A randomised trial of non-invasive cardiac output monitoring to guide haemodynamic optimisation in high risk patients undergoing urgent surgical repair of proximal femoral fractures (ClearNOF trial NCT02382185)

Background: Hip fracture is a procedure with high mortality and complication rates, and there exists a group especially at risk of these outcomes identified by their Nottingham Hip Fracture Score (NHFS). Meta-analysis suggests a possible benefit to this patient group from intravascular volume optimisation. We investigated whether intraoperative fluid and blood pressure optimisation improved complications in this group. Methods: Patients with a NHFS ≥ 5 were enrolled into this multicentre observer-blinded randomised control trial. Patients were allocated to either standard care or a combination of fluid optimisation and blood pressure control using a non-invasive system. The primary outcome was the number of patients with one or more complications in each group. Secondary outcomes included hospital length of stay (LOS), incidence of hypotension and fluid and vasopressor usage. Results: Forty-six percent of patients in the intervention group suffered one or more complications compared to the 51% in the control group (OR 0.82 (95% CI 0.49-1.36)). Per-protocol analysis improved the OR to 0.73 (95% CI 0.43-1.24). Median LOS was the same between both groups; however, the mean LOS on a per-protocol analysis was longer in the control group compared to the intervention group (23.2 (18.0) days vs. 18.5 (16.5), p = 0.047). Conclusions: Haemodynamic optimisation including blood pressure management in high-risk patients undergoing repair of a hip fracture did not result in a statistically significant reduction in complications; however, a potential reduction in length of stay was seen. Trial registration: A randomised trial of non-invasive cardiac output monitoring to guide haemodynamic optimisation in high risk patients undergoing urgent surgical repair of proximal femoral fractures (ClearNOF trial NCT02382185).