Episode 81 – A Balanced View on Recent EM Literature with Joel Yaphe

EM Cases  - A Balanced View on recent EM Literature with Joel Yaphe

Being an optimist, I'm constantly searching for EM literature that will change my practice in a positive way and ultimately improve the care that I deliver. The past year was filled with promising papers, some of which received a lot of attention. I'm not the only one who is biased towards craving a positive paper - so are the researchers, the journal editors and the public. We all want our field to mightily move forward!

Enter Dr. Joel Yaphe. An EM Residency Program Director at University of Toronto and an ED doc who I admire for his balanced, sensible and practical approach to appraising the literature. In this episode Dr. Yaphe, at University of Toronto's Update in EM Conference - Whistler, leads us through a few key articles from the past year including the REVERT trial to convert SVT, medical expulsive therapy for urolithiasis, steroids in anaphylaxis, and analgesics for low back pain, and discusses whether they should (or rather, should not) change our practice. He challenges authors' conclusions and questions whether the findings are relevant to our patients....



Written Summary and blog post written by Anton Helman, May 2016

Cite this podcast as: Helman, A, Yaphe, J. A Balanced View on Recent EM Literature with Joel Yaphe. Emergency Medicine Cases. May, 2016. https://emergencymedicinecases.com/balanced-view-recent-em-literature-joel-yaphe/. Accessed [date].

Modified Valsalva Maneuver to Convert SVT - The REVERT Trial

Does a modified Valsalva maneuver to convert SVT have any advantage over the traditional Valsalva maneuver?

Background: The traditional Valsalva maneuver has been shown to convert stable SVT in only approximately 15% of patients. By adding a step to the traditional Valsalva maneuver that utilizes increased venous return and vagal stimulation, can we increase the conversion rate?

Appelboam A, Reuben A, Mann C, et al. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet. 2015;386(10005):1747-53. Full PDF

The Study: Non-blinded multi-centre, randomized controlled trial in UK of 433 patients

Two simple steps:



* In a semi-recumbent position patients perform a traditional Valsalva maneuver: Forced expiration producing 40mmHg pressure for 15 seconds by blowing into a special device (blowing into a 10cc syringe which is readily available in your ED is probably equivalent).

* Patient lies down in a supine position and a ED staff member raises the patient's legs to a 45° angle for 15 s (causing increased venous return and vagal stimulation).



https://www.youtube.com/watch?v=8DIRiOA_OsA

Results: Return to sinus rhythm at one minute was 43% with the modified Valsalva maneuver vs. 17% with traditional Valsalva maneuver.



* NNT = 3.8 to convert SVT to patient's baseline rhythm.

* Secondary outcomes included less use of adenosine and other anti-arrhythmic treatment.

* Can teach patients how to do this themselves so that they can self-cardiovert without having to come to the ED.



Issues: This study compared the new technique to an erroneous traditional Valsalva technique ie. the traditional technique in this study had the patient in a 45° semi-recumbent position rather than a supine position. We still don't know if this new technique is any better than a properly performed supine Valsalva maneuver.

Dr. Yaphe's Conclusions: It is reasonable to attempt this modified Valsalva technique in stable patients with SVT in the ED,