Chronic inflammation of your patient’s bronchi. Their bronchi are hypersensitive to environmental or intrinsic stimuli, leading to reversible episodes of bronchial constriction and mucosal edema.
Your patient will report:
- Chest tightness
- Chest pain
You will ask about:
- Comorbid diseases – you do not want to overlook another etiology to your patient’s symptoms (COPD, CHF, pneumonia)
- Inhaler use, especially recent increase in PRN inhalers
- History of asthma related admissions (especially in the last month or twice or more last year)
- History of symptoms worsening at night
- History of asthma related ICU admissions
- History of asthma related intubation
Remember: “a lack or risk factors does not necessarily confer a lack of risk”1
You will see and hear2
- Prolonged expiratory phase
- Limited or absent air movement on auscultation
- Increased work of breathing: retractions, accessory respiratory muscle use
- Altered mental status
Does my patient need any tests?
Peak expiratory flow/spirometry – obtain before and after treatment. Limited by selected patient’s inability to appropriately perform the test. Consider using this Youtube video to teach your patient how to properly perform the test. Data suggest that up to 83% of the total increase in peak flow occurs after the first treatment, so the utility of serial measurements might be limited.1,3 It should not be used in isolation as a disposition decision making tool.
Labs – only indicated if you have a concern for an alternative diagnosis. If your patient is on diuretics or has renal disease, check a BMP to assess for patient’s potassium, magnesium and phosphate levels, as beta agonists can decrease these.4
ABG – please do not violate your patient’s radial artery. Metabolic acidosis on a blood gas has been described as an indicator of impending arrest4, however, this can be assessed by getting a venous blood gas. Hypoxemia and hypercarbia on the ABG indicate a severe status asthmaticus, but again, a venous gas will suffice.5 The ABG can be normal in patients with impending respiratory arrest. Your clinical judgment is the best indicator of your patient’s need for therapy and intubation.
ECG – not routinely indicated, unless you are concerned about an alternative diagnosis. If obtained it might show signs of pulmonary disease, including signs of right atrial enlargement, right axis deviation, right bundle branch block, rhythm abnormalities or non-specific ST and T-wave abnormalities. The abnormalities are reversible.6
Chest radiograph – not routinely indicated, unless you have a concern for an alternative diagnosis or underlying pneumonia or pneumothorax.1 In a study of patients that were admitted with asthma 34% were found to have a abnormality on initial chest X-ray, of which 40% lead to a change in clinical management.7 The abnormalities included hyperinflation, focal infiltrates, increased interstitial markings and pneumothorax.
Is there a cure, doc?
Beta agonists – short acting beta agonists are the mainstay of treatment for your asthmatic patient in the emergency department. Use racemic albuterol, as multiple studies have not shown any benefit to the use of levalbuterol and it is more expensive.1 Long acting beta agonists have no role in the emergency department, and have even been linked to asthma related deaths.8
- Intermittent nebulizer: 2.5 – 5mg every 20 minutes up to 3 doses, followed by 2.5-10mg every 1-4 hours as needed
- Continuous nebulizer: 10-15 mg/hour
- MDI: 4-8 puffs every 20 minutes up to 4 hours, then space to every 1-4 hours
Cholinergics – efficacy as a solitary agent is inferior to use of albuterol, however, if used in combination with albuterol leads to improved peak expiratory flow and decreased hospitalization rates. Use 1-3 doses initially, no data to support use beyond the first 3 doses.10
Ipratropium bromide dosing:9
- Nebulizer (0.5mg/2.5mL or 0.2mg/mL): 2.5 mL, give 3 doses, may repeat every 6 hours (limited data to support this)
- MDI (18mcg/puff): 8 puffs every 20 minutes, repeat as needed (limited data to support this beyond the first 3 doses)
Intermittent vs. continuous – use continuous nebulizer treatments if your patient is suffering from a moderate or severe attack.11 Continuous nebulizers can reduces the hospitalization rate in some patients compared to intermittent treatments. There is no data on the use of continuous nebulizer in mild attacks.
MDI vs. nebulizers – there is no data suggesting nebulizers are superior to the use of MDI’s.12 MDIs are cheaper and require fewer personnel. It is also a great way to assess if you’re patient is capable of correctly administering MDI treatment doses, and educate them if necessary.
Corticosteroids – get steroids on board early. Administrating steroids in the first hour has shown to significantly reduce admission rates.13 There is no clear evidence that inhaled steroids alone or in combination with systemic steroids have any added benefit in the early treatment of your asthmatic patient.14 Steroids should be continued for 3-10 days after the first early dose, as it helps prevent bounce backs and late hospitalization rates.15 There is no clear data on exact duration and dosage of the short course of steroids. Five days of 40-60mg prednisone per day is most commonly prescribed. Intramuscular depo administration of steroids can be considered, Several studies have shown that one shot of intramuscular steroids has similar relapse rates compared to a 5 -7 days of oral steroids.16,17 You can use 12mg of bethamethasone or 40mg of triamcinolon i.m.
Magnesium – give magnesium early if your patient is suffering from a severe asthma attack, as it reduces admission rates in this patient population.18 Give 2 gm i.v. over 20 minutes. Data is limited, but magnesium has relatively few side effects. There is minimal evidence for administering magnesium if your patient is having a mild to moderate attack.
Antibiotics – only indicated if you have a high suspicion for bacterial illness.
Epinephrine – intramuscular or subcutaneous epinephrine may be considered as an adjunct if your patient has a severe asthma attack and you are concerned about the delivery of nebulized medication due to air-flow obstruction. However, keep in mind that if your patient has that much difficulty moving air intubation should be considered, and there is limited data that epinephrine helps prevent intubation. Mostly used in the peri-intubation setting.
Intubation and ventilation – the decision to intubate your asthmatic patient is not easy, as complications are prevalent and mortality is high. The decision is mostly made by your clinical judgment.1 Objective absolute indications include respiratory arrest or coma; relative indications include worsening hypercapnea, exhaustion and altered mental status. For an excellent discussion on ventilator management of your asthmatic patient please see the ‘EMCrit Lecture – Dominating the Vent: Part II’. If your patient is alert enough, a trial of NIPPV could be attempted. There are no large trials to support the use of NIPPV in asthmatic patients, but small trials suggest improvement in FEV1 measurements at 1 hour and decrease in hospitalization rate.19
At this time there is insufficient data to support the use of theophyline, aminiphylline, heliox or ketamine in the acute care setting.1
Treatment tips & tricks:
- When hooking up your patient for nebs, set the gas flow rate at 6-8 L/min
- Use a spacer when using MDI, even in adults
- Albuterol can be mixed with ipratropium into same solution. When using premixed solution dose: 3mL nebulizer solution every 20 minutes for 3 doses, then as needed or when using an MDI 8 puffs every 20 minutes as needed up to 3 hours.
Can’t I just go home, doc?
Disposition is largely based on how your patient looks, how your patient responds to treatment, and if your patient has adequate, readily available outpatient follow up.1 Traditionally it has been proposed that the discharge goal for asthmatic patient was a return to 70% of predicted peak flow spirometry, but as stated above, peak expiratory flow measurements are limited by patient’s ability to perform the test. Therefore, disposition still largely depends on your clinical impression of your patient. Consider a walking pulse ox if your patient still don’t look right
Ready? Dive, my friend!
- Life in the Fastlane – EBM Acute Asthma
- The NNT – Nebulized Ipratropium Given During an Asthma Attack
- The NNT – Systemic steroids given during an asthma attack
- The NNT – Intravenous Magnesium Sulfate Given During an Asthma Attack
- EM:RAP Mini Journal Club – Asthma Therapies: What Really Works!
- EMCrit Podcast 15 – the Severe Asthmatic
- PulmCCM – Beta-blockers: Safe (and Effective?) for Most Patients with Asthma, COPD
- Academic Life in Emergency Medicine – Lactic Acidosis and Beta Agonist Therapy in Asthma
- EMCrit Lecture – Dominating the Vent: Part II
- Emergency Medicine Literature of Note – Enoximone Miracle for Asthma: Science? Advertising? Both?
8. Ducharme FM, Ni Chroinin M, Greenstone I, Lasserson TJ. Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma. Cochrane Database Syst Rev. 2010 Apr 14;(4):CD005533.
9. National Heart Lung and Blood Institute. National Asthma Education Program. Expert Panel on the Management of Asthma, United States Department of Health and Human Services. National Institutes of Health (U.S.). Expert Panel report 3 guidelines for the diagnosis and management of asthma: full report. NIH publication No. 07-4051. Rev. June 2002, Aug. 2007. ed. Bethesda, MD.: U.S. Dept. of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute; 2007.
10. Rodrigo GJ, Rodrigo C. First-line therapy for adult patients with acute asthma receiving a multiple-dose protocol of ipratropium bromide plus albuterol in the emergency department. Am J Respir Crit Care Med. 2000;161(6):1862-1868.
14. Edmonds ML, Milan SJ, Camargo CA Jr, Pollack CV, Rowe BH. Early use of inhaled corticosteroids in the emergency department treatment of acute asthma. Cochrane Database Syst Rev. 2012 Dec 12;12:CD002308. doi: 10.1002/14651858.CD002308.pub2.
16. Schuckman H, DeJulius DP, Blanda M, Gerson LW, DeJulius AJ, Rajaratnam M. Comparison of intramuscular triamcinolone and oral prednisone in the outpatient treatment of acute asthma: a randomized controlled trial. Ann Emerg Med. 1998 Mar;31(3):333-8.
17. Chan JS, Cowie RL, Lazarenko GC, Little C, Scott S, Ford GT. Comparison of intramuscular betamethasone and oral prednisone in the prevention of relapse of acute asthma. Can Respir J. 2001 May-Jun;8(3):147-52.
Written by: Maite Huis in ‘t Veld, M.D. | Peer reviewed by: Haney Mallemat, M.D. | August 27th, 2014