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For educational use only — The physician’s written order and the unit protocol always govern
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Dialysis Nursing Reference Card  ·  Maintenance Hemodialysis

N4 — UF Rate and Treatment Time

Remove the fluid without exceeding a safe ultrafiltration (UF) rate. When it won't fit, add time — not rate.
Andrew Bland, MD, FACP, FAAP Reviewed September 2026 · v1.0 draft Prints on one sheet, front and back
N4 — UF Rate and Treatment Time FRONT
Front · at the chair

When: setting the UF goal at the start of every treatment.

Do this

  1. UF goal = weight above target + rinse-back and saline + intake during treatment (per unit practice).
  2. UF rate (mL/kg/h) = UF goal (mL) ÷ hours ÷ target weight (kg).
  3. Ceiling: 13 mL/kg/h. It is a ceiling, not a goal — lower is better; below 10 when possible [1].
  4. Heart failure: aim for 10 mL/kg/h or less [2].
  5. Patients over 80 kg: also keep the absolute rate at or below about 1,000 mL/h [3].
  6. If the goal won’t fit under the ceiling, extend time per your unit protocol’s standing order, using the table.

Most fluid that fits at 13 mL/kg/h, capped at 1,000 mL/h [1,3]:

Target weight 4 h 4.5 h 5 h
50 kg 2.6 L 2.9 L 3.2 L
60 kg 3.1 L 3.5 L 3.9 L
70 kg 3.6 L 4.1 L 4.5 L
80 kg or more 4.0 L (cap) 4.5 L (cap) 5.0 L (cap)

Call the nephrologist when

  • The fluid won’t fit even with the extension your protocol allows — an extra session may be needed.
  • The UF rate exceeded 13 mL/kg/h, or about 1,000 mL/h in a patient over 80 kg, in any session where time could not be extended [1,3].
  • The patient refuses extra time.
  • High potassium or a missed treatment accompanies the fluid gain — this needs full dialysis, not UF alone.
  • The gain after the long weekend is repeatedly the problem [5].

Don’t

  • Don’t raise the UF rate to “catch up” on the target in the same time.
  • Don’t treat 13 mL/kg/h as a goal to reach.
  • Don’t use isolated UF when potassium or clearance is the issue.
  • Don’t use sodium profiling to push more fluid off [6].
N4 — UF Rate and Treatment Time BACK
Back · why, and the evidence

Why

  1. Mortality rose about 3% for each 1 mL/kg/h of UF rate, starting below 10 [1]. Above 13 versus 10 or less: HR 1.59 in the HEMO cohort [2].
  2. Heart failure patients showed excess risk even at 10–13 mL/kg/h [2].
  3. At 13 mL/kg/h, risk was much higher for a 100-kg patient than a 60-kg patient; above 1,000 mL/h, risk was high regardless of size [3].
  4. Each extra 30 minutes of treatment time was associated with about 6% lower mortality [4]; the long weekend gap carries the most heart failure and arrhythmia admissions [5].
  5. Routine sodium profiling was associated with higher mortality (HR 1.36) [6].

Go deeper

References

  1. Assimon MM, et al. Ultrafiltration rate and mortality in maintenance hemodialysis patients. Am J Kidney Dis. 2016;68:911-922. PubMed 27575009
  2. Flythe JE, et al. Rapid fluid removal during dialysis is associated with cardiovascular morbidity and mortality. Kidney Int. 2011;79:250-257. PubMed 20927040
  3. Raimann JG, et al. Ultrafiltration rate thresholds associated with increased mortality risk in hemodialysis, unscaled or scaled to body size. Kidney Int Rep. 2022;7:1585-1593. PubMed 35812299
  4. Tentori F, et al. Longer dialysis session length is associated with better intermediate outcomes and survival (DOPPS). Nephrol Dial Transplant. 2012;27:4180-4188. PubMed 22431708
  5. Foley RN, et al. Long interdialytic interval and mortality among patients receiving hemodialysis. N Engl J Med. 2011;365:1099-1107. PubMed 21992122
  6. Dasgupta I, et al. Associations between hemodialysis facility practices to manage fluid volume and intradialytic hypotension and patient outcomes. Clin J Am Soc Nephrol. 2019;14:385-393. PubMed 30723164

Reviewed by Andrew Bland, MD, FACP, FAAP · v1.0 draft 2026-09-26. For education; the physician’s written order and the unit protocol always govern.