Favorable outcome of Fournier gangrene in two patients with diabetes mellitus on continuous peritoneal dialysis

Fournier gangrene (FG), a form of necrotizing fasciitis of the perineum and genitals, with high morbidity and mortality in the general population, carries the additional risk of involvement of the peritoneal catheter tunnel and peritoneal cavity in patients on chronic peritoneal dialysis (PD). We describe two men with diabetes who developed FG in the course of PD. Computed tomography showed no extension of FG to the abdominal wall, and spent peritoneal dialysate was clear in both patients. Broad-spectrum antibiotic therapy with anaerobic coverage and early aggressive debridement followed by negative-pressure wound therapy and repeated debridement led to improvements in clinical status in both cases. Surgical closure and healing of the wound was achieved in one patient; the wound of the second patient is healing, but remains open. Both patients experienced prolonged hospitalization, with a serious decline in nutrition status. In patients on PD, FG can be treated successfully. However, additional measures are required to evaluate for potential involvement of the PD apparatus and the peritoneal cavity in the infectious process; and prolonged hospitalization, worsening nutrition, and multiple surgical interventions can result.

Sustained remission of antineutrophil cytoplasmic antibody-mediated glomerulonephritis and nephrotic syndrome in mixed connective tissue disease

A woman diagnosed with mixed connective tissue disease (MCTD) developed an anti-myeloperoxidase (MPO) antineutrophil cytoplasmic antibody (ANCA) and nephrotic syndrome with normal serum creatinine. Percutaneous kidney biopsy showed pauci-immune glomerulonephritis with superimposed immune complex deposition. After treatment with cyclophophamide and prednisone, proteinuria decreased progressively to a level of 0.4 g/g creatinine, ANCA became undetectable, while serum creatinine remained normal seven years after the beginning of treatment. Sustained remission of nephrotic proteinuria with preserved renal function may follow treatment of ANCA-mediated disease developing in patients with MCTD.

Glomerular disease in patients with infectious processes developing antineutrophil cytoplasmic antibodies

To identify differences in treatment and outcome of various types of glomerulonephritis developing in the course of infections triggering antineutrophil cytoplasmic antibody (ANCA) formation, we analyzed published reports of 50 patients. Immunosuppressives were added to antibiotics in 22 of 23 patients with pauci-immune glomerulonephritis. Improvement was noted in 85% of 20 patients with information on outcomes. Death rate was 13%. Corticosteroids were added to antibiotics in about 50% of 19 patients with postinfectious glomerulonephritis. Improvement rate was 74%, and death rate was 26%. Two patients with mixed histological features were analyzed under both pauci-immune and post-infectious glomerulonephritis categories. In 9 patients with other renal histology, treatment consisted of antibiotics alone (7 patients), antibiotics plus immunosuppressives (1 patient), or immunosuppressives alone (1 patient). Improvement rate was 67%, permanent renal failure rate was 22%, and death rate was 11%. One patient with antiglomerular basement disease glomerulonephritis required maintenance hemodialysis. Glomerulonephritis developing in patients who became ANCA-positive during the course of an infection is associated with significant mortality. The histological type of the glomerulonephritis guides the choice of treatment. Pauci-immune glomerulonephritis is usually treated with addition of immunosuppressives to antibiotics.

Acidosis and coma in adult diabetic maintenance dialysis patients with extreme hyperglycemia

BACKGROUND

Extreme hyperglycemia (serum glucose ≥ 800 mg/dL or 44.4 mmol/L) is infrequently associated with impaired consciousness in patients on maintenance dialysis. The purpose of this study was to determine features of extreme hyperglycemia that bring about coma in dialysis patients who do not have any of the potential conditions, other than hyperglycemia, that can affect the sensorium.

METHODS

We analyzed 24 episodes of extreme dialysis-associated hyperglycemia in men who did not have neurological disease or sepsis. We compared serum parameters related to hyperglycemia between a group of 12 patients (8 on peritoneal dialysis, 4 on hemodialysis) who were alert and oriented (group A) and another group of 12 patients (5 on peritoneal dialysis, 7 on hemodialysis) who displayed varying degrees of impairment of sensorium, ranging from drowsiness to coma (group B).

RESULTS

Group B had, in the serum, lower total carbon dioxide (TCO2, 8 ± 4 vs. 20 ± 3 mmol/L, P < 0.01) and higher anion gap (AG, 32 ± 8 vs. 15 ± 4 mEq/L, P < 0.01) and potassium (6.3 ± 1.5 vs. 4.6 ± 1.0 mEq/L, P < 0.05) than group A. Serum levels of glucose, chloride, urea nitrogen, calculated osmolarity and tonicity did not differ between the two groups. The test for serum ketone bodies was positive only in group B (all patients). Stepwise multiple linear regression identified serum TCO2 and AG as the only predictors of impaired sensorium (r (2) = 0.74. P < 0.01).

CONCLUSION

There is a strong statistical association between the severity of diabetic ketoacidosis (DKA) and the level of impairment of consciousness in patients on dialysis with extreme hyperglycemia and no neurological or infectious disease. This association suggests that the presence or absence of DKA is usually the primary etiologic factor in the development of impaired sensorium in these patients.

The renal concentrating mechanism and the clinical consequences of its loss

The integrity of the renal concentrating mechanism is maintained by the anatomical and functional arrangements of the renal transport mechanisms for solute (sodium, potassium, urea, etc) and water and by the function of the regulatory hormone for renal concentration, vasopressin. The discovery of aquaporins (water channels) in the cell membranes of the renal tubular epithelial cells has elucidated the mechanisms of renal actions of vasopressin. Loss of the concentrating mechanism results in uncontrolled polyuria with low urine osmolality and, if the patient is unable to consume (appropriately) large volumes of water, hypernatremia with dire neurological consequences. Loss of concentrating mechanism can be the consequence of defective secretion of vasopressin from the posterior pituitary gland (congenital or acquired central diabetes insipidus) or poor response of the target organ to vasopressin (congenital or nephrogenic diabetes insipidus). The differentiation between the three major states producing polyuria with low urine osmolality (central diabetes insipidus, nephrogenic diabetes insipidus and primary polydipsia) is done by a standardized water deprivation test. Proper diagnosis is essential for the management, which differs between these three conditions.

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.

Symptomatic anti-neutrophil cytoplasmic antibody-positive disease complicating subacute bacterial endocarditis: to treat or not to treat?

A 54-year-old man was diagnosed with Streptococcus mutans endocarditis of the mitral valve. Serological tests disclosed the presence of multiple autoantibodies including c-ANCA, anti-PR3 and anti-MPO. While the fever subsided with antibiotics, mental status and renal function deteriorated rapidly. Kidney biopsy revealed pauci-immune glomerulonephritis and acute eosinophilic interstitial nephritis. The abnormal clinical features improved rapidly after addition of corticosteroids and cyclophosphamide to the antibiotics. Immunosuppressive agents may be required in a fraction of the patients with infective endocarditis who develop ANCA and ANCA-mediated renal disease. Histological identification of the type of renal disease is imperative for the choice of the treatment.

Hospital admissions in elderly patients on chronic hemodialysis

BACKGROUND

The purpose of this study was to determine whether number of hospital admissions per patient per year (n/[pt-yr]) and hospital days per patient per year (d/[pt-yr]) differ between elderly and younger patients on chronic hemodialysis (HD).

PATIENTS AND METHODS

In a retrospective cohort analysis of incident HD patients in one dialysis unit over 15 years, we compared 166 HD patients older than 70 years (77.1 ± 4.7 yrs) at the onset of HD (group A) and 216 patients younger than 70 years both at onset (57.1 ± 7.6 yrs) and at the end of the HD period (group B). Eighty (48.2%) of group A and 141 (65.3%) patients of group B had diabetes mellitus.

RESULTS

No differences were noted in the overall hospitalization rate, presented as mean, {95% Confidence interval} (group A 2.40 {2.04-2.75}, group B 2.03 {1.89-2.16} n[pt-yr]) and days/[pt-year] (group A 33.6 {25.3-41.8}, group B 24.1 {18.9-29.23}). Group A had higher number of hospitalization days (P = 0.012) for surgery or trauma and higher rate (P = 0.045) and days (P = 0.041) of hospitalization for miscellaneous causes, primarily pulmonary disease, or malignancy. Among diabetic patients, group A had only a greater number of hospital days for cardiac disease (P = 0.050). Among patients without diabetes, group A had a higher number for hospital days for surgery or trauma (P = 0.027). All other univariate comparisons were not significant. Multiple linear regression identified comorbidity, quantified by the Charlson index, Caucasian race and poor compliance with the HD schedule as predictors of admission rate and days per year for vascular access issues and comorbidity, poor compliance, and advanced age at onset of HD as predictors of admission for causes other than vascular access related.

CONCLUSION

Hospitalizations, which affect quality of life, differ little between elderly and younger patients on HD. Therefore, hospitalizations do not constitute an argument for restricting access to HD to elderly patients.

Activation of caspase-3 in the skeletal muscle during haemodialysis

BACKGROUND AND OBJECTIVE

Muscle atrophy in end-stage renal disease (ESRD) may be due to the activation of apoptotic and proteolytic pathways. We hypothesized that activation of caspase-3 in the skeletal muscle mediates apoptosis and proteolysis during haemodialysis (HD).

MATERIALS AND METHODS

Eight ESRD patients were studied before (pre-HD) and during HD and the findings were compared with those from six healthy volunteers. Protein kinetics was determined by primed constant infusion of L-(ring (13)C(6) ) Phenylalanine.

RESULTS

Caspase-3 activity in the skeletal muscle was higher in ESRD patients pre-HD than in controls (24966·0 ± 4023·9 vs. 15293·3 ± 2120·0 units, P<0·01) and increased further during HD (end-HD) (37666·6 ± 4208·3 units) (P<0·001). Actin fragments (14 kDa) generated by caspase-3 mediated cleavage of actomyosin was higher in the skeletal muscle pre-HD (68%) and during HD (164%) compared with controls. The abundance of ubiquitinized carboxy-terminal actin fragment was also significantly increased during HD. Skeletal muscle biopsies obtained at the end of HD exhibited augmented apoptosis, which was higher than that observed in pre-HD and control samples (P<0·001). IL-6 content in the soluble fraction of the muscle skeletal muscle was increased significantly during HD. Protein kinetic studies showed that catabolism was higher in ESRD patients during HD compared with pre-HD and control subjects. Muscle protein catabolism was positively associated with caspase-3 activity and skeletal muscle IL-6 content.

CONCLUSION

Muscle atrophy in ESRD may be due to IL-6 induced activation of caspase-3 resulting in apoptosis as well as muscle proteolysis during HD.

Abnormalities of serum potassium concentration in dialysis-associated hyperglycemia and their correction with insulin: review of published reports

The main difference between dialysis-associated hyperglycemia (DH) and diabetic ketoacidosis (DKA) or nonketotic hyperglycemia (NKH) occurring in patients with preserved renal function is the absence of osmotic diuresis in DH, which eliminates the need for large fluid and solute (including potassium) replacement. We analyzed published reports of serum potassium (K(+)) abnormalities and their treatment in DH. Hyperkalemia was often present at presentation of DH with higher frequency and severity than in hyperglycemic syndromes in patients with preserved renal function. The frequency and severity of hyperkalemia were higher in DH episodes with DKA than those with NKH in both hemodialysis and peritoneal dialysis. For DKA, the frequency and severity of hyperkalemia were similar in hemodialysis and peritoneal dialysis. For NKH, hyperkalemia was more severe and frequent in hemodialysis than in peritoneal dialysis. Insulin infusion corrected the hyperkalemia of DH in most cases. Additional measures for the management of hyperkalemia or modest potassium infusions for hypokalemia were needed in a few DH episodes. The predictors of the decrease in serum K(+) during treatment of DH with insulin included the starting serum K(+) level, the decreases in serum values of glucose concentration and tonicity, and the increase in serum total carbon dioxide level. DH represents a risk factor for hyperkalemia. Insulin infusion is the only treatment for hyperkalemia usually required.

Increased CD36 expression signals monocyte activation among patients with type 2 diabetes

OBJECTIVE

To explore the hypothesis that CD36, a scavenger receptor and fatty acid translocase, is upregulated in peripheral blood mononuclear cells (PBMCs) among patients with type 2 diabetes and is a biomarker of PBMC activation and inflammation.

RESEARCH DESIGN AND METHODS

We used a cross-sectional observational design to study a multi-racial/ethnic population sample consisting of Caucasians, Hispanics, and Native Americans with type 2 diabetes (n = 33) and nondiabetic control subjects (n = 27). PBMC CD36 mRNA/protein and plasma high sensitivity (hs) C-reactive protein (hsCRP), hs-interleukin-6 (hsIL-6), and adiponectin were measured.

RESULTS

Unadjusted PBMC CD36 mRNA and protein were 1.56- and 1.63-fold higher, respectively, among type 2 diabetic subjects versus control subjects. PBMC CD36 protein was directly associated with CD36 mRNA, plasma hsCRP, and hsIL-6 and inversely associated with plasma adiponectin in both groups.

CONCLUSIONS

Increased CD36 expression is a biomarker of PBMC activation and inflammation and may become a useful tool in cardiovascular disease risk stratification.

Imaging of peritoneal catheter tunnel infection using positron-emission tomography

Imaging by ultrasonography or scintigraphy may assist in the diagnosis and management of tunnel infections of the peritoneal dialysis (PD) catheter. Here, we report a case of tunnel infection in which imaging with positron-emission tomography (PET) correctly predicted failure of conservative management. A 61-year-old man with diabetic nephropathy commenced PD in January 2008. He developed erythema and drainage at the exit site, with negative cultures in February 2008, and frank exit-site infection (ESI) with purulent drainage growing methicillin-sensitive Staphylococcus aureus [MSSA (treated with 3 weeks of oral dicloxacillin)] in August 2008. Subsequently, MSSA-growing purulent drainage from the exit site persisted. Systemic antibiotics were not administered, but there was gradual improvement with gentamicin ointment alone. In November 2008, the patient developed partial extrusion of the outer cuff of the PD catheter. In January 2009, a new ESI developed. Despite a week of treatment with cefazolin and gentamicin, the patient still developed his first episode of peritonitis with coagulase-negative Staphylococcus. He then received intraperitoneal vancomycin with good response. Although the ESI appeared to have responded to the treatment, PET imaging showed increased fludeoxyglucose (FDG) activity in the whole abdominal wall portion of the PD catheter. The patient resisted removal of the catheter and had no further signs of infection until June 2009. At that time he presented with exuberant inflammatory tissue ("proud flesh") at the exit site. Repeated PET imaging again showed increased FDG activity along the abdominal wall portion of the catheter. The PD catheter was removed and found to be infected. The patient was placed on temporary hemodialysis. This case demonstrates that PET imaging, in addition to other imaging techniques, may be useful for diagnosing and managing PD catheter infections.

Sources of variation in estimates of lean body mass by creatinine kinetics and by methods based on body water or body mass index in patients on continuous peritoneal dialysis

OBJECTIVE

We identified factors that account for differences between lean body mass computed from creatinine kinetics (LBM(cr)) and from either body water (LBM(V)) or body mass index (LBM(BMI)) in patients on continuous peritoneal dialysis (CPD).

DESIGN

We compared the LBM(cr) and LBM(V) or LBM(BMI) in hypothetical subjects and actual CPD patients.

PATIENTS

We studied 439 CPD patients in Albuquerque, Pittsburgh, and Toronto, with 925 clearance studies.

INTERVENTION

Creatinine production was estimated using formulas derived in CPD patients. Body water (V) was estimated from anthropometric formulas. We calculated LBM(BMI) from a formula that estimates body composition based on body mass index. In hypothetical subjects, LBM values were calculated by varying the determinants of body composition (gender, diabetic status, age, weight, and height) one at a time, while the other determinants were kept constant. In actual CPD patients, multiple linear regression and logistic regression were used to identify factors associated with differences in the estimates of LBM (LBM(cr)<LBM(V), or LBM(cr)<LBM(BMI)).

MAIN OUTCOME MEASURE

We sought predictors of the differences LBM(V) - LBM(cr) and LBM(BMI) - LBM(cr).

RESULTS

Both LBM(V) (regardless of formula used to estimate V) and LBM(BMI) exceeded LBM(cr) in hypothetical subjects with average body compositions. The sources of differences between LBM estimates in this group involved differences in the coefficients assigned to gender, age, height, weight, presence or absence of diabetes, and serum creatinine concentration. In CPD patients, mean LBM(V) or LBM(BMI) exceeded mean LBM(cr) by 6.2 to 6.9 kg. For example, the LBM(V) obtained from one anthropometric formula was 50.4+/-10.4 kg and the LBM(cr) was 44.1+/-13.6 kg (P < .001), whereas among the 925 clearance studies, only 216 (23.3%) had LBM(cr)>LBM(V). The differences in determinants of body composition between groups with high versus low LBM(cr) were similar in hypothetical and actual CPD patients. Multivariate analysis in actual CPD patients identified serum creatinine, height, age, gender, weight, and body mass index as predictors of the differences LBM(V)-LBM(cr) and LBM(BMI)-LBM(cr).

CONCLUSIONS

Overhydration is not the sole factor accounting for the differences between LBM(cr) and either LBM(V) or LBM(BMI) in CPD patients. These differences also stem from the coefficients assigned to major determinants of body composition by the formulas estimating LBM.

Spontaneous erythrocytosis in a patient on chronic hemodialysis

While anemia is common in patients on chronic hemodialysis (HD), spontaneous erythrocytosis is rare and can be caused by either the same conditions causing erythrocytosis in the general population or any condition specific to chronic renal failure. We present a patient illustrating this latter circumstance. A 53-year-old man with diabetic nephropathy, with no known disease causing hypoxemia started HD in April 2001. Blood hemoglobin (Hgb) level was 13.7 +/- 2.8 g/dL while his kidney function was normal (1993-1996) and after 1997, with the development of chronic kidney disease, decreased progressively to a low of 10.2 g/dL in March 2001 when erythropoietin (EPO) injections were started. Erythropoietin requirements progressively decreased because of rising Hgb. Erythropoietin was discontinued in mid-2005. Blood hemoglobin continued to rise, however, to a high value of 17.6 g/dL in February 2006. At the same time, endogenous blood EPO level was 3.6 mIU/mL, a value consistent with primary polycythemia. White blood cell and platelet counts were normal. Several small renal cysts, including 1 complex cyst, were detected by ultrasonography and computer tomography in April 2006. He refused surgical treatment. He was treated with small phlebotomies (not returning the blood in the dialyzer at the end of dialysis) and monitoring of Hgb, which decreased toward the desired range. Repeated computer tomographic scans showed a slow increase in the size of the complex cyst and several other cysts. In late 2007 Hgb started rising again, and in February 2008, while the Hgb level was 16.4 g/dL, the endogenous serum EPO level was 726 mIU/mL (upper normal limit 31.5 mIU/mL). Intermittent phlebotomies were reinstituted. He subsequently developed multiple vascular catastrophes and expired from ischemic bowel disease in September 2008. Acquired cystic disease of the kidneys should be considered in HD patients who develop spontaneous erythrocytosis. The risks of acquired cystic disease include, in addition to the development of malignancy, vascular events from elevated Hgb.

Anemia management and association of race with mortality and hospitalization in a large not-for-profit dialysis organization

BACKGROUND

The optimal hemoglobin target and possible toxicity of epoetin therapy in hemodialysis patients are controversial. Previous studies suggest that African American patients use higher doses of epoetin and have better survival compared with white hemodialysis patients.

STUDY DESIGN

Retrospective longitudinal cohort.

SETTING & PARTICIPANTS

Epoetin-exposed incident hemodialysis patients (N = 12,733; African Americans, n = 4,801; white, n = 7,386) treated in Dialysis Clinic Inc facilities during 2000 to 2006.

PREDICTORS

Hemoglobin, epoetin, iron.

OUTCOMES

Mortality, hospitalization.

MEASUREMENTS

Proportional hazards models with time-varying covariates.

RESULTS

Hemoglobin concentrations less than 10 g/dL in whites and less than 11 g/dL in African Americans were associated with increased mortality and hospitalization versus the referent hemoglobin level of 11 to 11.9 g/dL. Hemoglobin levels of 13 g/dL or greater in whites were associated with decreased noncardiovascular mortality. Six-month cumulative epoetin doses of 20,000 U/wk or greater were associated with increased mortality and hospitalization versus the referent group (8,000 to 12,499 U/wk). Epoetin doses less than 8,000 U/wk were associated with decreased risk. Higher epoetin doses were associated with increased mortality at hemoglobin concentrations of 10 to 12.9 g/dL and with increased hospitalization at all hemoglobin concentrations of 10 g/dL or greater. Higher epoetin doses were associated with increased mortality and hospitalization within each tertile of serum albumin concentration. These patterns did not differ by race.

LIMITATIONS

Treatment-by-indication bias and unidentified confounders cannot be excluded. Small sample sizes in the highest and lowest hemoglobin strata decrease statistical power.

CONCLUSIONS

Relationships between hemoglobin concentration and mortality differed between African Americans and whites. Additionally, the relationship of lower mortality with greater achieved hemoglobin concentration seen in white patients was observed for all-cause, but not cardiovascular, mortality. A higher cumulative epoetin dose was associated with worse outcomes, even in patients with albumin levels greater than 4 g/dL. There were no statistically significant interactions between race and epoetin dose. Further studies are needed to confirm and to define the mechanism of these findings.

Pathophysiology and management of fluid and electrolyte disturbances in patients on chronic dialysis with severe hyperglycemia

The mechanisms of fluid and solute abnormalities that should be considered in any patient with severe hyperglycemia include changes in the total amount of extracellular solute, osmotic diuresis, intake of water driven by thirst, and influences from associated conditions. The absence of osmotic diuresis distinguishes dialysis-associated hyperglycemia (DH) from hyperglycemia with preserved renal function (HPRF). Mainly because of this absence, comparable degrees of hyperglycemia tend to produce less hypertonicity and less severe intracellular volume contraction in DH than in HPRF, while extracellular volume is expanded in DH but contracted in HPRF. Ketoacidosis can develop in both DH and HPRF. Among DH patients, hyperkalemia appears to be more frequent when ketoacidosis is present than when nonketotic hyperglycemia is present. Among HPRF patients, the frequency of hyperkalemia appears to be similar whether ketoacidosis or nonketotic hyperglycemia is present. Usually patients with severe DH have no symptoms or may exhibit a thirst. Infrequent clinical manifestations of DH include coma and seizures from hypertonicity or ketoacidosis and pulmonary edema from extracellular expansion. Insulin infusion is usually the only treatment required to correct the biochemical abnormalities and reverse the clinical manifestations of DH. Monitoring of the clinical manifestations and biochemical parameters during treatment of DH with insulin is needed to determine whether additional measures, such as administration of saline, free water, or potassium salts, as well as emergency hemodialysis (HD) are needed. Emergency HD carries the risk of excessively rapid decline in tonicity; its benefits in the treatment of DH have not been established.