CKD anemia content reviewed November 6, 2026 against KDIGO 2026. See the population-specific KDIGO 2026 rules.
- Choose a mode: "Predict ΔHgb from volume" (you have an order in mL and want the expected rise) or "Compute volume to reach target Hgb" (you want to back-calculate the mL needed).
- Enter weight (kg or lb), pick the age category (sets blood volume per kg: neonate 90, infant 80, child 75, adolescent/adult 70 mL/kg), and the patient's current Hgb in g/dL.
- Select the blood product (PRBC Hct ≈ 60% / whole blood ≈ 38% / reconstituted ≈ 51%, or enter a custom donor Hct). Hgb of the unit is taken as Hct ÷ 3.
- Enter the volume to transfuse (Mode A) or the target Hgb (Mode B). Result updates as you type and is colour-coded by severity.
For chronic CKD anemia, use symptoms, signs, and the clinical setting to decide on transfusion. This volume predictor does not establish an indication. Acute coronary syndromes, active bleeding, and pediatric or disease-specific transfusion programs require their own protocols. All computation runs in your browser; no values are stored or transmitted.
When to use
For chronic anemia in CKD, base red-cell transfusion on symptoms and signs attributable to anemia and the individual balance of benefits and harms, rather than an arbitrary Hb threshold (practice point 4.4). Restrictive thresholds from other settings are context-specific and are not universal CKD orders.
Acute hemorrhage, unstable coronary disease, or urgent surgery may require rapid correction. Avoid transfusion when possible in transplant candidates to reduce allosensitization. Leukoreduction does not eliminate sensitization risk. When transfusion is appropriate, account for volume overload, potassium, iron burden, and reassess the response; stable patients are often managed one unit at a time under local protocols.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
CKD transfusion decisions
For chronic anemia in CKD, base red-cell transfusion on symptoms and signs attributable to anemia and the individual balance of benefits and harms, rather than an arbitrary Hb threshold (practice point 4.4). Restrictive thresholds from other settings are context-specific and are not universal CKD orders.
Acute hemorrhage, unstable coronary disease, or urgent surgery may require rapid correction. Avoid transfusion when possible in transplant candidates to reduce allosensitization. Leukoreduction does not eliminate sensitization risk. When transfusion is appropriate, account for volume overload, potassium, iron burden, and reassess the response; stable patients are often managed one unit at a time under local protocols.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
Why Use It
Restrictive transfusion thresholds — Hgb 7 g/dL for stable patients, 8 g/dL with cardiac disease or acute coronary syndrome — are now the standard of care for adult inpatients, supported by TRICC, FOCUS, TRISS, and the 2016/2023 AABB guidelines. Yet day-to-day RBC ordering still often defaults to "two units" without estimating what one unit will actually do, or sizing the order to the patient's weight and pre-transfusion Hgb. This tool replaces that default with a one-screen quantitative check: this much donor Hgb, diluted into this estimated blood volume, will move the patient's Hgb by approximately this much. For paediatric dosing it formalizes the 10–15 mL/kg habit; for CKD and HF it surfaces the volume-overload risk that drives the 4-hour infusion and inter-unit diuretic; and for chronic transfusion-dependent patients it makes the cumulative iron burden visible early.
Transfusion Hemoglobin Predictor
Choose a mode, enter the patient's weight and current Hgb, pick the donor product, then enter either the volume to transfuse (Mode A) or the target Hgb (Mode B). The result reports the predicted ΔHgb (Mode A) or required volume in mL, mL/kg, and adult-unit estimate (Mode B), with a colour-coded safety check against bedside transfusion rules.
⚕ Estimate only. Donor unit Hct (typically 55–70% for PRBC), plasma-volume shifts, ongoing blood loss, hemolysis, and splenic sequestration can move the actual post-transfusion Hgb away from the predicted value. Always check the actual ordered unit volume on the label, infuse over 2–4 hours per unit (4 h in CKD/HF/elderly with inter-unit IV furosemide 0.5–1 mg/kg if volume overload risk), and verify with a post-transfusion CBC drawn 15 min–1 h after the unit completes.
Next steps
For chronic anemia in CKD, base red-cell transfusion on symptoms and signs attributable to anemia and the individual balance of benefits and harms, rather than an arbitrary Hb threshold (practice point 4.4). Restrictive thresholds from other settings are context-specific and are not universal CKD orders.
Acute hemorrhage, unstable coronary disease, or urgent surgery may require rapid correction. Avoid transfusion when possible in transplant candidates to reduce allosensitization. Leukoreduction does not eliminate sensitization risk. When transfusion is appropriate, account for volume overload, potassium, iron burden, and reassess the response; stable patients are often managed one unit at a time under local protocols.
Source: KDIGO 2026 Anemia in CKD, recommendations 2.1–2.4 and 3.2.1–3.3.1; practice points 2.2–2.8 and 3.4.1.2–3.4.3.5. Reviewed November 6, 2026. Apply clinical judgment and the locally approved product label.
Evidence & References
Formulae
| Quantity | Formula |
|---|---|
| Total blood volume (mL) | Weight (kg) × BVper kg (90 neonate · 80 infant · 75 child · 70 adolescent/adult) |
| Donor Hgb in unit (g/dL) | Donor Hct (%) ÷ 3 (PRBC ≈ 22 · whole blood ≈ 14 · reconstituted ≈ 17) |
| Mode A — Predicted ΔHgb (g/dL) | Volume (mL) × Hgbproduct ÷ Total blood volume (mL) |
| Mode B — Required volume (mL) | (Target − Current Hgb) × Total blood volume ÷ Hgbproduct |
| Adult-unit estimate | ceil(Volume ÷ 300 mL per PRBC unit) — reported for adults only |
Bedside cross-checks
| Rule | Use |
|---|---|
| 10 mL/kg PRBC ≈ 2–3 g/dL rise | Sanity-check Mode A in paediatric dosing. |
| 1 adult unit PRBC ≈ 1 g/dL rise in a 70-kg adult | Sanity-check Mode A in adults; expect lower rise in larger patients, higher in smaller. |
| 1 unit PRBC ≈ 200 mg elemental iron | Track cumulative iron in chronic-transfusion patients (chelation referral once ferritin trends > 1000 ng/mL or after ~20 lifetime units). |
| Post-transfusion CBC timing | 15 min – 1 h after the unit completes (steady-state). |
The conservation equation (donor red-cell mass distributes into the recipient's circulating blood volume) underlies both modes; bedside rules-of-thumb are empirical simplifications of this equation in typical patient sizes and donor-unit Hcts. Modern transfusion practice frames the indication against TRICC/FOCUS/TRISS-era restrictive thresholds rather than a fixed two-unit habit.
References
- Carson JL, Stanworth SJ, Dennis JA, et al. Transfusion thresholds for guiding red blood cell transfusion. Cochrane Database Syst Rev. 2021;12(12):CD002042. doi:10.1002/14651858.CD002042.pub5.
- Carson JL, Guyatt G, Heddle NM, et al. Clinical Practice Guidelines From the AABB: Red Blood Cell Transfusion Thresholds and Storage. JAMA. 2016;316(19):2025–2035. doi:10.1001/jama.2016.9185.
- Davenport RD. Pediatric transfusion. In: Simon TL, McCullough J, et al, eds. Rossi's Principles of Transfusion Medicine. 5th ed. Wiley; 2016.
- Kidney Disease: Improving Global Outcomes (KDIGO). Clinical Practice Guideline for Anemia in CKD. Kidney Int Suppl. 2012;2(4):279–335.
