Dysphagia and medicine regimes in patients following lung transplant surgery: A retrospective review

The pathophysiology of dysphagia post-lung transplant: A systematic review

Purpose

One major consequence of lung transplantation is the development of oropharyngeal dysphagia. This systematic review aims to appraise and synthesize the available evidence of the use of instrumental assessments to outline the characteristics of post-lung transplant dysphagia.

Methods

Following the identification of appropriate search terms for the question, a literature search was conducted in PubMed, Scopus, and the Health and Medical Collection of Proquest Research Library and included records between inception and September 14, 2023. Search strategies included the use of text words and subject headings (e.g., MeSH and Index terms) related to (1) dysphagia or swallowing (swallow*, deglutition disorder*), (2) lung transplant (lung transplant*, post-operative, post-lung), and (3) complications (adverse effects, *complications, treatment outcome).

Results

The literature search strategy yielded a total of 883 studies from the electronic database search, with no additional records identified through other sources. After the removal of duplicates (n = 96), a total of 787 studies were screened through title and abstracts which eliminated 775 studies. Six studies were ultimately included in the systematic review. The selected articles included patients who underwent lung transplantation and all but one study utilized a retrospective design. A lack of transparency regarding instrumental evaluation protocols (videofluoroscopic [VFSS] and Flexible Endoscopic Evaluation of Swallowing [FEES]) including the number and bolus types used during the instrumental evaluations appeared as a theme in the studies included. The Penetration-Aspiration Scale (PAS) was systematically utilized to measure dysphagia safety outcome. Handling of the PAS scale was not consistent across studies, however penetration or aspiration ranged from 52.4% up to 100%. Additionally, silent aspiration rates ranged from 14.2% to 61.9%.

Conclusions

This review sought to describe the post-operative swallowing function and its physiological parameters following lung transplantation. We examined the results reported and the methods utilized in obtaining these results in the existing literature. Limited reporting practices for physiological parameters were found, however the airway invasion was reported in all studies with variation in degrees of swallowing safety related deficits, with PAS being the most widely used scale to describe airway invasion depth and response. Future studies exploring dysphagia outcomes post-lung transplant should comment on the altered physiological mechanisms of the swallow to further expand on the physiological deficits observed following transplantation in this group and allow for treatment planning.

Level of evidence

Level 1.

Characterizing Swallowing Impairment in a Post-Lung Transplant Population

BACKGROUND

Lung transplant recipients carry significant pre- and post-lung transplant dysphagia risk factors related to altered respiratory-swallow coordination as well as acute injury and decompensation resulting in the acute post-lung transplant recovery period. However, we are only beginning to understand the potential physiological contributors to altered swallowing in this population.

METHOD

A retrospective, cross-sectional, cohort study of post-lung transplant patients was performed. All participants received a modified barium swallow study (MBSS) as part of standard care during their acute hospitalization using the Modified Barium Swallow Impairment Profile (MBSImP) protocol and scoring metric. A combination of MBSImP scores, Penetration-Aspiration Scale (PAS) scores, Functional Oral Intake Scale (FOIS) scores, International Dysphagia Diet Standardization Initiative (IDDSI) scale levels, and the time from lung transplant to MBSS was collected, as well as measures of swallowing impairment and swallowing-related outcomes. Differences in swallowing physiology and swallowing-related outcomes between participants with typical versus atypical PAS were explored.

RESULTS

Forty-two participants met our prespecified inclusion criteria. We identified atypical laryngeal penetration and/or aspiration in 52.4% of our post-lung transplant cohort. Silent aspiration occurred in 75% of those patients who aspirated. Comparing typical versus atypical PAS scores, we found statistically significant associations with laryngeal elevation (Component 8), p < .0001; anterior hyoid excursion (Component 9), p = .0046; epiglottic movement (Component 10), p = .0031; laryngeal vestibule closure (Component 11), p < .0001; pharyngeal stripping (Component 12), p = .0058; pharyngeal total scores, p = .0001; FOIS scores, p = .00264; and IDDSI liquid levels, p = .0009.

CONCLUSIONS

Swallowing impairment resulting in abnormal bolus invasion is prevalent in post-lung transplant patients. Airway invasion in this cohort was related to pharyngeal swallow impairment and resulted in modified oral intake. Our findings help expand upon prior literature, which only reported the incidence of aspiration and pathological laryngeal penetration. Our results suggest that the potential for aerodigestive system impairment and negative sequela should not be underestimated in the post-lung transplant population.

A prospective examination of swallow and cough dysfunction after lung transplantation

OBJECTIVES

Swallow and cough dysfunction are possible surgical complications of lung transplantation (LT). We examined voluntary cough strength, sensorimotor reflexive cough integrity, and swallow-related respiratory rate (RR) across swallowing safety and aspiration response groups in recovering LT recipients.

METHODS

Forty-five LT recipients underwent flexible endoscopic evaluation of swallowing indexed by the validated Penetration Aspiration Scale. RR before and after a 3-ounce water drinking task was measured. Voluntary and reflexive cough screening were performed to index motor and sensory outcomes. T-tests, one-way ANOVAs, and chi-square (odds ratios) were used.

RESULTS

60% of patients exhibited laryngeal penetration (n = 27) and 40% demonstrated tracheal aspiration (n = 18); 72% (n = 13) demonstrated silent aspiration. Baseline RR was higher in aspirators versus non-aspirators (26.5 vs. 22.6, p = 0.04) and in silent aspirators compared to non-silent aspirators (27.9 vs. 20.7, p = 0.01). RR change post-swallowing did not differ between aspiration response groups; however, it was significantly higher in aspirators compared to non-aspirators (3 vs. -2, p = 0.02). Compared to non-silent aspirators, silent aspirators demonstrated reduced voluntary cough peak expiratory flow (PEF; 166 vs. 324 L/min, p = 0.01). PEF, motor and urge to cough reflex cough ratings did not differ between aspirators and non-aspirators. Silent aspirators demonstrated a 7.5 times higher odds of failing reflex cough screening compared to non-silent aspirators (p = 0.07).

CONCLUSIONS

During the acute recovery period, all LT participants demonstrated some degree of unsafe swallowing and reduced voluntary cough strength. Silent aspirators exhibited elevated RR, reduced voluntary cough physiologic capacity to defend the airway, and a clinically distinguishable blunted motor response to reflex cough screening.

Current approaches to reporting pharyngo-laryngeal secretions

PURPOSE OF REVIEW

Accumulated secretions in the pharynx and larynx are associated with dysphagia, aspiration and pneumonia, as well as increased social, health and economic burden. This article reviews developments in the instrumental reporting of pharyngo-laryngeal secretions over the last 2 years.

RECENT FINDINGS

Although the healthy pharynx and larynx is moist, accumulation of secretions is indicative of abnormality. Using standardized secretion scales allows early identification, quantification of risk in patients, and sensitive monitoring of patients over time. Nonstandardized and subjective secretion reporting is common in recently published research despite the validation of a number of publicly available tools. Research characterizing accumulated secretions has contributed to our understanding of pathophysiology associated with poor secretion management and may inform future treatment studies.

SUMMARY

Routine and standardized reporting of secretions is critical for patient assessment and should be reported in the most standardized way possible. Further research investigating the clinical relevance and treatment of accumulated secretions relies on quantitative pharyngolaryngeal secretions reporting.