Inferior vena cava ultrasonography in the assessment of intravascular volume status and fluid responsiveness in the emergency department and intensive care unit: A critical analysis review

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.

Point of care transthoracic echocardiography for the prediction of post - spinal anesthesia hypotension in elderly patients with cardiac diseases and left ventricular dysfunction : Inferior vena cava and post-spinal anesthesia hypotension in elderly patients

In elderly patients with cardiac diseases, changes in cardiovascular physiology diminish cardiovascular reserve and predispose to hemodynamic instability after spinal anesthesia; hence, such patients could be at risk of postoperative complications. Additionally, transthoracic echocardiography (TTE) is used in clinical practice to evaluate cardiovascular hemodynamics. Therefore, we hypothesized that echocardiographic measurements could display significant diagnostic power in the prediction of post - spinal anesthesia hypotension in elderly patients with cardiac diseases and reduced left ventricular ejection fraction (LV-EF). Therefore, sixty-one elderly orthopedic-trauma patients were recruited. Prior to spinal anesthesia a TTE examination was performed. The LV-EF, the stroke volume index (SVI), the peripheral vascular resistance (PVR), the LV filling pressures (E/Em ratio), the right ventricular function [tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (TASV) and fractional area change (FAC)], as well as inferior vena cava (IVC) measurements, such as IVCCI (collapsibility index of the IVC) and dIVCmax (maximum diameter of IVC)-to-IVCCI ratio were assessed. Twenty-six out of sixty-one patients manifested hypotension. Preoperative dIVCmax-to-IVCCI ratio demonstrated the greatest performance amongst echocardiographic indices in predicting post - spinal anesthesia hypotension. The dIVCmax-to-IVCCI ratio < 48 had significantly higher diagnostic power than IVCCI > 0.28, FAC > 42, E/Em ratio < 9 and SVI < 32 (receiver operator characteristic curve analysis). The gray zone for the dIVCmax-to-IVCCI ratio (40-49) showed the lowest number of inconclusive measurements among echocardiographic variables. The preoperative dIVCmax-to-IVCCI ratio could be a reliable echocardiographic index to predict post - spinal anesthesia hypotension in elderly patients with left ventricular dysfunction.