Asthma in the intensive care unit: A review of patient characteristics and outcomes

Abstract

Background. Most asthma-related deaths occur in low- and middle-income countries, and South Africa (SA) is ranked fifth in global asthma mortality. Little is known about the characteristics and outcome of asthma patients requiring intensive care unit (ICU) admission in SA. Objectives. To identify and characterise patients with acute severe asthma admitted to the respiratory ICU at Groote Schuur Hospital, Cape Town, SA, in order to evaluate outcomes and identify predictors of poor outcomes in those admitted. Methods. We performed a retrospective descriptive study of patients with severe asthma admitted to the respiratory ICU at Groote Schuur Hospital between 1 January 2014 and 31 December 2019. Results. One hundred and three patients (110 admission episodes) were identified with an acute asthma exacerbation requiring ICU admission; all were mechanically ventilated. There was a female preponderance (53.6%; n=59/110), with a median (range) age overall of 33 (13 - 84) years. Of all admissions, 40 (36.4%) were current tobacco smokers and 16 (14.5%) patients with a history of substance abuse. Two thirds (60.0%; n=66/110) of the patients were using an inhaled corticosteroid (ICS). No predictors of mortality were evident in multivariate modelling, although those who died were older, and had higher Acute Physiology and Chronic Health Evaluation (APACHE II) scores and longer duration of admission. Only 59 of the surviving 96 individual patients (61.5%) attended a specialist pulmonology clinic after discharge. Conclusion. Among patients admitted to the respiratory ICU at Groote Schuur Hospital for asthma exacerbations, there was a high prevalence of smokers and poor coverage with inhaled ICSs. Although mortality was low compared with general ICU mortality, more needs to be done to prevent acute severe asthma exacerbations.