Non-COVID #pulmonary teaching: a young man recently diagnosed with asthma comes to clinic with progressive dyspnea on exertion. Despite treatment with an inhaled corticosteroid (ICS) & short acting bronchodilator (SABA), he feels worse. CXR & spirometry are shown. #FOAMed 1/
What would you like to do next?
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The key to this case is recognizing a distinctive abnormality in the flow-volume loop, specifically the truncation of both the inspiratory & expiratory flows.
This is characteristic of a fixed obstruction, which can occur with external compression or stenosis of the trachea. 3/
Now back to our patient - what could be causing his obstruction?
Let’s inquire about B-symptoms (malignancy) and symptoms of hyper/hypothyrodism. We can also ask about prior intubations (a cause tracheal stenosis) or other past airway issues.
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A careful physical exam can also help diagnose a tracheal obstruction; in contrast to asthma
* wheezing may loudest over the central chest or neck
* wheezing may be polyphonic instead of monophonic
For example:
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A careful thyroid & LN exam may identify abnormalities, in this case an asymmetric enlarged thyroid.
Have the patient lift their arms; if their face becomes plethoric it suggests thoracic inlet obstruction impairing venous return (Pemberton’s sign).
➡️academic.oup.com/jcem/article/9… 5/
Next, a CT scan of the chest & neck revealed a large heterogenous anterior neck mass compressing the trachea.
The mass was biopsied and papillary thyroid cancer was diagnosed. He underwent resection and was cured. His dyspnea and wheezing resolved completely. 6/
Asthma is common but misdiagnosis is surprisingly common too. One study found up to 41% of “asthmatics” did not meet diagnostic criteria.
➡️pubmed.ncbi.nlm.nih.gov/15045041/
It is prudent to confirm the diagnosis w/ PFTs. Failure to respond to Tx should prompt consideration of mimics.
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To summarize what we’ve learned:
* fixed airway obstruction can cause dyspnea & wheezing, mimicking asthma; history & exam can help differentiate
* look at flow volume loops on PFTs & remember the patterns seen w/ fixed obstruction
* confirm asthma dx before escalating therapy 8/
Alternatively, we can boil this down to two proverbs:
* “Not all that wheezes is bronchial asthma”
- Chevalier Jackson (otolaryngologist)
* "Доверя́й, но проверя́й // Doveryáy, no proveryáy"
- translation: Trust but verify (Russian Proverb)
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Did he have a head CT? What did it show?
Did he have stitches? Tetanus shot?
The NYT ran nonstop stories about Biden’s health after the debate but can’t be bothered to report on the health of someone who was literally shot in the head?
To the people in the replies who say it’s impossible because of “HIPPA” 1. I assume you mean HIPAA 2. A normal presidential candidate would allow his doctors to release the info. This is exactly what happened when Reagan survived an assassination attempt. washingtonpost.com/obituaries/202…
My advice to journalists is to lookup tangential gunshot wounds (TGSW).
Ask questions like:
- what imaging has he had?
- what cognitive assessments?
- has he seen a neurosurgeon or neurologist?
- he’s previously had symptoms like slurred speech, abnormal gait - are these worse?
If you intubate you need to read the #PREOXI trial!
-n=1301 people requiring intubation in ED/ ICU were randomized to preoxygenation with oxygen mask vs non-invasive ventilation (NIV)
-NIV HALVED the risk of hypoxemia: 9 vs 18%
-NIV reduced mortality: 0.2% vs 1.1%
#CCR24
🧵 1/
Hypoxemia (SpO2 <85%) occurs in 10-20% of ED & ICU intubations.
1-2% of intubations performed in ED/ICU result in cardiac arrest!
This is an exceptionally dangerous procedure and preoxygenation is essential to keep patients safe.
But what’s the *BEST* way to preoxygenate? 2/
Most people use a non-rebreather oxygen mask, but because of its loose fit it often delivers much less than 100% FiO2.
NIV (“BiPAP”) delivers a higher FiO2 because of its tight fit. It also delivers PEEP & achieves a higher mean airway pressure which is theoretically helpful! 3/
Results from #PROTECTION presented #CCR24 & published @NEJM.
- DB RCT of amino acid infusion vs placebo in n=3511 people undergoing cardiac surgery w/ bypass.
- Reduced incidence of AKI (26.9% vs 31.7% NNT=20) & need for RRT (1.4% vs 1.9% NNT=200)
Potential game changer!
🧵 1/
I work in a busy CVICU & I often see AKI following cardiac surgery.
Despite risk stratification & hemodynamic optimization, AKI remains one of the most common complications after cardiac surgery with bypass.
Even a modest reduction in AKI/CRRT would be great for my patients. 2/
During cardiac surgery w/ bypass, renal blood flow (RBF) is reduced dramatically. This causes injury, especially in susceptible individuals.
But what if we could use physiology to protect the kidneys?
Renal blood vessels dilate after a high protein meal increasing RBF & GFR! 3/
77 yo with respiratory distress, RR 30, SpO2 80% on non-rebreather at 15 lpm
CXR & TTE are unrevealing
pH 7.58 / PaCO2 24 / PaO2 >500 / HCO3 22
MetHb 0% CarboxyHb 0%
The ABG looks like this:
The answer is sulfhemoglobinemia.
Sulfhemoglobinemia is a *permanently* modified hemoglobin associated with exposure to TMP/SMX, dapsone, phenazopyridine, & other amino & nitro compounds.
It has an altered oxy-hemoglobin dissociation curve.
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Sulfhemoglobinemia is easily confused with methemoglobinemia. Both have very dark colored blood & present with cyanosis. Diagnosis typically requires a specialized lab.
Spoiler: you may have heard that SulfHb is green. It isn’t really. You’re thinking of Vulcans’ blood.