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Year : 2020  |  Volume : 34  |  Issue : 2  |  Page : 86-90

Comparison of 3% saline versus normal saline as a diluent for nebulization in hospitalized children with acute bronchiolitis: A randomized clinical trial

Department of Pediatrics, Regional Institute of Medical Sciences, Imphal, Manipur, India

Date of Submission19-Jun-2020
Date of Acceptance18-Nov-2020
Date of Web Publication25-Jan-2021

Correspondence Address:
Shyamsunder Chongtham
Department of Pediatrics, Regional Institute of Medical Sciences, Imphal - 795 004, Manipur
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jms.jms_43_20

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Context: Bronchiolitis, the most common lower respiratory tract infection among infants and young children, is managed with a few clinically beneficial interventions. Hypertonic saline (HS) nebulization is suggested in the treatment of bronchiolitis, resulting in clinical improvement.
Aim: The aim of the study was to compare the efficacy 3% HS versus 0.9% normal saline (NS) as nebulization diluent in children between 3 months and 2 years with acute bronchiolitis.
Materials and Methods: In this prospective randomized controlled study, 158 admitted children between 3 months and 2 years with acute bronchiolitis were assigned into two groups – 3% HS and NS. Outcome variables were improvement in clinical severity (CS) score and length of hospital stay (LOS). Descriptive statistics such as mean, median, standard deviation, and percentages were used. Chi-square and t-tests were used to determine associations. Data analysis was performed using SPSS IBM version 21.
Results: Baseline CS scores were similar – 3.98 ± 1.20 and 3.75 ± 1.06 for HS and NS groups (P = 0.209), respectively, but from the 2nd day of treatment, it decreased to 2.21 ± 1.10 for HS and 3.05 ± 1.17 for NS group (P ≤ 0.001), further reducing to 1.46 ± 0.63 for HS group and 2.01 ± 0.99 for NS group (P ≤ 0.001). Length of stay was also reduced: 4.98 ± 1.35 for the HS group compared to 5.84 ± 1.18 for the NS group (P ≤ 0.001).
Conclusion: Using 3% HS instead of NS as a diluent for nebulization decreases clinical symptoms acute bronchiolitis besides the length of hospital stay.

Keywords: Bronchiolitis, clinical score, hypertonic saline, nebulization

How to cite this article:
Hmar L, Brahmacharimayum S, Golmei N, Moirangthem M, Chongtham S. Comparison of 3% saline versus normal saline as a diluent for nebulization in hospitalized children with acute bronchiolitis: A randomized clinical trial. J Med Soc 2020;34:86-90

How to cite this URL:
Hmar L, Brahmacharimayum S, Golmei N, Moirangthem M, Chongtham S. Comparison of 3% saline versus normal saline as a diluent for nebulization in hospitalized children with acute bronchiolitis: A randomized clinical trial. J Med Soc [serial online] 2020 [cited 2022 Aug 7];34:86-90. Available from:

  Introduction Top

Bronchiolitis is recognized as a constellation of clinical symptoms and signs including a viral upper respiratory prodrome followed by increased respiratory effort and wheezing in children <2 years of age[1] and is the most common lower respiratory tract infection among infants in both developed and developing countries.[2] In India, outbreaks occur between September and March with an incidence of 76% in <1 year and 94% in <2 years.[3] The mortality rate is 0.5%–1.5% even in hospitalized patients, which may increase to 3%–4% for patients with underlying cardiac or pulmonary disease.[4]

Acute bronchiolitis is mostly caused by a respiratory syncytial virus (RSV), occurring in epidemics in winter months,[3],[5] though parainfluenza, adenovirus, rhinovirus, and mycoplasma may also contribute. Initially beginning with sneezing, rhinorrhea, decreased appetite, and moderate grade fever, respiratory distress ensues in a few days with tachypnea interfering with feeding. On examination, there is wheezing, prolonged expiration, fine rales, and rhonchi. With further aggravation nasal flaring, intercostal and subcostal retractions, hyperexpansion of the chest, restlessness, and peripheral cyanosis may ensue. The diagnosis is usually a clinical one, but the confirmation of RSV infection can be made by enzyme-linked immunofluorescence assay and fluorescent antibody techniques for viral genome detection by polymerase chain reaction or viral culture.[4],[5]

Many interventions are usually tried, for example, inhaled bronchodilators, steroids, anticholinergics, epinephrine, antibiotics, surfactant, and chest physiotherapy, but with unpredictable responses.[1],[6],[7] Moreover, bronchiolitis patients not only risk increased morbidity or mortality but also incur considerable expenses.

Some studies have suggested that hypertonic saline (HS) nebulization may be safe and useful in making secretions less viscous and promoting their excretion, thereby resulting in clinical improvement.[8],[9],[10] Theoretical mechanisms of action for HS include inducing an osmotic flow of water into the mucus layer, thus rehydrating the airway surface liquid and improving mucociliary clearance, as well as reducing airway edema by absorbing water from the mucosa and submucosa.[11]

As the acceptable treatment modalities are imprecise, this study was planned to determine the clinical profile of acute bronchiolitis and compare the efficacy of cheap and readily available 3% HS versus 0.9% normal saline (NS) as a diluent for nebulization in the management of acute bronchiolitis in children aged between 3 months to 2 years.

  Materials and Methods Top

Designed as a randomized clinical trial, children aged 3 months to 2 years of age admitted with features of acute bronchiolitis[1] in the Pediatric Ward of RIMS, Imphal, Manipur, during a period of 2 years from September 2016 to August 2018 were included in the study. Children diagnosed with bacterial or aspiration pneumonia, previous wheezing episodes, oxygen saturation <92% in room air, cyanosis, obtunded consciousness, progressive respiratory failure requiring mechanical ventilation, foreign body inhalation, cardiac disease,congenital malformations and parents refusing consent were excluded from the study.

Sample size

Using 80% power and 5% error using reference from a previous study[12] where κ = nA/nB is 1, which is the matching ratio for both the groups, σ is the standard deviation, and α = 1.96, the calculated sample for each group was 79, i.e., 158 children aged between 3 months and 2 years.

Sampling procedure

Recruited patients were assigned randomly into two groups using a standard randomization table.

Outcome variables

(1) Improvement in respiratory distress-clinical severity (CS) score (2) length of hospital stay (LOS).

Survey tools and instruments

Recruited patients were randomly assigned to 3% HS group patients receiving salbutamol inhalation in 3 mL of 3% saline solution and NS group patients received inhalation of salbutamol in 3 mL of 0.9% saline solution. Nebulization was done using Apex Eco-Plus nebulizer made by Apex Medical Corp, France. All patients were enrolled within 24 h of hospital admission, examined, and every day, at treatment time. Patients in each group received four treatments for every day of hospital stay delivered 6 hourly interval, until fit for discharge. Additional inhalations as needed were recorded and calculated as add-on therapy. The clinical parameters were measured and recorded using a CS score described by Wang et al.[13] [Table 1].
Table 1: Clinical severity score[13]

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Discharge criteria were the absence of fever and respiratory distress, breathing room air comfortably with saturation >96%, and tolerating oral feeds. Patients who showed signs of deterioration/severe disease were planned to be left out of the study. Antibiotics were used in the presence of fever, leukocytosis, and chest X-ray infiltrations. Ethical approval was obtained from the Research Ethics Board, RIMS, Imphal, before the study commencement. Informed consent for each enrolled patient was obtained from the parents/legal guardians. Confidentiality and privacy were strictly maintained.

Statistical analysis

Data collected after checking for completeness and consistency were entered in IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: BM Corp for Windows and summarized using descriptive statistics such as percentages and standard deviation. Chi-square and t-tests were applied to test the associations. P < 0.05 was taken as significant.

  Results Top

In the present study, the maximum number of cases occurred in the >6–12 months age group – 46 (58.2%) for HS group and 36 (45.6%) for NS group, followed by 3–6 months' group – 20 (25.3%) and 32 (40.5%) cases, respectively. The mean age (months) for the HS group was 10.02 ± 5.45 and for the NS group, it was 8.45 ± 4.88 [Table 2]. There was a predominance of male patients with 53.2% and 61% in both the HS group and NS group, respectively. Family history of atopy was found in 2 (2.5%) of the HS group and 5 (6.3%) patients in the NS group (P = 0.246). Twenty-four (30.4%) patients in HS and 23 (29.1%) in NS group had smokers in the family (P = 0.862).
Table 2: Characteristics of the study participants

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In our study, using 3% HS as a diluent for nebulization with salbutamol produced a significant reduction in the CS Scores as compared to treatment with NS as a diluent. The baseline CS scores in the HS and NS groups were 3.98 ± 1.20 and 3.75 ± 1.06, respectively (P = 0.209) [Table 3] but dropped to 2.21 ± 1.10 (HS) and 3.05 ± 1.17 (NS) groups after treatment on day 2 of admission (P < 0.001). The fall in CS Score was more pronounced in the HS group, even on the 3rd day of admission (P < 0.001) [Table 3] and [Figure 1].
Table 3: Clinical severity scores for the study group

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Figure 1: Clinical severity scores at different days of admission

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The duration of fever (days) was 3.59 ± 1.77 and 3.65 ± 2.24 for the HS and NS groups (P = 0.844), respectively [Table 4]. Cough and difficulty of breathing duration were also not much different between the two groups (P > 0.05). However, the mean length of stay was substantially lower in the HS group with 4.98 ± 1.35 days than the NS group with 5.84 ± 1.18 days (P < 0.001). The patient discharge rate was also faster in the HS group when compared with the NS group [Figure 2].
Table 4: Characteristics of patients in the hypertonic saline and normal saline group

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Figure 2: Number of patients remaining in hospital until discharge

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  Discussion Top

Bronchiolitis affects mostly infants and young children, usually below 2 years and is more common in boys.[1],[12] In the present study, the mean age for the HS and NS groups was 10.02 ± 5.45 and 8.45 ± 4.88 months, respectively, with a preponderance of patients belonging to 6–12 months – 46 (58.2%) in the HS group and 36 (45.6%) for NS group [Table 2]. Majority were males, comprising 53.2% in the HS group and 60.8% in the NS group. In other studies,[14],[15] a maximum number of patients were also males but younger (1–6 months age) for both HS and NS groups. Although the family history of exposure to smokers and atopy were observed in our study, they were insignificant [Table 1]. Wu et al.[15] had observed that lesser participants, 13.5% (HS group) and 9.1% (NS group), were exposed to tobacco smoke; 8.1% of HS group and 4.1% of NS group had atopy.

The CS baseline scores (CS score) taken at the time of admission or <12 h (baseline CS score) were similar and comparable [Table 3]. However, on the 2nd day, the CS score for the HS group was 2.21 ± 1.10 and 3.05 ± 1.17 for the NS group (P < 0.001), implying a better CS score improvement among the HS group than the NS group from the 2nd day itself. On the 3rd day, the CS score for the HS group was 1.46 ± 0.63 and 2.01 ± 0.99 for the NS group. Here also, there was an improvement in the CS score for both the groups but more in the HS group. Earlier, Sarrell et al.[8] had reported 3% saline to be effective in reducing disease symptoms and severity when co-administered with a bronchodilator in ambulatory bronchiolitis patients. Studies conducted in hospitalized bronchiolitis patients had also described better improvement in CS scores with HS, but the magnitude of improvement varied on different treatment days ranging from 15.7% on day 1 to 29.4% on day 3 in HS group.[9],[10],[16] Mandelberg et al.[9] had found that in nonasthmatic, nonseverely ill infants hospitalized with viral bronchiolitis, using 3% saline solution with 1.5 mg epinephrine decreased the hospitalization stay by 25% (from 4 ± 1.9 days) as compared to 0.9% saline solution with 1.5 mg epinephrine [3 ± 1.2 days (P < 0.05)]. In another study by Luo et al.,[16] the CS scores decreased more significantly in HS group than in NS group on each day within 96 h after enrolment. In their Cochrane review, Zhang et al.[17] suggested that nebulized 3% saline may significantly reduce the length of hospital stay and improve the CS score in infants with acute viral bronchiolitis. In our study, the patients in the HS group were found to be fit for discharge and met the protocol-defined discharge criteria quicker than the NS group, as seen in [Figure 1]. The rate of discharge was comparatively faster with fewer patients remaining in the HS group each day till the 7th day of hospital stay [Figure 2].

Length of stay (LOS), in our study, was defined as the time between study entry (within 12 h of hospital admission) and the time at which the patient reached the protocol defined discharge criteria. The mean length of stay in the present study was 4.98 ± 1.35 days for the HS group and 5.84 ± 1.18 days for the NS group (P < 0.001), which was approximately 1 day shorter in the HS group than the NS group [Table 4]. Kuzik et al.[10] had also observed that HS group infants had clinically relevant 26% reduction in LOS to 2.6 ± 1.9 days, compared with 3.5 ± 2.9 days for NS group infants (P = 0.05). Similarly, Luo et al.[16] found that LOS decreased from 6.4 ± 1.4 days in the NS group patients to 4.8 ± 1.2 days in the HS group (P < 0.01).

However, other authors had averred that nebulized 3% saline was not superior to 0.9% saline in infants with clinically diagnosed acute bronchiolitis[14] and treatment with nebulized 3% HS compared to NS had no difference in LOS or 7-day readmission rates.[18] Mahesh Kumar et al.[19] had also reported that though aerosolized 3% saline was safe and prevented worsening of clinical symptoms, it was not superior to NS in reducing the CS and length of hospital stay in hospitalized children with moderate acute bronchiolitis. In agreement with Wu et al.,[15] who stated the beneficial effects of 3% HS in combination with a bronchodilator, we had also observed that HS group patients had better improvement in CS scores and reduced length of stay as compared to the NS group. Moreover, we did not notice any adverse effects or worsening of symptoms. The diagnosis of bronchiolitis in our study was based on clinical considerations as virological diagnostic facilities were not available. Ours was a preliminary study in our region comparing 3% HS versus NS as diluents to salbutamol and whether our findings may be extrapolated for wider use cannot be emphasized at this juncture due to less number of patients and its single centric nature. Nonetheless, taking into account the encouraging findings of this study, nebulization with 3% HS in combination with a bronchodilator may offer better outcomes in hospitalized bronchiolitis patients.

  Conclusion Top

In hospitalized infants with acute bronchiolitis, nebulization of salbutamol with 3% saline as a diluent in comparison to normal saline appears to be safe and beneficial as evidenced by the decreased clinical symptoms from the second day of hospitalization besides reducing the length of hospital stay. However, the optimal dosage and treatment regimen for usage of 3% saline in nebulization need to be studied further.

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Conflicts of interest

There are no conflicts of interest.

  References Top

American Academy of Pediatrics Subcommittee on diagnosis and management of bronchiolitis. Diagnosis Manag Bronchiol Pediat 2006;118:1774-93.  Back to cited text no. 1
Klassen TP. Recent advances in the treatment of bronchiolitis and laryngitis. Pediatr Clin North Am 1997;44:249-61.  Back to cited text no. 2
Cherian T, Simoes EA, Steinhoff MC, Chitra K, John M, Raghupathy P, et al. Bronchiolitis in tropical south India. Am J Dis Child 1990;144:1026-30.  Back to cited text no. 3
Dennis MM. Bronchiolitis. Arch Dis Child Educ Pract 2005;90:81-6.  Back to cited text no. 4
Coates BM, Camarda LE, Goodman DM. Wheezing, bronchiolitis and bronchitis. In: Kleigman RM, Stanton BF, St Geme III WJ, Schor NF, editors. Nelson Textbook of Pediatrics. 1st ed.. South Asia: Reed Elsevier India; 2016. p. 2044-8.  Back to cited text no. 5
Nagakumar P, Doull I. Current therapy for bronchiolitis. Arch Dis Child 2012;97:827-30.  Back to cited text no. 6
Eber E. Treatment of acute viral bronchiolitis. Open Microbiol J 2011;5:159-64.  Back to cited text no. 7
Sarrell EM, Tal G, Witzling M, Someck E, Houri S, Cohen HA, et al. Nebulized 3% hypertonic saline solution treatment in ambulatory children with viral bronchiolitis decreases symptoms. Chest 2002;122:2015-20.  Back to cited text no. 8
Mandelberg A, Amirav I. Hypertonic saline or high volume normal saline for viral bronchiolitis: Mechanisms and rationale. Pediatr Pulmonol 2010;45:36-40.  Back to cited text no. 9
Kuzik BA, Al-Qadhi SA, Kent S, Flavin MP, Hopman W, Hotte S, et al. Nebulized hypertonic saline in the treatment of viral bronchiolitis in infants. J Pediatr 2007;151:266-70.  Back to cited text no. 10
Hall CB, Weinberg GA, Iwane MK, Blumkin AK, Edwards KM, Staat MA, et al. The burden of respiratory syncytial virus infection in young children. N Engl J Med 2009;360:588-98.  Back to cited text no. 11
Malik G, Singh A, Singh K, Pannu MS, Singh P, Banga S, et al. A comparative study to assess the effects of nebulized 3% hypertonic saline, 0.9% normal saline and salbutamol in management of acute bronchiolitis among Indian children. J Evol Med Dent Sci 2015;4:3662-8.  Back to cited text no. 12
Wang EE, Milner RA, Navas L, Maj H. Observer agreement for respiratory signs and oximetry in infant's hospitalized with lower respiratory infections. Am Rev Respir Dis 1992;145:106-9.  Back to cited text no. 13
Sharma BS, Gupta MK, Rafik SP. Hypertonic (3%) saline vs 0.93% saline nebulization for acute viral bronchiolitis: A randomized controlled trial. Indian Pediatr 2013;50:743-7.  Back to cited text no. 14
Wu S, Baker C, Lang ME, Schrager SM, Liley FF, Papa C, et al. Nebulized hypertonic saline for bronchiolitis: A randomized clinical trial. JAMA Pediatr 2014;168:657-63.  Back to cited text no. 15
Luo Z, Fu Z, Liu E, Xu X, Fu X, Peng D, et al. Nebulized hypertonic saline treatment in hospitalized children with moderate to severe viral bronchiolitis. Clin Microbiol Infect 2011;17:1829-33.  Back to cited text no. 16
Zhang L, Mendoza-Sassi RA, Wainwright C, Klassen TP. Nebulized hypertonic saline solution for acute bronchiolitis in infants. Cochrane Database Syst Rev 2008;4:CD006458. doi:10.1002/14651858.  Back to cited text no. 17
Silver AH, Esteban-Cruciani N, Azzarone G, Douglas LC, Lee DS, Liewehr S, et al. 3% Hypertonic Saline Versus Normal Saline in Inpatient Bronchiolitis: A Randomized Controlled Trial. Pediatrics 2015;136:1036-43.  Back to cited text no. 18
Mahesh Kumar KB, Karunakara BP, Manjunath MN, Mallikarjuna HB. Aerosolised hypertonic saline in hospitalized young children with acute bronchiolitis: A randomized controlled clinical trial. J Pediat Sci 2013;5:e174.  Back to cited text no. 19


  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3], [Table 4]


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