Limited evidence: higher efficacy of nasal saline irrigation over nasal saline spray in chronic rhinosinusitis--an update and reanalysis of the evidence base.

To assess the effectiveness of nasal saline irrigation in adult patients with chronic rhinosinusitis. PubMed, EMBASE, the Cochrane Library. A comprehensive search was performed, and 2 authors independently screened publications. The design of selected studies was assessed on directness of evidence and risk of bias. Of 1596 publications, 1 open-label randomized trial with high directness of evidence and moderate risk of bias was included. In this study, 127 patients were randomly allocated to isotonic nasal saline irrigation or isotonic nasal saline spray, as added to their usual medication. The mean 20-Item Sinonasal Outcome Test (SNOT-20) scores of those treated with nasal irrigation improved more than those allocated to nasal spray. While the authors consider an improvement of 16 or more to be clinically meaningful, the changes from baseline in mean SNOT-20 scores of those treated with irrigation (and the differences with those treated with nasal spray) at 2, 4, and 8 weeks were 12.2 (difference 5.5, [95% confidence interval -0.04 to 11.0]), 16.2 (difference 8.8 [3.2 to 14.4]), and 15.0 (difference 6.5 [0.4 to 12.6]), respectively. Side effects of posttreatment nasal dripping were common but minor and did not lead to discontinuation of treatment. It should be explained to adult patients with chronic rhinosinusitis that there is limited information on the relative effect of nasal saline irrigation and nasal saline spray on subjective symptom improvement, since there is only 1 trial available with a moderate risk of bias showing limited benefit of irrigation over spray.