Gadolinium-based MR contrast agents and nephrogenic systemic fibrosis.
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Clinical Trials as Topic↗
Biomedical subjects
Ali K Abu-Alfa
Publications and source records attributed to Ali K Abu-Alfa.
Long-term comparison of sevelamer hydrochloride to calcium-containing phosphate binders.
AIM: In patients with end-stage renal disease (ESRD), hyperphosphataemia and an elevated calcium-phosphorus (Ca-P) product contribute to morbidity and mortality. Suggested target goals for serum phosphorus concentration and calcium-phosphorus product have recently been lowered. As a result, long-term comparative studies of the efficacy of phosphate binders are critical. This study compares the long-term efficacy of sevelamer hydrochloride to calcium-containing binders (CCB). METHODS: A retrospective chart review was conducted in 30 patients receiving sevelamer hydrochloride for >1 years and 25 patients receiving CCB. RESULTS: Patients on sevelamer hydrochloride had lower serum bicarbonate concentration than those on CCB, 18.6 +/- 2.7 versus 20.3 +/- 1.8 mmol/L (P = 0.0017). Serum phosphorus concentration was higher in patients on sevelamer hydrochloride compared to CCB 2.10 +/- 0.87 versus 1.74 +/- 0.28 mmol/L (P = 0.0013), as was the Ca-P product 4.97 +/- 0.94 mmol2L2 (62.1 +/- 11.8 mg2/dL2) versus 3.97 +/- 1.18 mmol2/L2 (49.7 +/- 14.7 mg2/dL2), P = 0.0009). Only 36% of patients on sevelamer hydrochloride compared with 68% on CCB (P = 0.015) met the serum phosphorus goal of < or =1.78 mmol/L. CONCLUSION: Patients on sevelamer hydrochloride for >1 years compared to those on CCB had a lower serum bicarbonate concentration, a higher serum phosphorus concentration and a higher Ca-P product. Clinicians should balance the increase in calcium load with CCB versus the cost and effectiveness of sevelamer hydrochloride in choosing a phosphate binder for ESRD patients.
Acetates↗
Cinacalcet for secondary hyperparathyroidism in patients receiving hemodialysis.
BACKGROUND: Treatment of secondary hyperparathyroidism with vitamin D and calcium in patients receiving dialysis is often complicated by hypercalcemia and hyperphosphatemia, which may contribute to cardiovascular disease and adverse clinical outcomes. Calcimimetics target the calcium-sensing receptor and lower parathyroid hormone levels without increasing calcium and phosphorus levels. We report the results of two identical randomized, double-blind, placebo-controlled trials evaluating the safety and effectiveness of the calcimimetic agent cinacalcet hydrochloride. METHODS: Patients who were receiving hemodialysis and who had inadequately controlled secondary hyperparathyroidism despite standard treatment were randomly assigned to receive cinacalcet (371 patients) or placebo (370 patients) for 26 weeks. Once-daily doses were increased from 30 mg to 180 mg to achieve intact parathyroid hormone levels of 250 pg per milliliter or less. The primary end point was the percentage of patients with values in this range during a 14-week efficacy-assessment phase. RESULTS: Forty-three percent of the cinacalcet group reached the primary end point, as compared with 5 percent of the placebo group (P<0.001). Overall, mean parathyroid hormone values decreased 43 percent in those receiving cinacalcet but increased 9 percent in the placebo group (P<0.001). The serum calcium-phosphorus product declined by 15 percent in the cinacalcet group and remained unchanged in the placebo group (P<0.001). Cinacalcet effectively reduced parathyroid hormone levels independently of disease severity or changes in vitamin D sterol dose. CONCLUSIONS: Cinacalcet lowers parathyroid hormone levels and improves calcium-phosphorus homeostasis in patients receiving hemodialysis who have uncontrolled secondary hyperparathyroidism.
Calcium↗
Vascular access surveillance: evaluation of combining dynamic venous pressure and vascular access blood flow measurements.
BACKGROUND/AIMS: Vascular access thrombosis is one of the most morbid problems encountered by hemodialysis patients. Surveillance protocols utilizing venous pressure (Vp) and vascular access blood flow (VABF) measurements have been employed to preserve vascular access. We undertook a study to evaluate combined dynamic Vp and VABF measurements in the identification of vascular access impairment. We also assessed the effect of preventive repair on thrombosis rates in impaired vascular accesses identified by surveillance. METHODS: Eighty-six chronic hemodialysis patients with a functioning vascular access were enrolled into the surveillance protocol. All vascular accesses with greater than 50% of monthly Vp readings >120 mm Hg or VABF <500 ml/min in arteriovenous fistulas (AVFs) and VABF <650 ml/min in arteriovenous grafts (AVGs), or a decrease in VABF >25% compared to the highest previously measured value, were considered positive. Stenosis >50% on fistulography or a thrombotic event were defined as a 'vascular access impairment episode' while a stenosis <50% or the absence of a thrombotic event was defined as 'no vascular access impairment episode'. Thrombosis rates and intervention rates were calculated per access year at risk. RESULTS: The sensitivity and specificity of the combined surveillance protocol for AVFs were 73.3 and 91%, respectively. In AVGs, they were 68.8 and 87.5%, respectively. The rate of thrombotic events was lower in patients who underwent early repair. The addition of dynamic Vp did not reduce the thrombosis rate any further than surveillance based on VABF alone. CONCLUSION: Combined monitoring for surveillance of AVFs improved sensitivity but had little benefit in AVGs over VABF monitoring alone. Raising VABF cutoff levels might increase and improve identification of vascular access risk for thrombosis, but at the expense of lower specificity.
Arteriovenous Shunt, Surgical↗
Addition of sertraline to other therapies to reduce dialysis-associated hypotension.
Sertraline has shown promise in the treatment of dialysis-associated hypotension (DAH) in a limited number of end-stage renal disease patients. We undertook a study to evaluate the effect of adding sertraline to other therapies for patients with documented DAH. We also measured the effect of sertraline on intradialytic haemodynamics. We used the ultrasound dilution technique (HD01 monitor) to measure cardiac output (CO), central blood volume (CBV) and peripheral vascular resistance (PVR) in these patients. The study was performed in two phases. Phase 1 was a control, while the second phase consisted of treatment with sertraline (50 mg/day). Cardiac output and central blood volume were measured 30 min following the initiation of dialysis and 30 min prior to the termination of dialysis. Blood pressure (BP) was monitored during haemodynamic measurements and throughout dialysis. Eighteen patients with documented DAH completed the study. Cardiac output, CBV and PVR were no different in the sertraline phase as compared with the control phase. The declines in systolic BP, diastolic BP and mean arterial pressures from pre-haemodialysis (HD) to lowest intradialytic and pre-HD to post-HD were not significantly different for the sertraline phase versus the control phase. In conclusion, it appears that sertraline has no additive effect on intradialytic haemodynamics to improve blood pressure in patients with DAH who are under therapy (with sodium modelling, cool dialysate and midodrine).
Adult↗
Approach to fluid management in peritoneal dialysis: a practical algorithm.
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Algorithms↗
Hemodynamics in patients with intradialytic hypotension treated with cool dialysate or midodrine.
Cool dialysate and midodrine have been used successfully to treat intradialytic hypotension (IDH) in the end-stage renal disease population. However, the exact mechanisms by which these interventions improve hemodynamic stability are not well known. We undertook a study to evaluate the effect of these modalities on intradialytic hemodynamics in patients with documented dialysis-associated hypotension. We used the ultrasound dilution technique to measure cardiac output (CO), central blood volume (CBV), and peripheral vascular resistance (PVR) in these patients. The study was performed in two phases. Phase 1 consisted of control (1A) and cool dialysate (1B) studies, whereas phase 2 consisted of control (2A) and midodrine (2B) studies. CO, CBV, and PVR were measured 30 minutes after the initiation of hemodialysis (HD) and 30 minutes before the termination of HD using the HD01 monitor. Blood pressure was measured pre-HD and post-HD. Fourteen patients with documented IDH completed the study. CO and CBV were significantly more preserved in the cool dialysate and midodrine phases compared with control phases. PVR increased in all phases of the study. Declines in mean arterial pressures from pre-HD to post-HD were less with cool dialysate versus control and midodrine versus control. Ultrafiltration volumes were not significantly different between phases. Cool dialysate and midodrine appear to improve intradialytic hemodynamics in patients with dialysis-associated hypotension, mainly through the preservation of CBV and CO, rather than significantly elevating PVR.
Adrenergic alpha-Agonists↗
Angiotensin-converting enzyme inhibitors and anemia in chronic kidney disease: a complex interaction.
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Anemia↗
Observations on HIV-associated renal disease in the era of highly active antiretroviral therapy.
BACKGROUND: Renal disease in patients infected with HIV has evolved to include several lesions, including HIV-associated nephropathy (HIV-AN), which can promote progressive loss of renal function. Although angiotensin-converting enzyme inhibitors and corticosteroids are beneficial in selected patients, the effect of highly active antiretroviral therapy (HAART) on renal function is currently being explored. METHODS: We undertook a retrospective study to determine the types of renal lesions present in patients infected with HIV with renal insufficiency and/or proteinuria during the era of HAART availability and the effect of HAART on renal outcomes in these patients. Patients with HIV infection referred to the renal clinic from July 1996 through December 2000 were evaluated. Patient characteristics and data were collected including CD4 count, viral load, serum creatinine, blood pressure, proteinuria, renal ultrasound, and biopsy results, and treatment with HAART. Study endpoints were doubling of serum creatinine, initiation of dialysis, or death. RESULTS: Twenty-three patients met study criteria, 13 received HAART, and 10 did not. Baseline characteristics were similar except for renal function parameters, viral loads, and CD4 counts. A variety of lesions were noted on 12 renal biopsies. A clinical diagnosis of HIV-AN was made in the other 11 patients. Only 2 patients receiving HAART before renal evaluation were noted to have HIV-AN. In the HAART group, none of the patients, including those with HIV-AN, developed a doubling of serum creatinine. In the non-HAART group, all patients manifested a doubling of serum creatinine, 2 patients died, and 8 patients required dialysis. CONCLUSIONS: A variety of renal lesions are noted in patients infected with HIV during the HAART era. Patients who received HAART maintained stable renal function, whereas patients who did not required dialysis therapy or died with advanced renal failure. It seems that HAART may improve renal outcomes in patients with HIV and renal disease.
AIDS-Associated Nephropathy↗