bi pap?

akulahawkRN, ADN, RN, EMT-P · Oct 10, 2014

The patient is going to be headed down a path toward respiratory failure and isn't doing well, or is continuing to decline even while breathing O2 by mask. In other words, they're in that small window between using a non-rebreather mask and heading toward being intubated for respiratory support. Sometimes by putting someone on CPAP or a Bi-PAP, the patient gets to avoid intubation and being put on a ventilator. Their labs will probably show impending respiratory failure.

GrannyRRT · Oct 11, 2014

ABGS are deceiving. Many ABGS will appear to have normal numbers but the patient may be working hard. By the time the ABGS show impending failure you may have lost the window of opportunity for BIPAP.

Also remember that very few COPD patients are CO2 retainers. Impaired gas exchange and V/Q mismatch would be more appropriate terms which give you more disease processes to consider. For COPD, something like pneumonia, cardiac issues or sepsis could be at the root of the exacerbation. You also should understand hypoxemia, pulmonary vasoconstriction and deadspace as they pertain to increased CO2.

I would also consider getting a patient on BIPAP before a nonrebreather is needed. This mask is considered low flow and limits the flow available to the patient. Once a patient nears an FiO2 requirement of 0.50 with increased work of breathing, BIPAP should be considered.

JeanOfAllTraits · Oct 12, 2014

The thing that I love about our BiPaps, and iI'm not sure if this is how all of them work, is that they can have a back-up rate programed in. So that pt working too hard to maintain a rate that keeps their acid base balance looking nice now won't need to work quite so hard because we're gonna give them a few extra 'breaths' in the form of pressure, they just have to open up.

GrannyRRT · Oct 12, 2014

The thing that I love about our BiPaps, and iI'm not sure if this is how all of them work, is that they can have a back-up rate programed in. So that pt working too hard to maintain a rate that keeps their acid base balance looking nice now won't need to work quite so hard because we're gonna give them a few extra 'breaths' in the form of pressure, they just have to open up.

BIPAP machines are not meant to be ventilators. Since you used the term "backup rate" what I am about to say probably applies to your machine. Most of this is directly from the Phillips/Respironics website and can also be found in the manuals which are available online.

The rate setting on the BiPAP is designed to ensure a backup rate if the patient becomes apneic. The recommendation for*setting this rate is 8 to 10 BPM. The potential problem with setting too high a backup rate is patient-to-ventilator asynchrony, as these breaths are time triggered and cycled.

Spontaneously triggered breaths are preferable when possible, as the patient has full control of the inspiratory time. For example, if the rate is set at 15 BPM and the patient's rate is equal to or less than 15 BPM, the ventilator will deliver a backup breath, using the set inspiratory time setting, every*four seconds. NIV is designed around a spontaneously breathing patient, so setting the rate higher than or close to the patient's spontaneous rate is more like PCV.

Clinicians may think that setting a high rate will lessen the work of breathing for the patient. However, if the machine is set to deliver a minimum rate that is higher than the patient's spontaneous rate, the patient is denied the ability to trigger and cycle the breath when desired. There are times when this is necessary, but whenever possible, it is better to allow the patient to trigger the breaths and thus have control over the inspiratory time.

The Auto-Trak algorithm on the BiPAP Vision and BiPAP Focus provides optimal patient-to-ventilator synchrony, continually adjusting trigger and cycle thresholds to maintain patient synchrony. Auto-Trak adjusts to changing leaks and breathing patterns. If the rate setting is equal to or above the patient's spontaneous efforts, the beneficial auto-adaptive functions of the Auto-Trak algorithm are very limited. When*patients are*not comfortable with the rate or the I-time setting, they may fatigue due to decreased patient-to-ventilator synchrony and increased WOB. Patient-to-ventilator synchrony is critical to NIV success.[

Essentially you can cause a patient to fail by trying to "blow off" CO2 with a high rate. COPD patients need time to exhale and with these machines you can not always see air trapping or monitor intrinsic PEEP.

This is also why some BIPAP machines like the Vision alarms alot and some will just shut off (not a good idea) the alarms rather than understanding they have created the problems. The apnea alarm and the tidal volume are usually troublesome since the machine is not seeing any spontaneous breaths at a high rate and the tidal volume alarms happen when patient and machine are out of synch.

If these machines are used inappropriately and something detrimental happens to the patient, they have a long electronic memory which stores alarms and settings. Unfortunately a few RTs who tried to use the defense of "just following orders" have be embarrassed or worse.

JustBeachyNurse, LPN · Oct 12, 2014

ABGS are deceiving. Many ABGS will appear to have normal numbers but the patient may be working hard. By the time the ABGS show impending failure you may have lost the window of opportunity for BIPAP.
Also remember that very few COPD patients are CO2 retainers. Impaired gas exchange and V/Q mismatch would be more appropriate terms which give you more disease processes to consider. For COPD, something like pneumonia, cardiac issues or sepsis could be at the root of the exacerbation. You also should understand hypoxemia, pulmonary vasoconstriction and deadspace as they pertain to increased CO2.
I would also consider getting a patient on BIPAP before a nonrebreather is needed. This mask is considered low flow and limits the flow available to the patient. Once a patient nears an FiO2 requirement of 0.50 with increased work of breathing, BIPAP should be considered.

OT to thread but this just demonstrates the knowledge and skill of a qualified, experienced RRT and the importance of qualified respiratory therapists contribution to the healthcare team. Thanks

JeanOfAllTraits · Oct 13, 2014

Thanks RRT! You've inspired me to tall with one of our RTs this week to better understand the workings of our Bipaps amd the settings. I only mentioned the 'back up rate' because that's what our most recent attending was referring to when discussing our attempts to wean a chronic vent dependant trach patient.