Table I.
Demographic and clinical data of two series of patients undergoing surgery for total knee arthroplasty, managed with (reinfusion group) or without (control group) post-operative reinfusion of unwashed shed blood.
| Control group | Reinfusion group | p | Effect size Cohen's d | |
|---|---|---|---|---|
| Patients (n.) | 330 | 763 | ---- | ---- |
| Gender (male/female) | 82/248 | 145/618 | 0.035 | ---- |
| Age (years) | 71±5 | 70±7 | 0.074 | 0.16 |
| Weight (kg) | 74±19 | 76±17 | 0.036 | 0.11 |
| EBV (mL) | 4,895±1,289 | 5,058±1,126 | 0.084 | 0.13 |
| Pre-operative Hb (g/dL) | 13.6±1.2 | 13.5±1.2 | 0.233 | 0.08 |
| RBC mass (mL) | 2,284±640 | 2,294±566 | 0.331 | 0.02 |
| 48 h post-operative Hb (g/dL) | 9.9±2.1 | 10.1±1.6 | 0.128 | 0.11 |
| ARCT units, n (%) | ||||
| 0 | 249 (75.5) | 698 (91.5) | ||
| 1 | 8 (2.4) | 4 (0.5) | 0.001 | ---- |
| 2 | 56 (17.0) | 54 (7.1) | ||
| 3 | 11 (3.3) | 4 (0.5) | ||
| 4 | 6 (1.8) | 3 (0.4) | ||
| Pre-ARCT Hb (g/dL) | 7.6±1.4 | 7.7±1.1 | 0.905 | 0.08 |
| Post-operative infection, n. (%) | 13 (3.9) | 16 (2.1) | ||
| Surgical wound | 5 | 5 | ||
| Pneumonia | 1 | 2 | 0.148 | ---- |
| Urinary tract | 5 | 9 | ||
| Sepsis | 1 | 0 | ||
| Cellulitis | 1 | 0 | ||
| Length of hospital stay (days) | 12.1±4.4 | 9.5±3.6 | 0.001 | 0.65 |
Legend ARCT: allogeneic red cell transfusion; EBV: estimated blood volume; Hb: haemoglobin; Pre-ARCT Hb: haemoglobin level prior to ARCT; RBC mass: circulating red cell mass.
Data are expressed as mean ± SD, or incidence and %.