Clinical analysis of peri-operative hidden blood loss of elderly patients with intertrochanteric fractures treated by unreamed proximal femoral nail anti-rotation

The purpose of this study was to quantify the peri-operative blood loss of elderly patients with intertrochanteric fractures treated by unreamed proximal femoral nail anti-rotation (PFNA) and analyze whether the substantial hidden blood loss was induced by initial trauma or the operation. The clinical data of 123 patients with intertrochanteric fracture treated with unreamed PFNA from Jan 2013 to Apr 2017 were analyzed retrospectively. Blood routine on admission day (ADM), pre-operative day one (PRE), post-operative days one and three (POD1 and POD3) and the visible blood loss (VBL) were obtained. The total blood loss (TBL) from ADM to POD1 and POD3 were 693.5 ± 359.6 ml and 863.8 ± 429.9 ml, of which the corresponding hidden blood loss (HBL) was 86.8% and 89.4% respectively. The mean TBL and HBL from ADM to PRE (375.5 ± 242.0 ml, 375.5 ± 242.0 ml) were higher than that from PRE to POD1 (318.0 ± 183.4 ml, 226.5 ± 163.2 ml), p < 0.001 respectively. There was no significant difference between HBL from ADM to PRE and HBL from PRE to POD3 (375.5 ± 242.0 ml, 396.7 ± 254.0 ml, p = 0.361). The majority of peri-operative HBL occurred before surgery, it was mainly associated with the initial trauma rather than the operation.