Pre-operative Anemia and Hyponatremia Increase the Risk of Mortality in Elderly Hip Fractures

Objectives: Pre-operative assessment is routinely performed for all hip fractures, and include a thorough clinical examination and multiple pre-operative tests. While abnormalities are often detected in many tests, they have varied effect on mortality. The purpose of the study was to assess the prevalence and impact of these abnormal tests and comorbidities. Methods: This was a prospective study of 283 consecutive hip fracture patients aged above 50 years admitted in a major trauma hospital from February 2019 to December 2019. The prevalence of abnormalities in the following tests were assessed: chest x-ray, electrocardiogram, complete blood count, serum electrolytes, renal function test, prothrombin time/international normalized ratio, and serum bilirubin. Also, presence of comorbidities were recorded. Mortality within 90 days of admission was assessed. Results: 91.5% (N= 259/283) of the patients had at least one abnormal investigation. The most common abnormal investigation was anemia (70.3%, N= 199/283), followed by deranged sodium (36.4%, N= 103/283). 17.7% (N= 50/283) of the patients had at least one new comorbidity diagnosed after admission. The most common newly diagnosed comorbidity was hypertension (10.6%, N= 30/283). Anemia (p=0.044), deranged sodium (p=0.002), raised urea (p=0.018), raised creatinine (p=0.002), renal disease (p=0.015), neurological diseases (p=0.024), and charlson comorbidity index (p=0.004) were associated with increased mortality in multivariate analysis. Conclusion: Pre-operative hemoglobin, sodium, urea, and creatinine were the most important tests influencing mortality, and derangements of these should therefore be carefully evaluated and managed. Hip fracture care pathways should focus on correction of these abnormalities. Level of evidence: II