Retrograde Autologous Priming · Pre-Bypass Hematocrit Prediction
Shackelford · AGS Perfusion LLC · Version 2.0
Core Formulas (Shackelford, 2005)
• Anticipated On-Bypass Hct = (PBV × Preop Hct) ÷ (PBV + Total Prime)
• RAP Volume = Total Prime − [PBV × (Starting Hct − Target Hct) ÷ Target Hct]
• pRBC Volume = [(Target Hct − Anticipated Hct) × TCV] ÷ pRBC Hct
PBV = Weight × 70 ml/kg (male) / 60 ml/kg (female) | Total Dilution = Circuit Prime + CP Crystalloid + Pre-CPB Anesthesia Volume
→ Dilution contribution: 800 ml of 1000 ml total
IV fluids, flush volumes given pre-bypass
Required RAP Volume (ml) to achieve on-bypass Hct of 24%
Prime: 1800 ml + CP crystalloid: 800 ml (1000 ml × 80%) + Pre-CPB Anesthesia: 300 ml = Total dilution: 2900 ml · PBV = 70 ml/kg
| Wt (kg) | Hct 40% | Hct 38% | Hct 36% | Hct 34% | Hct 32% | Hct 30% |
|---|---|---|---|---|---|---|
| 70 | N/A | 42 | 450 | 858 | 1267 | 1675 |
| 75 | N/A | N/A | 275 | 712 | 1150 | 1588 |
| 80 | N/A | N/A | 100 | 567 | 1033 | 1500 |
| 85 | N/A | N/A | N/A | 421 | 917 | 1413 |
| 90 | N/A | N/A | N/A | 275 | 800 | 1325 |
| 95 | N/A | N/A | N/A | 129 | 683 | 1238 |
| 100 | N/A | N/A | N/A | N/A | 567 | 1150 |
| 105 | N/A | N/A | N/A | N/A | 450 | 1063 |
| 110 | N/A | N/A | N/A | N/A | 333 | 975 |
N/A = No RAP needed (baseline Hct ≥ target) · >Max = Blood prime required · Red = large RAP volume (>1400 ml)
GDP-CS Version 2.0 · RAP & Dilutional Hematocrit Module
Shackelford AG · AGS Perfusion LLC · For Clinical Decision Support Use