Prospective study on clinical effects of renal replacement therapy in treatment-resistant congestive heart failure.

BACKGROUND/AIMS: Clinical outcome in cardiorenal syndrome (CRS) Type 2 and treatment with dialysis. METHODS: Prospective observational non-randomized study. RESULTS: Twenty-three patients were included, mean age 66±21 years. Twelve (52%) patients were treated with peritoneal dialysis (PD) and 11 (48%) with intermittent haemodialysis (IHD). Median survival time after start of dialysis was 16 months. Hospitalizations for cardiovascular causes were reduced (1.4±0.6 pre-dialysis versus 0.4±0.6 days/patient/month post-dialysis, P=0.000), without significant changes in hospitalization for all causes (1.8±1.6 versus 2.1±2.9 days/patient/month). New York Heart Association (NYHA) class (3.8±0.4 at start versus 2.4±0.7 after 4 months, P=0.000, versus 2.7±0.9 after 8 months, P=0.001) and quality of life tended to improve (63±21 at start, versus 41±20 after 4 months, versus 51±25 after 8 months; P=0.056). Left ventricular ejection fraction did not change. The number of technical complications associated with dialysis therapy was relatively high in this population. CONCLUSIONS: After starting dialysis for CRS, hospitalizations for cardiovascular causes were reduced, but not hospitalizations for all causes. Functional NYHA class improved and quality of life tended to improve, without evidence for a change in cardiac function. In this small study, no differences between IHD and PD were observed.

Hemodynamic response to lower body negative pressure in hemodialysis patients.

BACKGROUND: Hypovolemia is thought to have an important role in the pathogenesis of dialysis-related hypotension. METHODS: We studied the effect of hypovolemia simulated by lower body negative pressure (LBNP) in 11 hypotension-prone (HP) and 11 hypotension-resistant (HR) hemodialysis patients. LBNP was applied stepwise from 0 to -20 to -40 mm Hg. Systolic arterial pressure, heart rate, and central venous pressure (CVP) were recorded continuously after cannulation of the right jugular vein. Stroke volume index was measured at each step echocardiographically. At the end of each level of LBNP, blood samples were obtained to measure norepinephrine (NE), epinephrine (E), and atrial natriuretic peptide (ANP) levels. RESULTS: At baseline, CVP (12 +/- 5 and 16 +/- 7 mm Hg), heart rate (72 +/- 9 and 70 +/- 13 beats/min), cardiac index (2.3 +/- 0.6 and 2.5 +/- 0.9 L/min), NE (median, 341 pg/mL [range,198 to 789 pg/mL] and 365 pg/mL [range, 177 to 675 pg/mL] or 2.02 nmol/L [range, 1.17 to 4.66 nmol/L] and 2.16 nmol/L [range, 1.05 to 4.00 nmol/L]), E (median, 46 pg/mL [range, 18 to 339 pg/mL] and 58 pg/mL [range, 21 to 122 pg/mL] or 251 pmol/L [range, 98 to 1,951 pmol/L] and 317 pmol/L [range, 115 to 666 pmol/L]) were similar, whereas systolic arterial pressure (141 +/- 26 versus 164 +/- 22 mm Hg) and ANP (median, 441 pg/mL [range, 152 to 1,330 pg/mL] versus 804 pg/mL [range, 517 to 3,560 pg/mL] ng/L) were lower (P < 0.05) in HP patients. In response to LBNP (-40 mm Hg), CVP decreased by 6.5 +/- 4.0 mm Hg in the HP group and 4.9 +/- 4.9 mm Hg in the HR group. In HP patients, this decrease was associated with a greater decrease in SI (37% +/- 16% versus 27% +/- 16%) and systolic arterial pressure (19% +/- 21% versus 4% +/- 14%) than in HR patients. Plasma ANP levels did not change, whereas increases in NE and E levels were similar in HP and HR patients. CONCLUSION: Patients who frequently experience episodes of hypotension during dialysis also are prone to develop hypotension during LBNP, which results from reduced myocardial contractile reserve and/or inadequate sympathetic tone.

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.