Oral Clearance and Pathogenic Oropharyngeal Colonization in the Elderly

Abstract

The elderly have an increased incidence of oropharyngeal colonization with respiratory pathogens, a well-known risk factor for the development of pneumonia. Changes in the oral milieu may occur secondary to decreased salivary production and abnormalities in swallowing. These abnormalities, common in the elderly, may result in impaired clearance of organisms, allowing pathogenic colonization. To test this hypothesis, we performed a prospective cross-sectional analysis of 75 elderly institutionalized patients and measured oral clearance using (99m)Tc-human serum albumin (HSA) administered to the oropharynx. Oropharyngeal cultures, salivary cell populations, elastase activity, and clinical parameters were measured simultaneously. Retention of radiolabel ranged from 100% to 2.3% over 120 min of observation. Clearance in the oropharynx was significantly decreased in those patients who had oropharyngeal colonization with gram-negative bacilli (GNB), Staphylococcus aureus (SA), or yeast compared with those demonstrating normal flora by 95% confidence intervals. Decreased clearance was also seen in patients on antidepressants by 95% confidence levels. The absolute number of salivary lymphocytes/ml and buccal cells/ml was increased in colonized patients versus noncolonized persons (mean +/- SEM, 128 x 10(3) +/- 49 x 10(3), 25.4 +/- 11.6 x 10(3)). Elastase activity was elevated in patients who had GNB compared with patients without GNB (mean +/- SEM, 10.6 nM +/- 5.7, versus 2.2 nM +/- 1.2, p = 0.036). We conclude that a decrease in salivary clearance of potentially pathogenic organisms may be a major risk factor for the development of colonization in the elderly.

Oropharyngeal dysphagia is a risk factor for community-acquired pneumonia in the elderly

“…The aspiration of small amounts of oropharyngeal secretions during sleep is a common finding in older adults [22,23] and usually happens without consequences due to preserved cough reflex, ciliary transport and immune system and to the low virulence of normal pharyngeal flora. However, the silent aspiration of large amounts during swallowing is an abnormal and serious finding that, together with several factors common in the elderly such as progressive decrease in pulmonary function, decline in host defences, impaired cough reflex and increased oropharyngeal colonisation with respiratory pathogens can lead to aspiration pneumonia [19]. A key point of our study is that we elucidated the pathogenic mechanism of the aspiration process and impaired airway protection of patients with CAP through videofluoroscopy.…”

“…***: p,0.001. pulmonary or oropharyngeal pathogens may colonise the oropharynx and be a potential source of pulmonary infections [19]. TERAMOTO et al [20] reported that the prevalence of aspiration pneumonia in patients with CAP aged o70 years was 60.1%, using a wide variety of clinical assessment methods.…”

Streptococcus pneumoniae Colonization Disrupts the Microbial Community within the Upper Respiratory Tract of Aging Mice

“…Antibacterial immunity is impaired in the elderly due to complex changes in innate and adaptive immunity called immunosenescence (63)(64)(65).…”

The Comparison of the Effect of the Head of Bed Elevation to 30 and 45 Degreess on the Incidence of Ventilator Associated Pneumonia and the Risk for Pressure Ulcers: A Controlled Randomized Clinical Trial

“…The prevention of VAP reduces the duration of mechanical ventilation, length of hospital stay, mortality, and healthcare costs (10). Another preventive method in patients undergoing mechanical ventilation is raising HOB to 30 degrees or more (11). According to clinical guidelines related to the prevention of pneumonia and aspiration, HOB should be elevated to 30 -45 degrees among mechanically ventilated patients (12).…”