SWALLOW PHYSIOLOGY IN PATIENTS WITH TRACH CUFF INFLATED OR DEFLATED: A RETROSPECTIVE STUDY

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1 SWALLOW PHYSIOLOGY IN PATIENTS WITH TRACH CUFF INFLATED OR DEFLATED: A RETROSPECTIVE STUDY Ruiying Ding, PhD, 1 Jeri A. Logemann, PhD 2 1 University of Wisconsin-Whitewater, Department of Communicative Disorders, 1022 Roseman Building, Whitewater, Wisconsin dingr@uww.edu 2 Northwestern University, Department of Communication Sciences and Disorders, Evanston, Illinois Accepted 24 March 2005 Published online 5 August 2005 in Wiley InterScience ( DOI: /hed Abstract: Background. Past research has suggested that medical diagnosis and trach cuff conditions may contribute to swallow physiology changes in patients with tracheostomy. This study attempts to investigate the differences in swallow physiology between patients with trach cuff-inflated and trach cuff deflated conditions with respect to four medical diagnostic categories: neuromuscular disorder, head and neck cancer, respiratory diseases, and general medical diagnosis. Methods. Retrospective database analysis of videofluoroscopic study results in 623 patients with tracheostomies with trach cuff-inflated or cuff deflated conditions. Swallow disorders were examined for each patient. Results. The frequencies of reduced laryngeal elevation and silent aspiration were found to be significantly higher in the cuffinflated condition than the cuff deflated condition. Significant swallow physiology changes were also found to be significantly different among various medical diagnostic categories. Conclusions. It is important to evaluate changes in swallow physiology under both the trach cuff-inflated and cuff deflated conditions to fully assess swallow function. A 2005 Wiley Periodicals, Inc. Head Neck 27: , 2005 Keywords: tracheostomy; cuff-inflated; cuff deflated; swallow physiology; dysphagia Correspondence to: R. Ding B 2005 Wiley Periodicals, Inc. Literature review has generated conflicting information on the effect of an inflated tracheostomy cuff. 1,2 A tracheostomy tube with a cuff may be placed to prevent aspiration of secretions, aspiration of food, and aspiration of gastric contents. By pressing against the tracheal wall, the cuff can impede the flow of pharyngeal secretions into the airway below the cuff. However, this belief has been refuted by clinical experience and in the literature. 1,2 An inflated cuff is not absolutely protective of the airway, and stagnant secretions collecting above the cuff can trickle down past the cuff, potentially leading to infection. Increasing the tracheal cuff pressure may only serve to increase the drag on the larynx, because it elevates during the swallow or causes pressure necrosis, which may lead to tracheal wall damage such as malacia, stenosis, or fistula. 3,4 In addition, the cuff also blocks expiratory airflow through the larynx, thereby obviating both phonation and airway clearance, as well as desensitizing the larynx. 5,6 It is important to investigate the differences in swallow physiology changes in patients with dysphagia with cuff deflated and cuff inflated to guide our use of cuff inflation in the clinical management of patients with dysphagia. Swallow Physiology with Trach Cuff Inflated or Deflated HEAD & NECK September

2 No studies have investigated changes in swallow physiology between cuff-inflated and cuff deflated conditions. This study attempted to investigate the differences in swallow physiology between patients with trach cuff-inflated and trach cuff deflated conditions with respect to four medical diagnostic categories: neuromuscular disorders, head and neck cancer, respiratory diseases, and general medical diagnosis. Certain medical diagnoses such as stroke or head and neck cancer may predispose patients to swallowing disorders with or without inflated trach cuffs. Stroke, 7 poliomyelitis, 8 and Parkinson s disease 9 are all associated with an increased incidence of swallowing dysfunction. Patients with head and neck cancer were also reported to demonstrate significant swallowing difficulty with or without tracheostomies. 10 It is possible that in some of the patients with an underlying neuromuscular disease, swallowing abnormalities were primarily related to the medical condition, rather than the inflated trach cuff. The results of this study will guide us in future management of patients with dysphagia. PATIENTS AND METHODS Subjects. The format of the study was a retrospective database analysis of patients with tracheostomies with either the trach cuff inflated or deflated, who underwent videofluoroscopic studies between 1989 and There were a total of 623 patients in the study. Procedures. All patients with tracheostomies who underwent videofluoroscopic studies between 1989 and 2003 were included in the analysis. The average age of the 623 patients was 52 F 19 years. There were 439 men and 184 women in the study. The following information was collected from the database: patient age, sex, medical diagnosis, cuff condition (deflated/inflated), and videofluoroscopic study findings (nature of swallow disorders). A logistic regression analysis was performed with swallow physiology as the outcome measure and cuff condition and medical diagnosis as the predictors. Analysis was performed with SPSS NOMREG. The outcome measures of swallow physiology included the following: delayed oral initiation, reduced tongue manipulation and control, reduced tongue strength, slow oral transit, reduced chew, delayed pharyngeal triggering, reduced tongue base retraction, reduced laryngeal elevation, reduced laryngeal closure, reduced cricopharyngeal opening, aspiration before the swallow, aspiration during the swallow, aspiration after the swallow, and silent aspiration. Five swallow physiology disorders (reduced lip closure, reduced pharyngeal strength, slowed pharyngeal transit, reduced velopharyngeal closure, and absent pharyngeal swallow) were excluded from the statistical analysis because of very small frequencies in each category. The two predictors were cuff condition and medical diagnosis. Cuff conditions included cuff deflated and cuff-inflated conditions. The medical diagnosis included the following four categories: (1) neuromuscular disorders such as stroke and Parkinson s disease, (2) head and neck cancer, (3) respiratory diseases such as chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS), and (4) general medical diagnosis such as kidney cancer and knee surgery. A total of 342 patients had their cuff inflated, whereas 281 patients had their cuff deflated. Of the 623 patients, 228 patients had a medical diagnosis of neuromuscular disorder, 102 patients had been treated for head and neck cancer, 65 patients had a medical diagnosis of respiratory disease, and 228 patients had a general medical diagnosis. We used a criterion a =.0036 (to compensate for inflated type I error rate with 14 dependent variable). RESULTS A logistic regression analysis was performed through SPSS NOMREG to assess prediction of the presence of swallow physiology abnormalities on the basis of medical diagnosis and cuff condition. Data from 623 patients were available for analysis. There was a good model fit (discrimination among groups) on the basis of medical diagnosis and cuff condition (chi-square from to 3.857, p from.277 to.991 using a deviance criterion). No significant interaction was found between the medical diagnosis and cuff condition with all the outcome measures (Table 1). Subsequently, chi-square tests were used to analyze the frequencies of abnormalities in swallow physiology between cuff-inflated and cuff deflated conditions. The results are reported in Table 2. The frequencies of reduced laryngeal elevation and silent aspiration were the only two swallow physiology changes that were significant between the cuff-inflated and cuff deflated conditions. The frequencies of reduced laryngeal elevation and 810 Swallow Physiology with Trach Cuff Inflated or Deflated HEAD & NECK September 2005

3 Table 1. The probability of interaction effect between medical diagnosis and cuff condition. Probability of interaction effect between medical diagnosis and cuff Swallow disorders condition Delayed oral onset.979 Reduced tongue manipulation.761 Reduced tongue strength.423 Reduced chew.277 Slow oral transit.961 Delayed pharyngeal triggering.736 Reduced tongue base retraction.026 Reduced laryngeal elevation.991 Reduced laryngeal closure.508 Reduced cricopharyngeal opening.440 Aspiration before swallow.677 Aspiration during swallow.681 Aspiration after swallow.388 Silent aspiration.364 Table 2. Frequencies of significant changes in swallow physiology between cuff-inflated and cuff deflated conditions. Swallow physiology changes Cuff inflated Cuff deflated Probability Delayed oral initiation Reduced tongue manipulation Reduced tongue strength Slow oral transit Reduced chew Delayed pharyngeal triggering Reduced tongue base retraction Reduced laryngeal elevation <.001* Reduced laryngeal closure Reduced cricopharyngeal opening Aspiration before swallow Aspiration during swallow Aspiration after swallow Silent aspiration <.001* *Significant frequencies. silent aspiration were significantly greater in patients with the cuff inflated than in patients in whom the cuff was deflated. Chi-square tests were used to analyze the frequencies of swallow abnormalities among the four medical diagnostic categories, and the results are reported in Table 3. Medical diagnosis was shown to be significant for several swallow physiology changes: reduced tongue manipulation, slow oral transit, delayed pharyngeal triggering, reduced laryngeal closure, aspiration during swallow, and aspiration after swallow. Follow-up Mann Whitney tests were used to analyze the differences in frequencies of various swallow abnormalities in three medical diagnosis categories: neuromuscular disorders, head and neck cancer, and respiratory diseases compared with the general medical diagnosis category. The significant differences in swallow physiology by group are reported in Table 4. Compared with the general medical diagnosis, the diagnosis of neuromuscular disorders seemed to show significantly greater frequencies of reduced oral tongue manipulation, slow oral transit, delayed pharyngeal triggering, and aspiration after swallow, whereas the diagnosis of head and neck cancer seemed to show significantly higher frequencies of reduced laryngeal Swallow physiology changes Table 3. Frequencies of swallow physiology changes among four categories of medical diagnosis. Neuromuscular disorders Head and neck cancers Respiratory diseases General medical diagnosis p value Delayed oral initiation Reduced tongue manipulation * Reduced tongue strength Slow oral transit <.001* Reduced chew Delayed pharyngeal triggering <.001* Reduced tongue base retraction Reduced laryngeal elevation Reduced laryngeal closure * Reduced cricopharyngeal opening Aspiration before swallow Aspiration during swallow <.001* Aspiration after swallow <.001* Silent aspiration *Significant frequencies. Swallow Physiology with Trach Cuff Inflated or Deflated HEAD & NECK September

4 Table 4. Significant swallow physiology changes in three medical diagnosis categories (neuromuscular disorder, head and neck cancer, and respiratory diseases) compared with the general medical diagnosis category. Swallow physiology changes Medical diagnosis Probabilty Reduced tongue Neuromuscular disorder.001 manipulation Slow oral transit Neuromuscular disorder <.001 Delayed pharyngeal Neuromuscular disorder <.001 triggering Aspiration after swallow Neuromuscular disorder <.001 Aspiration after swallow Head and neck cancer <.001 Reduced laryngeal Head and neck cancer <.001 closure Aspiration during swallow Head and neck cancer <.001 closure, aspiration during swallow, and aspiration after swallow. In all patients with a tracheotomy, including trach cuff-inflated and trach cuff deflated conditions, the frequency of aspiration was 64.8%. The frequency of silent aspiration for all tracheostomy patients was 29.9%. DISCUSSION Compared with the trach cuff deflated condition, an inflated cuff may further anchor the larynx to the anterior neck. 6 Therefore, it is not surprising that we observed a significantly greater frequency of reduced laryngeal elevation in patients with the cuff inflated than in those with the cuff deflated. An inflated cuff in tracheostomy has also been shown to block the expiratory air flow through the larynx and desensitize the larynx and pharynx. 5,6 Subsequently, the patient may be unaware of aspiration, and the protective cough mechanism that would ordinarily clear the airway may be blunted. It seems that reduced laryngeal sensation may contribute to the lack of sensation of aspirated material, hence silent aspiration. A significantly higher frequency of silent aspiration in patients with the cuff inflated seems to support this theory. The results of this study are consistent with previous studies 6,10,11 on this topic. This study is limited to describing the frequency and characteristics of swallowing physiology in patients with tracheostomy who completed videofluoroscopic studies. Caution should be exercised in generalizing our results. It is likely that patients who were referred for videofluoroscopic study had already shown clinical signs of swallowing disorders or had been suspected of having swallowing disorders. The swallowing physiology changes we observed in patients with an inflated cuff may be more related to severe illness that requires ventilation or agents used to treat critically ill patients than the presence of an inflated trach cuff. We found significant abnormalities in oral and pharyngeal phase swallow physiology among various medical diagnostic categories in tracheostomy patients. In this study, the general medical diagnosis category is used as a control group, because the diagnosis itself should not cause any specific swallowing physiology changes. It is safe to assume that the swallowing physiology abnormalities in this group are primarily due to the presence of tracheostomy or general fatigue. Greater frequencies of delayed pharyngeal triggering, reduced tongue base retraction, and reduced laryngeal elevation were found to be associated with the general medical diagnosis. The findings from this study are consistent with previous studies findings. Compared with the general medical diagnosis category, the diagnosis of neuromuscular disorders showed significantly greater frequencies of reduced tongue manipulation, slow oral transit, delayed pharyngeal triggering, and aspiration after swallowing, whereas the diagnosis of head and neck cancer showed significantly greater frequencies of reduced laryngeal closure, aspiration during swallowing, and aspiration after swallowing. All these abnormalities in swallowing physiology are presumably due to the medical diagnoses of neuromuscular disorders or head and neck cancer. Previous studies investigating swallowing physiology changes in stroke, 7 Parkinson s disease, 9 and head and neck cancers 10,14 have had similar findings. When combined across both the cuff-inflated and cuff deflated conditions, the incidence of aspiration in this study is 64.8%. This corresponded well with previously reported 50% to 87% in patients with tracheostomies. 4,12,13 Previous studies have reported a 77% to 82% silent aspiration rate in patients who aspirated. 13,16 In our study, 46.2% of aspirators were silent aspirators (ie, approximately half of the aspirators in our study did not cough at the time of aspiration). These data correspond well with a previous study investigating silent aspiration in an acute care setting. 16 The lack of reaction to aspiration may 812 Swallow Physiology with Trach Cuff Inflated or Deflated HEAD & NECK September 2005

5 be due to decreased laryngeal sensation caused by inflated tracheostomy cuffs. We have found a greater incidence of silent aspiration and reduced laryngeal elevation in the trach cuff-inflated condition than in the trach cuff deflated condition in the 623 patients with tracheostomies. The results of this study emphasize the importance of completing diagnostic studies of swallowing physiology with a tracheostomy, preferably with the trach cuff inflated and deflated. REFERENCES 1. Higgins DM, Maclean JCF. Dysphagia in the patient with a tracheostomy: six cases of inappropriate cuff deflation or removal. Heart Lung 1997;26: Naito Y, Mima H, Itaya T, Yamazaki K, Kato H. Continuous oxygen insufflation using a speaking tracheostomy tube is effective in preventing aspiration during feeding. Anesthesiology 1996;84: Nash M. Swallowing problems in the tracheostomized patient. Otol Clin North Am 1988;21: Goldsmith T. Evaluation and treatment of swallowing disorders following endotracheal intubation and tracheostomy. Int Anesthesiol Clin 2000;38: Siebens AA, Tippett DC, Kirby N, French J. Dysphagia and expiratory air flow. Dysphagia 1993;8: Feldman SA, Deal CW, Urguhart W. Disturbance of swallowing after tracheostomy. Lancet 1996;1: Horner J, Massey MD, Riski JE. Aspiration following stroke: clinical correlates and outcome. Neurology 1988;38: Sonies BC, Dalakas MC. Dysphagia in patients with the postpolio syndrome. N Engl J Med 1991;324: Walton J. The parkinsonian syndrome. In: Walton J, (editor). Brain s diseases of the nervous system. London: Oxford University Press; p Logemann JA. Evaluation and treatment of swallowing disorders. 2nd ed. Austin TX: Pro-Ed; Abraham SS, Wolf EL. Swallowing physiology of toddlers with long-term tracheostomies: a preliminary study. Dysphagia 2000;15: Tolep K, Getch CL, Criner GJ. Swallowing dysfunction in patients receiving prolonged mechanical ventilation. Chest 1996;109: Elpern E, Scott M, Petro L, Ries M. Pulmonary aspiration in mechanically ventilated patients with tracheostomies. Chest 1994;105: Kronenberger MB, Meyers AD. Dysphagia following head and neck cancer surgery. Dysphagia 1994;9: Leder S. Incidence and type of aspiration in acute care patients requiring mechanical ventilation via a new tracheostomy. Chest 2002;122: Smith CH, Logemann JA, Colangelo LA, Rademaker AW, Pauloski BR. Incidence and patient characteristics associated with silent aspiration in the acute care setting. Dysphagia 1999;14:1 7. Swallow Physiology with Trach Cuff Inflated or Deflated HEAD & NECK September