Reverse squeeze

[Lee Taylor]

On rare occasion I have experience a reverse squeeze between 15ft and the surface. It is extremely painful (probably due to the stretching of the eardrum). It seems the pain is due to the eardrum being restricted from bulging outwards (as it naturally does due to the pressure relief during an ascent). I am guessing that the inner ear tube (eustachian tube) is collaping due to an over-demand of air flow caused by "too fast" of an ascent. This has only happened to me twice and it is a horrible experience. Both times I had lost control of my dive for a minute. The factor involved that I suspect is the root cause of the problem is too quick of an assent between 15ft and the surface. In both cases I was a little positive in regards to my BC, I released my grasp on the dive line for a moment, and a small current hit me just right and I was quickly moved from 15ft to 3ft of the surface. Helpful speculation on this would be insightful. Thanks in advance.

 

[String]

Reverse block is identical in cause to a normal block except it happens when the pressure inside is higher than outside (ie on an ascent). It can still cause identical ruptures and damage. Big issue with a reverse block is you have to come up sometime. If its a normal block on descent you just abort - with a reverse eventually due to gas you HAVE to come up and potentially damage your ear.

As a side note you mention "released my grasp on the dive line" - are you really relying on holding onto a rope or line to ascend or do a stop? A rope should be a guide and nothing more, buoyancy should be controlled and managed without having to hold onto anything.

 

[don Francisco]

Reverse block of the ears isn't all that common, since positive pressure would tend to keep the eustachian tubes open. However there are limits to how fast ears equalize, so your problem as a result of an uncontroled rapid ascent isn't surprising.

Don't think about trying to speed up the ear clearing on ascent, focus more on managing the ascent properly, especially the last 15 feet where the pressure change is the fastest. If you can't stay neutral or slightly negative at 10 foot depth at the end of your dive, when your tank is at 500psi, add a pound or two of ballast.

IMO the ability to manage an ascent and safety stop without an anchor line or other aid is one of the more important skills, since you never know when you might have to. I suggest you work on it at the end of your next few dives.

 

[Deefstes]

I've always wondered about reverse block. It was mentioned during our OW training but no-one ever explained what you should do if you do encounter it. Of all the things relating to diving, this is probably the one that terrifies me most. I can just imagine being 5m below the surface and not being able to go further because your ears won't let you, all the time watching as your cyllinder pressure runs out.

 

[TSandM]

As has been stated, reverse block is less common than an initial failure to equalize. Often, reverse blocks are associated with some degree of preexisting congestion, making it difficult to equalize on descent. Some barotrauma occurs there, and the edema (swelling) increases during the dive, until on ascent, the Eustachian tube can no longer open. If it is swollen but not shut, a sufficiently slow ascent may permit the air to escape, but a rapid one will exceed the ability to vent the middle ear. It is painful for a good reason; you can blow an eardrum doing this.

I would recommend three things: One, don't dive with any recognizable congestion. Two, watch THIS video about the diver's ear (warning: it's about 45 minutes long), because there is a lot of good information about equalizing in it. And three, as has been said by the other posters, work on your buoyancy control in the shallows, until being knocked off the upline doesn't result in a rapid ascent.

 

[Deefstes]

Thanks TSandM. That's probably the best answer I've received so far but I'll have to be honest that the idea of reverse block still terrifies me.

One, don't dive with any recognizable congestion.

That sounds like a perfectly sensible suggestion. As they say, prevention is better than cure.

Two, watch THIS video about the diver's ear (warning: it's about 45 minutes long), because there is a lot of good information about equalizing in it.

I've been pointed to this video a number of times. It seems to be the de facto internet resource for answering questions on equalising. I have to be honest though, and it seems as if I'm the only one, but after sitting through 45mins of the video (not just now, some time ago), I was a bit disappointed. The guy had a few tips on equalising and brought one person after the other onto the stage to look at their ears but had pretty much the same advice for all of them.

He also mentioned reverse block but didn't give any particular advice on what to do when you do find yourself in such a situation. It would seem as if there really is nothing you can do about it, just pray it never happens to you.

And three, as has been said by the other posters, work on your buoyancy control in the shallows, until being knocked off the upline doesn't result in a rapid ascent.

Sure, this is a good idea irrespective. There are many others reasons than reverse block to have your buoyancy well under control also.

But to get back to my original fear. What happens if you have not gone diving with any signs of congestion, you have watched the video by Dr. Kay and you have your buoyancy well under control but you find yourself 5m from the surface with reverse block? At some point you're going to have to swim through the pain and rapture your ear drums as it seems, there is nothing you can do to undo the reverse block?

 

[TSandM]

There is nothing you can do to undo the reverse block. The only thing you can try is to ascend very, very slowly and hope that a little air can squeak out. The maneuvers used for equalizing on land, like yawning or swallowing with the mouth open, can help try and open the Eustachian tube, but if it is swollen shut, you'll have to endure the pain and eventually surface. Better ear damage than drowning.

Reverse blocks are uncommon, for the reason already stated -- Positive pressure tends to OPEN the Eustachian tube, unlike on descent, where the negative pressure tends to suck it closed.

I've had one reverse sinus block, and I managed it by going back down a few feet and coming up much more slowly the second time. I was lucky. I was diving on the tail end of a cold, and deserved what happened to me!

 

[Damselfish]

I think I've had this happen 2-3 times; always when I was a bit congested but dove anyway. (On one of those occasions I was taking the 4-6 hour regular Sudafed and I think it ran out. I now stick to the 12 hour version if I'm going to do that.)

Descending a little and trying again is certainly something you can do, I'm pretty sure this was in my OW manual actually. Descend a little until your ears are happy agin. Take a break if you can and try to relax things instead of trying to ascend again immediately. Don't ascend too far all at once when you do. Ascend really really slowly. It may take many tries. If you get to 15 feet when divng from a boat with a hang tank, take advantage of it. Take advantage of your buddies air if they're got more than you. (Naturally this requires your buddy being there, and you communicating your problem, and you both having good control over your buoyancy.) The chance of this is one of many arguments for not cutting your air too close.

If you're not diving congested, and don't ascend rapidly, I don't think you have much to worry about.

 

[Scuba Ken]

If I feel a reverse block starting I hold my nose and try to breath in through it rather than blow out. This seems to provide some help in the air getting out.

 

[Doc]

I I feel a reverse block starting I hold my nose and try to breath in through it rather than blow out. This seems to provide some help in the air getting out.

Ken, that's about it.

Descend to 5 or 9 feet, until the pain abates....
Then pinch and suck. Reverse val salva.

Massage the blocked tubes by gently chewing, opening and closing the mouth, etc. while doing the pinch and suck.

If you can operate without your mask, massage the soft tissues above your eye sockets (under the brow ridge) as you do this.

You are trying to drain the sinus cavities of air that you forced in there during equalization. Now, at the surface, it has expanded and because the connective tissue tubes the channel the air (and fluids) into your throat, mouth, behind your eyes, etc... they're all jammed up and constricted with goo. You want to deflate these little balloons before you get the ice cream headache without the sprinkles.

That's the technical medical explanation... pinch and suck. That will get you out of the water so you can look at long term solutions.