Feature Article
|
Management of Community-Acquired Pneumonia in the Elderly (Part Two of a two-part series. Part One
appeared in the July 2003 issue of the journal.)
From the Department of Medicine, University of Wisconsin Hospital and Clinics. Dr. Reichmuth is chief medical resident, and Dr. Meyer is associate professor of Medicine and medical director of Lung Transplantation.
Lower respiratory tract infection is a leading cause of morbidity and mortality in older adults. Minimizing risk factors and optimizing therapy can have a significant impact on the incidence and severity of pneumonia in the elderly. Physicians should identify risk factors, immunize against pneumococcus and viral influenza, and adequately treat chronic medical conditions to decrease the likelihood of developing pneumonia. Rapid treatment of the elderly patient with an adequate antimicrobial regimen modified for a given patient’s age and comorbid conditions can improve outcome. (Annals of Long-Term Care: Clinical Care and Aging 2003;11[10]:19-22).
Introduction
Pneumonia and influenza together are the seventh leading cause of death in the United States and the fifth leading cause of death in individuals older than age 65. The diagnosis and management of lower respiratory tract infection (RTI) requires modifications to approaches typically taken for younger populations. Not only is the incidence of pneumonia higher in those over age 65, but morbidity and mortality are increased and accompanied by a greater likelihood of hospitalization, a longer length of stay in the hospital, and a prolonged recovery period for many individuals despite successful therapy.
Part One of this article examined functional and structural alterations in the aging lung, risk factors for pneumonia, pathogens that account for infection, and diagnosis.
Treatment of Community-acquired pneumonia
Treatment considerations for community-acquired pneumonia (CAP) in the elderly are similar to those in younger patients. Antibiotics that cover S. pneumoniae, H. influenza, and gram-negative rods should be used (Table).1,3,4 Although atypical organisms are less common, Legionella must be considered, especially in the summer months and in patients with COPD. Because of the high rates of drug-resistant S. pneumoniae (DRSP), choosing an agent that will be effective against this pathogen is extremely important. Risk factors for DRSP include age older than 65, treatment with a b-lactam antibiotic within the last 3 months, alcoholism, multiple medical comorbidities, immunosuppression, or exposure to a child day care environment. Oral antipneumococcal fluoroquinolones are an excellent choice for outpatient treatment due to their once-daily dosing, excellent bioavailability, good lung tissue concentrations, and low incidence of drug–drug interactions. The newer fluoroquinolones cover all of the organisms mentioned previously in addition to atypical agents. However, there is concern for emerging fluoroquinolone-resistant S. pneumoniae; levofloxacin failures have been reported, and excessive use of fluoroquinolones will likely result in progressively resistant pneumococci.2�Alter natives include macrolides/azalides such as clarithromycin and azithromycin (but not erythromycin due to high prevalence of resistant H. influenza). These newer macrolide/azalide agents are a reasonable alternative for patients with low risk for pneumonia due to DRSP and/or gram-negative rods, but they should not be used alone for seriously ill patients. If the risk of DRSP is low, treatment with cefuroxime, cefpodoxime, or amoxicillin could be considered.3 If the risk of pneumonia caused by DRSP is high or the patient has increased risk for gram-negative infection, use of a third-generation cephalosporin with a macrolide could be considered.
When the decision is made to admit a patient to the hospital, parenteral antibiotics should be administered under most circumstances, with conversion to oral therapy once the patient is clinically stable. The American Thoracic Society (ATS) recommends a switch from intravenous to oral administration once the following four criteria are met: improved cough and dyspnea, afebrile on two occasions 8 hours apart, decreasing white blood cell count, and adequate oral intake.3 Regimens should once again cover the most likely pathogens. Intravenous third-generation lactams plus a macrolide (other than erythromycin) or antipneumococcal fluoroquinolones are reasonable choices for patients at low risk for Pseudomonas or methicillin-resistant S. aureus (MRSA). In a Medicare-sponsored study with approximately 13,000 patients, these two regimens were found to be associated with reduced mortality compared with other regimens.4
If concern exists for pneumonia caused by P. aeruginosa (bronchiectasis, severe COPD, malnutrition, steroid use greater than 10 mg/day for more than one month, broad spectrum antibiotics for more than 7 days in the past 30 days), two antipseudomonal agents should be simultaneously administered.5 Aminoglycosides should be avoided, however, due to the increased risk of ototoxicity and nephrotoxicity in elderly patients.6,7 If MRSA is a likely pathogen, vancomycin should be administered.
Receiving antibiotics within 8 hours of hospital arrival has been shown to reduce 30-day mortality and reinforces the need for rapid assessment and initiation of appropriate antibiotic therapy.8 For most patients, 7-10 days of therapy will be adequate, but longer duration of therapy (10-14 days) may be required for those with infection caused by Legionella, M. pneumoniae, or C. pneumoniae.3 Up to 72 hours of treatment may be required before clinical improvement occurs.
Treatment of influenza, if started within 24-48 hours of the onset of symptoms, has been shown to reduce the duration of symptoms as well as viral shedding by 1-2 days and to reduce the severity of the illness.9,10 Options for pharmacologic treatment include the older agents amantadine or ramantadine, which are active against influenza A (causes the majority of the influenza outbreaks), or the newer neuraminidase inhibitors that are approved for both influenza A and B. The older agents are cheaper but can be effective. There have been no good comparison studies between these agents and the neuraminidase inhibitors. Amantadine appears to have a higher incidence of central nervous system side effects in the elderly, making ramantadine the better choice.11 Resistance develops more readily with amantadine and ramantadine than with the neuraminidase inhibitors.11 Zanamivir, delivered via inhalation, and oseltamivir, taken orally, are the only available FDA-approved neuraminidase inhibitors. They appear to be equally efficacious, but airway reactivity is a concern with zanamivir, and drug delivery with the inhaled agent may be suboptimal in the elderly patient. Diggory et al12 found that 24 of 37 elderly patients were unable to administer the inhaled drug 24 hours after being taught how to use the delivery device.
Prevention
Vaccinations of the elderly against both pneumococcus and influenza are efficacious and recommended for patients 65 years of age as well as those with certain comorbidities. Few trials have studied the efficacy of the current inactivated influenza vaccine. However, a meta-analysis of 20 cohort studies found that vaccination had an efficacy of 53% for preventing pneumonia, 50% for preventing hospitalization, and 68% for preventing death.13 A Cochrane Review of nine trials found that COPD exacerbations were significantly reduced by influenza vaccination.14 Side effects were low and primarily local; however, the Cochrane Review did find that the elderly were more likely to have these local reactions.
Pneumococcal vaccination is recommended for all patients age 65 years or older. The Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommends a booster after five years in individuals who received their first vaccination when they were younger than age 65.15 Because vaccination has minimal side effects and no good evidence exists that revaccination in patients 65 years of age is contraindicated, the authors revaccinate all patients after five years. Currently there are two 23-valent polysaccharide vaccines approved, and a heptavalent conjugated vaccine is under consideration. The conjugated vaccination has the advantage of potentially providing more immunologic memory. The heptavalent vaccination would cover slightly fewer serotypes than the polysaccharide vaccination (50-80% vs 80-90%).16
While there is strong evidence that the vaccination prevents bacteremic pneumococcal pneumonia in all age groups with an efficacy of 60-80%,17 its efficacy in preventing noninvasive pneumococcal pneumonia in the elderly is less clear. (Note: Many of the studies were not done with the current 23-valent polysaccharide vaccine.) Even those studies that have been done with 23-valent vaccines have not clearly shown a reduction in noninvasive pneumococcal pneumonia in adults. Koivula and associates18 found that the 14-valent vaccine reduced the incidence of pneumococcal pneumonia in elderly persons considered “high risk” for developing pneumonia with an efficacy of about 60%, compared with no reduction in the general population of elderly. Despite the proven cost-effectiveness of vaccinating the elderly, only 25-35% of the U.S. elderly population has received the vaccination.19,20
Chemoprophylaxis for exposure to influenza should be strongly considered, especially in those with increased risk of complications from this illness. Currently, oseltamivir is the only agent approved for chemoprophylaxis, though there are data supporting the other agents. The neuraminidase inhibitors may be the preferred agents due to less emergence of drug resistance and lower incidence of side effects in the elderly. A recent study demonstrated a significant reduction in laboratory-confirmed influenza among family contacts in those treated with zanamivir compared with placebo (4.1% vs 19%).21
In addition to vaccination and influenza chemoprophylaxis, other interventions may prevent lower RTI in the elderly. An optimally functioning immune system is likely of key importance in preventing respiratory infection in the aging individual. Optimal nutrition, caloric restriction (with adequate nutrition maintained), and antioxidants may improve immune responses and bolster resistance to pulmonary infection. Dietary supplementation with vitamins E and/or C has been shown to antagonize or even restore the age-associated decline in immune function that occurs with advancing age.22-24
Conclusion
More than 30 million people in the United States are 65 years of age or older, and great strides can be made in maintaining their health and longevity by aggressively addressing the leading infectious causes of death in this group: pneumonia and influenza. Prevention should be at the forefront of efforts to limit the morbidity and mortality associated with pneumonia in the elderly, accompanied by the hope that biotechnology will continue to provide more effective preventive options and therapeutic interventions. Elderly patients are more likely to have atypical clinical presentations, which may hinder efforts to rapidly diagnose and treat the illness before it progresses to severe illness. Recognition of the presence of pneumonia, accurately assessing the severity of the infection, and rapid administration of empiric therapy that adequately covers potential pathogens are key to the successful treatment of the elderly patient with CAP. G
References
1. Bartlett JG, Dowell SF, Mandell LA, et al. Practice guidelines for the management of community-acquired pneumonia in adults. Infectious Diseases Society of America. Clin Infect Dis 2000;31(2):347-382.
2. Chen DK, McGeer A, de Azavedo JC, Low DE. Decreased susceptibility of Streptococcus pneumoniae to fluoroquinolones in Canada. Canadian Bacterial Surveillance Network. N Engl J Med 1999;341(4):233-239.
3. Niederman MS, Mandell LA, Anzueto A, et al. Guidelines for the management of adults with community-acquired pneumonia. Diagnosis, assessment of severity, antimicrobial therapy, and prevention. Am J Respir Crit Care Med 2001;163(7):1730-1754.
4. Gleason PP, Meehan TP, Fine JM, et al. Association between initial antimicrobial therapy and medical outcomes for hospitalized elderly patients with pneumonia. Arch Intern Med 1999;159(21):2562-2572.
5. El-Solh AA, Sikka P, Ramadan F, Davies J. Etiology of severe pneumonia in the very elderly. Am J Respir Crit Care Med 2001;163(3 Pt 1):645-651.
6. Cronin RE. Aminoglycoside nephrotoxicity: pathogenesis and prevention. Clin Nephrol 1979;11(5):251-256.
7. Moore RD, Smith CR, Lipsky JJ, et al. Risk factors for nephrotoxicity in patients treated with aminoglycosides. Ann Intern Med 1984;100(3):352-357.
8. Meehan TP, Fine MJ, Krumholz HM. Quality of care, process, and outcomes in elderly patients with pneumonia. JAMA 1997;278(23):2080-2084.
9. Treanor JJ, Hayden FG, Vrooman PS, et al. Efficacy and safety of the oral neuraminidase inhibitor oseltamivir in treating acute influenza: A randomized controlled trial. US Oral Neuraminidase Study Group. JAMA 2000;283(8):1016-1024.
10. Wingfield WL, Pollack D, Grunert RR. Therapeutic efficacy of amantadine HCl and ramantadine HCl in naturally occurring influenza A2 respiratory illness in man. N Engl J Med 1969:281(11):579-584.
11. Hayden FG. Antivirals for pandemic influenza. J Infect Dis 1997;176(Suppl 1): S56-S61.
12. Diggory P, Fernandez C, Humphrey A, et al. Comparison of elderly people’s technique in using two dry powder inhalers to deliver zanamivir: A randomised controlled trial. BMJ 2001:322(7286);577-579.
13. Gross PA, Hermogenes AW, Sacks HS, et al. The efficacy of influenza vaccine in elderly persons: A meta-analysis and review of the literature. Ann Intern Med 1995;123(7):518-527.
14. Poole PJ, Chacko E, Wood-Baker RW, Cates CJ. Influenza vaccine for patients with chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2000;(4):CD002733.
15. Prevention of pneumococcal disease: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 1997;46(RR8):1-24.
16. Hausdorff WP, Bryant J, Kloek C, et al. The contribution of specific pneumococcal serogroups to different disease manifestations: Implications for conjugate vaccine formulation and use, part II. Clin Infect Dis 2000;30(1):122-140.
17. Ortqvist A. Pneumococcal vaccination: Current and future issues. Eur Respir J 2001;18(1):184-195.
18. Koivula I, Sten M, Leinonen M, Makela PH. Clinical efficacy of pneumococcal vaccine in the elderly: A randomized, single-blind population-based trial. Am J Med 1997;103(4):281-290.
19. Sisk JE, Moskowitz AJ, Whang W, et al. Cost-effectiveness of vaccination against pneumococcal bacteremia among elderly people. JAMA 1997;278(16):1333-1339.
20. Centers for Disease Control and Prevention. Pneumococcal and influenza vaccination levels among adults aged = 65 years. Unitied States 1995. MMWR 1997;46(39):913-919.
21. Hayden FG, Gubareva LV, Monto AS, et al. Inhaled zanamivir for the prevention of influenza in families. Zanamivir Family Study Group. N Engl J Med 2000;343(18):1282-1289.
22. de la Fuente M, Ferrandez M, Burgos MS, et al. Immune function in aged women is improved by ingestion of vitamins C and E. Can J Physiol Pharmacol 1998;76(4):373-380.
23. Enioutina EY, Visic VD, Daynes RA. Enhancement of common mucosal immunity in aged mice following their supplementation with various antioxidants. Vaccine 2000;18(22):2381-2393.
24. Moriguchi S, Moruga M. Vitamin E and immunity. Vitamins and Hormones 2000;59:305-336. Annals of Long-Term Care - ISSN: 1524-7929 - Volume 11 - Issue 10 - October 2003 |