Ultrasound monitoring to detect embolic phenomena in the inferior vena cava during hip arthroplasty.

INTRODUCTION AND OBJECTIVES: Embolic phenomena frequently occur during hip joint replacement surgery, and may lead to haemodynamic instability in frail patients. Transoesophageal ultrasound monitoring is rarely available in non-cardiac operating theatres, and cannot be performed in awake patients under spinal anaesthesia. The main objectives of this prospective exploratory study were to determine the feasibility of using an alternative ultrasound approach to monitor the inferior vena cava during hip replacement surgery, and to determine the intra and interobserver reliability of the ultrasound findings. METHOD: We conducted a prospective exploratory study in 20 patients undergoing cemented hip arthroplasty in the supine position under spinal anaesthesia and sedation. The inferior vena cava was assessed through a subcostal window at 10 intraoperative time points, and the findings were rated on a qualitative embolism severity scale. The ultrasound images were evaluated by 2 independent observers. RESULTS: An adequate subcostal window was obtained in 90% of cases. Intra- and inter-observer reliability was high (kappa index >0.80, p < 0.001). Nearly all (95%) patients presented some degree of embolism, which was severe in 50% of cases. CONCLUSIONS: Our study suggests that ultrasound assessment of embolic phenomena in the inferior vena cava through a subcostal window is feasible in 90% of cases. The qualitative embolic severity rating scale is highly reproducible and has high intra- and inter-observer reliability.