Risk Factors for Aspiration Pneumonia After Receiving Liquid-Thickening Recommendations

Objective We examined the influence of liquid thickness levels on the frequency of liquid penetration-aspiration in patients with dysphagia and evaluated the clinical risk factors for penetration-aspiration and aspiration pneumonia development. Study Design A case series. Setting Single-institution academic center. Methods We reviewed medical charts from 2018 to 2019. First, we evaluated whether liquid thickness levels influence the frequency of liquid penetration-aspiration in patients with dysphagia. Penetration-aspiration occurrence in a videofluoroscopic swallowing study was defined as Penetration-Aspiration Scale (PAS) scores ≥3. Second, the association between liquid thickness level and penetration-aspiration was analyzed, and clinical risk factors were identified. Moreover, clinical risk factors for aspiration pneumonia development within 6 months were investigated. Results Of 483 patients, 159 showed penetration-aspiration. The thickening of liquids significantly decreased the incidence of penetration-aspiration ( P < .001). Clinical risk factors for penetration-aspiration were vocal fold paralysis (odds ratio [OR], 1.99), impaired laryngeal sensation (OR, 5.01), and a history of pneumonia (OR, 2.90). Twenty-three patients developed aspiration pneumonia while undertaking advised dietary changes, including liquid thickening. Significant risk factors for aspiration pneumonia development were poor performance status (OR, 1.85), PAS score ≥3 (OR, 4.03), and a history of aspiration pneumonia (OR, 7.00). Conclusion Thickening of liquids can reduce the incidence of penetration-aspiration. Vocal fold paralysis, impaired laryngeal sensation, and history of aspiration pneumonia are significant risk factors of penetration-aspiration. Poor performance status, PAS score ≥3, and history of aspiration pneumonia are significantly associated with aspiration pneumonia development following recommendations on thickening liquids. Level of Evidence 3.

Inter- and Intra-Rater Reliability of Laryngeal Sensation Testing with the Touch Method During Flexible Endoscopic Evaluations of Swallowing

Objectives: Sensation is an integral component of laryngeal control for breathing, swallowing, and vocalization. Laryngeal sensation is assessed by elicitation of the laryngeal adductor reflex (LAR), a brainstem-mediated adduction of the true vocal folds. During Flexible Endoscopic Evaluations of Swallowing (FEES), the touch method can be used to elicit the LAR to judge laryngeal sensation. Despite the prevalence of this method in clinical practice and research, prior studies have yet to examine inter- and intra-rater reliability. Methods: Four speech-language pathologists rated 125 randomized video clips for the presence, absence, or inability to rate the LAR. Fifty percent of video clips were re-randomized and re-rated 1 week later. Raters then created guidelines and participated in formal consensus training sessions on a separate set of videos. Ratings were repeated post-training. Results: Overall inter-rater reliability was fair (κ = 0.22) prior to training. Pre-training intra-rater reliability ranged from fair (κ = 0.35) to almost perfect (κ = 0.89). Inter-rater reliability significantly improved after training (κ = 0.42, P < .001), though agreement did not reach prespecified acceptable levels (κ ≥ 0.80). Post-training intra-rater reliability ranged from moderate (κ = 0.49) to almost perfect (κ = 0.85). Conclusion: Adequate inter-rater reliability was not achieved when rating isolated attempts to elicit the LAR. Acceptable within-rater reliability was observed in some raters 1 week after initial ratings, suggesting that ratings may remain consistent within raters over a short period of time. Limitations and considerations for future research using the touch method are discussed.

Long-term Swallowing Function, Pulmonary Complications, and Quality of Life after Supracricoid Laryngectomy

Objectives Long-term effects of supracricoid laryngectomies are nowadays under discussion. The purpose of this study was to detect the prevalence of chronic aspiration and incidence of pulmonary complications, to investigate possible influencing factors, and to analyze dysphagia-related quality of life in a cohort of patients who recovered swallowing function after undergoing supracricoid laryngectomies. Study Design Retrospective observational study. Setting San Raffaele Hospital, Vita-Salute University, Milan, Italy. Methods A cohort of 39 patients who recovered swallowing function free of disease after a minimum 3-year follow-up period was retrospectively investigated between October and December 2017—clinically with the Pearson’s Scale and M. D. Anderson Dysphagia Inventory and instrumentally with fiberoptic endoscopic evaluation of swallowing. Results Chronic aspiration was demonstrated in a significant portion of patients (clinically in 33.3% and instrumentally in 35.9%). Aspiration was influenced by advanced age at surgery ( P = .020). Type of surgical procedure, resection of 1 arytenoid cartilage, postoperative rehabilitation with a speech-language therapist, radiotherapy, age at consultation, and length of follow-up did not influence the prevalence of aspiration. Pulmonary complications affected 5 patients; incidence of pulmonary complications was related to aspiration and was favored by poor laryngeal sensation/cough reflex. Aspiration significantly affected quality of life. Conclusions Chronic aspiration is frequent and affects patients’ quality of life. However, incidence of pulmonary complications is low; therefore, oral feeding should not be contraindicated for aspirating patients. Preservation of laryngeal sensation and cough reflex is mandatory to prevent pulmonary complications.

Variability of the Pressure Measurements Exerted by the Tip of Laryngoscope During Laryngeal Sensory Testing: A Clinical Demonstration

Purpose Clinicians often test laryngeal sensation by touching the laryngeal mucosa with the tip of a flexible laryngoscope. However, the pressure applied to the larynx by using this touch method is unknown, and the expected responses elicited by this method are uncertain. The variability in pressure delivered by clinicians using the touch method was investigated, and the subject responses to the touches were also reported. Methods A fiberoptic pressure sensor passed through the working channel of a laryngoscope, with its tip positioned at the distal port of the channel. Two examiners each tested 8 healthy adults. Each examiner touched the mucosa covering the left arytenoid 3 times. The sensor recorded the pressure exerted by each touch. An investigator noted subject responses to the touches. From the recorded videos, the absence or presence of the laryngeal adductor reflex in response to touch was judged. Results Pressure values obtained for 46 of the 48 possible samples ranged from 17.9 mmHg to the measurement ceiling of 350.0 mmHg. The most frequently observed response was positive subject report followed by the laryngeal adductor reflex. Conclusion Pressure applied to the larynx by using the touch method was highly variable, indicating potential diagnostic inaccuracy in determining laryngeal sensory function.

Central nervous system integration of sensorimotor signals in oral and pharyngeal structures: oropharyngeal kinematics response to recurrent laryngeal nerve lesion

Safe, efficient liquid feeding in infant mammals requires the central coordination of oropharyngeal structures innervated by multiple cranial and spinal nerves. The importance of laryngeal sensation and central sensorimotor integration in this system is poorly understood. Recurrent laryngeal nerve lesion (RLN) results in increased aspiration, though the mechanism for this is unclear. This study aimed to determine the effect of unilateral RLN lesion on the motor coordination of infant liquid feeding. We hypothesized that 1) RLN lesion results in modified swallow kinematics, 2) postlesion oropharyngeal kinematics of unsafe swallows differ from those of safe swallows, and 3) nonswallowing phases of the feeding cycle show changed kinematics postlesion. We implanted radio opaque markers in infant pigs and filmed them pre- and postlesion with high-speed videofluoroscopy. Markers locations were digitized, and swallows were assessed for airway protection. RLN lesion resulted in modified kinematics of the tongue relative to the epiglottis in safe swallows. In lesioned animals, safe swallow kinematics differed from unsafe swallows. Unsafe swallow postlesion kinematics resembled prelesion safe swallows. The movement of the tongue was reduced in oral transport postlesion. Between different regions of the tongue, response to lesion was similar, and relative timing within the tongue was unchanged. RLN lesion has a pervasive effect on infant feeding kinematics, related to the efficiency of airway protection. The timing of tongue and hyolaryngeal kinematics in swallows is a crucial locus for swallow disruption. Laryngeal sensation is essential for the central coordination in feeding of oropharyngeal structures receiving motor inputs from different cranial nerves.