Outpatient Hemodialysis Unit Research Articles

Quantifying the role of factors that limit attainment of K/DOQI urea reduction ratio dialytic goal

For many ESRD patients who are prescribed a certain level of hemodialysis (HD), delivered dose often does not achieve prescription. While various causes have been well-documented in the literature, there are no available data that may be used in predicting the likelihood of achieving a particular urea reduction ratios (URR) goal based on the number of these factors present. This study evaluated URRs of all patients in an outpatient HD unit for a 6-month period to identify factors significant in attaining goal in order to predict likelihood of goal attainment based on number of factors present. The inclusion criterion in this study was any HD patient during the study period with > or = 3 monthly URR measurements. Of 203 patients, 169 qualified for 900 treatments. A database was created for each patient that included demographics, factors affecting K(urea), time and access. After grouping percentages of patients with URR > or = 70%, 65 - < 70%, and < 65%, we studied a subset of 107 patients (568 treatments) that had at least 1 URR < 70% to identify factors associated with a URR of > or = 65% vs. < 65%. To determine factors predictive of URR > or = 65%, a sum percentage across all treatments was created for each patient. Mean percentages were compared between groups created by constant characteristics (e.g. gender, DM). Variables, e.g. catheters, were summarized as a percentage for each patient, and these percentages were correlated with rate of URR > or = 65%. Time was assigned a value of 0 (prescribed), positive (longer), negative (shorter), summarized as per-patient mean. After these factors were identified, each treatment was reviewed to determine the percentage of treatments > or = 65% with the number of statistically significant factors present. The average, across all patients, of percentage of treatments meeting URR > or = 65% was 87.95% while a mean of 66.65% met URR > or = 70%. Factors associated with percentage of treatments per patient not meeting K/DOQI goal included catheter use (Spearman's correlation = -0.31, p = 0.001), blood flow < 90% of prescription (Spearman's correlation = -0.17, p = 0.041), younger age (> or = 61 years vs. < 61 years, p = 0.001: patients > or = 61 years had a higher percentage of URR > or = 65%), inadequate access for prescribed blood flow (Spearman's correlation = -0.32, p = 0.001), actual time vs. prescribed time (Spearman's correlation = 0.25, p = 0.009), and HD w/o heparin (Spearman's correlation = -0.21, p = 0.031). In 178 treatments, all having "good" values (no catheter, blood flow > or = 90% prescribed, age < or = 61 years, etc.), the percentage of treatments meeting URR of < or = 65 was 96.1%. With 1 bad value factor: 83.8% of 216 treatments met goal, 2 bad value factors: 71.7% of 106 met goal, 3 bad value factors: 60.5% of 43 met goal. With 4 or 5 bad value factors: only 36.1% of 25 treatments met goal. Significant factors in meeting adequacy defined by K/DOQI in rank order (excluding age) include inadequate access for prescribed blood flow, catheter use, time, lack of heparin and inability to achieve blood flow > or = 90% prescribed. A direct correlation exists between number of these factors present and K/DOQI goal attainment in a given treatment.

Observational Study of an Arts-in-Medicine Program in an Outpatient Hemodialysis Unit

Long-term hemodialysis is associated with impaired quality of life (QOL) and depression, which are thought to worsen compliance with the treatment regimen. With the success of our hospital's Arts-in-Medicine Program, we launched a similar set of activities in the long-term dialysis unit and sought to measure their effects. At baseline and 6 months, we administered the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and Beck depression scales to 46 patients (44% men; mean age, 52 years) and assessed their percentage of achieved dialysis time, interdialytic weight gain, and predialysis laboratory results. We tested for a relationship between these variables and Arts-in-Medicine Program participation (low and high; 51% and 49%). Arts in Medicine was offered each shift, led by artists, and included artwork, crocheting, crafts, seasonal displays, poetry, and playing musical instruments. At 6 months, the patients, nurses, technicians, and physicians subjectively believed that Arts in Medicine had a positive impact on the unit. In paired comparisons to baseline, there was significant improvement in SF-36 scores for Role-Physical (mean values, 34.4 to 38.7; P = 0.04), less weight gain (3.6 to 3.2 kg; P = 0.02), greater serum carbon dioxide content (20.4 to 22.5 mEq/L [mmol/L]; P < 0.01), greater phosphate levels (5.3 to 5.7 mg/dL [1.71 to 1.84 mmol/L]; P = 0.04), and a trend to less depression (Beck score, 15.3 to 12.1; P = 0.07). Regression analyses showed that high participation correlated with improved SF-36 scores for Social Function (11.1-unit increase; P = 0.01), Bodily Pain (7.6-unit increase; P = 0.04), and Role-Physical (6.6-unit increase; P = 0.06), as well as a trend to greater albumin levels (0.11 g/dL [1.1 g/L]; P = 0.08), but with greater phosphate (0.8 mg/dL [0.26 mmol/L]; P = 0.01) and lower calcium levels (0.3 mg/dL [0.07 mmol/L]; P = 0.07). Participation in a new Arts-in-Medicine Program correlated with improved QOL measures, and there were encouraging trends for depression, as well as certain laboratory and hemodialysis parameters.

Pruritus in hemodialysis patients

BackgroundPruritus is one of the most bothersome symptoms in patients on maintenance hemodialysis (HD), however little progress is seen in our understanding of its pathogenesis. The aim of this study was to evaluate the frequency of pruritus in HD patients in Tehran, Iran, and to correlate its presence and intensity with relevant clinical and laboratory parameters.MethodsOne hundred sixty-seven patients on maintenance HD at three out-patient HD units were enrolled in the study. Itch intensity was scored as mild, moderate and severe. Some relevant clinical and laboratory parameters (age, sex, xerosis, presence of neuropathy, duration of dialysis, history of atopy and laboratory findings including hematocrit, creatinine, urea, calcium, phosphorus, parathyroid hormone [PTH] and alkaline phosphatase) were evaluated.ResultsPruritus was found in 41.9% of patients. The intensity of itching was mild, moderate and severe, in 51.4%, 11.4% and 37.7% of patients, respectively. In 22 patients (31.4%) pruritus intensified during and after dialysis. There was no significant difference in the serum levels of creatinine, blood urea nitrogen, calcium, phosphorus, alkaline phosphatase, PTH and hematocrit between patients with and without pruritus. Age, sex, xerosis, underlying renal disease, history of atopy and duration of haemodialysis were not significantly different between the two groups. However, neuropathy was significantly more common in the pruritic group (63.8% versus 42.1%) (pv = 0.006).ConclusionClinical neuropathy was the only significant finding in the pruritic group in our study. This finding justifies further research on nerve function and neurotransmitters in hemodialysis patients and the introduction of new drugs targeting neuropathy.

Patients receiving maintenance hemodialysis with low vs high levels of nutritional risk have decreased morbidity

Objective To compare the demographic and clinical characteristics and outcomes (morbidity) of 442 patients receiving maintenance hemodialysis who are at different levels of nutritional risk. Design A retrospective, longitudinal, chart review. Setting/subjects An urban, outpatient hemodialysis unit in New York City. Subjects were stratified according to their number of nutritional risk factors: zero to one=low risk, two to three=moderate risk, four to six=high risk. Main outcome measures Mean values for serum albumin <37 g/L, creatinine <884 μmol/L, total cholesterol <4.42 mmol/L, normalized protein nitrogen appearance <0.9 g/kg/day, weight change > −2.5 kg, and body mass index <24. Morbidity indicators were frequency and duration of hospitalizations. Statistical analyses Descriptive statistics, analysis of variance, and χ 2 analysis were used to summarize data and to analyze mean differences between the groups and differences in categorical variables, respectively. Results Compared with the high-risk group, the majority of subjects in the low-risk group were younger, male, and did not have diabetes; fewer had two or more comorbidities. The high-risk group had 75% more hospitalizations and spent 195% more days in the hospital than the low-risk group. Conclusions Declining values of the nutritional risk factors and higher hospitalization rates were present in the high-risk group. Older subjects, those with diabetes, and those with two or more comorbidities comprised the majority of the high-risk group. More aggressive nutrition counseling and interventions may be needed for high-risk group members to determine if their risk for morbidity could be reduced.

Resolution of Catastrophic Anti Phospholipid Antibody Syndrome with Acute Renal Failure after Treatment with Rituximab.

Antiphospholipid antibody syndrome (APS) is a thrombophilic disorder defined by the presence of recurrent thrombosis associated with anticardiolipin antibodies (ACA). To date, there is no effdective therapy for this condition. Rituximab, a chimeric monoclonal antibody B Cells has been shown to be effective in autoimmune disorders. Sporadic abstracts have reported the disappearance of ACA after Rituximab treatment. We have successfully treated a patient with primary catastrophic APS and renal failure with Rituximab. Case Report: A thirty seven year old male with history of DVT, ischemic cardiomyopathy and cerebrovascular accident was admitted to the Hospital for the treatment of acute renal failure and thrombocytopenia. Physical examination was significant for cognitive deficits, mild hepatomegaly, generalized livido reticulairs, and acrocyanosis. Laboratory data revealed platelet count of 97000, creatinine 3.4 mg/dl, IgG ACA titer of 43.8 and negative IgM ACA and ANA. He had proteinuria with benign urinary sediment. Kidney biopsy showed thrombotic microangiopathy. Plasmaphersis was initiated and hemodialysis for the rapidly progressing renal failure. He continued his treatment in an outpatient hemodialysis unit while on Coumadin. Four weekly cycles of Rituximab were given as an outpatient. Serial laboratory investigations showed gradual normalization of the platelet count and disappearance of the IgG ACA. Gradually renal function recovered and hemodialysis was discontinued after three months. He remains in remission with no further thrombotic events.Conclusion: Rituximab is promising in the treatment of APS and must be considered in the first;line treatment of catastrophic APS. A clinical trial is necessary to test the feasibility of discontinuing anticoagulation in these patients.PERTINENT LABORATORY DATADATEHEMOGLOBINPLATELETSCREATININEACA TITER03/21/021.411/15/0314.4973.411/21/0312.51006.243.812/01/0312.2222ON DIALYSIS16.101/01/0414.1276ON DIALYSIS20.903/17/0414.1276ON DIALYSIS05/05/0411.33303.3NEGATIVE

Patterns of antihypertensive medication use in hemodialysis patients

Patterns of antihypertensive drug use in patients undergoing long-term hemodialysis therapy were studied. Patients attending seven outpatient hemodialysis units in Ohio were eligible for the study if they had been receiving the treatment for at least three months. Demographic and clinical data were obtained from patient interviews and computerized databases, and blood pressure (BP) measurements were obtained before dialysis. Labeled names and dosages of antihypertensive drugs were recorded from containers the patients brought with them. Patients were asked to describe their adherence to the medications, their ability to afford the drugs, and their knowledge and beliefs about hypertension. Physical impairments in taking medication were also evaluated. The frequency of hypertension was 89% in the 270 participants. Antihypertensive drugs were prescribed for 76% of the patients; 25% required three or more drugs. Hypertensive patients who were not receiving antihypertensive drugs (14%) had significantly higher BP than patients who were. Calcium-channel blockers were prescribed for 60% of patients, angiotensin-converting-enzyme inhibitors for 33%, and beta-blockers for 34%. Eighty-three percent said the cost of drugs was never a problem, and 23% said they sometimes forgot to take their medication. Almost all patients said they would not stop taking antihypertensive drugs if they were feeling better and agreed that monitoring BP was important. Twenty-two percent could not read the warning on a standard tablet container, and 12% could not remove one tablet from the container. Multidrug antihypertensive therapy was common among hemodialysis patients and was associated with significantly lower BP; calcium-channel blockers were the most frequently prescribed agents. Most patients said they could afford drugs and reported good adherence to antihypertensive drug therapy.

Differences in perceptions by stage of fluid adherence

Objective: The purpose of this study was to determine in a group of hemodialysis patients whether perceptions of barriers to and benefits of adherence to fluid limitations, perceived seriousness of and susceptibility to the consequences of nonadherence, self-efficacy, and thirst differed by stage of fluid adherence. Design: Cross-sectional descriptive design. Setting: There were 147 participants from rural, suburban, and urban outpatient hemodialysis units. Results: Significant differences were found in perceived benefits, barriers, seriousness, susceptibility, and thirst intensity by stage of fluid adherence. There were no significant differences in self-efficacy by stage of fluid adherence. Conclusion: Stage of fluid adherence may be important to consider when designing interventions to reduce fluid intake.

The relationship between serum albumin and hydration status in hemodialysis patients

Objective: A decreased serum albumin level predicts poor survival in end-stage renal failure. Hypoalbuminemia is multifactorial and related to poor nutrition, inflammation, and comorbid disease. Overhydration is also common in renal replacement therapy patients, and hemodilution may also contribute to a low serum albumin level. Design: Crosssectional observational study. Setting: Outpatient hemodialysis unit of a district general hospital. Subjects: We investigated the relationship of serum albumin to C-reactive protein (CRP) and hydration state in 49 unselected hemodialysis patients (28 men). Methods: Patients were assessed predialysis and postdialysis at their clinical dry weight. Extracellular fluid volume (Vecf) and total body water (Vtbw) were estimated by whole-body bioelectric impedance. Vecf was expressed as a percentage of Vtbw (Vecf%Vtbw). Predialysis CRP, predialysis and postdialysis serum albumin, and body weight were measured. Normalized protein catabolic rate (nPCR) and KT/V urea were calculated. Results: Predialysis and postdialysis serum albumin levels were 36.9 g/L (95% CI, 35.7 and 38.1) and 41.4 g/L (95% CI, 39.7 and 43.3), respectively (P <.0001). Mean weight change was 2.0 ± 1.2 kg. Predialysis and postdialysis serum albumin levels were negatively correlated with CRP (before: r = −0.393, P <.005; after: r = −0.445, P =.001) and positively with nPCR (before: r = 0.336, P =.018; after: r = 0.353, P =.013). Predialysis serum albumin level correlated with predialysis Vecf%Vtbw (r = −0.384, P =.006) and postdialysis serum albumin level with postdialysis Vecf%Vtbw (r = −0.654, P <.0001). In multivariate analysis, predialysis albumin was dependent on nPCR (P =.04), CRP (P <.0001), and predialysis Vecf%Vtbw (P =.002), and postdialysis albumin was dependent on nPCR (P =.01), CRP (P =.002), and postdialysis Vecf%Vtbw (both P <.0001). The increase in albumin was strongly correlated with both change in actual weight (r = −0.651, P <.0001) and change in Vecf%Vtbw (r = −0.684, P <.0001). Conclusion: In unselected hemodialysis patients, serum albumin level is dependent on nPCR, CRP, and extracellular fluid volume. This relationship persists after dialysis, suggesting that many patients remain fluid overloaded at their postdialysis dry weight. © 2002 by the National Kidney Foundation, Inc.

Tuberculosis exposure of patients and staff in an outpatient hemodialysis unit

Background: Patients receiving hemodialysis are generally considered to be at increased risk of developing tuberculosis (TB). We evaluated a 13-station chronic outpatient hemodialysis unit associated with a community hospital in northern California. Within 6 months, there were 2 incident source cases in the unit of active smear positive pulmonary tuberculosis; the first in a health care worker (HCW), diagnosed April 3, 1998, and the second in a patient undergoing dialysis treatment in October 1998. We describe the cases; the evaluation of exposures; and the institution of an intentional prospective TB control plan, designed specifically for the unique hemodialysis setting. Methods: We evaluated 23 HCWs twice and 89 patients undergoing hemodialysis treatment who were exposed to case 1 and 38 patients who were exposed to case 2. All 23 HCWs had documented prior negative Sierbert purified protein derivative of tuberculin (PPD) status and were retested at 12 weeks after exposure. None of the patients had documentation of PPD status. All of the patients were skin-tested initially with use of the 2-step method, and those with positive test results were offered isoniazid (INH). Results: One of the 23 HCWs' negative baseline PPD skin test status converted after exposure to case 1, and none of the remaining 22 converted after exposure to case 2. Twelve of 89 exposed patients with no prior skin test record had positive results for PPD after initial testing with the 2-step method. Three of the 12 (25%) patients were treated with INH at the discretion of their attending nephrologist. The 77 patients with negative results for PPD still had negative test results when retested at 3 months. None of 38 patients who underwent dialysis on the same schedule as source case 2 had a converted PPD test. Restriction fragment length polymorphism on TB isolates from both source cases ultimately showed them to be unrelated strains. Conclusion: Our experience with these exposures suggests that TB screening of patient populations undergoing renal dialysis—though they have intrinsic high anergy rates—is advisable with a designed prospective plan before any inadvertent and/or repetitive exposure of that population to active TB. A planned intentional TB control program increases HCW awareness of TB, establishes baselines for evaluation, decreases “panic” in the event of subsequent exposures, and emphasizes the rationale for preventive therapy. (Am J Infect Control 2002;30:307-10.)

A comparison of standardized versus “usual” blood pressure measurements in hemodialysis patients

Hypertension is very common and contributes to the high cardiovascular morbidity in patients undergoing chronic hemodialysis therapy. However, the accuracy of blood pressure measurement in this population has not been well studied. We conducted a cross-sectional study of 270 patients at seven outpatient hemodialysis units. Predialysis and postdialysis seated blood pressure readings obtained by the dialysis unit using automated blood pressure monitors were significantly higher than readings obtained by a research nurse following standard procedures for blood pressure measurement (14.3/7 mm Hg higher predialysis; P < 0.01; 13.6/4.4 mm Hg higher postdialysis; P < 0.05). In 55% of patients, the postdialysis systolic blood pressure measured in the dialysis unit was at least 10 mm Hg higher than the standard reading. Bland-Altman analyses indicated poor agreement between the two readings. This study shows a marked discrepancy between routine dialysis unit and standardized blood pressure measurements. Blood pressure is frequently overestimated by routine dialysis unit readings. In light of these findings, efforts should be made to standardize blood pressure readings in hemodialysis units based on American Heart Association recommendations for blood pressure measurement. © 2002 by the National Kidney Foundation, Inc.

EVALUATION OF UREMIC PRURITUS AT AN OUTPATIENT HEMODIALYSIS UNIT

Pruritus is a common complaint among end stage renal disease patients and has been associated with poor outcome. We characterized this problem at our outpatient hemodialysis unit. Seventy patients were surveyed over a two-day period. A visual analog scale was used to evaluate the intensity of itching. Location of itching and temporal relationship to dialysis was assessed by questionnaire. Laboratory parameters were evaluated to differentiate between those who itched and those who did not itch. Seventy percent of patients reported pruritus either during and/or between hemodialysis sessions. Itch intensity ranged from mild to severe. Forty-five percent of patients itched in three or more areas with the back and legs most commonly reported. Laboratory parameters were unable to differentiate between patients who itched and those who did not itch. Itching remains a common problem in hemodialysis patients. New treatments for patients resistant to standard therapies are needed.

Cocaine use, hypertension, and end-stage renal disease

Cocaine use has been associated with both acute renal failure and hypertension (HTN), but only recently have data suggested it may lead to a chronic insidious form of renal failure. We designed a cross-sectional study to compare the association of cocaine use in hemodialysis patients with and without a diagnosis of HTN-related end-stage renal disease (HTN-ESRD). Two hundred one black patients from two outpatient hemodialysis units in an urban community were evaluated. There were 193 eligible patients, 106 men and 87 women, aged 49.28 ± 14.4 years. A history of significant cocaine use before dialysis was reported by 55 of 193 subjects (28.5%). A diagnosis of HTN-ESRD was reported in 49 of 55 cocaine users (89.1%) compared with 64 of 138 nonusers (46.38%; odds ratio, 9.44; 95% confidence interval, 3.79 to 23.49; P < 0.0005). Of the 113 subjects with HTN-ESRD, 49 subjects (43.4%) had a history of cocaine abuse, either alone or in combination with other drugs. Subjects with HTN-ESRD with cocaine use were younger than those without cocaine use (40.7 ± 9.0 versus 53.8 ± 15.3 years; P < 0.0005) and had a shorter reported duration of HTN (5.3 ± 5.4 versus 12.7 ± 9.8 years; P < 0.0005, adjusted for age and sex). In our urban dialysis population, a clinical diagnosis of HTN-ESRD was strongly associated with a history of cocaine use and earlier onset of ESRD. Cocaine should be considered as a cause of ESRD in patients without a clear cause of renal failure. © 2001 by the National Kidney Foundation, Inc.

The effect of dietary supplements on the nPCR in stable hemodialysis patients

Objective: To investigate whether (1) dietary supplements raise the normalized protein catabolic rate (nPCR) and/or further improve the nutritional status of stable hemodialysis patients who have both a low nPCR and a low dietary protein intake, <1.2 g/kg body weight/day; and if (2) protein intake measured by nPCR reflects protein intake measured by estimated food diaries in stable patients. Design: Prospective experimental study with a single intervention group. Setting: Hospital outpatient hemodialysis unit. Subjects: Seventeen stable chronic hemodialysis patients (10 men, 7 women) were studied over 8 months. Intervention: Subjects with both a low nPCR and dietary protein intake <1.2 g/kg body weight/day received dietary supplements for the first 2 months. Measurements to assess protein intake and nutritional status were taken at baseline and repeated at the end of 2 months, and at 6 months postintervention. Main outcome measure: nPCR, dietary protein intake using 7-day estimated food diaries, serum urea, serum albumin, serum creatinine, serum bicarbonate, dialysis adequacy ( Kt V ), and body mass index (BMI). Results: Dietary supplements significantly increased both the nPCR and the total protein intake at 2 months (1.21 ± 0.26, 1.10 ± 0.12, respectively) compared with baseline (0.95 ± 0.18, 0.75 ± 0.19, respectively) and 8 months (0.99 ± 0.12, 0.78 ± 0.21, respectively), P < .0001, respectively. There was no change in the nutritional status of the subjects. There was a significant difference between the nPCR and the dietary protein intake at baseline, P < .004; at 2 months, P < .047; and at 8 months, P < .001. Conclusion: Dietary supplements can significantly increase the nPCR and dietary protein intake in stable hemodialysis patients with a low nPCR and dietary protein intake. Because a low nPCR is associated with a high morbidity and mortality rate, it may be prudent to supplement such patients. The use of the nPCR to quantify dietary protein intake in stable hemodialysis patients should be used with caution.

Outpatient High-Dose Urokinase Infusion Improves Dialysis Catheter Longevity: A Prospective Observational Study

Catheter thrombosis is a major limiting factor affecting catheter survival in hemodialysis (HD). A previous retrospective study highlighted the utility of outpatient intradialytic high-dose urokinase (HDU) infusion in the treatment of HD catheter thrombosis. The present study was designed to prospectively evaluate the effectiveness of 250 000 IU urokinase given as a 3-hour infusion during HD. The infusion would follow detection of a drop in blood flow thought to be secondary to thrombosis [a "thrombotic event" (TE)] after exclusion of nonthrombotic causes of drop in blood flow [a "nonthrombotic event" (NTE)], such as systemic hypotension or suboptimal position of the catheter on x ray. An “event” was defined as a drop in pump blood flow by greater than or equal to 20% of the prescribed blood flow. Twenty patients (mean age 57.7 years; 13 males) with documented or potentially long-term catheters were recruited (total catheters used, 30) from an outpatient HD unit. A variety of catheter types were used. Catheter position was confirmed on x ray. Hemodialysis sessions were monitored for 6 months or until catheter removal (whichever was earlier). Thrombotic and NTEs (mostly related to drop in blood flow) were noted. The use of intradialytic HDU infusions was monitored. Improvement was defined as reestablishment of blood flow to within 10% of prescription. There were 24 TEs in 11 patients and 15 NTEs in 7 patients. Twenty-one of 22 (95%) TEs responded to HDU, with complete restoration of blood flow; in 1/22 HDU-treated instances there was a partial response. For 2/24 TEs the patients underwent catheter stripping with good results. Twelve of 15 NTEs occurred in the first 2 weeks of catheter placement versus 6/24 TEs (p = 0.001, chi-square). Catheter survival was longer than 24 weeks in 12/30 catheters. Nine catheters were lost to NTEs. No catheter was lost secondary to a TE. It is therefore concluded that intradialytic outpatient HDU is useful for the treatment of HD catheter thrombosis. It may obviate/reduce the need for catheter stripping or replacement. Randomized controlled trials with this approach are needed. A higher proportion of NTEs tended to occur earlier after catheter placement compared to TEs.

Outpatient High-Dose Urokinase Infusion Improves Dialysis Catheter Longevity: A Prospective Observational Study.

Catheter thrombosis is a major limiting factor affecting catheter survival in hemodialysis (HD). A previous retrospective study highlighted the utility of outpatient intradialytic high-dose urokinase (HDU) infusion in the treatment of HD catheter thrombosis. The present study was designed to prospectively evaluate the effectiveness of 250 000 IU urokinase given as a 3-hour infusion during HD. The infusion would follow detection of a drop in blood flow thought to be secondary to thrombosis [a "thrombotic event" (TE)] after exclusion of nonthrombotic causes of drop in blood flow [a "nonthrombotic event" (NTE)], such as systemic hypotension or suboptimal position of the catheter on x ray. An "event" was defined as a drop in pump blood flow by greater than or equal to 20% of the prescribed blood flow. Twenty patients (mean age 57.7 years; 13 males) with documented or potentially long-term catheters were recruited (total catheters used, 30) from an outpatient HD unit. A variety of catheter types were used. Catheter position was confirmed on x ray. Hemodialysis sessions were monitored for 6 months or until catheter removal (whichever was earlier). Thrombotic and NTEs (mostly related to drop in blood flow) were noted. The use of intradialytic HDU infusions was monitored. Improvement was defined as reestablishment of blood flow to within 10% of prescription. There were 24 TEs in 11 patients and 15 NTEs in 7 patients. Twenty-one of 22 (95%) TEs responded to HDU, with complete restoration of blood flow; in 1/22 HDU-treated instances there was a partial response. For 2/24 TEs the patients underwent catheter stripping with good results. Twelve of 15 NTEs occurred in the first 2 weeks of catheter placement versus 6/24 TEs (p = 0.001, chi-square). Catheter survival was longer than 24 weeks in 12/30 catheters. Nine catheters were lost to NTEs. No catheter was lost secondary to a TE. It is therefore concluded that intradialytic outpatient HDU is useful for the treatment of HD catheter thrombosis. It may obviate/reduce the need for catheter stripping or replacement. Randomized controlled trials with this approach are needed. A higher proportion of NTEs tended to occur earlier after catheter placement compared to TEs.

Incidence and outcome of Staphylococcus aureus bacteremia in hemodialysis patients

Staphylococcus aureus bacteremia is frequently associated with metastatic complications and infective endocarditis (IE). The Duke criteria for the diagnosis of IE utilize echocardiographic techniques and are more sensitive than previous criteria. The documentation of IE in patients undergoing hemodialysis (HD) has become increasingly important in order to avoid the overuse of empiric vancomycin and the emergence of antibiotic resistance. Patients who developed S. aureus bacteremia while undergoing HD at a tertiary medical center or one of four affiliated outpatient HD units were identified. Clinical outcome (death, metastatic complications, IE, and microbiologic recurrence) was assessed during hospitalization and at three months after discharge. Transthoracic and transesophageal echocardiograms were performed and the Duke criteria were used to diagnose IE. Pulse field gel electrophoresis was performed to confirm genetic similarity of recurrent isolates. Four hundred and forty-five patients underwent hemodialysis for 5431.8 patient-months. Sixty-two developed 65 episodes of S. aureus bacteremia (1.2 episodes/100 patient-months). Complications occurred in 27 (44%) patients. Bacteremia recurred in patients who dialyzed through polytetrafluorethylene grafts (44.4% vs. 7.1%, P = 0.0.01), and there was a trend to increased recurrence in patients who received only vancomycin (19.5% vs. 7.1%, P = 0.4). IE was diagnosed in 8 patients (12%), six of whom had normal transthoracic echocardiograms. Sensitive echocardiographic techniques and the Duke criteria for the diagnosis of IE should be used to determine the proper duration of antibiotic therapy in hemodialysis patients with S. aureus bacteremia. This diagnostic approach, coupled with early removal of hardware, may assist in improving outcomes.

Effect of potassium concentration in dialysate on total body potassium

Objective: To investigate the effects of the presence/absence of potassium in the dialysate on total body potassium content in stable hemodialysis patients. Design: Randomized selection. Setting: Outpatient chronic hemodialysis unit at the James A. Haley VA Hospital in Tampa, Florida. Patients: Six adult hemodialysis patients (mean age 48 ± 11.61 years, range 32–65 years) participated in this study. They were all males, four African-Americans and two Caucasians. Intervention: Subjects in a random order received dialysis using a dialysate containing no potassium for 3 months, followed by a 2 mEq/L of potassium for another 3 months. Total body potassium measurements and routine blood analysis were taken at baseline and after each three month period. All subjects received diet instruction pre and monthly on a 3 g/day potassium dietary restriction. Main outcome measured: There were no significant differences in the amount of total body potassium concentration between the two different dialysates containing 0 or 2 mEq/L potassium. Mean values of serum albumin were significantly higher when the subjects were dialyzed on a 0 potassium bath. Conclusion: The use of dialysate containing 0 or 2 mEq/L potassium concentration does not make a significant difference with regard to total body potassium concentration and maybe advantageous for the patients in terms of more freedom in nutritional intake as demonstrated by a significant increase in serum albumin when they were dialyzed on a 0 potassium bath.

Hemolytic reactions mechanically induced by kinked hemodialysis lines

Ten hemolytic reactions occurred in our outpatient hemodialysis unit over a 12-month period (December 1989 to December 1990). Eight patients were hospitalized and one died. All patients developed severe abdominal or back pain an average of 2.5 hours into a 4-hour hemodialysis session using a bleach/formaldehyde reprocessed hollow-fiber cupraphan dialyzer (average reuse, three times) with blood flow rates of 375 mL/min. All had visible hemolysis in a spun hematocrit, seven had a significant decrease in hematocrit, and six developed pancreatitis. Hemolysis was further confirmed by a decrease in haptoglobin in all patients and an increase in lactic dehydrogenase in all but the last case. Investigation of each episode failed to find an abnormality in dialysate temperature or tonicity; dialysate or water levels of copper, zinc, nitrates, chloramine, or formaldehyde; or blood pump or venous alarm. Hemolytic reactions continued despite changing to 15-gauge needles, removing bleach from the reuse procedure, or stopping reuse. During the eighth episode, a kink was noted in the arterial blood line. Two subsequent hemolytic reactions occurred, and in each kinks were found in the arterial blood line, either in the excess tubing between the blood pump and drip chamber or in the predialyzer. No further hemolytic reactions occurred after changing to a new arterial blood line without redundant tubing and securing all lines. Hemolytic reactions occurring during hemodialysis have many etiologies, including mechanical trauma, which we report may result from kinking of dialyzer lines. With new blood lines on the market, attention to this aspect of dialysis is mandatory.

An outbreak of fatal fluoride intoxication in a long-term hemodialysis unit.

To determine the cause of an outbreak of acute illness and death in a long-term hemodialysis unit. A retrospective cohort and case-control study of patients receiving hemodialysis and a laboratory study of a model deionization system to purify water for hemodialysis. An outpatient hemodialysis unit of a university hospital. 12 patients who became severely ill after hemodialysis treatment and 20 patients who did not become ill after receiving hemodialysis treatment in the same unit. Medical and dialysis unit records were reviewed to identify and characterize cases. Fluids for dialysis were tested for toxic substances, and fluoride was measured in patients' serum. Resistivity and fluoride were measured in effluent from a model deionization system operated in the same way as the system associated with illness. During five consecutive hemodialysis shifts, 12 of 15 patients receiving dialysis treatment in one room became acutely ill, with severe pruritus, multiple nonspecific symptoms, and/or fatal ventricular fibrillation (3 patients). None of 17 patients treated in the adjacent room became ill (P < 0.0001). Death was associated with longer hemodialysis time and increased age compared with other patients who became ill. Serum concentrations of fluoride in the sick patients were markedly increased to as high as 716 mumol/L, and the source of fluoride was the temporary deionization system used to purify water for hemodialysis only in the affected room. Operation of a model deionization system showed how fluoride was adsorbed and then displaced in a massive efflux. Because deionization systems are used widely in hemodialysis and can cause fatal fluoride intoxication, careful design and monitoring are essential.

Chronic hemodialysis patients. Part I: Characterization and drug-related problems.

To describe medication use in hemodialysis patients and to characterize the potential drug-related problems that may occur in this population. All patients being dialyzed during the study period who were responsible for taking their own medications and who were able to provide an accurate medication history were included in this study. A pharmacist administered a structured medication history and drug therapy review protocol known as the Focused Drug Therapy Review Program to identify potential drug-related problems. This process was modified for a hemodialysis population. Outpatient hemodialysis unit at a university-affiliated hospital. Thirty patients with endstage renal disease requiring hemodialysis were enrolled in the study. On average, 10 prescription and 2 prescribed nonprescription medications were used per patient. The incidence of potential adverse effects and medication allergies or intolerances averaged 5.5 and 2.2 per patient, respectively. Twenty patients (67 percent) reported missing an average of 3.4 (range 1-11) doses of medication per month. A total of 216 potential drug-related problems (encompassing both prescribing choices and patient behaviors) were identified by the pharmacist; the categories of drug selection and medication compliance contained the greatest number of potential problems (24 and 23 percent, respectively). Hemodialysis patients use a large number of medications, which increases the risk for adverse reactions and other drug-related problems. The types of potential drug-related problems identified are amenable to pharmacist input. Thus, such patients should be targeted for clinical pharmacy intervention.