Intensive Stepwise Method for Oral Intake Using a Combination of Transient Receptor Potential Stimulation and Olfactory Stimulation Inhibits the Incidence of Pneumonia in Dysphagic Older Adults

To the Editor: Dysphagia in older adults is an important cause of pneumonia, which causes high morbidity and mortality.1 The incidence of aspiration as a cause of community- and hospital-acquired pneumonia in older adults has been reported to be 67%.2 Rehospitalization after inpatient treatment of pneumonia occurs in one-tenth of all hospitalizations.3 A vicious spiral in which aspiration predisposes patients to pneumonia is generated and hard to avoid. In the course of treatment and care of aspiration pneumonia, one of the most critical and challenging questions is when and how such patients should start to eat. In a real clinical setting, when a patient is unable to receive a nutritionally adequate diet orally and the need for nutritional support is expected to last for more than 2 weeks, gastrostomy may be the route of choice for enteral feeding.4 Another report has shown that early tube feeding reduces care fatalities, whereas the use of enteral tube feeding has been found to increase the risk of death.5 We often vacillate in the choice of enteral feeding in a clinical setting. It was recently reported that the thermal and pharmacological stimulation of the transient receptor potential (TRP) V1 or TRPM8 can improve the latency of the swallowing reflex in older adults with dysphagia.6–9 Moreover, it was recently reported that nasal inhalation of volatile black pepper oil can activate the insular or orbitofrontal cortex, resulting in improvement of the reflexive swallowing movement.10 Therefore, a 2-year historical cohort study was conducted to determine the effect of an intensive stepwise method for starting oral intake in older adults with dysphagia that combines TRP superfamily stimulation of the swallowing reflex with the effect of aromatherapy using black pepper oil in 17 hospitalized patients with pneumonia, who had a past history of recurrent pneumonia in a 3-year period and were physically handicapped, mainly because of cerebrovascular disease. The incidence of pneumonia and febrile days were assessed with or without the intensive stepwise method (Table 1). The intensive stepwise method for starting oral intake advocated is as follows. Oral feeding of the older adults was postponed until their pneumonia was confirmed to be cured. Soon after patients were judged to be nearly cured of pneumonia based on the return of inflammation markers to the normal range and diminishing shadows of pneumonia on chest X-ray or computerized tomography, aromatherapy with black pepper oil was started as the first step. Aromatherapy was executed using a sheet of white nonwoven fabric (size 6.5 × 4.5 cm) adhered to the patient's gown near the neck area with volatile black pepper oil adhered to multiple carbon nanoparticles continuously diffused from the fabric. The second step was the additional application of capsaicin troches (round, 15 mm in diameter with a center hole 7 mm in diameter, capsaicin 1.5 μg/tablet), three times per day 3 days after the start of aromatherapy with black pepper oil.8 The third step was that jelly including a menthol ingredient (menthol gel) was provided as the first meal when eating was resumed 5 days after the addition of the capsaicin troches. The menthol gel (weight 80 g) was made of gelatin with menthol at a concentration of 10−3 M.9 The hardness, cohesion power, and adhesive power of the jelly were 5,700 N/m2, 39 J/m3, and 0.49 at 20°C, respectively. These parameters were recognized as being safe for swallowing by people with dysphagia. If patients were able to swallow the menthol jelly safely, they were provided in a step-by-step manner with the proper food texture depending on their ability to swallow such food as paste or pudding or usual meals including liquids and solids. Both phases were executed with usual care for the prevention of aspiration such as specific swallowing exercise by a speech pathologist and oral care by nurses after every meal. Despite the Charlson Comorbidity Index, oral intake before the intervention phase was greater and the number of total lymphocytes before oral intake in the control phase was less than that in the other phase (P<.01 and P<.05, respectively), the incidence of pneumonia and the number of febrile days for 1 month from the start of oral intake in the intervention phase were significantly less than that in the control phase (P<.01). The intensive stepwise method for starting oral intake in older adults with dysphagia may be effective in decreasing the incidence of pneumonia presumably induced by aspiration. This method may decrease the number of patients who require enteral tube feeding. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Takae Ebihara and Satoru Ebihara have a domestic patent in Japan for the effect of volatile black pepper oil on dysphasia (Japan domestic patent number 3762969, Date of registration with the Japan Patent Office: January 27, 2006). Takae Ebihara and Satoru Ebihara have obtained small royalties from a domestic patent for the effect of volatile black pepper oil on dysphasia. Funding was provided by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (20590694, 21390219), Research Grants for Longevity Sciences from the Ministry of Health, Labor and Welfare (20C-1, 19-02,21-005). Author Contributions: TE: study concept and design, analysis and interpretation of data, and preparation of letter. SE: study concept and design and preparation of letter. MY, MA, and SY: acquisition of data. HA: study oversight, interpretation of data and final approval of letter. Sponsor's Role: None.