Procedure Videos Online

I wanted to highlight the NEJM’s new (well, 6 months old) internet feature, Videos In Clinical Medicine. You ought to be able to access these videos after logging into the Sinai library (with MSSM-ID and life number) and then heading over the NEJM’s recent videos page.

Many of the videos feature the work of Gary Setnik, MD, an early figure in EM. The most recent one (from Oct 26th, Vol 355, No. 17) is on basic laceration repair — so maybe it’s something you can show to your beleaguered 4th year med student while you’re busy with other things. Other videos may be more relevant to us, including thoracentesis, LP, A-line placement, and knee arthrocentesis. The videos can also be downloaded in formats for Palm OS, Windows, and iPod.

Clinicalcases.org, a very useful collection of links, videos, simulators and more, also has a page full of procedure video links, as well as some physical exam videos that may be worth brushing up on.  

If you’re aware of any other good online resources like this, let me know or share ’em with Ted, who’s compiled a list of his own.

Dr. Hoxhaj’s Top Papers / Wound Care

Dr. Hoxhaj gave a great presentation at the beginning of my intern year, on some of the top papers in emergency medicine published this . His criteria for excellence? They were either landmark works that changed EM practice, or well-conducted research with surprising conclusions that challenged dogma and made us think. Or, as he said, he's just messing with us.

Over the next few weeks, I'll post some of these papers here, as blog entries. Each post will have a link to the papers mentioned, plus some of his commentary gleaned from his slides. Feel free to add your own comments (especially if you're Dr. Hoxhaj).

The first papers I wanted to mention involve wound care — specifically, some novel, and maybe cavalier, ways of treating lacerations.

A Tetramer Peptide for Alkali Corneal Burns?

Hot on the heels after Chris’s masterful lecture on BRUNS, and a tox fellow’s presentation of caustic ingestions, I was asked to present a paper on a novel therapy for the alkali-injured cornea. The paper chosen discussion was called L-Arginine-Threonine-Arginine RTR tetramer peptide inhibits ulceration in the alkali-injured rabbit cornea, and it’s a good deal more basic than most featured on this site. But it prompted a nice discussion on ophtho burns, so I’m including it here.

It’s by Pfister and Sommers, Cornea Vol 25 No 10 pp1187-1192 (December 2006). The PDF is available through Ovid for Sinai library users. This group has been working on peptides for corneal burns for ten years. Some background:

The standard therapy for chemical injury to the eye, as described by Tintinalli, is immediate copious irrigation, with at least 1-2 L of NS.  We use litmus or pH paper to assess effectiveness, keep irrigating until pH of tears in the lower cul-de-sac is pH 7.5 – 8. Acid burns tend to coagulate proteins and thus limit depth. Alkali burns are more concerning. If, after irrigating, a corneal epithelial defect is seen, we give erythromycin ointment and a cycloplegic. If there’s no defect, erythromycin ointment alone is given.

For alkali ocular burns, many toxicologists also recommend steroids, citrate, and ascorbate… The only systematic review is retrospective, in Ophthalmology 2000 Oct;107(10):1829-35 despite the fact that ascorbate (Vitamin C) has been used for decades and steroids for this use have been studied even longer. Emcrit.org has some useful info on chemical burns in general, and emedicine covers ocular burns well .

The authors begin by noting corneal ulceration is due to an inflammatory response of neutrophil invasion. This invasion is mediated by methylated, acetylated PGP (proline-gylcine-proline), which is a product of hydrolyzed corneal proteins from cells and ECM.

So, the authors wanted to inhibit the effect of Ac-PGP on neutrophils, so they created RTR (arginine-threonine-arginine). Why, exactly?

“protein molecules recognize one another in a genetically defined manner… This method is from the development of complementary peptides specified by ligand antisense RNA”.

In previous work, the authors showed that an RTR tetramer is a potent inhibitor of PGP chemoattraction. They showed that both the L- and D- form of RTR inhibited the incidence and serverity of corneal ulceration, when given topically on an alternate-hour basis.