No more mouth to mouth for heart attack?

[fisherdvm]

Definitely needs TSM input on this. I think this has been in the work for a while - but must've been recently publicized.

I guess a study in Japan on several thousand heart attack victims showed that chest compression alone has an impressive 50% better survival rate than standard CPR with rescue breath.

Comments?

 

[fisherdvm]

My guess is that even during chest compression, some oxygen is being exchanged between the lung and the pulmonary circulation. Or it could be that the pulmonary circulation is so poor with cardiac arrest, that the breathing didn't make a difference.

However, with the new change in CPR with faster compression, and changing the ratio to 2 breaths per 30 compression, it seems like we are heading in the right direction.

 

[Fish_Whisperer]

I just did a CPR course for Rescue. The ratio of breaths/compressions is no longer 2:15, but rather 2:30. Hopefully, the defibrillators will become more common in places other than just airports.

 

[H2Andy]

actually, there are many proponents of the "no rescue breath" CPR. i am not sure it has been implemented by any major agency, but it's certainly been talked about. we had a thread on here a while back.

basically, they feel more people would give CPR if rescue breaths weren't involved (fear of AIDS and other diseases)

and also it is thought that the compressions alone can get sufficient O2 to the brain through circulation

here's an example of the argument:

http://www.heart.arizona.edu/news-info/releases/cpr2.htm

 

[cbborromeo]

FisherDVM, 5The 50% increase in survival rate indicates that providing chest compression is better than doing nothing at all. Most bystanders aren't willing (for whatever reason) to give traditional CPR, which involves mouth-to-mouth recussitation.

Some facts:
Less than 1/3 of people who collapse in public are helped by a bystander.

Bystanders are less likely to help because the thought of mouth-to-mouth is off-putting or for fear of catching an infectuous disease.

In some cases, bystanders give mouth to mouth improperly which wastes valuable time that would better be spent giving chest compressions.

If a person collapsed because of a heart rather than a lung problem, they may have enough O2 in their body to survive for a short period of time without mouth-to-mouth.

The Japanese study recommends that the general public who have no CPR training should provide chest compressions (100 per minute) only rather than provide incorrect help or no help at all.

People who have proper CPR training should continue the current CPR method, which is still recommended by the Heart Foundation. Makes sense considering we all need O2 to stay alive.

 

[mikerault]

If you do the chest compression as hard as you are supposed to there will be air flow in and out of the lungs anyway from what I have seen.

 

[fisherdvm]

This actually might be a great advancement in rescue care. I mean, it doesn't matter if it is a choking victim, an electrical shock victim, heart attack victim, etc.... Just pump away.

Chest compression effectively perform the heimlich, and certainly, there has been accidents where you couldn't pay me enough to do mouth to mouth on.

Chest compression can be performed by almost anyone - including a kid.

You don't have to worry about over inflating the stomach with rescue breath, and end up with the patient aspirating vomitus.

 

[Fish_Whisperer]

Yeah... When they vomit, it's bad.






Especially if they haven't eaten anything that you like.

 

[rakkis]

If you do the chest compression as hard as you are supposed to there will be air flow in and out of the lungs anyway from what I have seen.

There really isn't any net movement of air from just compressions. Just quick, short flow out of the mouth/larynx; so you end up just exchanging out from dead-air space.

 

[fisherdvm]

There really isn't any net movement of air from just compressions. Just quick, short flow out of the mouth/larynx; so you end up just exchanging out from dead-air space.

You are right, Rakkis, at least in the pig model:

Ventilatory strategies affect gas exchange in a pig model of closed-chest cardiac compression
Auteur(s) / Author(s)
WHITEHURST M. E. (1) ; BLOUNT A. D. (1) ; AUSTIN P. E. (2) ; CARROLL R. G. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Departments of Physiology and Emergency Medicine, East Carolina University School of Medicine, Greenville, ETATS-UNIS
(2) Durham Regional Hospital, Durham, NC, ETATS-UNIS

Résumé / Abstract
Study objective: To identify the arterial and mixed venous blood gas changes caused by different ventilatory strategies during resuscitation from ventricular fibrillation in a pig model of closed-chest cardiac compression. Methods: A prospective randomized animal study was performed using 27 domestic pigs (body weight, 30 to 35 kg). Pentobarbital-anesthetized pigs were assigned to receive one of three treatments : (1) chest compression without assisted ventilation (n=8), (2) assisted ventilation with room air (n=8), and (3) assisted ventilation with 100% oxygen (n=8). A fourth group, with the airway completely blocked, was added at the end of the experiment (n=3). After instrumentation, the ventricles were fibrillated, and chest compression was begun 30 seconds after fibrillation with the use of the Thumper Mechanical CPR system (Michigan Instruments). Arterial and mixed venous blood gas samples were collected at 1, 3, 10, and 20 minutes of resuscitation. Defibrillation was attempted after the 20-minute sample was taken. Results: Fibrillation followed by chest compression alone caused a significant drop in arterial and mixed venous partial pressure of oxygen (PO[2]) and a significant increase in arterial and mixed venous partial pressure of carbon dioxide (Pco[2]). Compared with the chest compression only, ventilation with room air significantly increased arterial and mixed venous PO[2] and decreased arterial and mixed venous PCO[2]. Ventilation with 100% oxygen further increased arterial and mixed venous Po[2] but did not affect PCO[2], when compared with room air ventilation. The only successful defibrillations (3 animals) occurred in the group receiving 100% oxygen. Conclusion: This study indicates that passive air movement during chest compression does not allow physiologically significant pulmonary gas exchange and that room air ventilation alone is not sufficient to maintain mixed venous Po[2].