Marking the surface anatomy for procedures can significantly increase your chances for success, such as for lumbar punctures and central lines. I can never seem to find surgical skin markers. 

Trick of the Trade:

Use a Sharpie marker

Did you know that Sharpies are inherently sterile, likely because they contain N-propanol? There was an in vitro study where they used a Sharpie vs Secureline (surgical skin marker) to draw across blood agar plates inoculated with various bacteria. At 4 hours, there was no bacterial growth on the Sharpie pen tip, while all of the Securelines had bacterial growth.

Read more: http://www.jstor.org/stable/10.1086/650377

Microsoft Word - figure 1 redone.doc


Thanks to Dr. Jeff Wiswell (PGY-2 EM resident and upcoming chief resident at Mayo) for this tip! He recently recounted his use of a sharpie:

I recently had a patient arrive with massive angioedema who was metastable but needed a definitive airway.  As we were administering glycopyrrolate and nebulized/topicalized lidocaine, along with getting our fiberoptics setup, I was thinking about my backup plans.

We had a glidescope, LMA, and crich kit at the bedside, but the thing that gave me the most confidence was the Sharpie marker I realized was in my scrub top.

After reading a study about their superior sterility compared to disposable surgical pens, I’ve been using them to mark landmarks for LPs and the IJ trajectory for needle placement on some central lines.

This evening, however, I directed the nurses to shave the lower half of this patient’s beard and marked the cricothyroid membrane in a controlled setting before my fiberoptic attempt, knowing that I could ultimately locate it accurately and quickly if I reached the end of the algorithm.

Although the nasal fiberoptic attempt went beautifully, I’m not sure what the ICU residents upstairs noticed first:

  1. The massive tongue protruding from the patient’s mouth,
  2. The nasal ETT, or
  3. The big, blue “+” over the patient’s neck . . .


Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at https://t.co/50EapJORCa Bio: https://t.co/7v7cgJqNEn
Michelle Lin, MD