Air aspirated from the venous system during total hip replacement

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Medical Ultrasound

Background:

• Total hip replacement (THR) surgery can lead to significant hemodynamic changes.
• The presence and origin of air embolism during THR remain areas of investigation.

Purpose of the Study:

• To demonstrate the occurrence of air embolism during total hip replacement surgery.
• To investigate the potential source and timing of air embolism formation.

Main Methods:

• Ultrasound probe placed over the right atrium in six patients undergoing THR.
• Monitoring for changes in cardiac sound during femoral cementation and prosthesis insertion.
• Aspiration of air from the right atrium via catheter in four patients.

Main Results:

• An irregular rattling sound, indicative of air embolism, was detected in five of six patients during femoral cement hardening.
• This sound coincided with prosthesis insertion in two patients.
• Up to 3 ml of air was aspirated from the right atrium in four patients.

Conclusions:

• Air is likely formed in the venous system during femoral prosthesis insertion and cementation.
• This air embolism is a probable cause of transient circulatory and pulmonary impairment during THR.
• Recommendations include removing nitrous oxide (N2O) before cementation and considering right atrial catheterization to reduce risk.