Diminished Renal Function in Patients with Femoral Neck Fractures: Who is in Risk?

Background: Elderly patients with hip fractures are prone to higher unexplained mortality. While patients with diminished kidney functions are at increased risk to develop hip fractures, which also harbor increase mortality rate in these patients. Nonetheless, the true causation for such mortality is still unknown. In this study we set out to find whether initial diminished renal function or deterioration during hospitalization is linked to peri and intraoperative parameters including mortality.

Patients and Methods: 755 geriatric participants who were operated in our department and had serum creatinine measured at baseline, immediately prior to surgery and prior to discharge were included in this study. Initial Estimated glomerular filtration rate (eGFR) was derived from the modification of diet in renal disease formula (MDRD) for estimation of kidney function. The RIFLE criteria ware derived from the Acute Dialysis Quality Initiative (ADQI) for estimation of acute injury using eGFR and serum creatinine to classify the level of renal dysfunction. Peri-operative parameters included time to surgery, anesthesia and operative time, anesthesia type, blood transfer requirements, length of hospitalization and mortality (one year). The Highest level of creatinine was also noted.

Results: The average age was 81.2, with 35.6% of the patient’s male. The mean theater time was 1 hour and 32 minutes while operative time was 49 minutes. 23.3% patients died within follow-up period. 21.3% patients had intact renal failure (stage 1), while 40% had stage 2, 29.1% had stage 3, 4.4% had stage 4 and only 1.9% had end stage renal failure. 39.5% of patients worsened their kidney failure stage throughout hospitalization. Only 11.8% have been discharged with decreased renal function

Although initial renal failure did not affect type of anesthesia, length of theater stay and operative type, It did dictate increased use of blood products throughout hospitalization (P<0.001). Advance initial renal failure stage was also associated with increased mortality, peaking at 35.7% in the stage 5 population (P<0.001). Of note, patients with acute kidney injury recorded during hospitalization reached an even higher rate of 50% mortality (P<0.001)

Conclusion: Impaired renal failure is a prognostic factor for the survival of geriatric patients, but does not significantly influence surgical and anesthesia parameters. Patients with advance renal disease are more prone to require blood units and should therefore be monitored accordingly. Adequate hydration throughout hospitalization should be sought in more aggressive manner, since elevated creatinine levels substantially increased mortality.