Central Systolic and Diastolic Blood Pressure Pressures during Hemodialysis.

Maintaining fixed dry weight and controlling cardiovascular risk factors during hemodialysis (HD) requires well-controlled blood pressure (BP) with regular measurements. Keeping the BP stable during HD is challenging in some patients with end-stage renal disease (ESRD). Accurate measurement of BP is the key, as it helps prevent intradialytic hypotension. It is still unclear if there is a difference between using the central or peripheral BP measurements in ESRD. To study if there is a significant difference between the central and peripheral BP, we tested the central and peripheral BP in 14 ESRD patients during their HD session. We compared 326 peripheral BP readings with 326 central BP measurements. There was a significant difference noticed with a lower central systolic and pulse pressure and a higher central diastolic and mean arterial pressure as compared with the peripheral pressure readings. Since BP measurement is the major factor to determine target organ hypoperfusion during HD, measuring the central pressure measurements during HD could help mitigating the risk of inducing unnoticed target organ hypoperfusion during HD.

Successful elimination of hemodialysis-related bacteremia and vascular access infection.

Hemodialysis (HD) related bacteremia and dialysis induced infection constitute major risk factors for mortality and morbidity among patients with end stage renal disease. In this retrospective study, we attempted to assess the impact of the infection control protocol introduced in our center on the prevalence of HD related bacteremia and vascular access infection. All the HD sessions performed over 8 years, from January 2004 till the end of December 2011, were included in this study. Over 108 months of the study period, 6161 HD sessions were performed on 118 patients. Demographic data of all the study patients were collected. The type of vascular access as well as the presence of diabetes and hypertension were recorded. During the study period, 15 episodes of dialysis related bacteremia were noted in nine patients. Three of them required hospitalization for administration of parenteral antibiotics. Blood cultures in 93% of the infection episodes (14/15) grew Sphingomonas paucilomobilis. One patient had methicillin resistant Staphylococcus aureus grown on blood culture. The prevalence of HD related bacteremia and vascular access infection in our unit were lower than international published data. The infection control protocol used seems to have been successful in reducing HD related bacteremia and eliminating vascular access infection.

Unusual presentation of renal vein thrombosis with pulmonary artery embolism.

A young 23-year-old male patient presented with a two-day history of right flank pain. He had no history of any significant illnesses in the past. His investigations showed nephrotic range proteinuria with hypoalbuminemia. The patient developed cough and shortness of breath after having a left kidney biopsy. He did not respond to regular respiratory tract infection treatment. The kidney biopsy revealed membranoproliferative glomerulonephritis. Further investigations for the cough showed thromboembolism of the posterior and lateral basal segments of the right lower lobe. Moreover he was found to have thrombosis of the right upper pole renal vein. The patient was started on full anticoagulation along with three days pulse steroid, followed by 1 mg/kg oral steroid. Clinical improvement was noticed within 48 h. After eight weeks the proteinuria decreased from 8.5 gm/day to 1.1 gm/day. The kidney function was normal with eGFR 145 mL/min through the course of the disease. This case represent one of the unusual presentation of nephrotic syndrome with pulmonary and renal vascular thromboembolic events. The response to the combination of anticoagulation and steroid was remarkable.

Determinants and functional significance of renal parenchymal volume in adults.

BACKGROUND AND OBJECTIVES: The significance of renal parenchymal volume and the factors that influence it are poorly understood. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Renal parenchymal volume (RPV) was measured on contrast-enhanced CT scans after exclusion of sinus fat and vessels in 224 healthy subjects evaluated as kidney donors and in a separate cohort of 22 severely obese individuals before and after 6 months of weight loss. GFR was measured by iohexol clearance in 76 of the transplant donors. RPV was correlated with age, GFR, and various anthropometric parameters. RESULTS: In potential transplant donors, RPV correlated with body surface area (BSA; r = 0.68) and was 7% larger in men but did not vary with age or race. Gender and body size were independent determinants of RPV. RPV correlated well with GFR (r = 0.62) and accounted for almost all of the variability in a model of GFR that included age, race, gender, and body surface area. GFR correlated more strongly with RPV than with creatinine-based equations. The same relationship between RPV and BSA was observed in obesity, and RPV decreased with weight loss. CONCLUSIONS: In healthy adults younger than 65 years, renal parenchymal volume is governed by body size and gender but not age or race and is strongly correlated with GFR. This indicates that renal parenchymal volume varies to meet metabolic demand and is closely linked to renal function.

Changes in renal cortical and medullary perfusion in a patient with renal vein thrombosis.

Dynamic renal perfusion computerized tomographic (CT) scan was performed to test the cortical and medullary perfusion in a patient with unilateral renal vein thrombosis secondary to idiopathic focal and segmental glomerulosclerosis (FSGS). Forty mL of Iohexol was injected intravenously. Multiple fixed repeated axial renal CT scan cuts at specific intervals, over the mid pole, were recorded over 400 seconds. Radio density was measured over the aorta, cortex and medulla during that period. Graphs for the radio contrast density against time were plotted. Aortic, cortical and medullary perfusions were calculated by estimating the slopes of the curves. Based on the CT scan findings, perfusion of different parts of the kidney was measured. The reduction in kidney function with renal vein thrombosis seems to be secondary to hypoperfusion of renal cortex and medulla. Further studies are required to confirm this observation. The blood flow to the kidney im-proved within four days after therapy with anticoagulation and pulse steroids. The sequences of events that take place need further studies for validation.

Infection-free hemodialysis: can it be achieved?

Infection is the second most common cause of mortality in patients with end stage re-nal disease (ESRD). Following strict aseptic precautions during a hemodialysis (HD) session could reduce dialysis-related infection, thereby reducing mortality and morbidity rates. This retrospective study was undertaken to identify the prevalence of dialysis-related bacteremia, sepsis, and catheter infections during HD at Bahrain Specialist Hospital, Bahrain, after following rigid infection control procedures. All HD sessions performed between January 2004 and December 2007 were included. Strict aseptic precautions were observed for every patient in our dialysis unit. The patients' demographic characteristics as well as presence of hypertension (HTN), diabetes mellitus (DM) and use of immunosuppressive drugs were recorded. Results of culture of dialysis catheter tip were collected for all catheters removed or changed during the study period. Catheter surface culture yielding more than 15 colonies and catheter lumen culture yielding more than 1000 CFU/mL were considered positive. All episodes of rigors, chills, bacteremia, and sepsis were recorded. Overall, a total of 1084 HD sessions performed on 46 patients were studied. The mean age of the study patients was 55.2 years (SE 2.5). Fifty four percent were male, 50% had DM, 85% had HTN and 11% were immunosuppressed. With implementation of strict aseptic precautions no catheter-related infection, bacteremia or sepsis was found. Culture of 50 dialysis catheters showed Diptheroid in three patients, MRSE in two patients and MSSE, Enterobacter, and Klebsiella in one patient each. None of the study patients had signs or symptoms of infection or bacteremia. Our study further indicates that following strict aseptic precautions during HD sessions can reduce, if not eliminate, infection as a major cause of mortality and morbidity.

Reduced renal function in patients with simple renal cysts.

BACKGROUND: Sporadic renal cysts not associated with genetic polycystic disorders are common and generally thought to be of no clinical significance. Since multiple cysts frequently develop in end-stage renal disease (ESRD), we tested the hypothesis that cysts that are solitary or few in number are an early manifestation of reduced renal function. METHODS: We evaluated 561 hospitalized patients who underwent contrast-enhanced, abdominal computed tomography (CT) and correlated clinical characteristics and parameters of renal function with the presence or absence of renal cysts. RESULTS: Age ranged from 16 to 100 years, mean serum creatinine concentration was 0.88 mg/dL (range 0.4 to 2.1 mg/dL), and mean estimated creatinine clearance was 94 mL/min/1.73 m(2) (range 22 to 218 mL/min/1.73 m(2)). The presence of cysts was significantly correlated with older age (P < 0.001), higher serum creatinine concentration (P < 0.002), and lower estimated creatinine clearance (P < 0.001). In a multivariate analysis, including age and gender, estimated creatinine clearance still correlated with the presence of cysts (P= 0.009). When patients were grouped by age, estimated creatinine clearance correlated with cysts in patients <40 years and 40 to 59 years, but not in patients 60 to 79 years or > or =80 years. There was no association of cysts with hypertension or proteinuria. In patients with cysts, serum creatinine increased progressively but not significantly with cyst number, and did not correlate with size or distribution of cysts. Renal parenchymal volume was slightly but not significantly reduced in patients with cysts. CONCLUSION: The presence of kidney cysts, even single cysts, is associated with reduced renal function in hospitalized patients younger than 60 years. This relationship may be obscured by the reduced renal function and the high incidence of cysts in older patients. These results suggest that acquired cystic kidney disease may begin early in the course of renal disease and that underlying renal disease should be considered in individuals with renal cysts prior to age 60 years.

Reduced kidney size in patients with simple renal cysts.

BACKGROUND: Renal cysts frequently occur in the absence of genetic diseases but their significance is unknown. Since multiple cysts develop in many patients with advanced renal disease, we tested the hypothesis that isolated cysts are associated with early nephron loss. METHODS: All inpatient and outpatient sonograms performed by the Renal Division since 1995 were reviewed and, after exclusion of duplicate studies, patients with genetic cystic disorders, complex cysts, hydronephrosis, peripelvic cysts, end-stage renal disease and transplanted kidneys, 2526 were selected for this study, of which 385 had one or more cysts. Maximum renal length was used as an indication of size, and renal function was estimated by serum creatinine concentration. RESULTS: Both right and left kidney length were significantly less in patients with cysts (P < 0.0001), independent of which kidney contained the cyst(s). Renal lengths were less in patients with multiple cysts as opposed to single cysts but not in patients with bilateral cysts as compared to unilateral cysts. Cysts were twice as frequent in solitary kidneys than in dual kidneys (P = 0.01). In outpatients matched for age and gender, those with cysts had a higher serum creatinine concentration but with borderline significance (P = 0.06). Multivariate analysis revealed that age, gender, and renal length were each independent variables and together accounted for one third of the incidence of cysts. CONCLUSION: Kidney size is reduced in patients with simple renal cysts noted on renal sonography, and cysts may be associated with reduced renal function. This suggests that isolated cysts are an indication of nephron loss in patients with renal abnormalities.