The effect of time to surgery in neck of femur fracture patients with ASA Grade of 3 and above

Abstract

Introduction: Hip fractures are an important cause of morbidity and mortality. Early surgery has been shown to reduce mortality rates and surgical complications. The American Society of Anesthesiologists (ASA) grade is a widely used tool to assess preoperative health of patients. This study aims to assess is whether delay in surgical time has a greater impact on the mortality rates for high risk patients. Method: Retrospective study using the National Hip Fracture Database (NHFD) of 4883 neck of femur fracture patients. Time of surgery, ASA grade, reason for delay and mortality at 120 days was analysed, using statistical analysis software. Results: There was a significant increase in mortality ( p < 0.001) with increasing ASA grade. Surgical delays of more than 36 hours increased mortality by 2.9%. The impact of delaying surgery became more pronounced as the ASA grade increased. ASA 3 and above had an optimum time to surgery of between 12 and 24 hours giving the statistically significant lowest mortality rate ( p = 0.004). Discussion: Surgical delay beyond the 36-hour target for surgery has a greater impact on mortality for patients with higher ASA grades. The effect is most profound in the high-risk ASA grade 5 patients with delayed patients showing a 37.5% increase in mortality in this group. This would imply that by prioritising this higher risk group and operating on it within a specific time frame there would be a subsequent fall in mortality associated with neck of femur fractures.