The implications of variations in nasal irrigation recipes in the United Kingdom.

Objective: This study aims to investigate the variations in publicly available nasal irrigation recipes published in the United Kingdom (UK).
Design: Internet searches used to identify eligible nasal irrigation recipes. These were then examined for their physical and biochemical properties, through theoretical calculations and experimental measurement.
Setting: Recipes produced by healthcare providers or official national bodies in the UK.
Participants: No human participants.
Main Outcome Measures: Solution osmolality (classified into hypo-, iso- and hypertonic), acidity (pH) and specific gravity.
Results: Thirteen unique recipes were identified from 17 sources. Osmolality ranged from 166.2 to 1492.2 mosmol/kg in volumes ranging from 142 to 1136 mLs (isotonic range 275-295 mosmol/kg). Specific gravity ranged from 1.006 to 1.034. pH ranged from 7.74 to 8.11. No recipe produced a solution with isotonic properties. The majority produced hypertonic irrigations.
Conclusions: Most publicly available nasal irrigation recipes produce hypertonic solutions but there is great variability in the osmolality and volume. UK organisations should take action to review published recipes to bring these into alignment with latest guidelines (recommending against hypertonic saline use) and reduce variability in patient interpretations.
(© 2020 John Wiley & Sons Ltd.)