Surface active agents in sputum evacuation: a blind comparison with normal saline solution and distilled water

Intranasal instillation of distilled water, hypertonic saline and sodium bicarbonate promotes redox imbalance and acute lung inflammation in adult mice

Bronchial obstruction, caused by retained secretions, is often treated by the administration of mucoactive agents including distilled water, saline, hypertonic saline, and sodium bicarbonate. However, the inflammatory effect of these solutions on the lungs remains unclear. This study evaluated the instillation effects of different solutions on oxidative stress and lung inflammatory response in C57BL/6 mice. Fifty C57BL/6 mice were divided into 5 groups: control (CG); distilled water (DWG), hypertonic saline (HSG), saline (SG) and sodium bicarbonate (SBG). CG was exposed to ambient air while DWG, HSG, SG and SBG had 50 μl of respective solutions administered intranasally for 5 consecutive days. Twenty-four hours after the last intranasal instillation, all animals were euthanized for subsequent analysis. All solutions promoted increased recruitment of inflammatory cells to the lung compared to controls. Superoxide dismutase activity was lower in HSG compared to all other groups; catalase activity was reduced in SG, while it increased in SBG and DWG compared to CG. Finally, there was an increase in the inflammatory markers TNF-α, CCL2 and IFN-γ in DWG compared to CG, SG and HSG. In conclusions, the intranasal instillation of different solutions promotes redox imbalance and inflammation on lungs of adult mice.

Mucoactive agents for chronic, non-cystic fibrosis lung disease: A systematic review and meta-analysis

Inhaled mucoactive agents are used in respiratory disease to improve mucus properties and enhance secretion clearance. The effect of mannitol, recombinant human deoxyribonuclease/dornase alfa (rhDNase) and hypertonic saline (HS) or normal saline (NS) are not well described in chronic lung conditions other than cystic fibrosis (CF). The aim of this review was to determine the benefit and safety of inhaled mucoactive agents outside of CF. We searched Medline, Embase, CINAHL and CENTRAL for randomized controlled trials investigating the effects of mucoactive agents on lung function, adverse events (AEs), health-related quality of life (HRQOL), hospitalization, length of stay, exacerbations, sputum clearance and inflammation. There were detrimental effects of rhDNase in bronchiectasis, with average declines of 1.9-4.3% in forced expiratory volume in 1 s (FEV₁ ) and 3.7-5.4% in forced vital capacity (FVC) (n = 410, two studies), and increased exacerbation risk (relative risk = 1.35, 95% CI = 1.01-1.79 n = 349, one study). Some participants exhibited a reduction in FEV₁ (≥10-15%) with mucoactive agents on screening (mannitol = 158 of 1051 participants, rhDNase = 2 of 30, HS = 3 of 80). Most AEs were mild and transient, including bronchospasm, cough and breathlessness. NS eased symptomatic burden in COPD, while NS and HS improved spirometry, HRQOL and sputum burden in non-CF bronchiectasis. Mannitol improved mucociliary clearance in asthma and bronchiectasis, while the effects of N-acetylcysteine were unclear. In chronic lung diseases outside CF, there are small benefits of mannitol, NS and HS. Adverse effects of rhDNase suggest this should not be administered in non-CF bronchiectasis.

Long-term exposure to ultrasonically nebulized distilled water and saline causes cellular influx and oxidative stress in lung tissue of rats

PURPOSE

The aim of this study was to evaluate of the effect of distilled water and saline ultrasonic nebulization on the inflammatory and oxidative stress responses and on the lower airway architecture.

MATERIALS AND METHODS

Twenty-one male Fischer rats were distributed into 3 groups of 7 animals each: a control group (CG), exposed to ambient air; a saline group (SG), exposed to 0.9% sodium chloride (NaCl); and a group exposed to distilled water (DWG). The exposure was carried out in a box attached to an ultrasonic inhaler, occurring for 20 min, 3 times a day for 6 months. At 24h after the last exposure, the animals were euthanized. The bronchoalveolar lavage fluid (BALF) and lungs were collected for study.

RESULTS

There was an increase of inflammatory cells in the pulmonary tissue BALF in the DWG compared with the CG. The DWG showed an increase of inflammatory cells compared with the SG and CG. The DWG and SG had higher NADPH oxidase activity than the CG. The volume density (Vv) of the alveolar septum was higher in the DWG than in the SG and CG, and the DWG also had a higher Vv of collagen fibers than the other 2 groups. The DWG presented elevated content of thiobarbituric acid reactive substances in lung homogenates relative to the SG and CG.

CONCLUSIONS

The ultrasonic nebulization of distilled water increased the influx of inflammatory cells and oxidative damage, and promoted changes in the lung architecture.

Mucolytic Effectiveness of Tyloxapol in Chronic Obstructive Pulmonary Disease - A Double-Blind, Randomized Controlled Trial

Objective

Mucoactive drugs should increase the ability to expectorate sputum and, ideally, have anti-inflammatory properties. The aim of the study was to evaluate the mucolytic activity of Tyloxapol compared to saline (0.9%) in COPD.

Design

A randomized, placebo-controlled, double-blinded crossover, clinical trial was carried out. Patients were randomly assigned to either inhale 5 ml Tyloxapol 1% or saline 0.9% solution three times daily for 3 weeks and vice versa for another 3 weeks. 28 patients (18 male, 10 female, 47 to 73 years old, median age 63.50) were screened, 21 were treated and 19 patients completed the study per protocol.

Results

A comparison of the two treatment phases showed that the primary endpoint sputum weight was statistically significant higher when patients inhaled Tyloxapol (mean 4.03 g, 95% CI: 2.34–5.73 g at week 3) compared to saline (mean 2.63 g, 95% CI: 1.73–3.53 g at week 3). The p-value at three weeks of treatment was 0.041 between treatment arms. Sputum cells decreased during the Tyloxapol treatment after 3 weeks, indicating that Tyloxapol might have some anti-neutrophilic properties. Lung function parameters (FVC, FEV₁, RV, and RV/TLC) remained stable during the study, and no treatment effect was shown. Interestingly, there was a mean increase in all inflammatory cytokines (IL-1β, IL-6, and IL-8) during the saline treatment from day 1 to week 3, whereas during the Tyloxapol treatment, all cytokines decreased. Due to the small sample size and the large individual variation in sputum cytokines, these differences were not significant. However, analyses confirmed that Tyloxapol has significant anti-inflammatory properties in vitro. Despite the high number of inhalations (more than 1000), only 27 adverse events (20 during the Tyloxapol and seven during saline) were recorded. Eleven patients experienced AEs under Tyloxapol and six under saline treatment, which indicates that inhalation of saline or Tyloxapol is a very safe procedure.

Conclusion

Our study demonstrated that inhalation of Tyloxapol by patients with COPD is safe and superior to saline and has some anti-inflammatory effects.

Trial Registration

ClinicalTrials.gov NCT02515799