André Martin Mansoor Profile picture
Mar 16, 2022 8 tweets 4 min read Read on X
1/8
A young woman presents with progressive dyspnea. You walk into the room and this is what you see.

What finding is present?
2/8
Central cyanosis indicates the presence of hypoxemia. SPO2 by pulse oximetry is 80%. ABG on room air shows PaO2 of 40 mm Hg and PaCO2 of 30 mm Hg.

We reference our framework for hypoxemia to begin the process of narrowing our differential diagnosis.
3/8
The first thing we want to know is the A-a gradient.

A (from the alveolar gas equation) = 112 mm Hg
a (from the ABG) = 40 mm Hg

A-a = 112 - 40 = 72 mm Hg.

Elevated.
4/8
Next we revisit the physical examination for more clues. There is profound peripheral cyanosis. But what else do you notice?

If you don't specifically look for this finding you might never notice it. "The eyes can't see what the mind doesn't know."
5/8
Clubbing indicates that we are likely dealing with an anatomic shunt.
6/8
The patient's precordial movement shown here is suggestive of an intracardiac shunt. @PeteSullivanPDx teaches that the chest can move in this way when blood travels from a higher pressure chamber to a lower pressure chamber. In this case, from the right to the left.
7/8
Our diagnosis is confirmed with an echo with agitated saline contrast. Bubbles appear in the LV within 3 beats.

Bubbles are normally filtered by the lungs. They only appear in the L side of the heart if there is an intracardiac (few beats) or intrapulmonary shunt (>5 beats).
8/8
We diagnosed an intracardiac shunt with our eyes, a Q-tip, and a few specific hypothesis-driven tests.

Physical exam plays a critical role in diagnosis.

For more cases: physicaldiagnosispdx.com/case-presentat…

Source of hypoxemia framework: amazon.com/Frameworks-Int…

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More from @AndreMansoor

Jun 22
1/11
Una joven ingresa con epiglotitis aguda (bacteriemia por H. influenzae). Durante su hospitalización, la paciente desarrolla pancreatitis aguda y hematuria con IRA.

Un conjunto de problemas bastante confuso ¿Cómo podemos encajar todas las piezas de este rompecabezas? Image
2/11
En un paciente con hematuria, la primera pregunta que siempre hago es: ¿cuál es el origen de la sangre? ¿glomerular o no glomerular? Image
3/11
¿Cómo saber si la hemorragia es de origen glomerular o no?

Tenemos que evaluar el sedimento urinario, pero los ojos no pueden ver lo que la mente no sabe. Entonces, ¿qué estamos buscando? Image
Image
Read 11 tweets
Jun 17
1/11
A young woman is admitted with acute epiglottitis (w H flu bacteremia). While hospitalized she develops acute pancreatitis and hematuria with AKI.

A confusing constellation of problems. How can we glue this story together? Image
2/11
In a patient with hematuria, the first question I always ask is as follows: what is the source of that blood? Is it glomerular or non-glomerular? Image
3/11
How can we tell if the bleeding is glomerular or not? We have to evaluate the urine sediment. But the eyes can't see what the mind doesn't know. So what are we looking for? Image
Image
Read 11 tweets
Jun 4
1/10
A 70-year-old man presents with dyspnea. What do you notice when you first meet him?

This finding should generate a hypothesis, which we will circle back to eventually. Image
2/10
Before we do, let’s talk about dyspnea. The two main systems responsible for dyspnea are the heart and lungs. Image
3/10
The jugular venous pulse can serve as a pivot point. It can take you toward or away from the heart. With this in mind, let’s evaluate the patient’s neck. Here, he is in the upright position. (Sometimes the jugular venous pulse is better seen on the left.)
Read 10 tweets
May 14
1/16
A 30 year old man presents with tea-colored urine. Image
2/16
Our instinct is to consult the framework for hematuria: Image
3/16
Then we realize that while the color of the urine could absolutely be consistent with hematuria, there are mimics of hematuria that should be considered as well. Image
Read 15 tweets
Apr 21
1/13
A man is admitted with acute abdominal pain, nausea, vomiting, and diarrhea. HR 130, BP 90/52.

You walk into the room to meet the patient. What do you notice? This should generate at least one hypothesis. Image
2/13
You ask him for an old photo for comparison. His wife pulls out her phone and produces this picture (B) taken about 10 years prior.

Pt reports darkening of skin over an 8 year period (for which he saw several clinicians). What conditions are you considering? Image
3/13
Let’s first consider the hypotension. Image
Read 13 tweets
Apr 9
1/
A middle-aged man presents with acute sudden-onset dyspnea and hypotension. He is sitting upright.

What do you notice? Let’s see if we can figure out the cause of hypotension.
2/
First.

What are the 4 basic mechanisms of hypotension?

Hypotension can be hypovolemic, cardiogenic, distributive, or obstructive. Image
3/
Hypovolemic hypotension occurs because of a decrease in preload. The pump is ready, the blood vessels are ready, but the "ammunition" is not there. JVP low, extremities cool.

2 arrows down for CVP/JVP since that is the primary issue. Image
Image
Read 20 tweets

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