Mechanical Properties of the Upper Airway

Abstract

The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions.

Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic–hypercapnic gas challenges in conscious mice

“…Expiration during eupneic breathing is passive and occurs via simple elastic recoil of the lungs (Mitchell et al, 1975; St-John and Paton, 2004; Garcia et al, 2011). In contrast, disordered breathing is characterized by abnormal breaths (disturbed balance of inspiratory and expiratory volume per breath) during rest, and the presence of recurrent spontaneous apneas (pauses), sighs and sniffs, and irregular breaths due to abrupt movements such as grooming and locomotor activity (Han and Strohl, 2000; Han et al, 2001, 2002; Price et al, 2003; Strohl, 2003; Yamauchi et al, 2007, 20008a,b,c, 2010; Chai et al, 2011; Gillombardo et al, 2012; Strohl et al, 2012). …”

Insights since FDA Approval of Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

“…A favorable AP collapse on DISE can still present in those with BMI values >35 kg/m 2 . BMI has some correlation to higher critical closing pressure 60 , but centers are now more focused on the results of DISE to rule out a complete concentric collapse. For implant success related to postoperative tongue motions, nerve integrity monitoring is used to predict correct cuff placement in one of the groups with the higher success rates 24 .…”

What can impulse oscillometry and pulmonary function testing tell us about obstructive sleep apnea: a case-control observational study?

“…Inability to maintain upper airway (UA) patency during sleep is a cause of obstructive sleep apnea (OSA) and its sequelae [1,2]. OSA affects ≥4 % of men and ≥2 % of women [3].…”