The hidden blood loss after hip fracture

Despite advances in surgical and anaesthetic techniques the mortality after hip fracture has not significantly changed in the last 40 years. Pre-operative anaemia is a risk factor for peri-operative death. We speculate that a significant proportion of the blood loss related to hip fractures has occurred prior to surgery. Identifying patients at risk of pre-operative anaemia can facilitate appropriate medical optimisation. This study is unique in its attempt to quantify the blood loss associated with the initial hip injury.

In a retrospective study all patients with both a diagnosis of hip fracture and an operative delay of >48 h were assessed. The information collected included: fracture classification, serial haemoglobins and patient co-morbidities. The exclusion criteria included a pre-injury diagnosis of anaemia, anti-coagulation and gastrointestinal bleeds.

Between 2007/2008 sixty-eight intracapsular and fifty extracapsular hip fracture patients had serial haemoglobins and operative delays of >48 h (mean 75 h, range 48-270 h). The mean lowest recorded haemoglobin prior to surgery for both extracapsular and intracapsular fractures were 95.0 g/L (+/-SEM 2.2) and 108.5 g/L (+/-SEM 2.2) respectively. This difference was statistically significant (Student's t-test p<0.05). The mean haemoglobin drop in the extracapsular and intracapsular fracture groups was 20.2 g/L (range 0-49 g/L) and 14.9 g/L (range 0-59 g/L) respectively.

Hip fracture patients have a large drop in haemoglobin that is associated with the initial trauma rather than the operation. This highlights the need for anaesthetic and orthopaedic staff to be vigilant to the risk of pre-operative anaemia in this cohort of frail patients even when the initial haemoglobin is apparently normal.