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Biomedical subjects

Michael V Rocco

Publications and source records attributed to Michael V Rocco.

24 records · Page 2Linked to original sources

Relationship between volume status and blood pressure during chronic hemodialysis.

BACKGROUND: The relationship between volume status and blood pressure (BP) in chronic hemodialysis (HD) patients remains incompletely understood. Specifically, the effect of interdialytic fluid accumulation (or intradialytic fluid removal) on BP is controversial. METHODS: We determined the association of the intradialytic decrease in body weight (as an indicator of interdialytic fluid gain) and the intradialytic decrease in plasma volume (as an indicator of postdialysis volume status) with predialysis and postdialysis BP in a cross-sectional analysis of a subset of patients (N=468) from the Hemodialysis (HEMO) Study. Fifty-five percent of patients were female, 62% were black, 43% were diabetic and 72% were prescribed antihypertensive medications. Dry weight was defined as the postdialysis body weight below which the patient developed symptomatic hypotension or muscle cramps in the absence of edema. The intradialytic decrease in plasma volume was calculated from predialysis and postdialysis total plasma protein concentrations and was expressed as a percentage of the plasma volume at the beginning of HD. RESULTS: Predialysis systolic and diastolic BP values were 153.1 +/- 24.7 (mean +/- SD) and 81.7 +/- 14.8 mm Hg, respectively; postdialysis systolic and diastolic BP values were 136.6 +/- 22.7 and 73.9 +/- 13.6 mm Hg, respectively. As a result of HD, body weight was reduced by 3.1 +/- 1.3 kg and plasma volume was contracted by 10.1 +/- 9.5%. Multiple linear regression analyses showed that each kg reduction in body weight during HD was associated with a 2.95 mm Hg (P=0.004) and a 1.65 mm Hg (P=NS) higher predialysis and postdialysis systolic BP, respectively. In contrast, each 5% greater contraction of plasma volume during HD was associated with a 1.50 mm Hg (P=0.026) and a 2.56 mm Hg (P < 0.001) lower predialysis and postdialysis systolic BP, respectively. The effects of intradialytic decreases in body weight and plasma volume were greater on systolic BP than on diastolic BP. CONCLUSIONS: HD treatment generally reduces BP, and these reductions in BP are associated with intradialytic decreases in both body weight and plasma volume. The absolute predialysis and postdialysis BP levels are influenced differently by acute intradialytic decreases in body weight and acute intradialytic decreases in plasma volume; these parameters provide different information regarding volume status and may be dissociated from each other. Therefore, evaluation of volume status in chronic HD patients requires, at minimum, assessments of both interdialytic fluid accumulation (or the intradialytic decrease in body weight) and postdialysis volume overload.

Adult↗

Comparison of causes of death using HEMO Study and HCFA end-stage renal disease death notification classification systems. The National Institutes of Health-funded Hemodialysis. Health Care Financing Administration.

Few data are available on the accuracy of death classification in patients with end-stage renal disease (ESRD). The National Institutes of Health-funded Hemodialysis (HEMO) Study allows the opportunity to compare cause of death recorded on the Health Care Financing Administration (HCFA) Death Notification Form 2746 with death classified by the HEMO Study. The HEMO Study cause of death is determined by trained HEMO Study Outcome Review Committee physicians. In this interim analysis, there were 220 deaths coded by both classification systems. Using the HEMO Study classification system, the most common cause of death was ischemic heart disease (20.4%), followed by arrhythmia and conduction problems (10.4%), cerebrovascular disease (8.6%), and non-access-related infections (7.7%). Using the HEMO Study final death classification as the reference standard, most differences in the two classification systems were related to coding of heart disease. Sensitivity for the HCFA classification ranged from 9.1% for congestive heart failure to 91.7% for malignancy, whereas specificity values were all greater than 78%. Positive predictive values ranged from 11.8% for other heart disease and conditions to 100% for malignancy and hepatobiliary disease, whereas negative predictive values were all greater than 85%. The kappa statistic between the two death classification systems ranged from 0.12 for congestive heart failure to 0.95 for malignancy. Studies using death classification from the HCFA ESRD death notification form for deaths secondary to either cardiovascular diseases or unknown causes should be interpreted cautiously.

Aged↗

Nutritional status in the HEMO Study cohort at baseline. Hemodialysis.

The nutritional status of the first 1,000 patients randomized into the Hemodialysis (HEMO) Study was analyzed at baseline when they received their typical dialysis dose (equilibrated Kt/V = 1.30 +/- 0.22) and dialysis membrane. This is the largest study to date of the nutritional status of chronic hemodialysis patients. The mean (+/- SD) values for these parameters included a serum albumin level of 3.65 +/- 0.38 g/dL, a dietary energy intake of 22.9 +/- 8.4 kcal/kg/day, a dietary protein intake of 0.93 +/- 0.36 g/kg/day, and a double pool normalized protein catabolic rate (enPCR) of 1.00 +/- 0.25 g/kg/day. The percentage of patients below HEMO Study nutritional standards of care included 29% of patients with a serum albumin level less than 3.5 g/dL, 76% of patients with a dietary energy intake less than 28 kcal/kg/day, 61% of patients with a dietary protein intake less than 1.0 g/kg/day, and 52% of patients with an enPCR of less than 1.0 g/kg/day. There was a strong correlation between dietary protein intake and dietary energy intake (r = 0.74, P < 0.0001). Significant correlations were also evident between serum albumin and double pool PCR and between dietary protein intake and double-pool PCR. Kt/V and membrane flux were not predictive of baseline dietary protein intake, dietary energy intake, or serum albumin level. Thus, a majority of patients in the HEMO Study had protein and energy intake levels and enPCR levels that were below National Kidney Foundation Kidney Dialysis Outcome Quality Improvement (NKF-K/DOQI) guidelines.

Aged↗

Comparison of mortality and intermediate outcomes between medicare dialysis patients in HMO and fee for service.

End-stage renal disease (ESRD) is the only disease entitlement for Medicare; therefore, most patients with ESRD have Medicare coverage. Patients with ESRD are prohibited by law from enrolling in health maintenance organizations (HMOs), the only group prohibited within Medicare. However, they may remain in an HMO if they enrolled in such a plan before their kidneys failed. Thus, it is possible to compare patients with ESRD in HMOs with those in fee-for-service (FFS) plans. To determine whether mortality, transplantation rates, and intermediate outcomes differed between Medicare ESRD beneficiaries enrolled in HMO versus FFS providers, a retrospective cohort analysis was performed of patients with ESRD from three Health Care Financing Administration data sets containing administrative and outcome information for Medicare ESRD beneficiaries from 1990 to 1998. On December 31, 1998, a total of 278,510 prevalent patients with ESRD were in FFS plans, and 18,332 patients were in HMOs. HMO patients were older and more likely to be white and male and have diabetes mellitus and comorbid cardiovascular conditions than FFS patients. Unadjusted 2-year survival rates were 48.4% and 49.3% for FFS and HMO patients, respectively. In a multivariate model, HMO status had no significant effect on mortality, which was greater with older age, male sex, and white race. In 1998, unadjusted renal transplantation rates were 23.5% and 15.5% for FFS and HMO patients, respectively; age adjustment abrogated the apparent difference. For FFS and HMO patients, adequate hemodialysis was delivered to 72% and 82%, and 56% and 62% had hematocrits greater than the benchmark, respectively. There was no statistical difference in these outcomes in multivariate comparison. In conclusion, care by HMO for patients with an expensive chronic illness can achieve outcomes similar to those for FFS patients. Claims of poorer care and worse outcomes for patients with ESRD enrolled onto an HMO, an argument used to justify continued prohibition against widespread participation by patients with ESRD, are not supported.

Dialysis↗

Correlates of sleep behavior among hemodialysis patients. The kidney outcomes prediction and evaluation (KOPE) study.

BACKGROUND: Given the importance of sleep to overall physical and mental well-being, we sought to identify the correlates of seven sleep disturbances in a cross-sectional study of a biracial population of male and female patients treated with hemodialysis. METHODS: Univariate and multivariate analyses of a cohort study of adult patients with end-stage renal disease. Demographic, psychosocial, clinical, and health and physical functioning variables were included. RESULTS: Waking up during the night (57%) and waking up too early (55%) were the most commonly reported sleep problems. Multivariate analyses consistently indicated that levels of pain, depressive symptoms, and physical functioning were consistently associated with the seven sleep disturbances. CONCLUSION: Sleep disturbances are common in patients with end-stage renal disease. Physical and mental well-being were consistently related to the seven sleep disturbances.

Activities of Daily Living↗

Risk factors for early mortality in U.S. peritoneal dialysis patients: impact of residual renal function.

BACKGROUND: Potential risk factors for 1-year mortality, including the peritoneal component of dialysis dose, residual renal function, demographic data, hematocrit, serum albumin, dialysate-to-plasma creatinine ratio, and blood pressure, were examined in a national cohort of peritoneal dialysis patients randomly selected for the Centers for Medicare and Medicaid Services End-Stage Renal Disease (ESRD) Core Indicators Project. METHODS: The study involved retrospective analysis of a cohort of 1,219 patients receiving chronic peritoneal dialysis who were alive on December 31, 1996. RESULTS: During the 1-year follow-up period, 275 patients were censored and 200 non censored patients died. Among the 763 patients who had at least one calculable adequacy measure, the mean [+/- standard deviation (SD)] weekly Kt/V urea was 2.16 +/- 0.61 and the mean weekly creatinine clearance was 66.1 +/- 24.4 L/1.73 m2. Excluding the 365 patients who were anuric, the mean (+/- SD) urinary weekly Kt/V urea was 0.64 +/- 0.52 (median: 0.51) and the mean (+/- SD) urinary weekly creatinine clearance was 31.0 +/- 23.3 L/1.73 m2 (median: 26.3 L/1.73 m2). By Cox proportional hazard modeling, lower quartiles of renal Kt/V urea were predictive of 1-year mortality; lower quartiles of renal creatinine clearance were of borderline significance for predicting 1-year mortality. The dialysate component of neither the weekly creatinine clearance nor the weekly Kt/V urea were predictive of 1-year mortality. Other predictors of 1-year mortality (p < 0.01) included lower serum albumin level, older age, and the presence of diabetes mellitus as the cause of ESRD, and, for the creatinine clearance model only, lower diastolic blood pressure. CONCLUSION: Residual renal function is an important predictor of 1-year mortality in chronic peritoneal dialysis patients.

Adult↗