1. When do you use non-invasive positive pressure ventilation (NPPV) in status asthmaticus?
2. Do you start inhaled corticosteroids on asthma patients who are going to be discharged from the ED?
3. When, if ever, do you use ketamine for induction, or for treatment without intubation, in status asthmaticus?
4. When do you use epinephrine in status asthmaticus and when do you avoid it?
EM Lyceum 
1. When continuous albuterol/atrovent, IV steroids, magnesium and supplemental O2 and IVF fail to improve or when the patient arrives in extremis.
2. For recurrent trips to our ED for exascerbations.
3. For induction, my agent of choice. For treatment without consideration of intubation, same as #1 When continuous albuterol/atrovent, IV steroids, magnesium and supplemental O2 and IVF fail to improve or when the patient arrives in extremes).
4. As a last resort as I do not see it adding anything significant to the treatment if continuous albuterol/atrovent, IV steroids, magnesium, supplemental O2, IVF, NIPPV and ketamine are failing.
1. Only in the rare patients non-responding to medical treatment, nebulized albuterol + ipratropium + steroids, O2, IV steroids, IV magnesium.
If NPPV, everything ready for ETI.
NPPV never in fatigued patients, too late, ETI better option.
2. Always.
Simpler than stratifying according to asthma control, since the vast majority of patients come to the ED for uncontrolled asthma
3. Ketamine for induction
4. Only in failing patients, not sure useful
1. Don’t do NPPV, their problem is usually getting air out not in, you could worsen their problem, better to not dick around and just intubate by then, if they sound like they’re having secretions can try inhaled racemic epi. Heliox may help for symptoms control.
Disagree. In theory, providing any sort of EPAP would increase the resistance for exhalation. However, intubation and mechanical ventilation relies solely on positive pressure ventilation. Even worse, it’s controlled by a machine. Your risk of breath stacking increases dramatically with positive pressure ventilation (unless you have time to continuously monitor their flow curve and disconnect them from the vent every time they start to stack). NPPV simply assists in negative pressure ventilation. In my experience, the reason people fail with NPPV (assuming all standard treatments are being implemented) is that they are not provided adequate anxiolysis, eg sub-dissociative doses of ketamine. They are building up CO2, which tells their brain to breath faster, when really what they need is to breath slower and expire trapped air, which can easily be done over EPAP of 5.
Jacob and Moab,
With respect, you guys are a bit off base here in the understanding of how non invasive ventilation works to help in the early stages of respiratory failure.
The the PEEP or what we refer to as the EPAP, is there to help alleviate the dynamic hyperinflation by applying enough extrensic peep to counter the intrinsic peep that develops from dynamic hyperinflation (seen in copd, asthma, and other obstructive disorders leading to respiratory failure). IPAP coupled with adequate EPEP should off load the mechanical load applied to the respiratory system.
Very well put by the following statement in an article I will link
“Pmuscle + Papplied = E(Vt) + R(V) + threshold load + Inertia
Pmuscle is the pressure supplied by the Inspiratory respiratory muscles; Papplied is the inspiratory pressure provided by mechanical means; E is the elastance of the system; R is the respiratory system resistance; Threshold load is the amount of PEEPi or intrinsic PEEP the patient must overcome before inspiratory flow can begin; Vt and V are the tidal volume and the flow rate respectively; Inertia is a property of all mass and has minimal contributions and thus can be ignored clinically.”
http://www.mcgill.ca/criticalcare/teaching/files/intubation
The purpose of using any positive pressure ventilation is the achieve resting of the mechanics as well as to improve gas exchange.
Breath stacking, as you point out, is a risk of any mechanical ventilation when the RR is to high to allow for adequate exhalation phase. In very severe respiratory failure such as that seen in asthma and copd, the stacking can be avoided with proper peep, adequate vent settings, and importantly, deeper sedation and pain control — the later helps with controlling rate for as long as you need. Usually a 12 to 24 hours of deep sedation is adequate.
Providing “adequate anxiolysis” is not a good idea in my opinion for MOST patients. I think there are a select few that you may be able to get by with it, though. Sedation typically does not fix the problem in my experience. However, I am a pulmonary and critical care doc, so I may not be seeing the same population. IE you may fix those patients and I may not get the chance to see them. I will say this, I have gone to many a floor intubations due to bipap being used on folks that were overly sedated. This is usually because the provider gets called by staff that the patient is not tolerating bipap…thus they get meds and it just makes things worse.
another good link is here
http://lifeinthefastlane.com/ccc/non-invasive-ventilation-niv-and-asthma/
With respect,
Craig Rosebrock MD
1. if / when bad looking patients do not rapidly improve with albuterol. earlier the better to potentially save intubation. Can take a patient off NIV much easier than you can take them off a vent.
2. only if there is poor access to primary care and have had to use albuterol more than twice a week.
3. I dont have much experience with K for asthmatics. Theoretically, I would use it for induction. If the patient wouldnt tolerate NIV well and I didnt want to jump to ETI, I’d consider K & run albuterol through NIV… Using DSI as a tool to not intubate gets into tricky & slippery territory rather quickly I would imagine…
4. If patients are gasping to the point that they cant get albuterol into their lungs, or if its from an anaphylactic response, then I guess thats when I would reach for epi. I thought I had seen someplace that albuterol is equivalent to epi, so no need to give it concurrently, but I could be wrong though.
Nippv- mod-severe Resp distress, tripod ding, access muscle usage not rapidly improved c neb
Inh ster – freq exacerbation a, poor pcp f/u
If inducing -rare occurrence, but every time if I have time (“paralytic” boxes have etom- working on that). If not for induction, given rapidly afterwards.
Epi – similar to bipap, severe with Resp distress, not responding to Nebs, headed toward tube. Only hesitate if >60 or known cad.