Low BP vs drysuit neck seal?

[Soggy_Diver]

Hi,

One of my dive buddies has a blood pressure at the low end of normal, around 90/60. Twice lately, when she was diving a drysuit with a latex neck seal, she has felt light headed and ended the dive early. She does not find her neck seal uncomfortably tight. I was with her when this happened recently, and when I finger checked it, it felt snug but not tight. She had not had this issue when diving with a wetsuit.

My question is, could her low BP be causing carotid sinus reflex, even with a dry suit seal that is not tight?

In the meantime, she is planning to trim the seal further, and hope it does not leak.

Thanks in advance for any thoughts.

 

[Scott Lemmon]

emedicine.medscape.com has a good article, Carotid Sinus Hypersensitivity. Pressure stimulation of the carotid baroreceptors (to either side of the trachea in the neck) can cause a drop both in blood pressure and heart rate. With an already low blood pressure, your buddy is probably at an increased risk for these problems. Unless she can arrange the neck seal below the anatomic site of the carotid baroreceptors (https://scontent-sjc3-1.xx.fbcdn.ne...=86fa2faf28fc604d77f9bb20e76cd011&oe=60E7BBC8) it may be impossible to avoid the effects of compressing these vascular pressure sensors. Not being a physician, i would caution your buddy against continuing to use a dry suit with a neck seal unless she is able to avoid pressure on the carotid baroreceptors. the good news that i have read is that these receptors decline in sensitivity as you age, so her experience may improve.

 

[grantctobin]

@Duke Dive Medicine

Additionally, I'd consider reaching out to Derek Covington at University of Florida and see if the recent testing he's done has come to a close. He was measuring seal restrictiveness, blood pressure, and ocular tension? or similar towards the end of last year on divers around cave country and had done some backstudies on such things.

 

[Zef]

I find silicone neck seals stretchier and more comfortable than latex ones...perhaps installing a si-tech neck ring system and using one of their silicone seals may be worth a try.

-Z

 

[Duke Dive Medicine]

Hi,

One of my dive buddies has a blood pressure at the low end of normal, around 90/60. Twice lately, when she was diving a drysuit with a latex neck seal, she has felt light headed and ended the dive early. She does not find her neck seal uncomfortably tight. I was with her when this happened recently, and when I finger checked it, it felt snug but not tight. She had not had this issue when diving with a wetsuit.

My question is, could her low BP be causing carotid sinus reflex, even with a dry suit seal that is not tight?

In the meantime, she is planning to trim the seal further, and hope it does not leak.

Thanks in advance for any thoughts.

emedicine.medscape.com has a good article, Carotid Sinus Hypersensitivity. Pressure stimulation of the carotid baroreceptors (to either side of the trachea in the neck) can cause a drop both in blood pressure and heart rate. With an already low blood pressure, your buddy is probably at an increased risk for these problems. Unless she can arrange the neck seal below the anatomic site of the carotid baroreceptors (https://scontent-sjc3-1.xx.fbcdn.ne...=86fa2faf28fc604d77f9bb20e76cd011&oe=60E7BBC8) it may be impossible to avoid the effects of compressing these vascular pressure sensors. Not being a physician, i would caution your buddy against continuing to use a dry suit with a neck seal unless she is able to avoid pressure on the carotid baroreceptors. the good news that i have read is that these receptors decline in sensitivity as you age, so her experience may improve.

Carotid sinus hypersensitivity can be tested for and diagnosed. I couldn't get the link in @Scott Lemmon 's post to work; here's a link to a StatPearls article, with a very strong "don't try this at home" caveat. Testing should be conducted by a competent practitioner who's prepared to intervene in case of a precipitous drop in blood pressure and/or heart rate. I'm assuming if you're in Ontario you dive drysuits regularly and know a neck seal that's too tight when you see one

Best regards,
DDM

 

[Soggy_Diver]

Thanks everyone, for this information and these links. I am passing this on to her.