Grandmother on a vent for an autoimmune disease called myasthenia gravis, bp dropping 90/30 whats going on?

shes recieving treatment to remove the antigens that are attacking her resp. system this bp is very low for her shes 79 yr. old anyone out there can give me some idea whats going on

she is in NICU but was doing much better until the plasma exchange i know they know what their doing im just so scared, she just looks like shes in so much pain this myasthenia does NOT mess around!

Myasthenia gravis is an autoimmune disease that affects the neuromuscular junction. Basically her antibodies are blocking the receptors for a neurotransmitter called acetylcholine that is vital for controlling muscle movement. In cases of myasthenia crisis (like during an infection or reaction to certain drugs), such patients can decompensate very quickly and require intubation since the respiratory muscles get affected and they are too weak to breathe on their own. Fortunately, with proper supportive treatment (intubation, correction of the underlying trigger which is usually an infection and either plasma exchange or IVIg to filter out the anitbodies), prognosis is usually good.

Also if she's in a neuro intensive care unit, they know what they are doing.

If she is on vent and develops bronchospasm, it needs to increase inspiratory pressure in order to ventilate thru the high resistance respiratory tract. This increases intrathoracic pressure, which in turn lowers BP.
She must be well monitored and under expert care. Don't worry.

ask her docter but dont get in the docters way

Sweetheart, without looking at her chart, I can't say for certain why this is happening. Is she getting enough fluid replacement? Perhaps she needs one or two boluses of 250 cc? Perhaps she needs to be placed on pressors, but I'm sure that the intensivist is monitoring these things closely.