Vascular calcification and atherosclerosis in hemodialysis patients: what can we learn from the routine clinical practice?

BACKGROUND: Hemodialysis (HD) patients are at increased risk for arterial intimal (AIC) and medial calcification (AMC). METHODS: In a cross-sectional study on 153 HD patients we evaluated the presence of AIC and AMC using plain radiography of the pelvis and the presence of atherosclerotic lesions using high-resolution B-mode ultrasonography of the common carotid arteries (CCA). RESULTS: The radiography of the pelvis confirmed the frequent presence of AIC (35.3%) and AMC (35.9%) in our HD patients. Arterial calcification was absent (non calcified-NC) in a minority of patients (28.8%). Patients with AIC had significantly higher prevalence of atherosclerotic plaques on CCA (78.6%) compared with both other groups and a higher number of documented atherosclerotic complications, such as cardiovascular (85.2%), cerebrovascular (33.3%) and peripheral arterial disease (38.9%) in comparison with the NC patients. According to the 1-year calculated data from patient records, there were no significant differences in the specific HD risks, such as the dose of prescribed calcium carbonate and vitamin D3, serum levels of calcium, phosphate, calcium-phosphate product and intact parathyroid hormone. All four bone metabolism markers within the range proposed by K/DOQI guidelines were achieved in 9.3%, 14.5% and 20.4% in the AIC, AMC and NC group, respectively. CONCLUSIONS: Patients with AIC and AMC are frequently found in the HD population. Screening for arterial calcifications in chronic kidney disease patients is suggested even in the early pre-dialysis period. The highest proportion of patients within the guidelines proposed range for bone and mineral metabolism markers was observed in the NC group. A longer period of data analysis is required in order to evaluate the possible role of some traditional and HD-specific risk factors for the development of arterial calcifications. The achievement of the K/DOQI guidelines is an important issue in the prevention of those conditions.     

Can the DOQI guidelines be met by peritoneal dialysis alone in pediatric patients?

DOQI guidelines recommend minimal standards for automated peritoneal dialysis (APD), with a weekly Kt/V of 2.1 and creatinine clearance (C _Cr) of 63 l/1.73 m². The purpose of this study was to assess if the DOQI guidelines could be met by dialysis alone in children on PD. Dialysis clearance studies were retrospectively analyzed in 20 pediatric patients on APD, all with a dwell volume of at least 1,000 ml/m². Mean dialytic Kt/V was 2.0; only 45% had a Kt/V above the recommended 2.1. Mean dialytic C _Cr was 43.5 l/week per 1.73 m²; only 10% achieved a C _Cr above the recommended 63 l/week per 1.73 m². Despite the significant correlation between total therapy volume (TTV) and both Kt/V and C _Cr, only 2 of 10 patients with a TTV over 10 l/m² per day reached the target C _Cr. All patients had currently recommended dwell volumes, therapy times, and nocturnal cycles, but DOQI guidelines were difficult to achieve with dialysis alone. Strict adherence to DOQI guidelines in anephric pediatric PD patients may result in changing dialysis modality. However, without evidence of a correlation between delivered dose of dialysis and improved outcome, adequate dialysis should not be assessed by only measuring Kt/V and C _Cr. Received: 24 June 1999 / Revised: 2 November 1999 / Accepted: 2 November 1999     

Application of NKF-K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease: changes of clinical practices and their effects on outcomes and quality standards in three haemodialysis units.

BACKGROUND: The K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease was published in October 2003. The objective of this study was to analyse the effect of the application of those guidelines on clinical practices and on the achievement of bone disease targets and quality standards. METHODS: We included in the study 342 patients dialysed in our three HD units during 2003 and 2004. Starting October 2003, the K-DOQI recommendations were introduced into practice. Parathyroid hormone (PTH) was measured every 3 months and the serum Ca and P levels, monthly. In patients whose medications were modified, PTH was measured monthly and Ca and P levels, weekly or biweekly. RESULTS: The following are the main findings for 2004 (post-K/DOQI): an increased use of dialysates with a Ca concentration of 2.5 mEq/l (27.2-50.9%, P<0.001) and a reduced use of a dialysate calcium of 3.0 mEq/l (44.6-39.6%, P: NS) and 3.5 mEq/l (28-9.4%, P<0.001); a reduced use of calcium-based phosphate binders (891.9-565.5 mg Ca/day, P<0.001) and increased use of sevelamer hydrochloride (800 mg) (from 4.86 to 7.51 mg, tablets/day, P<0.001) lower serum Ca levels (9.7-9.4 mg/dl, P<0.01), and higher intact PTH levels (201.4-311.8 pg/ml, P<0.001), without changes in serum P levels; an increased proportion of patients with serum Ca levels within the K/DOQI target range (38.7-46.6%, P<0.01), resulting mainly from the reduced percentage of patients with hypercalcaemia (55-44.4%, P<0.01); a decreased proportion of patients with PTH<150 pg/ml (53.8-31.4%, P<0.001) but an increased proportion of patients with PTH>300 pg/ml, with no change in the proportion of patients with PTHs within the K/DOQI target range. Phosphorus levels and targets did not show significant differences between 2003 and 2004 (56.9-56.2%, P: NS). CONCLUSIONS: The only way to ensure that K/DOQI guidelines actually improve medical outcomes is to emphasize implementation strategies and also the scientific evaluation of their effectiveness in clinical settings. In spite of the application of the K-DOQI recommendations, a large proportion of our patients stayed outside the proposed targets, which points to the need for more effective therapeutic options.     

Institution of a Hospital-Based Central Venous Access Policy for Peripheral Vein Preservation in Patients with Chronic Kidney Disease: A 12-Year Experience

PurposeTo describe the implementation of nursing-based venous access team (VAT) and standardized interventional radiology (IR) protocols in accordance with Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines to provide central venous access while preserving peripheral veins in patients with chronic kidney disease (CKD).Materials and MethodsReview of peripherally inserted central catheter (PICC) and small-bore central catheter (SBCC) referral and placement data from VAT and IR databases was conducted over a 12-year period. SBCC referral was automatic for patients with creatinine levels ≥ 3 mg/dL or a renal transplant regardless of creatinine level unless dialysis was not planned. All SBCC insertions, regardless of referral source, were identified and reviewed, and SBCC placements prompted by K/DOQI PICC contraindication were identified. Catheter types, indications, access sites, technical success, and complications were ascertained.ResultsA total of 35,781 requests for PICC placement were made to the VAT; 1,889 (5%) were referred to IR for SBCC placement per institutional policy, and 2,200 SBCCs were attempted or newly placed during this period, 1,879 (85%) based on K/DOQI contraindications. Primary indication for SBCC placement was antibiotic therapy (59%). Access sites included right internal jugular vein (IJV) (70%), left IJV (24%), right external jugular vein (EJV) (3%), left EJV (2%), right common femoral vein (CFV) (0.3%), and left CFV (0.2%). Technical success rate of SBCC insertion was 99%. Six minor (0.3%) and three major (0.1%) complications occurred.ConclusionsAutomatic referral for SBCC placement in patients with CKD via VAT and IR protocols may eliminate PICC placement and thereby protect peripheral veins needed for hemodialysis. SBCC placement has high technical success and low complication rates.     

Problems in adapting the K/DOQI guidelines for Japanese patients with end stage renal failure

The National Kidney Foundation published The K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in Chronic Kidney Disease. We should also consider differences in clinical features of management for renal osteodystrophy between Japan and the USA. The first problem is related to a difference in the method of Ca correction. The second problem is related to a difference in the timing of measurement. In the USA the timing of measurement varies with each institution. Briefly, it is performed at midweek (2 days after the last dialysis) in some of institutions, while at the beginning of next week (3 days after the last dialysis) in some others. In addition, differences in the dose and type of the calcium-containing phosphorus adsorbent and active vitamin D used should also be taken into consideration.     

Efficacy of percutaneous ethanol injection therapy for secondary hyperparathyroidism in patients on hemodialysis as evaluated by parathyroid hormone levels according to K/DOQI guidelines

Secondary hyperparathyroidism (SHPT) is a major complication of hemodialysis patients. Recently, percutaneous ethanol injection therapy (PEIT) has become a useful alternative treatment to parathyroidectomy (PTx). In this study, we evaluate the usefulness of PEIT for SHPT according to Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. We studied 28 patients on hemodialysis with high intact-PTH (>400 pg/mL) and one to four swollen parathyroid glands detected by power Doppler ultrasonography. They were classified into Group 1 (N = 16), with 1 or 2 swollen glands, Group 2 (N = 5), with 3 or 4 swollen glands, and Group 3 (N = 7), high-risk patients for PTx. We compared serum intact-PTH levels 1 year after PEIT according to K/DOQI guidelines among these groups. We also evaluated the effectiveness of PEIT and PTx by comparing intact-PTH levels in 21 patients 1 year after PEIT (groups 1 and 2) with 11 patients after PTx. In Group 1, adequate intact-PTH levels were noted in 13 of 16 (81.2%) patients after PEIT, while 1 patient of 5 (20%) was achieved in Group 2, and 2 of 7 (28.6%) patients of Group 3. Adequate intact-PTH levels were attained in 14 of 21 (66.7%) patients of the PEIT group but only in 2 of 11 (18.2%) patients of the PTx group. Our results suggest that PEIT is a useful treatment for SHPT, especially in patients with one or two swollen glands. Through appropriate selection of patients for PEIT and correct injection of ethanol into the enlarged parathyroid gland, PEIT could accomplish better outcomes based on K/DOQI guidelines.     

Cinacalcet hydrochloride therapy for secondary hyperparathyroidism in hemodialysis patients

This study compared the efficacy of a cinacalcet‐based regimen with unrestricted conventional therapy (vitamin D and phosphate binders) for achieving Kidney Disease Outcome Quality Initiative (K/DOQI) targets for dialysis patients. In this multicenter, prospective study, hemodialysis patients with poorly controlled secondary hyperparathyroidism (SHPT) were randomized to receive a cinacalcet‐based regimen (n = 55) or a conventional therapy (n = 27). Doses of cinacalcet, vitamin D sterols, and phosphate binders were adjusted during a 12‐week dose‐titration phase to achieve intact parathyroid hormone (iPTH) levels ≤ 31.8 pmol/L. The primary end point was the percentage of patients with values in this range during a 24‐week efficacy‐assessment phase. The clinical response to 36‐week cinacalcet treatment was evaluated. A dual energy X‐ray absorptiometry was performed before and after 36 weeks of cinacalcet therapy. Fifty‐eight percent of the cinacalcet group reached the primary end point, as compared with 19% of the conventional therapy group (P = 0.001). A higher percentage of patients receiving the cinacalcet‐based regimen versus conventional therapy achieved the targets for calcium, phosphorus and Ca × P. Achievement of targets was greatest in patients with less severe disease (intact PTH range, 31.8 to 53 pmol/L). Cinacalcet therapy increased proximal femur bone mineral density (BMD), but did not affect the lumbar spine. Itching intensity decreased significantly. Cinacalcet based treatment facilitates achievement of the K/DOQI targets for iPTH and bone mineral metabolism compared with conventional therapy in hemodialysis patients. Suppression of iPTH with cinacalcet reverses bone loss in the proximal femur. Cinacalcet alleviated itching.