Use of incentive spirometry to prevent acute chest syndrome (ACS) in patients with sickle cell disease (SCD): a systematic review

Abstract

Sickle cell disease (SCD) is a genetic hematological disorder that causes the production of sickle-shaped red blood cells. These abnormal cells reduce the oxygen-carrying ability around the body and obstruct blood flow, potentially resulting in devastating complications such as acute chest syndrome (ACS). The objective of this systematic review is to assess whether incentive spirometry is effective in reducing the incidence of ACS in patients with SCD. This review searched databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) up to August 17, 2025. Randomized controlled trials (RCTs) that used incentive spirometry in patients with SCD were included in the review. Inclusion criteria for this review include patients diagnosed with SCD who have received incentive spirometry, with outcomes compared against standard prevention for ACS or other alternative interventions aimed at preventing or managing lung pathology. Studies must report on at least one of the following outcomes: incidence of ACS, pulmonary function, hospital stay duration, hospitalization rates, or adverse effects. This study found that three RCTs (29 patients, 38 patients, and 20 patients with a total of 124 hospitalizations) were included in this review. Two studies compared incentive spirometry to standard care, while only one compared incentive spirometry to positive expiratory pressure (PEP). A meta-analysis was conducted between two studies, with one trial suggesting that incentive spirometry successfully reduced the incidence of ACS and the other trial suggesting that it could not successfully reduce it. A meta-analysis of both studies found that incentive spirometry did not successfully reduce the incidence of ACS in patients with SCD (RR=0.51; 95% CI (0.21, 1.33)). The quality of this evidence was very low, due to the wide confidence interval, high risk of bias, and substantial heterogeneity. This review concluded that incentive spirometry could not successfully reduce the incidence of ACS in patients with SCD. Limitations of the studies used included small sample sizes and heterogeneity between study populations (i.e., children vs. adults). Therefore, further research is required to assess this, including larger, well-designed RCTs to be conducted focusing on core outcome sets (COS).