The Kidney Disease Outcomes and Quality Initiative (K/DOQI) guidelines call for a significant increase in the use of natural vein fistulas. Long-term tunneled dialysis catheters (LTTDCs) will have an important role in facilitating the maturation of natural vein fistulas. LTTDCs also functions as the access of last resort in patients who refuse or have exhausted other forms of permanent vascular access. This article, which is based on the authors' experience as interventional nephrologists, discusses factors influencing catheter function. In addition, the article reviews common complications associated with dialysis catheter insertion, including immediate, short-term, and long-term complications. The topics reviewed include stenoses, thrombus formation, fibrin sheath formation, infections, and vascular ingrowth. Suggestions for management are also discussed.

Secondary hyperparathyroidism is associated with progressive bone loss. Suppression of plasma iPTH with cinacalcet appears to reverse bone loss in the proximal femur, but does not affect BMD of the lumbar spine. A larger study is warranted to confirm that cinacalcet has a beneficial effect on the skeletal system in patients with secondary hyperparathyroidism.

Blood pressure (BP) has a circadian pattern with a 10% to 15% drop in systolic and diastolic BP comparing nighttime and daytime averages. The mechanism and the "reason" for the decline of nocturnal blood pressure has not been described. If the nocturnal decline is a restorative physiologic process we reasoned that sleep deprivation would increase the nocturnal drop. Thus, we tested the hypothesis that there is a compensatory decline in nocturnal sleep blood pressure after a period of nocturnal sleep deprivation. Twenty-four house staff personnel (normotensive and not taking any BP medications) with a mean age of 29.3 years were recruited for this study (13 men and 11 women). Subjects were randomly assigned to have 24-h BP monitoring after being sleep deprived (on call with 3 +/- 1.3 h of sleep) or after a normal night's sleep (7.3 +/- 0.8 h). There was no significant difference in hours asleep or time to bed or time awake for both 24-h studies. Subjects had similar activities for both monitoring intervals. The percent change in day awake versus night asleep mean values for systolic BP, diastolic BP, and mean arterial pressure for sleep deprived and normal night's sleep intervals were compared using paired t tests. None of these paired parameters were significantly different despite a subjectively "deeper" sleep postcall. In conclusion, sleep deprivation does not appear to result in a compensatory decline in nocturnal blood pressure. Thus, the "reason" for the normal nocturnal decline in blood pressure remains to be explored.

In published studies of chronic haemodialysis patients, the frequency of autonomic dysfunction varies widely. One reason for the variation may be the time of testing with respect to time of dialysis. The current study tests the hypothesis that autonomic function--as measured by heart rate responses to the Valsalva manoeuvre (Valsalva ratio) and 30:15 electrocardiogram (ECG) R-R interval to upright posture (postural ratio)--is different when patients are above 'dry weight' (predialysis) than when they are at or below dry weight (postdialysis). The study also reviews available literature to analyze other factors that may affect the results of autonomic testing in this population. A total of 25 chronic haemodialysis patients underwent standard Valsalva and 30:15 R-R interval postural autonomic testing prior to and after haemodialysis. In addition, pre- and postdialysis orthostatic responses were measured and compared with a control population. The 30:15 ratio increased after dialysis (p = 0.001). The Valsalva ratio did not change with dialysis. Out of 25 subjects, seven had an abnormal 30:15 ratio prior to dialysis decreasing to two out of 25 patients postdialysis (p < 0.03). Orthostatic responses predialysis did not differ from those in the control group. Review of the literature shows great variability in definition of normal Valsalva and postural (30:15 R-R interval) ratios. Diabetic patients in the current and prior studies were more likely to have abnormal responses.(ABSTRACT TRUNCATED AT 250 WORDS)