the case.
an elderly male is bought to ED following a high-speed motor vehicle accident having driven his car into a tree at ~100 km/h. He is complaining of severe chest pain & trouble breathing.
Primary survey:
A. Patent & protected. C-spine immobilised.
B. RR 20. SaO2 99%. Symmetrical chest movement but reduced left-sided air entry. No subcutaneous emphysema.
C. P 100/min. BP 146/80. Warm & perfused. No active bleeding.
D. GCS 15. PEARL (4mm). Moving all 4 limbs.
E. Afebrile. BSL 8. Swollen, deformed LEFT ankle.
You perform your EFAST exam. (There is NO free-fluid in the abdomen & the pericardial view is normal).
2D lung ultrasound: Preservation of pleural sliding with presence of comet-tail artefact – ie. no pneumothorax.
M-mode ultrasound of right chest. Seashore sign present (ie. no pneumothorax).
2D lung ultrasound: Poorly visualised lung sliding. No comet-tail artefacts. Highly suspicious for pneumothorax.
M-mode ultrasound: Stratosphere (bar-code) sign suggestive of pneumothorax.
Are you going to place a chest drain on this information ?
Do you get his CT first ??
Would would you do ???
Mobile CXR: marked left upper lobe opacification with distortion of the nearby mediastinal structures.
This CXR could easily be explained by a traumatic blunt aortic injury, especially given the mechanism of action. The patients overall clinical picture & haemodynamic stability however, made this less likely.
It was at this point that the patients’ wife arrived to explain that he had recently been diagnosed with a left-sided lung cancer which was inoperable.
False positive pneumothorax
I have previously posted on FALSE POSITIVE FAST EXAMS with respect to the abdominal component of the study.
Firstly; some quick revision…
MAKING the DIAGNOSIS of PNEUMOTHORAX on ULTRASOUND.
Requires the following three steps.
- abolished lung sliding
- stratosphere (bar-code) sign on M-mode
- presence of a lung point
CAUSES of FALSE POSITIVE PNEUMOTHORAX.
- Bullous lung disease
- Main-stem bronchial intubation
- Inflammatory adherence.
- ARDS
- Pleurodesis
- Pulmonary contusion/consolidation
- Atelectasis
- Severe pulmonary fibrosis
- Phrenic nerve palsy
Check out this great review on Ultrasound for Pneumothorax at R.E.B.E.L EM…
- Volpicelli, G., Elbarbary, M., Blaivas, M., Lichtenstein, D. A., Mathis, G., Kirkpatrick, A. W., et al. (2012). International evidence-based recommendations for point-of-care lung ultrasound. Intensive care medicine, 38(4), 577–591. doi:10.1007/s00134-012-2513-4
- Lichtenstein, D. A. (2014). Lung ultrasound in the critically ill. Annals of intensive care, 4(1), 1. doi:10.1186/2110-5820-4-1
- Zhang, M., Liu, Z.-H., Yang, J.-X., Gan, J.-X., Xu, S.-W., You, X.-D., & Jiang, G.-Y. (2006). Rapid detection of pneumothorax by ultrasonography in patients with multiple trauma. Critical care (London, England), 10(4), R112. doi:10.1186/cc5004
- Nandipati, K. C., Allamaneni, S., Kakarla, R., Wong, A., Richards, N., Satterfield, J., et al. (2011). Extended focused assessment with sonography for trauma (EFAST) in the diagnosis of pneumothorax: experience at a community based level I trauma center. Injury, 42(5), 511–514. doi:10.1016/j.injury.2010.01.105lhop
- Slater, A., Goodwin, M., Anderson, K. E., & Gleeson, F. V. (2006). COPD can mimic the appearance of pneumothorax on thoracic ultrasound. Chest, 129(3), 545–550. doi:10.1378/chest.129.3.545
Leave a Reply