High incidence of silent aspiration in elderly patients with community-acquired pneumonia

Fatores de risco e medidas profiláticas nas pneumonias adquiridas na comunidade

Este artigo revisa os efeitos do envelhecimento, tabagismo, DPOC, insuficiência cardíaca, colonização da orofaringe, aspiração (micro e macro), alcoolismo, cirrose hepática, deficiência nutricional, imunossupressão e fatores ambientais sobre o risco de adquirir pneumonia na comunidade e sua gravidade. Na segunda parte, é feita revisão sobre a ação profilática das vacinas antiinfluenza e antipneumococo, assim como a ação das drogas antivirais, na profilaxia e tratamento das pneumonias adquiridas na comunidade.

Prevalence of potential respiratory pathogens in the mouths of elderly patients and effects of professional oral care

To evaluate the effectiveness of professional oral health care in reducing the risk of aspiration pneumonia, we examined the prevalence of potential respiratory pathogens in gargled samples from elderly persons. Samples were obtained from 54 elderly subjects over 65 years of age who required daily nursing care, from 21 healthy elderly subjects over 65 years old, and from 22 healthy young subjects under 30 as controls. The prevalence of possible pathogens was determined by culture and the polymerase chain reaction. The percentages detected in samples of Streptococcus pneumoniae, Staphylococcus species, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans from elderly patients requiring daily nursing care were 63.0, 37.0, 14.8, 5.6 and 66.7, respectively. The numbers of C. albicans cells recovered in samples from elderly subjects were significantly higher than those recovered from the healthy young group (P<0.001). Elderly patients needing daily care and receiving professional oral health care had lower prevalences and cell numbers of C. albicans than did the elderly patients without such oral care. This study showed that professional oral health care in elderly requiring daily nursing care reduced the cell numbers of potential respiratory pathogens.

Interventions to prevent pneumonia among older adults

Pneumonia is a common cause of death in older people. Antimicrobial drugs do not prevent pneumonia and, because of increasingly resistant organisms, their value in curing infection will become more limited. Establishing new strategies to prevent pneumonia through consideration of the mechanisms of this devastating illness is essential. The purpose of this review is to discuss how pneumonia develops in older people and to suggest preventive strategies that may reduce the incidence of pneumonia among older adults. Aspiration of oropharyngeal bacterial pathogens to the lower respiratory tract is one of the most important risk factors for pneumonia; impairments in swallowing and cough reflexes among older adults, e.g., related to cerebrovascular disease, increase the risk for the development of pneumonia. Thus, strategies to reduce the volumes and pathogenicity of aspirated material should be pursued. For example, since both swallowing and cough reflexes are mediated by endogenous substance P, pharmacologic therapy using angiotensin-converting enzyme inhibitors, which decrease substance P catabolism, may improve both reflexes and result in the lowering of the risk of pneumonia. Similarly, since the production of substance P is regulated by dopaminergic neurons in the cerebral basal ganglia, treatment with dopamine analogs or potentiating drugs such as amantadine (and, of course, prevention of cerebral vascular disease, which can result in basal ganglia strokes) should affect the incidence of pneumonia. The purpose of this review is to consider promising pharmacologic treatments as methods of preventing pneumonia in older adults and to review other proven strategies, e.g., infection control and cerebrovascular disease prevention that will lessen the incidence of pneumonia.

Detection of aspiration and swallowing disorder in older stroke patients: simple swallowing provocation test versus water swallowing test

OBJECTIVE

To assess the sensitivity and specificity of a simple swallowing provocation test (SPT) and a water swallowing test (WST) in detecting aspiration pneumonia in elderly patients with stroke.

DESIGN

Retrospective comparative study involving a simple 2-step SPT and WST on all subjects.

PARTICIPANTS

Twenty-six stroke patients with aspiration pneumonia (mean age, 72.1 +/- 4.1 yr) and 26 age-matched stroke patients without aspiration pneumonia (mean age, 69.4 +/- 3.9 yr).

INTERVENTIONS

The normal response to SPT was determined by inducing swallowing reflex within 3 seconds after water injection into the suprapharynx. In WST, subjects drank quantities of 10 and 30 mL of water from a cup within 10 seconds. The subject who drank water without interruption-without evidence of aspiration-was determined as normal.

RESULTS

The sensitivity and specificity of first-step SPT for the detection of aspiration pneumonia were 100% and 83.8%, respectively. Those of the second-step SPT were 76.4% and 100%, respectively. The sensitivity and specificity of first-step WST using 10 mL of water for the detection of aspiration pneumonia were 71.4% and 70.8%, respectively. Those of the second-step WST using 30 mL of water were 72% and 70.3%, respectively.

CONCLUSION

SPT is more useful than WST in differentiating patients predisposed to aspiration.

Community-acquired pneumonia in the elderly

Pneumonia in the elderly is a common and serious problem with a clinical presentation that can differ from that in younger patients. Older patients with pneumonia complain of significantly fewer symptoms than do younger patients, and delirium commonly occurs. Indeed, delirium may be the only manifestation of pneumonia in this group of patients. Alcoholism, asthma, immunosuppression, and age >70 years are risk factors for community-acquired pneumonia in the elderly. Among nursing home residents, the following are risk factors for pneumonia: advanced age, male sex, difficulty in swallowing, inability to take oral medications, profound disability, bedridden state, and urinary incontinence. Streptococcus pneumoniae is the most common cause of pneumonia among the elderly. Aspiration pneumonia is underdiagnosed in this group of patients, and tuberculosis always should be considered. In this population an etiologic diagnosis is rarely available when antimicrobial therapy must be instituted. Use of the guidelines for treatment of pneumonia issued by the Infectious Diseases Society of America, with modification for treatment in the nursing home setting, is recommended.

The effects of the traditional chinese medicine, "Banxia Houpo Tang (Hange-Koboku To)" on the swallowing reflex in Parkinson's disease

Swallowing disorder is common in Parkinson's disease (PD). We studied the swallowing disorder in PD, and tested the efficacy of Banxia Houpo Tang (BHT, a Chinese traditional medicine) in improving the swallowing reflex of PD patients. The Swallowing reflex test is a simple method used to detect swallowing disorders in patients with cerebrovascular disease. Because we observed previously that BHT significantly improved the swallowing reflex in cerebrovascular patients, we studied whether BHT was also effective in improving the swallowing disorder in patients with PD. 23 PD patients (13 males, 10 females, mean age 66.0+/-9.3, Hoehn & Yahr (H-Y) mean score = 2.8) were evaluated for swallowing reflex and the concentration of substance-P in their saliva before and after 4 weeks of BHT treatment. The swallowing reflex before treatment was significantly delayed, according to the H-Y score (Spearman's p = 0.014, R2 = 0.463). The swallowing reflex before BHT treatment was 3.66+/-0.98 sec, and after BHT treatment, it improved significantly, to 2.27+/-0.54 sec (p < 0.0001). Substance-P concentration in PD patients saliva before treatment was significantly lower than in healthy controls (p = 0.007), but showed no significant change after BHT treatment. Our research shows that the swallowing reflex is an effective method to evaluate the swallowing disorder in PD. BHT can significantly improved the swallowing reflex in PD patients, and therefore can be a hopeful candidate for preventing aspiration pneumonia in PD.

Satisfaction of patients treated surgically for intractable aspiration

STUDY OBJECTIVE

Impaired laryngeal protective function can result in intractable aspiration requiring surgical treatment. There are, however, few reports evaluating the satisfaction of patients and the efficacy of surgical therapy. The purpose of this study is to determine whether surgery for intractable aspiration is beneficial for alleviating depression and improving the mood of patients who have undergone surgical treatment and whether patients and their families are satisfied with the therapy.

PATIENTS AND STUDY DESIGN

Seven patients with recurrent aspiration pneumonia that could not be controlled by appropriate medical therapies participated in the study. These patients had no hope of recovering laryngeal function. Six underwent laryngectomy and one underwent laryngotracheal separation. After surgery, we evaluated the efficacy of the therapy and the patients' satisfaction with the therapy.

METHODS

The following clinical variables concerning surgical procedure were examined: operation time, time until oral intake, videofluorographic study, and surgical complications. The treatment methods including feeding status were also examined before and after surgery. In addition, the following markers were examined to evaluate the efficacy of the surgery: score of aspiration pneumonia, body mass index, total protein, albumin, hematocrit, WBC count, C-reactive protein, erythrocyte sedimentation rate, and the Barthel Index, an indicator of daily activity. Furthermore, the grade of depression and mood, and satisfaction of patients and their caretakers among family members were scored by the Zung self-rating depression scale, a 20-picture face scale, and the visual analog scale.

RESULTS

After surgical therapy, we confirmed by videofluorography that aspiration was completely prevented. No surgical complications occurred. By 18 +/- 6 days, all seven patients were able to ingest a meal orally. The need for extensive medical care and repeated hospitalizations became unnecessary after surgery. The control of pneumonia and albumin improved significantly. The grade of depression and mood of patients and their families also improved significantly. Satisfaction scores of patients receiving therapy were very high.

CONCLUSIONS

Our study shows that surgical therapy to prevent aspiration improves the depression and mood of patients and their families as well as feeding status and clinical outlook. Surgical therapy for patients with intractable aspiration is effective and beneficial.

Combined effects of both bacteria and gastric juice on pneumonia in mice

The effects of a combined inoculation of gastric juice and Streptococcus pneumoniae on the lungs of mice was investigated. Survival rates of mice inoculated with bacteria alone, gastric juice alone, and both bacteria and gastric juice were compared over 18 days. Xanthine oxidase (XO) activities in the lung tissues of mice inoculated with bacteria and gastric juice were measured and injected with a free radical scavenger, pyran-superoxide dismutase (pyran-SOD). A high mortality rate was observed in mice inoculated with both gastric juice and Streptococcus pneumoniae (81%). Mice inoculated with either Streptococcus pneumoniae or gastric juice showed a separate mortality rate of up to 10% during 18 days after inoculation. XO activity in the lung tissue of the mice inoculated with both gastric juice and bacteria was higher than in mice inoculated with either of them separately. The high mortality rate in the group inoculated with both two agents was reduced to 25% by the administration of pyran-SOD. XO activity raised by Streptococcus pneumoniae and gastric juice was significantly reduced by pyran-SOD. Thus, we suggest an important role in the combined effects of gastric juice and bacteria on pneumonia.

The traditional Chinese medicine banxia houpo tang improves swallowing reflex

A marked depression of swallowing reflex has been found in patients with aspiration pneumonia. We have examined the effects of Banxia Houpo Tang (BHT, Hange Koboku-To in Japanese), on swallowing reflex among the elderly. Thirty-two patients, mean age 74.2 +/- 1.7 years who had at least one episode of aspiration pneumonia, were divided into two groups. Twenty patients took BHT extracts of 7.5 g per day for four weeks, and the other 12 patients took a placebo. The swallowing reflex was measured by a bolus injection of 1 ml of distilled water into the pharynx through a nasal catheter. The reflex was evaluated by the latency time of response, which was the time from the injection to the onset of swallowing. The latency of response decreased significantly from 11.6 +/- 3.0 sec to 2.6 +/- 0.4 sec in the group treated with BHT (p < 0.01), while in the other group with placebo it was from 11.0 +/- 4.0 to 10.8 +/- 3.6 (p > 0.5). Depletion of substance P in the pharynx causes impairments of the swallowing reflex. Substance P in the saliva of treated patients increased from 9.2 +/- 2.5 fmol/ml to 15.0 +/- 2.2 fmol/ml after BHT treatment (p < 0.01), while levels were 8.0 +/- 4.0 fmol/ml before and 7.1 +/- 3.1 fmol/ml after among the placebo group (no significant difference). We suggest that BHT improves the impaired swallowing reflex and may help to prevent aspiration pneumonia in the elderly.

[Community-acquired pneumonia referred for hospital management. Its epidemiology and the diagnostic and therapeutic approaches]

OBJECTIVES

To determine the epidemiology of community-acquired pneumonia referred to the hospital and to characterize the diagnostic and therapeutic approach adopted by physicians.

METHOD

Retrospective epidemiological and descriptive clinical study based on case histories consistent with a diagnosis of community-acquired pneumonia (Fang et al. Medicine, 1990; 69:307-16) of patients referred to hospitals in Soria (Spain) over a period of one year. The patients were grouped by severity and the presence of risk factors for unusual etiology. Initial approaches were compared to those advocated by various sources.

RESULTS

Three hundred eight cases of community-acquired pneumonia were diagnosed, and 82% of the patients were admitted. Mean age was 68 +/- 26 years (43% over 80 years of age). Men accounted for 56%. Two hundred seventeen patients (70%) were classified as seriously ill, 203 (66%) had risk factors for unusual etiology, and 166 (54%) were classified in both categories. Mortality among admitted patients was 13%. Etiological diagnoses did not correspond to the guidelines of the Spanish Society of Pneumology and Chest Surgery (SEPAR), with microbial identification achieved in 5%. Empirical treatment followed SEPAR guidelines in 45% of the cases. The Mensa guidelines were followed in 23% and the Sanford guidelines in 20%.

CONCLUSIONS

The incidence of community-acquired pneumonia in this population is 3.2 cases per 1,000 inhabitants/year. The population is mainly elderly and comorbidity is common, although mortality is low. We believe common criteria should be adopted for managing community-acquired pneumonia and that empirical treatment should be directed toward germs identified in each setting, based on appropriate etiological investigation.

Investigation of effects of anesthesia and age on aspiration in mice through LacZ gene transfer by recombinant E1-deleted adenovirus vectors

To examine the role of disturbed upper airway reflexes in aspiration, we administered 20 microliters of the adenovirus (Ad) vector Ad-CMV-LacZ or 20 microliters of phosphate buffered saline (PBS) intranasally to C57 black mice. We investigated expression of the LacZ gene by this Ad vector in the nostrils of each mouse, with or without anesthesia. Under anesthesia, LacZ gene expression was detected in the lungs of every mouse given the Ad vector. However, no LacZ gene expression was found in the trachea or lungs of mice given the Ad vector without anesthesia. In mice given PBS or wild-type adenovirus transnasally during anesthesia, there was no LacZ gene expression in the nostrils, trachea, or lungs, suggesting that with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal) staining, blue-stained cells indicated transferred LacZ gene expression. These results suggested that aspiration of intranasal solution into lower airways was caused by disturbed upper airway reflexes during anesthesia. This process can be analyzed by the distribution of LacZ gene expression in airways. We next examined the effect of age on anesthesia-induced aspiration. Twenty-six-mo-old mice exhibited more LacZ gene expression in their lungs than did 6-mo-old mice at a concentration of 0.5 to 4.0% halothane in 100% oxygen. This suggests that light anesthesia may depress upper airway reflexes and cause aspiration in older animals. This novel model of aspiration, generated with the Ad-CMV-LacZ vector, may be useful for elucidating the mechanism of development of aspiration pneumonia in relation to age-related impairment of upper airway reflexes.

Mechanisms and prevention of pneumonia in the elderly

Pneumonia is not only a major cause of death for elderly persons, but also imposes substantial personal morbidity and burdens on the health care system. An understanding of the pathogenesis of this serious illness could allow us to devise methods for curbing the incidence and severity of the disease. Pathophysiological issues and preventative measures are the subject of this review.

Aspiration-Induced Pulmonary Injury

Pulmonary aspiration of gastric contents can cause a spectrum of sequelae that spans from relatively minor to rapidly lethal disease. To emphasize the extent of this spectrum and to encompass both noninfectious complications and infection, we use the term “aspiration-induced pulmonary injury” rather than “aspiration pneumonia.” In this article we review the relevant literature, focusing on more recent insights into the pathogenesis of lung injury, the natural history of aspiration, risk factors, the relationship between aspiration and infection, and recommendations for management. The relevance to human disease of studies using intra-airway acid instillation in animals is questioned. We discuss the difficulties in predicting the clinical course after aspiration. We identify risk factors for aspiration-induced pulmonary injury that are commonly encountered in the intensive care unit, and discuss in detail factors of special interest to the intensivist, including the impact of tracheal intubation; the effects of enteric intubation, particularly the comparison between pre- and postpyloric routes of enteric feeding administration; and the relative risks associated with particular feeding protocols. We conclude with recommendations regarding treatment and prevention strategies.

Oral health and history of respiratory tract infection in frail institutionalised elders

OBJECTIVES

The purpose of this study was to look for a relationship between history of respiratory tract infection (RTI) and oral health in very old subjects.

SETTING AND SUBJECTS

302 frail elders (mean age: 85 years) living in a medical care facility were examined by one dentist.

OUTCOME MEASURES

The incidence of RTI over 1 year had been recorded along with markers of nutritional status and degree of dependency. The oral examination comprised an evaluation of hygiene, quality of prostheses and the prevalence of caries, periodontal disease and mucosal disorders.

RESULTS

One third (33%) of the subjects had experienced at least one episode of RTI, and a fifth (19%) had visited the dentist in emergency. The incidence of RTI had been greater among dentate subjects and those who came to the dentist in emergency. The dentate subjects with a history of RTI had higher plaque score (P = 0.02). Half (49%) of the subjects had oral disorders that could develop in a dental emergency and these subjects had had a higher risk of RTI (relative risk: 1.9, 95% confidence interval: 1.1-3.9). The presence of selected oral disorders associated with low serum albumin increased the relative risk of having had RTI to 3.2 (1.5-6.7). The association between presence of actual oral health problems and previous experience of RTI was more noticeable in those who had poor general health or were more debilitated.

CONCLUSIONS

The present study suggests that poor oral hygiene and the presence of potential emergency could be major risk factors for RTI among the frail elderly.

Quantitative aspiration during sleep in normal subjects

STUDY OBJECTIVE

To determine the within-subject variability and to estimate the quantity of occult aspiration of nasopharyngeal secretions during sleep in normal humans.

DESIGN

Prospective duplicate full-night sleep studies.

SETTING

Pulmonary sleep laboratory, university hospital.

PARTICIPANTS

Ten normal male volunteers aged 22 to 55 years.

INTERVENTIONS

Two full-night polysomnographic recordings with infusion of 2 mL/h radioactive 99mTc tracer into the nasopharynx through a small catheter during EEG-documented sleep. Standard lung scans were conducted immediately following final awakening. Aspiration was defined as the presence of radioactivity in the pulmonary parenchyma on two separate views.

RESULTS

A mean sleep efficiency of 85.7 +/- 2.6% was found with no difference between the two study nights. A total of 5 of the 10 subjects studied had tracer evident in the pulmonary parenchyma following final awakening. Three had the tracer apparent following the first-night study and four had tracer apparent following the second-night study. Thus, two subjects aspirated on both nights. Comparing the subjects who aspirated with those who did not, no significant difference could be found for age, time spent in bed, sleep efficiency, apnea-hypopnea index, arousal plus awakening index, or percent of sleep time spent in a supine position. The quantities of tracer aspirated were on the order of magnitude of 0.01 to 0.2 mL.

CONCLUSIONS

Aspiration measured by this technique occurs commonly in healthy young men during sleep, is unrelated to sleep quality, and is variable within subjects studied on more than one occasion. The quantity aspirated is of an order of magnitude likely to contain bacterial organisms in physiologically significant quantities.

Pulmonary aspiration in hospitalized adults

Until recent years, pulmonary aspiration attracted remarkably little clinical investigation. Although aspiration was considered a common occurrence in hospitalized individuals, with serious and even fatal consequences, clinicians had limited scientific data to guide practice. Consequently, approaches to this problem were based largely on unsystematic observations, intuition, and tradition. Recent investigations on the subjects of aspiration have increased our understanding of patients at risk for aspiration, the value of diagnostic methods, and the efficacy of interventions to prevent or limit aspirations. Results of these studies call to question many time-honored adages and practices. Considerable uncertainty remains and more investigation is necessary before management decisions can be characterized clearly and clinical strategies defined. This review focuses on pulmonary aspiration and enteral feeding in the critically ill adult. Factors implicated in aspiration in this population are highlighted and evidence to support the application of interventions prescribed commonly is presented.

The regulation of pulmonary immunity

No evidence has emerged which suggests that the principles of immunity derived from studies on cells from other body sites are contradicted in the lung and its associated lymphoid tissue. What is clear, however, is that the environment dictates the types of cells, their relationship to one another, and what perturbing events will set in motion either the development of an "active" immune response or tolerance. Investigating mechanisms for the development of lung immunity has increased our understanding of how human diseases develop and is continuing to suggest new ways to manipulate pulmonary immune responses. Demonstration that lung cells regulate both nonspecific inflammation and immunity through the expression of adhesion molecules and the secretion of cytokines offers hope for ways to design more effective vaccines, enhance microbial clearance in immunosuppressed hosts, and to suppress manifestations of immunologically mediated lung disease. Important lung diseases targeted for intensive research efforts in the immediate future are tuberculosis, asthma, and fibrotic lung disease. Perhaps even the common cold might be conquered. Considering the pace of current research on lung immunity, it may not be too ambitious to predict that these diseases may be conquered in the next decade.