Serum Lactate is a Prognostic Indicator in Patients with Hip Fracture

Abstract

Background and Purpose Serum lactate has been shown to be an indicator of adverse clinical outcomes in patients admitted secondary to general trauma or sepsis. We retrospectively investigated whether admission serum venous lactate can predict in-hospital mortality in patients with hip fractures. Method and Results Over a 38-month period the admission venous lactate of 807 patients with hip fractures was collated. Mean age was 82 years. The overall in-hospital mortality for this cohort was 9.4%. Mortality was not influenced by the fracture pattern or the type of surgery - be it internal fixation or arthroplasty (p = 0.7). A critical threshold of 3 mmol/L with respect to the influence of venous lactate level on mortality was identified. Mortality rate in those with a lactate level of less than 3 mmol/L was 8.6% and 14.2% for those whose level was 3 mmol/L or greater. A 1 mmol/L increase in venous lactate was associated with a 1.2 (1.02–1.41) increased risk of in-hospital mortality. Patients with a venous lactate of 3 mmol/L or higher had twice the odds of death in hospital compared to matched individuals. There was no statistically significant difference in ASA distribution between those with a lactate of less than or greater than 3 mmol/L. Conclusions Patients with an elevated venous lactate following hip trauma should be identified as being at increased risk of death and may benefit from targeted medical therapy.