1.34). E decreased (P < 0.01), whereas A did
not. PV s/d after HD (2.15; 1.08 to 3.90) was higher (P < 0.01) than
before HD (1.80; 1.25 to 2.68). Tissue e/a after HD (0.40; 0.26 to 0.96)
was lower (P < 0.01) than before HD (0.56; 0.40 to 1.05). Tissue e
decreased (P < 0.02), whereas a did not. V(p) after HD (30 cm/s; 16 to 47
cm/s) was lower (P < 0.01) than before HD (45 cm/s; 32 to 60 cm/s).
Twenty-four hours after the initial measurements values for E/A (0.59;
0.37 to 1.23), PV s/d (1.85; 1.07 to 3.38), e/a (0.41; 0.27 to 1.06), and
V(p) (28 cm/s; 23 to 33 cm/s) were similar as those taken 1 h after HD. It
is concluded that, even when using the newer Doppler techniques DTI and
color M-mode, pseudonormalization, which was due to volume overload before
HD, resulted in underestimation of the degree of diastolic dysfunction.
Therefore, the advantage of these techniques over conventional parameters
for the assessment of LV diastolic function in HD patients is limited.
Assessment of LV diastolic function should not be performed shortly before
HD, and its time relation to HD is essential
Development of the Rotterdam Renal Replacement Knowledge-Test (R3K-T)
Introduction: There is currently a lack of validated or standardized measures to test the level of knowledge among renal patients regarding kidney disease and available treatment options. We conducted a pilot study to develop a questionnaire measuring knowledge of kidney disease, dialysis and transplantation options. The main aim of this study was to develop such an instrument for further use in research and practice.
Method: An initial 61 item pool was generating by searching the literature and consulting experts in this area for additional items. This questionnaire was completed by 182 renal disease patients from 4 dialysis centers in the Rotterdam municipality. A factor analysis was conducted using the maximum likelihood factor method followed by direct oblimin rotation to obtain variance explained by each factor. Questions that loaded ≥ .30 on a factor were included.
Results: Twenty-seven patients (24%) were in the pre-RRT phase, 60 (54%) were undergoing haemodialysis, 16 (14%) were undergoing peritoneal dialysis, and 9 (8%) had a graft failure. Forty (36%) were female and 72 (64%) were male. Age range 19-87 (median = 59). A factor analys
Variability of relative blood volume during haemodialysis
BACKGROUND: A decrease in blood volume is thought to play a role in
dialysis-related hypotension. Changes in relative blood volume (RBV) can
be assessed by means of continuous haematocrit measurement. We studied the
variability of RBV changes, and the relation between RBV and
ultrafiltration volume (UV), blood pressure, heart rate, and inferior
caval vein (ICV) diameter. METHODS: In 10 patients on chronic
haemodialysis, RBV measurement was performed during a total of one hundred
4-h haemodialysis sessions. Blood pressure and heart rate were measured at
5-min intervals. ICV diameter was assessed at the start and at the end of
dialysis using ultrasonography. RESULTS: The changes in RBV showed
considerable inter-individual variability. The average change in RBV
ranged from -0.5 to -8.2% at 60 min and from -3.7 to -14.5% at 240 min
(coefficient of variation (CV) 0.66 and 0.35 respectively).
Intra-individual variability was also high (CV at 60 min 0.93; CV at 240
min 0.33). Inter-individual as well as intra-individual variability showed
only minor improvement when RBV was corrected for UV. We found a
significant correlation between RBV and UV at 60 (r= -0.69; P<0.001) and
at 240 min (r= -0.63; P<0.001). There was a significant correlation
between RBV and heart rate (r= -0.39; P<0.001), but not between RBV or UV
and blood pressure. The level of RBV reduction at which hypotension
occurred was also highly variable. ICV diameter decreased from 10.3+/-1.7
mm/m(2) to 7.3+/-1. 5 mm/m(2). There was only a slight, although
significant, correlation between ICV diameter and RBV (r= -0.23; P<0.05).
The change in ICV-diameter showed a wide variation. CONCLUSIONS: RBV
changes during haemodialysis showed a considerable intra- and
inter-individual variability that could not be explained by differences in
UV. No correlation was observed between UV or changes in RBV and either
blood pressure or the incidence of hypotension. Heart rate, however, was
significantly correlated with RBV. Moreover, IVC diameter was only poorly
correlated with RBV, suggesting a redistribution of blood towards the
central venous compartment. These data indicate that RBV monitoring is of
limited use in the prevention of dialysis-related hypotension, and that
the critical level of reduction in RBV at which hypotension occurs depends
on cardiovascular defence mechanisms such as sympathetic drive
Specific effect of the infusion of glucose on blood volume during haemodialysis
BACKGROUND: Intradialytic morbid events such as hypotension and cramps
during haemodialysis are generally treated by infusion of iso- or
hypertonic solutions. However, differences may exist between solutions
with respect to plasma refilling and vascular reactivity. METHODS: We
compared the effect of no infusion (NI) with isovolumetric infusion of
isotonic saline 0.9% (IS), saline 3% (HS), isotonic glucose 5% (IG),
glucose 20% (HG) and mannitol 20% (HM), in six patients during the first
hour of six standardized haemodialysis sessions with ultrafiltration.
Relative blood volume was monitored continuously by measurement of the
intravascular amount of protein. Blood pressure was measured by an
oscillometric method, while cardiac output was measured by a thoracic
impedance technique. RESULTS: At baseline, no differences in serum urea,
sodium, potassium, glucose and osmolarity were found between the various
infusion experiments. The maximum increase in relative blood volume
directly after infusion was significantly greater with HG (5.1+/-0.7%)
than with all other infusions (P<0.05). Stroke volume increased
(21.0+/-19.2%, P<0.05) and total peripheral resistance decreased
significantly (15.4+/-16.4%, P<0.05) after HG infusions. CONCLUSIONS:
Infusion of hypertonic glucose during dialysis results in a greater
increase in relative blood volume (RBV) than equal volumes of other
solutions. As mannitol has the same osmolarity, molecule mass and charge,
the greater increase in RBV following hypertonic glucose appears to be a
specific effect, possibly related to a decline in vascular tone. It is
therefore uncertain whether the observed increase in plasma volume during
hypertonic glucose infusions will be of clinical benefit