Swallowing dysfunction after mechanical ventilation in trauma patients

Background

Swallowing dysfunction can occur after mechanical ventilation, leading to complications such as aspiration and pneumonia. After mechanical ventilation, authors have recommended evaluating patients with contrast studies or endoscopy to identify patients at risk for swallowing dysfunction and aspiration. The purpose of the study was to determine if a bedside swallowing evaluation (BSE) can identify patients with swallowing dysfunction after mechanical ventilation.

Methods

This is a 1-year (2008) prospective study of all adult trauma patients admitted to the intensive care unit requiring mechanical ventilation. Upon separation from mechanical, all patients received a BSE. The BSE used mental status, facial symmetry, swallow reflex, and oral ice chips and water to identify swallowing dysfunction. Patients who passed the BSE were advanced to oral intake per physician orders, whereas patients who failed the BSE were allowed nothing by mouth.

Results

A total of 345 patients were included; 54 died before separation from mechanical ventilation and were excluded. The remaining 291 patients underwent BSE after separation from mechanical ventilation, with 143 (49%) passing and 148 (51%) failing. Patients who failed the BSE required mechanical ventilation longer than those who passed (14 ± 13 vs 5 ± 20 days, P = .001). In addition, only 23% of patients extubated within 72 hours failed the BSE, whereas 78% of those intubated more than 72 hours failed the BSE (P < .001). All patients who passed the BSE were discharged from the hospital without a clinical aspiration event. Independent risk factors for failure of BSE included tracheostomy, older age, prolonged mechanical ventilation, delirium tremens, traumatic brain injury, and spine fracture. Three (2%) patients who failed the BSE had a clinical aspiration event despite taking nothing by mouth.

Conclusions

A simple BSE can be used to identify patients at risk for swallowing dysfunction after mechanical ventilation. More importantly, BSE can safely clear patients without swallowing dysfunction, avoiding costly and time-consuming contrast studies or endoscopic evaluation.     

The Effect of Taste and Palatability on Lingual Swallowing Pressure

There is evidence that a strong, unpalatable, sour bolus improves swallowing in neurogenic dysphagia. It is not known whether other tastes may alter swallowing physiology. This study investigated the effect of moderate versus high taste concentrations (sweet, sour, salty, bitter) and barium taste samples on lingual swallowing pressure in ten healthy young adults, using a three-bulb lingual pressure array secured to the hard palate. Palatability of the samples was analyzed using the nine-point hedonic scale. Results showed that moderate sucrose, high salt, and high citric acid elicited significantly higher lingual swallowing pressures compared with the pressures generated by water. Pressures in the anterior bulb were significantly higher than those recorded from the middle or posterior bulb. There was no significant effect of palatability on lingual swallowing pressures. High salt and citric acid are known to elicit chemesthesis mediated by the trigeminal nerve. These results suggest that chemesthesis may play a crucial role in swallowing physiology. If true, dysphagia diet recommendations that include trigeminal irritants such as carbonation may be beneficial to individuals with dysphagia. However, before this recommendation more research is needed to examine how food properties and their perception affect swallowing in individuals with and without dysphagia.This research was supported by Syracuse University.     

The probability of correctly predicting subglottic penetration from clinical observations

It is difficult to predict from clinical signs and symptoms which patients suffer from subglottic penetration of foods. Most investigators attempting to predict aspiration have used small numbers of patients and relatively unsophisticated statistical techniques. In this study, we utilized 249 patients to examine the predictive value of several clinical factors thought to be suggestive of subglottic penetration with discriminant analysis. Using this approach we were able to correctly predict about 2/3 of both those who aspirate and those who do not aspirate. This is better than others have reported but still inadequate for clinical purposes.     

Laryngopharyngeal sensory deficits as a predictor of aspiration

OBJECTIVE: This study evaluates whether patients with severe sensory deficits in the hypopharynx are at increased risk for aspiration and determines the relationship between pharyngeal muscular weakness and hypopharyngeal sensory deficits. STUDY DESIGN AND SETTING: Forty patients with dysphagia who underwent flexible endoscopic evaluation of swallowing with sensory testing were prospectively divided into 2 groups. One group included patients with severe sensory deficits determined by an absent laryngeal adductor reflex and the other with normal sensitivity. Subjects were given liquid and puree consistencies and were evaluated for aspiration as well as pharyngeal muscle contraction. RESULTS: The differences in incidence of aspiration and pharyngeal muscular weakness between the 2 groups were significant (P < 0.001 Fisher's exact test). CONCLUSION: There is a strong association between motor function deficits and hypopharyngeal sensory deficits. SIGNIFICANCE: The association of sensory loss and motor deficits together with the use of flexible endoscopic evaluation of swallowing with sensory testing can predict those patients who are at highest risk for aspiration.     

Effects of the Removal of the Tracheotomy Tube on Swallowing During the Fiberoptic Endoscopic Exam of the Swallow (FEES)

This study investigated the effects, if any, that the presence of a tracheotomy tube has on the incidence of laryngeal penetration and aspiration in patients with a known or suspected dysphagia. This was a prospective, repeated-measure design study. A total of 37 consecutive patients with a tracheotomy tube underwent a fiberoptic endoscopic evaluation of swallowing (FEES). Patients were first provided with pureed food boluses with the tracheotomy tube in place. The tracheotomy tube was then removed and the tracheostoma site was covered with gauze and gentle hand pressure was applied. The patients were then evaluated without the tracheotomy tube in place with additional puree. Aspiration status was in agreement with and without the tracheotomy tube in place in 95% (35/37) of the patients. The two patients who demonstrated a different swallowing pattern with regard to aspiration demonstrated aspiration only when the tracheotomy tube was removed. Laryngeal penetration status was in agreement with and without the tracheotomy tube in place in 78% (29/37) of the patients. For the majority of the patients, the removal of the tracheotomy tube made no difference in the incidence of aspiration and/or laryngeal penetration. Results of this study do not support the clinical notion that the patient’s swallowing function will improve once the tracheotomy tube has been removed. Work for this project was completed at Marianjoy Rehabilitation Hospital, Wheaton, Illinois.     

SCIRehab Project Series: The Speech Language Pathology Taxonomy

Introduction: Outcomes research for speech language pathology (SLP) interventions for acute traumatic spinal cord injury (SCI) rehabilitation in the US is difficult because of the lack of a treatment classification system (taxonomy).

Objective: To describe a taxonomy developed by speech language pathologists (SLPs) to examine the effects of SLP interventions on SCI rehabilitation outcomes.

Methods: The SCIRehab study uses practice-based evidence, a rigorous observational methodology that examines treatment processes without specifying or requiring specific therapeutic interventions. Speech language pathology lead clinicians and researchers at 6 US SCI centers developed a detailed SLP taxonomy documentation process that is comprehensive of SLP interventions for patients with SCI.

Results: The SLP taxonomy consists of 7 intervention categories that address deficits (speech production for patients with artificial airway, motor speech and voice, swallowing, cognitive-communication, and communication) and the associated exercises and tasks that patients perform. Time is recorded for each category, and supplementary information focuses on cueing needs and family involvement that helps to describe and guide intervention selection. The SCIRehab project is enrolling 1,500 patients with acute traumatic SCI at 6 inpatient rehabilitation facilities.

Conclusions: Speech language pathology taxonomy information is being captured for the SCIRehab patients who are referred for SLP services; this may be the first attempt to document the many details of the SLP rehabilitation process for patients with SCI in the US.