SIGNIFICANT BLOOD LOSS DURING THE FIRST 24HR AFTER HIP FRACTURE

Abstract

While hidden blood loss has been shown to occur in hip fractures the timing and cause have not yet been demonstrated. This study investigated the degree of pre-operative blood loss within the first 24hrs after intertrochanteric hip fracture.

188 patients with extracapsular hip fractures had their full blood count taken on admission and after 24 hours. The haemoglobin (Hb) and haematocrit (Hct) were noted at each time. Fractures were grouped as undisplaced or displaced. Those who were operated on prior to the 24hr blood sample were excluded. All patients with intracapsular or sub-trochanteric fractures were excluded, as were any who received a blood transfusion prior to their 24hr blood sample being taken. The tests for differences between blood samples and the existence of displacement were performed using paired and independent Student’s t-test. The level of significance was set at P< 0.05. All data was analysed using SPSS statistical software version 11.

The overall fall in the Hb within 24hr was significant (1.6 g/dl, P< 0.001), as was the fall in the haematocrit (0.05, P< 0.05). Displaced fractures had a significantly lower Hb at 24hrs than undisplaced (10.6g/dl vs 11.8 g/dl, P=0.001). The fall in Hb was significantly greater in displaced fractures compared to undisplaced (1.7g/dl vs 1.2g/dl, P< 0.05). Changes in the Hct mirrored those of the Hb.

This study identified a significant blood loss that occurs within the first 24hrs after an intertrochanteric hip fracture, prior to theatre. The cause is unlikely to be secondary to dehydration as the Hct fell with the Hb. Thus the most likely cause is the trauma itself. The admission Hb is possibly an inaccurate measure of the true value and patients may be more shocked than first thought. A more liberal resuscitation policy may be warranted.