ANTHROPOLOGICAL RESEARCHES AND STUDIES

ASPIRATION PNEUMONIA: A COMPREHENSIVE SCOPING REVIEW ON PATHOPHYSIOLOGY, DIAGNOSIS, TREATMENT, AND PREVENTION

Marvi SULA (1), Alma CANI (2) 
Keywords: aspiration pneumonia; dysphagia; elderly patients; pulmonary infections; antibiotic therapy; aspiration prevention

DOI: https://doi.org/10.26758/16.1.35

(1, 2) Faculty of Medicine, University of Medicine of Tirana, Tirana, Albania

(1) https://orcid.org/0009-0007-3721-2292  (2)  https://orcid.org/0009-0007-4530-2167

Address correspondence to: Marvi SULA, Anaesthesiology and intensive care resident, Faculty of Medicine, Department of Surgery, University of Medicine of Tirana, Rruga e Dibrës Nr. 371, AL1005, Tiranë, Albania, phone: +355676505008, e-mail: marvisula04@gmail.com

Abstract

Objective: Aspiration pneumonia is a serious respiratory infection caused by the inhalation of foreign material into the lungs, primarily affecting older adults and individuals with dysphagia or neurological disorders. The purpose of this study is to systematically review and synthesize current evidence on the pathophysiology, diagnosis, treatment, and prevention of aspiration pneumonia, while identifying gaps in existing research to inform future clinical practice.

Materials and methods: A scoping review was conducted following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Peer-reviewed articles, clinical trials, observational studies, and systematic review published between 2015 and 2024 were retrieved from PubMed, Scopus, and Web of Science. Eligible studies focused on adult populations and addressed epidemiology, microbiology, diagnosis, treatment, or prevention of aspiration pneumonia. Data extraction included study design, diagnostic methods, microbial findings, treatment strategies, and preventive interventions.

Results and conclusions: Consistent with previous research, advanced age, dysphagia, gastroesophageal reflux disease (GERD), and poor oral hygiene were identified as the primary risk factors contributing to the development of aspiration pneumonia. Patients with neurological disorders, such as stroke and Parkinson’s disease, were especially vulnerable. Diagnostic challenges remain significant due to the overlap of aspiration pneumonia symptoms with other forms of pneumonia and the limitations of microbiological testing methods. Next-generation sequencing (NGS) has emerged as a promising tool for more accurate pathogen identification. Regarding treatment strategies, antibiotic therapy remains the cornerstone of management. However, evidence from recent studies suggests that short-course antibiotic therapy (≤7 days) may be as effective as longer regimens, and routine anaerobic coverage may not always be necessary.

Keywords: aspiration pneumonia; dysphagia; elderly patients; pulmonary infections; antibiotic therapy; aspiration prevention

Suggested citation (APA):

Sula, M., & Cani, A. (2026). Aspiration pneumonia: A comprehensive scoping review on pathophysiology, diagnosis, treatment, and prevention. Anthropological Researches and Studies, 16, 542–568. https://doi.org/10.26758/16.1.35

Introduction

Definition of Aspiration Pneumonia

Aspiration pneumonia is a serious lung infection that occurs when food, liquids, saliva, or gastric contents are inhaled into the lower respiratory tract instead of being swallowed into the esophagus. Unlike aspiration pneumonitis, which results from the chemical injury caused by the acidic nature of gastric contents and is typically sterile and noninfectious, aspiration pneumonia involves a secondary bacterial infection following the aspiration event. This infection leads to an inflammatory response, impaired gas exchange, and respiratory distress. The condition is commonly viewed as part of a broader spectrum of pulmonary infections, encompassing both community-acquired and hospital-acquired pneumonia, with aspiration serving as a crucial mechanism for its development. (Almirall et al., 2021; Komiya et al., 2015; Mandell & Niederman, 2019; Neill & Dean, 2019).

Aspiration pneumonia is particularly prevalent among vulnerable populations, especially older adults and individuals residing in long-term healthcare facilities. Patients with neurological disorders such as stroke, Parkinson’s disease, and Alzheimer’s disease are at an elevated risk due to impaired swallowing mechanisms (dysphagia) and reduced cough reflex, which predispose them to recurrent episodes of aspiration. Additionally, critically ill patients in intensive care units (ICUs) and those requiring mechanical ventilation are highly susceptible, further complicating the diagnosis and management of this condition (Komiya et al., 2015; Dibardino & Wunderink, 2015, Rodríguez & Restrepo, 2019). Given its complex pathophysiology and diagnostic challenges, aspiration pneumonia remains a significant concern in both acute and long-term healthcare settings.

Importance of Aspiration Pneumonia in Healthcare

Aspiration pneumonia represents a major healthcare burden due to its high prevalence, associated morbidity, and significant mortality rates, particularly among the elderly and patients with multiple comorbidities. It is a leading cause of pneumonia in ICU settings and is frequently observed in patients with conditions that impair swallowing and airway protection (Abe et al., 2020; Lanspa et al., 2015; Manabe et al., 2015).

The condition is linked to increased hospitalization rates, prolonged hospital stays, and a heightened risk of complications such as respiratory failure, sepsis, and acute respiratory distress syndrome (ARDS). Studies have shown that aspiration pneumonia contributes significantly to in-hospital mortality and increases the likelihood of 30-day readmission, emphasizing the urgent need for improved prevention and management strategies (Komiya et al., 2016; Lanspa et al., 2015). Given the rising aging population and the increasing prevalence of neurodegenerative diseases, aspiration pneumonia is expected to remain a critical public health challenge, necessitating further research into early detection, targeted treatment, and effective preventive measures.

Purpose and Objectives

Purpose: To systematically review evidence from 2015–2024 regarding aspiration pneumonia in adults and synthesize findings on epidemiology, microbiology, diagnosis, treatment, and preventive interventions to inform clinical practice and research.

Specific Objectives:

  1. Describe epidemiological trends and principal risk factors associated with aspiration pneumonia.
  2. Summarize microbiological profiles and implications for empiric antibiotic therapy.
  3. Evaluate diagnostic modalities and their limitations, including molecular methods.
  4. Assess treatment strategies and preventive interventions, identifying research gaps.

Materials and methods

Study design: This scoping review was designed to map the breadth of evidence on aspiration pneumonia across all eligible study designs, including empirical studies, systematic reviews, and evidence-based narrative reviews. The review adhered to the PRISMA-ScR extension for scoping reviews (Page et al., 2021). Recognising that the included literature spans multiple study types — observational cohorts, systematic reviews, evidence-based narrative syntheses, and clinical statements — a scoping framework was considered more appropriate than a strictly defined systematic review, which typically restricts inclusion to empirical designs only.

Data sources and search strategy: PubMed, Scopus, and Web of Science were searched for studies published from January 1, 2015, to December 31, 2024. The following full search string was applied in PubMed (adapted with field-specific syntax for Scopus and Web of Science): (“aspiration pneumonia”[MeSH Terms] OR “aspiration pneumonia”[Title/Abstract]) AND (“dysphagia”[MeSH Terms] OR “swallowing disorder*”[Title/Abstract] OR “microbiology”[Title/Abstract] OR “pathogen*”[Title/Abstract] OR “diagnosis”[MeSH Terms] OR “diagnostic*”[Title/Abstract] OR “treatment”[MeSH Terms] OR “antibiotic*”[Title/Abstract] OR “management”[Title/Abstract] OR “prevention”[MeSH Terms] OR “oral hygiene”[Title/Abstract] OR “risk factor*”[Title/Abstract]) AND (“2015/01/01″[Date – Publication]: “2024/12/31″[Date – Publication]) AND (English[Language]) AND (humans[MeSH Terms]). Boolean operators AND/OR were applied throughout. Filters: publication date 2015–2024, English language, human studies. Last search conducted: December 31, 2024.

Eligibility criteria: Included sources were peer-reviewed, English-language publications addressing epidemiology, microbiology, diagnosis, treatment, or prevention of aspiration pneumonia in adult human populations (aged ≥18 years). Eligible study types included: empirical studies (randomised controlled trials, cohort, case-control, cross-sectional, and quasi-experimental designs), systematic reviews and meta-analyses, and evidence-based narrative reviews and clinical practice guidelines. Excluded were: pediatric studies (population aged <18 years), animal studies, single case reports without broader synthesis, opinion letters without supporting data, non-peer-reviewed grey literature, and studies published before January 1, 2015.

Rationale for Exclusion of Older Studies: Studies published before 2015 were excluded to ensure that the review reflects the most current understanding of aspiration pneumonia. In the past decade, there have been substantial shifts in diagnostic definitions, microbial identification techniques (including molecular and sequencing-based methods), and antibiotic stewardship practices. Older research often relied on outdated microbiological methods that overemphasized anaerobic pathogens and lacked the precision of modern molecular diagnostics. Furthermore, recent clinical guidelines (e.g. BTS 2023) have revised management approaches and definitions of aspiration-related syndromes. Restricting inclusion to the 2015–2024 period therefore provides a focused synthesis of contemporary evidence relevant to current clinical practice and public health policy.

Study selection: Two independent reviewers (G.S. and co-reviewer) screened all records at title/abstract stage and subsequently at full-text stage. Prior to screening, both reviewers completed a calibration exercise on a 5% random sample (n≈108 records) to harmonise interpretation of inclusion and exclusion criteria. A standardised data-extraction form was applied throughout. For borderline cases unresolved by consensus, an AI-assisted citation-ranking algorithm (ASReview Lab, version 1.6, n.d.) ranked records by predicted relevance (threshold: 0.50); all AI-flagged inclusions were subsequently validated by both reviewers before final assignment. An audit trail documenting all decisions and protocol amendments was maintained. PRISMA exclusion accounting: Of 3,408 records identified, 1,241 duplicates were removed, leaving 2,167 records for title/abstract screening. Of these, 1,984 were excluded (wrong topic: n=1,102; wrong population [paediatric or animal]: n=423; wrong language: n=309; clearly non-peer-reviewed: n=150). The remaining 183 records proceeded to full-text review. At full-text stage, 131 were excluded: publication date outside 2015–2024 (n=18); wrong study design (n=47); population outside scope (n=28); outcomes not addressed (n=31); full text unavailable (n=7). A total of 52 sources met all eligibility criteria and were included. A PRISMA flow diagram summarises the selection process (Figure 1).

Data extraction and quality assessment: Data included study design, setting, sample size, interventions, and outcomes. The following methods were used for quality appraisal: The Newcastle–Ottawa Scale (NOS) was used for cohort, case-control, and cross-sectional studies evaluating risk factors or outcomes (Wells et al., 2014; Stang, 2010; Hartling et al., 2013; Lo et al., 2014; Gláucia et al., 2013; Shi et al., 2022). The Cochrane Risk of Bias 2 (RoB 2) tool was applied to randomized controlled trials assessing interventions or treatments (Sterne et al., 2019; Flemyng et al., 2023; Crocker et al., 2023; Kotz & West, 2021; Nejadghaderi et al., 2024). The AMSTAR-2 checklist was used for systematic reviews and meta-analyses identified during screening (Shea et al., 2017; Lu et al., 2020; Puljak et al., 2023; Perry & Davies, 2021; Li et al., 2021). (Table 1)

Table 1

Quality assessment criteria tools (to see Table 1, please click here)

Data synthesis: Due to the heterogeneity in study designs, populations, and outcome measures across included sources, quantitative meta-analysis was not performed. Instead, a thematic synthesis approach was applied, following the framework described by Thomas and Harden (2008). Included studies were coded by: (1) thematic domain (epidemiology and risk factors; microbiology; diagnosis; treatment; prevention); (2) study design; (3) population characteristics; and (4) direction and magnitude of effect (where reported). Within each domain, findings were narratively compared across study types, with attention to consistency of direction, sample characteristics, and methodological quality. Evidence mapping tables (Table 2; Table 3) were constructed to provide a structured visual summary of included sources by domain and study design. Quality appraisal scores (Table 2, Quality Score column) were used to contextualise the weight attributed to individual findings: high-quality sources (NOS ≥7/9; RoB 2 ‘low risk’; AMSTAR-2 ‘high’ or ‘moderate’) were treated as primary evidence, while moderate- and low-quality sources informed secondary or contextual conclusions only.

Figure 1

PRISMA flow diagram (to see Figure 1, please click here)

Artificial intelligence tools were used in two distinct capacities. First, ASReview Lab (version 1.6; ASReview Lab, n.d.) was used during the citation-screening phase exclusively to rank borderline records by predicted relevance; the tool was set with a relevance threshold of 0.50, and all records ranked above this threshold were independently reviewed by both human reviewers before inclusion decisions were finalised. No record was included solely on the basis of the AI ranking. Second, a large language model was used post-selection to assist with organising, paraphrasing, and structuring extracted data into narrative summaries; it had no role in study selection, data extraction, or quality appraisal. All AI-assisted text was manually verified against source documents by the authors. This use of AI is disclosed in accordance with emerging editorial transparency standards.

Results

Study selection: Of 3,408 records identified, 2,167 remained after duplicate removal. Following title/abstract and full-text screening against pre-specified eligibility criteria, 52 sources were included in the final synthesis. Detailed exclusion accounting is provided in the Methods section and in Figure 1). The characteristics of the included studies are summarized in Table 2.

Table 2.

Characteristics of Included Studies (to see Table 2, please click here)

Epidemiology and risk factors: Advanced age, dysphagia, GERD, and poor oral hygiene were the most consistent predictors of aspiration pneumonia. Nursing home residents, post-stroke patients, and individuals with neurodegenerative disorders were disproportionately affected.

Microbiology: Aerobic and mixed flora predominated, with Streptococcus pneumoniae, oral streptococci, and Klebsiella species (spp.) most common. Anaerobes were variably reported, suggesting their role may be less central than historically assumed.

Diagnostics: Imaging (CXR, CT) and microbiological culture remained mainstays. Next-generation sequencing (NGS) and PCR-based assays showed promise for pathogen identification in culture-negative cases.

Treatment: Short-course (≤7 days) antibiotic regimens achieved comparable outcomes to longer courses. Routine anaerobic coverage is not universally required unless abscess or necrosis is suspected. Supportive interventions (postural care, swallowing therapy) remain critical.

Prevention: Dysphagia screening and comprehensive oral care significantly reduced aspiration pneumonia rates in high-risk groups. Multidisciplinary teams achieved better outcomes than single-discipline interventions.

The summaries of key findings are presented in Table 3.

Table 3.

Summary of key findings by objective (to see Table 3, please click here)

Discussion

This systematic literature review synthesizes contemporary evidence on aspiration pneumonia (AP) in adults, encompassing studies published between 2015 and 2024. The findings demonstrate that AP remains a significant clinical challenge, particularly in older adults, individuals with neurological disorders, and institutionalized populations. Despite technological advances in diagnostics and treatment, aspiration pneumonia continues to carry a high burden of morbidity, mortality, and healthcare utilization. The synthesis also highlights a progressive shift in microbial patterns, a lack of consensus in diagnostic definitions, and an evolving understanding of prevention and antibiotic management.

Epidemiology and Risk Factors

The epidemiological evidence across the included studies consistently identifies advanced age (Niederman & Cillóniz, 2022; Zhao et al., 2023), dysphagia (Cheng & Botz, 2018; Pan et al., 2024; Scannapieco, 2021), gastroesophageal reflux disease (GERD) (Kosutova & Mikolka, 2021; Mandell & Niederman, 2019)., and poor oral hygiene as the most influential risk factors (Elmahdi et al., 2023; Khadka et al., 2020), which reaffirm that aspiration pneumonia is largely a disease of frailty, occurring in patients with impaired swallowing mechanisms, diminished cough reflexes, and compromised immune defenses. Cohort studies, such as those by Liu et al. (2023) and Chen et al. (2021), demonstrate that the incidence of aspiration pneumonia rises steeply among nursing home residents and post-stroke patients, reflecting both physiologic vulnerability and environmental factors like inadequate oral care.

The intersection between aging physiology (Khadka et al., 2020) and aspiration risk (O’Keeffe, 2019) underscores the importance of swallowing function assessment in geriatric care. Oropharyngeal dysphagia affects up to 50% of institutionalized older adults, yet screening remains inconsistent. The review also identified cognitive impairment, dependency for feeding, and polypharmacy as important but underexplored risk modifiers (Kosutova & Mikolka, 2021; Son et al., 2017).

Microbiology and Pathophysiology

Historically, aspiration pneumonia was considered primarily an anaerobic infection arising from oropharyngeal flora (Akata et al., 2019; Ishii, 2020). However, the collective evidence over the past decade challenges this notion. The microbiological landscape is now dominated by aerobic and facultative organisms such as Streptococcus pneumoniae, viridans streptococci, Klebsiella pneumoniae, Haemophilus influenzae, and mixed aerobic–anaerobic communities (Akata et al., 2019; Xu et al., 2024), which align with earlier work suggesting that the routine use of anaerobic antibiotic coverage may be unnecessary except in specific clinical contexts (e.g., abscess formation, necrotizing pneumonia, or severe periodontal disease) (Ishii, 2020).

This evolving microbiology likely reflects both improved oral hygiene and changes in healthcare exposure patterns (Khadka et al., 2020). Frequent hospitalization, prior antibiotic use, and residence in long-term care facilities contribute to colonization with more resistant aerobic pathogens. The increasing prevalence of Enterobacteriaceae and Pseudomonas aeruginosa in certain studies raises concerns about healthcare-associated aspiration events. These shifts carry important implications for empiric antibiotic selection and stewardship.

Emerging technologies such as next-generation sequencing (NGS) have enhanced detection of polymicrobial infections and identified novel or unexpected organisms, broadening the understanding of the lung microbiome. The presence of commensal bacteria in lower airway samples supports the concept that aspiration pneumonia represents a dysbiosis of the oropharyngeal–pulmonary microbiome rather than a simple infection by a single pathogen (Zhang et al., 2022). Translating this insight into therapeutic strategies, such as microbiome restoration or probiotic interventions, remains an exciting frontier for future studies.

Clinical Presentation of Aspiration Pneumonia

The clinical presentation of aspiration pneumonia can vary widely, depending on the severity of the aspiration event, the type of material aspirated, and the patient’s overall health status. However, some common symptoms are frequently observed in affected individuals:

Fever: A hallmark of infection, fever is often present in aspiration pneumonia, signaling an immune response to bacterial colonization in the lungs (Abe et al., 2020; Mandell & Niederman, 2019).

Cough: Patients often experience a persistent cough, which may produce mucopurulent or foul-smelling sputum due to the presence of mixed bacterial infections (Abe et al., 2020; Yoshimatsu & Smithard, 2022).

Dyspnea (difficulty breathing): As infection spreads and inflammation worsens, gas exchange in the lungs becomes compromised, leading to shortness of breath, increased respiratory effort, and even respiratory distress (Mandell & Niederman, 2019).

Pleuritic chest pain: Inflammation of the lung lining (pleura) can cause sharp chest pain, particularly when breathing deeply or coughing.

Fatigue and altered mental status: In elderly or frail individuals, aspiration pneumonia may not always present with classic respiratory symptoms. Instead, patients may exhibit confusion, lethargy, or general functional decline, which can delay recognition of the infection (Yoshimatsu & Smithard, 2022).

Diagnostic Challenges and Innovations

Despite decades of study, the diagnosis of aspiration pneumonia remains fraught with ambiguity. Clinical definitions vary widely, often conflating aspiration pneumonitis (chemical injury) and aspiration pneumonia (infectious process). The lack of standardized criteria contributes to diagnostic inconsistency across studies and complicates epidemiological comparisons. Current clinical practice typically relies on the presence of risk factors for aspiration combined with radiologic findings of pneumonia; however, these criteria lack specificity. Since these patients may not display overt signs of aspiration, their pneumonia may only be detected once the infection becomes severe, making early diagnosis critical (Simpson et al., 2023).

Chest radiography, while widely available, cannot reliably differentiate aspiration pneumonia from other pneumonic processes. Computed tomography (CT) improves detection of dependent lobe infiltrates but adds cost and radiation exposure (Zhang et al., 2022). Microbiological confirmation remains difficult because expectorated sputum is often contaminated by oral flora. Several included studies reported the value of fiberoptic bronchoscopy and protected specimen brush techniques, although these are invasive and limited to selected populations.

Recent advances, such as polymerase chain reaction (PCR)-based assays and next-generation sequencing (NGS) (Zhang et al., 2022), offer rapid, culture-independent diagnostics that may redefine pathogen identification in the near future. However, their role in guiding therapy remains under investigation. Future research should prioritize the development of validated clinical–microbiological algorithms for differentiating aspiration pneumonia from other lower respiratory infections.

Treatment and Antibiotic Stewardship

Evidence on treatment strategies highlights growing support for shorter antibiotic regimens and more judicious antimicrobial use. Studies such as Brumit et al. (2020) reported that short-course antibiotic therapy (five to seven days) was equally effective as longer durations in achieving clinical cure and preventing relapse. Data are consistent with general pneumonia guidelines from the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS), which advocate shorter durations of therapy for stable responders (Dragan et al., 2018; Aga et al., 2021).

Another consistent theme is the reconsideration of routine anaerobic coverage (Yoshimatsu et al., 2023; Bowerman et al., 2018). Traditional regimens including clindamycin or beta-lactam/beta-lactamase inhibitors were based on older microbiologic concepts. Recent evidence, however, supports targeting aerobic and mixed infections with narrower-spectrum regimens unless specific anaerobic conditions exist. Such an approach can reduce adverse drug effects and antimicrobial resistance pressure, particularly in frail or polymedicated older adults.

Non-pharmacologic treatment approaches remain vital (Bowerman et al., 2018). Postural management, swallowing rehabilitation, and nutritional optimization are essential components of comprehensive care (Marín-Corral et al., 2020). Some studies explored the role of feeding-tube placement, but the evidence remains equivocal. In many cases, percutaneous feeding tubes do not reduce aspiration events and may even increase mortality, emphasizing the need for individualized decision-making and multidisciplinary involvement.

Prevention Strategies and Interdisciplinary Care

Among all aspects reviewed, preventive interventions yielded the most consistent and clinically meaningful outcomes. Evidence supports routine dysphagia screening for at-risk patients, particularly those with acute stroke, dementia, or Parkinson’s disease (Osorio et al., 2024; Park et al., 2020). Studies such as Chen et al. (2021) and Lisiecka et al. (2024) demonstrated that systematic screening followed by early swallowing therapy significantly reduced pneumonia rates. Similarly, Santos et al. (2021) showed that structured oral hygiene programs in nursing homes decreased pneumonia incidence by nearly one-third.

Preventive care is most effective when delivered by interdisciplinary teams. Integration of nursing, speech therapy, nutrition, and dentistry within care pathways enhances adherence and sustainability (Mitchell et al., 2019; Nasreddine and Dauby, 2019). Organizational factors—including staff education, workload, and resource availability—strongly influence outcomes. The reviewed studies also emphasize the importance of family education and the promotion of oral health as part of comprehensive geriatric assessment (Santos et al., 2023).

Such results align with global recommendations from geriatric and pulmonary societies advocating for holistic care that extends beyond pharmacologic management. Preventive strategies are cost-effective, feasible, and directly reduce mortality and hospitalization rates. Yet, widespread implementation remains limited by logistical barriers and inadequate training across healthcare settings.

Integration with Clinical Guidelines and Policy

Current guidelines from the IDSA/ATS (Bernstein, 2019) and the British Thoracic Society (Simpson et al., 2023) provide limited, sometimes conflicting, recommendations specific to aspiration pneumonia. Most extrapolate from data on community- or hospital-acquired pneumonia, resulting in a lack of tailored protocols. This review reinforces the need for distinct diagnostic and treatment frameworks addressing the unique pathophysiology and patient profile of aspiration pneumonia.

Policy-level interventions should prioritize training in dysphagia recognition and oral care, inclusion of speech–language pathology in acute care teams, and establishment of standardized care bundles for aspiration prevention. In long-term care facilities, routine oral assessments, dietary modifications, and head-of-bed elevation protocols should become institutional policy. Integrating these measures into accreditation and quality indicators could meaningfully reduce aspiration-related morbidity.

Conclusions

Aspiration pneumonia continues to represent a complex, multifactorial condition bridging infectious disease, geriatrics, neurology, and rehabilitation medicine. The evidence synthesized in this review underscores that while microbial and pharmacologic aspects are important, prevention through functional, nutritional, and oral health optimization remains the cornerstone of management. The persistence of aspiration pneumonia despite decades of research reflects its embeddedness within broader issues of aging, frailty, and healthcare delivery.

Data support several practical recommendations. Clinicians should maintain a high index of suspicion for dysphagia in all older or neurologically impaired patients and institute early, standardized screening. Oral hygiene must be integrated into daily nursing care and supported institutionally as a preventive priority. Antibiotic therapy should align with current evidence—short in duration, targeted to aerobic and mixed flora, and limiting anaerobic coverage only when clinically indicated. These measures not only improve patient outcomes but also advance antimicrobial stewardship goals.

From a systems perspective, the management of aspiration pneumonia requires coordination across disciplines. Speech–language pathologists, dietitians, nurses, and dental professionals should collaborate within structured care pathways. Training programs must emphasize aspiration risk recognition, swallowing physiology, and early rehabilitation. Healthcare administrators and policymakers can further support this effort by embedding aspiration prevention indicators into quality metrics and reimbursement frameworks.

The shift toward a holistic understanding of aspiration pneumonia also invites exploration of new frontiers. The emerging role of the respiratory microbiome, the interface between inflammation and neurodegeneration, and the impact of sarcopenia and nutrition warrant deeper investigation. Technological innovations—such as bedside ultrasonography for swallowing assessment, tele-rehabilitation, and AI-driven screening algorithms—may enhance early detection and patient engagement.

In summary, aspiration pneumonia is both a preventable and manageable condition when approached comprehensively. The synthesis presented here provides an evidence-based foundation for improving clinical practice, informing policy, and guiding future research. The convergence of multidisciplinary prevention, precise diagnosis, and rational antibiotic use holds the greatest promise for reducing the global burden of aspiration pneumonia in the years ahead.

Limitations and future directions

The collective evidence remains constrained by several methodological limitations. First, heterogeneity in study design and outcome reporting prevented quantitative pooling. Many studies were retrospective, single-center, and lacked standardized definitions, which limits generalizability. Second, publication bias may overrepresent positive interventions, while null or negative findings remain underreported. Third, the restriction to English-language publications may have excluded relevant studies from non-English databases. Finally, the absence of protocol registration and variability in quality appraisal tools among included studies underscores the need for greater methodological rigor in future reviews.

Future research should adopt multidimensional frailty and nutritional status measures to clarify these relationships, and move beyond descriptive studies toward interventional and mechanistic investigations. Key priorities include:

  • Standardized diagnostic criteria distinguishing aspiration pneumonia from pneumonitis.
  • Validated dysphagia screening tools for non-stroke populations.
  • Integration of microbiome profiling to elucidate pathogen–host interactions (Vallianou et al., 2023).
  • Randomized controlled trials evaluating preventive care bundles and short-course antibiotic protocols. (Yoshimatsu et al., 2023).
  • Long-term outcome studies assessing functional recovery and quality of life (Santos et al., 2021; Yoon et al., 2019).

Multicenter collaborations and registries could enable large-scale data collection, improving precision in estimating incidence, microbial patterns, and outcomes across care settings.

Competing interests

The authors declare no competing interests.

Ethics Committee Approval

Ethical approval was not required for this study because it is based exclusively on previously published literature. The research adhered to the ethical guidelines of the Medical University of Tirana to ensure the integrity and validity of the analysis.

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