Predicting arterio-venous fistula failure by urea–method derived access blood flow in chronic hemodialysis patients

2020 ◽  
Vol 21 (6) ◽  
pp. 1011-1016
Author(s):  
Kumtorn Lelamali ◽  
Piyarek Papirachanat ◽  
Thitiya Puavilai

Background: Dialysis access is an essential part of hemodialysis. Determining the access blood flow (Qa) can help predict arterio-venous fistula thrombosis. Qa determination by the urea method, which was previously described in the past is simple and is available in most of the dialysis units but was not be able to predict arterio-venous fistula thrombosis. Aim: To compare the efficacy of Qa determination by the urea method and by ultrasound dilution methods in predicting arterio-venous fistula failure. Methods: Qa was measured by urea method and by ultrasound dilution simultaneously, every 3 months for a period of 1 year, in stable chronic hemodialysis patients with arterio-venous fistula. Arterio-venous fistula failure determined by clinical parameters and confirmed by Doppler ultrasound before sending the patient for interventional angioplasty. Results: This study enrolled a total of 16 patients, with 63% being male, 75% with lower-arm arterio-venous fistula and around 43% with previously done angioplasty. 59-Qa measurements were done, and 6 patients underwent angioplasty (one patient for severe upper limb edema, one for access thrombosis, and four for access dysfunction). Qa determination by the urea method had non-significantly lower Qa, (745 mL/min (interquartile range: 509–1143) and 779 mL/min (interquartile range: 530–1160), (p = 0.58)) and high correlation (r = 0.83, p < 0.001) to Qa by ultrasound dilution. The cut-off criteria with its sensitivity and specificity in predicting the access failure were 440 mL/min, 66.67%, and 96.15% for Qa determination by the urea and 400 mL/min, 66.67% and 90.38% for Qa by ultrasound dilution, respectively, with no difference in the area under the receiver operating characteristic curve. Conclusion: Measurement of Qa determination by the urea method is well correlated with Qa by ultrasound dilution and can be used to predict vascular access failure.

2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Romain Vial ◽  
Marion Gully ◽  
Mickael Bobot ◽  
Violaine Scarfoglière ◽  
Philippe Brunet ◽  
...  

Background: Daily management to shield chronic dialysis patients from SARS-CoV-2 contamination makes patient care cumbersome. There are no screening methods to date and a molecular biology platform is essential to perform RT-PCR for SARS-CoV-2; however, accessibility remains poor. Our goal was to assess whether the tools routinely used to monitor our hemodialysis patients could represent reliable and quickly accessible diagnostic indicators to improve the management of our hemodialysis patients in this pandemic environment. Methods: In this prospective observational diagnostic study, we recruited patients from La Conception hospital. Patients were eligible for inclusion if suspected of SARS-CoV-2 infection when arriving at our center for a dialysis session between March 12th and April 24th 2020. They were included if both RT-PCR result for SARS-CoV-2 and cell blood count on the day that infection was suspected were available. We calculated the area under the curve (AUC) of the receiver operating characteristic curve. Results: 37 patients were included in the final analysis, of which 16 (43.2%) were COVID-19 positive. For the day of suspected COVID-19, total leukocytes were significantly lower in the COVID-19 positive group (4.1 vs. 7.4 G/L, p = 0.0072) and were characterized by lower neutrophils (2.7 vs. 5.1 G/L, p = 0.021) and eosinophils (0.01 vs. 0.15 G/L, p = 0.0003). Eosinophil count below 0.045 G/L identified SARS-CoV-2 infection with AUC of 0.9 [95% CI 0.81—1] (p < 0.0001), sensitivity of 82%, specificity of 86%, a positive predictive value of 82%, a negative predictive value of 86% and a likelihood ratio of 6.04. Conclusions: Eosinophil count enables rapid routine screening of symptomatic chronic hemodialysis patients suspected of being COVID-19 within a range of low or high probability.


2003 ◽  
Vol 4 (2) ◽  
pp. 39-44 ◽  
Author(s):  
M. Leblanc ◽  
E. Saint-Sauveur ◽  
V. Pichette

Native arterio-venous fistulas (AVFs) are preferred for hemodialysis vascular access over synthetic grafts and long-term catheters. However, prevalence rates of native AVFs are variable around the world and have increased only slightly in United States since the DOQI guidelines. To increase rates of native AVFs, pre-operative vascular mapping by ultrasound has been found of major help for appropriate selection of the vessels. The minimal desirable lumen diameter of the artery should be > 2 mm and > 2.5 to 3 mm for the vein at the anatomosis. Early failure can be reduced to less than 10% when the feeding artery is > 2 mm, even in diabetics. If sizes of the vessels are smaller than those targets at the wrist, moving to the upper arm should be considered. The interval between creation and first cannulation varies from 2 weeks to 4 months. There might not be much advantage to wait for more than 4 weeks; however, in large dialysis units, observing a delay of 4 to 6 weeks may be worthwhile to avoid initial problems such as infiltrations and lacerations. Access flow monitoring is essential since it is a reliable predictor of vascular access dysfunction, reducing associated morbidity and costs. Early monitoring of recently created native AVFs has shown that the increase in intra-access blood flow occurs very soon after construction and becomes maximal after a few weeks. A recent prospective study involving all new native AVFs monitored by ultrasound-dilution between weeks 6 and 10 after creation, and every 3 to 6 weeks over 4 months, showed no statistically significant difference in access blood flow between the initial and final measurements (respective values of 1132 ± 681 and 1097 ± 644 ml/min). Access flow was higher in males, and in brachio-cephalic compared to radio-cephalic AVFs. Over the long-term, AVFs are associated with longer patency and lower complication rates, and efforts should be directed at further increasing their prevalence.


1989 ◽  
Vol 37 (4) ◽  
pp. 1519-1522
Author(s):  
Kazunori Matsushita ◽  
Toshiyuki Tsuruta ◽  
Ryuji Kitajima ◽  
Toshinori Nakao ◽  
Tomoyuki Honda ◽  
...  

1988 ◽  
Vol 11 (1) ◽  
pp. 45-50 ◽  
Author(s):  
F.G. Heineken ◽  
M. Brady-Smith ◽  
J. Haynie ◽  
J.C. Van Stone

A rearranged equation of Sargent and Gotch (1) was used to determine dialysate bicarbonate concentrations for hemodialysis patients. Parameters in this equation include an estimate of the acid generated by each patient between treatments, an estimate for the dialyzer dialysance for bicarbonate, ultrafiltration rate, blood flow rate and a targeted mid-dialysis plasma bicarbonate concentration of 25 mEq/L. Nine patients were studied over a 35 week period to verify this method of determining each patient's dialysate bicarbonate concentration. Prescribed dialysate bicarbonate concentrations for the nine patients varied from 29 to 38 mEq/L with five patients having a prescribed value of 35 mEq/L. After a baseline period of five weeks, five patients switched from a 37 mEq/L acetate dialysate to their prescribed dialysate bicarbonate concentration. Four patients who had already been on bicarbonate dialysis at a concentration of 35 mEq/L were dialyzed with their prescribed dialysate bicarbonate concentrations. Patients were then followed for a study period of 30 weeks. The prescribed dialysate bicarbonate concentration resulted in more normal acid/base chemistries for both groups of patients. The results also demonstrate that chronic hemodialysis patients require individualization of dialysate bicarbonate concentrations.


2008 ◽  
Vol 3 (2) ◽  
pp. 387-391 ◽  
Author(s):  
Mohammed Al-Ghonaim ◽  
Braden J. Manns ◽  
David J. Hirsch ◽  
Zhiwei Gao ◽  
Marcello Tonelli

2016 ◽  
Vol 63 (1) ◽  
Author(s):  
Ewa Weber ◽  
Tomasz Liberek ◽  
Wojciech Wołyniec ◽  
Marcin Gruszecki ◽  
Bolesław Rutkowski

Tunneled catheters are becoming increasingly used as a permanent dialysis access. Easy way of insertion and good long-term patency make them competitive to fistulas in some groups of patients. Late complications and survival of 180 tunneled catheters inserted from June 2010 to December 2013 in 171 unselected hemodialysis patients were analyzed. The cumulative time of observation was 2103.5 patient-months and median observation was 9 months (range of 0.5-45 months). Only 19 out of 180 catheters were removed due to complications (12 for infections, 4 due to malfunction and 3 because of mechanical damage). Majority of catheters were removed electively: 27 after maturation of arterio-venous fistula (AVF), 4 after kidney transplant, 5 after transfer to peritoneal dialysis and 3 due to the recovery of renal function. At the end of the observation, 58 catheters were still in use and 64 patients had died with functioning catheter. When censored for elective catheter removal and patient death, 88.2% of catheters survived for 1 year. Catheter survival was significantly better in older patients (over 65 years, in comparison to patients < 65 years, p = 0.046). Nearly 90% of all inserted catheters gave reliable dialysis access as long as it was needed. Among them, over 30% of the inserted catheters were in use at the end of the observation period, and over 30% of patients had died with a functioning catheter. The results of tunneled catheters survival are encouraging and they should be taken into consideration during decision-making on vascular access, especially in the older patients.


2001 ◽  
Vol 24 (7) ◽  
pp. 443-446 ◽  
Author(s):  
K.M. Chow ◽  
C.C. Szeto ◽  
C.B. Leung ◽  
T. Y.H. Wong ◽  
P.K.T. Li

Background Hemodialysis access is a challenging problem in patients with exhausted dialysis access sites of their upper extremities. Femoral arterio-venous polytetrafluoroethylene (PTFE) graft is often necessary. The safety and efficacy of cuffed tunneled catheters at the femoral site for long-term hemodialysis has not been extensively studied. Methods We inserted 14 cuffed-tunneled femoral catheters in 11 hemodialysis patients with exhausted dialysis access sites of their upper extremities. Access survival and risk of infection were compared with the 11 femoral PTFE grafts in 10 patients of our center during the same period. The choice of dialysis access was determined by the individual nephrologist. Access survival was defined as the achievement of a blood flow rate of at least 180 ml/min. Results The median survival of tunneled femoral catheter and PTFE graft were 166 days and 560 days respectively (log-rank test, p = 0.33). Seven of the 14 tunneled femoral catheter remained in use 3 months after insertion. The incidence of catheter- or graft-related infection was 0.38 and 0.23 episodes per 100 catheter / graft days for tunneled femoral catheters and PTFE graft respectively (p = 0.6). Five tunneled catheters and one PTFE graft had to be removed because of infection. Blood flow rates achieved were comparable between tunneled femoral catheter and PTFE graft. Conclusions Our preliminary data suggest that the cuffed tunneled femoral catheter has reasonable access survival and an acceptable risk of infection. It may provide a safe and effective access for long-term hemodialysis patients with exhausted access in their upper extremities, especially high risk patients who are not suitable for femoral PTFE graft creation.


2020 ◽  
Author(s):  
FAYE Moustapha ◽  
Niakhaleen KEITA ◽  
Maria Faye ◽  
Yousseph BERDAI ◽  
Ahmed Tall LEMRABOTT ◽  
...  

Abstract Background: The objective of this work was to assess the impact of the decrease in dialysate flow rate on the dialysis dose delivered (spKt /V) to chronic hemodialysis patients and to estimate the resulting water saving. Methods: It was a prospective 4-week-period study that included chronic hemodialysis patients with clinical and hemodynamic stability. The patients successively underwent hemodialysis with a dialysate flow rate of 500 ml / min, at 1, 1.2 and 1.5 times the blood flow rate. Each dialysate flow rate was applied for one week. During these 4 weeks, the following parameters were kept constant: duration of dialysis, blood flow rate, anticoagulation, membrane nature and surface. Results: Forty-five chronic hemodialysis patients were included with a mean age of 48.4 ± 12.07 years. The weekly average spKt/V was statistically higher with a dialysate flow rate at 1.5 times the blood flow rate compared to the dialysate flow at 500 mL / min (p = 0.001). The proportion of patients achieving a standardized dialysis dose ≥ 1.4 was statistically higher with dialysate flow at 500 mL / min (64.4%) compared to dialysate flow at 1 or 1.2 times the blood flow rate which were 57.8% and 55.6%, respectively. It was statistically higher with a dialysate flow at 1.5 times the blood flow (93.3%) compared to the dialysate flow at 500 mL / min (p = 0.036). The dialysate volume used with a dialysate flow rate of 500 mL / min was higher compared to the other dialysate flow rates (p = 0.0001). Conclusions: An adequate dialysis dose could be achieved with a dialysate flow rate of 1.5 times the blood flow rate, thereby saving significant amount of water.


2020 ◽  
Author(s):  
Romain Vial ◽  
Marion Gully ◽  
Mickael Bobot ◽  
Violaine Scarfoglière ◽  
Philippe Brunet ◽  
...  

Abstract Background: Daily management to shield chronic dialysis patients from SARS-CoV-2 contamination makes patient care cumbersome. There are no screening methods to date and a molecular biology platform is essential to perform RT-PCR for SARS-CoV-2; however, accessibility remains poor. Our goal was to assess whether the tools routinely used to monitor our hemodialysis patients could represent reliable and quickly accessible diagnostic indicators to improve the management of our hemodialysis patients in this pandemic environment.Methods: In this prospective observational diagnostic study, we recruited patients from La Conception hospital. Patients were eligible for inclusion if suspected of SARS-CoV-2 infection when arriving at our center for a dialysis session between March 12th and April 24th 2020. They were included if both RT-PCR result for SARS-CoV-2 and cell blood count on the day that infection was suspected were available. We calculated the area under the curve (AUC) of the receiver operating characteristic curve.Results: 37 patients were included in the final analysis, of which 16 (43.2%) were COVID-19 positive. For the day of suspected COVID-19, total leukocytes were significantly lower in the COVID-19 positive group (4.1 vs 7.4 G/L, p=0.0072) and were characterized by lower neutrophils (2.7 vs 5.1 G/L, p=0.021) and eosinophils (0.01 vs 0.15 G/L, p=0.0003). Eosinophil count below 0.045 G/L identified SARS-CoV-2 infection with AUC of 0.9 [95% CI 0.81-1] (p<0.0001), sensitivity of 82%, specificity of 86%, a positive predictive value of 82%, a negative predictive value of 86% and a likelihood ratio of 6.04.Conclusions :Eosinophil count enables rapid routine screening of chronic hemodialysis patients suspected of being COVID-19 within a range of low or high probability.


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