Measure of adequacy of dialysis:
Relationship between URR and spKt/V ( single pool Kt/V):
URR (Urea Reduction ratio)= predialysis BUN-postdialysis BUN/ predialysis BUN X 100
spKt/V dimensionless unit- refers to amount of plasma cleared of urea corrected for volume of distribution of urea. K (dialyzer clearence L/hr) X t (duration of dialysis hr)/V (Volume of distribution of urea L).
Relationship between URR and spKt/V:
so based on above equation, for Kt/V of 1.0 URR should be 0.63 ( i.e. 63% urea extraction) however this equation does not account for urea generation during dialysis ( will increase postdialysis BUN) and ultrafiltration( which will remove urea by convection) so corrected equation is:
spKt/V = -ln(R – 0.008 x t) + (4 - 3.5 x R) x 0.55 UF/V
(where R = 1 – URR, V = postdialysis volume distribution, UF=volume of fluid removed)
0.008 x t is correction for urea generation which is dependent on time and 0.55UF/V is correction for ultrafiltration. Therefore, for Kt/V of 1.0, URR actually is 60% (if there is no ultrafiltration) instead of 63%.
Remember that URR we see, does not account for urea generation and ultrafiltration which can change the amount of dialysis a patient is actually getting.
eKT/V which is equillibrated Kt/V takes into account for rebound. Rebound is seen because of sequestration of urea in muscle which is rich in water and hence urea but has poor blood flow, thereby limiting the extration of urea into blood. At the end of dialysis, this urea is released from the tissues because of concentration gradient causing rebound. Hence eKt/V is lower than spKt/V by 0.21 for each dialysis.
- ► 2023 (17)
- ► 2022 (18)
- ► 2021 (36)
- ► 2020 (32)
- ► 2019 (42)
- ► 2018 (57)
- ► 2017 (52)
- ► 2016 (45)
- ► 2015 (63)
- ► 2014 (95)
- ► 2013 (133)
- ► 2012 (201)
- ► 2011 (370)
- Virtual Grand Rounds in Nephrology- E nephrology
- ASN's review on the ESRD bundling
- TOPIC DISCUSSION: EFFECT OF PROTEINURIA on combina...
- Poem from Pediatric Nephrologist
- TOPIC DISCUSSION: ACE induce angioedema replaced b...
- Nephsap review: Chronic Kidney Disease : CKD patie...
- Nephsap review: Chronic Kidney Disease: Troponin T...
- Bundled Payment for ESRD
- 2010 North American Dialysis and Transplantation (...
- Hematuria and Donation?
- TOPIC DISCUSSION: Do Peritoneal Dialysis patients ...
- Renal Fellow Network: Deciphering the pathologists...
- TOPIC DISCUSSION: TIDAL PD
- TOPIC DISCUSSION: DEXA SCAN in TRANSPLANT PATIENTS?
- CLINICAL CASE 21, ANSWERS AND SUMMARY
- Plagiarism In Application Essays????
- Micro RNAs and Transplantation
- IN THE NEWS: Anabolic Steroids and FSGS
- CLINICAL CASE 20, ANSWERS AND SUMMARY
- Pediatrics Grand rounds continue
- CONSULT ROUNDS: Severe Pre eclampsia
- Milk and CKD
- Transplant/Immunology Quiz 3 answers
- Rituximab and Cyclophosphamide: A Tale of Two Trea...
- CONSULT ROUNDS: HUS/TTP During Pregnancy
- IN THE NEWS: FACTOR H REPLETION in Atypical HUS
- Leflunomide and liver failure
- TOPIC DISCUSSION: Gadolinium and NSF- How to image...
- Lupus Nephritis Post Transplant
- Why do Internal Medicine Residents Choose Nephrolo...
- TOPIC DISCUSSION: TTP/HUS
- CONSULT ROUND: Hypercalcemia and Lithium
- CONSULT ROUND: ATHEROEMBOLIC DISEASE
- CONSULT ROUNDS:Rare and Interesting Cause of Hyper...
- TOPIC DISCUSSION: URR and Kt/V
- Organ Trading Discussion
- Dietary Management of Hypertension
- Chronic Dialysis: Now or Later?
- Photopheresis therapy for renal allograft rejection?
- IN THE NEWS --->google as a diagnostician
- Live Donor Nephrectomy with vaginal extraction
- CLINICAL CASE 19, ANSWER AND SUMMARY
- IN THE NEWS- HYPOMAGNESEMIA AND PPI?
- JOB MARKET for RENAL FELLOWS
- Nephron Power: NYSN Fellows Boot camp
- NYSN Fellows Boot camp
- TOPIC DISCUSSION: captopril and stones?
- Topic Discussion: D-Lactate vs D-lactic acid
- ▼ July (48)