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

BACKGROUND: Approximately 70,000 patients/year undergo surgery for repair of a fractured hip in the United Kingdom. This is associated with 30-day mortality of 9% and survivors have a considerable length of acute hospital stay postoperatively (median 26 days). Use of oesophageal Doppler monitoring to guide intra-operative fluid administration in hip fracture repair has previously been associated with a reduction in hospital stay of 4-5 days. Most hip fracture surgery is now performed under spinal anaesthesia. Oesophageal Doppler monitoring may be unreliable in the presence of spinal anaesthesia and most patients would not tolerate the probes. An alternative method of guiding fluid administration (minimally-invasive arterial pulse contour analysis) has been shown to reduce length of stay in high-risk surgical patients but has never been studied in hip fracture surgery. METHODS: 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.