II. Technique
- Standard Valsalva Maneuver
- Forceful expiration against a closed mouth and nose
- Postural modification significantly increases efficacy in PSVT cardioversion
- Valsalva is initially performed with head of bed at 30-45 degrees
- In study, Patient blew into a manometer attempting to sustain 40 mmHg for 15 seconds
- Patient repositioned immediately after Valsalva Maneuver
- Patient is layed supine and legs are passively raised
- References
- Valsalva is initially performed with head of bed at 30-45 degrees
- Reverse Valsalva Maneuver
- Patient is seated
- Exhales fully in regular fashion
- Pinches their nose, closes their mouth and inhales for 10 seconds
- Patient then resumes normal breathing after 10 seconds (opening mouth and removing hand from nose)
III. Physiology
- Increases intrathoracic pressure
- Briefly (<3-5 seconds) results in mildly increased Cardiac Output
- Decreases venous return
- After first 3-5 seconds, results in fall in Cardiac Output, and typically drop in Blood Pressure
IV. Indications
- Pressure equalization of nose and sinuses
- Examples: Drop in altitude in plane flight or increased external pressure in diving
- Other maneuvers are preferred (Yawning, Swallowing)
- Evaluate Tympanic Membrane mobility
-
Supraventricular Tachycardia
- Functions as a Vagal Maneuver
- See Techniques above (esp. Postural modification, Reverse Valsalva
- When Valsalva Maneuvers are effective in breaking SVT, they typically work within 15 seconds of maneuver
- Evaluate cardiac murmur
- Increases murmur or abnormal heart sounds
- Decreases murmur
V. References
- Bates (1991) Physical Exam, 5th ed, Lippencott, p. 302
- Warrington (2024) Crit Dec Emerg Med 38(11): 17