Carpal tunnel syndrome. It's not just with keyboards.

CTS is often preventable. Take care of your hands when at work or at play when performing repetitive tasks, especially if there is also force, vibration, or awkward postures. Try to keep your wrists in a neutral posture, use tools and techniques that minimize required force, have a proper working surface height, design and arrange your work space to minimize the CTS risk factors, and make sure to have enough breaks to have sufficient recovery time. Avoid being overweight. If you experience pain similar to that described with CTS, see your medical doctor. He or she can help differentiate CTS from other upper extremity disorders and can help identify the most appropriate treatment approach. Remember, CTS is not just with keyboards.

Hospitalization risks between Renagel phosphate binder treated and non-Renagel treated patients.

AIM: We evaluated 152 sevelamer hydrochloride treated Medicare patients on hemodialysis in a case-controlled study matching 152 randomly selected non-sevelamer hydrochloride treated Medicare patients from the same dialysis facilities and time period. The main outcomes evaluated were the risk of all-cause hospitalization and per-member per-month (PMPM) Medicare expenditures in the follow-up period. PATIENTS AND METHODS: Medicare patients were identified from a total of 195 patients who were included in a long-term safety and efficacy clinical trial evaluating sevelamer hydrochloride [Chertow et al. 1999a]. The average serum calcium-phosphorus product as well as lipid profiles improved in the sevelamer hydrochloride treated group during the trial. Sevelamer treated patients were matched with randomly selected Medicare patients for age, gender, race, diabetic status, and geographic location. Comorbid conditions were characterized and sequential Cox regression models were applied with the outcome being risk of first hospitalization in a 17- month follow-up period. RESULTS: Across all four models, the relative risk of hospitalization was 46% to 54% less in the sevelamer hydrochloride treated group, as compared to the case control group (significant at the p-value 0.03 level). Overall, Medicare expenditures for the control patients per-member per-month were US-$4,745, compared to US-$3,368 in the sevelamer hydrochloride treated patients. CONCLUSION: Sevelamer hydrochloride treated patients had a 50% lower likelihood of hospitalization in the follow-up period after adjustments for the differences in the population. Potential bias may exist between groups because of differences in baseline characteristics that could not be adjusted for within the study design. We feel that to further advance this area, a randomized clinical trial should be performed.

Impact of hematocrit on morbidity and mortality.

It has been 10 years since epoetin-alpha was approved by the federal Food and Drug Administration for use in end-stage renal disease patients. Over this period of time, clinical studies have shown a relationship between the correction of anemia and improved cardiac function, cognitive ability, sexual function, and exercise capacity. Recent large epidemiological studies have shown that mortality and morbidity are reduced when the hematocrit (Hct) level is in the range 33% to 36%, and the National Kidney Foundation's Dialysis Outcomes Quality Initiative (NKF-DOQI) guidelines recommend a target Hct of 33% to 36% to enhance patient outcomes. The most recent mortality studies show that Hcts less than 30% (or hemoglobins less than 110 gm/L) are associated with an 18% to 40% increased associated risk of death and hospitalizations. Higher Hcts in the 33% to 36% range appear to be associated with a 7% reduced risk of death and hospitalizations compared with patients with Hcts of 30% to less than 33%. Patients with sustained Hcts of 33% to 36% over 1 year appear to have the best outcome compared with patients with Hcts that fall. These studies suggest that the factors that may influence patients' ability to move into higher Hct ranges need to be determined to enhance patient outcomes. Dramatic improvement in hemodialysis patient Hct levels has occurred since 1989. Mortality and hospitalization studies support the NKF-DOQI target Hct range of 33% to 36% as providing the best associated outcomes.

Hematocrit levels and associated Medicare expenditures.

Clinical studies and the National Kidney Foundation-Dialysis Outcomes Quality Initiative guidelines suggest that a target hematocrit of 33% to less than 36% is appropriate for patient benefit. Previous studies have shown an association of lower risks for death and hospitalization when hematocrits were 33% to less than 36%. In this study, we assessed the relationship between hematocrit value and associated Medicare expenditures, analyzing incident Medicare hemodialysis patients from January 1, 1991, through June 30, 1995. All patients survived at least 90 days to normalize eligibility and an additional 6-month entry period to assess comorbidity and hematocrit values. All patients were followed up from July 1, 1991, through December 31, 1996. We assessed the association between hematocrit values in the 6-month entry period and the Medicare-allowable Part A and Part B per-member-per-month (PMPM) expenditures in the follow-up period, controlling for other variables, including patient demographic characteristics, comorbid conditions, and severity of disease. We found that hematocrits of 33% to less than 36% and 36% and higher were associated with lower Medicare-allowable payments in the follow-up period. Compared with reference patients with hematocrits of 30% to less than 33%, the Medicare-allowable PMPM expenditures were significantly greater for patients with hematocrits less than 27% and 27% to less than 30% (12. 7% and 5.3%, respectively), and the Medicare-allowable PMPMs were significantly less for patients with hematocrits of 33% to less than 36% and 36% and higher (6.0% and 8.2%, respectively). Although these findings suggest that the treatment of anemia may be associated with significant savings in total patient Medicare expenditures, caution should be considered because these findings are associations and should not be deemed as showing causality.

Impact of disease severity and hematocrit level on reuse-associated mortality.

Prior studies on reuse-associated mortality have presented conflicting results and included few adjustments for disease severity or hematocrit levels. To evaluate the impact of patient and provider characteristics on reuse-associated mortality, we developed a period-prevalent model with a 6-month entry period. Five cohorts of Medicare hemodialysis patients surviving from July 1 through December 31 of the entry year (1991, 60,985 patients; 1992, 63,081 patients; 1993, 76,018 patients; 1994, 82,899 patients; 1995, 91,761 patients) were followed up for the next year. Using a basic Cox regression survival model (M-1) including age, sex, race, renal diagnosis, prior end-stage renal disease time, unit age, unit size, water treatment, dialysate, and germicide, results were compared with those using a more inclusive model (M-4) adding dialyzer type (conventional or high efficiency/high flux), unit designation (hospital based or freestanding), unit profit status, comorbidity, disease severity, and hematocrit. The previous association of for-profit units with increased mortality was not present after 1994. Whereas the M-1 analysis showed better survival in reuse units after 1991, the more complete M-4 analysis showed no difference in the risk for mortality between reuse and no-reuse units. We conclude that mortality rates in the United States from 1991 to 1995, when adjusted comprehensively for patient and unit characteristics, were not different in units that practiced reuse and those that did not.

Mortality risks of peritoneal dialysis and hemodialysis.

Studies of outcomes associated with dialysis therapies have yielded conflicting results. Bloembergen et al showed that prevalent patients on continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD) had a 19% higher mortality risk than hemodialysis patients, and Fenton et al, analyzing Canadian incident patients, found a 27% lower risk. Attempting to reconcile these differences, we evaluated incident Medicare patients (99,048 on hemodialysis, 18,110 on CAPD/CCPD) from 1994 through 1996, following up to June 30, 1997. Patients were followed to transplantation, death, loss to follow-up, 60 days after modality change, or end of the study period. For each 3-month survival period, we used an interval Poisson regression to compare death rates, adjusting for age, gender, race, and primary renal diagnosis. A Cox regression was used to evaluate cause-specific mortality, and proportionality was addressed in both regressions by separating diabetic and nondiabetic patients. The Poisson regressions showed CAPD/CCPD to have outcomes comparable with or significantly better than hemodialysis, although results varied over time. The Cox regression found a lower mortality risk in nondiabetic CAPD/CCPD patients (women younger than 55 years: risk ratio [RR] = 0. 61; Cl, 0.59 to 0.66; women age 55 years or older: RR = 0.87; Cl, 0. 84 to 0.91; men younger than 55 years: RR = 0.72; Cl, 0.67 to 0.77; men age 55 years or older: RR = 0.87; Cl, 0.83 to 0.92) and in diabetic CAPD/CCPD patients younger than 55 (women: RR = 0.88; Cl, 0. 82 to 0.94; men: RR = 0.86; Cl, 0.81 to 0.92). The risk of all-cause death for female diabetics 55 years of age and older, in contrast, was 1.21 (Cl, 1.17 to 1.24) for CAPD/CCPD, and in cause-specific analyses, these patients had a significantly higher risk of infectious death. We conclude that, overall, within the first 2 years of therapy, short-term CAPD/CCPD appears to be associated with superior outcomes compared with hemodialysis. It also appears that patients on the two therapies have different mortality patterns over time, a nonproportionality that makes survival analyses vulnerable to the length of follow-up. Further investigation is needed to evaluate both the potential explanations for these findings and the use of more advanced statistical methods in the analysis of mortality rates associated with these dialytic therapies.

Hematocrit levels and hospitalization risks in hemodialysis patients.

The association between hematocrit level and future hospitalization risks in hemodialysis patients has not been fully investigated on a national level. A total of 71,717 prevalent Medicare hemodialysis patients who survived a 6-mo entry period from July 1 through December 31, 1993 were studied, and their risk of hospitalizations was evaluated the next year. Five hematocrit groups were defined from Medicare recombinant human erythropoietin-treated patients: <27%, 27 to <30%, 30 to <33%, 33 to <36%, and > or =36%. A Cox regression model was used to investigate the association between hematocrit level and the risk of first hospitalization, and the Andersen-Gill regression model evaluated multiple hospitalizations during the next year, adjusting for patient comorbidity and severity of disease. Compared with the baseline group of 30 to <33%, patients with hematocrit levels <30% had a 14 to 30% increased risk of hospitalization without disease severity adjustment (p = 0.0001) and a 7 to 18% increased risk with disease severity adjustment (p = 0.0001). Patients in the 33 to <36% group had the lowest risk at 0.93 and 0.88 (p = 0.0001), with and without adjustment for disease severity. It is concluded that patients with hematocrits of <30% have an increased risk of future hospitalization, with hematocrit levels between 33 and 36% having the lowest associated risks.

Hematocrit level and associated mortality in hemodialysis patients.

Although a number of clinical studies have shown that increased hematocrits are associated with improved outcomes in terms of cognitive function, reduced left ventricular hypertrophy, increased exercise tolerance, and improved quality of life, the optimal hematocrit level associated with survival has yet to be determined. The association between hematocrit levels and patient mortality was retrospectively studied in a prevalent Medicare hemodialysis cohort on a national scale. All patients survived a 6-mo entry period during which their hematocrit levels were assessed, from July 1 through December 31, 1993, with follow-up from January 1 through December 31, 1994. Patient comorbid conditions relative to clinical events and severity of disease were determined from Medicare claims data and correlated with the entry period hematocrit level. After adjusting for medical diseases, our results showed that patients with hematocrit levels less than 30% had significantly higher risk of all-cause (12 to 33%) and cause-specific death, compared to patients with hematocrits in the 30% to less than 33% range. Without severity of disease adjustment, patients with hematocrit levels of 33% to less than 36% appear to have the lowest risk for all-cause and cardiac mortality. After adjusting for severity of disease, the impact of hematocrit levels of 33% to less than 36% is vulnerable to the patient sample size but also demonstrates a further 4% reduced risk of death. Overall, these findings suggest that sustained increases in hematocrit levels are associated with improved patient survival.

Trends in anemia treatment with erythropoietin usage and patient outcomes.

Recombinant erythropoietin, first approved for Medicare reimbursement in June 1989, was prescribed at initial doses for dialysis patients of 2,500 to 2,700 U per administration independent of hematocrit level. By 1997, however, patients with hematocrits less than 30% were administered 6,000 U/dose, compared with 4,500 U administered to patients with hematocrits of 33% to 36%. Since 1990, the percentage of patients with hematocrits less than 30% decreased from 60% to 22% in 1997, whereas the percentage of patients with hematocrits of 33% to 36% increased from 10% to 30%. In 1997, Medicare initiated the Hematocrit Measurement Audit (HMA) policy, which was directed at reducing the percentage of claims for hematocrits greater than 36% and increasing the stability of the hematocrit levels. The policy change achieved the initial effect but resulted in a reduction of the mean hematocrit as well. The policy was changed in 1998 in response to patient and provider concerns. Mortality studies show that hematocrits less than 30% (or hemoglobin levels < 110 g/L) are associated with an 18% to 40% increased associated risk for death. Higher hematocrits of 33% to 36% appear to be associated with a 7% reduced risk for death. The risk for hospitalization parallels that of mortality. Patients with sustained hematocrits of 33% to 36% over 1 year appear to have the best outcome compared with patients with hematocrits that decrease. The latter are at greater risk than those patients in whom the hematocrits increase. In conclusion, dramatic improvements in hemodialysis patient hematocrits have occurred since 1989. Mortality and hospitalization studies support the National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF DOQI) target hematocrit range of 33% to 36% as providing the best associated outcomes.

Multicenter clinical validation of an on-line monitor of dialysis adequacy.

Quantitation of hemodialysis by measuring changes in blood solute concentration requires careful timing when taking the postdialysis blood sample to avoid errors from postdialysis rebound and from recirculation of blood through the access device. It also requires complex mathematical interpretation to account for solute disequilibrium in the patient. To circumvent these problems, hemodialysis can be quantified and its adequacy assessed by direct measurement of the urea removed in the dialysate. Because total dialysate collection is impractical, an automated method was developed for measuring dialysate urea-nitrogen concentrations at frequent intervals during treatment. A multicenter clinical trial of the dialysate monitoring device, the Biostat 1000 (Baxter Healthcare Corporation, McGaw Park, IL) was conducted to validate the measurements of urea removed, the delivered dialysis dose (Kt/V), and net protein catabolism (PCR). The results were compared with a total dialysate collection in each patient. During 29 dialyses in 29 patients from three centers, the paired analysis of urea removed, as estimated by the dialysate monitor compared with the total dialysate collection, showed no significant difference (14.7 +/- 4.7 g versus 14.8 +/- 5.1 g). Similarly, measurements of Kt/V and PCR showed no significant difference (1.30 +/- 0.18 versus 1.28 +/- 0.19, respectively, for Kt/V and 42.3 +/- 15.7 g/day versus 52.2 +/- 17.4 g/day for PCR). When blood-side measurements during the same dialyses were analyzed with a single-compartment, variable-volume model of urea kinetics, Kt/V was consistently overestimated (1.49 +/- 0.29/dialysis, P < 0.001), most likely because of failure to consider urea disequilibrium. Because urea disequilibrium is difficult to quantitate during each treatment, dialysate measurements have obvious advantages. The dialysate monitor eliminated errors from dialysate bacterial contamination, simplified dialysate measurements, and proved to be a reliable method for quantifying and assuring dialysis adequacy.

Pitfalls of in vivo dialyzer clearance measurement.

Dialyzer small-molecule clearance measurements are commonly made to help identify the cause of inadequate dialysis prescriptions, to determine the efficacy of reuse procedures, or to choose between different types of dialyzers. Clearance measurements can be blood-side- or dialysate-side-based. While blood-side clearance measurement is the classical technique, it suffers from several serious flaws that decrease its accuracy. Chief among these are the inability to accurately measure the blood flow rate and the difficulty in accounting for the presence of nonaqueous components in the blood. Using a dialysate-based clearance measurement technique overcomes these problems for most solutes, provided appropriate guidelines are followed. This article reviews the theory behind both blood- and dialysate-side techniques as well as discussing the practical application of that theory to clearance measurement.

On-line monitoring of the delivery of the hemodialysis prescription.

The BioStat 1000 is a new device which employs dialysate-based urea kinetics to calculate the dose of dialysis (Kt/V) based on a two-pool model and protein catabolic rate (PCR). Previous methods relying on blood sampling techniques were subject to error and difficult to implement. This paper describes the features of the Biostat and the results of the first clinical validation study with an early prototype. The BioStat was found to compare favorably with the reference method of direct dialysate quantification (mDDQ) which had been modified to obtain a "two-pool" Kt/V. In 31 patients no significant difference was found between mean Kt/V from the mDDQ and the mean Kt/V from the BioStat (1.35 +/- 0.33 versus 1.38 +/- 0.36, respectively). The PCR was also not significantly different (53.4 +/- 18.5 g/day versus 51.8 +/- 16 g/day, respectively). The BioStat was demonstrated to be a convenient method producing reliable results.

Anterior subcutaneous transfer of the ulnar nerve in the athlete.

To evaluate the effectiveness of subcutaneous subfascial anterior transfer of the ulnar nerve in the surgical treatment of cubital tunnel syndrome in athletes, we retrospectively reviewed athletes undergoing subcutaneous anterior transfer of the ulnar nerve at the elbow. Criteria for inclusion in the study included active participation in athletic activity, confirmed cubital tunnel syndrome, failure to respond to conservative treatment, and having an anterior subcutaneous subfascial transfer as the only procedure performed. Twenty athletes underwent a total of 21 procedures. Results were evaluated by time to return to sport and a questionnaire developed to evaluate elbow function in the athlete. The athletes returned to full activity at an average of 12.6 weeks. Average subjective postoperative scores were 84. Elbow rating scores averaged 9 (range, 0 to 10). Anterior subcutaneous subfascial transfer of the ulnar nerve is a safe, effective means for treating cubital tunnel syndrome in athletes. The findings in this study are significant in that they confirm the effectiveness of the subcutaneous subfascial transfer procedure in returning the athlete to competition. Of secondary importance is the development of an elbow rating questionnaire appropriate to the athlete.

Three hollow fiber dialyzers.

Hollow fiber dialyzers with a variety of sizes and performance characteristics are presently available for the dialysis of adult patients. We evaluated three currently available follow fiber adult dialyzers in vitro and in vivo during treatment of adult patients. All three dialyzers, Gambro GF-120H, Gambro GF-120L, and Travenol CF-1211 were well suited for the dialysis of adult patients. By considering the clinical status of the patients and the performance characteristics of the dialyzer (solute removal, ultrafiltration, priming volume, etc.), it is possible to employ the follow fiber dialyzer which most precisely meets the needs of the patient, without increasing risk factors associated with hemodialysis.

Time of death, recovery of renal function, development of chronic renal failure and need for chronic hemodialysis in patients with acute tubular necrosis.

We analyzed 432 patients with acute tubular necrosis, dialyzed at the University of Minnesota Dialysis Unit between 1968-1979. Only 135 patients or 31% survived. The median time to death was 5 days and to recovery of renal function was 12 days. Serum creatinine continued to fall for one month after the last dialysis and then stabilized. Ultimate serum creatinine level was directly related to age of patient but not duration of need for dialysis. One-fourth of the patients were left with moderate renal insufficiency (creatinine 1.5-3 mg/dl). Eight of 82 (10%) of the patients with long term (greater than 1 mo follow-up) had severe renal failure (creatinine over 3 mg/dl) and 4 other patients never recovered renal function but needed chronic hemodialysis. Acute renal failure is numerically important but not very time demanding on the capacity of dialysis units. The majority of the patients have no clinical problem of renal dysfunction if they survive their basic disease leading to acute tubular necrosis.

Four new dialyzers.

Dialyzers with a variety of sizes and performance characteristics are presently available for the dialysis of adult patients. We evaluated four currently available disposable adult dialyzers in vitro and in vivo during treatment of adult patients. All four dialyzers, Gambro GLP 1.36m2, 17 mu, Cordis Dow 3500, Gambro GF 120M, and Travenol HD 1000 were well suited to the dialysis of adult patients. By considering the clinical status of the patients and the performance characteristics of the dialyzer (solute removal, priming volume, ultrafiltration, etc.) it is possible to employ a hemodialyzer which more precisely meets the needs of the patient without increasing risk factors associated with hemodialysis.