KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Glomerular Diseases.

The KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases represents the first update to this set of recommendations since the initial set of KDIGO guideline recommendations was published in 2012. The pace of growth in our molecular understanding of glomerular disease has quickened and a number of newer immunosuppressive and targeted therapies have been introduced since the original set of guideline recommendations, making such an update necessary. Despite these updates, many areas of controversy remain. In addition, further updates since the publication of KDIGO 2021 have occurred which this guideline does not encompass. With this commentary, the KDOQI work group has generated a chapter-by-chapter companion opinion article that provides commentary specific to the implementation of the KDIGO 2021 guideline in the United States.

The lupus nephritis classification: lost in translation.

PURPOSE OF REVIEW: The ISN/RPS lupus nephritis classification is in the process of undergoing a revision. It has lost its way and morphed from a classification based on pathophysiology of disease into a staging system based on the extent of spread and prognosis. RECENT FINDINGS: There are multiple different pathophysiologic processes that contribute to lupus nephritis. The current classification is inadequate, as it does not highlight these differences and thus squanders the opportunity to develop targeted therapies. Its focus is on the extent of disease as opposed to the pattern of injury, which defines the disease. To delineate the cause, we must include immunofluorescent and electron microscopy, which will help define the pattern of injury. SUMMARY: To determine eventual targeted treatments for lupus nephritis, we must first classify the disease according to the available pathophysiologic mechanisms. In the upcoming revision, including the immunofluorescence and electron microscopy and eliminating the overemphasis on extent of disease are the first steps to categorizing the lupus nephritis classes accurately.

IgA Nephropathy with Crescents: A Single-Center Experience.

INTRODUCTION: The presence of crescents in IgA nephropathy (IgAN) has been associated with a poor prognosis. We assess the prognosis of crescents in our patients with IgAN. METHODS: IgAN was diagnosed in 73 patients biopsied at Rush University Medical Center from 1992 to 2020, and crescents were seen in 26 (36%). Clinical, laboratory and histologic features at biopsy, and treatment and outcome (end-stage kidney disease, ESKD) were collected retrospectively. Data are presented as mean ± SD and a p value of <0.05 was significant. RESULTS: There was no difference in hypertension, SCr, or eGFR in patients with crescents compared to those without crescents but patients with crescents had higher UPro/Cr ratio (2.8 ± 2.7 vs. 1.7 ± 1.7 g/g, p 0.04). The percentage of glomeruli with global and segmental sclerosis (32 ± 25% vs. 38 ± 28%, p 0.35) and the proportion of interstitial fibrosis and tubular atrophy (22 ± 20% vs. 22 ± 22%, p 0.76) were similar. Only 19% of patients with crescents had lesions involving ≥25% of glomeruli. A larger proportion of patients with crescents were treated with immunosuppressive agents (70% vs. 21%, p 0.0005). After 8.4 ± 7 years of follow-up, ESKD (19% vs. 23%, p 0.77) and renal survival at 10 years (80% vs. 74%, p 0.99) were similar in patients with and without crescents. CONCLUSION: The presence of crescents in IgAN was not associated with an increased risk of progression to ESKD. This may be a result of the fact that the majority of our patients had crescents involving <25% of glomeruli and received aggressive treatment with immunosuppressive agents.

Bisphosphonate Versus Bisphosphonate and Calcitonin for the Treatment of Moderate to Severe Hypercalcemia of Malignancy.

BACKGROUND: Historically, intravenous (IV) bisphosphonates with calcitonin are the treatment of choice for hypercalcemia of malignancy. However, evidence is lacking. OBJECTIVE: The objective of this study was to compare the use of bisphosphonate versus bisphosphonate with calcitonin for moderate to severe hypercalcemia of malignancy. METHODS: This was a retrospective study evaluating patients who received bisphosphonate and/or calcitonin for treatment of moderate to severe hypercalcemia of malignancy. Patients received usual care plus either (1) bisphosphonate or (2) bisphosphonate with calcitonin. The primary outcome was change in corrected serum calcium concentrations 48 hours after treatment. Secondary outcomes included corrected calcium levels, incidence of normocalcemia and hypocalcemia, time to normocalcemia, hospital length of stay, and cost avoidance. RESULTS: The 48-hour decrease in corrected calcium was less in the bisphosphonate group than in the combination group (2.4 [1.6-3.4] vs 3.9 [3.5-5.3]; P < 0.001). However, initial calcium levels in the combination group were higher than in the bisphosphonate group, and calcium levels at 24, 48, and 72 hours were similar. Secondary outcomes did not differ. Average cost avoidance with bisphosphonate monotherapy was $11 248 per patient and $291 448 per year. CONCLUSIONS AND RELEVANCE: In the treatment of moderate to severe hypercalcemia of malignancy, IV bisphosphonate in combination with calcitonin resulted in a higher difference in corrected calcium levels at 48 hours compared with bisphosphonate therapy alone. However, corrected calcium levels in the first 72 hours, time to normocalcemia, and clinical outcomes were similar. The addition of calcitonin increases cost without substantial clinical benefit, and providers may consider avoiding calcitonin.

Percutaneous Renal Biopsy Using an 18-Gauge Automated Needle Is Not Optimal.

BACKGROUND: As percutaneous renal biopsies (PRBs) are increasingly performed by radiologists, an increase in the use of 18-gauge automated needle stands to compromise adequacy. We compare the adequacy and safety of PRB with 14-, 16-, and 18-gauge automated needles. METHODS: PRB of native (N-592) and transplant (T-1,023) kidneys was performed from January 2002 to December 2019 using real-time ultrasound. Baseline clinical and laboratory data, biopsy data (number of cores, total glomeruli, and total glomeruli per core), and outcome (hematoma on renal US at 1-h, complications, and transfusion) were collected prospectively. PRB with N14g (337) versus N16g (255) and T16g (892) versus T18g (131) needles were compared. A p value of <0.05 was significant. RESULTS: PRB with an 18-g needle yielded the lowest number of total glomeruli per biopsy (N14g vs. N16g: 33 ± 13 vs. 29 ± 12, p < 0.01 and T16g vs. T18g: 34 ± 16 vs. 21 ± 11, p < 0.0001), significantly fewer total glomeruli per core (T16g vs. T18g: 12.7 ± 6.4 vs. 9.6 ± 5.0, p < 0.001 and N16g vs. T18g: 14.2 ± 6.3 vs. 9.6 ± 5.0, p < 0.001). A hematoma by renal US 1-h post-PRB was similar for native (14g-35% vs. 16g-29%, p = 0.2), and transplant biopsies (16g-10% vs. 18g-9%, p = 0.9) and the complication rate for native (14g-8.9% vs. 16g-7.1%, p = 0.5), transplant biopsies (16g-4.6% vs. 18g-1.5%, p = 0.2) and transfusion rate for native (14g-7.7% vs. 16g-5.8%, p = 0.4), and transplant biopsies (16g-3.8% vs. 18g-0.8%, p = 0.1) were similar irrespective of needle size. CONCLUSIONS: PRB of native and transplant kidneys with the use of a 16-gauge needle provides an optimal sample. However, our experience in transplant biopsies suggests the use of an 18-gauge needle stands to jeopardize the diagnostic accuracy of the PRB while not improving safety.

Single-dose sodium polystyrene sulfonate for hyperkalemia in chronic kidney disease or end-stage renal disease.

BACKGROUND: The use of sodium polystyrene sulfonate (SPS) for the treatment of hyperkalemia lacks sufficient efficacy data in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD); however, use remains widespread. Recent evidence suggests that this population may be at risk for serious gastrointestinal adverse effects with SPS. Methods. We conducted a single-center retrospective cohort study. Adult patients with CKD Stages 4, 5, or ESRD maintained on renal replacement therapy with serum potassium >5 mEq/L and receipt of SPS were screened for inclusion. Our primary outcome was decrease in potassium within 24 h post-30 g oral SPS suspended in 33% sorbitol. Secondary outcomes included decrease in potassium within 24 h from 15 or 30 g SPS doses and gastrointestinal adverse events. RESULTS: Of 596 records, 114 were included for analysis. At the first serum potassium level within 24 h post-30 g oral SPS the median potassium decrease was 0.8 mEq/L [interquartile range (IQR) 0.4-1.1; P < 0.001]. At the first potassium level within 24 h post-15 or 30 g SPS, the median potassium decrease was 0.7 mEq/L (IQR 0.4-1.0; P < 0.001]. Post-SPS potassium levels occurred 14-16 h post-SPS. Gastrointestinal side effects occurred within 30 days of SPS in 5% of patients, although only two cases were classified as possibly associated. CONCLUSIONS: The use of single-dose SPS monotherapy resulted in a significant decrease in serum potassium levels within 24 h in patients with CKD Stage 4, 5, or ESRD. However, it remains unclear if SPS is associated with an increased risk of gastrointestinal injury in this population.

Risk of percutaneous renal biopsy of native kidneys in the evaluation of acute kidney injury.

BACKGROUND: Percutaneous renal biopsy (PRB) of native kidneys (NKs) to better understand and treat acute kidney injury (AKI) is being advocated, but little is known about the risk of complications. METHODS: We performed a retrospective study of PRB of NKs in 955 adults from 1991 to 2015 at an academic medical center with real-time ultrasound and automated biopsy needles. Patients undergoing PRB for evaluation of AKI (n = 160) were compared with 795 patients biopsied for other reasons (not-AKI) for postbiopsy complications [need for transfusion of packed red blood cells (PRBCs), an interventional radiologic or surgical procedure, readmission or death]. RESULTS: Patients biopsied for AKI were older (58 ± 16 versus 44 ± 16 years; P < 0.0001), with a higher serum creatinine (SCr) (4.5 ± 2.7 versus 1.8 ± 1.6 mg/dL; P < 0.0001) and lower hemoglobin (Hgb) (10.4 ± 1.7 versus 12.1 ± 2.1; P < 0.0001) and a greater proportion had an abnormal bleeding time (12.5% versus 7.4%, P 0.04), partial thromboplastin time (15.2% versus 5.3%, P < 0.0001) and/or prothrombin time (27.0% versus 12.8%; P < 0.0001) compared with not-AKI patients. Complications post-PRB were significantly greater in patients biopsied for AKI {11.3% versus 6.7%; P=0.04; odds ratio [OR] 1.78 [95% confidence interval (CI) 1.01-3.12]} with patients biopsied for AKI requiring more blood transfusions (10.0% versus 5.3%; P 0.02; OR 2.04 (95% CI 1.12-3.74)]. By multivariate analysis, baseline features predictive of a complication were increased SCr and decreased Hgb level, as well as female gender and increased systolic blood pressure. CONCLUSION: Patients biopsied for evaluation of AKI are at greater risk of complications due to increased risk factors.

Comparison of native and transplant kidney biopsies: diagnostic yield and complications.

BACKGROUND: The safety and adequacy are established for the native percutaneous renal biopsy (PRB) but no prospective studies exist that directly compare these with transplant PRB. METHODS: From 1995 to 2015, 1705 adults underwent percutaneous native [native renal biopsy (NRB)] or transplant renal biopsy (TRB) by the Nephrology service. Real-time ultrasound and automated biopsy needles (NRB, 14 or 16 gauge; TRB, 16 gauge) were used. Patients were observed for 24 h (NRB) or 8 h (TRB) post-procedure. Adequacy was defined as tissue required for diagnosis plus glomerular yield. Complications were defined as those resulting in the need for an intervention, such as surgery, interventional radiologic procedure, readmission, blood transfusion and death. Data were collected prospectively in all biopsies. RESULTS: At the time of biopsy, NRB patients were younger (mean ± SD, 47 ± 17 versus 50 ± 14 years, P < 0.0001) and more often female (62 versus 48%, P < 0.0001) compared with TRB. A fellow supervised by an attending performed the procedure in 91% of NRB compared with 63% of TRB (P < 0.0001). TRB patients were more hypertensive [systolic blood pressure (SBP) 140 ± 22 versus 133 ± 18 mmHg, P < 0.0001] and had a higher serum creatinine (3.1 ± 1.8 versus 2.3 ± 2.2 mg/dL, P < 0.0001), activated partial thromboplastin time (28 ± 4.3 versus 27 ± 5 s, P < 0.0001) as well as lower hemoglobin (Hgb) (11.2 ± 1.8 versus 11.7 ± 2.1 g/dL, P < 0.0001) compared with NRB. Adequate tissue for diagnosis was obtained in > 99% of NRB and TRB (P = 0.71). Compared with TRB, NRB had a greater drop in Hgb after the biopsy (0.97 ± 1.1 versus 0.73 ± 1.3 g/dL, P < 0.0001), a higher complication rate (6.5 versus 3.9%, P = 0.02) and higher transfusion rate (5.2 versus 3.3%, P = 0.045). There was one death in each group attributed to the biopsy. CONCLUSIONS: Although death is equally rare, the complication rate is higher in NRB compared with TRB despite TRB having more of the traditional risk factors for bleeding. Differences in technique, operator (fellow or attending) or needle gauge may explain this variability.

Changing Trends in the Performance of Percutaneous Renal Biopsy from Nephrologist to Interventional Radiologist: A Single-Center Experience.

BACKGROUND: Percutaneous renal biopsy of native kidneys (PRB) has been an integral part of the practice of nephrology. However, over the past 30 years, PRB has transitioned from a procedure performed only by nephrologists to interventional radiologists (IRs). We surveyed practicing nephrologists completing training in our program to determine the clinical practice patterns of PRB. METHODS: The 78 fellows completing the nephrology program at Rush University Medical Center from June 1984 through June 2017 were successfully contacted and surveyed regarding their opinion on adequacy of their training and whether they performed PRB in practice and if not or no longer, why. To evaluate for differences in the performance of PRB over time, a comparison of 4 periods of fellowship completion (i.e., 1984-1990, 1991-2000, 2001-2010, 2011-2017) was performed. RESULTS: All 78 nephrologists felt they had been adequately trained to perform PRB. PRB was performed by 45 (58%) nephrologists post-fellowship, but a significant decline was observed over the 4 periods of time from 1984 to 2017 (100 vs. 86 vs. 52 vs. 20%, p < 0.0001). The primary reason that 33 nephrologists did not perform PRB was that it was too time consuming and IR was available to perform PRB. Of the 71 nephrologists still in practice only 12 (17%) continue to perform PRB. A greater proportion of nephrologists completing training from 1984-1990 continue to perform PRB relative to those trained after 1990. The universal reason that nephrologists were no longer performing PRB was again an issue of time and the fact that IRs were available to perform PRB. CONCLUSION: We find that there has been a significant transition over time in the performance of PRB by a nephrologist to IR. The major reason for this is the time burden associated with PRB and the availability of IRs.

McArdle disease: a "pediatric" disorder presenting in an adult with acute kidney injury.

Rhabdomyolysis is characterized by the acute breakdown of skeletal muscle, resulting in the release of muscle cell contents, subsequent myoglobinuria, and in severe cases, acute renal failure. A number of etiologies have been identified in acute rhabdomyolysis, in which drugs and trauma account for the majority of cases. One etiological category that is commonly overlooked in the adult population is an underlying genetic defect. This may be challenging to diagnose due to its rarity in the adult demographic and the marked heterogeneity, often requiring a high level of clinical suspicion before investigation is pursued. Once diagnosed, however, appropriate steps can be taken to reduce future episodes of rhabdomyolysis, further renal injury, and other systemic complications. Here, we report a case of an adult patient presenting with acute rhabdomyolysis secondary to McArdle disease, a genetic disease causing defective glycogenolysis. The case highlights the importance of recognizing the potential of undiagnosed "pediatric" disorders in adulthood and particularly for underlying genetic causes of rhabdomyolysis.

Reset Osmostat: The Result of Chronic Desmopressin Abuse?

A reset osmostat as a cause of hyponatremia can be found in a variety of clinical settings, including pulmonary and neurologic diseases, as well as in physiologic circumstances such as pregnancy. This teaching case describes a 72-year-old white man with a long-standing history of self-medicating with desmopressin acetate (DDAVP) who presented with profound hyponatremia. On discontinuation of DDAVP treatment, he was found to have a reset osmostat. The mild hyponatremia persisted on follow-up. We theorize that the reset osmostat may have developed secondary to long-standing DDAVP use.

The Impact of Baseline Serum Creatinine on Complete Remission Rate and Long-Term Outcome in Patients with Severe Lupus Nephritis.

BACKGROUND/AIM: We assess the impact of serum creatinine at baseline on complete remission rate and long-term outcome in severe lupus nephritis (SLN). METHODS: A total of 86 adult patients with SLN [International Society of Nephrology/Renal Pathology Society (ISN/RPS) class IV lesions] were evaluated based on baseline serum creatinine levels (≤1.0, 1.01-1.5, 1.51-2.0, 2.01-3.0, and >3.0 mg/dl; n = 22, 23, 16, 12, and 13, respectively). The complete remission rates (serum creatinine level of ≤1.4 mg/dl and proteinuria of ≤0.33 g/day) and long-term outcomes (stable renal function, dialysis, and death) were compared. The patients were followed for 121 ± 64 months. RESULTS: The baseline clinical features were similar, but the chronicity index was significantly higher with increasing levels of serum creatinine. Complete remission rates were significantly higher in patients with lower levels of serum creatinine (86 vs. 52 vs. 19 vs. 25 vs. 0%, p < 0.0001). Patients with a baseline serum creatinine level of ≤1.0 mg/dl were >16 times as likely (OR 16.2; 95% CI: 4.2-61.5) to attain a complete remission and >6 times as likely (OR 6.1; 95% CI: 1.9-18.6) to have stable renal function at the last follow-up as compared to patients with a serum creatinine level of >1.0 mg/dl. The 15-year renal survival rate was greatest among those patients with a baseline serum creatinine level of ≤1.0 mg/dl (76 vs. 57 vs. 48 vs. 25 vs. 10%, p < 0.0001). CONCLUSION: The prognosis of SLN is significantly affected by the serum creatinine level at baseline. The complete remission rate is highest, and the long-term prognosis most favorable, in patients with a baseline serum creatinine level of ≤1.0 mg/dl. This emphasizes the importance of early diagnosis and treatment.

We Perform Surveillance for Arteriovenous Graft Stenosis.

Successful hemodialysis is dependent on high unimpeded blood flow. Arteriovenous grafts are notorious for access stenosis, a precursor for access thrombosis. Access surveillance techniques are available and in observational studies have been superior to clinical monitoring for the detection of access stenosis and subsequent prevention of thrombosis in arteriovenous grafts. However, in prospective randomized controlled studies, these surveillance techniques have not been superior to clinical monitoring in reducing access thrombosis and or prolonging access survival. Presently, routine surveillance should not be performed until it can be proven to be effective at prolonging thrombosis free graft survival.

Clinical factors influencing the decision to transfuse after percutaneous native kidney biopsy.

BACKGROUND: Transfusion of erythrocytes is the most common intervention after a complicated percutaneous renal biopsy (PRB). Anemia is considered to be a leading risk factor for bleeding following a PRB, and based on recent studies of transfusions in hospitalized patients, many institutions are restricting the threshold for erythrocyte transfusion to a lower hemoglobin concentration (Hgb). The purpose of this study is to analyze factors that influence the transfusion decision after a PRB, and to determine whether anemia is truly a risk factor for bleeding or anemic patients are simply more likely to receive a transfusion because of their already lower pre-PRB Hgb. METHODS: PRB of native kidneys was performed using real-time ultrasound with automated biopsy needles from January 1990 to April 2014. All patients were prospectively followed for bleeding with a 24-h inpatient observation. An intervention for a bleeding complication (BL-I) was defined by undergoing a procedure (cystoscopy, embolization), receiving a blood transfusion (BL-T), death and/or readmission related to the biopsy. To further define the effect of anemia, patients were divided into three pre-PRB Hgb groups: <9.0 g/dL (n = 79), 9.0-11.0 g/dL (n = 266) and >11.0 g/dL (n = 565). RESULTS: BL-I occurred in 71/910 (7.8%) of PRBs. The majority of these were BL-T (57/71, 80%; 57/910, 6.3% overall). Patients with BL-I had lower pre-PRB Hgb than those without BL-I (mean ± SD; 10.3 ± 2.0 versus 12.0 ± 2.1 g/dL, P < 0.0001) and a greater change (Δ) in Hgb (2.1 ± 1.6 versus 1.0 ± 0.8 g/dL, P < 0.0001). When compared with higher Hgb, patients with Hgb <9.0 g/dL had more traditional risk factors for bleeding (older age: 49 ± 18 versus 48 ± 18 versus 45 ± 16 years, P = 0.02; female: 72 versus 70 versus 56%, P < 0.0001; higher serum creatinine: 4.0 ± 2.9 versus 2.9 ± 2.6 versus 1.7 ± 1.4 mg/dL, P < 0.0001; higher systolic blood pressure: 138 ± 18 versus 133 ± 19 versus 133 ± 18 mmHg, P = 0.06; higher bleeding time: 7.6 ± 1.8 versus 7.4 ± 2.0 versus 6.7 ± 1.8 min, P < 0.0001). When BL-T was stratified by pre-PRB Hgb, there were more transfusions in those with lower pre-PRB Hgb (24 versus 9 versus 3%, P < 0.0001). However, these patients not only had fewer hematomas (58 versus 83 versus 87%, P = 0.04) but also demonstrated a smaller ΔHgb post-PRB (1.3 ± 1.0 versus 1.8 ± 0.8 versus 3.2 ± 1.6, P < 0.0001) compared with patients with higher pre-PRB Hgb, yet still received a transfusion. CONCLUSIONS: While patients with lower pre-PRB Hgb have more of the traditional risk factors for a complication after PRB, there was actually less clinically evident bleeding in these patients who were transfused. Although anemia itself has been considered to be a risk factor for a complication in the past, it more accurately represents only a predictor of receiving an erythrocyte transfusion. In the setting of the PRB, the decision for transfusion is influenced more by the severity of anemia at baseline as opposed to clinically evident bleeding.

Adequacy and complication rates with 14- vs. 16-gauge automated needles in percutaneous renal biopsy of native kidneys.

In performing percutaneous renal biopsy (PRB) of native kidneys, an increasing use of 16-gauge automated biopsy needles has been observed. We compare the adequacy and safety of PRBs in adults performed with a 14-gauge (n = 82) vs. 16-gauge (n = 55) automated needle using real-time ultrasound (US) from 1/2010 to 12/2013. Baseline clinical and laboratory data along with outcome data (renal US 1-hour postbiopsy, biopsy adequacy, and safety) were collected prospectively. There was no difference in age, gender, blood pressure, serum creatinine, or pre-PRB hemoglobin at baseline for PRBs performed with a 14- vs. 16-gauge needle. The number of glomeruli obtained per biopsy was similar (29 ± 11 vs. 31 ± 14, p = 0.6) and adequate tissue for diagnosis was obtained in 99% and 100% of biopsies. The clinical complication (8.5% vs. 9.1%, p = 1.0), transfusion (7.3% vs. 7.2%, p = 1.0), and embolization (3.7% vs. 1.8%, p = 0.6) rates were not significantly different for 14- vs. 16-gauge needles, but by routine renal US 1-hour post-PRB, a perinephric hematoma was demonstrated more often in biopsies done with the 14-gauge needle (39% vs. 22%, P 0.04). Thus, while the success of PRB of native kidneys is similar for both needle gauges, the potential for complication may be less using a 16-gauge automated needle.

Percutaneous renal biopsy of native kidneys: a single-center experience of 1,055 biopsies.

BACKGROUND: Percutaneous renal biopsy (PRB) of native kidneys is an essential tool in the diagnosis and management of renal disease. We report one of the largest single-center experiences on the success and safety of the procedure. METHODS: From June 1983 to March 2012, 1,055 adults underwent PRB using real-time ultrasound guidance and 14-gauge biopsy needles. Data were collected prospectively for 826 biopsies (78%). Statistical analysis was performed using the Mann-Whitney test, Wilcoxon matched pairs test and Kruskal-Wallis test for continuous data or the Fisher's exact test and χ(2) test for categorical data. Multivariate analysis using logistic regression was performed to determine which feature at baseline was predictive of a complication following renal biopsy. RESULTS: Patients were aged 46 ± 17 years; 38% were male, 40% were white and 43% were African-American. Serum creatinine (SCr) was 2.3 ± 2.3 mg/dl (>1.5 mg/dl in 47%). The pre-PRB hemoglobin was 12 ± 2 g/dl (<11.0 g/dl in 35%). Adequate tissue for diagnosis was obtained in 99% of biopsies. Minor complications occurred in 8.1% of biopsies (mainly gross hematuria, in 4.5%). Major complications occurred in 6.6% of biopsies, with transfusions required in 5.3%. Only 1 death (0.09%) resulted from post-PRB bleeding. By multivariate analysis, baseline features predictive of a complication were systolic blood pressure >170 mm Hg (OR 4.2, 95% CI 1.8-9.8), bleeding time >7.5 min (OR 1.7, CI 1.2-2.5) and SCr >3.5 mg/dl (OR 1.8, CI 1.2-2.9). CONCLUSIONS: PRB of native kidneys using real-time ultrasound with a 14-gauge automated needle remains a successful and safe procedure.

Complications of the percutaneous kidney biopsy.

Percutaneous kidney biopsy is an integral part of a nephrologist's practice. It has helped to define nephrology as a subspecialty. When indicated, it is a necessary procedure to help patients, as it allows for diagnostic, prognostic, and therapeutic information. Although very safe, this procedure can give rise to complications, mainly related to bleeding. Since its development in the 1950s, modifications have been made to the approach and the technique, which have improved the diagnostic yield while keeping it a safe procedure. Alterations to the standard approach may be necessary if risk factors for bleeding are present. In addition, obesity, pregnancy, and solitary kidney biopsy are all special circumstances that change the procedure itself or the risk of the procedure. Today, kidney biopsy is a vital procedure for the nephrologist: clinically relevant, safe, and effective.

Does regular surveillance improve the long-term survival of arteriovenous fistulas?

The rate of arteriovenous fistula (AVF) placement continues to rise and AVF failure is a major complication. The main cause of AVF failure is stenosis leading to thrombosis. Although the detection of early stenosis with preemptive correction prior to thrombosis seems to be a plausible option to prevent access failure, there is much debate, on the basis of studies of surveillance with arteriovenous grafts, as to whether early surveillance actually improves the longevity of AVFs. Evaluating the available information for surveillance, specifically the data for AVF stenosis and survival, is necessary to determine if surveillance is warranted. These trials have shown that vascular access flow (Qa) surveillance is beneficial in revealing subclinical stenosis. Preemptive angioplasty and surgical revision have shown to decrease thrombosis rates. However, at the present time, there is only limited data on whether preemptive treatment equates to improved long-term AVF survival.