Secretions and aerodigestive function (Hunting et al., 2023)

Purpose: Accumulated pharyngo-laryngeal secretions are associated with dysphagia, aspiration, and poor health outcomes. Despite ongoing developments in the evaluation of pharyngo-laryngeal secretions, understanding of the underlying mechanisms is limited. Pathophysiology associated with accumulated secretions is needed to guide tailored, targeted treatment pathways. This study reports the prevalence of accumulated pharyngo-laryngeal secretions in a large acute care caseload and explores the relationship between secretions and aerodigestive function.

Method: Consecutive inpatients (N = 222) referred for flexible endoscopic evaluation of swallow (FEES) with suspected dysphagia following assessment by a speech-language pathologist were recruited (43% neurological, 22% neurosurgical, 20% critical care, 15% other), and 250 standardized FEES were completed (222 first FEES, 28 repeat FEES). The assessment protocol included secretion assessment using the New Zealand Secretion Scale (NZSS), pharyngeal squeeze maneuver, laryngeal motor and sensory assessment, Penetration-Aspiration Scale, and Yale Pharyngeal Residue Severity Rating Scale. Urge-to-clear ratings were collected during endoscopy. Cough peak expiratory flow and swallow frequency measures were also collected, as well as clinical outcomes at time of discharge.

Results: There was a high incidence of accumulated secretions, with 77% of inpatients having elevated NZSS (Mdn = 3, range: 0–7) and 37% with pooled laryngeal secretions. Accumulated secretions were associated with reduced swallow frequency, reduced laryngeal adductor reflex, impaired pharyngeal squeeze maneuver, and peak expiratory flow. NZSS scores also correlated with swallow measures (Penetration-Aspiration Scale and Yale Pharyngeal Residue Severity Rating Scale) and patient outcomes including diet recommendations at discharge and pneumonia during admission.

Conclusions: This large study contributes to evidence associating both sensory and motor impairments with secretion accumulation and aspiration risk. Further exploration of the key physiological mechanisms contributing to accumulated secretions will serve as markers to provide proof of principle for targets for secretion management protocols.

Supplemental Material S1. Subgroup regression analysis: Patient Outcomes – FEES findings.

Supplemental Material S2. Subgroup regression analyses: NZSS score outcomes - physiological measures across diagnostic groups and acuity (ICU, intubation, tracheostomy).

Hunting, A., Steffanoni, B., Jacques, A., & Miles, A. (2023). Accumulated secretions and associated aerodigestive function in patients with dysphagia. American Journal of Speech-Language Pathology, 32(6), 2691–2701. https://doi.org/10.1044/2023_AJSLP-23-00118