Pulmonary and circulatory reactions during total hip replacement surgery

Area of Science:

• Anesthesiology
• Cardiopulmonary Physiology
• Orthopedic Surgery

Background:

• Total hip replacement (THR) involves surgical implantation of acetabular and femoral prostheses.
• Anesthesia and ventilation strategies may influence patient responses during THR.
• Understanding perioperative cardiopulmonary changes is crucial for patient safety.

Purpose of the Study:

• To investigate pulmonary and circulatory reactions during THR surgery.
• To evaluate the impact of ventilatory patterns on these reactions.
• To identify specific surgical events triggering significant physiological alterations.

Main Methods:

• Studied 22 osteoarthrosis patients undergoing THR under lumbar epidural analgesia.
• Divided patients into two groups: spontaneous air breathing (Group A, n=15) and controlled ventilation (Group B, n=7).
• Monitored pulmonary and circulatory parameters, focusing on reactions to prosthesis insertion.

Main Results:

• Femoral prosthesis impaction caused significant increases in pulmonary venous admixture and pulmonary vascular resistance.
• Arterial oxygen tension and mean pulmonary arterial pressure decreased significantly post-impaction.
• Transient systemic arterial pressure decrease and pulmonary arterial pressure rise were observed, with no significant changes in cardiac output or other measured parameters.

Conclusions:

• Femoral prosthesis impaction induces transient pulmonary vascular and airway constriction, leading to ventilation/perfusion disturbances and decreased arterial oxygen tension.
• Peripheral vasodilatation occurs, causing a transient drop in systemic arterial pressure.
• The findings highlight the need for careful monitoring of cardiopulmonary status during THR, particularly during prosthesis impaction.