#CriticalCare non-COVID teaching case:
An elderly man is admitted to the surgical ICU for monitoring after an uncomplicated kidney transplant. You notice this funny pattern on his arterial line tracing. What’s going on here? #FOAMcc#FOAMed 1/
What’s going on here?
2/
This is pulsus alternans: an alternating strong & weak pulse.
Based on the A-line tracing POCUS was performed that reveled a markedly reduced EF. Coronary angiography showed no obstruction and a diagnosis of stress CM was made. The patient recovered with medical therapies.
3/
At first glance, differentiating pulsus alternans from exaggerated pulse pressure variation (PPV) can be tricky
*pulsus alternans occurs every other beat
*PPV occurs with the respiratory cycle
Slowing down the display can differentiate: This is what increased PPV looks like 4/
Pulsus alternans was first described by Traube in 1872.
Despite 150 yrs of research, the mechanism is not precisely known.
There are two theories, related to either beat-to-beat variation in pre-load or in contractility.
The *pre-load theory* is that impaired contractility (causing a weak pulse) leads to an increased end diastolic volume at the next systole. With more filling, the next contraction ejects more blood (causing a strong pulse) due to the Frank-Starling principle. 6/
The alternative *contractility theory* is that residual cytoplasmic Ca2+ after a weak systole causes a stronger cardiac contraction on the next beat.
Whatever the mxn, pulsus alternans is associated with poor systolic function.
7/
🥡Points:
🫀Pulsus alternans on an arterial line tracing can be a useful diagnostic clue for decreased systolic fxn
1⃣📟 See this new ICU OnePager on arterial Lines for more onepagericu.com 8/
📚Historical/literary note:
DH Lawrence beautifully describes Pulsus Alternans in Sons and Lovers:
"…he felt her pulse. There was a strong stroke and a weak one, like a sound and its echo. That was supposed to betoken the end."
9/9
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Damn. Under Trump the White House Medical Unit was a pill-mill. Thousands of ambien & provigil per month.
Worse, for a clinic that doesn’t typically do procedures w/ moderate sedation they sure are they ordering prodigious quantities of morphine, fentanyl, versed, & ketamine…?
Honestly, this reminds me of Norman Ohler’s Blitzed.
The AG report was largely concerned with the enormous cost of prescribing these non-genetic meds.
It’s worth pointing out that dispensing prescription meds without documentation is malpractice. In the case of controlled substances it’s also likely a crime.
The long awaited #COVIDOUT RCT is now in @TheLancet:
- high risk adults randomized to either metformin (MET), ivermectin (IVM), fluvoxamine (FLV) or placebo.
- MET reduced the risk of long COVID (6.3% vs 10.4%; NNT = 24)
- no benefit with IVM or FLV
Pulmonary teaching case: you are called to the bedside of a 60yo man who was admitted for pneumonia a week ago. You were called because “he coughed and now his chest is PULSATING!”
This is what you see at the site of a previously removed chest drain:
EN is a rare complication of an infected pleural effusion where purulent fluid “escapes” the pleura and erodes into the chest wall, causing an extrapleural fluid collection that communicates with the pleural space.
Because Empyema necessitans communicates with the pleural space, fluid can move back & forth with respiration, as seen here:
With inspiration, negative intra-thoracic pressure pulls the fluid into the chest. With expiration, positive intra-thoracic pressure pushes fluid out. 3/ twitter.com/i/web/status/1…