Valsalva Maneuver and Vasovagal response

HonestRN · Jul 28, 2009

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 · Jul 29, 2009

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 · Jul 29, 2009

Thanks very much.

tlc2u · Jul 29, 2009

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 · Jul 29, 2009

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.