Oral clearance and pathogenic oropharyngeal colonization in the elderly

Hyposalivation and xerostomia in dentate older adults

BACKGROUND

Older adults are susceptible to reduced saliva production related to certain medications, radiation and chronic conditions. Many of these people have many physical and oral health problems and limited access to dental care. The use of effective screening tools for xerostomia and hyposalivation would be helpful in identifying those at risk. The authors conducted a study to investigate the association between three measures of oral dryness: hyposalivation (low unstimulated salivary flow), self-reported xerostomia and clinically assessed dry mouth.

METHODS

The authors included a convenience sample of 252 nondemented and dentate West Virginia participants 70 years and older who were part of a larger study on oral health and cognition among older adults. Participants completed a self-reported xerostomia index, provided an unstipulated salivary sample and underwent an oral assessment for the study.

RESULTS

Twenty-eight participants (11.1 percent) had hyposalivation, eight of whom reported having xerostomia (sensitivity=28.6 percent). Of the 43 participants who reported having xerostomia, only eight had hyposalivation (positive predictive value=18.6 percent). Hyposalivation and self-reported xerostomia were not significantly related. Clinically assessed dry mouth correlated modestly, but significantly, with hyposalivation and self-reported xerostomia.

CONCLUSIONS

Obtaining routine unstimulated salivary flow rates in addition to self-reported information and oral evaluations may increase early detection of oral dryness, which would assist in implementing early interventions to improve patients' quality of life.

CLINICAL IMPLICATIONS

Visually inspecting oral tissues for dryness and asking a patient if his or her mouth is dry are insufficient measures for clinicians to use to determine if the patient has hyposalivation. The authors recommend that clinicians determine the patient's unstimulated salivary flow rate.

[Swallowing disorders, pneumonia and respiratory tract infectious disease in the elderly]

Swallowing disorders (or dysphagia) are common in the elderly and their prevalence is often underestimated. They may result in serious complications including dehydration, malnutrition, airway obstruction, aspiration pneumonia (infectious process) or pneumonitis (chemical injury caused by the inhalation of sterile gastric contents). Moreover the repercussions of dysphagia are not only physical but also emotional and social, leading to depression, altered quality of life, and social isolation. While some changes in swallowing may be a natural result of aging, dysphagia in the elderly is mainly due to central nervous system diseases such as stroke, parkinsonism, dementia, medications, local oral and oesophageal factors. To be effective, management requires a multidisciplinary team approach and a careful assessment of the patient's oropharyngeal anatomy and physiology, medical and nutritional status, cognition, language and behaviour. Clinical evaluation can be completed by a videofluoroscopic study which enables observation of bolus movement and movements of the oral cavity, pharynx and larynx throughout the swallow. The treatment depends on the underlying cause, extent of dysphagia and prognosis. Various categories of treatment are available, including compensatory strategies (postural changes and dietary modification), direct or indirect therapy techniques (swallow manoeuvres, medication and surgical procedures).

Infection in the elderly

Many functional, demographic, and immunologic changes associated with aging are responsible for increasing the incidence and severity of infectious diseases in the elderly. Management is complicated by age-related organ system changes. Because many of the elderly are on multiple medications for underlying illnesses, antimicrobial therapy needs to be chosen keeping drug interactions and adverse events in mind. Common infections seen in the elderly are infections of skin and soft tissue, urinary tract, respiratory tract, and gastrointestinal tract. Organized and well-funded programs to address infectious disease issues in the elderly are the only way to improve care.

Bacterial community-acquired pneumonia in older patients

Pneumonia in the elderly remains a major source of morbidity and mortality in an age group that is growing in numbers. It remains unclear whether the propensity of older adults to develop community-acquired pneumonia represents an aging of host defenses, secondary effects of comorbid disease, or both. The signs and symptoms of pneumonia in the elderly are more subtle than in younger populations, which may lead to a delay in diagnosis. Although therapy for community-acquired pneumonia in the elderly is the same as for younger populations, mortality is higher, leading to an important role for prevention.

Aspiration pneumonias: under-diagnosed and under-treated

PURPOSE OF REVIEW

To examine recent advancements of the epidemiology, risk factors, bacteriology, diagnostic measures, and treatment for aspiration pneumonia.

RECENT FINDINGS

In a large prospective study, 10.3% of community-acquired pneumonia requiring hospitalization was associated with aspiration pneumonia, as opposed to 30% when patients were admitted from long-term facilities. A murine stroke model showed increased apoptosis of cell-mediated immune cells due to overactivation of the sympathetic nervous system. Subsequent nasal inoculum of low-dose Streptococcus pneumoniae caused severe pneumonia. Another murine study showed intratracheal administration of hydrochloric acid-primed lungs more susceptible to infection with Klebsiella pneumoniae. Tracheal pH monitoring demonstrated acidification of trachea in 28% of patients with acute stroke deemed to be safe for oral feeding. Various antimicrobial agents used to treat aspiration pneumonia have comparable success rates. However, clindamycin was the only agent that did not propagate emergence of methicillin-resistant Staphylococcus aureus.

SUMMARY

Aspiration pneumonia is prevalent in community-acquired pneumonia. Further studies are needed to elucidate the effects of sympathetic nervous system and aspiration pneumonitis as primers for lung infection. Predicting aspiration risk is difficult and newer diagnostic tools are necessary. Antimicrobials used in aspiration pneumonia have similar success rates although the development of resistant organisms must be monitored.

Effect of inhaled budesonide on oropharyngeal, Gram-negative bacilli colonization in asthma patients

BACKGROUND AND OBJECTIVE

The effect of inhaled budesonide on oropharyngeal Gram-negative bacilli colonization (OGNBC) in asthmatic patients was investigated.

METHODS

Oropharyngeal cultures were obtained from asthmatic patients attending the hospital respiratory outpatient clinic, at baseline and 1 month after treatment with 800 microg/day of inhaled budesonide. Cultures were evaluated for OGNBC and compared with those of healthy controls.

RESULTS

A total of 148 cultures (74 from asthma patients, 74 from healthy controls) were evaluated. Six cultures (8.1%) from healthy controls, eight cultures (10.8%) from asthma patients obtained before treatment and 20 cultures (27.0%) obtained after treatment were positive for OGNBC (P < 0.05). Gender, age, presence of atopy and the degree of illness were not found to be related to the presence of OGNBC in and healthy control cultures. In the cultures obtained from the patients after treatment, OGNBC was higher in patients >50 years and in those with FEV1 < 70% (P < 0.05). Nine (18.8%) of 48 patients <50 years compare with 11 (42.3%) of the 26 patients >50 revealed OGNBC (P < 0.05). OGNBC were observed in 18.9% of the patients with FEV1 = 70% and in 47.6% of those with FEV1 < 70% (P < 0.05).

CONCLUSIONS

The increased rate of OGNBC in asthma patients treated with inhaled budesonide was found to be related to increased age and lower level of FEV1. Further studies with larger numbers of patients are required for the interpretation of this colonization in the course of lower respiratory infections in these patients.

An unusual cause of aspiration pneumonia

We report a case of aspiration admitted to our rehabilitation unit in a patient with dysphagia due to diffuse idiopathic skeletal hyperostosis or Forestier's disease of the cervical spine, in whom an episode of pneumonia had occurred. Clinical and instrumental findings, including radiography of the spine, (CT Scan) and videofluoroscopy, confirmed the diagnosis. The dysphagia was hypothesized to be due to mechanical compression and inflammatory changes, accompanied by fibrosis in the esophagus wall. The aspiration pneumonia probably had multifactorial etiology: dysphagia, abnormal cough reflex, colonization of the oropharynx by virulent bacteria, etc. No aspiration pneumonia occurred after medical treatment and rehabilitation had been started. We review the medical literature on this unusual cause of aspiration pneumonia.

Effect of various antibacterial preparations on the pathogenic oral flora in elderly patients fed via nasogastric tube

Oropharyngeal colonization by pathogenic gram-negative bacilli (GNB) and Staphylococcus aureus is associated with aspiration pneumonia. Decolonization in high-risk populations may be important. We prospectively evaluated six antiseptic compounds in nasogastric tube-fed frail elderly patients; only polymixine reduced oropharyngeal colonization with GNB. None had an effect on S. aureus colonization.

Pneumonia in the Nursing Home

Pneumonia syndromes may be caused by infection or the aspiration of food, acid, or particulate material. Antibiotic-resistant organisms or recurrent aspiration should be considered if the response to treatment is poor. Clinicians should consider discontinuing antibiotics if the resident's status rapidly returns to baseline after a noninfectious macro-aspiration event. The natural history of this process, however, is not well characterized. Diagnostic procedures including sputum gram stain, culture, and urinary antigen testing should be pursued to diagnose pathogens not covered by empiric therapy or to focus therapy with narrow spectrum agents. Sources of aspiration, including pharyngeal dysphagia, periodontal disease, and gastric regurgitation, should be identified and treated in hopes of preventing recurrence.

Aspiration and infection in the elderly : epidemiology, diagnosis and management

Aspiration of the oropharyngeal or gastric contents by elderly persons often leads to lower respiratory tract infections, such as aspiration pneumonia or pneumonitis. The existence of dysphagia and aspiration in elderly patients are important factors in the occurrence of aspiration pneumonia, but are not sufficient to cause aspiration pneumonia in the absence of other risk factors. Salivary flow and swallowing can eliminate Gram-negative bacilli from the oropharynx in healthy persons. However, elderly persons may have diminished production of saliva as a result of medications and oral/dental disease, leading to poor oral hygiene and oropharyngeal colonisation with pathogenic organisms. When dysphagic patients aspirate pathogenic bacteria while swallowing food or liquids, they must also have decreased defences, such as impaired immunity or pulmonary clearance, in order to develop aspiration pneumonia.Elderly patients with cerebrovascular disease often have dysphagia that leads to an increased incidence of aspiration. It was previously reported that patients with silent cerebral infarction affecting the basal ganglia were more likely to experience subclinical aspiration and an increased incidence of pneumonia. Basal ganglia infarction leads to the impairment of dopamine metabolism and, as a consequence, a decrease of substance P in the glossopharyngeal nerve and sensory vagal nerves. Therefore, dysphagia and a decreased cough reflex may be induced by the impairment of dopamine metabolism in some elderly patients with cerebrovascular disease, suggesting that pharmaceutical agents which modulate dopamine metabolism may be able to improve swallowing and the cough reflex in patients with basal ganglia infarction. The main strategy for controlling aspiration and aspiration-related pulmonary infection in the elderly is to prevent aspiration of pathogenic bacteria along with the oropharyngeal or gastric contents. Because aspiration pneumonia in the elderly is related to certain risk factors, including dysphagia and aspiration, effective preventive measures involve various approaches, such as pharmacological therapy, swallowing training, dietary management, oral hygiene and positioning.

Can We Prevent Aspiration Pneumonia in the Nursing Home?

Aspiration pneumonia is a significant cause of morbidity, hospitalization, and mortality in the nursing home population. Patients who aspirate have three times higher mortality than patients who do not aspirate. We discuss the factors known to increase the risk of aspiration and its consequences, and recognize some of the preventive measures for aspiration pneumonia. We suggest approaches to decrease the risk of this very prevalent syndrome.

Effects of an Angiotensin-converting Enzyme Inhibitor–based Regimen on Pneumonia Risk

Observational studies conducted among Asian populations suggest that the risk of pneumonia is substantially reduced among users of angiotensin-converting enzyme (ACE) inhibitors but not other blood pressure-lowering agents. We conducted analyses of the effects of ACE inhibitor therapy on pneumonia in 6,105 patients with a history of stroke or transient ischemic attack enrolled in a randomized trial conducted in Australasia, Europe, and Asia. Patients were randomly assigned perindopril-based active treatment or placebo. The effects of ACE inhibitors on pneumonia (fatal or nonfatal) were determined from Cox models fitted according to the principle of intention to treat. During a median follow-up of 3.9 years, 261 patients developed pneumonia. Overall, active treatment was associated with a nonsignificant 19% lower risk of pneumonia (95% confidence interval, -3 to 37; p = 0.09) compared with placebo. Active treatment significantly reduced the risk of pneumonia among participants of Asian ethnicity (47%, 14-67%; p = 0.01), with no significant effect among non-Asian participants (5%, -27 to 29%; p = 0.7) (p for homogeneity = 0.04). These findings substantially add to the body of evidence about the effects of these drugs on pneumonia but do not provide the definitive information required to inform clinical decisions about the prevention of pneumonia with ACE inhibitors.

Pneumonia in the very old

Pneumonia is a major medical problem in the very old. The increased frequency and severity of pneumonia in the elderly is largely explained by the ageing of organ systems (in particular the respiratory tract, immune system, and digestive tract) and the presence of comorbidities due to age-associated diseases. The most striking characteristic of pneumonia in the very old is its clinical presentation: falls and confusion are frequently encountered, while classic symptoms of pneumonia are often absent. Community-acquired pneumonia (CAP) and nursing-home acquired pneumonia (NHAP) have to be distinguished. Although there are no fundamental differences in pathophysiology and microbiology of the two entities, NHAP tends to be much more severe, because milder cases are not referred to the hospital, and residents of nursing homes often suffer from dementia, multiple comorbidities, and decreased functional status. The immune response decays with age, yet pneumococcal and influenza vaccines have their place for the prevention of pneumonia in the very old. Pneumonia in older individuals without terminal disease has to be distinguished from end-of-life pneumonia. In the latter setting, the attributable mortality of pneumonia is low and antibiotics have little effect on life expectancy and should be used only if they provide the best means to alleviate suffering. In this review, we focus on recent publications relative to CAP and NHAP in the very old, and discuss predisposing factors, microorganisms, diagnostic procedures, specific aspects of treatment, prevention, and ethical issues concerning end-of-life pneumonia.

Lung infections and aging

Respiratory tract infections are the leading cause of death due to infectious disease in the elderly. Many factors, especially waning immune responses and the onset of age-associated organ dysfunction, likely account for an increase in susceptibility to respiratory tract infection in the elderly, and morbidity and mortality rates are substantially greater for the elderly when outcomes are compared to that of younger individuals. The presence of underlying disease states such as chronic obstructive pulmonary disease (COPD) or other organ system disease further increases the likelihood of developing severe pneumonia in the elderly population, and the frail elderly, particularly when institutionalized in chronic care facilities, are at high risk for developing severe and recurrent pneumonia. This article will discuss various factors associated with advanced age that predispose the elderly to respiratory infections and summarize current approaches to treatment and prevention.

The incidence of oral Gram-negative bacteria in patients with Parkinson's disease

Background: Parkinson's disease is a common neurodegenerative disorder that affects an increasing number of older people every year. Dysphagia is not only a common feature, but one that results in poor nutrition and an increased risk of bronchopneumonia. Previous work has suggested that the oral flora is altered in patients with oral pathology. Methods: Fifty patients were assessed to quantify the incidence of oral Gram-negative bacteria. Results: Sixteen of the patients with Parkinson's disease were found to have six different Gram-negative bacilli in their oral cavities. The 20 different Gram-negative bacteria present were Escherichia coli (n=7), Klebsiella spp. (n=3), Kluyvera spp. (n=3), Serratia spp. (n=3), Proteus spp. (n=2) and Enterobacter spp. (n=2). We found that the oral cavity of 16 (32%) of the patients with Parkinson's disease was abnormally colonised with Gram-negative bacteria and that Gram-negative bacteria were more likely to occur in those patients in whom oromuscular dysfunction was present (88% vs. 21%; p<0.05). Conclusion: Further work is required to determine the association between oral flora and the pathogenic organisms found in aspiration pneumonia as well as work on innovative treatments to reduce oral Gram-negative bacteria in those patients at particular risk of aspiration pneumonia.

Pseudomonas aeruginosa and the oropharyngeal ecosystem of tube-fed patients

We evaluated whether elderly patients fed with nasogastric tubes (NGT) are predisposed to Pseudomonas aeruginosa colonization in the oropharynx. Fifty-three patients on NGT feeding and 50 orally fed controls with similar clinical characteristics were studied. The tongue dorsum was swabbed and cultured. P. aeruginosa was isolated in 18 (34%) of the NGT-fed group but in no controls (p<0.001). Other gram-negative bacteria were cultured from 34 (64%) of NGT-fed patients as compared with 4 (8%) of controls (p<0.001). Antibiotic susceptibility of the oropharyngeal P. aeruginosa isolates was compared with that of isolates from sputum cultures obtained from our hospital's bacteriologic laboratory. The oropharyngeal isolates showed a higher rate of resistance; differences were significant for amikacin (p<0.03). Scanning electron microscope studies showed a biofilm containing P. aeruginosa organisms. The pulsed-field gel electrophoresis profile of these organisms was similar to that of P. aeruginosa isolates from the oropharynx. NGT-fed patients may serve as vectors of resistant P. aeruginosa strains.

Aspiration pneumonia and dysphagia in the elderly

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality in the elderly, and the leading cause of death among residents of nursing homes. Oropharyngeal aspiration is an important etiologic factor leading to pneumonia in the elderly. The incidence of cerebrovascular and degenerative neurologic diseases increase with aging, and these disorders are associated with dysphagia and an impaired cough reflex with the increased likelihood of oropharyngeal aspiration. Elderly patients with clinical signs suggestive of dysphagia and/or who have CAP should be referred for a swallow evaluation. Patients with dysphagia require a multidisciplinary approach to swallowing management. This may include swallow therapy, dietary modification, aggressive oral care, and consideration for treatment with an angiotensin-converting enzyme inhibitor.

Microbiology of severe aspiration pneumonia in institutionalized elderly

We sought to investigate prospectively the microbial etiology and prognostic indicators of 95 institutionalized elders with severe aspiration pneumonia, and to investigate its relation to oral hygiene in using quantitative bronchial sampling. Data collection included demographic information, Activity of Daily Living, Plaque Index, antimicrobial therapy, and outcome. Out of the 67 pathogens identified, Gram-negative enteric bacilli were the predominant organisms isolated (49%), followed by anaerobic bacteria (16%), and Staphylococcus aureus (12%). The most commonly encountered anaerobes were Prevotella and Fusobacterium species. Aerobic Gram-negative bacilli were recovered in conjunction with 55% of anaerobic isolates. The Plaque Index did not differ significantly between the aerobic (2.2 +/- 0.4) and the anaerobic group (2.3 +/- 0.3). Functional status was the only determinant of the presence of anaerobic bacteria. Although seven cases with anaerobic isolates received initially inadequate antimicrobial therapy, six had effective clinical response. The crude mortality was 33% for the aerobic and 36% for the anaerobic group (p = 0.9). Stepwise multivariate analysis identified hypoalbuminemia (p < 0.001) and the burden of comorbid diseases (p < 0.001) as independent risk factors of poor outcome. In view of the rising resistance to antimicrobial agents, the importance of adding anaerobic coverage for aspiration pneumonia in institutionalized elders needs to be reexamined.

Pathogenic colonization of oral flora in frail elderly patients fed by nasogastric tube or percutaneous enterogastric tube

BACKGROUND

Aspiration of infected oropharyngeal content is the main cause of aspiration pneumonia. This complication, mainly related to gram-negative bacteria, threatens percutaneous enterogastric tube as well as nasogastric tube (NGT) fed patients. The objective of this study was to examine the oral microbiota of tuboenterally fed patients and compare it with that of orally fed counterparts.

METHODS

Patients were recruited for this study from six nursing and skilled nursing facilities with an overall number of 845 beds. Enrolled were 215 patients: Group 1 consisted of 78 patients on NGT feeding, Group 2 consisted of 57 patients on percutaneous enterogastric tube feeding, and Group 3 consisted of 80 patients fed orally who were from the same facilities. Cultures were performed by sampling the oropharynx of each subject in order to identify gram-negative bacteria and Staphylococcus aureus.

RESULTS

A high prevalence of potentially pathogenic isolations was found in tuboenterally fed patients: 81% in Group 1 and 51% in Group 2, as compared with only 17.5% in Group 3 (p <.0001). Pseudomonas aeruginosa was cultured from 31% of the subjects in Group 1 and 10% of Group 2, but in none of Group 3 (p <.001). Klebsiella and Proteus were isolated mainly from the NGT fed patients (p <.003). No correlation was found between the time duration on tube feeding or the presence of residual dentition and pathogenic microbiota.

CONCLUSION

This study shows that tuboenteral feeding in elderly patients is associated with pathogenic colonization of the oropharynx. These findings are related to the risk of aspiration pneumonia and are compelling for the reevaluation of current oral cleansing procedures.

Impact of invasive strategy on management of antimicrobial treatment failure in institutionalized older people with severe pneumonia

The aim of the study was to investigate the etiology and the impact of invasive quantitative sampling on the management of severe pneumonia in institutionalized older people with antimicrobial treatment failure. Fifty-two institutionalized patients aged 70 years and older hospitalized with a presumptive diagnosis of severe pneumonia and failure to respond to treatment after 72 hours of initiation of outpatient antimicrobial therapy were enrolled. Microbial investigation included blood culture, serology, pleural fluid, and bronchoalveolar samples. A definite etiology could be established in 24 of 52 (46%) patients. Methicillin-resistant Staphylococcus aureus (33%), enteric Gram-negative bacilli (24%), and Pseudomonas aeruginosa (14%) accounted for most isolates. Atypical infections (2%) were uncommon. Invasive bronchial sampling directed a change of microbial therapy in 8 (40%) and discontinuation of antibiotics in 2 of 20 cases (10%) of definite pneumonia. Overall hospital mortality was 42%. There was no difference in mortality among definite or unverified cases or those who had invasive bronchial sampling-guided change in therapy. We conclude that antimicrobial therapy should be targeted toward "nosocomial" pathogens in those institutionalized patients who received prior antibiotic treatment. When combined with microbial investigation, direct visualization of the tracheobronchial tree might be useful in determining the presence of bacterial pneumonia.