Effectiveness of steam inhalation and nasal irrigation for chronic or recurrent sinus symptoms in primary care: a pragmatic randomized controlled trial

Background:Systematic reviews support nasal saline irrigation for chronic or recurrent sinus symptoms, but trials have been small and few in primary care settings. Steam inhalation has also been proposed, but supporting evidence is lacking. We investigated whether brief pragmatic interventions to encourage use of nasal irrigation or steam inhalation would be effective in relieving sinus symptoms.Methods:We conducted a pragmatic randomized controlled trial involving adults (age 18–65 yr) from 72 primary care practices in the United Kingdom who had a history of chronic or recurrent sinusitis and reported a “moderate to severe” impact of sinus symptoms on their quality of life. Participants were recruited between Feb. 11, 2009, and June 30, 2014, and randomly assigned to 1 of 4 advice strategies: usual care, daily nasal saline irrigation supported by a demonstration video, daily steam inhalation, or combined treatment with both interventions. The primary outcome measure was the Rhinosinusitis Disability Index (RSDI). Patients were followed up at 3 and 6 months. We imputed missing data using multiple imputation methods.Results:Of the 961 patients who consented, 871 returned baseline questionnaires (210 usual care, 219 nasal irrigation, 232 steam inhalation and 210 combined treatment). A total of 671 (77.0%) of the 871 participants reported RSDI scores at 3 months. Patients’ RSDI scores improved more with nasal irrigation than without nasal irrigation by 3 months (crude change −7.42 v. −5.23; estimated adjusted mean difference between groups −2.51, 95% confidence interval −4.65 to −0.37). By 6 months, significantly more patients maintained a 10-point clinically important improvement in the RSDI score with nasal irrigation (44.1% v. 36.6%); fewer used over-the-counter medications (59.4% v. 68.0%) or intended to consult a doctor in future episodes. Steam inhalation reduced headache but had no significant effect on other outcomes. The proportion of participants who had adverse effects was the same in both intervention groups.Interpretation:Advice to use steam inhalation for chronic or recurrent sinus symptoms in primary care was not effective. A similar strategy to use nasal irrigation was less effective than prior evidence suggested, but it provided some symptomatic benefit. Trial registration: ISRCTN, no. 88204146.Rhinosinusitis probably affects more than 25 million Americans and 2.5 million Canadians.¹ Quality of life of patients with chronic or recurrent sinusitis has been reported to be similar to congestive heart disease and chronic pulmonary disease.² Antibiotics are prescribed for nearly all patients with sinusitis,³ but the evidence is modest⁴ and an international priority is to contain antibiotic resistance.⁵ Steam inhalation is widely advocated in rhinosinusitis, but a Cochrane review of steam for the “common cold” found equivocal evidence,⁶ and a recent primary care trial found no benefit and some harm (mild thermal injury) for pragmatic advice to inhale steam twice daily for a range of respiratory tract infections.⁷ The Cochrane review of nasal saline irrigation reported benefit.⁸ However, most of the trials were small, mainly from secondary care settings, and the review documented symptom data from only 129 participants, with high heterogeneity. Two small randomized controlled trials included some participants from primary care settings.^9,10 One of the studies compared a gravity-based nasal irrigation device with routine care among 76 participants mainly from primary care settings; it found that symptoms improved very little in the control group (by 1 point on the Rhinosinusitis Disability Index [RSDI] converted to a 100-point scale), as compared with a 14-point improvement in the irrigation group.⁹ The other (published since the Cochrane review) compared a positive-pressure squeeze bottle with saline nasal spray among 121 volunteers from various sources and found an 8.5-point improvement in the control group, as compared with a 15-point improvement in the irrigation group.¹⁰We conducted a large pragmatic randomized controlled trial of the effectiveness of brief advice to use nasal irrigation or steam inhalation in routine primary care for chronic or recurrent sinus symptoms.     

Feeding Kinematics and Nectar Intake of the Honey Bee Tongue

Most flower-visiting insects employ highly-evolved organs to feed themselves rapidly and efficiently on the floral nectar. A honey bee drives its segmented tongue (glossa) covered by dense hairs reciprocatingly to load nectar. A high-speed camera system ameliorated by a microscope revealed morphological changes in glossal surfaces during live honey bees’ nectar dipping and surface configurations through the stretching of postmortem honey bees’ glossae. Both the in vivo and postmortem observations reveal that shortening and lengthening of the glossal segments perform high concordance with the erection of glossal hairs, which aids in developing deformable gaps between rows of glossal hairs during nectar trapping. A model was proposed to evaluate the nectar-intake volume considering the experimentally-measured average erection angle and tongue elongation length during nectar feeding. The theoretical results fit the experimental data well and disclose that these two factors contribute to an augmentation of nectar-intake observably. We also theoretically present that the extendible and deformable glossae have advantages for the polylectic feeding behavior.