Browsing by Subject "Renal Dialysis"
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Item Acute Effect of High vs Low Dialysate Sodium on Endothelial Cell Function During Hemodialysis(2013-01-22) D'Silva, Kristin; Molina, Christopher; van Buren, Peter; Kim, Catherine; Inrig, JulaBACKGROUND: Intradialytic hypertension (HTN), a rise in blood pressure that occurs during hemodialysis (HD) treatments in up to 15% of patients, is associated with higher morbidity and mortality. The cause of intradialytic HTN is unknown but may be due to endothelial cell (EC) dysfunction. In vitro exposure of ECs to high sodium (Na+) concentration promotes EC stiffness and imbalances in vasoconstrictors (endothelin-1 [ET-1]) and vasodilators (nitric oxide [NO]). We hypothesized that, among patients with intradialytic HTN, exposure to high dialysate Na+ would lead to a decrease in NO and increase in ET-1 during HD. METHODS: We performed a 3-week, 2-arm, randomized crossover study among 16 HD patients with intradialytic HTN and compared the effects of high dialysate-to-serum Na+ gradients (5 mEq/L above participants' baseline Na+) vs low dialysate-to-serum Na+ gradients (5 mEq/L below baseline Na+ with lower limit of 134 mEq/L) on intradialytic changes in nitrite and ET-1. Differences between treatments were compared with repeated measures mixed linear regression and included randomization arm (high - low Na+ vs low - high Na+), treatment effect (high vs low Na+), subject, time and session. RESULTS: Study participants (N=16) had an average age of 58.8 years, 38% were black, 56% were Hispanic, and 94% were male. Intradialytic changes in NO and ET-1 with high and low dialysate-to-plasma Na+ gradients are shown in Figure 1. In the primary comparison of high vs low dialysate-to-serum Na+ gradient, there were no significant differences in intradialytic levels of NO or ET-1 (Table 1). However, when compared by randomization arm, participants who received the low dialysate-to-serum Na+ gradient followed by high compared to those who received the high dialysate-to-serum Na+ gradient followed by low had a significant decrease in ET-1 (parameter estimate -0.49 pg/mL, p=0.04) and significant increase in nitrite during hemodialysis (parameter estimate +0.16 nM, p=0.02) (Table 1). CONCLUSIONS: Patients who received the low dialysate-to-serum Na+ gradient before the high dialysate-to-serum Na+ gradient had higher levels of nitrite and lower levels of ET-1 throughout the three week study period compared to patients who received the high dialysate-to-serum Na+ gradient before the low dialysate-to-serum Na+ gradient. This suggests that the dialysate Na+ concentration may have longer-term effects on endothelial cell function.Item Aluminum toxicity syndromes in chronic hemodialysis(1987-12-10) Cronin, Robert E.Item The Association Between Tobacco Use and Intradialytic Hemodynamics in Hemodialysis Patients(2018-01-23) Sonderman, Mark; Van Buren, Peter NoelBACKGROUND: Intradialytic hypotension is known to be associated with increased mortality in maintenance hemodialysis patients. Smoking is a modifiable risk factor that is more commonly seen in patients with large decreases in intradialytic blood pressure as compared to any other intradialytic blood pressure pattern. However, the mechanisms of this association are unknown. We sought to explore the effect of lifetime tobacco use on vascular hemodynamics during dialysis. METHODS: We used impedance cardiography to measure total peripheral resistance index (TPRI) in 65 hypertensive hemodialysis patients. Additionally, we obtained blood pressure measurements before, during, and after midweek hemodialysis treatments. We then compared intradialytic hemodynamic changes between never smokers (n=35) and current or former smokers (n=30) using simple and multivariable linear regression. RESULTS: The mean change in TPRI during a single dialysis session was -438 dynes/sec/cm2/m2 in smokers and -105 dynes/sec/cm2/m2 in non-smokers (p=0.1). The intradialytic systolic blood pressure nadir was 115 mmHg in smokers and 123 mmHg in non-smokers (p=0.1). In multivariable linear regression controlling for diabetes, ultrafiltration rate, and other factors associated with intradialytic blood pressure changes, smoking was independently associated with lower nadir SBP (p=0.01) with a trend to also have a greater decrease in TPRI (p=0.08). CONCLUSIONS: Hemodialysis patients with a smoking history demonstrate a tendency towards a greater reduction in intradialytic TPRI as compared to non-smokers, with a significant independent association for lower nadir SBP. Smoking status should be aggressively ascertained in dialysis patients with significant intradialytic hypotension, but further studies are required to determine the effect of smoking cessation on intradialytic hemodynamics.Item Blood pressure management in hemodialysis patients(2016-06-03) Van Buren, PeterItem Demographics and Quality of Life in Unfunded Patients Receiving Regular Emergent Dialysis(2014-02-04) Hogan, Andrew; Rigdon, Daniel; Suter, RobertINTRODUCTION: Patients with End Stage Renal Disease (ESRD) must undergo hemodialysis several times per week for renal dysfunction. Chronic dialysis drastically affects the lifestyles of ESRD patients, as it is time-consuming and uncomfortable. A high number of unfunded ESRD patients present to the Emergency Department (ED) at Parkland Hospital for dialysis. These patients accounted for over 7300 ED visits in 2009. Providing emergent dialysis via the ED has been shown to be more costly than providing scheduled dialysis. To date, all psychometric analyses of demographics and quality of life in chronic dialysis patients focus on insured patients in traditional dialysis centers. This study attempts to acquire and analyze such data on the emergent dialysis population at Parkland Hospital. Data will ultimately be compared to control patients from the Parkland system. METHODS: A demographic survey developed at UT Southwestern and the established "Kidney Disease Quality Of Life (KDQOL(TM)) Instrument" were presented to ESRD patients seeking dialysis in the Parkland ED. A comprehensive list of 165 suitable patients was obtained from Parkland Nephrology. With a goal of 80% recruitment of those identified, patients were recruited upon presentation 24 hours a day, 7 days a week for a 4-week period beginning on July 8, 2013. In total, 55 data points from each patient were aggregated. RESULTS: Of 101 chronic dialysis patients approached during the initial 4 weeks, 88 completed the survey. Although 39% of listed patients were not surveyed by the end of the 4 weeks, raw data collection has recently been completed. Demographic data reveal a predominantly male, Hispanic, middle-aged, undocumented, and uninsured ESRD patient population seeking dialysis in the Parkland ED. The KDQOL data indicate a majority of surveyed patients rate their current health negatively, while only 9% do so positively. Additional data quantifying the impact of chronic dialysis on patient lifestyles await analysis. DISCUSSION: The demographic data reveal that 68% of the chronic dialysis patients thus surveyed have lived in the USA for more than 5 years, yet only 15% received a diagnosis requiring dialysis over 5 years ago. This finding seems to contradict the currently accepted idea that the need for dialysis is the primary motivating factor bringing most of these patients to the USA. Quality of life data remains to be compared between the unfunded emergent population and the Nephrology clinic population. Descriptors for the emergent patients are expected to be more negative, or at best equivalent to those for the scheduled patients. Considering the higher cost of emergent dialysis, the results of this comparison are expected to support an argument for providing scheduled dialysis for unfunded ESRD patients.Item Dialysis in chronic renal disease(1962-11-29) Carter, Norman W.Item The Effect of Extracellular Volume Status on Intradialytic Hypertension(2014-02-04) Molina, Christopher; Van Buren, Peter; Toto, RobertBACKGROUND: lntradialytic hypertension (HTN), defined as an increase in systolic blood pressure (BP) >10 mmHg from pre to post-hemodialysis (HD),occurs regularly in approximately 15o/o of HD patients. Previous studieshave shown patients with intradialytic HTN display higher overall ambulatory BP and have higher mortality rates when compared to HD controls. As extracellular volume overload contributes to HTN in HD patients, it has been proposed that intradialytic HTN patients have increased extracellular volume. Still, atypical ambulatory BP patterns seen in intradialytic HTN patients suggest extracellular volume may not be a primary determinant of BP in this population. Thus, we hypothesize extracellular fluid volume will be similar in patients with intradialytic HTN and HD controls when adjusting for total body water. METHODS: ln a case control study we recruited hypertensive HD patients with pre HD systolic BP >140 mmHg or post HD systolic BP >130 mmHg. Case subjects with intradialytic HTN were defined as having systolic BP increases >10 mmHg from pre to post-HD. Control subjects were defined as having systolic BP decreases >10 mmHg from pre to post- HD. We obtained measurements of total body water, extracellular water, and intracellular water before and after HD in all subjects using multifrequency bioimpedance spectroscopy. We compared the ratio of extracellular water to total body water between groups using t-tests for pre and post dialysis measurements. RESULTS: Case subjects (n=4) had an average ambulatory systolic BP of 140 mmHg (20) and controls (n=4) had an average of 1a0 (9.8). Before dialysis, case subjects had a ratio of 0.49 (.03) vs. 0.a6 (.02) in controls (p=0.2). After dialysis, the ratio was 0.45 (0.03) in cases and .44 (0.01) in controls (p=0.4). DISCUSSION: The ratio of extracellular water to total body water was similar in subjects with intradialytic HTN both before and after HD compared to HD controls. While a larger sample size will be required to establish whether extracellular volume status is different in this patient population, the results of this study suggest increased extracellular volume is not a distinguishing feature of intradialytic HTN. Further etiologies for increased BP including excessive vascular resistance should be explored to explain the phenomenon of intradialytic hypertension.Item Emergency dialysis for undocumented immigrants: the Parkland experience(2018-06-15) Berger, Joseph RossiItem The ethics of AKI in the ICU: when can (should) you say "no"?(2021-04-13) Moss, Alvin H.Many older adults with kidney failure and comorbidities may not live any longer with dialysis than without it. However, the de facto default practice is to start dialysis in most patients with progressive stage 5 chronic kidney disease. Medical anthropologists have described two factors contributing to the dialysis default: changing societal expectations resulting in a "biomedicalization of aging" and a "technological imperative" reflected in the difficulty of saying "no" to life-extending interventions, regardless of age, frailty, and complicating, debilitating medical conditions. Commentators have noted that default options are powerful and may be harmful to some patients. They have emphasized that to counter the clinical momentum of default options; it is necessary for clinicians to engage such patients and their families intentionally and explicitly in the process of shared decision-making. This lecture will present the evidence for the dialysis default and a patient-centered approach to respond to it.Item Tools to improve survival in dialysis: doing the most with a half-way technology(2019-10-04) Concepcion, MichaelItem A two-headed coin: renal disease and neoplasms (or "heads- you win; tails-I lose")(1981-10-08) McPhaul, John J., Jr.Item Use of dialysis in drug intoxication(1961-10-26) Carter, Norman W.Item When to initiate maintenance dialysis and how much is enough(1996-08-15) Toto, Robert D.Item Why kidney disease always gets worse: what can we do about it?(2014-08-08) Lu, Christopher Y.