Faculty Bibliography

OBJECTIVE: The objective of this study was to compare pre-dialysis and post-dialysis hemoglobin (Hgb) and ultrafiltration in hemodialysis patients. Factors influencing Hgb are not well understood. METHODS: Pre-dialysis and post-dialysis Hgb and weight were measured in 133 hemodialysis patients. Absolute and percentage change in Hgb (%Delta Hgb) and percent change in body weight (%Delta BW) were determined for that treatment. Patients were divided into 2 groups, those with post-dialysis Hgb <13 g/dL (group 1) and those with post-dialysis Hgb >= 13 g/dL (group 2); the differences in %Delta BW were compared between the 2 groups. RESULTS: The mean pre-dialysis Hgb was 11.9 +/- 1.4 g/dL, the mean post-dialysis Hgb level was 12.8 +/- 1.8 g/dL. The %Delta Hgb was 3.9 +/- 6.6 in group 1 and 10.8 +/- 7.8 in group 2. The %Delta BW was 3.1 +/- 1.4 in group 1 and 3.9 +/- 1.7 in group 2 (p < .001 for all comparisons), We found that although both groups had a rise in Hgb level post-dialysis, group 2 patients had a rise in %Delta Hgb that was greater than the relatively small difference in %Delta BW between the 2 groups. In addition, we found only a modest correlation between %Delta BW and %Delta Hgb in both groups. The r(2) of 0.24 suggests that only 25% of the variability found in %Delta Hgb can be related to %Delta BW. CONCLUSIONS: Patients with post-dialysis Hgb >= 13 g/dL had a greater increase in %Delta Hgb that was out of proportion to %Delta BW. Factors other than %Delta BW may play a role in determining post-dialysis Hgb.

A 36 year-old 5 weeks postpartum lactating woman presented to the emergency room with severe nausea and vomiting for 48 hours. The patient was found to be in non-diabetic ketoacidosis with a serum pH 6.9 and a HCO3 of <5mEq/L. This condition rapidly improved with the administration of intravenous dextrose and bicarbonate and with the cessation of breast feeding. The course and pathophysiology of the rarely described phenomenon of bovine ketosis in a human is discussed here.

Hyponatremia has been shown to be associated with gait disturbances, decreased mentation, and falls. The study objective was to determine the incidence of hyponatremia in patients who experienced a substantial skeletal fracture (hip/pelvis/femur). During an 18-month period from March 2007 to August 2008 serum sodium levels were evaluated in 364 cases of bone fracture in patients aged 65 years or older and in 364 nonfracture patients aged 65 years and older seen in an urban emergency room setting. The incidence of hyponatremia in patients with fractures was more than double that of nonfracture patients (9.1% and 4.1%, respectively; P = 0.007). The degree of hyponatremia was noted to be mild to moderate. Mean serum sodium of the entire fracture group was 131 +/- 2 mEq/L. In the fracture group the patients were 75.3% female, while females comprised 66.2% of the nonfracture group (P = 0.02). Of fracture patients with hyponatremia, 24.2% were taking antidepressants [3/4 of which were selective serotonin receptor inhibitors (SSRIs)], while none were taking these medications in the nonfracture group. Attention regarding careful follow-up of serum sodium levels in elderly patients seems appropriate

BACKGROUND: The effect of continuing or discontinuing chronic angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) therapy prior to coronary angiography on the incidence of contrast-induced nephropathy (CIN) is not clear. We undertook a randomized trial to evaluate the effect of withdrawing ACEIs or ARBs 24 h prior to coronary angiography on the incidence of CIN associated with coronary angiography. METHODS: A total of 220 patients with chronic kidney disease (CKD) stages 3-4 (glomerular filtration rate 15-60 ml/min/1.73 m2) on ACEI or ARB therapy were randomized before angiography to either ACEI/ARB continuation group or discontinuation group. A third group of patients with CKD stages 3-4 but not on angiotensin blockade therapy were also followed. The primary outcome measure was the incidence of CIN defined by a rise in serum creatinine by 25% or 0.5 mg/dl (44 micromol/l) from baseline. RESULTS: There was no statistically significant difference in the incidence of CIN between the three groups (P=0.66). The incidences were 6.2%, 3.7%, and 6.3% for the continuation, discontinuation, and angiotensin blockade naive group, respectively. There was also no significant difference found between the groups in mean serum creatinine and glomerular filtration rate values at baseline and post contrast administration. CONCLUSION: Withholding ACEIs and ARBs 24 h before coronary angiography does not appear to influence the incidence of CIN in stable patients with CKD stages 3-4

The treatment of hyponatremia, especially euvolemic and hypervolemic hyponatremia, has changed with the development of drugs which function as vasopressin receptor antagonists. These agents increase solute-free water excretion by the kidney resulting in an aquaresis. Conivaptan, a vasopressin receptor antagonist, has recently been approved by the FDA in the United States for use in the therapy of both euvolemic and hypervolemic hyponatremia. This report summarizes one center's experience with ten patients treated with this new drug. The patients had euvolemic hyponatremia with serum sodium levels less than 128 mEq/l. The same protocol was used in all patients with the conivaptan being given as a 20-mg intravenous loading dose followed by a 20-mg continuous 24-h infusion. Review of the data revealed that six of the ten patients had an excellent response to the therapy, with serum sodium increasing by a mean of 8.5+/-0.8 mEq/l (increases ranged from 7 to 12 mEq/l over 24 h). No significant changes in serum potassium levels or mean arterial pressures were noted. Two of the ten patients experienced a decrease in urine osmolality without a significant increase in serum sodium. Two other patients had only slight decreases in urine osmolality, and no significant increase in serum sodium levels. The data reveal that conivaptan is useful in the management of significant hyponatremia. There were no significant untoward effects, with the exception of one patient whose blood pressure decreased during the conivaptan infusion and who responded to cessation of the infusion and saline replacement therapy. This new class of drugs holds great promise for the treatment of dilutional hyponatremic disorders

The prevalence of iron deficiency and its contribution to the anemia of end stage renal disease has been extensively studied, but much less is known about the role of iron deficiency in the pathogenesis of the anemia of chronic kidney disease in predialysis patients. All new hemodialysis patients entering a single hemodialysis unit between July 1999 and April 2002 were included in the study. The admission laboratory tests and the Health Care Financing Administration (HCFA) 2728 form were examined to determine the prevalence of erythropoietin use, anemia (Hb<11 g/dl), and iron deficiency (ferritin<100 ng/ml and transferrin saturation %<20%). In a second part of the study, the effect of intravenous iron gluconate replacement in patients with stage III & IV chronic kidney disease was examined. Anemia was present in 68% of all patients starting hemodialysis. Iron deficiency was a common feature occurring in 29% of patients taking erythropoietin (49% of all patients) and 26% of patients without erythropoietin (51% of all patients). Following the administration of intravenous iron gluconate to four patients, there was a significant rise in hemoglobin levels from 10.6+/-0.19 to 11.7+/-g/dl (p=0.02). Conclusion: Iron deficiency is common in predialysis patients. Replenishing iron stores in anemic patients with chronic kidney disease significantly increases hemoglobin levels and should be considered as an integral part of the therapy for treating anemia in the predialysis population

BACKGROUND: Patients on hemodialysis are at high risk for cardiovascular disease (CVD). Aspirin is an established therapy for primary and secondary prevention of CVD that may be underutilized in hemodialysis patients. To better understand the use of aspirin in hemodialysis patients, we examined the experience of an urban hemodialysis center. Guidelines for use as well as associated risks and benefits are reviewed. METHODS: Medical records for patients receiving hemodialysis treatment at our center (New York City, USA) in May 2004 were reviewed for aspirin use, presence of CVD, and potential contraindications to aspirin therapy. CVD was defined as a history of coronary artery disease, ischemic stroke, transient ischemic attack, or peripheral vascular disease. Potential contraindications to aspirin therapy included history of clinically significant bleeding or increased risk of bleeding, aspirin allergy and routine treatment with other anticoagulants. RESULTS: 176 patients were eligible for the study and 172 (98%) were included. Although 74 patients had a history of CVD, only 38 (51 %) of these were treated with aspirin. Among patients with a history of CVD who were not treated with aspirin, 19 (53%) had no identifiable contraindications to aspirin therapy for secondary prevention of CVD. Ninetyeight patients had no history of CVD, and 18 (18%) of these were treated with aspirin. Of patients without a history of CVD who were not treated with aspirin, 57 (71%) had no identifiable contraindications to aspirin therapy for primary prevention of CVD. CONCLUSIONS: Aspirin is underutilized in hemodialysis patients for the primary and secondary prevention of CVD. Given the high risk of CVD in hemodialysis patients, therapy with aspirin may be of significant benefit and prospective studies of aspirin therapy are needed