Increase in serum creatinine in a patient on continuous peritoneal dialysis: potential mechanisms and management.

A large elevation in serum creatinine (S(Cr)) on an unchanged peritoneal dialysis (PD) schedule is usually caused by a decrease in total creatinine clearance (C(Cr)), but may also reflect an increase in creatinine (Cr) production. A meticulously compliant 43-year-old man with lupus nephritis on automated nocturnal PD plus an additional daytime exchange developed a rise in S(Cr) to 16.73 mg/dL from 8.06 mg/dL after starting fenofibrate, while total C(Cr) decreased only to 61.5 L/1.73 m2 from 77.4 m2 weekly. Creatinine excretion was 16.4 mg/(kg x 24 h) pre-fenofibrate. It increased to a high of 26.2 mg/(kg x 24 h) during the period of fenofibrate intake and returned to 21.9 mg/ (kg x 24 h) 2 months after discontinuation of that drug. The patient's age, weight, height, body mass index, 24-h drain and urine volumes, total Kt/V urea, serum urea nitrogen, urea nitrogen excretion, and (for the pre-fenofibrate period) S(Cr), Cr excretion, estimated Cr production, and measured-to-predicted Cr excretion (using a formula developed in PD patients) were within the 95% confidence intervals (CIs) obtained in a control group of 24 other men on similar PD schedules. The patient's Cr excretion and production were above the 95% CIs of the control group while he was on fenofibrate, and they returned toward or within the 95% CIs after cessation of the drug. The patient's serum creatine phosphokinase was not elevated while he was taking fenofibrate. A thorough investigation of the potential mechanisms of a rise in S(Cr) during the course of PD is warranted to determine if the rise is disproportional to any fall in total C(Cr). In the latter case, Cr excretion and production should be evaluated, and if elevated, conditions potentially causing the rise in Cr production (fenofibrate in this patient) should be sought, and appropriate therapeutic interventions should be implemented.

Development of Renal Failure without Proteinuria in a Patient with Monoclonal Gammopathy of Undetermined Significance: An Unusual Presentation of AL Kappa Amyloidosis.

AL amyloidosis complicating monoclonal gammopathy of undetermined significance (MGUS) has usually a predominant glomerular deposition of lambda light chain. Heavy proteinuria is one of its cardinal manifestations. A 78-year-old man with a 9-year history of IgG kappa light-chain-MGUS and normal urine protein excretion developed severe renal failure. Serum levels of kappa light chain and serum IgG had been stable while proteinuria was absent throughout the nine-year period. For the first eight years, he had stable stage III chronic kidney disease attributed to bladder outlet obstruction secondary to prostatic malignancy. In the last year, he developed progressive serum creatinine elevation, without any increase in the serum or urine levels of paraproteins or any sign of malignancy. Renal ultrasound and furosemide renogram showed no evidence of urinary obstruction. Renal biopsy revealed AL amyloidosis, with reactivity exclusive for kappa light chains, affecting predominantly the vessels and the interstitium. Glomerular involvement was minimal. Melphalan and prednisone were initiated. However, renal function continues deteriorating. Deposition of AL kappa amyloidosis developing during the course of MGUS predominantly in the wall of the renal vessels and the renal interstitium, while the involvement of the glomeruli is minimal, leads to progressive renal failure and absence of proteinuria. Renal biopsy is required to detect both the presence and the sites of deposition of renal AL kappa light chain amyloidosis.

Hemodialysis catheter infection with unusual presentation and grave outcome.

Bacteremia from central venous catheter (CVC) infection causes morbidity and mortality in patients on hemodialysis (HD). Diagnosis of the infection can be difficult and may require special imaging. A 70-year-old man with diabetic nephropathy was on HD for 11 months through a permanent CVC. Because of symptomatic osteoporosis, he had kyphoplasty in three lumbar vertebrae (L2, L3, L4) 6 months after starting HD. Severe back pain persisted after kyphoplasty. Throughout the HD period, the exit site of the CVC had a clean appearance, there was no fever, and blood leukocyte counts were normal. During the 11th month of HD, he complained of subjective fever at home. Blood count revealed normal leukocyte count with neutrophilic predominance and blood cultures grew methicillin-resistant Staphylococcus aureus (MRSA). Echocardiogram revealed no heart valve vegetations, but irregular thickening of the CVC wall. Fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET-CT) revealed severe inflammation of the CVC wall and a picture consistent with osteomyelitis and severe destruction of the body of the 11th thoracic vertebra. He was treated with intravenous vancomycin and removal of the CVC, the wall of which was grossly inflamed and grew in culture MRSA. Three weeks later, he discontinued HD because of persistent severe back pain. CVC infection with bacteremia and remote infectious foci having grave sequelae can develop in HD patients with paucity of clinical manifestations. FDG-PET-CT is a useful imaging tool in establishing the presence and extent of both the CVC infection and remote metastatic infectious foci.

Age-related blood pressure patterns and blood pressure variability among hemodialysis patients.

BACKGROUND AND OBJECTIVES: Despite the high prevalence of cardiovascular disease among hemodialysis patients, the relationship between age and blood pressure (BP) is not well understood. It was postulated that the relationship of BP to age differs among hemodialysis patients versus the general population and that there is significant variability in dialysis unit BP measurements. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: To explore this hypothesis, the patterns of systolic, diastolic, mean arterial, and pulse pressures in the general population using data from National Health and Nutrition Examination Survey participants (n = 9242) were compared with those in a cohort of hemodialysis patients (n = 9849). RESULTS: In contrast to the increase in systolic BP with age in the general population, systolic BP was elevated in young hemodialysis patients and declined slightly among the elderly. The inverted "U"-shape relationship between age and diastolic BP in the general population was absent in hemodialysis patients. Diastolic BP was elevated among hemodialysis patients <50 yr of age and declined with advancing age. Mean arterial and pulse pressures were elevated among young hemodialysis patients and exhibited less age dependency than in the general population. Variability in BP within patients was similar to that between patients. CONCLUSIONS: The relationship of BP to age differed from that in the general population. The variability in dialysis unit BP measurements may limit their use in managing hypertension and predicting outcomes. Nevertheless, dialysis unit BP measurements are necessary to minimize acute complications during the dialysis procedure.