Study design and population
Given the limited occurrence of pediatric trauma cases with dysphagia, it is difficult to accumulate cases; therefore, we decided to accumulate findings through a case-series approach in this study. This case-series study was performed at a pediatric emergency center, a tertiary-care facility approved by the Ministry of Health, Labor, and Welfare. Patients were enrolled from April 1, 2012, to March 31, 2022. We included patients with trauma aged < 16 years who were intubated, including patients with short-term (< 48 h) ventilatory management. We excluded the following patients: those who died, had a tracheostomy, were evaluated by a speech-language pathologist or nurse for more than 72 h after extubation, or were originally on home ventilator management. Swallowing function was assessed by nurses with more than 3 years of experience in the pediatric intensive care unit (PICU). The nurses conducted the evaluation based on a feeding and swallowing training protocol developed by a multidisciplinary team at our facility. In principle, the nurses made the final judgment based on the presence or absence of dysphagia. However, in case of doubt, the decision was made after consultation with speech-language pathologists. In this study, speech-language pathologists did not perform videofluoroscopic swallow studies or fiberoptic endoscopic swallow evaluations because of the acute phase of swallowing.
Ethics approval and consent to participate
The study protocol was approved by the Ethics Committee of the Japanese Red Cross Kumamoto Hospital (approval number 510), which waived the requirement for obtaining informed consent. All the methods and procedures carried out in this study were in accordance with relevant guidelines and regulations.
Patient data were obtained from medical records. The demographic and clinical variables collected included age, sex, weight, PICU admission diagnosis, Abbreviated Injury Scale (AIS), and Injury Severity Score (ISS). The primary outcome measure was the presence or absence of signs of dysphagia on the first feeding following extubation, such as feeding-related coughing, choking, wet and gurgling voice, breathing quality, and/or bradycardia with desaturation. The first evaluation method was the modified water swallowing test9, as per our protocol. First, the patients were instructed to drink 1 mL of cold water to ensure there was no choking, wet hoarseness, or respiratory changes. If the patients swallowed three times without problems, they proceeded to the trial feeding phase with swallowing jellies. At this point, if the patients could chew and swallow adequately without experiencing choking, wet hoarseness, or respiratory changes, they were considered to have no dysphagia in this study. In the case of infants, a nipple was introduced into the mouth to confirm that sucking was sufficient. Initially, 1-mL milk was provided via a bottle three times to confirm the absence of choking, wet hoarseness, or respiratory changes. Subsequently, 10-mL milk was provided via a bottle; if no problems arose, the patient was considered free of dysphagia. The secondary analysis examined the occurrence of post-extubation dysphagia in terms of the following patient outcomes: length of PICU stay, length of hospital stay, time elapsed from extubation to initiation of oral intake, time to reach total oral intake, enteral feeding at hospital discharge, post-extubation pneumonia, and reintubation.
Categorical data (sex, primary diagnosis, age 0–24 months vs. 25 months and above, presence of post-extubation dysphagia, need for emergency intubation, complex chronic conditions, operation, prior use of vasopressors, neuromuscular blockade, benzodiazepine, barbiturate, and opioids) were reported as frequencies and percentages and presented as median and interquartile range.
Comparison between the control and post-extubation dysphagia groups was based on the Mann–Whitney U test for continuous variables and Fisher’s exact test for categorical variables. All statistical tests were two-tailed, and p < 0.05 was considered significant. Data were analyzed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria). In particular, it is a modified version of the R commander designed to add statistical functions frequently used in biostatistics.