Another Blood pressure & Diving
Dose blood pressure increase dewing deep diving?
I did a 50m dive for 30min today, would my blood pressure have increased while i was down there?
Have ark a few doctors that dive but no one knows.
Dear Peter
Blood pressure does go up with immersion and cold (maybe the latter not so relevant in your part of the world). In some people there is a massive rise in blood pressure due to severe vasoconstriction and this is part of the cause of diving induced pulmonary oedema (read Wilmshurst P about it in the literature). I agree with the previous posts that it is not aproblem for an otherwise fit person, but there are a few people with this pathological rise in BP which can occur at 10 metres. Those with high bp should not dive, partly because they are at increased risk of pulmonary oedema.
Mark Turner
Hello,
See Peacher et al. Journal of Applied Physiology 2010;109:68-78 (the July 2010 edition).
This study was unique in having immersed exercising divers who were fully instrumented with arterial, central venous, and pulmonary artery catheters. It is a complex paper and contains a lot of useful information. But of relevance to this thread, there is a significant increase in MAP during immersion / diving which is further increased during exercise but not significantly affected by depth. Thus, immersed resting at surface mean MAP was 98 which increased to 117 during exercise and did not change much between surface and 37m either during normoxia or hyperoxia.
What does it all mean? I would agree with Mike: probably not much in a fit and well person who can cope with normal levels of activity at the surface.
Regards,
Simon Mitchell
Well put Glen!
To be even less technical, essentially the answer is 'not much if at all'. As Glen suggests, there may be a very small increase in BP and a reduction in resting heart rate, but likely that the latter is overwhelmed by exercise.
Certainly there is no dangerous increase in BP for any reasonably fit person.
Now, to be more technical: in an ABSOLUTE sense the pressures increase enormously - but this is meaningless to our health or internal well-being. Consider, on the beach your blood pressure might be 120/70 (mmHg). At 20 metres the gauge pressure is 2 bar , so the real blood pressure could be expressed as 1640/1590...
Mike
Yes and no and depends.
When you first go into the water and are bobbing around on the surfaceyou have dynamic compression from the water, This gives you a venous return increase to the heart which manages it by increasing heart rate.
As you equilibriate out it settles and then depends on the activity that you are performing.
With deep diving you have a multitude of factors combining (increased work of breathing, finning around etc) so it is a bit hard to give a definitive answer but yes it would increase during a deep doive, slightly more than a shallow dive but your body should be able to adjust to keep it within a normal range.
Regards Glen