The Section of Otolaryngology–Head and Neck Surgery, The University of Chicago Medical Center, The Pritzker School of Medicine, The University of Chicago, Illinois, USA.
Allergy Asthma Proc. 2011 May-Jun;32(3):206-12. doi: 10.2500/aap.2011.32.3442.
Intranasal carbon dioxide (CO(2)) was shown to reduce symptoms of seasonal allergic rhinitis (SAR). This study was designed to evaluate the effect of CO(2) on nasal allergen challenge. We conducted a randomized, controlled, crossover trial in 12 subjects with SAR outside their pollen season. Thirty minutes after a 20-second exposure to CO(2) or no exposure, subjects underwent a unilateral, localized, nasal allergen challenge. Filter paper disks were placed on the nasal septum to deliver a sham challenge followed by 2 increasing doses of either grass or ragweed allergen. Secretions were collected from both sides of the septum to evaluate the nasonasal reflex and were assayed for histamine. Nasal and eye symptoms were recorded. The primary outcome measure was the contralateral, reflex, secretory response to allergen as measured by secretion weights. Secondary outcome measures included ipsilateral nasal secretion weights, nasal and eye symptoms, levels of histamine in nasal secretions, and eosinophils in nasal scrapings. Subjects reported a transient burning sensation during exposure to CO(2). Compared with no treatment, active treatment resulted in a significant reduction in sneezes (p = 0.05), contralateral secretion weights (p = 0.04), and bilateral runny nose symptoms (p = 0.01). Ipsilateral secretion weights were numerically reduced. Histamine levels in ipsilateral nasal secretions increased significantly when the subjects received sham treatment but did not increase after pretreatment with CO(2). Treatment with nasal CO(2) resulted in partial reduction of the acute response to allergen challenge. Reflex responses were reduced, supporting an effect on neuronal mechanisms, which predict usefulness in the treatment of allergic rhinitis. Registered with the U.S. National Institutes of Health clinicaltrials.gov. Identifier: NCT00618410.
鼻腔内二氧化碳（CO2）已被证实可减轻季节性过敏性鼻炎（SAR）的症状。本研究旨在评估 CO2 对鼻内变应原激发的影响。我们在花粉季节外进行了一项 12 例 SAR 患者的随机、对照、交叉试验。在 20 秒暴露于 CO2 或不暴露后 30 分钟，患者接受单侧、局部、鼻内变应原激发。将滤纸盘置于鼻中隔上，进行假激发，然后递增强度逐渐增加的草或豚草过敏原。从鼻中隔两侧收集分泌物，以评估鼻-咽反射，并检测组胺。记录鼻和眼部症状。主要观察指标为过敏原激发后对侧分泌反应的重量。次要观察指标包括同侧鼻分泌物重量、鼻和眼部症状、鼻分泌物中组胺水平和鼻刮取物中的嗜酸性粒细胞。与不治疗相比，治疗组打喷嚏（p = 0.05）、对侧分泌物重量（p = 0.04）和双侧流鼻涕症状（p = 0.01）显著减少。同侧分泌物重量也有减少趋势。当患者接受假治疗时，同侧鼻分泌物中的组胺水平显著增加，但在 CO2 预处理后并未增加。鼻内 CO2 治疗导致变应原激发的急性反应部分减轻。反射反应减少，支持对神经元机制的影响，这预示着对过敏性鼻炎治疗的有用性。在美国国立卫生研究院临床试验.gov 注册。标识符：NCT00618410。
