Memorie M. Gosa

Pediatric Dysphagia: Physiology, Assessment, and Management

Infancy and childhood represent a time of unparalleled physical growth and cognitive development. In order for infants and children to reach their linear and neurological growth potential, they must be able to reliably and safely consume sufficient energy and nutrients. Swallowing difficulties (dysphagia) in pediatric populations can have a detrimental effect on dietary intake and, thus, growth and development. As a result, it is imperative to accurately identify and appropriately manage dysphagia in pediatric populations. This article provides an overview of dysphagia in children, as well as common causes of childhood swallowing difficulties, populations at risk for pediatric dysphagia, techniques used to assess swallowing in pediatric patients, and the current treatment options available for infants and children with dysphagia.

Reliability for Identification of a Select Set of Temporal and Physiologic Features of Infant Swallows

There is little reported evidence regarding the reliability of temporal and physiologic features of infant swallowing from videofluoroscopic swallowing studies (VFSS). The purpose of this retrospective study was to determine a reliable set of temporal and physiologic features from infant swallowing that can be measured from analysis of VFSS. Temporal and physiologic features for testing were determined from review of previously reported features of infant VFSS in the literature. Two novel analysts underwent three training sessions to learn and practice visual recognition of the proposed features. The two analysts then assessed 25 swallows from 10 total subjects’ VFSS. To establish inter- and intra-rater reliability, calculation of Pearson’s r was used for features that met criteria for parametric analysis and Spearman’s rank correlation coefficient was used for the non-continuous features. Percent agreement was used to report on the reliability of the dichotomous features due to insufficient variability for Spearman’s rho analyses. Fifteen of the 16 tested features were found to have acceptable inter- and intra-rater reliability measures, with each analyst achieving a correlation of 0.75 or higher. This project identifies 15 variables that can be reliably measured from infant VFSS. This information can be used to assist with determination of normal versus abnormal swallow features and in developing and testing therapeutic strategies for infants with dysphagia.

FIRST, DO NO HARM: A Response to "Oral Alimentation in Neonatal and Adult Populations Requiring High-Flow Oxygen via Nasal Cannula".

A recent paper [1] has proposed that the use of respiratory support delivered via high-flow nasal cannula (HFNC) does not have a direct impact on the safety of oral (PO, per os) feeding. As a group of NICU clinicians and researchers, we are writing to express our concern about the design and conclusions presented in this study. Specifically, the article does not present sufficient data for the NICU sample studied to support their conclusions in relation to this population (as detailed below). We believe that this could potentially place vulnerable infants at risk of unsafe feeding practices. Within the NICU environment, HFNC is used as an intervention for many infants with pulmonary disease. Common clinical benefits of HFNC support in infants identified in the literature include a ‘CPAP’ effect (i.e., delivering positive pressure that stents open the airway), providing anatomic O2 reservoirs in the pharynx and allowing rinsing of pharyngeal dead space [2, 3]. To swallow safely, the bolus needs to be contained in the oral cavity prior to the swallow, and the laryngeal vestibule needs to close (deglutition apnea) as the bolus moves through the pharynx, to ensure transport to the esophagus and not into the larynx or lower airway. To swallow safely during breastfeeding and bottle feeding, the precise timing of the suck-swallow-breath sequence needs to be maintained over every one of the swallows that occur in quick succession for minutes at a time while the infant is latched and suckling at the breast or bottle. We are not aware of any objective data using instrumental assessment that show that the presence of HFNC does not (a) impair swallow function during infant suckle feeding or (b) increase aspiration risk in NICU infants (many of whom are at heightened risk for aspiration from their underlying lung disease in itself). The Leder et al. paper [1] does not provide any such data but appears to encourage the practice of allowing (at least some) infants who are dependent on HFNC to feed PO. Of note, the authors report that 34 % (17/50) of infants on HFNC were deemed ‘safe’ to PO feed by MD/RN staff (although it appears that all continued to require tube feeds, indicating that they were not fully functional PO feeders, and is not clear how ‘safety’ was monitored). On examination of the information presented, it is apparent that none of the infants included in this study had a direct feeding evaluation (either formal clinical assessment or instrumental assessment) to confirm the safety of PO feeding. The authors report on their initial criteria for determining readiness to consider trying PO feeds, but make no mention of direct feeding evaluation and no & Pamela Dodrill PDodrill@partners.org

Pulmonary Function in Infants with Swallowing Dysfunction

Background Swallowing dysfunction can lead to recurring aspiration and is frequently associated with chronic symptoms such as cough and wheezing in infants. Our objective was to describe the characteristics of infants with swallowing dysfunction, determine if pulmonary function abnormalities are detectable, and if they improve after therapy. Methods We studied 38 infants with a history of coughing and wheezing who had pulmonary function tests performed within two weeks of their diagnosis of swallowing dysfunction. The raised lung volume rapid thoracoabdominal compression technique was used. After 6 months of therapy, 17 of the infants repeated the tests. Results Initially, 25 had abnormal spirometry, 18 had abnormal plethysmography, and 15 demonstrated bronchodilator responsiveness. Six months later test were repeated for seventeen patients. Ten patients had continued abnormal spirometry, two patients remained normal, three patients’ abnormal spirometry had normalized, and two patients’ previously normal studies became abnormal. Eight of the 17 patients had continued abnormal plethysmography, six had continued normal plethysmography, and three patients’ normal plethysmography became abnormal. After 6 months of treatment, eight patients demonstrated bronchodilator responsiveness, of which five continued to demonstrate bronchodilator responsiveness and three developed responsiveness. The remainder either continued to be non- bronchodilator responsive (two) or lost responsiveness (three.) The findings of the abnormal tests in most infants tested is complicated by frequent occurrence of other co-morbidities in this population, including gastroesophageal reflux in 23 and passive smoke exposure in 13 of the infants. Conclusions The interpretation of lung function changes is complicated by the frequent association of swallowing dysfunction with gastroesophageal reflux and passive smoke exposure in this population. Six months of medical therapy for swallowing dysfunction/gastroesophageal reflux did not significantly improve pulmonary function in these infants. Long-term studies will be necessary to determine which of these changes persists into adulthood.

Effect of Time and Temperature on Thickened Infant Formula

Background: Unlike adult populations, who primarily depend on liquids for hydration alone, infants rely on liquids to provide them with hydration and nutrition. Speech-language pathologists working within pediatric medical settings often identify dysphagia in patients and subsequently recommend thickened liquids to reduce aspiration risk. Caregivers frequently report difficulty attempting to prepare infant formula to the prescribed thickness. Materials and Methods: This study was designed to determine (1) the relationship between consistencies in modified barium swallow studies and thickened infant formulas and (2) the effects of time and temperature on the resulting thickness of infant formula. Prepackaged barium consistencies and 1 standard infant formula that was thickened with rice cereal and with 2 commercially available thickening agents were studied. Thickness was determined via a line spread test after various time and temperature conditions were met. Results: There were significant differences between the thickened formula and barium test consistencies. Formula thickened with rice cereal separated over time into thin liquid and solid residue. Formula thickened with a starch-based thickening agent was thicker than the desired consistency immediately after mixing, and it continued to thicken over time. The data from this project suggest that nectar-thick and honey-thick infant formulas undergo significant changes in flow rates within 30 minutes of preparation or if refrigerated and then reheated after 3 hours. Conclusions: Additional empirical evidence is warranted to determine the most reliable methods and safest products for thickening infant formula when necessary for effective dysphagia management.