Well it's winter time again and the downward trend in mercury levels has given rise to increasing numbers of URI's presenting in EDs. And with more URIs, naturally, come more asthma exacerbations.
Like any other chronic disease capable of flare-ups asthma exacerbation exists within a spectrum of severity. The emergency physician's management and level of aggression in treating asthmatics should parallel degree of acuity. Certainly, we wouldn't intubate an asthmatic speaking in full sentences with adequate saturation just as we wouldn't halt efforts at albuterol/atrovent on someone tripoding for air.
After reviewing current literature*, trends, guidelines, and expert opinions** I've compiled my 4 S's of Asthma management in the ED, a useful tool to guide a physician through a progression of pointed care.
1. Smoke: Alluding to the tell-tale hissing mist of nebulized ("nebs") bronchodilators, this first-line modality is indicated for all-comers in exacerbation and--like high-quality chest compression and defibrillation in ACLS--is your most important disease reversing therapy. When severe, keep the smoke flowing.
The short acting bronchodilator albuterol is no worse than it's isolate counterpart levalbuterol. Add anticholinergic ipratropium bromide (atrovent) to your first 3 doses only (adults).
|Product currently only available in California and Mexico|
|"It's for asthma. Swear."|
3. Supplements: analagous to the potpouri GNC packets of vitamin and mineral supplements taken by some, this refers to the various medical therapies we throw at patients in severe exacerbation. Like the GNC pills, the following list of commonly used modalities may be effective but are less substantiated in literature. They are indicated for use in severe exacerbations only. When smoke and steroids aren't cutting it, reach for:
- Magnesium sulfate: calcium channel blocking properties, it helps bronchodilate. No benefit in mild-moderate asthma.
- Epinephrine: adrenergic effect increases bronchodilation. Caution in patients over 40 or those with underlying CAD/PVD
- Terbutaline: essentially similar to epinephrine (may substitute)
- Ketamine: is there anything this drug isn't good for? Use here for anxiolysis and bronchodilation. Use smaller doses (1 mg/kg IV)
|"Crap. Which one's the cyanide again?"|
4. Support: Inspiratory support, that is. If you've gotten this far down the list your patient is likely tripoding, tachycardic, diaphoretic, pale, and relatively close to buying the plastic (intubation). While the literature is not strong (no RCT to date) to support it, there are numerous case studies--not to mention personal experience--showing benefit to BiPAP in critical asthmatics with signs of diaphragmatic fatigue.
Be sure to minimize PEEP (EPAP) to the lowest allowed setting (their alveoli are super-recruited as is) and start at a generous IPAP of 8-10 cm H20 to remove any burden of poor diaphragm contraction from the failing patient. Make sure to keep nebs flowing through the BiPAP!
|The IPAP is the counter-weight assist. The tired arms are the diaphragm. More IPAP is more counterweight.|
That's it! Try it out and let me know what you think.