Reproducibility of systemic hemodynamics in stable chronic hemodialysis: a pilot study.

OBJECTIVE: Hemodynamic measurements are important in the understanding of hemodialysis (HD) hypertension and intradialytic hypotension. The reproducibility of hemodynamic measurements in HD patients is not known and is the objective of this report. METHODS: We enrolled 13 male patients (mean age 63+/-13 years) on stable chronic HD. Blood pressure (BP) and hemodynamic variables were obtained with a pulse dynamic technology device. Measurements were taken before and after HD, in the supine and standing positions over a 2-week period. RESULTS: Ranges for the average intraindividual standard deviation for each hemodynamic variable before and after HD in both supine and standing positions were: 8.3-14.5 mmHg for oscillometric systolic BP; 4.1-10.7 mmHg for oscillometric diastolic BP; 10.7-14.5 mmHg for manual systolic BP; 5.4-8.8 mmHg for manual diastolic BP; 131.4-188.9 mmHg/s for left ventricular dP/dtmax; 0.17-0.27 L/min/m for cardiac index; 142.4-222.6 dynes/s/cm for systemic vascular resistance; 0.59-1.13%/mmHg for brachial artery distensibility; and 0.09-0.15 ml/mmHg for systemic vascular compliance. Repeated measures analysis of variance results showed no significant variability in measures. Intraclass correlation coefficient ranges were 0.58-0.72 for oscillometric systolic BP, 0.46-0.83 for oscillometric diastolic BP, 0.41-0.62 for manual systolic BP, 0.57-0.84 for manual diastolic BP, 0.10-0.78 for left ventricular dP/dtmax, 0.63-0.84 for cardiac index, 0.47-0.80 for systemic vascular resistance, 0.40-0.84 for brachial artery distensibility, and 0.62-0.88 for systemic vascular compliance. No correlation was observed between interdialytic weight gain and hemodynamic variability. CONCLUSION: In this pilot study, hemodynamic variables have acceptable reproducibility in chronic stable HD patients. Our results are relevant to the use of hemodynamic monitoring in HD practice and research.

Reliability of a noninvasive device to measure systemic hemodynamics in hemodialysis patients.

OBJECTIVE: To evaluate the reliability of a noninvasive hemodynamic monitor in hemodialysis patients. METHODS: We enrolled 15 male patients (mean age 63+/-12 years) on stable chronic hemodialysis. Blood pressure and hemodynamic readings were obtained with the Dynapulse 500 Guardian device (Pulsemetric Inc., San Diego, California, USA), which measures systemic hemodynamics on the basis of oscillometric waveforms obtained through a cuff placed over the brachial artery. Measurements were taken sequentially, in duplicate, before, during and after hemodialysis, in the supine, seated and standing positions on four separate midweek dialysis sessions over a 2-week period. RESULTS: The repeatability of the method was tested using 200 pairs of valid measurements. The average values (+/-SD) were 137+/-22 mmHg for systolic blood pressure, 80+/-13 mmHg for diastolic blood pressure, 76+/-15 bpm for heart rate, 1320+/-268 mmHg/s for dP/dtmax, 2.8+/-0.5 l/min/m for cardiac index, and 1455+/-359 dyn/s/cm for systemic vascular resistance. The mean differences (+/-SD of the difference) between readings were 0.1+/-10.4 mmHg for systolic blood pressure, 0.3+/-6.0 mmHg for diastolic blood pressure, -0.2+/-8.0 bpm for heart rate, 0.2+/-234 mmHg/s for dP/dtmax, 0.03+/-0.26 l/min/m for cardiac index and -10+/-177 for systemic vascular resistance, yielding limits of agreement (95%) of -20 to 20 mmHg for systolic blood pressure, -11 to 12 mmHg for diastolic blood pressure, -16 to 17 bpm for heart rate, -458 to 458 mmHg/s for dP/dtmax, -0.5 to 0.5 l/min/m for cardiac index and -338 to 357 dyn/s/cm for systemic vascular resistance. Other hemodynamic parameters fared similarly, and coefficients of variation were all between 7 and 18%. CONCLUSION: We conclude that the Dynapulse 500 Guardian has adequate reliability indices in hemodialysis patients.

Arterial compliance in elderly men with chronic kidney disease.

BACKGROUND/AIM: Chronic kidney disease (CKD) is associated with decreased arterial compliance (AC). The stage of development of impaired arterial function in CKD in relation to loss of glomerular filtration rate (GFR) is not known. This study's aim was to evaluate the relationship between GFR and AC in patients with CKD. METHODS: We recruited 91 men aged > or =60 years with GFR 15-89 ml/min (mean 47 +/- 21) to evaluate the relationship between GFR and AC in a cross-sectional study. We measured AC at the brachial artery with an oscillometric device (brachial artery distensibility; BAD). RESULTS: There was no correlation between GFR and BAD (r = 0.08, p = 0.44). When stratified according to CKD stages, all groups showed decreased BAD compared with reference values, and there were no differences among them (one-way ANOVA). Bivariate analyses showed statistically significant correlations between BAD and age (r = -0.23, p = 0.03), antihypertensive drug number (r = 0.27, p = 0.009) and serum hemoglobin (r = 0.24, p = 0.02), but only age and antihypertensive drug number remained significant markers of BAD in a multiple regression model. CONCLUSION: Older men with CKD have impaired arterial function, but GFR and CKD stage have no relationship to the degree of decrease in brachial artery distensibility.