Valsalva Maneuver and Vasovagal response

Nurses General Nursing

Published

Just wondering if I have this concept right.

When the vagus nerve is stimulated HR lowers, BP rises then lowers, gastric secretions increase. I'm not sure what else it does but that's what I know so far. And these symptoms are called a Vasovagal response?

The Valsalva Maneuver causes vagus nerve stimulation and a vasovagal response is exhibited?

In one NCLEX question I came across it stated that a person should avoid Valsalva Maneuver to avoid risk of hemmorhage due to the increase of BP. So I just wanted to get my facts straight.

Thanks in advance.

HonestRN

454 Posts

Specializes in cardiac, ortho, med surg, oncology.

The valsalva maneuver is used to stimulate a vasovagal response i.e. decrease HR and BP. Hemorrhage is not likely because if there is a BP increase it is minimal and transitory. The exception would perhaps be in cases of retinal hemorrhage due to strong and sustained valsalva maneuvers.

tlc2u

226 Posts

op wrote:

in one nclex question i came across it stated that a person should avoid valsalva maneuver to avoid risk of hemmorhage due to the increase of bp. so i just wanted to get my facts straight.

a valsalva maneuver is when a person holds their breath and bears down like when having a bowel movement while constipated or when lifting something very heavy. a little extreme; but vivid mental picture; would be of a weight lifter lifting massive barbells.

the nclex question you referred to, was there a disease process mentioned that may cause concern for possible hemmorhage or bleeding (ex. aaa, or post prostate surgery). one of my med-surge textbooks cautions against valsalva maneuver post prostate surgery.

op wrote:

the valsalva maneuver causes vagus nerve stimulation and a vasovagal response is exhibited?

vasovagal response is not referenced in my textbooks but just breaking down the word it should refer to the response of blood vessels-(vaso) to vagus nerve stimulation-(vagal).

op wrote:

when the vagus nerve is stimulated hr lowers, bp rises then lowers, gastric secretions increase. i'm not sure what else it does but that's what i know so far. and these symptoms are called a vasovagal response?

to understand what the vagus nerve does it helped me to understand the parasympathetic and sympathetic nervous systems.

parasympathetic"rest and digest"activated by acetylcholine-cholinergic

sympathetic "fight or flight" activated by adrenalin-adrenergic

associating these terms helps me understand and remember this.

parasympathetic ns-acetylcholine-cholinergic response-muscarinic response

when the vagus nerve is stimulated neurotransmitters are released that activate the parasympatheic nervous system. acetylcholine is a neurotransmitter of parasympathetic neurons. nerves that release acetylcholine are said to be cholinergic and acetylcholine stimulates muscarinic receptors. so if i know what happens in the parasympathetic or cholinergic response then i know the reverse happens when i administer an anticholinergic medication.

sympathetic "fight or flight" activated by adrenalin-adrenergic

stimulation of the adrenal medulla releases adrenaline (epinephrine) which increases sympathetic nervous system activity.

the following table reviews the actions of these neurotransmitters as a function of their receptors. chart is from: http://en.wikipedia.org/wiki/autonomic_nervous_system

in school i recall reading that as the valsalva maneuver slows the heart rate then it could be used as a temporary measure to slow svt's. also if a patient had a bradycardia concern then a valsalva maneuver would be contraindicated, therefore you would not want the brady patient to strain with constipation and would expect orders for stool softeners.

hope this helps,

tlc2u

IcanHealYou

174 Posts

Specializes in Medicine.

Thanks very much.

tlc2u

226 Posts

You're welcome.

If you come across that NCLEX practice question again I would love to know what disease process or patient problem it was refering too.

Thanks,

tlc2u

EricJRN, MSN, RN

1 Article; 6,683 Posts

A Valsalva maneuver can cause a marked increase in intracranial pressure, so I wonder if they were referring to a risk of cerebral hemorrhage.

A specific type of vagal maneuver, carotid sinus massage, is contraindicated in patients with occulsive vascular disease of the carotids - and some sources say that it's contraindicated for all elderly patients. The big risk there, however, would be a thromboembolic stroke, not a hemorrhagic one.

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