Sometimes the oxymizer is referred to as a “nasal moustache” because the reservoir is positioned under the nose, as in this instructive 1-minute video from RT Clinic.
What’s the conversion between oxymizer and nasal cannula?
Roughly 1:2––For example, 3 L by oxymizer delivers approximately the same amount of FiO2 that 6 L NC does. Some oxymizer devices can provide oxygen at a 1:4 level (so 1 L oxymizer=4 L NC) and deliver up to 20 L NC! Pretty cool.
What are the advantages of using an oxymizer?
For patients at home, oxymizers make portable oxygen tanks last longer (because the flow rate is lower). How much longer? It depends on the individual patient’s O2 needs and activity level. The lower flow rate also decreases nasal dryness and the discomfort of oxygen blasting into the nares all the time. From a pragmatic standpoint, most clinicians would be nervous about keeping patients at 7-8 L NC at all times (especially on a general medical floor), but an oxymizer can be used to keep patients with higher O2 requirements who are otherwise stable on the floor. For most patients with long-term, high-flow oxygen needs, oxymizers just make more sense.
If it’s “better” than nasal cannula, why don’t we use it all the time? Are there any downsides to the oxymizer?
Cost-wise, oxymizers can be expensive. Not all insurance companies cover oxymizers. The retail price of a single device is (as of this post) about $400 and the manufacturers recommend replacing the device every 3-4 weeks to ensure the membrane continues to work properly. In addition, some patients find the heavier tubing uncomfortable to wear. As far as I know, that’s pretty much it.
Disclaimer: I don’t get paid by Big Respiratory to write this. I have noticed more and more patients wearing oxymizers in the past couple of years who have been able to stay out of stepdown units and ICUs just because they “need more than 6 L NC, which is too much for the floor.”
A nurse runs into the workroom: “Ms. X’s trach is two inches out! She’s desatting to the 70’s on 60% FiO2!”
What do you do for a dislodged trach? This is the situation I faced a week ago, on a patient who wasn’t mine on the floor where I was working.
First, to clarify, dislodged=trach partially out of the stoma, decannulated=trach is all the way out of the stoma. Immature stoma is <1 week, mature stoma >1 week.
Your nurses and respiratory therapists are your life line!! Most institutions have protocols to page Anesthesia or a surgical team of some kind for these situations.
Bag valve mask=Ambu bag: whatever you call it, if a patient with a trach is in distress, stabilize them with manual respiration. Apply the bag to the trach itself. If you meet “resistance” while bagging, STOP. It indicates either the trach is in a false tract, or there’s an obstruction, like a plug or extra tissue. (If it’s a false tract, you might be able to feel subcutaneous crepitus develop during bagging!)
If bagging the trach doesn’t work, apply the bag to the patient’s mouth for face bag ventilation. The one caveat is laryngectomy patients: their mouths are not connected to the rest of their airways.
Remove the inner cannula. Insert the suction catheter. If the catheter quickly draws back secretions, it’s still in the right place. If it doesn’t, the trach might be in a false tract.
If you want to be fancy and have the skills, a fiberoptic scope can be passed from the mouth or through the stoma to look for problems.
If the stoma is mature, in an emergency you can replace the trach with one that’s the same size or one size smaller. However, if the stoma is immature, the rate of closure is very high–up to 50% of the hole can close within 12 hours!
Therefore, when dislodgement and definitely decannulation happens in an immature stoma, you may have to reintubate and wait for the surgeons to repair the stoma and reinsert the trach.
In my patient’s case, we ended up bagging her by mouth until respiratory therapy fiddled around with her trach enough to confirm it was in the right place and secured it with the trach collar. Stabilization is always #1! It turned out the patient had a large gap in her stoma, making the trach loose/malpositioned. The thoracic surgery team came by and put in a stitch to close the gap.
AKA “pulmonary hygiene.” Pulmonary toilet is advocated by many people, and does sound like a good idea in theory. However, the literature on whether pulmonary toilet actually improves outcomes for various patient populations is very mixed. In general, the patients who seem to benefit most are the cystic fibrosis and critically ill/intubated populations.
The purpose is to THIN and LOOSEN secretions. Having an awake, alert patient who can cough on their own is the best kind of pulmonary toilet.
What are the specific components of pulmonary toilet?
Mucolytic (such as NAC or Mucomyst): NAC in particular has become less popular because of lack of demonstrated utility (a good example is this meta-analysis on cystic fibrosis). I still see it used in the ICU, though.
Hypertonic (7%) saline: may cause bronchospasm, coughing
Deep tracheal suctioning gets lower respiratory secretions and can be very satisfying, but should only be done in intubated patients
Bronchoscopy: using a bronchoscope to “wash out” secretions for atelectasis. This is only helpful in patients who are critically ill/intubated who cannot do any other kind of secretion clearance on their own. My personal observation is that when BAL is used for pulmonary toilet, it turns into a problematic cycle of provoking even more secretions and the need for repeated bronchs. A bronch is also not a completely benign procedure and may be associated with barotrauma, temporarily worsened oxygenation, etc.
When is pulmonary toilet useful? This clinical review is pretty negative. It states that chlorhexidine oral rinses are the only intervention that reduces rates of nosocomial pneumonia, and that other common practices like mucolytics and chest PT are not associated with improved outcomes and may in fact cause harm like bronchospasm and mechanical trauma, respectively. (A lot of evidence comes from pre-2000’s papers/guidelines, though). Let’s look at some common situations:
COPD: This meta-analysis reports that daily oral NAC was associated with fewer COPD exacerbations in patients who had a spirometric diagnosis of COPD, but also in patients who did not have a spirometric diagnosis of COPD. However, this joint paper from ACP-ACCP states that multiple trials have not found benefit for mucolytics or chest PT in COPD exacerbations.
Cystic fibrosis:Yes to chest PT. There is also good evidence that dornase alfa (DNase) and hypertonic saline have small effects.
Atelectasis: for acute atelectasis, if patients cannot cough on their own, chest PT is helpful. (The same review talks about how “bronch for airway clearance” is only indicated in selected cases of atelectasis that are multilobar or severe.)
Post-surgical patients :There is very limited objective evidence that pulmonary toilet decreases pulmonary complications (pneumonia, atelectasis, edema, etc.) in the postoperative period. This Cochrane review shows that in patients who underwent upper abdominal surgery, incentive spirometry didn’t make a difference. Maybe this will make us feel better about all those unused incentive spirometers sitting by patients’ bedsides.