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Dr. Gallivan is Assistant Professor of Clinical Surgery, The University of Massachusetts Medical School, and Thoracic, Airway and Voice Surgeon, Mercy Medical Center.
Correspondence to: Gregory J. Gallivan, MD, FCCP, 299 Carew St, Suite 404, Springfield, MA 01104-2361; e-mail: singingsurgeon{at}attbi.com
The use of videolaryngoscopic recording techniques to examine the larynges of patients in the critical care setting, during and after endotracheal intubation and extubation, was reported in 1989 and 1990.1 2 Videotape recording of endoscopies objectively discovers and documents details that cannot be appreciated by the unaided eye in real-time. Videotape recording optimizes and establishes archives of the procedures.
In this issue of CHEST (see page 1721), Leder presents aspiration in acute care patients requiring mechanical ventilation via a new tracheotomy. The study investigates the incidence and type of aspiration, overt or silent. A new tracheotomy is defined as one done < 2 months before examination. Leder defines aspiration as evidence of material below the level of the vocal folds, with silent aspiration defined as occurring in a patient who had no overt symptoms of aspiration (coughing or choking). Two thirds of patients requiring short-term mechanical ventilation via a new tracheotomy swallowed successfully. When aspiration occurred, it was predominantly silent. The timing of determining swallowing success in patients < 70 years old and > 70 years old was postulated. The author cites references indicating his own experience in fiberoptic endoscopic documentation of the high incidence of aspiration in critical care patients of varying ages. Leder’s technique avoided topical anesthesia, thereby eliminating any potential adverse anesthetic reactions and ensuring a reliable physiologic evaluation—an important point. Advantages of fiberoptic endoscopic evaluation of swallowing (FEES) over modified barium swallow (MBS) in patients requiring mechanical ventilation and tracheotomy were cited.
Unfortunately, videotape recording was not used with any of the procedures. It was stated that since real-time FEES has been shown to be very reliable in identifying aspiration, videotape recordings were not made. The reference cited was that of Langmore and coworkers,3 who historically coined the term fiberoptic endoscopic evaluation of swallowing safety as a new procedure in 1986 and reported results in 1988. In that article, Dr. Langmore and colleagues assessed the pharyngeal stage of swallowing in patients with dysphagia. They found that usually no anesthesia was needed for the procedure, and they pointed out that others had noted a reduction in both the urge and ability to swallow following the application of lidocaine in the pharynx. The actual dynamics of the swallow were difficult to assess because the tumultuous upheaval of the larynx and pharynx temporarily obscured any view. However, aspiration before the swallow, secondary to premature spillage into the hypopharynx and aspiration after the swallow, secondary to pharyngeal residue, was observed. The approximate quality and location of aspiration that occurred during the swallow could usually be identified immediately after the swallow by residue remaining in the airway.
Also cited by Dr. Leder is the study by Langmore et al4 reported in 1991, comparing endoscopic and videofluoroscopic evaluations of swallowing and aspiration. They defined laryngeal penetration as material spilling into the laryngeal vestibule, but not passing below the vocal folds. They defined aspiration as material falling below the glottis, which was observed either directly as the bolus fell between abducted vocal folds or after the swallow, as the bolus rested on what they called the subglottic "shelf"—the mucous membrane covering the lower part of the thyroid and cricoid cartilage, just below the anterior commissure. Alternatively, aspiration could be observed as the patient coughed and expectorated the green dyed bolus material that had been aspirated. Unfortunately, neither Dr. Leder nor Dr. Langmore and colleagues addressed passing the transnasal endoscope across the glottis into the upper trachea, passing the endoscope via the cricopharyngeal opening into the proximal esophagus, or passing the flexible scope via an established tracheostoma to visualize both tracheobronchoscopic and subglottic anatomic structures. Also not cited, in those patients who had a tracheotomy tube in place, was whether the tracheotomy cuff was deflated or inflated during the act of deglutition.
As media and computer technology has evolved during the past decade, videoendoscopy assessment techniques have improved. By 1992, Dr. Langmore had incorporated the videotape recorder into her routine equipment.5 In 1993, Dr. Langmore presented her videotape recording techniques and included the American Speech-Language-Hearing Association criteria for FEES that, in part, stated "the study can be videotaped to optimize clinical use and interpretation."6 7
In 1994, Kidder et al8 compared the indications and techniques of endoscopy in evaluation of cervical dysphagia with radiographic techniques. Endoscopy was the preferred tool for assessment, so that the examiner could directly assess laryngeal function for adduction airway protection in relation to bolus flow. If the vocal folds did not adduct by the time bolus fell to their level, aspiration was seen. If the bolus spilled into the laryngeal vestibule, the exact point of entry could be ascertained. The different patterns of aspiration could lead to the use of appropriate therapeutic positioning maneuvers, to lessen the chance of penetration and aspiration. If the vocal folds were not adducted during spillage, the patient might be taught to assume this protective maneuver while trying to initiate the swallow. If impaired sensation were found, the patient could be taught to use a protective airway closure maneuver when swallowing and not rely on subjective perception of whether material was in the hypopharynx. Kidder et al8 concurred that recording the examination on videotape was important. Kidder et al8 emphasized that frame-by-frame and slow-motion analysis of videofluoroscopy have led to the realization that oral, pharyngeal, laryngeal, and esophageal physiologic components of normal swallowing overlap in a somewhat predictable fashion in relation to various bolus volumes and viscosities. These principles apply today to videotape-recorded endoscopic evaluation of swallowing.
By 1995, Langmore and Hicks9 standardized FEES equipment needs, including a flexible fiberoptic endoscope, an endoscopic video camera, light source, videotape recorder, color monitor, time character generator, and a video printer. Recording on videotape ensures repeatability to gauge progress in recovery of swallow function and removes the subjectivity of the examiner who is making the evaluations in real-time while doing the procedure. The distinct advantage of initially doing the procedure and later meticulously reviewing the videotape recording, specifically with slow motion and frame-by-frame forward and reverse-motion analysis, captures more than the human eye can perceive in real-time.
Aviv and colleagues10 in 1998 introduced an office or bedside method of evaluating both the motor and sensory components of swallowing, called fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST). FEESST combined the established endoscopic evaluation of swallowing with a technique that determined laryngopharyngeal sensory discrimination thresholds by endoscopically delivering air-pulse stimuli to the mucosa innervated by the superior laryngeal nerves. Laryngopharyngeal sensory capacity was determined by elicitation of the laryngeal adductor reflex, a sensory-motor reflex. FEESST allowed the clinician to obtain a comprehensive bedside assessment of swallowing that was performed as the initial swallowing evaluation for the patient with dysphagia.
In 2000, Aviv11 addressed the fact that aspiration pneumonia is a significant cause of morbidity and mortality in both acute and long-term care settings. The purpose of his study was to provide an initial investigation of whether FEESST or the MBS test was superior as the diagnostic test for evaluating and guiding the behavioral and dietary management of outpatients with dysphagia. He concluded that whether or not dysphagic patients had their dietary and behavioral management guided by the results of FEESST or of MBS, their outcomes with respect to pneumonia incidence and pneumonia-free interval were essentially the same. The equipment utilized to perform laryngopharyngeal sensory discrimination testing included an endoscope, a light source, a sensory stimulator that was attached to the endoscope, a television monitor, a camera, a video printer, and a videocassette recorder (VCR). He utilized no local anesthesia. Comprehensive diagnostic studies of deglutition were very useful in providing the clinician with detailed information that could serve as a precise guide to implementation of changes in volume and consistency of food administration, as well as the postural maneuvers necessary to ensure a safe swallow.11
In 2001, Aviv and coworkers12 published a prospective study and found that FEESST was more cost-effective than MBS for the inpatient management of dysphagia in patients with head and neck cancer. In 2002, Aviv and coworkers13 reported that the absence of the laryngeal adductor reflex and impaired pharyngeal squeeze (pharyngeal muscular contraction) put patients with dysphagia at high risk for laryngeal penetration and aspiration compared with patients with an intact laryngeal adductor reflex and intact pharyngeal squeeze. A strong association between motor and sensory deficits in the laryngopharynx was found. Videotape recording techniques were intrinsic to the successful accomplishment of this study,13 and have been routinely used at the Unité de la Voix, Parole, Déglutition in Paris, France (Lise Crevier-Buchman, MD, PhD; personal communication; April, 2002).
In the patient who is a gross aspirator, real-time examination may suffice. However, to find the subtle aspirator patient, frame-by-frame analysis of a videotape recording is required. In addition, tracheoscopy is a valuable adjunct to FEES/FEESST. Videotape recording is required to determine airway protective reflexes; discovery and discernment of other lesions of the supraglottis, glottis, and subglottis; discovery of vocal movement disorders; determination of etiology; documentation of structural abnormalities; and elicitation of sensory disorders (Jonathan E. Aviv, MD; personal communication; May, 2002).
If one adds a digital three-chip camera and a digital VCR, or fully computerized digital equipment, detailed, precise frame-by-frame and slow-motion images reveal subtle elements of pathology of phonation and deglutition that cannot be appreciated by the human eye in real-time evaluations. The human eye can perceive just five different images per second. The National Television Systems Committee video format used in the United States allows 30 frames per second to be studied. With digital techniques, each frame identifies sharp, clear images of the vocal fold edge and fine details of laryngeal activity, including mucosal abnormalities and opening and closing patterns. Shape, movement, vibratory patterns, time relationships between opening and closing of vocal folds, and maximum opening and closure of vocal folds are observed. Routine use of videotape recording is required for documentation of changes resulting from treatment; enhancement of teaching to patients, families, professionals, and students; archival record keeping; a means for more than one specialist to view the procedure at the same time; a means for repeated observation of the same event repeatedly and definitively; quantitative and qualitative visual explanations of the data and disorders; and a means for visual feedback training. FEES without videotape recording relies on subjective interpretation and documentation, thereby diminishing the validity and reliability of conclusions. All sports fans know that the instant replay has revolutionized the way that we watch sports and the way in which they are judged. Should anything less precise be offered to our patients? Within the next year or two, inclusion of videotape recording for FEES, FEESST and strobovideolaryngoscopy procedures will be mandated by the Center for Medicare and Medicaid Services.
Acknowledgements
The author thanks Laurie H. Dagesse for assistance with manuscript preparation and Helen K. Gallivan, RN for assistance in research and editing.
References
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