Study of Blood Volume and Fluid Changes During Total Hip Replacement Surgery Using Non-Invasive Carbon Monoxide Rebreathing

What this Trial Is About

Researchers are studying changes in blood volume and fluid distribution around the time of surgery in patients undergoing total hip replacement. The study aims to better understand how blood volume changes during this surgery and how these changes relate to the occurrence of orthostatic intolerance, which is difficulty standing up without dizziness or fainting. This observational study uses a non-invasive carbon monoxide rebreathing method to measure blood volume accurately, as traditional assessments may not provide precise estimates. Participants will undergo carbon monoxide rebreathing measurements before surgery, and at 6 and 24 hours after surgery to track changes in total blood volume, hemoglobin, erythrocyte volume, plasma volume, and fluid distribution inside and outside cells. The study also measures inflammation markers like C-Reactive Protein and monitors orthostatic intolerance during mobilization after surgery. These measurements help describe how the bodys fluid and blood volumes shift during and after hip replacement surgery. During the study, participants will be assessed before surgery and at two postoperative times for blood volume and fluid changes, inflammation, and symptoms related to standing up. Researchers will analyze the association between blood loss and orthostatic intolerance, as well as inflammation and peripheral blood flow. The primary outcome is the change in total blood volume from before surgery to 6 hours after. Participants are involved only during the perioperative period, with all measurements conducted in the hospital setting.

Changes in Perioperative Blood Volume and Fluid Distribution in Patients Undergoing Primary Total Hip Replacement.