Hip Fracture Intervention Study for Prevention of Hypotension Trial: a Pilot Randomized Controlled Trial

Abstract

Background: Hypotension during anesthesia for surgery for hip fracture is common and associated with myocardial injury, stroke, acute kidney injury, and delirium. We hypothesized that maintaining intraoperative blood pressure close to patients' preoperative values would reduce these complications compared to usual care.

Methods: A pilot feasibility patient- and assessor-blinded parallel group randomized controlled trial. People with unilateral hip fracture aged ≥70 years with capacity to give consent before surgery were eligible. Participants were allocated at random before surgery to either tight blood pressure control (systolic blood pressure ≥80% preoperative baseline and mean arterial blood pressure ≥75 mm Hg) or usual care. Feasibility outcomes were protocol adherence, primary outcome data completeness, and recruitment rate. The composite primary outcome was myocardial injury, stroke, acute kidney injury or delirium within 7 days of surgery.

Results: Seventy-six participants were enrolled, and 12 withdrew before randomization. Sixty-four participants were randomized, 30 were allocated to control, and 34 to intervention. There was no crossover, all 64 participants received their allocated treatment, primary outcome was known for all participants. The composite primary outcome occurred in 14 of 30 participants in the control group compared with 23 of 34 participants in the intervention group (P = .09), relative risk 1.45 (95% confidence interval [CI], 0.93-2.27).

Conclusions: A randomized controlled trial of tight intraoperative blood pressure control compared to usual care to reduce major postoperative complications after fractured neck of femur surgery is possible. However, the data would suggest a large sample size would be required for a definitive trial.

Figure 1.

CONSORT diagram of participant enrollment, allocation and follow-up. CONSORT indicates Consolidated Standards of Reporting Trials.

Figure 2.

Relative change in blood pressure during hip fracture surgery for participants allocated to tight blood pressure control (orange) or usual care (blue). Mean pressures by group allocation are shown as solid lines. MAP indicates mean arterial pressure; SBP, systolic blood pressure.

Figure 3.

Kaplan-Meier plot for 1 y survival for participants allocated to tight blood pressure control (orange) or usual care (blue).