Completing a rapid primary assessment and starting initial treatment
Assess severity of the acute asthma episode (moderate, severe or life-threatening) based on clinical observations and pulse oximetry measured while the person is breathing air, and administer a bronchodilator immediately.
- If oxygen therapy has already been started, it is not necessary to cease oxygen to measure pulse oximetry.
- Pregnancy is not a contraindication for bronchodilators in acute asthma.
- How this recommendation was developed
Based on clinical experience and expert opinion (informed by evidence, where available), with particular reference to the following source(s):
- Karpel et al. 19971
- Dhuper et al. 20112
- Cates et al. 20133
- Ferguson and Gidwani 20064
- Travers et al. 20125
- Salmeron et al. 19946
- Hodder et al. 20117
- O'Driscoll et al. 20088
- Global Initiative for Asthma (GINA) 20129
- British Thoracic Society (BTS), Scottish Intercollegiate Guidelines Network (SIGN) 200810
- Perrin et al. 201111
- Cyr et al. 199112
- Barry and O'Callaghan 199413
- Rau et al. 199614
- Ari et al. 201215
- Laube et al. 201116
Start oxygen therapy for all patients with severe or life-threatening acute asthma. Titrate oxygen saturation to target of 92–95% for adults and at least 95% for children.
- In adults, avoid over-oxygenation, because this increases the risk of hypercapnoea
- For children, consider whether humidification of oxygen is indicated
For patients with life-threatening asthma, arrange immediate transfer to the resuscitation area (or arrange transfer to acute service).
Figure. Initial management of life-threatening acute asthma in adults and children Please view and print this figure separately: https://www.asthmahandbook.org.au/figure/show/94
- How this recommendation was developed
Based on clinical experience and expert opinion (informed by evidence, where available)
Identify and manage anaphylaxis according to national guidelines or your organisation’s protocols. Give adrenaline if anaphylaxis is suspected or cannot be excluded.
Note: Consider anaphylaxis if patient presents with urticaria or angioedema as well as respiratory signs/symptoms, and in patients with a history of allergies
- Anaphylaxis guidelines and resources
- Adrenaline in acute asthma
Systemic adrenaline (intravenous in clinical settings with appropriately trained staff, or intramuscular) is indicated for patients with anaphylaxis and angioedema,9, 20 but current evidence does not support its routine use in the management of acute asthma in the absence of anaphylaxis.9
Nebulised adrenaline does not have a significant benefit over salbutamol or terbutaline in the management of moderate-to-severe acute asthma in adults and children.21Close
- Assessment of oxygen status in acute asthma
Hypoxia is the main cause of death that is due to acute asthma.7
Routine objective assessment of oxygen saturation at initial assessment of acute asthma is needed because clinical signs may not correlate with hypoxaemia.
Pulse oximetry is the internationally accepted method for routine assessment of oxygen status in patients with acute asthma.9
The risk of hypercapnoea increases when oxygen saturation falls below 92%.22
Pulse oximetry does not detect hypercapnoea, so blood gas analysis is necessary if hypercapnoea is suspected in patients with severe or life-threatening acute asthma.Close
- Oxygen therapy in acute asthma
Oxygen is a treatment for hypoxaemia, not breathlessness. Oxygen has not been shown to improve the sensation of breathlessness in non-hypoxaemic patients.8 When oxygen supplementation is used, pulse oximetry is necessary to monitor oxygen status and titrate to target.
The aim of titrated oxygen therapy in acute care is to achieve normal or near-normal oxygen saturation, except in patients who are at risk of hypercapnoeic respiratory failure,8 such as patients with overlapping asthma and COPD.
In adults with acute asthma, titrated oxygen therapy using pulse oximetry to maintain oxygen saturation at 93–95% while avoiding hyperoxaemia achieves better physiological outcomes than 100% oxygen at high flow rate (8 L/min).11 High-concentration and high-flow oxygen therapy cause a clinically significant increase in blood CO2 concentration in adults with acute asthma.11, 23
National guidelines for the management of acute exacerbations of COPD recommend that hypoxic patients should be given controlled oxygen therapy via nasal prongs at 0.5–2.0 L/minute or a venturi mask at 24% or 28%, with target oxygen saturation of over 90% (PaO2 >50 mmHg, or 6.7 kPa).24 Excessive oxygen administration should be avoided because it can worsen hypercapnoea.24
Drying of the upper airway is a potential complication of oxygen therapy in children,25, 26 which might contribute to bronchoconstriction.26 Humidified oxygen can be considered if necessary. Humidification is usually not needed for low flow oxygen (<4 L/minute in children or 2 L/minute in infants) for short term. Humidification may be considered if the oxygen is required for longer than 48 hours or if the nasal passages are becoming uncomfortable or dry.25
Guidance on oxygen delivery techniques and practical issues is available from Sydney Children's Hospital Network and The Royal Children's Hospital Melbourne.Close
- Karpel JP, Aldrich TK, Prezant DJ, et al. Emergency treatment of acute asthma with albuterol metered-dose inhaler plus holding chamber: how often should treatments be administered?. Chest. 1997; 112: 348-356. Available from: http://www.ncbi.nlm.nih.gov/pubmed/9266868
- Dhuper S, Chandra A, Ahmed A, et al. Efficacy and cost comparisons of bronchodilatator administration between metered dose inhalers with disposable spacers and nebulizers for acute asthma treatment. J Emerg Med. 2011; 40: 247-55. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19081697
- Cates CJ, Welsh EJ, Rowe BH. Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma. Cochrane Database Syst Rev. 2013; 9: Cd000052. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24037768
- Ferguson C, Gidwani S. Delivery of bronchodilators in acute asthma in children. Emerg Med J. 2006; 23: 471-472. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2564350/
- Travers AH, Milan SJ, Jones AP, et al. Addition of intravenous beta(2)-agonists to inhaled beta(2)-agonists for acute asthma. Cochrane Database Syst Rev. 2012; 12: CD010179. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010179/full
- Salmeron S, Brochard L, Mal H, et al. Nebulized versus intravenous albuterol in hypercapnic acute asthma. A multicenter, double-blind, randomized study. Am J Respir Crit Care Med. 1994; 149: 1466-1470. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8004299
- Hodder R, Lougheed MD, Rowe BH, et al. Management of acute asthma in adults in the emergency department: nonventilatory management. CMAJ. 2010; 182: E55-67. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817338/
- O’Driscoll BR, Howard LS, Davison AG, British Thoracic Society (BTS) Emergency Oxygen Guideline Development Group. BTS guideline for emergency oxygen use in adult patients. Thorax. 2008; 63 (Suppl 6): vi1-vi68. Available from: http://thorax.bmj.com/content/63/Suppl_6/vi1.full
- Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA, 2012. Available from: http://www.ginasthma.org
- British Thoracic Society (BTS) Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the Management of Asthma. Quick Reference Guide. Revised May 2011. BTS, SIGN, Edinburgh, 2008.
- Perrin K, Wijesinghe M, Healy B, et al. Randomised controlled trial of high concentration versus titrated oxygen therapy in severe exacerbations of asthma. Thorax. 2011; 66: 937-41. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21597111
- Cyr TD, Graham SJ, Li KY, Levering EG. Low first-spray drug content in albuterol metered-dose inhalers. Pharm Res. 1991; 8: 658-660. Available from: http://link.springer.com/article/10.1023/A:1015825311750
- Barry PW, O'Callaghan C. Multiple actuations of salbutamol MDI into a spacer device reduce the amount of drug recovered in the respirable range. Eur Respir J. 1994; 7: 1707-1709. Available from: http://www.ncbi.nlm.nih.gov/pubmed/7995401
- Rau JL, Restrepo RD, Deshpande V. Inhalation of single vs multiple metered-dose bronchodilator actuations from reservoir devices : An in vitro study. Chest. 1996; 109: 969-974. Available from: http://www.ncbi.nlm.nih.gov/pubmed/8635379
- Ari A, Fink JB, Dhand R. Inhalation therapy in patients receiving mechanical ventilation: an update. J Aerosol Med Pulm Drug Deliv. 2012; 25: 319-32. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22856594
- Laube BL, Janssens HM, de Jongh FHC, et al. What the pulmonary specialist should know about the new inhalation therapies. Eur Respir J. 2011; 37: 1308-1417. Available from: http://erj.ersjournals.com/content/37/6/1308.full
- Brandao DC, Britto MC, Pessoa MF, et al. Heliox and forward-leaning posture improve the efficacy of nebulized bronchodilator in acute asthma: a randomized trial. Respir Care. 2011; 56: 947-52. Available from: http://rc.rcjournal.com/content/56/7/947.full
- Rodrigo G, Pollack C, Rodrigo C, Rowe BH. Heliox for nonintubated acute asthma patients. Cochrane Database Syst Rev. 2006; Issue 4: CD002884. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD002884.pub2/full
- Singhi S, Mathew JL, Torzillo P. What is the role of subcutaneous adrenaline in the management of acute asthma?. International Child Health Review Collaboration, 2006. Available from: http://www.ichrc.org/cough-or-difficult-breathing
- Australasian Society of Clinical Immunology and Allergy (ASCIA). Acute management of anaphylaxis guidelines. ASCIA, Sydney, 2013. Available from: http://www.allergy.org.au/health-professionals/papers/acute-management-of-anaphylaxis-guidelines
- Rodrigo GJ, Nannini LJ. Comparison between nebulized adrenaline and beta2 agonists for the treatment of acute asthma. A meta-analysis of randomized trials. Am J Emerg Med. 2006; 24: 217-22. Available from: http://www.ncbi.nlm.nih.gov/pubmed/16490653
- British Thoracic Society (BTS), Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the Management of Asthma. A national clinical guideline. BTS, SIGN, Edinburgh, 2012. Available from: https://www.brit-thoracic.org.uk/guidelines-and-quality-standards/asthma-guideline/
- Rodrigo GJ, Rodriquez Verde M, Peregalli V, Rodrigo C. Effects of short-term 28% and 100% oxygen on PaCO2 and peak expiratory flow rate in acute asthma: a randomized trial. Chest. 2003; 124: 1312-7. Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1081910
- Abramson MJ, Crockett AJ, Dabscheck E, et al. The COPD-X Plan: Australian and New Zealand guidelines for the management of chronic obstructive pulmonary disease. Version 2.34. The Australian Lung Foundation and The Thoracic Society of Australia and New Zealand, 2012. Available from: http://www.copdx.org.au/
- Sydney Children's Hospital. Oxygen therapy and delivery devices – SCH. Practice guideline. Guideline No: 0/C/13:7019-01:00. Sydney Children's Hospital Westmead, Sydney, 2013. Available from: http://www.chw.edu.au/about/policies/alphabetical.htm
- The Royal Children's Hospital of Melbourne, Oxygen Delivery. Clinical Guidelines (Nursing), The Royal Children's Hospital 2013. Available from: http://www.rch.org.au/rchcpg/hospitalclinicalguidelineindex/Oxygendelivery/