change in surgical technique (lateral approach vs anterior approach for hip arthroplasty, determining a change in patient intraoperative positioning)

Patients undergoing elective primary total hip replacement and spinal anesthesia may encounter significant hemodynamic instability.

The study is a randomized controlled type and is aimed at comparing how perioperatory hypotension and fluid regimen are managed using Clearsight non invasive monitoring system or PAM monitoring.

The primary endpoint is to evaluate total duration of hypotension, defined as a MAP < 65 mmHg, calculated during all the perioperatory time.

Fifty-eight patients, aged 50-80 years, with an American Society of Anaesthesiologists' (ASA) score I, II and III were enrolled and split in two groups (Clearsight and control group). Patients were monitored both with the EV1000 platform, the Clearsight finger-cuff and MAP monitoring. Depending on the group, the fluid regimen was a goal directed fluid therapy or a liberal fluid regimen.

Inclusion Criteria:

• Age 50-80 years
• ASA I, II or III
• primary elective hip arthroplasty

Exclusion Criteria:

• spinal anesthesia contraindications
• periferical vasculopaty
• other diseases which indicates better an invasive monitoring by radial artery cannulation
• atrial fibrillation
• denial or inability to provide informed consent