Aspiration pneumonia in older people

1. Aspiration pneumonia in older people David J Stott David Cargill Professor of Geriatric Medicine

2. Aspiration pneumonia in older people • Epidemiology • Causes of aspiration pneumonia • Oropharyngeal dysphagia • Cerebrovascular and degenerative neurological disease • Oropharyngeal bacterial colonisation / poor oral health • Issues of older age • ‘Physiology’ of ageing • Multimorbidity • Undernutrition • Reduced functional and cognitive reserve • Non-specific presentation of disease • Prevention • Management

3. Conflict of interest Research funding from pharmaceutical industry – Trials of statins, antithrombotics, nutritional supplements Consultancy – Nestle Nutrition, Pfizer, Astra Zeneca

4. Epidemiology • Incidence of pneumonia increases with aging and frailty • RR=6 if age > 75 compared to < 60 years • hospitalisations per year for pneumonia 1.1 / 1000 community-dwelling elderly adults 33 / 1,000 nursing home residents per year • Morbidity and mortality from pneumonia increases with aging Marik, Chest 2003

5. Definitions and mechanisms • Aspiration is the misdirection of oropharyngeal or gastric contents into the larynx and lower respiratory tract • Aspiration pneumonia develops after aspiration of bacterially colonized oropharyngeal contents • Aspiration of bacteria from oropharynx is the primary pathway by which bacteria gain entrance to the lungs

6. Bacterial cause of community- acquired pneumonia (CAP) • Diagnosis of the bacterial cause of CAP is made in <50% • Particular problem in frail elderly patients, often unable to produce adequate sputum specimens • Higher prevalence of Gram-negative pathogens and Staph aureus in elderly patients with CAP • Presumably due to oropharyngeal colonization with subsequent aspiration • Strep pneumoniae remains the single most common implicated pathogen in elderly patients • Unclear if patients with dysphagia are at risk of acquiring pneumococcal pneumonia

7. Health-care associated pneumonia

8. Risk factors - pneumonia in older people • Community dwelling • ‘Silent’ aspiration in 71% of patients with CAP compared to 10% in controls • Residents of long-term care facilities • Difficulty swallowing food (OR 2.0) and medication (OR 8.3)‏ • Witnessed aspiration • Sedative medicines

9. Protection against aspiration • Preserved swallow or cough reflex are important defenses against oropharyngeal aspiration • Impaired swallow / cough increase risk of aspiration pneumonia • Approximately half of all healthy adults aspirate small amounts of oropharyngeal secretions during sleep, most have no sequelae • low bacterial burden of normal pharyngeal secretions • coughing • active ciliary transport • normal humoral and cellular immune mechanisms

10. Functional neuroanatomy of voluntary swallowing – regional CBF / PET • Increase in rCBF over large-scale distributed neural network • L+R inferior pre-central gyrus • R anterior insula • L cerebellum • Putamen, thalamus, several cortical areas Zald, Ann Neurol 1999;46:281

11. Dementia prevalence (%) by age (yrs)

13. Nosocomial pneumonia occurs in up to 40% of acute stroke patients

14. Dysphagia after stroke • Difficulty with / inability to swallow • 50% of acute stroke patients have clinical dysphagia • Most (80%) resolve in the first 7-10 days • Associates with big strokes, aphasia • Increased risk of pneumonia Mann et al, Stroke 1999; 30:744

15. Poor oral health + oropharyngeal bacterial colonisation after stroke Can’t do oral hygiene! • Reduced conscious level • Impaired hand / arm function Can’t ask for oral hygiene! • Communication barriers • Dysphasia • Delirium • Dementia Increased oral vulnerability • Dysphagia • Xerostomia • Nil by mouth • Drugs • Nutritional supplements

16. Associated problems Poor oral health Chronic physical disability Cognitive decline and dementia Sensory impairment Hearing, vision Acute illness Mechanisms Common risk factors Cigarettes, alcohol, socio-economic status, low education Two-way relationship Poor oral health → systemic illness Systemic illness → poor oral health Poor oral health in older people is often associated with other problems

17. Dentures (%)‏ 53% No teeth or dentures (%)‏ 15% Oral cavity score (median + IQR)‏ 10 (8, 13)‏ Xerostomia (%)‏ (<1uL/min salivary flow)‏ 61% The mouth after acute stroke Sellars, Stott et al, Stroke 2007; 38:2284

18. Oral bacterial and fungal flora % acute stroke patients Kerr, Sweeney, Bagg, Stott et al, Cerebrovascular Diseases; 2010

19. Independent predictors (Binary logistic regression)‏ Age > 65 years Dysarthria or aphasia Severe disability modified Rankin > 4 Cognitive impairment Abbreviated Mental Test < 8 Failed water swallow test Predictors of post-stroke pneumonia Univariate predictors not significant on multivariate analysis • Poor oral health • Oral bacterial colonisation • COPD Sellars, Stott et al, Stroke 2007; 38: 2284

20. Swallowing assessment and investigation after stroke Routine assessment • Look in the mouth! No impaired consciousness • Water swallow test • Bedside swallow assessment Selected patients • Nasendoscopy • Modified Barium swallow (video-fluoroscopy)

21. Key concepts in illness in later life • Reduced homeostatic reserve with ageing • Multiple diseases • Frailty • Undernutrition • Iatrogenesis, adverse drug reactions • Non-specific presentation of disease • Geriatric giants • Multiple problems, requiring complex solutions

22. FVC and FEV1 and ageing Knudson, Am Rev Resp Dis 1976

23. Healthy ageing and the swallow • Older people swallow more slowly • Laryngeal vestibule closure delayed • Maximal hyolaryngeal excursion delayed • Upper esophageal sphincter opening delayed • Oral bolus transport time prolonged • Safety of oropharyngeal swallowing is not compromised • No increase in the frequency of aspiration in radiographic studies that compare older to younger adults • However reduced physiological reserve

24. Cough reflex –respiratory defence • No apparent effect of healthy ageing on the cough reflex • The cough threshold concentration for inhaled citric acid • 2.6 ± 4.0 mg/mL in control subjects • 37.1 ± 16.7 mg/mL in patients with dementia • > 360 mg/mL in survivors of aspiration pneumonia

25. Geriatric Giants – non-specific presentation of disease • Intellectual impairment • Delirium and dementia • Immobility • ‘Off feet’ • Instability • Falls • Incontinence • Loss of swallow

26. Fernandez-Sabe et al Medicine 2003; 82:159 • 1,474 patients hospitalized with CAP • nursing home residents excluded • 305 (21%) over 80 years versus under 80s • pleuritic chest pain reduced (37 versus 45%) • headache (7 versus 21%) • myalgias (8% versus 23%) • absence of fever (32% versus 22%) • ‘altered mental status’ (21 versus 11%)

27. Cumulative incidence of delirium in hospitalised patients Cochrane Database of Systematic Reviews

28. Causes of delirium O'Keefe & Lavan, Age Ageing 1999;28: 115

29. Outcome of delirium • Prolonged hospital stay • Increased mortality • Increased costs of health care • Residual cognitive impairment • Increased risk of progression to dementia

30. Management strategies to reduce the risk of aspiration pneumonia • Assistance with regular oral hygiene • Screening / investigation for dysphagia • High risk subgroups e.g. stroke, dementia, pneumonia, witnessed aspiration • Nil-by-mouth during high risk periods • Postural interventions / swallowing manoeuvres for dysphagia • Hand-feeding • Small amounts frequently • Modified diet / thickened fluids / food supplements

31. Conclusions • Aspiration is the main cause of pneumonia in later life • Oropharyngeal dysphagia plus bacterial colonisation • Frailty, cognitive impairment and multi-morbidity • Non-specific presentation • Potential for prevention • multi-modal / multi-disciplinary strategies

32. Funders CSO Scottish Executive Chest Heart and Stroke Scotland Acknowledgements Collaborators • Petrina Sweeney • Jeremy Bagg • Gillian Kerr • Marian Brady • Cameron Sellars • Lindsay Bowie • Peter Langhorne