Tracheal pressure in horses with signs of dorsal displacement of the soft palate

Roethlisberger-Holm, K.

doi:10.1111/j.2042-3306.1995.tb04893.x

Cited by 7 publications

(2 citation statements)

References 8 publications

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“…The airway pressure profile of DDSP, induced by hypoglossal nerve block, is similar to that found in horses with naturally occurring DDSP (18,42,44). The condition produces an expiratory obstruction (increased expiratory tracheal pressure) and diversion of airflow through the mouth (reduced inspiratory and expiratory pharyngeal pressures).…”

Section: Physiological Significancesupporting

confidence: 57%

Role of the hypoglossal nerve in equine nasopharyngeal stability

Cheetham¹,

Pigott²,

Hermanson³

et al. 2009

Journal of Applied Physiology

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The equine upper airway is highly adapted to provide the extremely high oxygen demand associated with strenuous aerobic exercise in this species. The tongue musculature, innervated by the hypoglossal nerve, plays an important role in airway stability in humans who also have a highly adapted upper airway to allow speech. The role of the hypoglossal nerve in stabilizing the equine upper airway has not been established. Isolated tongues from eight mature horses were dissected to determine the distal anatomy and branching of the equine hypoglossal nerve. Using this information, a peripheral nerve location technique was used to perform bilateral block of the common trunk of the hypoglossal nerve in 10 horses. Each horse was subjected to two trials with bilateral hypoglossal nerve block and two control trials (unblocked). Upper airway stability at exercise was determined using videoendoscopy and measurement of tracheal and pharyngeal pressure. Three main nerve branches were identified, medial and lateral branches and a discrete branch that innervated the geniohyoid muscle alone. Bilateral hypoglossal block induced nasopharyngeal instability in 10/19 trials, and none of the control trials (0/18) resulted in instability (P<0.001). Mean treadmill speed (+/-SD) at the onset of instability was 10.8+/-2.5 m/s. Following its onset, nasopharyngeal instability persisted until the end of the treadmill test. This instability, induced by hypoglossal nerve block, produced an expiratory obstruction similar to that seen in a naturally occurring equine disease (dorsal displacement of the soft palate, DDSP) with reduced inspiratory and expiratory pharyngeal pressure and increased expiratory tracheal pressure. These data suggest that stability of the equine upper airway at exercise may be mediated through the hypoglossal nerve. Naturally occurring DDSP in the horse shares a number of anatomic similarities with obstructive sleep apnea. Study of species with extreme respiratory adaptation, such as the horse, may provide insight into respiratory functioning in humans.

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Section: Physiological Significancesupporting

confidence: 57%

Role of the hypoglossal nerve in equine nasopharyngeal stability

Cheetham¹,

Pigott²,

Hermanson³

et al. 2009

Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…Therefore, the first step in unravelling the aetiopathogenesis of this condition is to determine if NCTs affected with DLC differ from normal, elite NCTs based on simple airway mechanics measurements. Tracheal pressure measurements during inspiration and expiration have often been used to determine the type and degree of URT obstruction in exercising horses (Lumsden et al 1993;Ducharme et al 1994;Rehder et al 1995;Roethlisberger-Holm 1995;Tetens et al 1996). Subjective clinical assessment of affected NCTs based upon endoscopic examination, palpation and laryngotomy surgery suggests that affected Effect of poll flexion and dynamic laryngeal collapse on tracheal pressure in Norwegian Coldblooded Trotter racehorses 60 Effect of poll flexion and dynamic laryngeal collapse on tracheal pressure individuals have narrower rima glottidis (in height and width) relative to the elite individuals of this breed.…”

Section: Introductionmentioning

confidence: 99%