COPD & Emphysema Support Group

Pursed Lip Breathing (or "PLB" is a very popular and excellent "Rescue" technique for the acute dyspnea resulting from COPD, Emphysema and Asthma. However, in some cases of severe COPD and Emphysema, and chronic severe Asthma, it may enhance breathing comfort if used in a chronic long term manner. Generally however, breathing control techniques are more desirable for chronic, long term breathing comfort.

First, you need to understand some traditional theory as to why this technique works. Refresh your memory on the concept of Dynamic Bronchial Compression, and the collapsing of your airways on expiration, as your lungs are getting smaller as you breathe out. And recall that this is a particularly serious problem in people with Emphysema, as the elastic supporting lung structure helping to keep the airways open is deficient.

Pursed Lip Breathing simply imposes a slight obstruction to expiration air flow at the mouth, which generates a back pressure throughout the airways, and therefore a stenting effect to help prop open the airways and assist expiration and lung emptying. It must be emphasized, the amount of pressure supplied by you by pursing your lips together must, as usually described, be "minimal," or "gentle."

Specifically this mouth back pressure must be in the range of only 5 to 10 cm water pressure, and that isn't very much. If you compress your lips too much and exceed this minimal pressure, you will actually provide an expiration airway obstructive situation and impair air flow and lung emptying.

As generally taught, breathe in through your nose (to warm and humidify the air, and remove particles and bacteria), and then on expiration pucker your lips together as though you are whistling, to provide the desired mouth back pressure, and breathe out through your pursed lips in a "prolonged" manner. The length of prolongation is often stated to be two or three times (and occasionally four times) longer than inspiration. To practice correct lip pursing people are often instructed to place a candle about 4 to 6 inches away, and to make the flame gently bend or flicker, but never so hard as to blow out the flame.

Practicing in this manner is not very precise as to either mouth pressure or the all important length of expiration. A more realistic and precise way of practicing is by using the Breathing Trainer in conjunction with candle blowing.

For normal breathing, use your regular Breathing Trainer prescription. For "Rescue" breathing practice from acute overinflation dyspnea, set the Respiratory Rate at least two or three breaths less than your usual, and also set the Inspiration Time 5 or up to 10% less than your usual (i.e. your desired expiration time prolongation will therefore automatically be set 5 to 10% longer). Five or ten breaths of this Rescue pattern should get your lungs deflated, and you can then resume your normal breathing pattern. This Rescue pattern is also a good technique to be used temporarily during exertion, such as hurrying to cross a street or climbing stairs.

There is a common and serious problem with Pursed Lip Breathing, and that is the frequent reaction for people distressed by shortness of breath who preform tight-lipped and straining PLB, and therefore with excessively high PLB back pressures. This will immediately make their breathing situation worse. This is a very tragic paradox, as it is a natural tendancy for people to believe that if PLB works beneficially, then harder PLB will work better. And unfortunately lip puckering in the whistling position makes it very easy to slip into a tight mouth, straining, high pressure type of breathing.

A better solution to this problem is not to make the "whistling pucker," but instead to gently press the center of the lips together, and permit the air to escape through both sides of the lips. To do this more effectively, the cheeks should be relaxed. Doing PLB in this manner it is more difficult to switch into a tight, high pressure PLB situation.

And there is another major advantage to this modified PLB technique. By placing a straw through the central portion of the lips the mouth pressure can now be easily and directly measured with a suitable pressure guage. By watching the guage you are now able to do direct visual biofeedback training to achieve the desired 5 to 10 cm H2O back pressure, and to learn specifically what that pressure feels like, and therefore how to sense when you are pursing your lips correctly.

This same system can also be used to demonstrate and recognize the common problem of excessive tight-lip, high back pressure PLB, by having the patient strain at 20 to 30 cm H2O, to get the sensation of how not to do PLB. Once patients know this high pressure sensation, it then becomes an easily recognized signal of poor PLB technique that needs correction.
.....Dr.Deane Hillsman....
Posted on 06/23/07, 06:06 pm