Abstract
Introduction
Renal homeostasis has been shown to influence mortality after hip fractures; this is true for patients with both chronic kidney disease, and those who develop acute renal dysfunction after surgery. We have examined the influence of impaired renal function upon mortality and length of stay. We investigated this relationship through accurate mathematical modelling of available biochemistry data on a cohort of hip fracture patients.
Methods
Complete data were available for 566 patients treated over a 27-month period. All patients had urea and creatinine checked on admission, and at 24–48 hours after surgery. Post-operative analgesia, fluid therapy, transfusion protocols and orthogeriatric reviews were standardised. Generalised Linear Models and correlation matrices were used. Cox-proportional hazards analyses investigated the association between serum concentrations of urea and creatinine on admission and length of stay and mortality after surgery.
Results
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The cohort included 427 females and 139 males (mean age 80.6 years, mean post-operative length of stay 19 days). 1-year mortality was 19.1%.
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Urea and creatinine were significantly, positively correlated with age (more significant for urea).
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After adjusting for age and sex, risk of mortality was positively related to serum concentrations of creatinine and marginally so for urea.
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Increased age and a male gender were associated with a higher mortality risk
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Risk of discharge from trauma ward, length of stay on trauma ward, and overall length of stay were not related to levels of creatinine and urea at admission.
Conclusions
This study shows a quantifiable correlation between renal dysfunction and NOF mortality. The low risk of survival with both male sex and raised creatinine identified this subgroup as the ‘most at risk’. Both age and gender are non-modifiable factors, so this subgroup may require a more targeted approach to the management of their fluid and electrolyte homeostasis.
