Dysphagia
The children with tracheostomy may be fed by oral route and/or by tube, depending on underlying conditions and swallowing abilities. Mainly, the severity and characteristics of neurological impairment are determinative of feeding route. For instance, the lack or diminished gag reflex, the disorders with bulbar involvement require tube feeding. Factors that may affect feeding of the children with tracheostomy are given in Table 8 33,52.
Swallowing is a complex process which is controlled by brain stem, cortex and enteric nervous system that innervates esophagus smooth muscles. There are three phases of swallowing. The oral phase begins with opening of the mouth and continues with sucking, biting, chewing. The tongue movements and addition of the saliva allow the food bolus to pass into oropharynx. In pharyngeal phase, the velum elevates to close the nasopharynx. The hyoid and larynx elevate with anterior moving, epiglottis descends and vocal cords are closed. The laryngeal elevation protects the airway and anterior movement of the larynx helps open the upper esophageal sphincter. The contraction of the pharyngeal muscles moves the bolus from the pharynx to the esophagus. In esophageal phase, bolus passes into the stomach by esophagus peristaltism, gravity and LES relaxation53. The effect of tracheostomy tube on increasing the risk of aspiration and penetration is defined but there is no strong evidence. Tracheostomy tube fixes the larynx and prevents laryngeal elevation. Also it desensitizes larynx and leads an ineffective cough mechanism, because a positive subglottic pressure cannot be maintained during swallowing. The cuff of the tracheostomy tube may impringe on the esophagus during deglutition8,53. Streppel M et al54. reported 70% of the children with tracheostomy had swallowing disorders. The aspiration rate in the study group was 43% and half of them had silent aspiration. The underlying diseases may also contribute to the development of swallowing disorders54.
The aspiration, penetration and other swallowing problems can be detected by various diagnostic approaches. Penetration is passage of material into the laryngeal lumen, but remaining above the vocal cords, not passing to the glottis. Aspiration is the passage of material below the vocal cords. The Modified Blue Dye Test is a screening test for aspiration. After the patient swallow a methylene blue mixed drink or food, suctioning a colored secretion is considered as aspiration. Flexible Endoscopic Evaluation of Swallowing (FEES) and Videofluoroscopy (VFS) are the gold standart methods to evaluate swallowing dysfunction33,53,54. Pharyngeal phase of swallowing, penetration and aspiration can be detected by FEES. A speech and language therapist (SLT) and a pediatric Ear-Nose-Throat (ENT) specialist can perform FEES. A VFS demonstrate oral, pharyngeal and esophageal phases of swallowing, penetration, aspiration, obstruction, fistulas and motility problems can be observed. VFS is usually performed by a SLT and a radiologist. In the suspicion of an abnormality in the esophageal phase of swallowing, manometry may be considered. Swallowing the different consistencies of foods such as liquids, thickened liquids, purees and solids can be determined 33,53,54.
Aspiration is a major problem that complicates the clinical status and respiratory condition of these children. Aspiration may lead hypoxemia, cough, respiratory distress or it may be silent. Untreated aspiration may result in bronchiectasis and decreased lung function33. On contrary, in recent years many centers change their feeding strategy to giving heavy-thickened liquids even if there is aspiration and/or penetration on VFSS. Particularly in patients with tracheostomy it is considered to be safer due to the chance of removing aspirates through the tracheostomy tube. Furthermore, improvement of the swallowing function depending on oral stimulation over time is possible55,56.
In the first 2-4 months of life, swallowing and sucking are reflexive, subsequently swallowing becomes more voluntary and it progressively develops in the first years of life. The development of proper oral feeding skills is negatively affected in premature infants who had long term intubation in intensive care units. Oral-motor and sensory feeding difficulties such as weak or incoordinate suck and swallow, oral aversion, hypersensitivity to oral stimuli (may be due to repetitive aspirations), refusal to taste food may occur32,53,54.
The early experience of oral feeding in tube fed children will be beneficial as follows; facilitates the oral motor skills such as chewing and swallowing, improves sensory skills such as taste and texture of the foods, and reduces oral aversion. A team work should be required to decide and carry out to transit oral feeding in tube-feeding children with tracheostomy. The team should be consist of an occupational therapist, speech language pathologist, physical therapist, respiratory therapist, psychologist, dietitian and clinicians as pediatric pulmonologist, pediatric ear-nose-throat specialist and pediatric gastroenterologist32,53,54.
Following the instrumental tests, the patients who have a medical stability, swallow their oral secretions, need infrequent tracheal suctioning are seem to be ready to oral feeding. Oral feeding should be attempted under the actual mode of ventilation with following oxygen saturation. The aspiration and oral aversion risk may be reduced by tasting small amounts of food in extreme caution. Coughing, chocking, increased oxygen demand or worsening pulmonary functions, presence or suctioning of food or liquid around the stoma or in the tracheostomy tube, sudden changes in the amount, constituency or color of the secretions are significant findings of unsuccessful swallowing32,55.