Effect of a dietitian-managed bone algorithm on serum phosphorus level in maintenance hemodialysis patients.

OBJECTIVE: This study examined the effectiveness of a registered dietitian (RD)-managed bone metabolism algorithm compared with a non-RD (registered nurse and the nephrologist)-managed one on serum phosphorus (PO4) and related clinical outcomes (corrected serum calcium [cCa] level, intact parathyroid hormone [iPTH] level, incidence of parathyroidectomy) among in-center maintenance hemodialysis (MHD) patients. DESIGN AND SETTING: The study was an 18-month retrospective review of adult MHD patients (n = 252) at 5 outpatient dialysis centers in western Massachusetts and Connecticut before and after change in the management of a comprehensive bone metabolism treatment algorithm (intravenous vitamin D, phosphate-binding medication, calcimimetic) from non-RD to RD. Calendar-matched timepoints representing 3-month averages during the non-RD- and RD-managed periods of the same algorithm were used for analyses. Comparisons of outcomes at non-RD-managed timepoint 2 (February 2009-April 2009) and RD-managed timepoint 6 (February 2010-April 2010) were performed considering potential demographic and clinical confounders. RESULTS: On average, serum PO4 level was lower during the RD-managed timepoint 6 (5.17 ± 1.23 mg/dL; mean ± standard deviation) compared with non-RD-managed timepoint 2 (5.23 ± 1.24 mg/dL), although the difference between these calendar-matched timepoints was not statistically significant (F = .108, P = .74) after controlling for age, dietary intake (equilibrated normalized protein catabolic rate), and dialysis adequacy (equilibrated Kdrt/V). Mean cCa at RD-managed timepoint 6 (8.76 ± 0.65 mg/dL) was not significantly different from non-RD-managed timepoint 2 (8.79 ± 0.74), and the difference between serum iPTH level at timepoint 6 (363.0 ± 296.8 pg/mL) compared with timepoint 2 (319.8 ± 251.5 pg/mL) was nonsignificant (F = .650, P = .42) after controlling for age. There were fewer parathyroidectomies during the RD-managed period (0.8%) compared with the non-RD-managed period (1.6%). CONCLUSIONS: RDs may be equally effective as non-RDs in bone metabolism algorithm management with respect to serum PO4, cCa, and iPTH control in MHD patients. Further research is needed to prospectively evaluate the effect of RD management on these bone mineral outcomes.

Nutritional effects of delivered bicarbonate dose in maintenance hemodialysis patients.

OBJECTIVE: Metabolic acidosis is common in patients with end-stage renal disease (ESRD). Studies suggest that correction of acidosis may improve nutritional status and patient outcomes. The purpose of this study was to examine the effects of increasing delivered bicarbonate dose from 35 mmol/L to 39 mmol/L with respect to nutrition-related outcomes in maintenance hemodialysis patients (MHD). DESIGN AND SETTING: This was a longitudinal, observational study conducted at 4 dialysis centers in western Massachusetts. Patients were followed for 6 months after change in bicarbonate dose protocol. PATIENTS: The study sample consisted of 248 patients who had been on MHD for at least 1 year on the standard bicarbonate dialysate of 35 mmol/L without oral bicarbonate supplements. MAIN OUTCOME MEASURES: Measures of interest included predialysis serum bicarbonate, albumin, hemoglobin, potassium, phosphorus, calcium, and parathyroid hormone (iPTH), as well as protein catabolic rate (nPCR). A subset of patients (n = 35) was examined for changes via Subjective Global Assessment (SGA). RESULTS: Serum bicarbonate improved significantly from baseline (21.7 +/- 2.8 mmol/L; mean +/- SD) at 3 months (23.3 +/- 3.3) and 6 months (23.1 +/- 3.3) (P <.0001). Phosphorus decreased from 6.0 +/- 2.0 mmol/L at baseline to 5.7 +/- 1.7 mmol/L (P =.02) at 6 months, although calcium, iPTH, and potassium remained relatively stable. Serum bicarbonate was inversely and significantly correlated with nPCR at baseline (r = -0.23; P <.05) and 3 months (r = -0.22; P <.05). The nPCR decreased significantly (P =.001) from baseline (0.99 +/- 0.26) at 6 months (0.93 +/- 0.23), whereas the serum albumin and SGA scores did not differ. CONCLUSION: Increasing delivered bicarbonate dose improves serum bicarbonate and may decrease catabolism. Further study is needed to confirm the potential nutritional benefits.

Emergence of gentamicin-resistant bacteremia in hemodialysis patients receiving gentamicin lock catheter prophylaxis.

BACKGROUND AND OBJECTIVES: Antibiotic locks in catheter-dependent chronic hemodialysis patients reduce the rate of catheter-related blood stream infections (CRIs), but there are no data regarding the long-term consequences of this practice. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Over a 4-year period, from October 1, 2002, to September 30, 2006, we initiated a gentamicin and heparin lock (GHL) protocol in 1410 chronic hemodialysis patients receiving dialysis through a tunneled catheter in eight outpatient units. RESULTS: Within the first year of the GHL protocol, our CRI rate decreased from 17 to 0.83 events per 1000 catheter-days. Beginning 6 months after initiation of the GHL protocol, febrile episodes occurred in 13 patients with coagulase-negative Staphylococcus bacteremia resistant to gentamicin. Over the 4 years of GHL use, an additional 10 patients developed 11 episodes of gentamicin-resistant CRI (including 7 with Enterococcus faecalis), in which there were 4 deaths, 2 cases of septic shock requiring intensive care unit admission, and 4 cases of endocarditis. Because of these events, the GHL protocol was discontinued at the end of 2006. CONCLUSIONS: Although the use of GHL effectively lowered the CRI rate in our dialysis population, gentamicin-resistant CRIs emerged within 6 months. Gentamicin-resistant infections are a serious complication of the long-term use of GHLs. Alternative nonantibiotic catheter locks may be preferable to decrease the incidence of CRIs without inducing resistant pathogens.