Valsalva maneuver

[Just_Kidney, ADN, BSN, RN]

Okay, so maybe I'm just dense, but I'm really confused by this. The Valsalva maneuver promotes a vasovagal response (parasympathetic response): lowering B/P, pulse and increasing vasodilation, right? But my NCLEX review book says to have patients perform the Valsalva maneuver (unless contraindicated) when doing central line tubing changes to increase pressure in the central veins thus helping to prevent an air embolism? But how would the Valsalva maneuver increase central venous pressure? Also, I know it's contraindicated in patients with increased intercranial pressure, recent eye surgery, etc because it increases ICP, which also does not make sense to me physiologically.

Can someone please explain this, I'm just not getting it!

[chare]

I have two questions for you.

1. When you ask a patient to perform a valsalva maneuver what exactlty do you ask them to do?

2. What are the pressure differences during the ventilatory cycle?

Think about these and you should be able to determine this on your own.

[kool-aide, RN]

When one coughs, bears down, or forcefully exhales pressures are increased in the head, eyes, thoracic, and abdominal cavities. This increased pressure causes increased venous pressure which is needed when, for instance, removing a IJ line. If the pt is inhaling at the time it's pulled, an air embolus can result.

[Bedside_Life RN]

In my experience, the valsalva maneuver can be used, with an understanding that the force exerted by the patient should be reflective of what the situation calls for. For example, if I am pulling a PICC or IJ I may ask the patient to take a deep breath and hold it; then slowly exhale after the catheter has been removed and pressure has been applied. Quite often your heart rate will increase upon inspiration and slow upon expiration. This would be beneficial instruction; taking into consideration the situation. On the other hand, the valsalva maneuver can be used to a greater extent or with greater force exerted by the patient in the event that the heart rate needs to be decreased in an emergent situation. For example, your next door neighbor comes to you complaining of palpitations or what may be SVT and you advise them to sit on the toilet or in a chair and exert force as if they were having a bowel movement. The difference is that this type of valsalva maneuver produces a vagal response, instead of simply creating "back pressure" as I mentioned with the PICC or IJ. For the neighbor with SVT, the force has to be sustained long enough to cause a decrease in heart rate, but not to the extent that syncope results. Sometimes, you will find that a patients history includes vagal induced cardiac arrest. This is the prime example of a valsalva maneuver, creating a vagal response, resulting in bradycardia (due to sustained exertion) until the point of syncope and non-life sustaining EOP. So to truly answer your question, a nurse has to use their judgement to instruct and inform the patient how to appropriately use the valsalva maneuver according to their condition and situation. Hope this helps you.