Immersion Pulmonary Edema in dive accidents

[Duke Dive Medicine]

Lay-responders who know CPR and have received rescue training are already in a very good position to render the appropriate first aid care to a diver complaining of respiratory problems. EMTs and paramedics are primarily concerned with stabilizing the patient and expeditious transport to a hospital. Knowledge of IPE won't typically affect any of the interventions that they will attempt. Emergency room physicians may not have heard of IPE in the context of scuba diving, but they are certainly aware of how to treat pulmonary edema.

BubbleTrubble has once again summed up my thoughts better than I could have. In the field, pulmonary edema is pulmonary edema. The etiology is irrelevant to first responders and, to a large extent, even ED personnel.

Jax, I applaud your efforts to educate ScubaBoard readers about IPE. I do think it's necessary to re-emphasize the fact that, for the average diver/potential rescuer, the treatment in the field is going to be no different than the treatment for any other type of respiratory distress, as had been pointed out by numerous posters. I think that your emphasis on treatment should focus on "C - A - B", providing O2 if available, and getting the victim to the nearest hospital as soon as possible. The advanced treatments you talk about, e.g. bag valve masks and CPAP machines, are out of the scope of practice of most lay rescuers. Though they may be effective, if you include advanced ventilation techniques in a general discussion about IPE among divers it tends to muddy the issue.

It's also important to remember that, though IPE is still under investigation, we know that it is not a single, specific disorder. BubbleTrubble pointed out the probable differences between Denise's incident and John's. Similarly, IPE in a triathlete is different from IPE in a diver with underlying cardiac problems.

I do think that IPE is probably under-reported, possibly due to lack of knowledge. I'm glad to see that word of it is spreading, because the more it's recognized, the more it can be studied. We do need to avoid being alarmist, however, and remember the basics of first aid and CPR. In an emergency, it's those basics, executed well, that can make a difference in survival, as John's story vividly illustrates.

 

[Jax]

Jax,

I don't want to belabor the point, but this is incorrect information. The latest training for trained rescuers is just like the previous training, that is, 30 compressions to two breaths. "Compressions-only" CPR is for untrained rescuers only, that is, people who have not had a CPR class or been trained to get vitals on a speeding Baywatch boat.

Also, the term "slap on O2" is misleading. I asked you about it in the other thread and, as near as I could tell, you were saying that you were trained to put a high-flow O2 mask on a patient undergoing chest compressions. This, too, is incorrect. For a trained rescuer, proper administration of CPR involves providing compressions and ventilations, not compressions and high-flow oxygen via mask.

John (IntoTheDrink)'s incident highlights the importance of rescue breathing, which the divemaster gave him via a pocket mask. This needs to be differentiated, however, from "positive pressure ventilation", which, as BubbleTrubble has already explained, should be reserved for trained and experienced rescuers. Re mouth-to-mouth ventilations: the gross factor may put some people off, but so far, there has not been a reported incident of disease transmission as a result of direct mouth-to-mouth contact during resuscitation.

DDM - help me out with understanding this . . .

My classes have concentrated on - no pulse, go to Chest compressions, yell for help. You don't stop compressions to go for O2 for example. They stressed chest compressions over breathing -- then again, most of those classes were about dry land and you probably found a heart attack victim. (Army CPR / AED training)

Even in the rescue diver classes, it was "get on the chest compressions", and not apply O2 right away. IF there is someone else available, they were to do the O2, under your instruction if they were not trained.

We had an exercise in class, where the scenario was that you surfaced with a "diver", now take this glove and fill it like it were the diver's lungs, breathing 2x every five seconds. The exercise simulated rescue breathing while towing a victim. The class was thoroughly winded by the time they completed about a 40m swim. The message was, make a decision -- get the victim to the boat, and unless it is a very long time, don't waste time with trying to do rescue breaths while towing.

Now, let's make that an IPE victim - it seems like rescue breathing is far, far, more important than getting him towed to the boat right away.

So, as soon as you are on the boat, and don't feel a pulse, you go into chest compressions. I am thinking -- you just towed someone to a boat. You are winded and your heart is pounding fiercely. You can miss the victim's pulse, and start compressions, when all this time he cannot suck in air.

I hope I've explained this better . . . it seems to me - just a first aid provider - that if it is a scuba incident, the application of rescue breaths and O2 should be at least as important as chest compressions.

In 2010, the American Heart Association changed its long-held acronym of ABC to CAB — circulation, airway, breathing — to help people remember the order to perform the steps of CPR. This change emphasizes the importance of chest compressions to help keep blood flowing through the heart and to the brain.

The above makes perfect sense in a heart attack scenario . . . No so much in a diving incident. Reading John's and Denise's story, it seems like forever before they could breathe.

Is this a valid concern, or over-reacting to what is just a CPR application?

 

[Duke Dive Medicine]

Jax,

You've given a lot of different scenarios here. I'll try to answer as best I can.

First of all, I'm not a rescue diving instructor so I may have a different perspective, but if you're in the water with an unresponsive diver, I think that you have to assess the situation. How far are you from the boat? Is there someone else in the water with you who can help? Does the boat have a dinghy they can send, a life ring they can toss, a spare divemaster or competent diver who can swim out to help you? All those factors will influence how you care for the diver. In the best circumstances, ventilating a victim in the water is extraordinarily difficult. I've towed more than one unresponsive diver, and I can tell you that if you're having to physically tow a person any distance, it would be nearly impossible to provide effective ventilations while you're doing it.

You say, "now let's make that an IPE victim". How do you know that it's IPE? They don't come up wearing "Kiss me, my lungs are swollen" t-shirts. I'm not trying to be sarcastic, but the point that TSandM, Dandy Don, BubbleTrubble, I, and probably others I'm missing have been trying to make is that you don't know. Both Denise and John were diagnosed with pulmonary edema well after their respective incidents. In an arrest situation in the field, people with CPR and first-aid level training will treat the symptom, not the disease, because in most cases the cause of the arrest is not completely clear.

As for a victim who's on the boat, once again, you have to assess the patient and the situation. This isn't the right place to completely review basic life support, but if the diver is pulseless, a trained rescuer will perform compressions AND ventilations. I don't know what you learned in your rescue diver class and maybe I'm misunderstanding you, but "apply O2" implies placing an oxygen mask (e.g. simple face mask, non-rebreather mask, or venturi mask). You don't apply O2 to a pulseless and apneic patient like you would a conscious diver with DCS or mild difficulty breathing. You perform compressions and ventilations. Oxygen is used during resuscitation by trained individuals who may employ a bag valve mask or other device to assist in ventilations. Of course, if you're alone you're not going to stop compressions and ventilations to go fetch the O2 and hook up a BVM that you wouldn't be able to use by yourself anyway.

Regarding the "compressions only" technique: This is taught by the AHA and ARC in the hopes that even someone who isn't formally trained in CPR will at least jump in and do something. It's not, repeat not, intended for trained rescuers. Of course if the person arrested as a result of pulmonary edema, drowning or other respiratory issues, compressions-only CPR is not going to help.

In John's case, he was somewhat responsive and had a pulse, but he was not breathing effectively. He was given rescue breaths (NOT positive pressure ventilation) by a quick-thinking divemaster, which is entirely appropriate and probably saved his life. Again, the divemaster didn't know that John had pulmonary edema, he knew that he couldn't breathe, so he provided ventilations.

Hope this helps.

Best,
DDM

 

[Thalassamania]

It is really rather simple, two quick breaths, move to mouth to snorkel, transport. As soon as a stable platform presents itself, check pulse and add compressions if required. MTS permits transport as fast as is possible without ventilation, so nothing is lost.

 

[renoun]

Jax,

I don't want to belabor the point, but this is incorrect information. The latest training for trained rescuers is just like the previous training, that is, 30 compressions to two breaths. "Compressions-only" CPR is for untrained rescuers only, that is, people who have not had a CPR class or been trained to get vitals on a speeding Baywatch boat.

Perhaps you need to look in to the literature surrounding CCR rather than CPR. First a study that address passive ventilation with oral or nasal airways and 02 via non-rebreather using trained rescuers during compression only CCR. It turns out that adding a ventilation via BVM doesn't improve outcomes. More citations favoring compression only CPR follow. If outcomes aren't better why add complexity to the resuscitation process? Pulmonary edema must be one of the few situations where positive pressure ventilation would be beneficial but otherwise Jax isn't crazy discussing CCR without assisted ventilations and I believe she is a resident of Arizona where the first study I cite originated. DDM is correct is stating that in the current AHA Emergency Cardiac Care guidelines drowning is a situation where they recommend traditional CPR with assisted ventilation.

CONCLUSION: Among adult, witnessed, ventricular fibrillation/ventricular tachycardia, out-of-hospital cardiac arrest resuscitated with minimally interrupted cardiac resuscitation, adjusted neurologically intact survival to hospital discharge was higher for individuals receiving initial passive ventilation than those receiving initial bag-valve-mask ventilation.
Passive oxygen insufflation is superior to bag-valve-mask ventilation for witnessed ventricular fibrillation out-of-hospital cardiac arrest.
Bobrow BJ, Ewy GA, Clark L, Chikani V, Berg RA, Sanders AB, Vadeboncoeur TF, Hilwig RW, Kern KB.
Ann Emerg Med. 2009 Nov;54(5):656-662.e1. Epub 2009 Aug 6.
PMID: 19660833 [PubMed - indexed for MEDLINE] (full text here)

​

CONCLUSION: Instituting the new cardiocerebral resuscitation protocol for managing prehospital cardiac arrest improved survival of adult patients with witnessed cardiac arrest and an initially shockable rhythm.
Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest.
Kellum MJ, Kennedy KW, Ewy GA.
Am J Med. 2006 Apr;119(4):335-40.
PMID: 16564776 [PubMed - indexed for MEDLINE]


​

Conclusion
In adult patients with a witnessed cardiac arrest and an initially shockable rhythm, implementation of an out-of-hospital treatment protocol based on the principles of cardiocerebral resuscitation was associated with a dramatic improvement in neurologically intact survival.
Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest.
Kellum MJ, Kennedy KW, Barney R, Keilhauer FA, Bellino M, Zuercher M, Ewy GA.
Ann Emerg Med. 2008 Sep;52(3):244-52. Epub 2008 Mar 28.
PMID: 18374452 [PubMed - indexed for MEDLINE]

​

Conclusions
Survival-to-hospital discharge of patients with out-of-hospital cardiac
arrest increased after implementation of MICR as an alternate EMS protocol. These
results need to be confirmed in a randomized trial.
Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest.
Bobrow BJ, Clark LL, Ewy GA, Chikani V, Sanders AB, Berg RA, Richman PB, Kern KB.
JAMA. 2008 Mar 12;299(10):1158-65.
PMID: 18334691 [PubMed - indexed for MEDLINE]
Free Full Text at JAMA

​

Conclusions
This report demonstrates that if powerful cardiac compressions are started early, in this case less than two minutes after normothermic arrest, it is possible to maintain circulation and a sort of spontaneous respiratory movements resulting in gas exchange for more than 25 minutes. For this patient, this kind of respiration was sufficient for survival without neurological damage.
Favourable outcome after 26 minutes of “Compression only” resuscitation: a case report.
Steen-Hansen JE.
Scand J Trauma Resusc Emerg Med. 2010 Apr 16;18:19.
PMID: 20398354 [PubMed - indexed for MEDLINE]
Free Full Text from PubMed Central

Citations lifted from Rogue Medic's blog

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[Duke Dive Medicine]

Hello Renoun,

I'm familiar with the literature. It's part of the reason that AHA went to "C - A - B" vice "A - B - C"; beginning compressions immediately and minimizing interruptions has become a central focus of resuscitation. We'll have to wait and see if the C - A - B protocol changes outcomes any. I'm not bashing Jax for talking about compressions-only CPR, it certainly has its place. I was questioning how she was trained in her rescue diver course. The AHA ECC guidelines that you cited clearly state that for trained rescuers (including, presumably, rescue divers), the proper procedure is to perform both compressions and ventilations. This applies not only to drowning but also to any cardiac arrest. A waterborne situation increases the likelihood that the arrest is respiratory in nature, which only reinforces the need to provide ventilations in addition to the compressions.

Best regards,
DDM

 

[Hatul]

It's been pointed out already, but to reiterate, in drowning accidents the primary problem is hypoxia, and pumping around hypoxic blood is not going to help. You need to get oxygen into the body.

 

[agilis]

I was hospitalized for multiple pulmonary emboli last year following minor same day surgery. I complained about being a little short of breath just befor going home, and the MDs seemed extremely worried after the subsequent CAT scan they ordered. They kept me in hospital for two long weeks with IV heparin, and 4 months after discharge on blood thinners. I'm perfectly fine now, but has this experience made me more susceptible to IPE?

 

[Jax]

BTW - I wasn't ignoring this, but it hadn't appeared when I posted my post 30 minutes after.

BubbleTrubble has once again summed up my thoughts better than I could have. In the field, pulmonary edema is pulmonary edema. The etiology is irrelevant to first responders and, to a large extent, even ED personnel.

Jax, I applaud your efforts to educate ScubaBoard readers about IPE. I do think it's necessary to re-emphasize the fact that, for the average diver/potential rescuer, the treatment in the field is going to be no different than the treatment for any other type of respiratory distress, as had been pointed out by numerous posters. I think that your emphasis on treatment should focus on "C - A - B", providing O2 if available, and getting the victim to the nearest hospital as soon as possible. The advanced treatments you talk about, e.g. bag valve masks and CPAP machines, are out of the scope of practice of most lay rescuers. Though they may be effective, if you include advanced ventilation techniques in a general discussion about IPE among divers it tends to muddy the issue.

It's also important to remember that, though IPE is still under investigation, we know that it is not a single, specific disorder. BubbleTrubble pointed out the probable differences between Denise's incident and John's. Similarly, IPE in a triathlete is different from IPE in a diver with underlying cardiac problems.

I do think that IPE is probably under-reported, possibly due to lack of knowledge. I'm glad to see that word of it is spreading, because the more it's recognized, the more it can be studied. We do need to avoid being alarmist, however, and remember the basics of first aid and CPR. In an emergency, it's those basics, executed well, that can make a difference in survival, as John's story vividly illustrates.

 

[Bubbletrubble]

I was hospitalized for multiple pulmonary emboli last year following minor same day surgery. I complained about being a little short of breath just befor going home, and the MDs seemed extremely worried after the subsequent CAT scan they ordered. They kept me in hospital for two long weeks with IV heparin, and 4 months after discharge on blood thinners. I'm perfectly fine now, but has this experience made me more susceptible to IPE?

@agilis: Are you aware of the differences between pulmonary edema and pulmonary embolism?
In the vast majority of cases, the disease process causing each condition is entirely different. That being said, there is a small patient population out there afflicted with chronic thromboembolic pulmonary hypertension. FYI, it's thought that pulmonary hypertension predisposes a patient to pulmonary edema. Chances are this would not be relevant to you, though.

One well-described risk factor for pulmonary embolism is recent surgery (particular orthopedic or neurological in nature)...so in a sense your pulmonary embolism episode may have been somewhat "explainable." I'm not sure if your specific "minor same day surgery" would qualify, though. Hopefully, your treatment team discussed the potential causes of your pulmonary emboli, the probability of it happening again, and whether any long-term damage to the lung tissue occurred. Such issues should have been reviewed/considered as part of the decision-making process in granting you medical clearance to dive (after your hospital stay).

As far as I know, there is no published study (or case report) showing any evidence for an increase in IPE susceptibility in divers with a history of pulmonary embolism.

I'm not a pulmonologist. If you have any further questions, feel free to consult a pulmonary specialist.