Introduction
The coronavirus disease 19 (COVID 19) which spread worldwide during few years ago, caused great challenge in health, economy, social and environment (1). This mysterious virus represents with very heterogeneous organ involvements. The most prevalent presentations are fever, cough and anosmia (2). In spite of most early reports considered mild infection in children, gradually increasing concerns was developed about long-term complications of disease (3, 4). Early in 2020, there were several reports of a disease mimicking Kawasaki in children, which present with fever and muco-cutaneous as well as multi-organ involvement. Majority of patients with this new emerging syndrome, represent with cardiac involvement and require intensive care unit (ICU) admission (5). After that, many data were released about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children with more morbidity and mortality.
Autopsy examination in patients who dead due to COVID 19 has shown different grades of fibro proliferative procedures and diffuse alveolar injury. Therefore, it seems that COVID 19 survivors might be at risk for respiratory sequel and persistent impaired pulmonary function tests. According to expected pathophysiology, restrictive pattern is more probable. Available data has revealed that abnormal diffusing capacity for carbon monoxide (DLCO), which is relevant with severity of acute illness, is the most prevalent result in pulmonary function test (PFT) of post-acute patients. While ground grass opacities is most common in high-resolution computed tomography (HRCT) of them (6, 7). A recent meta-analysis has shown that 77% of infected patients with SARS-Cov2 had abnormal lung computed tomography (CT) in acute phase (2). Several studies reported persistent post-COVID 19 respiratory symptoms. In one study, 25-42% of patients reported moderate to severe dyspnea, 4-8 weeks after hospital discharge (8).
Because of continues growth and development of respiratory system in pediatrics especially during infancy and early childhood, they are more vulnerable to pulmonary sequel (9).
Pulmonary function test is one of methods, which can evaluate long-term pulmonary sequel in survived COVID 19 patients. This is safe, objective and more favorable than imaging. This tool is useful in assessment of degree of airway restriction and obstruction (9).
To the best of our knowledge, there is not any systematic review and meta-analysis regarding long-term respiratory outcome in pediatric population post-SARS-CoV-2 infection. Since future of pediatric survivors of COVID 19 is uncertain, we have conducted present systematic review and meta-analysis to summarize available evidence and define the gapes, which may initiate future studies.
Methods :