Hypertonic Saline Versus Isotonic Saline Nasal Irrigation: Systematic Review and Meta-analysis

• Published in: American journal of rhinology & allergy Vol. 32; no. 4; pp. 269 - 279
• Main Authors: Kanjanawasee, Dichapong, Seresirikachorn, Kachorn, Chitsuthipakorn, Wirach, Snidvongs, Kornkiat
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01-07-2018
• Subjects: isotonic saline; sinonasal disease; sinonasal outcome test; hypertonic saline; rhinitis; mucociliary clearance; nasal lavage; rhinosinusitis; nasal irrigation; randomized controlled trial
• ISSN: 1945-8924; 1945-8932
• DOI: 10.1177/1945892418773566

Background
Saline nasal lavage is one of the treatments of sinonasal diseases. Evidence
from basic research favors hypertonic saline (HS) over isotonic saline (IS)
for mucociliary clearance, but evidence from clinical studies is
controversial. Conversely, HS may carry greater side effects.
Objective
To compare the effects of HS and IS nasal irrigation in treating sinonasal
diseases.
Methods
Systematic search with Ovid MEDLINE, Scopus, PubMed, Google Scholar, and
Manual additional sources was conducted. Randomized controlled trials
comparing HS with IS nasal irrigation in treating any sinonasal diseases,
including rhinitis and rhinosinusitis, were included. Data were pooled for
meta-analyses. Outcomes were symptom scores, sinonasal outcome test (SNOT),
and adverse events. Heterogeneity was explored by subgroup analyses.
Results
Nine studies (740 patients) were included. HS nasal irrigation brought
greater benefits over IS in symptom reduction (standardized mean difference
(SMD) −0.58; 95% confidence interval [CI]: −0.76, −0.40); however, no
difference was shown in SNOT-20 improvement (mean difference 1.81; 95% CI:
−0.68, 4.30). In subgroup analyses, effects favoring HS on symptoms were
larger in 4 subgroups. These were (1) patients with rhinitis (SMD −1.09; 95%
CI: −1.42, −0.76) compared with rhinosinusitis (SMD −0.37; 95% CI: −0.58,
−0.15), P < .01; (2) patients under the age of 18 years
(SMD −1.22; 95% CI: −1.53, −0.91) compared with patients over the age of 18
years (SMD −0.26; 95% CI: −0.49, −0.04), P < .01; (3)
saline irrigation using high volume (SMD −0.89; 95% CI: −1.18, −0.60)
compared with low volume (SMD −0.39; 95% CI: −0.62, −0.16),
P < .01; and (4) saline irrigation with
hypertonicity of <3% (SMD −1.09; 95% CI: −1.42, −0.76) and hypertonicity
of 3%–5% (SMD −1.20; 95% CI: −1.61, −0.78) compared with hypertonicity of
>5% (SMD 0.20; 95% CI: −0.15, 0.55), P < .01.
Buffered saline and operative status did not have impact. HS brought greater
minor adverse effects. No major adverse effects were reported.
Conclusion
HS improves symptoms over IS nasal irrigation in treating sinonasal diseases.
There is no difference in disease-specific quality of life. However, HS
brings greater minor side effects than IS.