Infections are a common pediatric complaint worldwide, with most cases involving the upper and lower respiratory systems. Bronchiolitis is considered a common lower respiratory tract infection among children aged between 6 months and 2 years. Bronchiolitis is the inflammation and obstruction of the bronchioles, the smallest aspect within the respiratory tract [1,2]. Although it has multiple etiologies, it is mainly caused by a viral infection, almost exclusively by Respiratory Syncytial Virus (RSV), which is a major cause of morbidity and mortality among infants [2]. RSV is noted to be the cause of more than 3.3 million cases worldwide [3,4]. It is important to note that RSV is highly contagious, with viral shedding seen even after three weeks of infection [5]. Therefore, proper precautions must be taken to avoid the spread between infants in schools, communities, and neighborhoods.

Almost 2% of infants presenting to the emergency department are admitted to the hospital due to bronchiolitis, mainly in epidemic seasons such as winter [3]. Infants may present with a range of symptoms, including shortness of breath, wheezing, cough, or signs of respiratory distress, which may lead to the need for acute intervention such as mechanical ventilation secondary to respiratory failure [2]. Bronchiolitis is considered a clinical diagnosis, with a respiratory panel through a nasopharyngeal swab used when in doubt [5]. Management is usually supportive. Physicians tend to use pharmacological therapy such as nebulization therapy, steroids, and antibiotics [5].

Prophylactic therapy and use are of the utmost importance, especially for high-risk patients. These patients include infants with neuromuscular illness, preterm neonates, infants with congenital airway anomalies, and more [5-7]. Prophylactic therapy for any illness has a huge impact on decreasing morbidity, mortality, and overall chronic complications [5]. In terms of bronchiolitis, although no vaccine is available, the production of Palivizumab has created a shift in the prevention of bronchiolitis and its complications in general [5,6]. Approved by the Food and Drug Administration (FDA) in 1998, it is considered the main prophylactic agent for bronchiolitis caused by RSV in high-risk patients [6]. Palivizumab is a monoclonal antibody, usually administered as an intramuscular injection at a rate of once per month for five consecutive months within the age of 24 months [7]. The use of Palivizumab has been proven effective in decreasing admission rates within tertiary hospitals. In a study conducted in 2021, it was noted that the use of the monoclonal antibody reduced the rate of admissions in the pediatric population from 98 to 43 per 1000 [8]. Furthermore, a meta-analysis conducted in 2023 showed that Palivizumab has not only reduced admission rates but also decreased the use of supplemental oxygen and the admission rates to the pediatric intensive care unit [9]. To understand the cost-effectiveness of Palivizumab use, a study conducted in 2012 showed that its use has reduced costs on hospitals, leading to a more cost-effective approach to bronchiolitis management [10]. However, the cost-effectiveness of Palivizumab has been debated [11]. Therefore, this study aims to review the admission rates and severity of bronchiolitis among high-risk patients who received Palivizumab at King Hamad University Hospital between the years 2018 to 2022, to understand its impact on cost-effectiveness on the hospital.