Wednesday, December 23, 2009

Indications for BiPAP

BiPAP is the new IPPB in the hospital, as it is used on a wide array of patients for a variety of reasons. With the advent of the BiPAP I have seen it prevent many patients from needing to be placed on a ventilator. However, I've also seen it used when it is not indicated, which is why I compare it now with the IPPB.

That said, I thought I'd write here some of the indications for BiPAP in the emergency room or in the hospital. Basically, it comes down to the following:
  • To improve ventilation. To blow off CO2 (IPAP)
  • To improve oxygenation. (EPAP)
That's basically it. You could get more technical and make a list like the following, but it all basically comes back to the above two:
  • Increased CO2 due to decreased airway resistance such as in COPD
  • Respiratory failure due to accessory muscle fatigue
  • Hypoxemia due to respiratory failure that results from pulmonary edema, atelectasis, pulmonary embolis, and pneumonia
In the case of all the above mentioned indications the ultimate goal is to get the patient over the hump so that more invasive ventilation (a ventilator) is not needed.
Contraindications would include the following. Pay attention to these, because I've had to remind doctors of these from time to time:
  • Inability of patient to protect his own airway (decreased level of consciousness)
  • Increased secretions (i.e. pulmonary edema, increased sputum production)
  • Any patient at risk of vomiting (post stomach surgery, drug overdose). In this case you may be able to use BiPAP if an NG is inserted.
  • Bullous lung disease (emphysema)
  • Pneumothorax. (this may be complication due to increased pressure)
  • Hypotension
  • non-compliant patient
BiPaP is the preferred method over CPAP. If you're goal is to improve oxygenation this can also be achieved by increased ventilation, so you might as well do both and use BiPAP (at least in the hospital setting).
I have seen BiPAP ordered on patients that do not fill the above indications. The following are some examples:
  • Pulmonary edema to force the fluid out of the lungs (CHF and pneumonia)  (Update:  T'his has actually been disproved by studies, as I reported on here.)
  • Hyperventilation (normal or low CO2, normal PO2)
  • Rising yet still normal CO2 on a patient in no respiratory distress.
  • To agitate the patient to increase the blood pressure.
As you can see from this post BiPAP can help a patient with pulmonary edema turn the table. Yet it is still not the BiPAP that is going to make the heart a better pump -- it's the medicine the doctor orders. The BiPAP treats the symptoms to buy the patient and doctor some time.

Hyperventilation is not an indication for BiPAP, and niether is a normal CO2. And if a patient has a low blood pressure they most certainly shouldn't be hooked up to a BiPAP. Sure it may increase intrapulmonary pressure, but it may also decrease the blood pressure and put the patient at an increased risk of having a heart attack (MI).

The following were used as references for this post:

Further reading:


Matt said...

"I have seen BiPAP ordered on patients that do not fill the above indications. The following are some examples: Pulmonary edema to force the fluid out of the lungs (CHF and pneumonia"

While BIPAP does not "force" the fluid out of the lungs, it's usage in treating acute pulmonary edema has been well documented in the critical care setting.

A high level of EPAP (ie + 1O, + 12) acts to decrease venous return thus decreasing ventricular preload and allows time for the left Ventricle to "pump" the pulmonary edema out of the lungs.

Anonymous said...

I heard bipap helps bradycardia....any thoughts on this?

Rick Frea said...

Never heard anything about that. Have you seen any studies?

Anonymous said...

Gollee gee willikers....

Respiratory therapists are so smart, and doctors are so dumb. We know nothing about respiratory care.

Is that the (nonsensical) point you're trying to make with your little quips about doctor 'mistakes'?

Perhaps you don't know as much as you think you do. Go to medical school, and find out for yourself.

Rick Frea said...

If I thought I was smarter than a doctor I'd be a doctor. The whole reason the respiratory profession was created (BY A PHYSICIAN) was because respiratory therapy was beyond the scope of the physician's knowledge (quote by EGAN). We RTs are the experts in respiratory therapy. That's all we do. We study it. We eat it. We live it. We are a part of the patient care team, and it's our job to make recommendations to the physician. Then the doctor makes the final decision. If anything, the reason I write stuff like this is our of respect for the medical profession.

Rick Frea said...

Thats respect for the medical profession, and respect for the patient. BiPAP is not fun to wear. And We RTs just want to make sure if it's going to be used, the doctor is aware of the facts.

Anonymous said...

Comments by the previous anonymous poster sound defensive, childish and quite unexpected from a physician.

Rick Frea said...

True, and it was anonymous, so it probably wasn't even a physician.

Anonymous said...

I have a relative recently put on BiPAP. He has Bullous Lung disease and you list this as a contraindication. Would you please post a medical reference so that I may educate myself before I consult the physician. Thanks

Anonymous said...

Hi. I think I misread your contraindication list. The contraindication was for bullous lung disease pneumothorax, not just bullous lung disease. If I'm wrong please post. Thanks again for an informative block on NPPV.

Anonymous said...

We use BiPap for acute pulmonary oedema all the time in conjunction with frusemide to extremely good effect. Why do you feel this is not an appropriate management?

Rick Frea said...

I am not opposed to BiPAP for heart failure. I am opposed to the myth that BiPAP will somehow force fluid out of the lungs. This is not true, as BiPAP decreases cardiac output and helps by that means. I added a link to the post if you wish to check it out: the 17 biggest myths of respiratory therapy. I explain this in more detail in the post. Thanks.

Robert22 said...

I work at a hospital where a physician orders Bipap, on 2 hrs, off 2 hrs as a therapy. Usually the patient has pneumonia or plural effusion. Any thoughts.