Nebulized 3% Hypertonic Saline Versus Normal Saline in Managing Children With Acute Bronchiolitis: A Randomized Controlled Trial

This randomized controlled trial was conducted at A-Ramadi Teaching Hospital for Maternity and Children on patients admitted with acute bronchiolitis. The study covered a duration of 6 months. The study was approved by the Ethical Approval Committee of the University of Anbar. Informed consent was obtained from each parent.

The severity of bronchiolitis was assessed based on the absence (score = 0) or presence (score = 1) of the following parameters: tachycardia, wheezing, use of accessory muscles, low oxygen saturation (SpO₂ < 95%), and feeding difficulties. The total score, therefore, ranged from 0 to 5. Severity was subsequently classified into three categories: Mild (0-1), patients typically discharged home without the need for hospitalization; Moderate (2-3), patients admitted to the general pediatric ward for closer observation and supportive care; and Severe (4-5), patients requiring admission to the PICU due to significant respiratory compromise, such as oxygen saturation < 90%, intercostal recession, and wheezing requiring respiratory support [15].

All patients aged 0-24 months with a clinical diagnosis of bronchiolitis, defined by signs of acute respiratory distress, chest radiographic findings consistent with bronchiolitis, and a bronchiolitis severity score of (2-3), whose parents or guardians provided informed consent were enrolled in the study. Exclusion criteria were: severely ill infants requiring mechanical ventilation; age greater than 2 years; presence of chronic illnesses such as chronic renal disease, congenital heart disease, or neuromuscular disorders; immunocompromised status (including malnutrition or chronic corticosteroid use); diagnosis of asthma; prior use of corticosteroids or bronchodilators; and refusal of caregivers to participate in the trial.

We calculate the required sample size according to the mean LOS of 3 days from a previous study [5] and aimed to detect a clinically meaningful 25% reduction (~0.75 days), with a standard deviation of 1.92 days, 90% power, and a two-sided alpha of 0.05. Using the two-sample t-test formula for comparing means, this resulted in approximately 139 patients per group, which was increased to 150 per group to account for potential dropouts.

Eligible patients with moderate bronchiolitis who met the inclusion criteria were randomly assigned in a 1:1 ratio to either the hypertonic saline (3%) group or the normal saline (0.9%) group. Randomization was performed using a computer-generated random number sequence prepared by an independent statistician not involved in patient recruitment or treatment. Allocation concealment was ensured through the use of sequentially numbered, opaque, sealed envelopes, which were opened only after patient enrollment and completion of baseline assessments.

Due to the physical characteristics of the solutions, blinding of the nursing staff administering the nebulization was not feasible. However, the physicians responsible for clinical assessment and outcome evaluation were blinded to the treatment allocation to minimize observer bias. Parents or guardians were not informed of the specific solution used, and both groups received nebulization with an identical-appearing setup to maintain partial blinding at the patient and caregiver level.

Patients with moderate bronchiolitis were randomly allocated into two groups. The first group received 3% hypertonic saline as a diluent with salbutamol, whereas the second group received 0.9% normal saline as a diluent with salbutamol. Nebulization was administered via a compressed air-driven jet nebulizer four times daily by well-trained nursing staff under the supervision of on-call physicians. All other aspects of bronchiolitis management were provided similarly to both groups, including oxygen supplementation to maintain SpO₂ > 92%, airway suctioning, nebulization with salbutamol, and corticosteroid therapy. A follow-up flow chart was maintained for direct monitoring of each patient's clinical symptoms and signs of respiratory distress. Baseline clinical symptoms, vital signs, and respiratory severity scores were recorded for all participants at admission before initiation of the treatment protocol.

Data were analyzed using the Statistical Package for the Social Sciences software, version 29. Continuous variables were tested for normality using the Shapiro-Wilk test. Normally distributed data were expressed as mean±SD and compared between groups using the independent samples t-test. Non-normally distributed variables were presented as median and analyzed using the Mann-Whitney U test. Categorical variables were presented as frequencies and percentages, and differences between groups were assessed using the chi-square test or Fisher's exact test, as appropriate. The primary outcome was the difference in LOS between the two groups. Secondary outcomes included changes in respiratory severity score, oxygen saturation, and the proportion of patients progressing to severe disease.