Effects of Unilateral Vagotomy on LPS-Induced Aspiration Pneumonia in Mice

Respiratory-related dysphagia and aspiration pneumonia can be attributed to multiple causes. However, reproduction of multiple factor-related respiratory distress and aspiration pneumonia in a single animal model is challenging. To validate animals with vagal nerve palsy as novel models for severe aspiration pneumonia associated with respiratory distress, we investigated the effects of unilateral vagotomy on the swallowing function and severity of pneumonia after forced aspiration in mice. Unilateral vagotomy was performed in C57BL6 male mice that subsequently underwent evaluation of swallowing function by videofluoroscopic swallow study (VFSS) and histological assessments for aspiration pneumonia induced by lipopolysaccharide (LPS). VFSS examinations demonstrated that unilateral vagotomy did not cause apparent aspiration in mice, but it resulted in a significant loss of body weight (BW) due to decreased oral intake. In addition, when aspiration pneumonia was induced by forced administration of LPS, significantly prolonged BW loss and severe infiltration of inflammatory cells associated with aspiration pneumonia were observed in the mice that underwent unilateral vagotomy. In conclusion, the vagotomized mice showed appropriate characteristics as a model of aspiration pneumonia caused by multiple factors, including the paralysis of vocal fold movement and respiratory distress. This model can help elucidate the pathogenesis of aspiration pneumonia and the treatment methods for the respiration-compromised model.

Instructor Development Workshops for Advanced Life Support Training Courses Held in a Fully Virtual Space: Observational Study

Background

Various face-to-face training opportunities have been lost due to the COVID-19 pandemic. Instructor development workshops for advanced resuscitation (ie, advanced life support) training courses are no exception. Virtual reality (VR) is an attractive strategy for remote training. However, to our knowledge, there are no reports of resuscitation instructor training programs being held in a virtual space.

Objective

This study aimed to investigate the learning effects of an instructor development workshop that was conducted in a virtual space.

Methods

In this observational study, we created a virtual workshop space by using NEUTRANS (Synamon Inc)—a commercial VR collaboration service. The instructor development workshop for the advanced life support training course was held in a virtual space (ie, termed the VR course) as a certified workshop by the Japanese Association of Acute Medicine. We asked 13 instructor candidates (students) who participated in the VR course to provide a workshop report (VR group). Reports from a previously held face-to-face workshop (ie, the face-to-face course and group) were likewise prepared for comparison. A total of 5 certified instructor trainers viewed and scored the reports on a 5-point Likert scale.

Results

All students completed the VR course without any problems and received certificates of completion. The scores for the VR group and the face-to-face group did not differ at the level of statistical significance (median 3.8, IQR 3.8-4.0 and median 4.2, IQR 3.9-4.2, respectively; P=.41).

Conclusions

We successfully conducted an instructor development workshop in a virtual space. The degree of learning in the virtual workshop was the same as that in the face-to-face workshop.

Development of virtual reality content for learning Japan Prehospital Trauma Evaluation and Care initial assessment procedures

Aim

The Japan Prehospital Trauma Evaluation and Care (JPTEC) is a standardized educational program for prehospital trauma care in Japan. The initial assessment in the JPTEC course comprises a training segment that includes a 30‐min session. Given the limited face‐to‐face training due to the coronavirus disease 2019, virtual reality (VR) content has become an alternative. However, creating VR content typically requires the assistance of expert technicians. We aimed to create VR content for the initial assessment segment of the JPTEC and verify its educational effectiveness.

Methods

We created VR content for learning the initial assessment of the JPTEC using our easy‐to‐use VR content creation system. The participants played the VR content for 15 min. The number of times they “cleared” (i.e., made a correct decision and completed the initial assessment) was recorded every 5 min. Then, a JPTEC‐certified instructor tested their practical skills through face‐to‐face simulation.

Results

The authors had no specialized skills and created the VR content in 2 days. Fourteen students used the material. They cleared the scenario 3 (3–4) times in the first 5 min in 15 min, 5 (4–5) times in the second 5 min, and 5 (5–5) times in the third 5 min (P < 0.05). All participants passed the practical evaluation.

Conclusion

A shorter VR training developed using our easy‐to‐use VR content creation system can replace the 30‐min JPTEC session on the initial assessment. This system allows for the free and easy creation of VR content.

Frequent occurrence of postbreakfast syncope due to carotid sinus syndrome after surgery for hypopharyngeal cancer: A case report

RATIONALE

Syncope often occurs in patients with advanced head and neck cancers due to the stimulation of the autonomic nervous system by the tumor. Here, we describe a case of frequent syncopal episodes after laryngopharyngectomy for hypopharyngeal cancer. As all syncopal episodes were observed during the forenoon, we also evaluated the heart rate variability using ambulatory electrocardiography to determine why the syncopal episodes occurred during a specified period of the day.

PATIENT CONCERNS

A 73-year-old Japanese man who underwent laryngopharyngectomy for recurrent hypopharyngeal cancer started experiencing frequent episodes of loss of consciousness that occurred during the same time period (10:00-12:00). He had never experienced syncopal episodes before the operation. From 23 to 41 days postoperatively, he experienced 9 syncopal episodes that occurred regardless of his posture.

DIAGNOSES

Pharyngo-esophagoscopy revealed an anastomotic stricture between the free jejunum graft and the upper esophagus. Swallowing videofluoroscopy confirmed the dilatation of the jejunal autograft and a foreign body stuck on the oral side of the anastomosis. Contrast-enhanced computed tomography revealed that the carotid artery was slightly compressed by the edematous free jejunum. The patient was diagnosed with carotid sinus syndrome (CSS) as the free jejunum was dilated when consuming breakfast, which may have caused carotid sinus hypersensitivity and induced a medullary reflex.

INTERVENTIONS

Administration of disopyramide was effective in preventing syncope. Heart rate variability analysis using ambulatory electrocardiography showed that parasympathetic dominancy shifted to sympathetic dominancy during 10:00 to 12:00. The significant time regularity of the syncopal episodes may have been affected by modified diurnal variation in autonomic tone activity.

OUTCOMES

After the surgical release and re-anastomosis of the pharyngoesophageal stenosis via an open-neck approach, no recurrent episodes of syncope were reported.

LESSONS

We reported a case of frequent syncopal episodes limited to the forenoon due to CSS after surgery for hypopharyngeal carcinoma. The patient was treated with anticholinergics followed by the release and re-anastomosis of the pharyngoesophageal stenosis. When syncope occurs after surgery for head and neck lesions, CSS due to postoperative structural changes should be considered as a differential diagnosis of syncope.