The current definition, epidemiology, animal models and a novel therapeutic strategy for aspiration pneumonia

Impaired oral health: a required companion of bacterial aspiration pneumonia

Laryngotracheal aspiration has a widely-held reputation as a primary cause of lower respiratory infections, such as pneumonia, and is a major concern of care providers of the seriously ill orelderly frail patient. Laryngeal mechanical inefficiency resulting in aspiration into the lower respiratory tract, by itself, is not the cause of pneumonia. It is but one of several factors that must be present simultaneously for pneumonia to develop. Aspiration of oral and gastric contentsoccurs often in healthy people of all ages and without significant pulmonary consequences. Inthe seriously ill or elderly frail patient, higher concentrations of pathogens in the contents of theaspirate are the primary catalyst for pulmonary infection development if in an immunocompromised lower respiratory system. The oral cavity is a complex and ever changing eco-environment striving to maintain homogeneity among the numerous microbial communities inhabiting its surfaces. Poor maintenance of these surfaces to prevent infection can result inpathogenic changes to these microbial communities and, with subsequent proliferation, can altermicrobial communities in the tracheal and bronchial passages. Higher bacterial pathogen concentrations mixing with oral secretions, or with foods, when aspirated into an immunecompromised lower respiratory complex, may result in bacterial aspiration pneumonia development, or other respiratory or systemic diseases. A large volume of clinical evidence makes it clear that oral cleaning regimens, when used in caring for ill or frail patients in hospitals and long-term care facilities, drastically reduce the incidence of respiratory infection and death. The purpose of this narrative review is to examine oral health as a required causative companionin bacterial aspiration pneumonia development, and the effectiveness of oral infection control inthe prevention of this disease.

A Proposal for a Multidisciplinary Integrated Oral Health Network for Patients Undergoing Major Orthopaedic Surgery (IOHN-OS)

The passing of the years of life physiologically leads to the accumulation of changes in tissues in the oral cavity, influencing dentition, chewing and swallowing mechanisms, and the oral microbiota. Some diseases and medications can aggravate oral symptoms and negatively influence eating behaviours, increasing the likelihood of becoming malnourished. This could make older individuals more vulnerable to complications when undergoing major orthopaedic surgery. Hidden infection foci in the oral cavity are a recognised cause of post-operative periprosthetic joint infections. Dysfunctional oral problems might also compromise feeding after surgery when good nutrition represents a fundamental aspect of a proper recovery. To manage these shortcomings, in this article, the authors hypothesise a multidisciplinary path of care named the Integrated Oral Health Network applied to major Orthopaedic Surgery (IOHN-OS). This peri-operative initiative would include pre-operative oral health screening and risk management by a dental team, patient education programmes before and after surgery, and bedside gerodontology actions like oral care and meal and eating support for fragile individuals. The IOHN-OS has the potential to reshape the concept of suitability for major orthopaedic surgery and generate momentum for designing community-based surveillance programmes that can keep the mouths of older subjects healthy for a long time.

Effect of comorbid heart failure assessed by plasma B-type natriuretic peptide level on the activities of daily living in patients with hospitalization-associated disability after aspiration pneumonia

PURPOSE

We investigated the effects of comorbid heart failure on rehabilitation outcomes in patients with hospitalization-associated disability after aspiration pneumonia (AP).

METHODS

This study included 134 patients with hospitalization-associated disability after AP. Patients were classified into heart failure (B-type natriuretic peptide (BNP) ≧100 pg/ml, n = 39) and non-heart failure (BNP < 100 pg/ml, n = 95) groups, and the rehabilitation outcomes of both groups were compared.

RESULTS

Rehabilitation effectiveness was lower in heart failure group than in non-heart failure group (21.1 ± 22.6% vs 36.2 ± 30.8, p < 0.01). The rate of independent walking at discharge in heart failure group (28.2%) was significantly lower than in non-heart failure group (53.7%). Multiple linear regression analysis revealed that age, male, handgrip strength, quadriceps strength, functional oral intake scale, Mini Nutritional Assessment Short Form, and BNP were significantly associated with rehabilitation effectiveness.

DISCUSSION

Results suggest that comorbid heart failure has a negative impact on rehabilitation outcomes in patients with hospital-associated disability after AP.

High throughput sequencing technology reveals alteration of lower respiratory tract microbiome in severe aspiration pneumonia and its association with inflammation

BACKGROUND

Aspiration pneumonia is a common and severe clinical condition. The microbiome present in the lower respiratory tract plays a crucial role in regulating human inflammatory response. However, the relationship between the altered lower respiratory tract microbiome and inflammation in aspiration pneumonia remains inadequately explored.

PURPOSE

To investigate the alteration of the lower respiratory tract microbiome in severe aspiration pneumonia patients and explore the potential correlation between microbiome components and inflammatory response.

METHOD

Patients in the severe aspiration pneumonia group and control group were enrolled from the intensive care unit of Jinshan Hospital, Fudan University between December 31, 2020 and August 19, 2021. Sputum specimens were collected from all participants and subsequently subjected to 16S rDNA high throughput sequencing technology. The concentration of inflammatory cytokines in serum was measured using enzyme-linked immunosorbent assay (ELISA) kits, and collected data including patients' demographic information, clinical data, and laboratory examination results were recorded for further analysis.

RESULTS

Alteration in the lower respiratory tract microbiome was observed in severe aspiration pneumonia. Compared to the control group, a significant decrease in the relative abundance of Firmicutes was found at the phylum level (P < 0.01). At the family level, the relative abundance of Corynebacteriaceae, Enterobacteriaceae and Enterococcaceae increased significantly (P < 0.001, P < 0.05, P < 0.01). There were no significant differences in community diversity of the lower respiratory tract between the two groups. Patients in the severe aspiration pneumonia group exhibited significantly higher levels of inflammation compared to those in the control group. Correlation analysis showed that the relative abundance of Corynebacteriaceae was positively correlated with the expression level of IL-1β and IL-18 (P = 0.002, P = 0.02); the relative abundance of Enterobacteriaceae was negatively correlated with IL-4 (P = 0.011); no other significant correlations have been identified between microbiome and inflammatory indicators thus far (P > 0.05).

CONCLUSIONS

Alteration of the lower respiratory tract microbiome is critically involved in inflammation and disease progression in severe cases of aspiration pneumonia. The potential inflammation regulation properties of the microbiome hold promising value for developing novel therapeutic approaches aimed at mitigating the severity of the disease.

Determinants of Community-Acquired Pneumonia Among Adults Patients Attending Debre Berhan University Hakim Gizaw Hospital, Northeast Ethiopia: A Case-Control Study

Background

Community-acquired pneumonia among adults remains an important cause of morbidity and mortality in both industrialized and developing countries, including Ethiopia. Moreover, despite the availability of the best clinical standards, morbidity and mortality from community-acquired pneumonia have not improved over the last few decades. Therefore, prompt assessment and correction of modifiable risk factors are crucial to reduce morbidity and mortality. However, there are limited data on the determinants of community-acquired pneumonia among adults in the current study area.

Purpose

This study aimed to identify the determinants of community-acquired pneumonia among adult patients visiting Debre Berhan University Hospital, Ethiopia, May 2023.

Methods

A hospital-based unmatched case-control study design was conducted to select 113 cases and 113 controls using a consecutive sampling technique. Using the SPSS version 25 software bi-variable and multivariable logistic regression analyses were performed to identify the determinants of community-acquired pneumonia. Adjusted odds ratios with 95% confidence intervals and p-values < 0.05 were used to assess the level of significance.

Results

In this study, recent history of common cold [AOR: 4.35, 95% CI: (2.22, 8.51)], recent history of toothache [AOR: 2.51, 95% CI: (1.18, 5.33)], and not brushing teeth regularly [AOR, 2.79; 95% CI: (1.32, 5.88)] were significantly associated with community-acquired pneumonia.

Conclusion

In this study, common cold, recent history of toothache, and lack of regular oral hygiene were significantly associated with community acquired pneumonia in adults. Therefore, health promotion of oral hygiene and the common cold is recommended to decrease the risk of pneumonia.

Comparison of the thickness of the erector spinae muscles between aspiration pneumonia and bacterial pneumonia patients

BACKGROUND AND AIMS

Aspiration pneumonia is generally associated with deterioration of skeletal muscle mass, which is usually evaluated by the erector spinae muscle cross-sectional area (ESMCSA); however, no report has assessed ESMCSA in patients with aspiration pneumonia. Furthermore, erector spinae muscle thickness (ESMT) was developed to be easier to measure than ESMCSA. Therefore, this study investigated the relationship between ESMT and ESMCSA in aspiration pneumonia patients compared to bacterial pneumonia patients.

METHODS

We retrospectively collected data for 164 patients with aspiration pneumonia and 480 patients with bacterial pneumonia who were hospitalized at Fukujuji Hospital between September 2018 and May 2022. We assessed the correlations between ESMCSA and ESMT and compared the data between the two groups.

RESULTS

ESMT had a strong, proportional relationship with ESMCSA in all patients (r = 0.908, p < 0.001) and those with aspiration pneumonia (r = 0.896, p < 0.001). ESMCSA (median 671.8 mm2 [range 164.0-1636.7] vs. median 1057.0 mm2 [range 161.3-2412.5], p < 0.001) and ESMT (median 17.1 mm [range 6.95-34.4] vs. median 23.8 mm [range 6.95-43.7], p < 0.001) were significantly lower in patients with aspiration pneumonia. A multivariate analysis of aspiration pneumonia diagnosis showed significant independent differences from bacterial pneumonia in ESMCSA (odds ratio 0.998 [95% CI: 0.996-0.999], p = 0.001) and ESMT (odds ratio 0.90 [95% CI: 0.84-0.96], p = 0.002).

CONCLUSION

This study demonstrates a strong correlation between ESMCSA and ESMT. ESMT can be more easily used to evaluate skeletal muscle mass and can help in diagnosing aspiration pneumonia.

Clinically defined aspiration pneumonia is an independent risk factor associated with long-term hospital stay: a prospective cohort study

BACKGROUND

Long-term hospital stay is associated with functional decline in patients with pneumonia, especially in the elderly. Among elderly patients with pneumonia, aspiration pneumonia is a major category. Clinical definition is usually used because it can occur without apparent aspiration episodes. It is still not clear whether a long-term hospital stay is due to aspiration pneumonia itself caused by underlying oropharyngeal dysfunction or simply due to functional decline in elderly patients with multiple comorbidities during acute infection. The aim of this study is to identify whether clinically defined aspiration pneumonia itself was associated with a long-term hospital stay.

METHODS

A prospective observational study on community-acquired (CAP) or healthcare-associated pneumonia (HCAP) was conducted from January 2012 through January 2014. Aspiration pneumonia was clinically defined as pneumonia not only occurring in patients after documented aspiration episodes, but also occurring in those with underlying oropharyngeal dysfunction: chronic disturbances of consciousness and/or chronic neuromuscular diseases. We defined thirty-day hospital stay as a long-term hospital stay and compared it with logistic regression analysis. Potential confounders included age, sex, HCAP, body mass index (BMI), long-term bed-ridden state, heart failure, cerebrovascular disorders, dementia, antipsychotics use, hypnotics use, and CURB score which is a clinical prediction tool used to assess the severity, standing for; C (presence of Confusion), U (high blood Urea nitrogen level), R (high Respiratory rate), and B (low Blood pressure). In a sub-analysis, we also explored factors associated with long-term hospital stay in patients with aspiration pneumonia.

RESULTS

Of 2,795 patients, 878 (31.4%) had aspiration pneumonia. After adjusting potential confounders, the aspiration pneumonia itself was significantly associated with long-term hospital stay (adjusted odds ratio 1.44; 95% confidence interval 1.09-1.89, p < 0.01), as were higher age, male sex, high CURB score, HCAP, low BMI, heart failure, cerebrovascular disease, and antipsychotics use. Sub-analysis revealed factors associated with long-term hospital stay in the aspiration pneumonia, which included male sex, and multi-lobar chest X-ray involvement.

CONCLUSIONS

Clinically defined aspiration pneumonia itself was independently associated with long-term hospital stay. This result could potentially lead to specific rehabilitation strategies for pneumonia patients with underlying oropharyngeal dysfunction.

Clinical Utility of Pepsin and Bile Acid in Tracheal Secretions for Accurate Diagnosis of Aspiration in ICU Patients

BACKGROUND

Aspiration of stomach content or saliva in critical conditions-e.g., shock, intoxication, or resuscitation-can lead to acute lung injury. While various biomarkers in bronchoalveolar lavage fluids have been studied for diagnosing aspiration, none have been conclusively established as early indicators of lung damage. This study aims to evaluate the diagnostic value of pepsin, bile acid, and other biomarkers for detecting aspiration in an intensive care unit (ICU).

MATERIALS AND METHODS

In this study, 50 ICU patients were enrolled and underwent intubation before admission. The evaluation of aspiration was based on clinical suspicion or documented instances of observed events. Tracheal secretion (TS) samples were collected within 6 h after intubation using sterile suction catheters. Additional parameters, including IL-6, pepsin, and bile acid, were determined for analysis. Pepsin levels were measured with an ELISA kit, while bile acid, uric acid, glucose, IL-6, and pH value in the tracheal secretion were analyzed using standardized lab methods.

RESULTS

The 50 patients admitted to the ICU with various diagnoses. The median survival time for the entire cohort was 52 days, and there was no significant difference in survival between patients with aspiration pneumonia (AP) and those with other diagnoses (p = 0.69). Among the AP group, the average survival time was 50.51 days (±8.1 SD; 95% CI 34.63-66.39), while patients with other diagnoses had a mean survival time of 32.86 days (±5.1 SD; 95% CI 22.9-42.81); the survival group comparison did not yield statistically significant results. The presence of pepsin or bile acid in TS patients did not significantly impact survival or the diagnosis of aspiration. The p-values for the correlations between pepsin and bile acid with the aspiration diagnosis were p = 0.53 and p > 0.99, respectively; thus, pepsin and bile acid measurements did not significantly affect survival outcomes or enhance the accuracy of diagnosing aspiration pneumonia.

CONCLUSIONS

The early and accurate diagnosis of aspiration is crucial for optimal patient care. However, based on this study, pepsin concentration alone may not reliably indicate aspiration, and bile acid levels also show limited association with the diagnosis. Further validation studies are needed to assess the clinical usefulness and reliability of gastric biomarkers in diagnosing aspiration-related conditions. Such future studies would provide valuable insights for improving aspiration diagnosis and enhancing patient care.

Impacts of body positions on the geniohyoid muscle contraction and swallowing difficulty in healthy adults

BACKGROUND

Body positions affect swallowing and gastroesophageal reflux. Swallowing impairment is one of the main causes of aspiration pneumonia. To prevent pneumonia, evaluation of body positions on gastroesophageal reflux recommended 30 degrees or higher semi-recumbent positions. The geniohypoid muscle and tongue play central roles in swallowing. However, the effects of body positions on contracting rates in the geniohyoid muscle and tongue pressure are unclear. Moreover, correlations between geniohyoid muscle contracting rates and subjective swallowing difficulties are unclear.

AIMS

This study aimed to identify the proper body positions on contracting rates in the geniohyoid muscle, tongue pressure, and subjective swallowing difficulties.

MATERIALS & METHODS

Twenty healthy adults swallowed 15- or 50 ml of water at 90 degrees sitting, 60- and 30 degrees semi-recumbent, and 0 degrees supine positions. We scored the subjective swallowing difficulties and measured the tongue pressure and the number of swallows. An ultrasound evaluated the geniohyoid muscle size and contracting rates.

RESULTS

At sitting and 60 degrees semi-recumbent positions, the geniohyoid muscle showed greter contracting rates than at 30 degrees semi-recumbent and supine postions (P < 0.05), which resulted in easier swalloiwng. Greater tongue pressure was weakly correlated with fewer swallows (r = -0.339, P = 0.002), whereas the body positions did not affect.

CONCLUSION

Considering swallowing and gastroesophageal reflux together, a trunk angle of 60 degrees or more might be beneficial for reducing the risk of aspiration.

Computer-aided screening of aspiration risks in dysphagia with wearable technology: a Systematic Review and meta-analysis on test accuracy

Aspiration caused by dysphagia is a prevalent problem that causes serious health consequences and even death. Traditional diagnostic instruments could induce pain, discomfort, nausea, and radiation exposure. The emergence of wearable technology with computer-aided screening might facilitate continuous or frequent assessments to prompt early and effective management. The objectives of this review are to summarize these systems to identify aspiration risks in dysphagic individuals and inquire about their accuracy. Two authors independently searched electronic databases, including CINAHL, Embase, IEEE Xplore^® Digital Library, PubMed, Scopus, and Web of Science (PROSPERO reference number: CRD42023408960). The risk of bias and applicability were assessed using QUADAS-2. Nine (n = 9) articles applied accelerometers and/or acoustic devices to identify aspiration risks in patients with neurodegenerative problems (e.g., dementia, Alzheimer's disease), neurogenic problems (e.g., stroke, brain injury), in addition to some children with congenital abnormalities, using videofluoroscopic swallowing study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES) as the reference standard. All studies employed a traditional machine learning approach with a feature extraction process. Support vector machine (SVM) was the most famous machine learning model used. A meta-analysis was conducted to evaluate the classification accuracy and identify risky swallows. Nevertheless, we decided not to conclude the meta-analysis findings (pooled diagnostic odds ratio: 21.5, 95% CI, 2.7-173.6) because studies had unique methodological characteristics and major differences in the set of parameters/thresholds, in addition to the substantial heterogeneity and variations, with sensitivity levels ranging from 21.7% to 90.0% between studies. Small sample sizes could be a critical problem in existing studies (median = 34.5, range 18-449), especially for machine learning models. Only two out of the nine studies had an optimized model with sensitivity over 90%. There is a need to enlarge the sample size for better generalizability and optimize signal processing, segmentation, feature extraction, classifiers, and their combinations to improve the assessment performance. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/), identifier (CRD42023408960).

Respiratory aspiration during treatment with clozapine and other antipsychotics: a literature search and a pharmacovigilance study in VigiBase

INTRODUCTION

Antipsychotics (APs), during treatment or overdose, may be associated with respiratory aspiration.

AREAS COVERED

A PubMed search on September 30, 2022, provided 3 cases of respiratory aspiration during clozapine therapy and 1 case during an AP overdose. VigiBase records of respiratory aspiration associated with APs from inception until September 5, 2021, were reviewed. VigiBase, the World Health Organization's global pharmacovigilance database, uses a statistical signal for associations called the information component (IC).

EXPERT OPINION

The ICs (and IC₀₂₅) were 2.1 (and 2.0) for APs, 3.2 (and 3.0) for clozapine, 2.6 (and 2.4) for quetiapine, and 2.5 (and 2.2) for olanzapine. Cases of respiratory aspiration associated with APs included: 137 overdose/suicide cases (64 fatal) and 609 cases during treatment (385 fatal) including 333 taking clozapine (238 fatal). In logistic regression models of fatal outcomes, the odds ratios, OR, and (95% confidence intervals, CI) of significant independent variables were: a) 2.3 - 2.6 for clozapine in 3 samples of AP treatment of varying size, b) 1.9 (CI 1.0 to 3.5) for geriatric age in 284 patients on clozapine treatment, and c) 1.8 (CI 1.1 - 3.2) for antidepressant co-medication in 276 patients on non-clozapine APs. Multiple AP pharmacological mechanisms may explain respiratory aspiration.

Cost-effectiveness of professional and mechanical oral care for preventing pneumonia in nursing home residents

BACKGROUND

Pneumonia is common in nursing home residents and is a leading cause of hospitalization and death. Nursing home residents with cerebrovascular diseases and impaired consciousness are at high risk of aspiration pneumonia. Professional and mechanical oral care by dentists and hygienists in addition to daily oral care by caregivers was shown to be effective in preventing pneumonia in nursing home residents. However, professional and mechanical oral care has not been widely provided in Japan, while daily oral care by caregivers has been widely provided as a basic service in nursing homes. This study aimed to evaluate the cost-effectiveness of providing professional and mechanical oral care for preventing pneumonia in nursing home residents.

METHODS

Using a decision tree and Markov modeling, we conducted a cost-effectiveness analysis from the payer's perspective (social insurers and patients) in Japan.

RESULTS

The incremental cost-effectiveness ratio for professional and mechanical oral care compared with daily oral care only was calculated as 4,079,313 Japanese yen (¥; 33,994 United States dollars [US$], US$1 = ¥120) per quality-adjusted life year.

CONCLUSIONS

Using the official value of social willingness to pay for a one-quality-adjusted life year gain in Japan of ¥5 million (US$41,667) as the threshold to judge cost-effectiveness, providing professional and mechanical oral care is cost-effective. Our results suggest professional and mechanical oral care for preventing pneumonia in nursing home residents could be justifiable as efficient use of finite healthcare resources. The results have implications for oral care in nursing homes both in Japan and worldwide.

Recent advances in ginsenosides against respiratory diseases: Therapeutic targets and potential mechanisms

BACKGROUND

Respiratory diseases mainly include asthma, influenza, pneumonia, chronic obstructive pulmonary disease, pulmonary hypertension, lung fibrosis, and lung cancer. Given their high prevalence and poor prognosis, the prevention and treatment of respiratory diseases are increasingly essential. In particular, the development for the novel strategies of drug treatment has been a hot topic in the research field. Ginsenosides are the major component of Panax ginseng C. A. Meyer (ginseng), a food homology and well-known medicinal herb. In this review, we summarize the current therapeutic effects and molecular mechanisms of ginsenosides in respiratory diseases.

METHODS

The reviewed studies were retrieved via a thorough analysis of numerous articles using electronic search tools including Sci-Finder, ScienceDirect, PubMed, and Web of Science. The following keywords were used for the online search: ginsenosides, asthma, influenza, pneumonia, chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), lung fibrosis, lung cancer, and clinical trials. We summarized the findings and the conclusions from 176 manuscripts on ginsenosides, including research articles and reviews.

RESULTS

Ginsenosides Rb1, Rg1, Rg3, Rh2, and CK, which are the most commonly reported ginsenosides for treating of respiratory diseases, and other ginsenosides such as Rh1, Rk1, Rg5, Rd and Re, all primarily reduce pneumonia, fibrosis, and inhibit tumor progression by targeting NF-κB, TGF-β/Smad, PI3K/AKT/mTOR, and JNK pathways, thereby ameliorating respiratory diseases.

CONCLUSION

This review provides novel ideas and important aspects for the future research of ginsenosides for treating respiratory diseases.

Respiratory aspiration during treatment with benzodiazepines, antiepileptic and antidepressant drugs in the pharmacovigilance database from VigiBase

INTRODUCTION

Three psychotropic drug classes, benzodiazepines, antiepileptic drugs (AEDs) and antidepressants (ADs), whether used in treatment or overdose, may be associated with respiratory aspiration. Polypharmacy was defined by counting suspected drugs from these classes or two others, antipsychotics and opioids. The confounding effects of polypharmacy were considered in this study.

AREAS COVERED

VigiBase records of respiratory aspiration associated with benzodiazepines, AEDs, and/or ADs from inception until September 5, 2021, were reviewed. VigiBase, the World Health Organization's global pharmacovigilance database, uses a statistical signal for associations called the information component (IC).

EXPERT OPINION

The ICs (and IC₀₂₅) were benzodiazepines 2.8 (and 2.6), AEDs 1.6 (and 1.5), and ADs 1.4 (and 1.3). The cases of respiratory aspiration associated with at least one drug from these 3 classes included: 1) 553 cases absent any known overdose (2.8±1.7 drugs) and 2) 347 overdose cases (2.9±1.8 drugs). Little support for the association of respiratory aspiration and benzodiazepine, AED or AD monotherapy in therapeutic dosages was found. Studies of the association between benzodiazepine monotherapy and respiration aspiration are needed in geriatric patients. ADs added to other medications increased lethality in all cases of respiratory aspiration including those associated with overdose, polypharmacy and/or major medical problems.

Validation of Earphone-Type Sensors for Non-Invasive and Objective Swallowing Function Assessment

Standard methods for swallowing function evaluation are videofluoroscopy (VF) and videoendoscopy, which are invasive and have test limitations. We examined the use of an earphone-type sensor to noninvasively evaluate soft palate movement in comparison with VF. Six healthy adults wore earphone sensors and swallowed barium water while being filmed by VF. A light-emitting diode at the sensor tip irradiated infrared light into the ear canal, and a phototransistor received the reflected light to detect changes in ear canal movement, including that of the eardrum. Considering that the soft palate movement corresponded to the sensor waveform, a Bland–Altman analysis was performed on the difference in time recorded by each measurement method. The average difference between the time taken from the most downward retracted position before swallowing to the most upward position during swallowing of the soft palate in VF was −0.01 ± 0.14 s. The Bland–Altman analysis showed no fixed or proportional error. The minimal detectable change was 0.28 s. This is the first noninvasive swallowing function evaluation through the ear canal. The earphone-type sensor enabled us to measure the time from the most retracted to the most raised soft palate position during swallowing and validated this method for clinical application.

The Relationship Between Dysphagia and Pneumonia in Acute Stroke Patients: A Systematic Review and Meta-Analysis

Background

Dysphagia is a common complication after stroke and is associated with the development of pneumonia. This study aimed to summarize the relationship between dysphagia and pneumonia in post-stroke patients.

Materials and Methods

Articles published up to November 2021 were searched in the PubMed, Embase, Cochrane library, and Scopus databases. Studies that investigated the development of pneumonia in acute stroke patients with and without dysphagia were included. The methodological quality of individual studies was evaluated using the Risk Of Bias In Non-randomized Studies-of Interventions tool, and publication bias was evaluated using a funnel plot and Egger's test.

Results

Of 5,314 studies, five studies were included in the meta-analysis. The results revealed that the incidence of pneumonia was significantly higher in the dysphagia group than in the non-dysphagia group (OR 9.60; 95% CI 5.75–16.04; p &lt; 0.0001; I2 = 78%). There was no significant difference in the mortality rate between the two groups (OR 5.64; 95% CI 0.83–38.18; p = 0.08; I2 = 99%).

Conclusion

Dysphagia is a significant risk factor for pneumonia after stroke. The early diagnosis and treatment of dysphagia in stroke patients are important to prevent stroke-associated pneumonia.