The cortisol stress response following surgery for proximal femur fractures in geriatric patients – a prospective pilot study

Introduction: Aging impairs the suprachiasmatic nucleus function, compromising the adrenocortical circadian rhythmicity and, potentially, affecting the cortisol stress response. Relative cortisol insufficiency may contribute to peri- and postoperative complications and increase mortality. While proximal femoral fractures in geriatric patients are among the most common musculoskeletal injuries, little is known about the adrenal stress response in geriatric patients undergoing surgery for this injury. Methods: The present prospective pilot study investigated the postoperative cortisol levels in 20 geriatric patients (age > 70 years) with proximal femur fractures who were admitted to the intensive care unit (ICU) of a level I trauma center. Cortisol levels were obtained by blood sampling after surgery in conjunction with daily routine laboratory examinations. Further data acquisitions included demographic information as well as surgery and ICU stay related characteristics. Results: The results showed that 35% of all patients demonstrated cortisol levels even below the basal threshold of 276 nmol/L, which is commonly used for the definition of critical illness-related corticosteroid insufficiency (CIRCI). Correlation analysis revealed a significant association between interleukin-6 (IL-6) and cortisol levels, whereas procalcitonin (PCT), leukocyte count and C-reactive protein (CRP) had no predictive value. A considerable proportion of geriatric trauma patients suffering from proximal femoral fractures admitted to the ICU exhibited lower-than-expected cortisol levels. Conclusion: Postoperative determination of cortisol levels should be considered in geriatric patients undergoing postoperative monitoring. This would allow to identify patients with an attenuated cortisol stress response and enable timely initiation of treatment, such as probatory administration of hydrocortisone, to improve patient outcome. Moreover, IL-6 may represent a potential marker for the monitoring of the postoperative endocrine stress response in geriatric trauma patients.