Assessment of Volume Status During Prone Spine Surgery via a Novel Point-of-care Ultrasound Technique

Abstract

Background Operations performed with the patient in the prone position can pose a significant challenge to the anesthesiologist. Hypotension is a commonly encountered complication. Intravascular volume depletion and decreased cardiac output secondary to decreased preload are thought to be the most likely cause of hypotension in the prone position. Measurement of inferior vena cava (IVC) diameter via point-of-care ultrasound examination (POC_US) has been used to provide an estimate of intravascular volume status. However, this measurement is most often obtained with the patient in the supine position. Materials and methods In this study, we describe a technique for evaluating IVC diameter via POC_US in the prone position. Right lateral long axis imaging of the IVC was used to assess the intravascular volume status of 10 patients undergoing lumbar spine surgery in the prone position. In addition, we used a non-invasive measure of cardiac output to correlate changes in IVC width with changes in cardiac output. Results Images of the IVC in the prone position were obtainable in all 10 patients. IVC diameter increased in six out of 10 patients on going from supine to prone position. The increase in IVC diameter corresponded to an increase in cardiac output, measured noninvasively in five out of the six patients. Conclusions Our findings indicate that POC_US examination of the IVC is possible in the prone position. Further study of a larger patient population could demonstrate the utility of this technique in assessing intravascular volume status in patients undergoing surgery in the prone position.

Description of the position and performance of an echocardiogram by subcostal view during the prone position in a patient with severe pneumonia caused by COVID-19

“… 2 3 A more favourable angle to evaluate the measurements of the inferior vena cava was also described, it tended to increase in size when passing from supine to prone and its compliance may contribute to the evaluation of the volume status in the prone position. 4–6 Previous researches described that apical views allowed the evaluation of ventricular and valve function. 3 6 7 A described position, where the patient’s left arm was raised and a pillow placed underneath the midthoracic wall to maintain the left hemithorax in a slightly elevated position, allowed only the apical view to be obtained.…”

Echocardiography and Multimodality Cardiac Imaging in COVID-19 Patients

“…[ 34 ] In such position, the posterior views may be used. In a normal condition, the aerated lung is a barrier to ultrasound and the heart is not visible, on the contrary, in the presence of a pleural effusion and/or of a lung consolidation, positioning the probe on the posterior left chest wall may allow to explore heart views;[ 35 ] moreover, from a right posterior view, the inferior vena cava diameter and collapsibility are easily explored,[ 36 ] [ Figure 3 ].…”

Novel 4W (When-Where-What-What) Approach of Training Point-of-Care Ultrasound (POCUS) Application in Resuscitation With High-Fidelity Simulator

“…Efficient resuscitation reduces morbidity and mortality and should be reflected in physician training for these scenarios. Point-of-care ultrasound (POCUS) has been successfully used in clinical settings for this purpose [2][3][4][5]. POCUS's implications in acute cardiopulmonary failure are uniquely advantageous by offering quick evaluations without resuscitation interference [6][7][8].…”