Robert Jones, DO Profile picture
EM | POCUS | Asst Dean Clerkship Education- MHMC/Case | Opinions are mine | RTs not endorsements I Case hx all changed to de-identify

Jan 13, 2022, 16 tweets

Management if patient was tachypneic/hypotensive based on CXR?

This was a skin fold which can mimic PTX on CXR. POCUS and ultimately CT scan to assess for other traumatic injuries were negative for findings of PTX. Old case so I don't have POCUS clips but was normal.

If you look closely at the chest X-ray you can see lung markings peripheral to the fold, the line extends caudal to lung border, and the absence of the white line sign. Don't confuse skin fold with PTX. Skin fold aside, how good is supine CXR for PTX?

Supine CXR common in critical med/surg patients. Poor sensitivity for PTX. 50+% false negatives! Here is Cochrane review comparing CXR vs POCUS. ncbi.nlm.nih.gov/pmc/articles/P…

Thoracic ultrasound highly sensitive and specific. Absence of lung sliding (shown) is highly suggestive of PTX-but not definitive for diagnosis.

Here is lung sliding. Remember this is not a qualitative assessment. It is an all-or-none.

For thoracic POCUS you can use any probe. Settings are important. Focus zone at pleural line, turn off harmonics and compound imaging, and increase gain in far field--will improve visualization of B lines (and potentially lung sliding) onlinelibrary.wiley.com/doi/10.1002/ju…

Lung point is the definitive sonographic finding for PTX. Shown here. This is where you have the PTX abutting with the opposed parietal and visceral pleura.

Due to the high sensitivity, you can even see very small pneumothoraces---Double lung point (2 lung points). For peds POCUS users, different from your double lung point used to diagnose TTN.

Power of Thoracic Ultrasound. Here is lung re-expansion after placement of pigtail catheter seen real-time.

I feel Thoracic u/s is particularly useful in supine patients, critically ill pts, those with abnormal CXRs, COVID-19 in isolation, and post thoracic procedures. Here is patient with no so normal CXR and sudden onset dyspnea--?PTX.

Thoracic POCUS showed lung sliding throughout along with evaluating for pleural effusions and pleural patterns.

What about patients with bullae and a non-diagnostic CXR for PTX? Thoracic ultrasound has been shown to be very useful here in differentiating between the two with the evaluation of lung sliding. Sens 97.5% and Spec 100% pubmed.ncbi.nlm.nih.gov/30178311/

Meant not a quantitative assessment---All-or-none

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