A new safety device for hemodialysis.

Accidental venous needle dislodgement during hemodialysis may cause serious bleeding including a sometimes fatal outcome. The venous pressure gauge of the dialysis monitor does not react when dislodgement occurs. A sensor patch put as an adhesive over the venous needle puncture site connected to an alarm unit by an optic fiber has been clinically tested in 5 dialysis departments. A small amount of blood on the sensor activates a light and sound alarm. A simple questionnaire was filled out by the nurses at each dialysis concerning their feeling of safety when the new device was used. Forty-one patients, mean age 65 years, have tested the new safety device. Two hundred test dialyses were studied, after exclusion of 13 tests. One hundred seventy-nine tests reacted positively on blood. In another 6 dialyses, a warning light appeared on the alarm unit indicating a failure in the sensor patch. Thus, the alarm functioned in 92.5% of all tests. After a small modification of the sensor patches there were only 2 dialyses (2/71) without an activated alarm on blood, i.e., 97.2% positive alarm reactions. The answers of the nurses indicated that they had an increased feeling of safety when using the new safety device, with a mean value of 3.4 points on a visual scale from 0 to 5 where 5 meant very much increased safety. In a situation when the dialysis monitors today do not react on bleedings from venous needle dislodgements, the new alarm safety device fulfils a known shortage in routine dialysis safety. In situations where supervision during a dialysis session may be insufficient as, for example, in home hemodialysis and self-care dialysis or in other situations when the patient is sleeping, the device may be life saving.

Baroreflex effectiveness index and baroreflex sensitivity predict all-cause mortality and sudden death in hypertensive patients with chronic renal failure.

OBJECTIVES: Impaired arterial baroreflex sensitivity (BRS) has been associated with cardiac mortality and non-fatal cardiac arrests after a myocardial infarction. Patients with chronic renal failure (CRF) have a poor prognosis because of cardiovascular diseases, and sudden death is common. The aim of this study was to assess whether BRS or the baroreflex effectiveness index (BEI), a novel index reflecting the number of times the baroreflex is active in controlling the heart rate in response to blood pressure fluctuations, is associated with prognosis in CRF. METHODS: Hypertensive patients with CRF who were treated conservatively, by haemodialysis or peritoneal dialysis were studied. Electrocardiogram and beat-to-beat blood pressures were recorded continuously and BRS and BEI were calculated. Patients were then followed prospectively for 41 +/- 15 months (range 1-64). RESULTS: During follow-up 69 patients died. Cardiovascular diseases and uraemia accounted for the majority of deaths (60 and 20%, respectively), whereas sudden death occurred in 15 patients. In adjunct with established risk factors such as age, diabetes, congestive heart failure and diastolic blood pressure, reduced BEI was an independent predictor of all-cause mortality among CRF patients [relative risk (RR) 0.50, 95% confidence interval (CI) 0.33-0.71 for an increase of one standard deviation in BEI, P < 0.001]. Diabetes and reduced BRS were independent predictors of sudden death (RR 0.29, 95% CI 0.09-0.86 for an increase of one standard deviation in BRS, P=0.022). CONCLUSIONS: Both BEI and BRS convey prognostic information that may have clinical implications for patients with cardiovascular diseases in general.

Reduced baroreflex effectiveness index in hypertensive patients with chronic renal failure.

BACKGROUND: Impaired arterial baroreflex function has been associated with an increased risk of ventricular arrhythmia and sudden death. This has also been suggested for patients with chronic renal failure (CRF) who are at high risk for cardiovascular morbidity. The aim of this study was to investigate the arterial baroreflex function in CRF patients with emphasis on analyzing the time during which the arterial baroreflex is active, the baroreflex effectiveness index (BEI). METHODS: Beat-to-beat blood pressure (measured with Portapres) and electrocardiography were continuously registered during 30 min rest in 216 hypertensive CRF patients on hemodialysis (n=95), continuous ambulatory peritoneal dialysis (n=59), or conservative treatment (n=59). The spontaneous sequence method was used to calculate BRS and BEI. Age-matched healthy subjects (n=43) were examined for comparison. RESULTS: The BRS was reduced by 51% and the BEI by 49% in CRF patients compared with healthy subjects (P<.001 for both). In addition, CRF patients with diabetes showed further reductions compared with patients without diabetes (15% reduction of BRS and 44% of BEI, P<.01 for both). The treatment modality for renal failure had no effect on BRS or BEI. In a multivariate linear regression analysis, age, body mass index, and systolic blood pressure were independent predictors of BRS, whereas age and diabetes were independent predictors of BEI in patients with CRF. CONCLUSIONS: We conclude that BEI, which is markedly reduced in hypertensive patients with CRF, may convey information on arterial baroreflex function that is complementary to BRS.

Elevated temporal QT variability index in patients with chronic renal failure.

Patients with CRF (chronic renal failure) are at increased risk of cardiovascular diseases, and 60% of cardiovascular mortality in CRF is attributed to sudden death. Various abnormalities in myocardial repolarization are associated with the risk of ventricular arrhythmia. The aim of this study was to evaluate an index of temporal myocardial repolarization lability, the temporal QTVI (QT variability index), in patients with CRF. ECGs were recorded in 153 patients with CRF on haemodialysis (n=67), continuous ambulatory peritoneal dialysis (n=43) or conservative treatment (n=43) during 30 min of rest. QTVI was calculated as the logarithm of the ratio between the variances of the normalized QT and RR intervals. Age-matched healthy subjects (n=39) were examined for comparison. QTVI was increased by 47% in CRF patients compared with healthy subjects (-0.82+/-0.56 compared with -1.54+/-0.27 respectively; P<0.01). QTVI did not differ among patients on dialysis or conservative treatment, whereas QTVI was elevated further in patients with diabetes compared with non-diabetic CRF patients (-0.56+/-0.54 compared with -0.94+/-0.52 respectively; P<0.01). In a multiple linear regression analysis, diabetes and a history of coronary artery disease were the only independent predictors of QTVI in the CRF population. The present study demonstrates that elevated QTVI in patients with CRF is associated with diabetes and coronary disease. The present findings are important given that repolarization instability may predispose to ventricular arrhythmia and sudden death, events that occur frequently in CRF patients.

A randomized controlled trial of haemoglobin normalization with epoetin alfa in pre-dialysis and dialysis patients.

BACKGROUND: Partial correction of renal anaemia with erythropoietin improves quality of life (QoL). We aimed to examine if normalization of haemoglobin with epoetin alfa in pre-dialysis and dialysis patients further improves QoL and is safe. METHODS: 416 Scandinavian patients with renal anaemia [pre-dialysis, haemodialysis (HD) and peritoneal dialysis patients] were randomized to reach a normal haemoglobin of 135-160 g/l (n=216) or a subnormal haemoglobin of 90-120 g/l (n=200) with or without epoetin alfa. Study duration was 48-76 weeks. QoL was measured using Kidney Disease Questionnaires in 253 Swedish dialysis patients. Safety was examined in all patients. RESULTS: QoL improved, measured as a decrease in physical symptoms (P=0.02), fatigue (P=0.05), depression (P=0.01) and frustration (P=0.05) in the Swedish dialysis patients when haemoglobin was normalized. In pre-dialysis patients, diastolic blood pressure was higher in the normal compared with the subnormal haemoglobin group after 48 weeks. However, the progression rate of chronic renal failure was comparable. In the normal haemoglobin group (N-Hb), 51% had at least one serious adverse event compared with 49% in the subnormal haemoglobin group (S-Hb) (P=0.32). The incidence of thrombovascular events and vascular access thrombosis in HD patients did not differ. The mortality rate was 13.4% in the N-Hb group and 13.5% in the S-Hb group (P=0.98). Mortality decreased with increasing mean haemoglobin in both groups. CONCLUSIONS: Normalization of haemoglobin improved QoL in the subgroup of dialysis patients, appears to be safe and can be considered in many patients with end-stage renal disease.