Non-invasive Stroke Volume-based fluid Management in Elderly Patients Undergoing Hip Fracture Surgery Under Spinal Anaesthesia

Non-invasive Stroke Volume-based fluid Management in Elderly Patients Undergoing Hip Fracture Surgery Under Spinal Anaesthesia

The study is going to be a single-centre prospective randomized trial. Patients will be randomly allocated to either control group (anesthetist-directed fluid therapy) or goal directed fluid therapy group, in which fluid therapy was guided by stoke volume (SV) algorithm with the use of Nexfin monitor. Primary outcome measures were the time to hospital discharge since surgery and the occurence of complications developed during the postoperative period. Secondary outcomes included the incidence of intraoperative hypotensive episodes (with MAP<65mmHg) in both groups and the requirement of vasoactive drugs to support blood pressure

The study is going to be a single-centre prospective randomized trial in elderly patients undergoing hip fracture surgery under spinal anesthesia.

Patients will be randomly allocated to either control group (anesthetist-directed fluid therapy) or goal directed fluid therapy group, in which fluid therapy was guided by stoke volume (SV) algorithm with the use of Nexfin monitor.

In patients of the control group management of the hemodynamic status will be performed in the discretion of the attending anesthesiologist, with the aim of keeping mean arterial pressure (MAP) > 65mmHg. The type and amount of delivered fluids, and vasoactive or inotropic drugs will be recorded.

In Goal Directed Fluid Therapy group, fluid management will be guided by the Nexfin monitor, based on stroke volume of the patient under continuous tracking. Baseline SV will be measured after the patients will be turned to left/right position (at which they are going to stay throughout the whole procedure) and before the implementation of regional anesthesia. Fluid challenges of 250 ml will be repeated until the SV fails to increase by 10%. At this point, preload is considered optimized and SV optimum iss defined. SV trigger is defined as SV opt - 10%. After obtaining these values, the anesthetic and surgical interventions could proceed. During surgery, N/S 250ml boluses will be administered when SV is below SV trigger. Inotropic drugs will be administered (dobutamine infusion at 0.2-10mcg/kg/min) if CO is below 3.5 L/min and vasopressors (phenylephrine bolus doses of 50-100mcg) if SV and CO are within the target range but MAP is below 65mmHg.

Primary outcome measures were the time to hospital discharge since surgery and the occurence of complications developed during the postoperative period. Secondary outcomes included the incidence of intraoperative hypotensive episodes (with MAP<65mmHg) in both groups and the requirement of vasoactive drugs to support blood pressure

Inclusion Criteria:

• Patients scheduled for hip fracture repair
• over 60 years of age
• American Society of Anesthesiologists (ASA) physical status II, III, IV

Exclusion Criteria:

• refusal or inability to consent,
• a plan for general anesthesia
• expected unreliable measurements of nexfin monitor (e.g. peripheral vascular disease, finger edema).