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.     

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.     

Can We Create an Arteriovenous Fistula for Hemodialysis through 0.5–1.0 cm Incision without Using Vascular Clamps?

Background A native arteriovenous fistula (AVF) is a gold standard for renal replacement therapy, where regular hemodialysis is the mainstay of survival in the majority of patients suffering from end-stage renal disease. Appropriate vascular clamps are routinely used to occlude an artery and a vein before an arteriotomy or a venotomy is done to prevent blood loss and have a clear field and an ease of anastomosis. The title makes one wonder, is it then possible to create an AVF without using vascular clamps? And through incisions as small as 0.5to 1.0 cm? This is made possible by a very simple new technique, presented here, that helps to occlude vessels to create an AVF through minimal access, and minimize blood loss and postoperative pain. Material and Method  Total 622 AVFs were created between 1998 and 2019. With regular forceps or an AVF platform (design given), an AVF was created without using a vascular clamp. Total 321 cases were operated with 0.5 to 1.0 cm and 215 cases within 1.5 cm skin incision approach. Results  There were ~85% successful functional fistulas. The blood loss was negligible, and only one in three required pain killer in postoperative period. Conclusion  A simple new technique described here makes it possible to create a functional AVF through a small incision, without using vascular clamps.     

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.     

An “All-Comers” Venous Duplex Scan Policy for Patients with Lower Limb Varicose Veins Attending a One-stop Vascular Clinic: Is It Justified?

OBJECTIVE: To determine whether clinical assessment could predict the correct management of patients with varicose veins (VVs), select those who would need duplex scanning, and identify deep venous reflux (DVR). METHODS: Prospective study of 342 consecutive limbs with VVs. These were divided into 3 groups: 170 (50%) limbs with primary VVs without skin changes (group I), 37 (11%) with recurrent VVs without skin changes (group II), and 135 (39%) with primary or recurrent VVs with skin changes (group III). Clinicians were asked to document whether they would normally request a duplex scan because of clinical uncertainty. Agreement between decision-making based on clinical and on duplex findings was documented. RESULTS: Agreement between clinical and duplex findings for groups I, II, and III was 82%, 59%, and 67%, respectively. In 112 cases (66%) in group I, clinicians felt certain about the diagnosis and yet duplex scanning revealed they were wrong in 12% of cases. In group II, clinicians would request a duplex scan because of clinical uncertainty in 30 (81%) cases. In group III, the sensitivity, specificity, positive and negative predictive value of clinical assessment in detecting DVR was 32%, 77%, 24%, and 83%, respectively. CONCLUSIONS: Clinical evaluation of patients with VVs is unreliable in planning their management. Clinicians can neither predict those who will require duplex scanning nor correctly identify DVR. Even experienced surgeons often "get it wrong" when assessing primary uncomplicated veins despite being certain about the diagnosis. Therefore, an "all-comers" duplex imaging policy should be implemented if optimal management is to be achieved.     

“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.