# N4 — UF Rate and Treatment Time

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.  **Review flag: 13 mL/kg/h.** Higher rates are associated with harm, but 13 is not a universally safe ceiling. Follow the patient’s authorized limit and reassess tolerance and volume status \[[1](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-1)\].
4.  **Heart failure:** risk may increase even at 10–13 mL/kg/h; ask the prescriber whether a lower limit or longer treatment is needed \[[2](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-2)\].
5.  **Patients over 80 kg:** also review the absolute rate; observational risk above about 1,000 mL/h supports an individualized limit rather than a size-based guarantee \[[3](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-3)\].
6.  If the goal will not fit within the patient’s authorized rate limit, request longer treatment or another session; use the unit’s standing order only when applicable.

*Arithmetic examples at 13 mL/kg/h, capped at 1,000 mL/h; these are not patient-specific safe removal goals. A lower ordered rate requires recalculation \[[1](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-1),[3](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-3)\]:*

| 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 \[[1](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-1),[3](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-3)\].
- 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 \[[5](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-5)\].

Interpretation: [KDIGO blood pressure and volume conference report (2020)](https://pubmed.ncbi.nlm.nih.gov/32278617/) emphasizes individualized UF decisions; one threshold does not suit every patient or treatment.

### 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 \[[6](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-6)\].

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 \[[1](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-1)\]. Above 13 versus 10 or less: HR 1.59 in the HEMO cohort \[[2](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-2)\].
2.  Heart failure patients showed excess risk even at 10–13 mL/kg/h \[[2](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-2)\].
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 \[[3](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-3)\].
4.  Each extra 30 minutes of treatment time was associated with about 6% lower mortality \[[4](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-4)\]; the long weekend gap carries the most heart failure and arrhythmia admissions \[[5](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-5)\].
5.  Routine sodium profiling was associated with higher mortality (HR 1.36) \[[6](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html#n4-ref-6)\].

### Go deeper

- Mastery page: [Ultrafiltration rate and treatment time](https://urinenephrology.org/mastery/maintenance-hd/ultrafiltration-rate-treatment-time.html)
- [All dialysis nursing reference cards](https://urinenephrology.org/mastery/maintenance-hd/nursing/index.html)

### References

1.  Assimon MM, et al. Ultrafiltration rate and mortality in maintenance hemodialysis patients. *Am J Kidney Dis.* 2016;68:911-922. [PubMed 27575009](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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.


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[Website version](https://urinenephrology.org/mastery/maintenance-hd/nursing/N4-UF-Rate-and-Treatment-Time.html) · Markdown synchronized October 3, 2026.