Corticosteroid-LABA inhalers increase phonation threshold pressure (PTP) and flow (PTF) in rabbits.

OBJECTIVES: This study examined the effects of a combination corticosteroid plus long-acting beta2 -adrenergic agonist inhaler (IC) on rabbit phonation. METHODS: White New Zealand male rabbits were assigned randomly to experimental and control groups (n = 11 per group). The experimental group received twice-daily doses of Advair HFA™ (fluticasone propionate 45 mcg and salmeterol 21 mcg) via a veterinary facemask with 1-way valve and spacer; the control group received aerosolized saline. After 8 weeks, animals were euthanized, larynges excised, frozen, and subsequently thawed and mounted on a standard bench apparatus. Phonation was elicited during 15 successive trials, and phonation threshold pressure (PTP; cmH2 O) and flow (PTF; L/min) were quantified. RESULTS: Repeated measures analysis of variance indicated significant differences between the experimental and control groups (p < 0.05). Mean PTP and PTF values were higher (worse) for rabbits that received Advair HFA™. CONCLUSION: Following 8-week exposure to ICs, rabbit larynges required greater air pressure and flow to initiate phonation. Because even modest phonation onset differences can have a meaningful clinical impact on voice function, these findings suggest that LABA ICs may put patients at risk for voice disorders. Furthermore, these voice disorders may occur within a relatively short timeframe. The results from this study have important clinical implications for voice care in those who use ICs. LEVEL OF EVIDENCE: NA Laryngoscope, 133:2680-2686, 2023.

Physiology of Dysphagia in Those with Unilateral Vocal Fold Immobility.

Quantitative measures of swallowing function were extracted from modified barium swallowing studies (MBS) to characterize swallowing pathophysiology in patients with unilateral vocal fold immobility (UVFI). All individuals with UVFI completing a MBS during the prior 5 years were included. Demographic information, penetration-aspiration score, timing of aspiration and quantitative measures from the MBS were extracted from electronic medical records and compared across 1, 3, and 20 cc liquid bolus swallows. UVFI patient measures were compared to normal age-matched controls to identify swallowing pathophysiology associated with aspiration. The incidence of aspiration by UVFI etiology groups (i.e., central nervous system, idiopathic, iatrogenic, skull base tumor, or peripheral tumor) was also compared. Of the 61 patients who met inclusion criteria, aspiration was observed in 23%. Maximum pharyngeal constriction was abnormal in 79% of aspirators compared to 34% of non-aspirators (p = .003). Delay in airway closure was the most common swallowing abnormality identified in the study population (62%) but was not associated with aspiration. Among the 14 individuals who aspirated, the iatrogenic and skull base tumor etiology groups comprised the majority (i.e., 36% each). However, the incidence of aspiration for the iatrogenic group was 19% compared to 50% of the skull base tumor group. Aspiration in patients with UVFI was associated with abnormally reduced pharyngeal constriction. Delayed airway closure was common in both aspirators and non-aspirators.

Pathophysiology of aspiration in a unilateral SLN lesion model using quantitative analysis of VFSS.

OBJECTIVE: The purpose of this study was to elucidate the pathophysiology of aspiration in previously studied female infant piglets after a unilateral superior laryngeal nerve (uSLN) lesion. METHODS: Videofluoroscopic swallow studies (VFSS) were acquired from 15 female piglets ages 2-3 weeks (9 with uSLN lesion and 6 controls). VFSS were analyzed at 30 frames/second sampling rate. Quantitative measures were conducted and compared between groups using published methodologies for VFSS assessment in adult and infant humans. Measures included the: 1) number of lingual-palatal contacts (LPC) (i.e. pre-swallow), 2) total pharyngeal transit time (TPT), 3) offset of swallow (offP), as well as onset of: 4) pharyngeal stage (onP), 5) pharyngoesophageal segment opening (oPES), 6) maximum PES opening (maxPES), 7) airway closure onset (oAC), and 8) maximum airway closure (maxAC). Measures 5-7 were determined relative to onP. Bolus residue was rated by severity (0 (none) to 3 (severe)). A gamma regression was used to compare continuous measures between lesioned and control groups. RESULTS: The number of LPC (p = .006), TPT (p = .023) and timing of maxAC (p = .041) were significantly greater in the uSLN lesion than the control group. CONCLUSIONS: Outcomes of this study replicated prior published findings and elucidated that piglets with right uSLN lesions exhibited delayed maxAC. Noteworthy was the use of clinically relevant quantitative videofluoroscopic measures in piglets for comparison to future studies in human pediatric populations.

Prevalence, incidence, and characteristics of dysphagia in those with unilateral vocal fold paralysis.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to investigate the impact of dysphagia definition on the incidence and overall prevalence of dysphagia in patients with unilateral vocal fold paralysis (UVP) stratified by etiology. STUDY DESIGN: Retrospective medical chart review. METHODS: Data was collected from the records of individuals diagnosed with UVP from 2013 to 2018, including patient demographics, dysphagia questionnaire total scores, clinical evaluation dysphagia symptoms, and instrumental swallow assessment outcomes. The annual incidence and overall prevalence of dysphagia were calculated by etiology as counts and percentages across five operational definitions of dysphagia. RESULTS: A total of 415 individuals met inclusion criteria for the study. Annual prevalence estimates ranged from 19% to 55%, depending on the definition of dysphagia used. The highest prevalence of dysphagia occurred when defined by symptoms or signs identified by the clinician (55%). The lowest prevalence of dysphagia occurred using a definition of abnormal swallowing function documented during instrumental assessment (19%). Dysphagia questionnaire scores were more frequently abnormal in those with iatrogenic than idiopathic etiology of UVP (adjusted P = 0.014). Rate of instrumental assessment and documentation of aspiration was highest for central UVP etiology (33%). On average, pneumonia was rare (6%) irrespective of UVP etiology. CONCLUSION: Up to 55% of patients diagnosed with UVP complained of dysphagia, but only 21% had dysphagia symptoms severe enough to prompt instrumental assessment. Incidence and severity of dysphagia varied depending on UVP etiologic category as well as dysphagia definition. The etiology of UVP may impact dysphagia risk and severity in this population and warrants further investigation. LEVEL OF EVIDENCE: IV Laryngoscope, 130:2397-2404, 2020.