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
Good example of why the CXR will always have a benefit in trauma- it gives a good overvew of the patient’s chest. Lung us and CXR should complement each other not replace each other
I complete agree Victoria ! Thanks for commenting….
I believe lung pulse is present on the left. But, stable pt with normal pulse ox, additional imaging is reasonable with unclear US findings, or even obvious pneumothorax. Lung pulse is another important finding to look for in cases of lung hypoventilation. Hypoventilation may come from splinting, mainstem intubation, bronchial obstruction, or other causes.
Thanks Joseph. I hadn’t actually considered the lung-pulse in this case.
Excellent points.
Cheers.
Hi Jacob, Chris – thanks for showing this one, I am always very cautious about diagnosing PNTX in trauma with LUS. I think we rule it in far too quickly. I would rule it out with LUS but not rule in unless crashing patient.
Just not so sure it is true lung pulse sign, because there is no extra movement below pleural line compared to above. Looks like the movement starts in the intercostals. Is tricky with the very sensitive straight probes which pick up all movement.
I also find that there sometimes seems to be a point of ‘non sliding’ very medial in anterior chest. Have demo pics somewhere down my FB page under ‘?double lung point’.