Neutrophil To Lymphocyte Ratio - Association With Severity Parameters in Acute Asthma Exacerbation in Children

Background: Asthma, the most common chronic respiratory disease in children is characterized by chronic airway inflammation and hyperresponsiveness. Increased neutrophil-to-lymphocyte ratio (NLR) in peripheral blood count is a marker of chronic inflammation. We aimed to assess the utility of NLR in evaluating the course of acute asthma exacerbation among children admitted to the emergency department (ED).

Methods: This retrospective study includes children aged 2-18 years, that were referred for asthma exacerbation to the ED in Soroka University Medical Center. We examined the correlation of the NLR with clinical severity parameters, including oxygen saturation, respiratory rate, hospitalization rate, length of stay, intensive care unit admissions, need for oxygen support, and anti-asthmatic medications. The NLR was calculated from the blood count drawn at the ED.

Results: 103 children with acute asthma exacerbation were included. These were divided into two groups according to the median NLR (median=3.73, range 0.37-17.24). Prior steroid use rates were similar in both groups. Severity parameters were significantly higher in the high NLR group (n=52), compared with the low NLR group (n=51): mean oxygen saturation (93.4% vs 97%, p <0.001), mean heart rate (138 vs. 121.5 bpm, p=0.02) and respiratory rate at presentation (40.7 vs. 33.2, p=0.006). The hospitalization rate was 2.1 times higher in the high NLR group compared with low NLR (73.1% vs. 35.3%, p<0.001).

Conclusion: Higher NLR is associated with severe clinical course in children with acute asthma exacerbation. NLR is a simple low-cost measure that can assist in the ED assessment of pediatric asthma.