Darren Schmidt

Volume-related weight gain and subsequent mortality in acute renal failure patients treated with continuous renal replacement therapy.

Fluid overload is a frequent finding in critically ill patients suffering from acute kidney injury (AKI). To assess the impact of fluid overload on the mortality of AKI patients treated with continuous renal replacement therapy (CRRT), we used a registry of 81 critically ill patients with AKI initiated on CRRT assembled over an 18-month period to conduct a cross- sectional analysis using volume-related weight gain (VRWG) of ≥10% and ≥20% of body weight and oliguria (≤20 ml/h) as the principal variables, with the primary outcome measure being mortality at 30 days. Mean Apache II scores were 27.5 ± 6.9 with overall cohort mortality of 50.6%. Mean (±SD) VRWG was 8.3 ± 9.6 kg, representing a 10.2% ± 13.5% increase since admission. Oliguria was present in 65.4% of patients. Odds ratio (OR) for mortality on univariate analysis was increased to 2.62 [95% confidence interval (CI): 1.07–6.44] by a VRWG ≥10% and to 3.22 (95% CI: 1.23–8.45) by oliguria. VRWG ≥20% had OR of 3.98 (95% CI: 1.01–15.75; p = 0.049) for mortality. Both VRWG ≥10% (OR 2.71, p = 0.040) and oliguria (OR 3.04, p = 0.032) maintained their statistically significant association with mortality in multivariate models that included sepsis and Apache II score. In conclusion, fluid overload is an important prognostic factor for survival in critically ill AKI patients treated with CRRT. Further studies are needed to elicit mechanisms and develop appropriate interventions.

Predictors of Mortality in a Cohort of Intensive Care Unit Patients With Acute Renal Failure Receiving Continuous Renal Replacement Therapy

Background:Despite the frequent use of continuous renal replacement therapy (CRRT) in the management of acute renal failure (ARF) in the critically ill, predictors of mortality remain unclear. Methods:A registry of all patients initiated on CRRT at a single institution was assembled over an 18-month period, and a subsequent cross-sectional analysis of selected variables was conducted for associations with mortality. Predictors evaluated were age, gender, diagnosis of sepsis, Apache II score, days between ARF diagnosis and initiation of CRRT, creatinine at initiation of CRRT, change in creatinine from baseline and admission to initiation of CRRT, setting of ARF, and prescribed CRRT dose. The principal outcome was mortality at 30 days. Results:Eighty-one individuals met inclusion criteria. Overall mortality for the study was 50.2%. The mean elevation in creatinine from admission to initiation of CRRT was 1.6 mg/dL (141.4 &mgr;mol/L) in those who lived and 2.6 mg/dL (229.8 &mgr;mol/L) in those who died (P = 0.023). Patients admitted with normal renal function who developed ARF while in the hospital had mortality of 56.3%. When available, patients with abnormal renal function at presentation were further classified by either abnormal or normal preadmission creatinine. These patients had mortality of 31.3% and 83.3%, respectively. These differences in mortality were statistically significant. Conclusions:Increased mortality was significantly associated with the magnitude of change in serum creatinine between admission and initiation of CRRT. Also, patient ARF classification was significantly associated with mortality.

Screening for chronic kidney disease in the ambulatory HIV population.

BACKGROUND In 2005, the Infectious Disease Society of America published a guideline recommending that all patients with human immunodeficiency virus (HIV) be screened for kidney disease. We initiated a screening program for kidney disease in a dedicated HIV clinic that follows 1,631 patients. METHODS The screening consisted of a serum creatinine, an estimated glomerular filtration rate (eGFR) as defined by the abbreviated Modification of Diet in Renal Disease equation, and a standard urinalysis for proteinuria. Subjects were identified as having a positive screen if they had 1+ proteinuria or greater on a standard urinalysis or an eGFR of less than 60 ml/min/ 1.73 m2. After 1 year of screening, a retrospective chart review was conducted to determine the efficacy of screening. Bivariate associations were assessed for each outcome. A multiple logistic regression analysis was conducted first with main effects models and then for all variables and interactions. RESULTS 941 subjects that did not have previously documented chronic kidney disease were screened and 96 (10.2%) met the definition of CKD. 9% of subjects had proteinuria and 2.4% had a qualifying eGFR. In multivariate analysis diabetes, hypertension, and low CD4 count (< 200 cells per mm3), low viral load (< 400 copies/ml) displayed strong associations with proteinuria. In the case of reduced eGFR, diabetes and age retained strong associations while the association with hypertension had borderline significance. CONCLUSION This study emphasizes the potential of similar screening programs to identify early or mild CKD in an ambulatory population of patients with HIV.

Do platelet function analyzer-100 testing results correlate with bleeding events after percutaneous renal biopsy?

BACKGROUND Predicting bleeding after percutaneous kidney biopsy (PKB) is difficult. The value of Platelet Function Analyzer-100 (PFA-100) is not studied in this setting. METHODS We undertook a prospective study of PFA-100 collagen/epinephrine (CEPI) and collagen/adenosine diphosphate (CADP) closure times among 56 participants (35 males and 21 females) undergoing PKB under real-time ultrasound (US) visualization at a tertiary teaching hospital. We collected data on age, sex, weight, height, blood pressure (BP), serum creatinine, random urine protein/creatinine ratio, electrolytes, PT/PTT, complete blood count, administration of desmopressin acetate and renal biopsy characteristics. Major outcomes were hematoma formation on US, packed red blood (PRBC) transfusions and hematuria. Data were analyzed with SPSS 16. RESULTS PFA-CEPI was abnormal in 5 (8.93%) and PFA-CADP abnormal in 8 (14.3%) participants. Post-biopsy hematoma formation on US was detected in 11 (19%) participants, 5 (8.9%) had macroscopic hematuria and 4 (7%) required PRBC transfusion. Bleeding events did not correlate with body mass index, baseline BP or with each other. Hematuria and US-observed hematomas did not appear to be clinically relevant. PRBC transfusions showed a significant association with elevated baseline BUN (p = 0.031), creatinine (p = 0.011) and the number of biopsy passes (p = 0.008). PFA-100 CEPI and CADP did not associate with any of the bleeding complications after PKB (p = NS). CONCLUSIONS Measuring PFA-100 is unlikely to add to the care of patients undergoing routine PKB. ClinicalTrials.gov NCT00334204.

C-reactive Protein among Community-Dwelling Hypertensives on Single-agent Antihypertensive Treatment.

BACKGROUND C-reactive protein is a predictor of adverse cardiovascular outcomes. The effect of antihypertensive therapy on C-reactive protein levels is largely unknown. METHOD We undertook a cross-sectional study of CRP levels among participants with primary hypertension on single-agent anti-hypertensive therapy in the community-based biracial Genetic Epidemiology Network of Arteriopathy cohort. Linear regression models were used to assess the association of anti-hypertensive medication class with log-transformed C-reactive protein after adjustment for age, gender, ethnicity, body mass index, smoking, diabetes, HMG-Co-A reductase inhibitor use, achieved blood pressure control (<140/90 mmHg), serum creatinine and urine albumin-to-creatinine ratios. RESULTS There were 662 participants in the cohort taking single-agent therapy for hypertension. Median C-reactive protein levels differed across participants: 0.40 mg/dL for those on diuretics, 0.34 mg/dL on calcium channel blockers, 0.25 mg/dL on beta blockers and 0.27 mg/dL on renin-angiotensin-aldosterone system inhibitors (p<0.001). With multivariable adjustment, the group on renin-angiotensin-aldosterone system inhibitors had a 20% lower mean CRP on average than the group on diuretics (p=0.044), differences between other medication classes were not apparent. Heart rate had a strong association with C-reactive protein (p < 0.001). CONCLUSIONS Antihypertensive medication class may influence inflammation, particularly in patients on RAAS inhibitors.

Ambulatory blood pressure monitoring and peri-hemodialysis blood pressures in a southeast US hemodialysis unit.

AIMS End-stage renal disease (ESRD) patients on dialysis are perceived to have difficult-to-control blood pressure (BP) and commonly treated with complex antihypertensive regimens. Our hypothesis was that peri-dialysis BP will overestimate the true burden of hypertension in these patients. SUBJECTS AND METHODS We performed 44-h ambulatory blood pressure monitoring (ABPM) in 43 patients recruited from the University of Mississippi outpatient dialysis unit. Data collected included routine peri-dialysis blood systolic blood pressure (SBP), diastolic blood pressure (DBP), weight gain, and demographic information. We investigated whether the pre-dialysis or post-dialysis blood pressure would better correspond to the ABPM results. RESULTS The mean age of participants was 50.5 ± 12.05 years, 95% African-American, and 44% diabetic with an average dialysis vintage of 31.1 ± 30 months. The mean SBP and DBP were 164.6/87.9 mmHg ± 22.3/15 before dialysis, 151.5/81.3 mmHg ± 24.1/13 after dialysis and 136/80.6 mmHg ± 23.5/14.7 during ABPM. There were wide limits of agreements between peri-dialysis BP and ABPM, the largest with pre-dialysis SBP (28.5 ± 16.6 mmHg) and the least with post-dialysis DBP (0.7 ± 10 mmHg). With both peri-dialysis BP measurements as explanatory variables in a linear regression model, only the post-dialysis SBP (β 0.716; p < 0.001) but not pre-dialysis SBP (β 0.157; p = 0.276) had a significant independent association with ABPM systolic BP. For DBP, both pre-dialysis (β 0.543; p = 0.001) and post-dialysis (β 0.317; p = 0.037) values retained correlation with DBP on ABPM. CONCLUSION Peri-dialysis measurements overestimated true BP burden in this Southeastern U.S. cohort of ESRD patients. When BP readings from outside the dialysis unit are notavailable, assessment of BP control should focus pre-dialysis on DBP and post-dialysison both SBP and DBP.

357 SCREENING FOR CHRONIC KIDNEY DISEASE IN HUMAN IMMUNODEFICIENCY VIRUS: THE RENAL CLINIC PERSPECTIVE.

Purpose In June of 2005, the Infectious Disease Society of America released guidelines recommending that all patients with human immunodeficiency virus (HIV) be screened for chronic kidney disease (CKD) with serum creatinine and urinalysis for protein. In 10/05 we began a screening program for CKD in an infectious disease clinic that cares for approximately 1,400 patients with HIV. As an adjunct to the screening program, we founded a “CKD in HIV” clinic to handle the associated consultations. In this abstract, we present our experience during the first year of the program. Methods Data were obtained through review of clinic and hospital records. We documented patient demographics, general health data, HIV-specific data, renal-specific data, and short-term management plans, as well as outcome for each patient referred to our clinic. Results Thirty-six patients were referred to the CKD in HIV clinic during 10/2005-9/2006. Nineteen of 36 referrals were detected by the screening program. The reason for referral was variable. Nine of 36 (25%) were referred for nephrotic range proteinuria, and 12 of 36 (33%) were referred for non-nephrotic range proteinuria. Ten of 36(28%) had reduced GFR without proteinuria. Seven of 36 (19%) of referrals never fulfilled their clinic appointment. Of the patients seen in clinic, the mean age was 44 (± 10). Ninety-three percent were African American and 79% were male. Sixty-five percent had undetectable viral loads and 69% had CD4 > 200 at the time of their clinic evaluation. Seventy-nine percent were on antiretroviral therapy (ART). The mean urine protein/creatinine ratio for patients with proteinuria was 3.49 ± 5.3. Nine patients underwent renal biopsy: three had HIV-associated nephropathy (HIVAN), three had non-HIVAN focal segmental glomerulosclerosis, two had immune complex disease, and one had diabetic nephropathy. Management changes following CKD consultation were frequent, including initiation of renin-angiotensin system blockade and modification or initiation of ART, and in two cases, steroids were initiated. Conclusion In a brief period of time, a number of referrals have been made to the CKD in HIV clinic. Pathology was varied, and management changes were frequent. We feel that a dedicated CKD/HIV clinic has a role in the management of HIV patients.

362 AMBULATORY BLOOD PRESSURE MONITORING IN THE DIALYSIS POPULATION: IS IT ESSENTIAL?

Background Hypertension is endemic in the dialysis population. Nephrologists rely on routine blood pressure (RBP) measurements of predialysis blood pressure (Pre-BP) and postdialysis blood pressure (post-BP) to assess hypertension. Current K-QOQI guidelines recommend target pre-BP and post-BP of 140/90 and 130/80 mm Hg, respectively. The purpose of this study was to assess the relationship of RBP to ambulatory blood pressure (ABP) measurements and to determine the burden of uncontrolled hypertension in our hemodialysis population with ABP measurements. Methods RBP measurements were made by trained dialysis staff with patients after sitting 5 minutes before and after dialysis. Six RBP measurements were averaged, pre- and postdialysis. ABP was measured between the fifth and sixth RBP measurement over the 44-hour interdialytic period with Spacelab ABP monitors. Mean ± SD BP (mm Hg) using both techniques was compared using the paired t-test. Results With n = 35, the mean ABP was 135.5 ± 22.8/80.3 ± 15.1. Mean pre-BP averaged 162.6 ± 22.4/88.2 ± 13.9 (p Conclusion ABP demonstrates BP significantly less than either the pre/post dialysis blood pressures. Routine pre/post blood pressures therefore may overestimate the true burden of hypertension in this patient population. When blood pressure is measured using an average of ABP, a significantly lower percentage of participants were above blood pressure targets.