The use of LiDCO based fluid management in patients undergoing hip fracture surgery under spinal anaesthesia: Neck of femur optimisation therapy - targeted stroke volume (NOTTS): study protocol for a randomized controlled trial

Single-centre randomised controlled parallel group trial. Randomisation by website using computer generated concealed tables. Setting: University hospital in UK. Participants: 128 patients with acute primary hip fracture listed for operative repair under spinal anaesthesia and aged > 65 years. Intervention: Stroke volume guided intra-operative fluid management. Continuous measurement of SV recorded by a calibrated cardiac output monitor (LiDCOplus). Maintenance fluid and 250 ml colloid boluses given to achieve sustained 10% increases in stroke volume. Control group: fluid administration at the responsible (blinded) anaesthetist's discretion. The intervention terminates at the end of the surgical procedure and post-operative fluid management is at the responsible anaesthetist's discretion. Primary outcome: length of acute hospital stay is determined by a blinded team of clinicians. Secondary outcomes include number of complications and total cost of care.Funding NIHR/RfPB: PB-PG-0407-13073.Trial registration: Current Controlled Trials ISRCTN88284896.Approximately 70,000 patients per year undergo surgery for repair of a fractured hip in the United Kingdom (UK) [1], at a cost of ￡25,424 per patient [2]. Hip fracture is associated with a high mortality (approximately 9% at 30 days postoperatively)[3] and a considerable length of acute hospital stay (median stay 26 days) [4]. Mortality and length of stay in hospital have remained relatively constant over recent years. The majority of patients with hip fracture are elderly women (median age 81 years, 73% female) [2], and the number of these patients will likely increase in the future in line with the changes in the United Kingdom population [5-7].Patients with hip fracture suffer from a variety of fluid losses following their injury. They spend a variable amount of time unable to drink or eat, due to immobility at the time of injury and fasting prior to surgery. The fracture itself will haemorrhage internally to a variabl