Exacerbations of bronchiectasis

Abstract

Bronchiectasis presents a significant challenge due to its rising prevalence, associated economic burden and clinical heterogeneity. This review synthesises contemporary understanding and literature of bronchiectasis exacerbations, addressing the transition from stable state to exacerbations, underlining the importance of early and precise recognition, rigorous severity assessment, prompt treatment, and prevention measures, as well as emphasising the need for strategies to assess and improve early and long-term patient outcomes. The review highlights the interplay between stable state phases and exacerbations in bronchiectasis, introducing the concept of "exogenous and endogenous changes in airways homeostasis" and the "adapted island model" with a particular focus on "frequent exacerbators", a group of patients associated with specific clinical characteristics and worse outcomes. The pathophysiology of exacerbations is explored through the lens of microbial and nonmicrobial triggers and the presence and the activity of comorbidities, elaborating on the impact of both exogenous insults, such as infections and pollution, and endogenous factors such as inflammatory endotypes. Finally, the review proposes a multidisciplinary approach to care, integrating advancements in precision medicine and biomarker research, paving the way for tailored treatments that challenge the traditional antibiotic paradigm.

FIGURE 1

Disease decline and exacerbations in the natural history of bronchiectasis. a) Trajectory of lung function over time in bronchiectasis. The decline in lung function is associated with the occurrence of both mild/moderate and severe exacerbations. b) Oscillation between stable states and exacerbations over time, the influence of triggers and the impact of protective factors and interventions on maintaining overall lung health and raising the threshold for exacerbations.

FIGURE 2

“Adapted island model” and the “vicious vortex/cycle” in bronchiectasis pathophysiology. This figure illustrates the dynamic homeostasis of lung inflammation, likened to an “island”, affected by both exogenous factors such as infections and pollution, and endogenous factors including underlying diseases and immune responses. One or more triggers may destabilise these interactions leading to exacerbations. These factors are also grouped according to the aspect of the vortex/island to which they predominantly relate. GERD: gastroesophageal reflux disease; P.: Pseudomonas.

FIGURE 3

Stepwise approach in the management of bronchiectasis exacerbation. Comprehensive management pathway for bronchiectasis. This figure delineates a structured approach to the clinical management of bronchiectasis, highlighting key steps from initial suspicion and confirmation to severity assessment, followed by targeted treatment strategies and culminating in preventative measures to mitigate future exacerbations. ACT: airway clearance technique; BEST: bronchiectasis exacerbation and symptom tool; CV: cardiovascular; i.v.: intravenous; OPAT: outpatient parenteral antibiotic therapy.