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Tricks of the Trade: Valsalva maneuver by using a 10 cc syringe


Last week, Dr. David Johnson shared his trick to elicit a Valsalva maneuver out of his patient. Here’s another trick that I saw one of our EM residents use in an attempt to break a SVT rhythm.



Trick of the Trade

Instruct the patient to blow into a 10 cc syringe in an effort to “blow out” the syringe plunger.1

I was amazed to find a journal article in Emergency Medicine Australia, which¬†documented that an appropriate Valsalva force is generated when a patient is able to move the plunger of a 10 cc syringe by blowing into the syringe! Apparently larger syringes don’t generate enough force (< 40 mmHg) and smaller syringes require too much force (> 40 mmHg).

Smith G, Boyle M. The 10 mL syringe is useful in generating the recommended standard of 40 mmHg intrathoracic pressure for the Valsalva manoeuvre. Emerg Med Australas. 2009;21(6):449-454. [PubMed]
Michelle Lin, MD
ALiEM Editor-in-Chief
Academy Endowed Chair of EM Education
Professor of Clinical Emergency Medicine
University of California, San Francisco
Michelle Lin, MD
Michelle Lin, MD

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