Asthma

From the Greek for panting

Early phase is from mast cell degranulation

Late phase is from inflammation-exposure of nerve endings

Exercise induced has no late phase

ASA Asthma-can cross react c APAP and NSAIDs

Tachycardia will diminish c improvement of obstruction even with B2s

Pulsus paradoxus=severe asthma

Decompensation: noncompliance, URI, viruses, pneumonia, med changes, heroin, cocaine

Treatment

MgSO4 in severe attack, it only helps in FEV1<25% predicted (CHEST 2002; 122:489497)

Methylprednisolone 125 mg IVPB or prednisone 60 mg PO

Proventil

5 mg Q 10 or continuous 10 mg in 70 cc NS over 1-2 hrs (better Jagoda)

5 mg dose better than 2.5 (Am J Med 105(1):12, 1998)

Albuterol MDI c Spacer equally as good (Chest 121:1036, 2002)

Nebulized B-Agonists will lower your potassium, magnesium, and phosphate (Annals of EM 21:11, 1992) and

Cydulka RK et al: Comparison of single 7.5-mg dose treatment vs sequential multidose 2.5-mg treatments with nebulized albuterol in the treatment of acute asthma. Chest 122:1982, 2002 can give 7.5 over 1 hour, much easier

In adults, no difference between normal and Lev albuterol (The American Journal of Emergency Medicine Volume 24, Issue 3 , May 2006, Pages 259-267)

Atrovent

Do not give atrovent or combivent inhalers to patients with peanut allergies as contain soy lecithin which cross reacts with peanut allergies in ~10% of cases. Nebs are not a problem.

Give 3 doses of 0.5 mg Q 20 min then as needed in the ED, not in the hospital (National Asthma Ed and Prevention Program Guidelines 2007)

Epinephrine

Epi .3-.5 mg SQ q 10 (Actually better to go into thigh IM Journal of Allergy and Clinical Immunology 108:5 2001)

same cardiac side effects between terbutaline and epinephrine (Chest 1975 67:279)

Nebulized Epinephrine

From Lech summary of EM:RAP lecture

There are a percentage of people with a polymorphic beta 2 receptor to whom terbutaline does not bind avidly
IV epi works just as well (used esp in Australia)
Dr. Weibe believes nebulized epi is better than IV epi because you are not exposing every adrenal receptor in the body to epi, and you are depositing a more concentrated dose where you want it, i.e. the respiratory mucosa
In Canada, L-epi is used (racemic epi is no longer available) – 5 cc of 1 in 1,000 concentration – that is 5 mg of epi
Nebulized epi – has the lowest side-effect profile compared to other routes of delivery
Prearrest patients will not be able to take a deep enough breath to get the benefits of nebulized epi, for those patients, give it parenterally
Racemic epi dose: 0.5 cc (comes in 2.25% concentration), put it with 1 cc of NS in a neb – total dose of 11 mg of epi
You can also use crash cart epi (use the 1 : 1000 concentration) and the dose is 5 cc – which gives 5 mg of epi

Terbutaline

Longer lasting than epi, but much slower onset. Use epi for first dose then switch to terbutaline. (ACLS EP)

.25-.5 mg SQ q 10 (no benefit over epi (Jagoda, Ann Emerg Med. 1997 Feb;29(2)))

Aminophylline

(Aminophylline dose x 0.8=theo dose)

every 1 mg/kg of aminophylline increases serum by 2 meq/ml

Nebulized Magnesium

The intervention involved administering a single dose of 2.5 mg (0.5 cc) of albuterol mixed with 2.5 cc of normal saline (A+S group) or 2.5 mg (0.5 cc) of albuterol mixed with 2.5 cc of isotonic magnesium sulfate (A+M group). Magnesium was supplied in the form of 6.3% solution of magnesium heptahydrate, which is equivalent to 3.18% anhydrous magnesium sulfate. These were nebulized with 810 L/min of oxygen. The study medications were provided in identical syringes and both the pharmacy and the investigator were blinded to their contents. All patients received 2 mg/kg of prednisone for asthma after their first dose of inhalation medication. (JEM July 2004 )

Systematic Review (Chest 2005;128;337-344) Steroids

can give one single IM injectionsof 160-mg methylprednisolone acetate (depo-medrol) and will equal efficacy of course of oral steroids (Chest 2004 AugChest 2004;126:362-8.)

Nebulized Lasix

no help in one shortcut review (Emerg Med J 2005;22:654)

Potential Mechanisms:

induction of relaxation prostoglandins
blockade of inflammatory mediators
regulation of ion exhange in the airway epithelium

Severe Asthma

Excellent Review (J Emerg Med 23:3, 257-268, 2002)

RSI

Pretreat c Lido 1.5 mg/kg

Atropine or Glycopyrolate

Ketamine 1.5-2 mg/kg

Sux

5 mg proventil down tube

Vent

permissive hypercapnea, 6 cc/kg, <10 bpm.

Raise Insp flow rate to 80-100 LPM,

If needed to overcome autopeep, can add peep up to 8.

Decel Flow Pattern instead of square

Drugs

Start Proventil 20 mg/hr along with atrovent

Refractory:

Terbutaline Drip-4 mcg/kg over 10 minutes followed by .04 to .2 mcg/kg/min (250 mcg over 10 minutes then 3-12 mcg/min)

Aminophylline 5 to 6 mg/kg over 20 minutes, followed by a maintenance infusion of .6 to .9 mg/kg/ hour (Not really done anymore)

Glycopyrolate .2 mg IVP

MgSO4 2-3 grams over 10-20 minutes

Ketamine Bolus 1.5 mg/kg then if needed repeat at 2 mg/kg or Infusion .5-2 mg/kg/hr

Heliox beneficial if high pressures in vented patients (Am J Resp Crit Care Med 165:1317, 2002)

Worst case-use general anesthesia (Halothane)

If patient can not maintain pH >7.2, consider Bicarb infusions to keep pH>7.2

Myopathy in asthma patients with non-depol paralytics especially with steroids (Jagoda Asthma Article JB19)

Consider Triple Therapy for Severe Asthma Prospective, Double Blind Add to combivent, flunisolide 1 mg Q10) or use Decadron 4 mg in Neb (Chest 123(6):1908, June 2003)

Isotonic Nebulized Saline resulted in improved FEV1 (Lancet 361:2114 June 21,2003)

Heliox

Heliox for asthma in the emergency department: a review of the literature (Emerg Med J 2004; 21:131-135)

ICU Care

solumedrol 60 mg Q6hrs

AutoPEEP

breath stacking from incomplete exhalation time

consider if the patient is hypotensive after initiation of mechanical ventilation

Must keep plat<35

test by lowering resp rate, occluding exhalation hose, and after patient finishes a breath, observe pressure

pt must first overcome autopeep in order to initiate a breath

NIPPV

IV Contrast

steroids do not help unless given 6-12 hours before study, give 3 doses Q6 of prednisone. Also give benadryl.

risk using low osmolality non-ionic contrast with asthmatic is same as regular contrast with non-asthmatic

Steroids in Asthma Exac

Inhaled budesonside: JAMA 281(22):2119, June 9, 1999. Relapse rate of 13% vs. 25%

Inhaled Steroids

Inhaled SteroidsTriamcinolone MDI 2 puffs bid-qid Rinse mouth after use $52/ cannister Beclomethasone MDI 2 puffs bid-qid Rinse mouth after use $52/ cannister Budesonide MDI 1-2 puffs bid Rinse mouth after use $108/cannister Fluticasone MDI, varying strengths 1-2 puffs bid Rinse mouth after use $44-$91/cannister

1.5 mg/kg (maximum, 45 mg) of nebulized dexamethasone (dexamethasone sodium phosphate, 10 mg/mL; Gensia) (Annals EM 26:485, 1995)

systematic review of inhaled steroids show benefit (Chest 2006;130:1301)

Stephen Streat:

1) Take the PEEP off (show me exactly what it is doing usefully for THIS patient). 2) Decrease the rate a lot (perhaps to 8) with a 20% inspiratory time. Modify the inspiratory flow pattern (take off the “inspiratory rise time” if you are using Servo300 or similar feature in other ventilator). 3) Titrate tidal volume to gas-trapping (expiratory flow graphic sometimes helpful, but the “ear to the tube” method works well for me) — and be much more relaxed about PIP during periods of high inspiratory resistance (caution when the bronchospasm breaks). See Dave Tuxens papers in the early 1990s — e.g. Am Rev Respir Dis. 1992 Nov;146(5 Pt 1):1136-42. You might find that with a rate of 8 and an expiratory time of ~ six seconds that you can get VE of around 6 litres with PIP of 40 or leven less and intrinsic PEEP of less than five) and much better alveolar ventilation as Vd/Vt is VERY different. 4) At five days she has probably compensated for the respiratory acidosis but we would sometimes give a little THAM acutely to get pH above about 7.05 (Do bronchodilators work better then?) 5) I bet she has had lots of mineralocorticoid (hydrodrocortisone) and salt water (count up all the saline bags and “diluents” over five days, test the depth of oedema with a thumb “the Bob Wright method” and then a) Stop all saline, b) diurese gently (lots of extra K+< maybe Mg++ too), to “dryness” c) give a salt-free feed, d) change to dexamethasone or at least prednisone if this has not already happened. 6) I usually don’t use muscle relaxants after a short time i.e. 12-24 hours of so — I see if the patient can be managed without them, usually with a combination of fentanyl and diazepam. I like to see the patient doing some expiratory assistance of their own, failing that I might give only a “softening dose” of relaxant (1-2 mg/hr of pancuronium — cheap, pressor and long acting — maybe less critical-illness polyneuropathy than vecuronium too). Let the patient help shift secretions by coughing (just a little). 7) We would not see this as “desperate straits” and would not use ketamine, inhalational agents etc in such a patient. Sit tight and avoid complications. 8) Despite all that is written about asthma in less severely ill patients, a trial of theophylline might be useful — it sometimes is. 9) I agree that we sometimes use IV adrenaline (epi to you Leo) instead of salbutamol (albuterol to you Leo) but both cause lactic acidosis, hypokalaemia, hyperglycaemia and perhaps adrenaline gives you some alpha action which might protect against the theophylline+IPPV hypotension. 10) 1:1 nursing is good — old nurses are best — ones who are old enough to have remembered ventilating these patients breath to breath on a Bird MkVII are to be preferred most .. ;-) S

Mike Darwin:

Also, is she on a leukotriene inhibitor? If not, you should strongly consider adding this to her Tx regimen. Bronchospasm is asthma is strongly leukotriene driven and long lasting bronchospasm is almost exclusively leukotriene mediated.

Ketamine

Review of Ketamine in Status Asthmaticus (Indian J Crit Care Med 2013;7(3):154)