i have a question. it seems like regardless what i do, it seems wrong. i've came across a COPD pt with diff breathing(according to the NH). They are on 2LPM O2 via NC with sat's at 86 and RR at about 26/min. now here is where i have a problem. do you leave them on the canula at 2LPM, or do you put them on a NRB and up the flow. i've txp with the canula and when we got to the er they put them on NRB and i've txp after putting them on NRB and got to the er where they put them back on canula. granted i do know that high flow O2 is bad for COPDer's but my understanding was that if it was bad only if you had them on high flow for an extended period of time.
As stated, do not withhold oxygen.
There are many types of COPD patients and less than 5% within this classification are CO2 retainers. Long term COPD patients will almost always have some type of cardiovascular problems which must also be treated by O2 because their potential is more deadly than a person becoming somnolent. You are trained in the use of a BVM for those that do become somnolent or have depressed respirations and it may not be because of the FiO2 you are giving.
That NC can also go up to 6 L/m.
If your instructors would take time to explain how minute volume influences FiO2, it would make things clearer.
If a patient is accustomed to breathing at a minute volume of 6 L/m on a NC at 2 L/m and then their minute volume become 12 L/m, the NC may have to be increased to maintain the same FiO2. The textbook values for FiO2 at the different liter flows are for a normal patient breathing a textbook normal minute ventilation at rest without distress. The patient may not need that much more O2 but just enough to keep their inspired FiO2 within a good range.
For a person with a greatly increased minute volume or each tidal volume, that 2 L of O2 with be diluted to almost 21% or room air.
If you put that same 2 liters or even 1 liter on a baby by NC, you may be meeting their entire minute volume and are delivering almost 100% O2. That is why blenders mixing air and O2 are used for them when they way NCs. If the blender is set at 28%, a 1 liter NC can give a small baby close to 28% with little dilution from the room air.
A litte side note, for a patient to qualify for home O2 by insurance standards, including Medicare, we have to document an SpO2 of less than 86% or a PaO2 of 55 mmHg. However, that does not mean they should stay at that level which is the reason for the home O2. Many complications occur if their body stays at a very low PaO2 for any length of time. Some are sensitive very quickly if their PaO2 drops for any length of time if they also have cardiovascular problems.
If you get involved in IFTs of almost any type, you should become familiar with the different classifications of O2 equipment. A "true" high flow device may not always deliver a high FiO2.
A venturi mask is a high flow device even if it is running at what EMS providers believe to be low flow. This is because venturi masks are able to provide total inspiratory flow at a specified FIO2. A NRBM cannot always do that and is considered a low flow mask.
The amount of oxygen going into the O2 device does not necessarily mean it is a high flow or even low flow device. The device must be able to provide the total inspiratory flow. Thus, devices are classified whether they meet the true definition of flow and by their FiO2 delivery. However, air entrainment systems may have their limitations at some point.
Study how you O2 device works and you won't have to rely on memorizing a recipe for each situation. Learn gas laws, oxyhemoglobin dissociation curve, venturi effect and bernoulli's principle.
Here's some good reading:
http://www.dmacc.cc.ia.us/instructors/kegeorge/prac5/Oxygen.htm
http://www.salisbury.edu/healthsci/resp/classes/lrjoyner/fall/RESP301/O2Tx.htm
This is the explanation the medicine world is leaning toward for an explaination for increased PaCO2 in a COPD patient.
High levels of O2 may disrupt the normal V/Q balance, causing an increase in the VD/VT ratio and a rise in paco2.
AARC O2 guidelines for Peds and infants
http://www.rcjournal.com/cpgs/soddnppcpg-update.html
AARC - adults
http://www.rcjournal.com/cpgs/otachcpg-update.html
AARC - Homecare or Nursing homes and LTC facilities
http://www.rcjournal.com/cpgs/pdf/08.07.1063.pdf
Hypoxic Drive theory disputed for other causes
http://www.rcsw.org/Download/2004_RCSW_conf/The death of the hypoxic drive.ppt
Hypoxic drive references for those that might want more reading on the subject.
http://www.rcsw.org/Download/2004_RCSW_conf/The death of the hypoxic drive studies cited in.doc
One also must understand the relationship between ventilation and perfusion to provide effective O2 therapy.
Good Basic powerpoint:
http://www.clt.astate.edu/agrippo/RESPIRATORY DISEASESf03.ppt
http://www.cardionursing.com/pdfs/Ventilation-Perfusion-Diffussion-and-More.pdf
http://www.uams.edu/m2008/notes/phys/pdf/March 22 Ventilation Perfusion Relations.pdf
For those of you who want a more advanced approach to ABGs or acid base analysis:
http://www.rcsw.org/Download/2006_RCSW_conf/Presentation 2006 RCSW Acid Base Analysis.ppt
Medicine is constantly evolving with new research published everyday. There may be not just one correct answer for every problem. However, if you don't understand the basic fundamentals or principles for any device or therapy, you will just be following a recipe.