Dialysis Pro · When a KPI is off-target
Dose Adjustment & Targets
Structured response to the common off-target results in maintenance HD: low Kt/V, high phosphate, abnormal PTH/calcium, fluid overload, hyperkalemia, and anaemia. Pairs with the KPI / Adequacy tile.
⚠️ Clinical reference only. Adult doses must be confirmed against local pharmacy protocol; targets individualised on serial trends, not single values. Developed by Dr. Abbas Deeb. Not affiliated with KDOQI, KDIGO, UpToDate, or any guideline body.
Low Kt/V — Workup
Delivered dose below target (see KPI tile for targets)
Delivered dose is below target (see KPI tile). In stable HD patients, ~40% of low Kt/V values are due to lower-than-prescribed blood flow or treatment time — often poor needle placement or patient-driven time constraints — and ~25% to access recirculation. A central venous catheter independently reduces delivered dose.
1
Initial assessment — four checks
| Check | What to look for |
|---|---|
| Vascular access integrity | Access recirculation (common cause); stenosis; CVC use reduces delivery |
| Treatment duration | Actual time < prescribed: late arrival, late start, early termination, intra-treatment interruptions (hypotension, alarms, needle issues) |
| BUN sampling method | Technical error → falsely low pre-BUN or high post-BUN lowers calculated Kt/V |
| Machine / patient variables | Calibration, low blood/dialysate flow rates, overestimated dialyzer clearance |
2
Secondary assessment / options to increase clearance
If the cause isn't quickly found or corrected, work to improve effective treatment time, correct sampling errors, and improve dialyzer clearance.
- ↑ Blood flow rate (BFR)
- ↑ Dialysate flow rate (DFR)
- ↑ Dialyzer surface area
- ↑ Time (length, frequency, or both)
- Reduce dialyzer clotting
- Correct fistula recirculation
- Two dialyzers in series/parallel (very large patients)
The exception that needs time, not flow: if the limit is significant cardiopulmonary recirculation or delayed intracellular urea transfer, blood/dialysate flow and dialyzer size are already near-maximal — the only way to compensate is to increase time on dialysis.
Preserve residual kidney function where possible — it independently contributes to toxin removal.
Source: UpToDate "Prescribing and assessing adequate hemodialysis" (Apr 2026).
High Phosphate
Stepwise & additive · Dialysis removes only ~900 mg/session
Treatment trigger
>5.5
mg/dL (dialysis)
KDOQI / UpToDate target
3.5–5.5
mg/dL inclusive
Concurrent diet + binder
>6.5
mg/dL — start both
Treat on trends, not a single value. KDOQI/UpToDate use a numeric 3.5–5.5 mg/dL range; KDIGO 2017 instead lowers phosphate toward the normal range without a fixed number, treating progressively or persistently elevated values. UpToDate considers the KDIGO non-numeric approach impractical; both agree treatment targets overt hyperphosphatemia, not prevention.
Stepwise approach
1
Dietary phosphate restriction — 800–1000 mg/day
Dietitian-supervised (many HD patients have borderline malnutrition). Target processed foods and colas (additives are almost fully absorbed), not high-biologic-value protein (meat, eggs). Plant/phytate phosphorus (beans, nuts, legumes) is poorly absorbed and often acceptable. Never compromise protein intake.
2
Optimise dialysis
Ensure Kt/V target is met so phosphate removal is optimised (~900 mg removed per conventional session). Don't increase conventional dose just for phosphate — but frequent or nocturnal HD substantially lowers phosphate and may eliminate binder need.
3
Add phosphate binder — non-calcium preferred
Sevelamer (carbonate preferred if acidosis)
800–2400 mg TID with meals
Lanthanum carbonate 500–1000 mg TID with meals · chewed · lower pill burden
Sucroferric oxyhydroxide 2.5 g (= 500 mg iron) TID with meals · low pill burden
Ferric citrate Useful if iron-deficient (raises Hb/ferritin — monitor for overload)
Calcium carbonate / acetate restrict dose Elemental Ca from binder ≤1500 mg/day · total elemental Ca ≤2000 mg/day
Avoid: aluminium hydroxide (long-term), calcium citrate (↑ aluminium absorption), magnesium binders, nicotinamide
Lanthanum carbonate 500–1000 mg TID with meals · chewed · lower pill burden
Sucroferric oxyhydroxide 2.5 g (= 500 mg iron) TID with meals · low pill burden
Ferric citrate Useful if iron-deficient (raises Hb/ferritin — monitor for overload)
Calcium carbonate / acetate restrict dose Elemental Ca from binder ≤1500 mg/day · total elemental Ca ≤2000 mg/day
Avoid: aluminium hydroxide (long-term), calcium citrate (↑ aluminium absorption), magnesium binders, nicotinamide
All binders are equally effective when titrated. Use the lowest effective dose; binders work only when taken with meals. KDIGO 2017 recommends restricting calcium-based binders across all severities (2B), not only with hypercalcemia.
4
Review hyperparathyroidism treatment
In dialysis patients with refractory phosphate, use calcimimetics to suppress PTH and minimise calcitriol / vitamin D analogs (active vitamin D increases GI phosphate absorption; high PTH releases phosphate from bone). See PTH & Calcium section.
5
Add tenapanor — refractory cases
Tenapanor
10–30 mg BID · for phosphate persistently >5.5 despite diet + optimal HPT treatment + appropriate binders
Diarrhoea in ~50% (drug discontinued for it in ~5%). Some experts use a higher threshold (>6.5) given no proven outcome benefit of lowering below 5.5.
Diarrhoea in ~50% (drug discontinued for it in ~5%). Some experts use a higher threshold (>6.5) given no proven outcome benefit of lowering below 5.5.
Source: UpToDate "Management of hyperphosphatemia in adults with CKD"; KDIGO 2017 CKD-MBD (rec 4.1.2, 4.1.6, 4.1.8).
PTH & Calcium (CKD-MBD)
Treat on trends · Phosphate, calcium & PTH considered together
iPTH target (G5D)
2–9×
upper normal limit
Dialysate calcium
1.25–1.50
mmol/L (2.5–3.0 mEq/L)
Serum calcium
avoid ↑
avoid hypercalcemia
Treat on trends, not isolated values (KDIGO 2017): base all CKD-MBD treatment on serial assessments of phosphate, calcium, and PTH considered together — never the Ca×P product. Marked movement of PTH in either direction within the 2–9× range should prompt initiating or changing therapy.
1
High PTH — PTH-lowering therapy (all first-line, alphabetical)
KDIGO does not prioritise one agent. Choice guided by concurrent calcium and phosphate levels and dialysate calcium.
- Calcimimetics (cinacalcet / etelcalcetide)
- Calcitriol
- Vitamin D analogs
- or a combination
Reduce/stop calcitriol or vitamin D sterol if hypercalcemia. Reduce/stop vitamin D sterol if hyperphosphatemia. Reduce/stop calcimimetic if hypocalcemia (though mild asymptomatic hypocalcemia on a calcimimetic can be tolerated to avoid calcium loading). If iPTH falls below ~2× upper normal → reduce/stop therapy.
2
Calcium management
Avoid hypercalcemia in adults. Restrict calcium-based phosphate binders (elemental Ca ≤1500 mg/day from binder, ≤2000 mg/day total). Adjust dialysate calcium within 1.25–1.50 mmol/L. Treat significant or symptomatic hypocalcemia (risk of bone disease, worsening HPT, QTc prolongation).
3
Refractory severe hyperparathyroidism
Parathyroidectomy if severe HPT fails medical/pharmacological therapy (KDIGO rec 4.2.5).
Source: KDIGO 2017 CKD-MBD (rec 4.1.1, 4.1.3, 4.1.4, 4.2.3, 4.2.4, 4.2.5).
Fluid Overload / Target Weight Not Achieved
Lower the UFR by adding time — not by removing faster
If target weight can't be reached — or only with rapid ultrafiltration — fluid removal is inadequate. Persistent hyponatremia often signals volume overload; address it with ultrafiltration, not free-water restriction alone.
1
Reduce interdialytic gain
Sodium restriction <2000 mg/day to reduce thirst; continue diuretics if residual urine output; target interdialytic weight gain 1–1.5 kg.
2
For persistent large gains → add time, lower UFR
Increase session length or frequency to allow a lower ultrafiltration rate. Recall the harm thresholds: UFR >10 mL/h/kg → +22% mortality; >13 → +31% (see KPI tile). The goal is a gentler UFR, not faster fluid removal.
3
Address barriers
Common barriers: need for longer treatment times, IDH/cramping with aggressive UF, reimbursement limits on extra sessions, patient reluctance to extend time or restrict sodium, and clinician-side delays in adjusting the prescription or providing dietary counselling.
Source: UpToDate "Prescribing and assessing adequate hemodialysis" (Apr 2026); KDOQI 2015.
Persistent Hyperkalemia
Usually dietary — but exclude inadequate dialysis
Exclude inadequate dialysis before blaming diet. Persistent hyperkalemia usually reflects dietary nonadherence — but access recirculation can also contribute and will show up as a low Kt/V. Always cross-check the delivered dose first.
1
Confirm adequate clearance
Review Kt/V and assess for access recirculation before attributing to diet (see Low Kt/V workup).
2
Management options
- Dietary potassium counselling
- Optimise / review dialysate K⁺
- Add an extra dialysis session per week
- Potassium binders on non-dialysis days
Dialysate K⁺ optimisation is the primary lever for dialysis-related potassium control. Avoid very low dialysate K⁺ (<2 mEq/L) in patients at arrhythmia risk — see the Arrhythmia protocol in the Complications module. For acute intradialytic hyperkalemia management, see Complications → Hemolysis/arrhythmia.
Source: UpToDate "Prescribing and assessing adequate hemodialysis" (Apr 2026).
Anaemia / Iron / ESA
Iron first → ESA/HIF-PHI if Hb <10 → investigate non-response
Hb target range
10–11.5
g/dL
Never target
≥13
g/dL (NHT harm)
ESA/HIF start
Hb <10
after iron optimised
Optimise iron first, then add ESA/HIF-PHI if Hb stays <10 g/dL, then investigate non-response. The goal is symptom relief and transfusion avoidance — not normalising Hb. Monitor Hb monthly; TSAT and ferritin at least every 3 months.
1
Optimise iron FIRST (may avoid ESA entirely)
| Action | Threshold (CKD G5HD) |
|---|---|
| Initiate IV iron | Ferritin ≤500 ng/mL AND TSAT ≤30% |
| Withhold iron | Ferritin >700 ng/mL OR TSAT ≥40% |
| Suspend iron | During active bacterial/fungal infection |
IV iron preferred over oral in HD (PIVOTAL: proactive iron sucrose 400 mg/month unless ferritin >700 or TSAT ≥40% → lower ESA doses, fewer transfusions). Yearly HD iron loss ~1–2 g (≈100–200 mg/month). Maintenance IV iron for most patients unless ferritin >700 / TSAT ≥40% / active infection.
2
Add ESA if Hb <10 and iron-replete — ESA preferred over HIF-PHI
Epoetin alfa
50–100 units/kg 3×/week (higher end if Hb <8)
Darbepoetin alfa 0.45 mcg/kg weekly OR 0.75 mcg/kg every 2 weeks
Methoxy PEG-epoetin beta 0.6 mcg/kg every 2 weeks
Route: IV or SC in HD (SC needs ~25–30% less, lower CV risk; IV usually preferred for comfort/access). Adjust monthly.
Darbepoetin alfa 0.45 mcg/kg weekly OR 0.75 mcg/kg every 2 weeks
Methoxy PEG-epoetin beta 0.6 mcg/kg every 2 weeks
Route: IV or SC in HD (SC needs ~25–30% less, lower CV risk; IV usually preferred for comfort/access). Adjust monthly.
Titration safety: hold or reduce 25–50% if Hb rises >1 g/dL per 2 weeks (KDIGO) / >2 g/dL per month (UpToDate). Hold (not just reduce) if Hb >12 on two measurements a week apart. If Hb >11.5, reduce dose rather than discontinue. Suspend ESA during acute stroke or thrombosis. Don't repeatedly dose-escalate a non-responder — investigate hyporesponsiveness instead.
3
HIF-PHI — selected alternative (oral)
Consider for: ESA hyporesponsiveness/intolerance, ESA allergy / ESA-associated pure red cell aplasia, or preference for an oral agent (mainly PD / home HD). Discontinue after 3–4 months if no adequate response. Do not combine with an ESA.
Avoid HIF-PHI with: active cancer (or cancer not in remission ≥2–5 yr), history of stroke/MI, thromboembolism, vascular access thrombosis, significant hepatic impairment, PKD, proliferative retinal disease, pulmonary arterial hypertension, pregnancy. Drug-specific monitoring: vadadustat → LFTs (baseline, monthly ×6); roxadustat → TSH (baseline, monthly ×3; central hypothyroidism risk).
4
ESA hyporesponsiveness — investigate, don't escalate
Defined as failure to reach target despite significant dose increases, or needing persistently high doses. Identify and treat causes:
- Iron deficiency
- Iron sequestration from inflammation
- Suboptimal dialysis adequacy (check Kt/V)
- Occult blood loss
Note the loop back to adequacy: inadequate dialysis is a named cause of ESA resistance. A low Kt/V can present as a failing anaemia regimen. Transfusion is reserved for refractory/symptomatic cases — beware alloimmunisation reducing transplant suitability.
Source: KDIGO 2026 Anemia in CKD; UpToDate "Treatment of anemia in patients on dialysis"; PIVOTAL NEJM 2019; Normal Hematocrit Trial.
Dialysis Pro — Dose Adjustment & Targets · Sourced from UpToDate (adequacy, hyperphosphatemia, anemia topics), KDIGO 2017 CKD-MBD, and KDIGO 2026 Anemia. Literature current through 2026.
Developed by Dr. Abbas Deeb. For clinical reference only. All drug doses are for adults and must be confirmed against local pharmacy protocol; targets must be individualised on serial trends. Not affiliated with KDOQI, KDIGO, UpToDate, or any guideline body.
Developed by Dr. Abbas Deeb. For clinical reference only. All drug doses are for adults and must be confirmed against local pharmacy protocol; targets must be individualised on serial trends. Not affiliated with KDOQI, KDIGO, UpToDate, or any guideline body.