Investigators at the Royal North Shore Hospital in Sydney (it’s good there) did a literature review to determine the best ‘gold standard’ way of performing a Valsalva manoeuvre for SVT, and assessed success rates before and after its introduction into the ED.
The technique required the patient to lie supine on the bed in a Trendelenberg position, and forcefully expire into a section of suction tubing and pressure gauge for at least 15 seconds and at a pressure of at least 40 mm Hg. The theory behind increased success in a supine position lies in augmenting the patients’ vagal tone and attenuating the sympathetic tone in addition to increased venous return during phase IV of Valsalva. The ‘standardised’ technique improved the rate of successful termination of SVT from 5.3% to 31.7%
Impact of a modified Valsalva manoeuvre in the termination of paroxysmal supraventricular tachycardia
Emerg Med J. 2010 Apr;27(4):287-91