Long-term outcomes of revascularization for peripheral vascular disease in end-stage renal disease patients.

The occurrence of peripheral vascular disease (PVD) and atraumatic lower-extremity amputations is significantly greater in patients with end-stage renal disease (ESRD) than those with normal renal function. Moreover, the mortality for dialysis patients undergoing atraumatic lower-extremity amputations is far greater. Because PVD requiring amputation is an extreme form of PVD, we tested the hypothesis that mortality and intermediate outcomes for patients with ESRD undergoing lower-extremity revascularization, a less extreme form of PVD, would be equivalent to that for patients without ESRD. This is a retrospective case-control analysis of lower-extremity revascularization in patients with ESRD. Procedures in patients with ESRD were matched with procedures in non-ESRD controls for patient age, sex, race, diabetes mellitus, and hospital setting. Patient survival, graft survival, and limb salvage rates were determined using Kaplan-Meier analysis. Subjective interpretation of functional and symptomatic improvement was determined by telephone interviews with patients or relatives. Thirty-one procedures were performed on 20 patients with ESRD and 64 matched procedures were performed on 57 patients without ESRD. In the ESRD group, median patient survival was 1.72 years compared with 5.17 years for the control group (P < 0.001). Time to 50% limb loss was 1.24 years in the ESRD group and longer than 5.65 years in the control group (P < 0.001). Time to 50% graft patency loss was 0.70 years in the ESRD group and longer than 5.5 years in the control group (P < 0.05). Subjective improvement was less in patients with ESRD. Outcomes of lower-extremity revascularization in patients with ESRD are inferior to those in non-ESRD controls. The mortality rate for patients with ESRD who undergo revascularization is extremely high. Patient-related variables (eg, increased prevalence of hypertension and cardiovascular disease) and/or provider-specific factors (eg, timing of surgery in the course of PVD) may be responsible for poorer outcomes.

Activity of phospholipase A2 in plasma increases in uremia.

We measured phospholipase A2 (PLA2; EC 3.1.1.4) activity in normal and uremic plasma, using [1-14C]oleate-labeled autoclaved Escherichia coli as substrate. Hydrolysis of bacterial phospholipid by crude plasma from both groups was optimal at pH 5.5, was specific for the 2-acyl position of phospholipids, and had an absolute requirement for calcium. Activity was greatest in the presence of added Ca2+, 5 mmol/L, but this increase was inhibited by several divalent cations (Mg2+, Zn2+, Cu2+, Ba2+, Co2+, Pb2+, Fe2+) and by Fe3+. PLA2 activity was also inhibited by heparin at acid and alkaline pH, normal plasma being more sensitive than uremic plasma to this inhibition. Enzyme activity in undiluted plasma was eightfold greater in uremic than in normal plasma. Dilution of plasma by two to fourfold increased the total activity of both normal and uremic plasma. However, the relative differences in total activity between the groups remained constant (eight- to 11-fold). The cause and consequences of the increased PLA2 activity in uremia remain to be established.

A prospective study of infections in hemodialysis patients: patient hygiene and other risk factors for infection.

We performed a prospective randomized study on 71 patients on chronic outpatient hemodialysis to determine whether a sterile technique was better than a clean technique for preparation of the skin over the vascular access site prior to cannulation. In addition, we wanted to determine overall and site-specific infection rates, microbial etiologies of infection, and risk factors for infection. The overall infection rate was 4.7 infections per 100 dialysis months; the vascular access-site infection rate was 1.3 infections per 100 dialysis months; and the rate for bacteremia was 0.7 cases per 100 dialysis months. Staphylococcus aureus was the most common pathogen, but infections were equally divided between gram-positive cocci and gram-negative bacilli. Advanced age (P = 0.02), a low Karnofsky activity score (P = 0.05), poor hygiene (P = 0.0004) and number of hospitalizations (P = 0.0002) were risk factors for infections in general while only poor hygiene (P = 0.002) was a risk factor for vascular access-site infection. Sterile preparation of the skin over the vascular access site was no more effective at preventing infection than was clean technique (P = 0.80). Maintenance of good personal hygiene may be one of the most important measures for prevention of infections in hemodialysis patients.

Determination of oxalate concentration in blood.

The methods used for determination of oxalate in blood are reviewed, and the advantages and disadvantages of the two basic approaches--direct methods and in vivo isotope-dilution techniques--are compared. Possible reasons for the previous discrepancies between direct and isotopic methods are discussed, as are the effects of protein binding, sample handling, and storage conditions on oxalate values in plasma. Necessary precautions for obtaining reproducible results are presented. We recommend and critically review several direct methods, and describe the application of a direct method for oxalate determination in some other biological fluids.

Prospective study of microbial colonization of the nose and skin and infection of the vascular access site in hemodialysis patients.

We conducted a prospective study of nasal and skin floras in 71 patients receiving chronic hemodialysis. We wished to determine whether a sterile skin preparation technique was more effective than a clean technique in removing microorganisms from the skin of the vascular access site. We also examined the effect of administration of antibiotics and status of patient hygiene on microbial flora. The presence of Staphylococcus aureus in the nose had a low predictive value for the simultaneous presence of the microorganism on the skin. The status of skin colonization can be accurately assessed only by culture of the skin. Sterile technique was no more effective at removing microorganisms from skin than was clean technique. Antibiotics significantly affected nasal flora but not skin flora. S. aureus was significantly more likely to remain on the skin after application of an antiseptic in patients with poor hygiene than in patients with good hygiene (P = 0.002). Patients with poor hygiene also had a significantly higher concentration of S. aureus on the skin of the vascular access site after application of antiseptic than patients with good hygiene (P = 0.005). We found no evidence to support a change from clean to sterile technique for skin preparation, but improvement in personal hygiene may be an effective strategy for prevention of vascular access infections.

Total volume culture technique for the isolation of microorganisms from continuous ambulatory peritoneal dialysis patients with peritonitis.

A total volume method of culturing dialysis fluid from continuous ambulatory peritoneal dialysis patients during episodes of peritonitis was developed. Concentrated culture media stored in small blood transfer bags were added directly to the drained dialysate exchange bags by the same technique used to carry out the dialysate exchange. The exchange bag with the added culture medium was incubated at 35 degrees C and observed for turbidity. Seventy-eight dialysis exchange bags from patients without clinical peritonitis (negative controls) and forty-eight dialysis exchange bags from patients with clinical peritonitis were cultured. Bacteria were recovered from all cultures of patients with clinical peritonitis (100% sensitivity) and from five cultures of negative control fluids (94% specificity). Of these isolates, 86% were gram positive, and 14% were gram negative. This technique represents an advance over previously described culture techniques in its ability to isolate the causative organism(s) in cases of peritonitis in continuous ambulatory peritoneal dialysis patients.

The effect of acetate and bicarbonate dialysis on orthostatic blood pressure regulation.

Dialysis-induced hypotension is probably due to multiple factors which reduce cardiac output and peripheral vascular resistance. That acetate, used in dialysate as a source of bicarbonate, may be one of these factors is suggested from several studies which show improved blood pressure regulation with bicarbonate-containing dialysate. We have further examined this hypothesis by comparing supine and standing blood pressure changes in nine stable patients during dialysis with acetate or bicarbonate solutions. Although mean weight changes were not different, standing blood pressure was lower after acetate dialysis. Such a hypotensive effect of acetate could result from depression of the force of myocardial contraction and/or from a reduction in peripheral vascular resistance.

Effects of 1,25-dihydroxyvitamin-D3 on renal function, mineral balance, and growth in children with severe chronic renal failure.

To confirm and extend previous observations of enhanced linear growth in children with chronic renal disease being treated with 1,25-dihydroxyvitamin-D3 and to characterize further the calcium, phosphorus, magnesium, and zinc disorders in renal failure, 11 children (mean age 8 +/- 5 years) with chronic renal insufficiency (glomerular filtration rate 18% +/- 13% of normal) were evaluated on the basis of their reciprocal serum creatinine concentrations, height-velocity curves, mineral balances, and radiologic findings. Reciprocal serum creatinine concentrations analyzed retrospectively and prospectively during 32 months of 1,25-dihydroxyvitamin-D3 therapy showed progression of renal failure at rates linearly identical with those before treatment, thus suggesting that the treatment did not accelerate the rate of deterioration of glomerular filtration rate in chronic anal insufficiency. Indeed, one patient manifested a lesser decline in renal function (P less than .05). The height velocity of six of the children (75%) less than 12 years of age improved markedly over that expected for chronologic and bone ages after one year of treatment with orally administered 1,25-dihydroxyvitamin-D3, 15 to 35 ng/kg/day. All other medications except vitamin D2 were continued at their pretreatment dosage levels throughout the study. Growth velocity was unimproved in two of three children older than 12 years at the initiation of 1,25-dihydroxyvitamin-D3 therapy. Mineral balance data showed significant retention of calcium, phosphorus, magnesium, and zinc (357 +/- 32 mg/sq m/day, 250 +/- 82 mg/sq m/day, 38 +/- 32 mg/sq m/day, and 1,157 +/- 283 microgram/sq m/day, respectively), after treatment for 12 months. In addition, serum calcium, alkaline phosphatase, and parathyroid hormone concentrations returned toward normal. Finally, healing of renal osteodystrophy was radiologically evident after six months of therapy.

A 3-year survey of referral pattern and case material in pediatric nephrology.

A 3-year survey of patient referrals and case material in pediatric nephrology is evaluated to provide a data base for future projection of patient needs. In the 3-year period between January 1978 to December 1980, 538 pediatric patients with renal and electrolyte disorders were evaluated and treated. The principle reasons for the referrals were: hematuria (23%), hypertension (5%), nephrotic syndrome (7%), non-acute glomerulopathies (11%), acute glomerulonephritis (3%), fluid-electrolyte disorders (29%), urinary tract infections (6%), and others. Of the 538 patients, 99 underwent percutaneous renal biopsies under ultrasound guidance. The indications and results of the renal biopsies were also reviewed. The accrual of 18 chronic dialysis patients over a 36-month period is analyzed and presented. The ages of the patients were 4 to 16 years. They weighed from 16 to 51 kg. The primary renal diseases were objective uropathy, chronic glomerulonephritis, membrano-proliferative nephritis, chronic pyelonephritis, focal glomerulonephritis, lupus nephritis and others. All children, except 9 received kidney transplantations. The annual incidence of end-stage renal failure was 4 per million population.

Rapidly progressive glomerulonephritis in Behçet's syndrome.

Rapidly progressive glomerulonephritis developed in a patient with Behçet's syndrome while he was being treated with transfer factor. The therapy did not prevent development of this disease and thus cannot be recommended in patients who have Behçet's syndrome with renal involvement.

The pathogenetic significance of intravascular coagulation in experimental acute renal failure.

Serum and urine fibrin(ogen) degradation products (FDP), FDP clearances, and serum urea nitrogen (SUN) concentrations of rats challenged with glycerol-induced myohemoglobinuria were measured serially over a period of 4 days. The results obtained in animals that developed acute renal failure (ARF) were compared with those obtained in rats made refractory to renal failure by long-term salt loading or recent recovery from prior renal failure. Only the rats susceptible to ARF experienced a major rise in serum FDP concentration. Urine FDP excretion rose most markedly in the same rats but, being elevated in all groups. showed the utilization of fibrinogen whether serum FDP values increased or not. The results obtained might reflect differences in the degree of intravascular coagulation which are pathogenetically important. It is possible, however, that increased serum FDP concentrations found exclusively in rats with ARF are the results rather than the cause of impaired filtration, and that reduced tubular absorption may at least partly account for the high urinary FDP excretion observed in this model of experimental acute renal failure.

Renin release and the refractoriness to acute renal failure of rats recovering from prior renal failure.

Renin substrate concentrations and the release of renin in response to the rapid removal of 15 ml/kg weight blood or subcutaneous administration of 500 microgram/kg body weight isoproterenol were measured in control rats and animals recovering from prior myohemoglobinuric acute renal failure (recovery rats). Blood for these assayas was drawn from chronically implanted aortic catheters, obviating the need for animal handling and anesthesia. Baseline plasma renin titers of recovery rats were modestly elevated but renin substrate concentrations were the same as in controls. Hemorrhage produced equivalent changes in blood pressure and plasma renin titer in the two groups. Isoproternol injection in recovery rats caused a somewhat greater blood pressure fall and almost twice the rise in plasma renin concentration observed in control rats. The marked resistance of recovery animals to a second bout of acute renal failure thus cannot be attributed to impaired renin release or inadequate plasma renin substrate.

Micropuncture studies of the filtration and absorption of albumin by nephrotic rats.

The proximal tubular fluid albumin concentration of rats with immunologically induced nephrotic syndrome rose from 0.60 +/- 0.11 (SEM) mg/100 ml to 7.42 to 0.87 mg/100 ml. The glomerular filtration rate (GFR) was slightly depressed (P less than 0.001) and fractional water absorption unchanged (P greater than 0.45). Urinary albumin excretion rose from 0.18 +/- 0.03 (SEM) mg/100 g of body wt/24 hr to 78.5 +/- 39.5 mg/100 g/100 g of body wt/24 hr (P less than 0.001). The concentration of albumin in glomerular filtrate, calculated as the product of proximal tubular albumin concentration and fractional water absorption (4.53 +/- 0.60 mg [SEM]/100 ml), equalled that calculated from urine albumin concentration and whole kidney water absorption (4.14 +/- 0.84 mg/100 ml, P greater than 0.30). The data are interpreted to reflect a significant increase in filtered albumin and only a modest (if any) tubular albumin absorption in this study. Thus, the concept that tubular absorption plays a major role in the catabolism of albumin and the genesis of hypoalbuminemia in the nephrotic syndrome could not be confirmed.