Tyler Larsen Profile picture
Hospitalist @LosAngelesVA | Educator @dgsomucla | Passionate about #MedEd, physical diagnosis, and clinical reasoning. Tweets are my own.
Reza Hosseini ⚕️ Profile picture 1 added to My Authors
17 Apr
1/ "Who feels comfortable evaluating a tracheostomy?"

Today on the wards we talked trachs. Though we see patients with trachs regularly I find it is a topic that few learners are comfortable with.

The following 🧵 is my "Hospitalists' Guide to Tracheostomies"

Where are trachs placed anatomically?

Trachs are placed between the cricoid cartilage and the sternal notch around the 2nd to 4th tracheal ring. These can be placed surgically or percutaneously at the bedside.
Anatomy of a Trach

When evaluating a trach, I find it helpful to consider the following:
🔹 Diameter - Is there an inner cannula or single lumen?
🔹 Length - Is it regular size or an Extended Length Trach (XLT)?
🔹 Cuffed or cuffless?
🔹 Fenestrations present?
Read 15 tweets
18 Feb
Does atelectasis cause post-operative fever?

I occasionally hear atelectasis listed in the differential diagnosis for early post-op fever (EPF) but this idea has never made much physiologic sense to me.

Let's explore this question in the following #tweetorial.
Like many US medical students, I first learned this central dogma of post-op fever on my surgical clerkship through the perpetuation of a rather cumbersome and inelegant mnemonic involving the letter W.
Despite its ubiquity, however, there is little published evidence to support this idea. One of the largest systematic reviews on the topic found that in 7 of 8 studies there was no significant association between atelectasis and early post-op fever.

PMID: 21527508
Read 19 tweets
29 Jul 19
1/ Why are EKG waves named starting with the letter P? What happened to letters A through O?

I’m guessing you’ve probably never wondered this, but if you’re curious, here’s a brief historical #medthread / #tweetorial on how the EKG waves got the names they did.
2/ The first electrical tracings of the heart were obtained in 1887 by A.D. Waller, a British physiologist and physician, who used a Lippmann capillary electrometer to capture the tracings.

3/ As a physiologist, Waller labelled the two waves on his initial tracing V1 & V2 based on their site of anatomic origin- the ventricle. He would continue, often rather adamantly, to refer to the electrical waves as A, V1, & V2 throughout his career.

Read 11 tweets
17 May 19
1/ Ok #medtwitter, here goes my first attempt at a #tweetorial, inspired by a recent question on wards from a learner I didn't know the full answer to:

“How good is a tuberculosis (TB) 'rule-out'?”

To try to answer this question we'll first start with a case.
2/ A 62yo female w/ recent renal transplant and remote hx of pulm TB s/p 1y DOT presents with fever. 4 wks PTA was hospitalized for 2 wks of cough, unintentional 20lbs weight loss & large LUL cavitary lesion on CT.
3/ Extensive work-up including bronchoscopy only reveals +human metapneumovirus. 4 AFB sputum smears and 3 MTB PCRs (including BAL) are negative. AFB cultures are NGTD. Patient is d/c on empiric posaconazole. 1 wk later she returns to ED with temp 102F. Cough is now resolved.
Read 16 tweets