Flow measurements: Can several “Wrongs” make a “Right”?

AIMS: Although measurement of maximum flow rate (Qmax) is a standard and straightforward test, it is often difficult to obtain reliable readings. We obtained multiple measurements using a simple home uroflow device which categorizes Qmax into ranges. We hypothesize that the average of a series of relatively coarse measurements of Qmax would be more repeatable and therefore more representative of an individual's voiding function than a single, albeit more precise measurement. METHODS: We studied 22 male volunteers with a wide range of Qmax. They were asked to record flow category (<10 ml/sec; 10-15 ml/sec; 15-20 ml/sec; >20 ml/sec) and voided volume twice daily for 12 days using the home flow device. In addition, a clinic-based flow recording using a spinning-disc uroflowmeter was obtained at both the start and the end of the 12-day period. RESULTS: Good agreement between mean home flow and mean clinic flow was seen with mean (SD) difference of 1.3 (5) ml/sec. The mean for consecutive halves of an individual's home flow data showed excellent agreement (-0.2 (1.3) ml/sec). The two clinic readings showed poorer agreement (2.3 (6.8) ml/sec) than the home readings, and poorer agreement even than between clinic and home flows. CONCLUSIONS: Although simple in design, the home flowmeter actually shows greater accuracy than might be expected when used repeatedly to study the flow rates of men. Simple flow devices such as this could be used in conjunction with voiding diaries to give a more representative picture of patients' day-to-day voiding function.     

Central venous catheters for chronic hemodialysis: Is “last choice” never the “right choice”?

Since the publication of the first vascular access clinical practice guidelines in 1997, the global nephrology community has dedicated significant time and resources toward increasing the prevalence of arteriovenous fistulas and decreasing the prevalence of central venous catheters for hemodialysis. These efforts have been bolstered by observational studies showing an association between catheter use and increased patient morbidity and mortality. To date, however, no randomized comparisons of the outcomes of different forms of vascular access have been conducted. There is mounting evidence that much of the difference in patient outcomes may be explained by patient factors, rather than choice of vascular access. Some have called into question the appropriateness of fistula creation for certain patient populations, such as those with limited life expectancy and those at high risk of fistula‐related complications. In this review, we explore the extent to which catheters and fistulas exhibit the characteristics of the “ideal” vascular access and highlight the significant knowledge gaps that exist in the current literature. Further studies, ideally randomized comparisons of different forms of vascular access, are required to better inform shared decision making.     

Can Change in FRAX Score Be Used to “Treat to Target”? A Population‐Based Cohort Study

It is unknown how responsive the Fracture Risk Assessment (FRAX) tool is to osteoporosis treatment (OTX) or whether it can serve as a target for “goal‐directed” treatment. We studied 11,049 untreated women aged ≥50 years undergoing baseline and follow‐up DXA examinations in Manitoba, Canada. We identified clinical risk factors, intervening OTX based on medication possession ratios (MPR), and incident fractures. FRAX scores for major osteoporotic and hip fractures were computed for each scan using the most current (updated) FRAX inputs. Over 4 years, median FRAX scores showed an increase of 1.1% for major fractures and 0.3% for hip fractures, including women highly adherent to OTX (0.6% and 0.1% increases). Few (2.2%) highly adherent women had a decrease in major fracture probability exceeding 4%, whereas 9.0% had a decrease in hip fracture probability exceeding 1%. Compared with untreated women, OTX was associated with a higher dose‐dependent likelihood of attenuating the expected increase in major fracture risk: adjusted odds ratios (aOR) 2.3 (95% confidence interval [CI] 1.8–2.9) for MPR <0.50; 7.3 (95% CI 5.6–9.6) for MPR 0.50–0.79; and 12.0 (95% CI 9.5–15.2) for MPR ≥0.80. In the 4 years after the second DXA scan, 620 (6%) women had major fractures (152 hip fractures). FRAX scores were strongly predictive of incident major fractures (adjusted hazard ratios [aHR] per SD increase in FRAX 1.8, 95% CI 1.7–1.9) and hip fractures (aHR per SD 4.5, 95% CI 3.7–5.7); however, change in FRAX score was not independently associated with major fracture (p = 0.8) or hip fracture (p = 0.3). In conclusion, FRAX scores slowly increased over time, and this increase was attenuated but not prevented by treatment. Few women had meaningful reductions in FRAX scores, and change in FRAX score did not independently predict incident fracture, suggesting that FRAX with BMD is not responsive enough to be used as a target for goal‐directed treatment. © 2014 American Society for Bone and Mineral Research.     

Use of SARS‐CoV‐2‐infected deceased organ donors: Should we always “just say no?”

In the context of a rapidly evolving pandemic, multiple organizations have released guidelines stating that all organs from potential deceased donors with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection should be deferred, including from otherwise medically eligible donors found to have mild or asymptomatic SARS‐CoV‐2 discovered on routine donor screening. In this article, we critically examine the available data on the risk of transmission of SARS‐CoV‐2 through organ transplantation. The isolation of SARS‐CoV‐2 from nonlung clinical specimens, the detection of SARS‐CoV‐2 in autopsy specimens, previous experience with the related coronaviruses SARS‐CoV and MERS‐CoV, and the vast experience with other common RNA respiratory viruses are all addressed. Taken together, these data provide little evidence to suggest the presence of intact transmissible SARS‐CoV in organs that can potentially be transplanted, specifically liver and heart. Other considerations including ethical, financial, societal, and logistical concerns are also addressed. We conclude that, for selected patients with high waitlist mortality, transplant programs should consider accepting heart or liver transplants from deceased donors with SARS‐CoV‐2 infection.     

“Turn downs” in aortic emergencies: Reassurance or uncertainty?

“Turn‐down” rate has been reported to have a significant influence on outcomes, and being turned down for an operation is associated with significant short‐term mortality risk. A study examining the impact of the pandemic on the “turn‐down” rates of acute aortic syndromes in the United Kingdom reported an overall “turn‐down” rate of  7.3% in the early part of the pandemic. This review examines the significance of “turn‐downs” in this setting and scrutinizes the adequacy of reporting this complex variable.     

Rotary Blood Pumps for Cardiac Assistance: A “Must”?

Ventricular Assist Devices (VADs) were developed following the observation that most end-stage heart failure patients only required left heart support for survival. The trend toward left VAD implantation instead of a TAH has actually contributed to the development of nonpulsatile rotational devices. This article intends to evaluate the current and future technology of continuous flow pumps. Various issues pertaining to the long-term effects of continuous blood flow, biocompatibility of axial flow pumps, and the safety and reliability of such devices need to be addressed. Some of the advantages of rotary blood pumps include their small size, ease of implantation, and encouraging low infection rates. Certain issues such as automatic flow control, device components durability, and hemocompatibility remain unresolved. The quest for an ideal device combining optimal efficiency, ease of anatomical fit, and perfect bioacceptance, continues. Rotary blood pumps are not yet a "must."     

Intensive Hemodialysis: Normalizing the “Unphysiology” of Conventional Hemodialysis?

Interest in intensified hemodialysis (HD) regimens is increasing internationally, as there is growing evidence that they are associated with improved outcomes. Appreciation that conventional hemodialysis (CHD), delivered as 4-hour sessions three times a week, is not providing optimal physiological replacement of renal function has led to the development of intensified dialysis therapies. These include long intermittent hemodialysis typically lasting 6-8 hours and delivered three times a week, short daily hemodialysis, providing more frequent sessions 4-7 days a week lasting 2-3.5 hours, and nocturnal hemodialysis, performed 5-7 days a week for 6-8 hours. Studies evaluating outcomes from these programs have indicated superior results to those achieved with CHD, including favorable modifications of cardiovascular risk factors and improvements in a variety of clinical measures. The objective of this review is to present available evidence supporting the hypothesis that in an attempt to provide a "more normal physiology," intensified HD regimens achieve outcomes superior to those historically achieved with CHD.