The effect of oral guaifenesin on pediatric chronic rhinitis: A pilot study.

OBJECTIVES: To investigate the effectiveness of guaifenesin in the relief of nasal symptoms in children with chronic rhinitis (CR). We hypothesized that guaifenesin use over a 14-day study period would improve subjective nasal complaints in pediatric patients with chronic rhinitis, as measured by the SinoNasal-5 (SN-5) survey. We also hypothesized improvement in nasal volume and cross-sectional area with guaifenesin. STUDY DESIGN: Randomized, placebo-controlled, parallel group, masked clinical trial. METHODS: The study consisted of a 14-day, randomized, placebo-controlled, parallel group, masked clinical trial of oral guaifenesin for CR in children aged 7-18 years. A 2:1 ratio of subjects on active medication to placebo was used. The study was approved by the Western Institutional Review Board. On initial enrollment and at the conclusion of therapy, the SN-5 was completed by parents, acoustic rhinometry measurements performed, and mucus sampling for rheology was obtained. RESULTS: 30 subjects were enrolled in the study, with 20 receiving guaifenesin and 10 placebo. Treatment with guaifenesin for 14 days produced a significant mean change towards clinical improvement in SN-5 scores compared with placebo (p = 0.013). There was no significant difference in quality of life assessment scores between the two groups or in any of the acoustic rhinometry parameters. Many of the study subjects had difficulty producing a mucus sample sufficient for analysis. CONCLUSIONS: Based upon our pilot data, it appears that guaifenesin treatment may produce objective improvements in pediatric patients with CR. Further research with larger samples sizes, inclusion of children younger than 6, and biophysical mucus analyses is warranted. LEVEL OF EVIDENCE: Level 2b.

Endotracheal Tube Seal and Suction Performance in a Novel Biorealistic Tracheal Model.

BACKGROUND: Endotracheal tube (ETT) cuffs create a seal to protect against secretion entry to the lungs. Cuff inflation currently is recommended at 20-30 cm H2O pressure. ETT designs have variable seal performance in bench studies using rigid tracheal models lacking the dynamic characteristics of the human trachea. We compared ETT designs within a new, biorealistic tracheal model to assess cuff and suction performance in the setting of a compliant trachea. METHODS: Three ETT designs (Mallinckrodt Hi-Lo, KimVent Microcuff, and Sheridan/HVT) were tested for performance by simulant leakage below the cuff and air leakage (measured as return tidal volume ≥ 80% delivered) over a range of cuff (5-25 cm H2O) and end-expiratory pressure (PEEP 0-15 cm H2O). Subglottic suction channel performance was tested in 2 ETTs (TaperGuard Evac [Covidien] and ISIS HVT [Teleflex]) as time to evacuate the simulant. RESULTS: All ETT cuffs provided effective seals at an inflation pressure of 12 cm H2O when PEEP was ≤ 5 cm H2O. The Microcuff ETT sealed at the lowest pressure of 6 cm H2O, whereas the Sheridan/HVT cuff sealed at 12 cm H2O (P = .01). With a PEEP of 15 cm H2O, a reciprocal increase in air leak occurred, requiring a cuff inflation up to 22 cm H2O to maintain a return tidal volume at ≥ 80% delivered. Suction channel performance improved in the lateral position compared with supine for both ETT designs during continuous 15 mm Hg suction pressure (P = .001). CONCLUSIONS: Within a novel model with normal trachea compliance, we found all ETT designs tested to seal at lower than current recommended cuff pressures.

Guaifenesin has no effect on sputum volume or sputum properties in adolescents and adults with acute respiratory tract infections.

BACKGROUND: Guaifenesin (glyceryl guaiacolate ether [GGE]) has been studied as a cough suppressant and as an expectorant; however, published studies to date have failed to find a consistent benefit. METHODS: An 8-day multi-center clinical trial was conducted to study the effect of two 600-mg extended-release GGE tablets twice daily for 1 week on cold symptoms, sputum volume, and properties in adolescents and adults with productive cough from an acute respiratory tract infection (RTI). The study enrolled 378 subjects (GGE, n = 188; and placebo, n = 190) who were otherwise healthy and had an RTI for up to 5 days before enrollment. Subjects suffered from at least 2 of 3 symptoms of cough, thickened mucus, and chest congestion. A total of 151 GGE and 144 control subjects completed the full protocol. Single-sputum samples were collected from each subject on days 1, 3, 4, and 8 of the study. The rheology and interfacial tension of sputum were measured, and 24-h collected samples from days 1 and 4 were analyzed for total volume and hydration. RESULTS: Symptoms in both the GGE and placebo groups improved to a similar degree over time. There were no significant differences between the GGE and placebo groups for sputum volume (P = .41), percent solids (P = .69), interfacial tension (P = .88), elasticity (P = .71), viscosity (P = .45), or mechanical impedance (P = .75). CONCLUSIONS: The recommended dose of GGE had no measurable effect on sputum volume or properties and is unlikely to be an expectorant or mucolytic when used to treat acute RTI. (ClinicalTrials.gov registration NCT01046136.).