A B S T R A C T Using radioactive xenon, we measured the regional distribution of pulmonary ventilation and blood flow in six normal men, whose ages ranged between 65 and 75 yr. The measurements were made in the standing position. The static volume-pressure relation of the lungs was also measured in five of the subjects. The results indicate that by comparison with normal young men: (a) Blood flow to the upper lung zones was increased, although it still remained predominant in the lower zones. (b) Ventilation distribution during a vital capacity inspiration was similar to that seen in young subjects. (c) In five of the six elderly subjects, however, the distribution of ventilation in the resting tidal volume range was not preferential to the lower zones as it was in young men. This was probably caused by airway closure in the lower lung zones. The elderly subjects thus exhibit during normal tidal volume breathing a ventilation distribution pattern similar to that observed in young subjects when breathing at low lung volumes, i.e., near residual volume. This difference is probably due to the combined effect of the loss in elastic recoil of the lungs observed in the elderly subjects and of a decreased resistance to collapse of the aged airways. These findings suggest that in the elderly subjects there is a significant regional ventilation-perfusion impairment during quiet breathing, which may explain in part Dr. Holland's present address is Cardio-Pulmonary Laboratory, Dalhousie University, Halifax, Canada. Address requests for reprints to Dr.

This article describes cannulation events, especially problems, common and rare, minor and major, to aid the nephrologist (and mid-level providers e.g. nurse practitioner and physician's assistant) in decision-making to prevent or treat cannulation-related adverse outcomes. The usual management, potential outcomes, nephrologist intervention, and prevention are discussed and include: assessment of arteriovenous (AV) access and readiness for cannulation; initial cannulation of both arteriovenous fistulas and grafts; needle size and adequacy; needle direction and potential for recirculation; limited cannulation sites/buttonhole; pain and fear of pain; prevention of bleeding; management of infiltrations/extravasations; prevention and management of "one-site-itis"; prevention and management of infection. It concludes with the importance of the medical director as the leader of the continuous quality improvement (CQI) team in preventing/reducing cannulation-related adverse events.

SIAPR does not correlate with Qa or discriminate between high and low Qa. Therefore, because the utility of SIAPR surveillance for detection of clinically significant stenosis depends on a correlation with Qa, the current use of absolute K/DOQI SIAPR thresholds for intervention based on the presumption that such thresholds are indicative of low Qa is not justified, and should be discontinued. Studies need to be done to examine the utility of SIAPR for trend analysis.

Hemodialysis patients using central venous catheters (CVCs) for vascular access are at greater risk of infection and death vs. arterial venous fistula (AVF). In 2008, DaVita initiated the CathAway quality improvement initiative, a multidisciplinary program to reduce CVC use in favor of AVF. Our retrospective analysis examined CVC use for incident (≤90 days) and prevalent (>90 days) patients receiving hemodialysis in the years 2006 to 2010. Outcomes included annual mean percentage of patients with CVCs, new CVC placements per 100 patient years, CVC survival, and percentage patient days with CVC. Over 152,000 patient records were reviewed. Between 76.2% and 79.7% of incident patients used a CVC annually, but for prevalent patients, the proportion decreased from 41.1% in 2006 to 33.5% in 2010. The number of new CVC placements per 100 patient years increased slightly for incident patients but fell annually from 64.8 in 2006 to 55.2 in 2010 for prevalent patients. The percentage of treatment days with CVCs was stable among incident patients (70.4%-74.3%) but fell among prevalent patients from 26.1% in 2006 to 16.5% in 2010. The mean duration of CVC use in incident patients was between 53.0 days (SD, 27.8) in 2006 and 54.1 days (SD, 28.1) in 2009, and for prevalent patients between 158.9 days (SD, 123.0) in 2006 and 128.1 days (SD, 112.0) in 2010. CathAway significantly decreased CVC use in prevalent hemodialysis patients. Decreasing incident patient use will require improvements in predialysis care.

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