Valsalva, Venous return, and Diving

[goodknight411]

My nursing instructor, a PhD in nursing, told us that patients with difficulty breathing should avoid doing the valsalva manuver because it decreases venous return by placing pressure on the chest cavity and heart.

I was wondering if this could have any affect during a dive if the diver was using valsalva alot. I'm figuring it's not a problem unless you have somekind of medical condition, but then I doubt you'd need to be diving anyway.

Just a question I got in my head and couldn't work out on my own. Any comments or ideas?

 

[Wildcard]

No more so than say, coughing or sneezing. Also you need to look at the cause of the SOB. CHF, Asthma, COPD, ect. They shouldn't be making blanket statements without addressing the issues.

 

[jbd]

My nursing instructor, a PhD in nursing, told us that patients with difficulty breathing should avoid doing the valsalva manuver because it decreases venous return by placing pressure on the chest cavity and heart.

I was wondering if this could have any affect during a dive if the diver was using valsalva alot. I'm figuring it's not a problem unless you have somekind of medical condition, but then I doubt you'd need to be diving anyway.

Just a question I got in my head and couldn't work out on my own. Any comments or ideas?

Most likely what your instructor is referring to is a prolonged effort when performing a valsalva i.e. pushing during childbirth, straining to defecate and possibly prolonged coughing.

In diving it takes a very short time to equalize the ears and the effort is considerably less than the above mentioned activities.

As I recall, patients with compromised cardio/pulmonary systems were placed on diets or medicated to prevent straining to defecate for the reasons mentioned by your instructor.

 

[goodknight411]

Thanks. Sometimes she hits things in a rush and doesn't get to explain it completely. I guess the blanket statement was where my confusion came in.

 

[Mako Mark]

someone with compromised respirtary system probably would be precluded from diving anyway..

 

[GoBlue!]

Valsalva & difficulty breathing. There is no general statement you can make about the two, and it's inappropriate for an instructor to make such a statement without explaining further, in my opinion.

(In fact, I've had a few patients that I instructed to perform a Valsalva maneuver, because of a specific cardiac arrhythmia, to "treat" their shortness of breath.)

Jim

 

[Wildcard]

I asume you mean SVT?

 

[GoBlue!]

I asume you mean SVT?

Yes. AVNRT, specifically, in the cases to which I referred.

Jim