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.     

“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.     

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.     

Should We Give Prophylactic “Renal‐Dose” Dopamine After Coronary Artery Bypass Surgery?

OBJECTIVE: A prospective double-blind randomized study undertaken to assess the effect of postoperative prophylactic "renal-dose" dopamine on post-coronary artery bypass grafting surgery's clinical outcome. METHODS: Eighty-five consecutive patients undergoing CABG operation were randomized to receive either 3-5 microg/kg/min dopamine (group D, n = 41) or saline as placebo (group P, n = 45) for 48 postoperative hours. Clinical outcome parameters were collected for four postoperative days. RESULTS: Preoperative and operative parameters were similar in both groups. Four patients from group P and none from group D reached an end-point of the study (oliguria, renal dysfunction) and received dopamine. Two patients from group P and none from group D needed an additional inotropic support. Mean arterial pressure values were similar during the first 24 hours after operation, but left atrial pressure values tended to be higher in group P (10 +/- 4 vs 7 +/- 3 mmH2O, p = 0.18). The mean pH was higher in group D at 8 hours after operation (7.38 +/- 0.2 vs 7.36 +/- 0.3, p = NS), due to higher bicarbonate levels (23 +/- 2 mmol/l vs 21 +/- 2, p = 0.49). The incidence of lung congestion in chest X-rays and CT scans was significantly higher in group P (50% vs 29%, p = 0.073 at 48 hours postoperatively). Room air blood O2 saturation and maximal expiratory volume tended to be higher in group D (at 72 hours after operation- 92 +/- 4 vs 90%+/- 5, p = 0.29 and 646 +/- 276 vs 485 ml +/- 206, p = 0.16, respectively). There was no statistical difference in urine output but the amount of furosemide given to patients in group P was significantly higher (during the first 8 hours 2.5 +/- 0.5 vs. 0.3 mg +/- 1.6, p = 0.07). Plasma creatinine levels were significantly lower in group D (at 24 hours 0.93 +/- 0.02 vs 1.05 mg/dL +/- 0.02, p = 0.02). Mobilization after surgery was faster in group D. CONCLUSIONS: Prophylactic dopamine administration after coronary artery bypass grafting surgery improves patient hemodynamic and renal status, reduces the need for additional medical support (inotropes and furosemide) and thus, provides stable postoperative course.     

CARDIOVASCULAR AND SURVIVAL PARADOXES IN DIALYSIS PATIENTS: Body Mass Index and Peritoneal Dialysis: “Exceptions to the Exception” in Reverse Epidemiology?

Until recently, it was not apparent whether apparent paradoxical associations of body mass index (BMI), lipids, and blood pressure with survival observed in hemodialysis (HD) patients, which contradict observations from the general population, also applied to peritoneal dialysis (PD) patients. Studies of survival in PD patients must account for differences in adjusted survival relative to HD patients, namely, early equivalent to superior survival, but after about 1-2 years, inferior survival. Several recent observational studies have analyzed the association between BMI and survival in PD patients from different perspectives and using different patient populations. In general, these studies found that any survival advantage associated with obesity is significantly less likely in PD than HD patients. Among PD patients, those who are obese can be said to have equivalent survival to PD patients with normal BMI. Studies of lipids and blood pressure in PD patients also yield conflicting associations with survival. Obese patients, especially if diabetic, may have increased risk of death after starting on PD compared to HD, although firm conclusions are premature given the limitations of current evidence. At present, the levels of lipids and blood pressure which are best associated with survival in PD patients are not well-defined.     

Ethical Issues in Dialysis: Institutionalized Racism and End‐Stage Renal Disease: Is Its Impact Real or Illusionary?

Racism is the subjugation of one group (superior) over another (inferior) and may be divided into two categories: overt (gross) and covert. Covert racism (subconscious) is categorized as institutionalized racism. Although institutionalized racism is a more tolerant and restrained practice of this superior/inferior ethnic construct in which African Americans or other people of color are treated as inferiors, it has led to important health disparities between blacks and whites. One area where its mark is most indelible is in the treatment of end-stage renal disease (ESRD).     

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.