Do patient-reported measures of symptoms and health status predict mortality in hemodialysis? An assessment of POS-S Renal and EQ-5D.

Introduction Experience with the use of patient-reported outcome measures such as EQ-5D and the symptom module of the Palliative care Outcome Scale-Renal Version (POS-S Renal) as mortality prediction tools in hemodialysis is limited. Methods A prospective survival study of people receiving hemodialysis (N = 362). The EQ-5D and the POS-S Renal were used to assess symptom burden and self-rated health (with a self-rated component). Participants were followed from instrument completion to death or study end. Competing risks survival analysis was used to evaluate associations with time to death, with renal transplant as a competing risk. Findings 32% (N = 116) of participants died over a median (25th-75th centile) of 2.6 (1.41-3.38) years. Factors most notably associated with mortality adjusted hazard ratio (95%CI) included: lower EQ VAS score 2.7 (1.4, 5.2) P = 0.004 (lowest tertile), higher POS-S Renal score 2.4 (1.3, 4.3) P = 0.004 (highest tertile), and lower EQ-5D score 2.6 (1.3, 5.3) P = 0.01 (lowest tertile) as well as the presence of: "problems with mobility?" 2 (1.1, 3.3) P = 0.01, or "problems with usual activities?" 2.1 (1.4, 3.3), P < 0.001. After age adjustment area under the receiver operating curves (AUC) (95%CI) for mortality were: 0.71 (0.62, 0.79) for EQ VAS score, 0.71 (0.63, 0.80) for POS-S Renal-S Renal score, and 0.76 (0.68, 0.84) for EQ-5D score. AUC 95%CI was highest for our fourth model at 0.79 (0.72, 0.86) comprised of individual elements from both instruments and established risk factors. Discussion EQ VAS scores and predictive models based on combinations of elements from the POS-S Renal and EQ-5D instruments may aid in mortality discrimination and possibly in the delivery of supportive care services.

Blood pressure measurement in peritoneal dialysis: which method is best?

BACKGROUND: The optimal approach to monitoring blood pressure (BP) in the peritoneal dialysis (PD) population is unclear. Ambulatory BP monitoring reliably predicts prognosis, but can be inconvenient. The accuracy of home BP monitoring in this population is unproven. The automated BpTRU device (BpTRU Medical Devices, Coquitlam, BC, Canada), which provides an average of up to 6 successive in-office BP measurements, has not been studied in this patient group. METHODS: We studied 17 patients (average age: 54 ± 12 years; 12 men, 5 women; 94% on automated PD) attending a single center. All patients underwent office, home, BpTRU, and ambulatory BP measurement. The reference standard for analysis was daytime ambulatory BP. Correlation between the referent method and each comparator method was determined (Pearson correlation coefficient), and Bland-Altman scatter plots depicting the differences in the BP measurements were constructed. RESULTS: Mean office BP (126.4 ± 16.9/78.8 ± 11.6 mmHg) and BpTRU BP (123.8 ± 13.7/80.7 ± 11.1 mmHg) closely approximated mean daytime ambulatory BP (129.3 ± 14.8/78.2 ± 7.9 mmHg). Mean home BP (143.8 ± 15.0/89.9 ± 28.1 mmHg) significantly overestimated mean daytime systolic BP by 14.2 mmHg (95% confidence interval: 4.3 mmHg to 24.1 mmHg; p = 0.008). Bland-Altman plots demonstrated poorest agreement between home BP and daytime ambulatory BP. No patient had "white-coat hypertension," and only 1 patient had false-resistant hypertension. Most patients showed abnormal nocturnal dipping patterns (non-dipping: n = 11; reverse-dipping: n = 5; normal dipping: n = 1). CONCLUSIONS: We report a novel finding that BP measurement using the BpTRU device is more accurate than home BP measurement in a PD population. Potential explanations for this observation include poor home BP measurement technique, use of poorly validated home BP measurement devices, or a reduced prevalence of white-coat effect among PD patients. Our study also confirms that, in the PD population, BP measurements vary considerably with patient location, time of day, and measurement technique.

Serum phosphate varies with degree of proteinuria in nephrotic syndrome and is associated with elevated pulse wave velocity.

BACKGROUND: The occurrence of vascular stiffness in the setting of the nephrotic syndrome and the influence of serum phosphate on this association is unknown. METHODS: A retrospective study of 42 prevalent, adult nephrotic patients who underwent carotid-femoral pulse wave velocity (PWV) measurement, a median of 24 months after kidney biopsy. Elevated PWV was determined using published age-specific reference ranges. The association, statistical significance and independence of serum phosphate with spot urine protein-creatinine ratio (PCR) and the association of phosphate with PWV was examined. RESULTS: Mean PCR was 5.5 g/g and mean eGFR (CKD-EPI) was 70 mL/min/1.73 m2. Serum phosphate was statistically significantly associated with severity of nephrotic syndrome independently of eGFR and age. Median (intra-quartile range) PWV was 7 m/s (4-11), with a linear trend for higher PWV across tertile of average serum phosphate over follow-up, P<.001. Twenty subjects (48%) had elevated age-specific PWV, which on logistic regression was statistically significantly associated with mean serum phosphate, OR (95% CI) per 0.1 mmol/L: 2.7 (1.5, 4.9), P = .001, which in separate analyses was independent of eGFR and other laboratory data. CONCLUSIONS: In this cohort of patients with the nephrotic syndrome serum phosphate was commonly elevated, despite well preserved eGFR, which was significantly and independently associated with elevated PWV over follow-up.

In-office assessment of blood pressure in chronic kidney disease: usual measurement versus automated BpTRU measurement.

OBJECTIVES: The automated BpTRU device has been shown to improve the accuracy of in-office blood pressure assessment in hypertensive populations. We aimed to determine whether this was also true for patients with chronic kidney disease. MATERIALS AND METHODS: We recorded the blood pressure of 80 hypertensive outpatients with chronic kidney disease by usual automated measurement and BpTRU automated measurement. We established whether there were any statistically significant differences in the absolute blood pressure values measured by either method and whether these differences had any impact on the assessment of blood pressure control. RESULTS: Systolic and diastolic blood pressures were significantly lower by BpTRU measurement than by usual measurement, by 10.1±12.2 mmHg (95% confidence interval: 7.4-12.8 mmHg, P<0.001) and 2.8±10.6 mmHg (95% confidence interval: 0.4-5.1 mmHg, P=0.02), respectively. Significantly, more patients achieved their blood pressure target of 130/80 mmHg or less by BpTRU measurement than by usual measurement (72.5 vs. 48.8% for systolic blood pressure, P<0.001; 68.8 vs. 61.3% for diastolic blood pressure, P=0.02). Systolic blood pressures remained significantly lower by BpTRU measurement than by usual measurement in all predefined study subgroups (estimated glomerular filtration rate <30 vs ≥30 ml/min/1.73m; transplant vs. nontransplant). We detected more hypotension by BpTRU measurement than by usual measurement. CONCLUSION: Our study suggests that the BpTRU device can negate white coat effect in patients with chronic kidney disease. The use of this device in routine clinical practice could improve the overall accuracy of in-office blood pressure assessment in this high-risk population, minimizing the potential for undertreatment and overtreatment of hypertension.

Maintenance hemodialysis patients have high cumulative radiation exposure.

Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number and type of radiological procedures were obtained from a central radiology database, and the cumulative effective radiation dose was calculated using standardized, procedure-specific radiation levels. The median annual radiation dose was 6.9 millisieverts (mSv) per patient-year. However, 14 patients had an annual cumulative effective radiation dose over 20 mSv, the upper averaged annual limit for occupational exposure. The median total cumulative effective radiation dose per patient over the study period was 21.7 mSv, in which 13 patients had a total cumulative effective radiation dose over 75 mSv, a value reported to be associated with a 7% increased risk of cancer-related mortality. Two-thirds of the total cumulative effective radiation dose was due to CT scanning. The average radiation exposure was significantly associated with the cause of end-stage renal disease, history of ischemic heart disease, transplant waitlist status, number of in-patient hospital days over follow-up, and death during the study period. These results highlight the substantial exposure to ionizing radiation in hemodialysis patients.