A prospective comparison of three argatroban treatment regimens during hemodialysis in end-stage renal disease.

BACKGROUND: We prospectively evaluated 3 treatment regimens of argatroban, a direct thrombin inhibitor, for providing adequate, safe anticoagulation in patients with end-stage renal disease (ESRD) during hemodialysis. METHODS: In this randomized, 3-way crossover study, ESRD patients underwent hemodialysis sessions of 3- or 4-hour duration using high-flux membranes and each of 3 argatroban treatment regimens (A: 250-microg/kg bolus, with an additional 250-microg/kg bolus allowed; B: 250-microg/kg bolus followed by 2-microg/kg/min infusion; C: steady-state, 2-microg/kg/min infusion initiated 4 hours before dialysis). Pharmacodynamic effects including activated clotting times (ACTs); hemodialysis efficacy including single-pool Kt/V, urea reduction ratio (URR), and circuit flow; and safety through a 3-day follow-up were monitored. Argatroban pharmacokinetic parameters including dialytic clearance were evaluated during regimen C. RESULTS: Thirteen patients completed 38 hemodialysis sessions (1 patient withdrew consent after 2 sessions). Mean +/- SD ACTs increased from 131 +/- 14 seconds at baseline to 153 +/- 24, 200 +/- 30, and 197 +/- 33 seconds, respectively, after 60 minutes of hemodialysis using regimens A, B, and C. Across regimens, mean Kt/Vs (1.5-1.6) and URRs (70%-73%) were comparable. No dialyzer was changed; 1 session was shortened 15 minutes because of circuit clot formation. Systemic argatroban clearance increased approximately 20% during hemodialysis, without clinically significantly affecting ACTs. Upon argatroban discontinuation, ACTs and plasma argatroban decreased concurrently (elimination half-life, 35 +/- 6 min). No thrombosis, bleeding, serious adverse events, or clinically significant changes in vital signs or routine laboratory measures occurred. CONCLUSION: Argatroban, administered by each treatment regimen, provides safe, adequate anticoagulation to enable successful hemodialysis in ESRD patients. Argatroban dialytic clearance by high-flux membranes is clinically insignificant.

Hyperphosphatemia in dialysis patients: is there a role for focused counseling?

BACKGROUND: Elevated serum phosphorus (P) and calcium-P product (CaXP) are associated with cardiac mortality in dialysis patients. A CaXP <55 is considered acceptable by most authorities. Because nutrition practices can modulate CaXP, we designed a survey to study the impact of the patients' levels of education and disease awareness on their CaXP. METHODS: A survey questionnaire with 5 didactic questions pertaining to hyperphosphatemia and P-binders and 5 questions related to patient attitudes and beliefs was administered to all patients in a hemodialysis unit. The association of CaXP >55 with the patients' level of education, their score on the survey (didactic part, score 0 to 5), parathyroid hormone (PTH) levels, hyperkalemia, hypertension, and vascular disease were studied. RESULTS: Of the 117 patients (61 men, age 56.5 +/- 18 years) who participated in the survey, 49 (42%) had CaXP >55 and 100 (85%) were on P binders. Thirty-seven (31.6%) had at least some college education. Eighty-seven patients (74%) failed to identify foods rich in P; 61% were unaware of complications related to high CaXP. Patients with CaXP >55 were less likely to have college education (20% versus 39%, P =.04), and had lower survey scores (2.4 +/- 1.3 versus 2.6 +/- 1.4, P = NS). Patients with college education scored higher (2.9 +/- 1.1 versus 2.3 +/- 1.4, P =.014). Furthermore, CaXP >55 was significantly associated with hyperkalemia (P =.02), high PTH levels (P <.001), and hypertension (P =.02), but not with >Kt/V, URR, type of hemodialysis access, or vascular diseases. CONCLUSION: The majority of patients in the survey were ignorant of basic facts pertaining to high P and CaXP. The association of CaXP >55 with hyperkalemia, and not with Kt/V, suggests dietary noncompliance rather than inadequate dialysis. Patients with less education were more likely to have CaXP >55. Because this related mostly to misperception of simple facts that affect dietary habits, there is need for focused counseling of these patients at a level appropriate for their literacy skills.

Lytic therapy in central venous catheters for hemodialysis.

Over the past 2 decades the use of central venous catheters (CVCs) for hemodialysis has become commonplace. While these devices have provided much needed temporary access to the bloodstream, they often become thrombosed and require procedures to restore patency. This article examines the lytic enzymes that are currently available and focuses on the assessment and treatment of thrombosis.