Background: Despite concerns over their side effects, short-acting beta-2 agonists are still used in high doses in prehospital care internationally to treat asthma exacerbations. This systematic review set out to identify the physiological effects associated with this treatment and determine their potential impact on the patient's presenting or underlying conditions. Methods: A systematic search of literature published from 2010 to 2020 focusing on asthmatic patients receiving nebulised beta-2 agonists during an acute exacerbation was undertaken and relevant articles reviewed. Findings: Eight out of 897 studies met the inclusion criteria. While the studies were heterogeneous with a range of outcome measures, synthesis showed evidence of bronchodilator action throughout, with reductions in potassium levels and cardiovascular changes reported in several studies. Conclusions: Therapeutic effects demonstrated within the data support the use of nebulised beta-2 agonists in these patients and, while adverse effects are frequently seen in the cardiovascular and endocrine systems, their impact on the patient's overall condition remains unclear.