Comparison of fractionated dose versus bolus dose injection in spinal anaesthesia in elderly patients undergoing femur fracture surgery – A randomized double-blind study

The geriatric population, irrespective of the type of surgery they undergo, poses a challenge for the anaesthesiologists. This is attributed to the reduced functional reserve in the elderly, associated multiple comorbidities and frail nature. Elderly patients with femur fractures usually add to this challenge as they may present late to the hospital for their treatment, which increases the risk of perioperative adverse outcomes. Generally, spinal anaesthesia (SA) is commonly employed for lower limb surgeries. Its advantages are simple to perform, good analgesia, reduced blood loss and so on. But the sympatholysis produced by spinal anaesthesia when given as a bolus dose of local anaesthetics can lead to profound hypotension, which may not be tolerated by the elderly patients. This hypotension can predispose patients to have end organ damage, which contributes to the overall morbidity. Rate of injection is one of the factors determing the level of spinal block and incidence of hypotension. Fractionated dose of local anaesthetic in spinal anaesthesia is administering two-thirds of the total calculated dose initially following which the remaining one-third dose is given after a gap of 45 to 90 sec between the injections. This method has been shown to provide better hemodynamic stability and longer duration of analgesia.