John Hermez
A 74 year-old male with a past medical history of metastatic castration-resistant prostate cancer complicated by cauda equina necessitating laminectomy decompression, chronic RLE DVT on apixaban and chronic hypotension presented to the emergency department accompanied by his spouse for altered mental status. Per the patient’s wife, he experienced cognitive decline and increasing weakness for one week prior to presentation. Two days prior to his arrival in the ED, the patient became more confused and agitated with his wife reporting that he appeared to be hallucinating intermittently. While he typically ambulates without assistance and straight-catheterizes himself, he has been unable to care for himself independently.
Vitals: BP 91/53 | Pulse 85 | Temp 98.1 °F (36.7 °C) | Resp 12 | Wt 92.3 kg (203 lb 7.7 oz) | SpO2 98% | BMI 29.1 kg/m²
Physical Exam:
On exam, the patient is in no acute distress and is oriented only to his name. He has diffuse anasarca with 2+ right lower extremity edema and 1+ left lower extremity edema. He is not pale or cyanotic and has shallow respirations on room air with diminished lung sounds and a flat JVP.
Labs: WBC 25.7 and initial lactate 2.2. Hb 9.5 PLT 98, Urine cloudy and orange, growth pending
ECG: NSR at 82 bpm with occasional PVCs, no evidence of ST changes
CXR: Compared to prior, there are new heterogenous bibasilar lung opacities and atelectasis possibly representing pneumonia. No definite pleural effusion or pneumothorax. Stable cardiac silhouette.
To clarify cardiac function and better characterize pulmonary status, a bedside point of care echocardiography was performed.

Figure 1: Trace pericardial effusion seen on parasternal short axis view.
Figure 2: Sagittal right sview demonstrating the thoracic spine sign
Discussion:
Radiographic imaging of the thorax is routinely performed in the ED to aid in the diagnosis of a wide range of cardiopulmonary manifestations. While upright chest x-rays are the Gold Standard for detecting pneumonia in patients, the detection of pleural effusion may be less clearly visualized. Meta-analysis has shown that the screening sensitivity of ultrasound may be 94% as compared to 51% for chest x-ray, in spite of having similar specificity.1 In this case, we rapidly obtained a point-of-care echocardiogram and pulmonary ultrasound to guide medical decision making in a patient with advanced metastatic disease and anasarca with equivocal radiograph.
A parasternal short axis view was obtained (figure 1) and demonstrated a trace pericardial effusion estimated to be 3mm without evidence of gross systolic dysfunction. Although the right ventricle was poorly visualized during diastole, the small volume of effusion and history of chronic hypotension was reassuring against tamponade physiology. Acquisition of a right subcostal view (figure 2) demonstrated the thoracic spine sign which is a reliable indicator of pleural effusion or hemothorax.2

Figure 3: Subcostal view labelled to identify anechoic pleural effusion (image courtesy of Stanford Medicine 25)5
The spine sign is a sonographic description of the visualization of vertebral bodies above the level of the diaphragm, which indirectly indicates that a thoracic fluid collection is present. When there is no thoracic free fluid present, an abrupt loss of the vertebral bodies occurs at the diaphragm due to air in the lungs impeding transmission.2 Pleural effusions and traumatic hemothorax can both represent fluid collections, hence the utility of subcostal imaging in the eFAST exam to evaluate thoracic trauma. One study on closed chest trauma has shown the absence of the spine sign to have a negative predictive value of 97.8% in assessing pleural effusion.3 The focused use of ultrasonography in the emergency department is regarded of high value in the early detection and diagnosis of multiple pathologies. Algorithmic exams such as the RUSH protocol provide rapid feedback on the physiology of a critically ill patient which can guide management and are recommended both by the American College of Emergency Physicians and Critical Care Societies.4 The potential applications of ultrasonography in resource-limited, austere environments by prehospital personnel are also of particular interest given novel advancements in AI-technology and focused training protocols.
In spite of a technically challenging exam, this case was an excellent example of the utility of multimodal imaging to clarify cardiopulmonary status in the ED. The patient was treated with broad antibiotic therapy for suspected urosepsis and admitted to the hospital for multidisciplinary care. He later was scheduled for therapeutic thoracentesis and surgical evaluation for a scapular fluid collection.
References:
- Yousefifard M, Baikpour M, Ghelichkhani P, Asady H, Shahsavari Nia K, Moghadas Jafari A, Hosseini M, Safari S. Screening Performance Characteristic of Ultrasonography and Radiography in Detection of Pleural Effusion; a Meta-Analysis. Emerg (Tehran). 2016 Winter;4(1):1-10. PMID: 26862542; PMCID: PMC4744606.
- Dickman, E., Terentiev, V., Likourezos, A., Derman, A. and Haines, L., 2015. Extension of the Thoracic Spine Sign: A New Sonographic Marker of Pleural Effusion. Journal of Ultrasound in Medicine, 34(9), pp.1555-1561.
- Vargas CA, Quintero J, Figueroa R, Castro A, Watts FA. Extension of the thoracic spine sign as a diagnostic marker for thoracic trauma. Eur J Trauma Emerg Surg. 2021 Jun;47(3):749-755. doi: 10.1007/s00068-020-01459-1. Epub 2020 Aug 17. PMID: 32803497.
- Seif D, Perera P, Mailhot T, Riley D, Mandavia D. Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol. Crit Care Res Pract. 2012;2012:503254. doi: 10.1155/2012/503254. Epub 2012 Oct 24. PMID: 23133747; PMCID: PMC3485910.
- “The Spine Sign.” Edited by Stanford Medicine 25 Bedside Medicine Symposium, Stanford Medicine 25, Stanford Medicine 25 Bedside Medicine Symposium, stanfordmedicine25.stanford.edu/blog/archive/2018/thespinesign1.html. Accessed 25 May 2025.