Evaluation of serum anion gap in patients with liver cirrhosis of diverse etiologies

BACKGROUND

The low serum anion gap (AG) in patients with hepatic cirrhosis is generally attributed to hypoalbuminemia. Serum immunoglobulin G (IgG) (elevated in chronic viral hepatitis) and IgA (elevated in alcoholic cirrhosis) have different isoelectric points, and thus may affect serum AG in opposite directions.

AIM

To define the normal serum AG in patients with liver cirrhosis of diverse etiologies.

STUDY DESIGN

We retrospectively compared serum AG of 144 stable cirrhotics and 286 control patients (consecutive hospital admissions with serum creatinine concentration < 2 mg/dL).

RESULTS

Serum AG was significantly lower among the cirrhotics, compared to the controls (5.8 +/- 2.2 mEq/L vs. 7.0 +/- 2.2 mEq/L, respectively, p<0.005). However, when patients with serum albumin concentration < 3.5 g/dL were excluded, there was no significant difference between the cirrhotics vs. controls (6.7 +/- 1.8 mEq/L vs. 7.0 +/- 2.2 mEq/L, p=ns). Moreover, patients with liver cirrhosis secondary to chronic viral hepatitis had AG similar to that of the alcoholic cirrhotics (5.6 +/- 2.5 mEq/L vs. 6.0 +/- 1.9 mEq/L, p=ns). There was a positive correlation between serum albumin concentrations > 1.9 g/dL and serum AG, and a tendency toward an inverse correlation between serum globulin concentration and serum AG.

CONCLUSION

Our results support the contention that hypoalbuminemia accounts for the decreased serum AG frequently observed in patients with liver cirrhosis. We found no difference in serum AG with different causes of cirrhosis. We also suggest a lower reference range for normal serum AG.

Routine replacement of tunneled, cuffed, hemodialysis catheters eliminates paraspinal/vertebral infections in patients with catheter-associated bacteremia

BACKGROUND

Management of tunneled, cuffed, central venous catheters in hemodialysis (HD) patients with bacteremia remains a challenge. Attempts to salvage the catheter with systemic antibiotics alone have been associated with increased risk of metastatic infectious complications.

METHODS

Retrospective case series of patients with infectious complications in a chronic dialysis unit, affiliated with a tertiary care university hospital.

RESULTS

Between 1996 and 1999, when we treated HD catheter-associated bacteremia with systemic antibiotics alone, we encountered a clustering of 8 cases of paraspinal/vertebral infections in a population of 162 patients. After changing our protocol, i.e., routine catheter exchange over a guide wire at approximately 48 h, while on systemic antibiotic therapy, we did not encounter any new cases of paraspinal/vertebral infections over a 15-month period.

CONCLUSION

Our experience suggests that routine exchange of tunneled, cuffed catheters over a guide wire in HD patients presenting with bacteremia may significantly reduce serious infectious complications, e.g., epidural abscess/vertebral osteomyelitis.

Reversible acute renal failure associated with hypothyroidism: Report of four cases with a brief review of literature

We present four adult cases of acute renal failure associated with hypothyroidism. All patients presented with symptoms suggestive of moderate to severe hypothyroidism, such as cold intolerance, constipation, muscle weakness, and lower extremity oedema. Initial serum creatinine levels ranged between 115 and 203 micromol/L (1.3 and 2.3 mg/dL), with creatinine clearances (CrCl) ranging between 0.58 and 0.97 mL/s (34.5 and 58 mL/min). After 6-12 weeks of treatment with levothyroxin, serum creatinine levels decreased to the range of 80 and 124 micromol/L (0.9 and 1.4 mg/dL) and CrCl increased to 0.74-1.64 mL/s (44-98 mL/min). One patient had proteinuria of 800 mg/day, which decreased to the normal range (<200 mg/day) after levothyroxin treatment. One patient developed acute gouty arthritis before normalization of thyroid-stimulating hormone (TSH), which was successfully managed with prednisone therapy. All of our patients had increased creatine kinase (CK), ranging between 1000 and 2360 U/L (normal range, 22-165 U/L), which normalized after 6 weeks of levothyroxin treatment.

Incidence of side-effects associated with high-dose ferric gluconate in patients with severe chronic renal failure

Ferric gluconate complex in sucrose (Ferrlecit) has been associated with less side-effects than iron dextran; however, the recommended dose of 62.5-125 mg per treatment is only suitable for haemodialysis (HD) patients. We retrospectively analysed the incidence of the side-effects associated with a high dose of Ferrlecit infusion (20 treatments in 13 patients; 10 treatments of 250 mg/3-4 h, and 10 treatments of 500 mg/5 h infusion). The patients were in the age range of 32-75 years old, seven with chronic renal failure (CRF), and six on dialysis treatment. One (10%) of the 10 treatments using a 250 mg dose was complicated with severe nausea/vomiting, diarrhoea and a burning sensation in the feet. Three (30%) of the 10 treatments using a 500 mg dose were complicated with: chills, severe nausea/vomiting, hypotension and syncope in one; severe nausea/vomiting, diarrhoea and hypotension in one; and an episode of vomiting in one patient. A single treatment with a 250 mg dose resulted in no significant change in haematological parameters. A single treatment with a 500 mg dose resulted in a significant increase in haemoglobin (Hgb) and haematocrit (Hct), but only a rising trend in serum iron,% transferrin saturation and ferritin pre versus 1-2 months postinfusion. In conclusion, Ferrlecit doses of 250 or 500 mg are complicated with significant untoward reactions in 10-30% of patients, in a dose-dependent fashion.

Safety profile of a high dose ferric gluconate in patients with severe chronic renal insufficiency

BACKGROUND

Iron deficiency is a common and important cause of poor response to erythropoietin in patients with severe chronic renal failure (CRF). Oral iron supplements fail to correct iron deficiency in these patients. Ferric gluconate has a low side effect profile, however the recommended dose of 62.5 to 125 mg per treatment is not practical for patients who are not on hemodialysis (HD).

METHODS

We retrospectively analyzed the incidence rate of side effects associated with 250 mg of ferric gluconate infused over 1 to 4 hrs. Seventy-nine treatments were administered to 40 patients who had severe CRF. Five patients had received treatments on consecutive days (2 to 4 treatments).

RESULTS

Four treatments in two patients were associated with side effects, which included diarrhea, vomiting, low back pain, hypotension and burning sensation in feet. The duration of infusion did not influence the side effect profile.

CONCLUSION

Our preliminary results suggest that 250 mg of ferric gluconate infused over 14 hrs may be safe with infrequent side effects (5%). It is also more convenient and practical for patients who are not on maintenance HD.

Lack of reaction to ferric gluconate in hemodialysis patients with a history of severe reaction to iron dextran

Iron deficiency is the most common cause of a poor response to recombinant human erythropoietin (rHuEPO) in patients receiving long-term dialysis, who are known to absorb oral iron preparations poorly. This retrospective case series reports our preliminary observation of five patients receiving long-term dialysis in a tertiary care university hospital who had responded poorly to rHuEPO because of iron deficiency. These patients also had a history of severe, potentially life-threatening reaction to intravenous iron dextran preparation, but they tolerated the newly available ferric gluconate complex in sucrose with no untoward effects. These results suggest that the parenteral administration of ferric gluconate can be safe for those who require iron therapy and who have had a severe reaction to iron dextran.

Effect of reversal of catheter ports on recirculation: comparison of the PermCath with Tesio Twin Catheter

To study the effect of the reversal of the blood ports on blood flow rate (QB), percentage recirculation, and blood urea nitrogen (BUN) clearance, we compared 12 well functioning chronic hemodialysis catheters (7 PermCaths and 5 Tesio Twin Catheters) in both standard and reversed blood flow setups. The reversal of PermCath ports caused no change in the QB (307+/-20 ml/min vs. 314+/-9 ml/min, standard vs. reversed hook-up, respectively), but a significant increase in percentage recirculation (2.5+/-1.8% vs. 12+/-4.6%, standard vs. reversed hook-up, respectively, p = 0.02). Reversal of the Tesio Twin Catheter ports caused a significant decline in QB (296+/-13 ml/min vs. 250+/-16 ml/min, standard vs. reversed hook-up, respectively, p = 0.02), but no significant change in percentage recirculation (2.8+/-1.4% vs. 3.8+/-2.5%, standard vs. reversed hook-up, respectively, p = not significant). Reversal of the ports caused no significant change in BUN clearance with the PermCath (264+/-18 ml/min vs. 257+/-17, standard vs. reversed hook-up, respectively, p = 0.8), but a significant decline in BUN clearance with the Tesio Twin Catheter (247+/-11 ml/min vs. 216+/-13.5 ml/min, standard vs. reversed hook-up, respectively, p = 0.015). In conclusion, our results suggest that reversed hook-up of a well functioning Tesio Twin Catheter is associated with a significant decline in QB and BUN clearance, but no change in percentage recirculation; however, inadvertent reversed hook-up of a well functioning PermCath can lead to a considerable increase in percentage recirculation but no change in QB or BUN clearance.

Enoxaparin-associated severe retroperitoneal bleeding and abdominal compartment syndrome: a report of two cases

OBJECTIVE

To describe a complication of low-molecular-weight heparin (enoxaparin) in the setting of critically ill patients.

DESIGN

Case report.

SETTING

The medical and surgical intensive care units of a tertiary care university teaching hospital.

PATIENTS

Two adult patients receiving enoxaparin developed retroperitoneal hematoma and abdominal compartment syndrome. Both patients became anuric and required high-dose intravenous fluids and vasopressors to maintain blood pressure.

INTERVENTION

Discontinuation of enoxaparin, followed by exploratory laparotomy and evacuation of the hematoma.

MEASUREMENTS AND RESULTS

Immediate clinical improvement following evacuation of hematoma.

CONCLUSIONS

High-risk patients receiving low-molecular-weight heparin should be identified and closely monitored to prevent serious bleeding complications.

Helical CT angiography in evaluation of live kidney donors

BACKGROUND

Live kidney donor evaluation mandates anatomical and functional assessment of the donor kidney. Helical computed tomography (CT) with advanced 3-D techniques provides detailed description of the vascular, parenchymal, and collecting system.

METHODS

We compared the accuracy of helical CT angiography with intra-operative findings in the evaluation of 102 live kidney donors.

RESULTS

Identification of vascular anomalies was best on direct viewing of the axial images using interactive scrolling through the images and cine-loop paging. In 204 kidneys evaluated, a single renal artery was present in 74.5% and a single renal vein in 87.5%. Multiple renal arteries were more common on the left side (31%) vs the right side (20%). Early branching of the arteries was seen with equal frequency (approximately equal to 10%) on either side. Multiple renal veins were more often on the right side (20%) vs the left side (5%), and one patient was found to have double inferior vena cava. CT angiographic findings were concordant with the intra-operative findings in 97% of the cases, missing a small renal vein, an accessory artery that was visualized in retrospect, and a very early branch that was read as accessory artery. CT also revealed cortical cysts (four cases), duplex collecting system (two cases), hydronephrosis (one case), renal stone (one case), and liver haemangioma (two cases).

CONCLUSION

CT angiography is highly accurate for detecting vascular anomalies, and providing anatomical information. It may serve as the primary tool for donor evaluation.

Life threatening hyperkalemia and acidosis secondary to trimethoprim-sulfamethoxazole treatment

We present a 77-year-old male with moderate chronic renal insufficiency from diabetic nephropathy who developed severe metabolic acidosis and life threatening hyperkalemia on treatment with regular dose of trimethoprim-sulfamethoxazole (TMP-SMZ) for urinary tract infection. The metabolic acidosis and hyperkalemia resolved upon appropriate medical intervention and discontinuation of TMP-SMZ. While hyperkalemia has commonly been reported with high dose of TMP-SMZ, severe metabolic acidosis is quite uncommon with regular dose TMP-SMZ. We emphasize that patients with renal tubular acidosis (RTA), renal insufficiency, aldosterone deficiency, old age with reduced renal mass and function, and angiotensin converting enzyme (ACE)-inhibitor therapy are at high risk of developing these severe and potentially life threatening complications.

The effects of lipid-lowering agents on acute renal allograft rejection

BACKGROUND

Preliminary results from clinical trials suggest that 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors may help prevent acute renal allograft rejection. However, the mechanism for this putative effect of 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors, and whether it is independent of lipid-lowering per SE are unknown.

METHODS

Immediately after renal transplantation we randomly allocated (proportioned 2:1:2) patients to: 1) simvastatin (10 mg/day, n=53), 2) simvastatin placebo plus gemfibrozil (dose adjusted for renal function, n=36), and 3) simvastatin placebo (n=52).

RESULTS

Simvastatin, but not gemfibrozil, reduced total and low density lipoprotein cholesterol during the first 90 days posttransplant. There were no major adverse effects of therapy. However, there were no effects of treatment on acute rejection. Indeed, survival free of acute rejection at 90 days was 72% in the simvastatin group, 72% in the gemfibrozil group, and 77% in the placebo control group (P=0.771). A post hoc power analysis suggested that there was only a 7.5% chance that a true effect of simvastatin on acute rejection (versus placebo) was not detected, and a 2.5% chance that an effect of gemfibrozil on acute rejection (versus placebo) was not detected in this study.

CONCLUSION

Lipid-lowering agents may not reduce the incidence of acute renal allograft rejection. However, additional studies are needed to confirm this observation. In the mean time, many if not most renal transplant recipients should be treated with HMG-CoA reductase inhibitors starting early posttransplant to prevent cardiovascular disease complications. The results of this study suggest that starting lipid-lowering therapy immediately after renal transplantation is both safe and effective in lowering total and low density lipoprotein cholesterol.

Administration and clearance of amphotericin B during high-efficiency or high-efficiency/high-flux dialysis

Administration and clearance of amphotericin B infused during high-efficiency or high-efficiency/high-flux dialysis were studied in two end-stage renal disease patients requiring systemic antimycotic treatment for fungal peritonitis. Amphotericin B concentrations were measured in the arterial and venous dialysis ports as well as in the ultrafiltrate. Amphotericin B is poorly dialyzable while administered during hemodialysis sessions with high-efficiency (CA 210) or high-efficiency/high-flux (CT 190 G) membranes. Amphotericin B infusion during hemodialysis was well tolerated and can be administered conveniently in an outpatient dialysis setting, avoiding prolonged hospitalization for parenteral antifungal therapy.

Acute thrombosis of the renal transplant artery after a single dose of OKT3

We present the case of an 18-year-old male who 8 months after a living-related donor, one-haplotype-matched renal transplantation developed acute thrombosis of the renal allograft artery, within 10 h of the first dose of OKT3. The antibody therapy had followed five daily doses of intravenous pulse methylprednisolone for a Banff class 1B acute tubulointerstitial rejection, on a ciclosporin-based immunosuppression protocol. We briefly review the literature on the incidence of vascular thrombosis after transplantation and the procoagulant effects of OKT3, pulse methylprednisolone, and ciclosporin therapy.

Kidney disease in patients with chronic hepatitis C

There is an increasing recognition of the association between chronic hepatitis C virus infection and glomerular diseases. Renal complications may be the presenting manifestation of hepatitis C virus infection. Patients may present with signs and symptoms of cryoglobulinemic systemic vasculitis, proteinuria, microscopic hematuria, acute renal failure, or nephrotic syndrome. The pathogenesis of hepatitis C virus associated with renal disease remains incompletely understood; however, deposition of circulating immune complexes in the subendothelial space and mesangium in the glomeruli seems to play a major role. The most common renal pathology associated with hepatitis C virus infection is type I membranoproliferative glomerulonephritis with or without cryoglobulinemia. In patents who do not have significant renal impairment, combination therapy with interferon alfa (IFN-alpha) and ribavirin seems to be the treatment of choice, although the experience with this combination is quite limited in patients with renal involvement. A prolonged course of high-dose IFN-alpha has been most commonly used for these patients with significant success, but relapse of hepatitis C viremia and renal disease after discontinuation of therapy have frequently occurred.

Comparison of blood loss with different high-flux and high-efficiency hemodialysis membranes

Iron deficiency is a common problem in patients on chronic HD. Earlier studies have shown significant blood loss per HD session. To identify whether the new more biocompatible high-flux or high-efficiency membranes are also responsible for significant blood loss during HD, we quantitated the amount of blood loss associated with 4 commonly used membranes (F-50, F-80, CA-210, and CT-190). The residual blood in each compartment of extracorporeal circuit was quantitated after total lysis of the red blood cells (RBC), hemoglobin assay, and calculation of the RBC volume using the patient's hemoglobin and hematocrit concentrations just prior to the study. The average residual RBC volume in different membranes was 0.2-0.3 ml. The residual RBC volume in the dialysis lines (arterial or venous) was 0.1-0.2 ml and did not correlate with the residual RBC volume in the dialysis membranes. The residual RBC volume in the whole extracorporeal circuit (HD membrane, arterial and venous lines) ranged from 0.5 to 0.6 ml. It was significantly higher with F-50 vs. CA-210. The residual RBC volume in the dialysis membrane was significantly higher in the F-80 vs. CA-210 and CT-190 dialyzers. There was also significant difference in the residual RBC volume in the arterial lines of F-50 vs. CT-190, and F-50 vs. F-80 dialyzers.

CONCLUSION

Our results demonstrate for the first time that the total RBC loss per HD session is minimal in chronic HD patients.

Iron absorption after single pharmacological oral iron loading test in patients on chronic peritoneal dialysis and in healthy volunteers

OBJECTIVE

Oral iron is poorly absorbed in chronic dialysis patients. We tested the hypothesis that a superpharmacologic dose of iron sulfate (260 mg elemental iron) administered on an empty stomach results in significant iron absorption in these patients.

DESIGN

A prospective open controlled trial.

SETTING

Outpatient department of a university hospital.

PATIENTS

Nine stable chronic peritoneal dialysis (PD) patients and seven normal control subjects.

METHOD

All subjects ingested a single dose of 4 tablets of iron sulfate (260 mg elemental iron total) in the morning while fasting.

OUTCOME MEASURES

Serum iron concentrations at baseline, and at 2 and 4 hours after the oral dose were compared between the two groups.

RESULTS

The control group showed a significant rise in mean [standard error (SE)] serum iron concentration, from a baseline value of 76.5 +/- 7 microg/dL to 191 +/- 10.5 microg/dL at 2 hours and to 190 +/- 24 microg/dL at 4 hours. This result represents a percentage rise of 164% +/- 32% at 2 hours and 152% +/- 28.5% at 4 hours. In the PD patients, a significant rise in serum iron concentration was also seen, from a baseline value of 64 +/- 8 microg/dL to 130 +/- 3 microg/dL at 2 hours and 111 +/- 18 microg/dL at 4 hours. This result represents a percentage rise of 105% = 29% at 2 hours and 77% +/- 23.5% at 4 hours. However, the absolute change in serum iron concentration in PD patients at 2 and 4 hours was approximately equal to 50% of the change in control subjects at those time points. None of the PD patients experienced gastrointestinal side effects; 4 control subjects experienced mild side effects.

CONCLUSION

Despite impaired oral iron absorption in chronic dialysis patients, a large pharmacologic dose given orally can result in significant iron absorption and may prove to be a more efficient means of oral iron supplementation therapy in these patients.

Serum beta 2-microglobulin levels in patients chronically dialyzed with CA-210 versus CT-190 dialysis membranes

beta 2-Microglobulin (B2M) amyloidosis (dialysis-related amyloidosis), manifested primarily by carpal tunnel syndrome and destructive osteoarthropathy, is a major sequel of long-term dialysis. Previous investigators have shown that high-flux biocompatible synthetic membranes (e.g., polyacrylonitrile) lower beta 2M levels when compared to cellulosic membranes (e.g., cuprophane). To date, however, no study has compared beta 2M levels of patients dialyzed with the two more biocompatible cellulosic membranes CA-210 (cellulose acetate) and CT-190 (cellulose triacetate; high flux, more biocompatible). We retrospectively compared the serum beta 2M levels in two chronic hemodialysis populations: 22 patients on CT-190 and 21 patients on CA-210. There was no difference between the two groups with regard to age, sex, or duration of dialysis. The patients on the CA-210 membrane had significantly higher serum beta 2M levels (mean +/- SE; 53.6 +/- 4.7 vs. 36.8 +/- 2.6 mg/l, CA-210 vs. CT-190, respectively, p = 0.003). Subsequently we switched 13 patients dialyzed with a CA-210 membrane to a CT-190 membrane and followed serum beta 2M levels for 14 months. We found a significant decrease in serum beta 2M levels within 1 month which was maintained over 14 months of follow-up (47.4 +/- 4.4 vs. 62.8 +/- 6.7 mg/l, CT-190 at 14 months vs. CA-210 at baseline, respectively, p < 0.01).

Removal of acyclovir during continuous veno-venous hemodialysis and hemodiafiltration with high-efficiency membranes

We present a critically ill patient with severe renal failure and anuria who underwent hemodialysis (HD), continuous veno-venous hemodialysis (CVVHD) and continuous veno-venous hemodiafiltration (CVVHDF) at different occasions, with 2 commonly used high-efficiency dialyzers (F-8 and CA-210), while receiving i.v. acyclovir. We estimate that during 24 hours of CVVHD with F-8 dialyzer approximately 18% and during 24 hours of CVVHDF with CA-210 dialyzer approximately 65% of the daily administered acyclovir is removed. This is comparable to the amount removed during 4 6 hours of HD, as reported previously. The percentage acyclovir extraction was 84% and 60% during CVVHD and CVVHDF with F-8 and CA-210 dialyzers, respectively. Acyclovir clearance during CVVHD was 14 ml/min and during CVVHDF was 17 ml/min, with F-8 and CA-210 dialyzers, respectively. Acyclovir half-life was 22.5 and 25.5 hours in 2 occasions off any type of renal replacement therapy, and it was 19.5 hours during CVVHDF with CA-210 dialyzer.

Oxalate kinetics and reversal of the complications after orthotopic liver transplantation in a patient with primary hyperoxalosis type 1 awaiting renal transplantation

We present the case of a young woman with end-stage renal disease secondary to primary hyperoxaluria type 1, who after 3 years and 6 months of maintenance hemodialysis, and despite intensification of the dialytic treatment, developed severe livedo reticularis in her extremities leading to ischemic cutaneous ulcerations, necessitating continuous intravenous infusion of narcotics for pain control. She received a liver transplant after native hepatectomy. However, due to positive crossmatch, she could not receive a kidney from that donor. After transplantation, following serial serum oxalate levels, the hemodialysis regimen was safely reduced from 4 h daily to 3 h three times weekly. Over the course of 6 weeks after liver transplantation, her livedo reticularis resolved, the ischemic ulcers markedly improved, she was weaned off all pain medications, and her erythropoietin-resistant anemia resolved. Our results suggest that in patients with primary hyperoxaluria type 1, who have received a liver transplant and are on maintenance hemodialysis, after serial serum oxalate determinations, some may safely be changed to a thrice-weekly maintenance hemodialysis regimen. Moreover, with this regimen the complications of systemic oxalosis can reverse.

Nephrotic syndrome with mesangial proliferative glomerulonephritis induced by multiple wasp stings

We report the case of a young male who developed severe nephrotic syndrome within 2-3 weeks after being stung by 3 wasps. A percutaneous kidney biopsy specimen revealed mesangioproliferative glomerulonephritis with occasional subepithelial deposits suggestive of early membranous nephropathy. The patient was treated with oral prednisone 60 mg/day with no significant clinical response after 4 weeks, at which point he was started on oral cyclophosphamide, 100 mg/day, while the prednisone dose was tapered to 20 mg every other day over a 2-week period. Six months after initiation of cyclophosphamide, he still has severe nephrotic syndrome. We also briefly review the literature on Hymenoptera sting associated nephrotic syndrome.

Cimetidine-induced climacteric symptoms in a young man maintained on chronic hemodialysis

We present the case of a young man on maintenance hemodialysis who developed frequent episodes of 'fluttering, racing heartbeats', hot flashes, profuse sweating, anxiety, dizziness, and shortness of breath. These symptoms started approximately 1 month after taking cimetidine 400 mg/day with an occasional extra dose. His workup included a total of 72 h of cardiac monitoring, two-dimensional echocardiogram, and thyroid function tests, all of which were essentially unremarkable. When the drug cimetidine was temporarily discontinued, and on another occasion after the drug was totally withdrawn, the patient noticed marked improvement in his symptoms at 48 h with total resolution on the 5th day after discontinuation. This is the 2nd such case reported in the literature.

Insufficient penetration of systemic vancomycin into the PermCath lumen

BACKGROUND

Catheter infection is a major cause of morbidity and catheter loss in chronic haemodialysis patients. There has been a large discrepancy in the catheter salvage rate, after an episode of documented bacteraemia, whether the patients receive systemic antibiotic alone or systemic antibiotics concomitant with 'antibiotic-lock technique' (20-30% vs 100%, respectively). To test the hypothesis that vancomycin may not adequately penetrate into the lumen of the catheter, despite therapeutic plasma levels, a series of in-vivo, ex-vivo, and in-vitro experiments were performed.

METHODS

We compared serum and intralumenal (0.3-0.5 ml aspirate from venous port of the catheter) vancomycin concentrations in 24 chronic haemodialysis patients, with documented bacteraemia, who had received prior systemic vancomycin therapy with 14 similar patients who had additionally received 'vancomycin-lock technique' (100 microg/ml of vancomycin in heparin solution) after each haemodialysis session.

RESULTS

Despite serum vancomycin concentration of approximately 17 microg/ml in each group, the vancomycin concentration in the venous hub of the catheter was only 0.2+/-0.6 microg/ml in the former group, in sharp contrast to 125. 6+/-13 microg/ml in the latter group. In the ex-vivo experiment, four uninfected PermCaths which had been removed were immediately fixed and studied with scanning electron microscopy. No cellular or fibrin barrier could be found at the terminal pore of the catheter interfering with the diffusion of vancomycin from plasma into the catheter lumen. In the in-vitro experiments, three PermCaths filled with standard heparin solution were incubated for 48 h in 100 ml of plasma containing 20 microg/ml of vancomycin. Vancomycin concentration was measured in 0.3-0.5 ml solution aspirated from each port of the catheters. Vancomycin concentration was 0.2+/-0.1 microg/ml in the aspirated samples. Finally, two PermCaths filled with the standard heparin solution were incubated for 48 h in 100 ml of plasma containing 20 microg/ml of vancomycin, after which the catheters were sectioned at 4-cm intervals. Only the distal 4 cm of the catheters had vancomycin concentrations of 2 and 5 microg/ml, the remaining segments had levels </=0.5 microg/ml. CONCLUSION.: Our results indicate that diffusion of vancomycin from plasma into the haemodialysis catheter is negligible. Thus, haemodialysis patients with central venous catheter who have to be treated for bacteraemia with systemic antibiotic therapy must always receive 'antibiotic-lock technique' of the catheter after each haemodialysis session.

Delayed graft function complicated by spontaneous renal allograft rupture without acute rejection

We report a young male patient who developed spontaneous renal allograft rupture 7 days after cadaveric renal transplant, complicated by delayed graft function, without evidence of rejection on allograft biopsy.

Granulocyte-macrophage colony-stimulating factor as an adjuvant to hepatitis B vaccination in maintenance hemodialysis patients

Patients on maintenance hemodialysis (HD) have poor seroconversion rate after hepatitis B vaccination. The present study was designed to test the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant to hepatitis B vaccination for improving seroconversion rate in maintenance HD patients. Twelve chronic HD patients were randomly assigned to receive either hepatitis B vaccination alone or hepatitis B vaccination 24 h after 1 dose of GM-CSF for primary immunization. A group of 16 chronic HD patients who had not seroconverted after a standard two-dose hepatitis B vaccination were randomly assigned either to a booster dose of hepatitis B vaccine alone or a booster dose given 24 h after one dose of GM-CSF. In the primary immunization group only 2 of 6 patients (33%) who had received vaccination alone, versus 5 of 6 patients (83%) who had received hepatitis B vaccine after one dose of GM-CSF, developed seroprotective antibody titers. Moreover, seroprotective antibody titers (IU/ml) were significantly higher in the latter group (275 +/- 286.5 vs. 14 +/- 22, p < 0.05). In patients who had not seroconverted with prior hepatitis B vaccination, GM-CSF adjuvant therapy significantly increased the seroconversion rate versus booster dose alone (87.5 vs. 25%, respectively, p < 0.02), with significantly higher seroprotective antibody titers (84 +/- 80 vs. 19 +/- 33 IU/ml, respectively, p < 0. 05). These findings suggest that administration of one dose of GM-CSF, as adjuvant therapy, prior to primary or booster dose hepatitis B vaccination may significantly increase seroconversion rate and seroprotective antibody titers in chronic HD patients.

Successful treatment of normeperidine neurotoxicity by hemodialysis

Normeperidine, a major metabolite of meperidine, is half as potent as meperidine as an analgesic but two to three times more potent as a convulsant. Renal failure significantly increases the plasma half-life of normeperidine. The intensity of the central nervous system excitation is highly correlated with the plasma concentration of normeperidine. Moreover, normeperidine toxicity is not reversed by naloxone, which may exacerbate it. We report a patient with end-stage renal disease undergoing maintenance continuous cycler peritoneal dialysis who had been receiving meperidine for pain control. The patient subsequently developed myoclonic contractions and a grand mal seizure. The patient was successfully treated with hemodialysis (using an F8 dialyzer) for presumed normeperidine-induced seizure. During hemodialysis, normeperidine average blood clearance was 73 mL/min, average plasma clearance was 50 mL/min, and average percentage of plasma extraction was 24%. There also was a 26% reduction in plasma concentration of normeperidine over 3 hours of hemodialysis. In conclusion, our findings suggest that hemodialysis may be used effectively for treating patients with suspected normeperidine-induced neurotoxicity.

The effects of parathyroidectomy on nutritional and biochemical status of hemodialysis patients with severe secondary hyperparathyroidism

The nutritional and biochemical parameters of 15 chronic hemodialysis (HD) patients with severe secondary hyperparathyroidism who had undergone total parathyroidectomy (PTX), with a forearm implant, were retrospectively studied at 1, 3, 6, and 12 months pre- and post-PTX. The concentrations of serum calcium and phosphorous significantly decreased in the first 6 months post-PTX. The concentration of blood urea nitrogen significantly increased at 6 and 12 months post-PTX. In contrast with control chronic HD patients who had no weight gain after nonparathyroid surgery, there was a progressive weight gain leading to a significantly higher dry weight at 12 months post-PTX. There was no significant change in serum potassium, albumin, cholesterol, transferrin, bicarbonate, hematocrit, normalized protein catabolic rate (nPCR), or erythropoietin dose at any time point post-PTX. The biochemical parameters of the 8 patients who had more than 5% weight gain, during 12 months post-PTX, were not statistically different from the remaining 7 cases who had weight gain less than 5% (or had lost weight) in the same time period. The same was true for 4 patients with weight gain of more than 10% versus the latter group. In conclusion, HD patients with severe secondary hyperparathyroidism are prone to progressive weight gain post-PTX, which reaches significance by the twelfth month. In 53% of the patients, the weight gain is more than 5% above the baseline. The nutritional and biochemical parameters pre-PTX were not helpful in distinguishing those who developed significant weight gain post-PTX.

Intradialytic dobutamine therapy in maintenance hemodialysis patients with persistent hypotension

Intradialysis hypotension is a common problem, especially in patients with poor left-ventricular function. We studied 6 patients who were on maintenance hemodialysis with left-ventricular ejection fraction of <40%, whose dialysis sessions were often complicated with severe hypotension (systolic blood pressure <90 mm Hg). Dobutamine infusion during dialysis significantly reduced the number of hypotensive episodes, increased left-ventricular ejection fraction, and decreased the number of emergency admissions to the hospital.

Percutaneous renal biopsy in the 1990s: safety, value, and implications for early hospital discharge

To determine the parameters associated with significant bleeding and to examine the value of performing a renal biopsy, we studied 83 consecutive patients, including 24 renal allograft recipients, who had undergone percutaneous renal biopsy. The patients were stratified into four groups according to the percentage of decline in their hematocrit (Hct) at 24 hours postbiopsy, as follows: 10% or greater (n = 21; 25%) and less than 10% decline (n = 62; 75%). The latter group was further subgrouped into 5% to 10% (n = 22) and less than 5% decline (n = 40). There was a significant decline in Hct postbiopsy, with a linear correlation between the decrease in Hct at 6 and 24 hours (R2 = 0.47; P < 0.0001), suggesting that the former was a predictor of the latter. There was a linear correlation between the number of passes and number of cores obtained for the first four passes, but an inverse correlation when five passes or greater were required. Interestingly, there was no correlation between bleeding (>10% decline in Hct) and the number of passes or cores obtained. Gross hematuria and blood transfusion requirement were each encountered in three patients (3.6%). Importantly, the prebiopsy clinical diagnosis was altered in 18 of 59 native kidney biopsies (33%) and 10 of 24 transplant biopsies (41%). We conclude that percutaneous renal biopsy using an automated spring-loaded gun device coupled with ultrasound guidance is a safe technique and provides essential clinical information. Importantly, patients with a stable Hct at 6 hours were at low risk for bleeding at 24 hours while hospitalized. It remains to be determined if these findings could be extrapolated to early discharge from hospital.

Lupus nephritis in an anti-nuclear antibody-negative young male. The simultaneous presence of class III and class V renal lesions

We report about a 27-year-old white male, a known case of class III lupus nephritis with a very high anti-nuclear antibody (ANA) titer, who after 10 years of complete clinical and serological remission presented with sudden development of malar rash, proteinuria and an increase in the serum creatinine. Repeated serologic studies were all negative for ANA. A repeat kidney biopsy disclosed the presence of focal segmental glomerulosclerosis lupus nephritis (class IIIc) superimposed with a new membranous lupus nephritis (class V).

The impact of (1:1) cyclosporine A conversion to its microemulsion formulation on the kidney function of patients with cardiac allografts

Due to the large variations in the absorption and bioavailability of conventional cyclosporine A (CyA), 1:1 (mg:mg) conversion to its microemulsion formulation (Neoral) has been advocated in transplant recipients. However, the renal hazards and biochemical effects of such conversions and not known in cardiac transplant recipients. In this study, 68 cardiac transplant recipients who were receiving conventional CyA, for a period of 61.3 +/- 36.0 (mean +/- standard error (SE)) months, were switched to the microemulsion formulation (Neoral). The biochemical and renal function tests were evaluated at 1, 3, 6, 9 and 12 months pre- and post-conversion of CyA. The results obtained post-conversion were compared with those of the baseline (pre-conversion). Serum creatinine and uric acid levels significantly increased post-conversion to the microemulsion formulation. One patient required discontinuation of the microemulsion in an attempt to reverse severe renal failure. In spite of a significant decrease in the microemulsion dose at 6, 9 and 12 months, there was a significant increase in the whole blood CyA trough levels at 9 and 12 months of conversion. There was no significant change in blood pressure, serum total cholesterol or potassium post-conversion. Our results suggest that after 1:1 (mg:mg) conversion of CyA to its microemulsion formulation, there will be a significant rise in serum creatinine, uric acid and whole blood trough CyA levels necessitating significant dose reduction. This effect is probably due to the markedly improved absorption and bioavailability of the latter.

Acute reversible renal failure in a patient with paroxysmal nocturnal hemoglobinuria

We present the case of a young male with 2-month history of intermittent upper abdominal pain who developed diarrhea, anorexia, tea-color urine, and decreased urine output. He was found to be in severe acute renal failure requiring hemodialysis, four sessions in 10-day period. By the end of the second week of hospitalization renal function gradually improved with total recovery of function to a baseline creatinine of 1.1 mg/dl 25 days after the diagnosis of acute renal failure. His workup included Ham's test, water sugar test, and RBC fragility test which confirmed the diagnosis of paroxysmal nocturnal hemoglobinuria.

Quetiapine (Seroquel) in the treatment of psychosis in patients with Parkinson's disease

Psychoses are a common clinical problem in patients with Parkinson's disease. Treatment with typical neuroleptics or withdrawal of antiparkinsonian drugs may improve mental symptoms but will worsen the parkinsonism. Quetiapine (Seroquel), ICI 204,636, is a novel antipsychotic medication with a low potential for producing extrapyramidal side effects. In this open-label clinical study of 2 patients with Parkinson's disease, treatment with Seroquel successfully controlled psychotic symptoms without worsening of motor disability.

Removal of morphine with the new high-efficiency and high-flux membranes during haemofiltration and haemodialfiltration

We present three critically ill patients with severe renal failure who required haemofiltration or haemodiafiltration, with high-efficiency or high-flux membranes, while receiving an intravenous infusion of morphine. We show that despite the very high ultrafiltrability/diffusability of free morphine, only 1-3% of the total amount of infused morphine is removed in 24 h. This is in marked contrast to haemodialysis where, owing to much higher dialysate flow rate, a significant quantity of free morphine is removed.

Prognostic value of dipyridamole thallium-201 screening to minimize perioperative cardiac complications in diabetics undergoing kidney or kidney-pancreas transplantation

To minimize perioperative cardiac events, we utilize a screening protocol consisting of intravenous dipyridamole thallium-201 myocardial imaging (DPT), with the selective use of coronary angiography based on the presence of reversible defect(s) on DPT test. A retrospective study was performed to determine the prognostic value of this protocol and to identify any clinical parameters predictive of an abnormal DPT test. To accomplish this, a detailed chart analysis of 176 consecutive kidney (n = 89) and kidney-pancreas (n = 87) transplant recipients who had undergone pretransplant DPT testing was performed. The results of the DPT test were interpreted as normal in 111, fixed defect in 15, and reversible defect(s) in 50 patients. Forty-two of the 50 patients with reversible defect(s) underwent coronary angiography. Twelve of the 27 patients with significant coronary artery disease (CAD, > 50% stenosis in one or more coronary arteries) underwent pretransplant revascularization and the remaining 15 were treated medically. Cardiac events (documented acute myocardial infarction or sudden cardiac death) within 6 wk of transplant were stratified by the results of this protocol. Also, various clinical parameters were compared between patients with normal and abnormal (fixed and reversible defect) DPT tests. Only one of the 111 (0.9%) transplant recipients with a normal DPT test had a perioperative cardiac event. None of the 15 (0%) patients with a fixed defect and none of the 15 (0%) patients with reversible defect(s), but a nonsignificant (< 50% narrowing) coronary angiogram, had a perioperative cardiac event. Three of the 27 (11.1%) patients with reversible defect(s) and significant disease on coronary angiography, who had undergone pre-transplant revascularization or were managed medically, had a perioperative coronary event. Of 14 recipients parameters analyzed, age > 50 yr was the only variable predictive of an abnormal DPT test. We conclude that the incidence of perioperative cardiac events in patients with a normal or fixed defect, or reversible defect(s) but a nonsignificant (< 50% narrowing) coronary angiogram is very low, indicating the high correlation of these findings on DPT and an uneventful (cardiac) post-transplant course. The incidence of perioperative cardiac complications amongst the high-risk transplant recipients with reversible defect(s) and significant CAD on coronary angiogram may be minimized by appropriate preoperative medical management or revascularization. None of the clinical variables except age > 50 yr was predictive of an abnormal DPT test.