Diagnosis and Treatment of Common Infections in Nursing Home Residents
Author: Thomas T. Yoshikawa, MD, Chairman, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, and Martin Luther King, Jr.-Charles R. Drew Medical Center, Los Angeles, Calif.
A nursing home resident was celebrating her 100th birthday. When asked what was the best part of becoming 100, she replied, "There’s no peer pressure."
Editor’s Note—The population aged 65 years and older in the United States is rapidly increasing. The US elderly population (65+ years) will double in number over the next quarter century. With the growing aging population comes an increasing need for long-term care, especially skilled nursing care found in nursing homes. The frail and very old nursing home resident has age-related immunological changes, physical impairments and cognitive disorders, and chronic underlying diseases that compromise host resistance. Consequently, nursing home residents are highly susceptible to infections and their complications. Furthermore, infections are one of the most common reasons for transferring residents from a nursing home to an acute care facility. The diagnosis of infections in the nursing home setting is difficult, not only because of the atypical clinical manifestations of infection in the very old but also for the major differences in the goals of care, staffing availability, access to immediate laboratory tests, diagnostic criteria for infections, and types of primary care providers in a nursing home compared with a hospital setting. Moreover, issues of advance directives and resident/family wishes regarding acute interventions will greatly influence the approach to managing the infection and whether to transfer the resident to another facility. The most common infections identified in nursing home residents include urinary tract infection, respiratory tract infections (pneumonia/bronchitis), and skin and soft tissue infections (infected pressure ulcer). Less common infections (not discussed in this review) are tuberculosis, viral infections, gastroenteritis, hepatitis, conjunctivitis, infective endocarditis, and scabies. The approach to diagnosis and treatment of pneumonia, urinary tract infection, and infected pressure ulcer in nursing home residents will be summarized in this report.
Demographics of Aging
America is aging. The current US elderly population (persons 65 years and older) is approximately 13% (or 35 million Americans) in contrast to only 4% in 1900.1 It is projected that the number of elderly persons in 25-30 years will double (70-75 million) and constitute 21% of the entire US population.1 Moreover, the percentage of the population aged 80 years and older will be growing disproportionately at a greater rate than those aged 65-79 over the next quarter century. This subgroup of the elderly is the most frail and vulnerable to a variety of diseases and disorders, especially infections.
With increasing age comes a greater risk and need for long-term care. The lifetime risk for using a nursing home for an average person is approximately 45-50%.2 Presently there are approximately 1.5 million persons residing in nursing homes; it is projected this number will reach 5 million by year 2030.2-4 The typical nursing home resident is usually female, aged 80 years or older, disabled, and often cognitively impaired. The average length of stay is beyond 6 months and often longer than 1 year. Nursing home residents require skilled nursing care and a physician of record, although there are other types of long-term care facilities that provide less intensity of medical/nursing services depending on the individual’s needs (eg, assisted living, residential care). Whether the health risks to the elderly, especially for infections, in other types of long-term care facilities are similar to nursing home residents is unclear.
Aging and Susceptibility to Infections
The increased susceptibility of nursing home residents to infection is most likely due to several factors related to the host and environment. The normal process of aging is associated with immune dysregulation, but it is unclear how much these immune changes contribute to the vulnerability to infection.5 The identifiable defects in age-associated immune dysregulation are cell-mediated immunity and humoral immune function, the latter being affected by aging to a lesser degree. Thus, resistance to infections such as tuberculosis and herpes zoster, which are controlled by cell-mediated immunity, can be diminished with increasing age. Similarly, antibody responses (humoral immunity) may be blunted in older persons immunized with influenza or pneumococcal polysaccharide vaccines.6 In addition, nutritional factors can have an effect on immune function and susceptibility to infection in the elderly.7 Nursing home residents may be suffering from malnutrition (deficiency of protein and calories) in 15-66% of cases.8 Certainly, coexisting chronic diseases, particularly those that may alter host resistance mechanisms, may also increase the risk to infection.6 Thus, from the host perspective, it is probably the combined effect of age-associated immune dysfunction and chronic underlying diseases that places the frail nursing home resident at such jeopardy to infectious diseases.
The nursing home setting may also place the frail elderly resident at risk to infection. A closed environment, such as a nursing home, favors regular exposure to potential pathogens because of frequent interactions and contacts with other residents and staff; limited ventilation, filtration and removal of recirculated air that might contain pathogens; and free movement of other residents who may be harboring an infection.9 Moreover, many nursing homes lack an adequate infection control program because of insufficient resources to have an onsite health professional trained in infection control, as well as the capacity to implement such a program. Thus, there may be inadequate surveillance of infections, which would then limit the ability to detect early outbreaks and institute preventive measures.
Clinical Manifestations of Infection
The hallmark of infection is the presence of fever. Fever in children may often be caused by relatively benign or nonlife-threatening infections such as upper respiratory tract infections and viral diseases. In contrast, the older adult with an elevated body temperature is invariably a result of an underlying serious infection, usually caused by bacteria and infrequently by viral illnesses.10 Thus, when confronted with an elderly nursing home resident with a fever, assume a serious infection is present until proved otherwise.
Unfortunately, many elderly persons who harbor a serious or even life-threatening infectious disease may not elicit a febrile response. Numerous studies have shown that up to one-third of elderly patients with pneumonia, infective endocarditis, meningitis, intraabdominal infections, and a variety of nosocomial infections may demonstrate blunted fever or normal to low body temperatures.11,12 Rather, presenting features of an infection could be altered mental status (eg, delirium), falls, urinary incontinence, anorexia, weakness, lethargy, focal neurological signs, or unexplained change in functional status (eg, decline in activities of daily living: eating, dressing, bathing, ambulation, toileting, transferring, or instrumental activities of daily living: driving, gardening, shopping, banking, telephone use, cleaning).12
To add further complexity to the diagnostic use of fever as a marker for infection, studies have also shown that frail elderly nursing home residents may have lower than normal baseline body temperatures. In some cases, despite a low basal body temperature, a nursing home resident who contracts an infection may muster a rise in body temperature. However, this elevation in body temperature may not reach a criterion for fever (eg, 100°F), and consequently an infectious disease is overlooked or misdiagnosed.13 Studies have demonstrated that a rise in baseline body temperature of at least 2°F in frail elderly nursing home residents has a high correlation with the presence of an underlying infectious disease process.13,14 Moreover, when using a lower threshold for defining a fever response, the sensitivity of diagnosing an infection improves with some loss of specificity. Table 1 summarizes newer diagnostic criteria for fever in frail nursing home residents.13-15
Nursing Home vs. Hospital
Long-term care facilities such as nursing homes are substantially different from acute-care facilities (hospitals) in terms of goals of care, environment, types of patients, available onsite health providers, capacity to diagnose and treat diseases such as infections, and the ability to implement infection control measures. Table 2 summarizes many of the contrasting features between a nursing home and a hospital.16,17
Clearly, a nursing home houses primarily very old and frail individuals who suffer multiple underlying disorders or disabilities and have either physical or mental (or both) functional incapacities. The average nursing home resident will reside at the facility for 1 year or longer. The environment is more conducive to a homelike atmosphere with the goals of care predominantly of long-term maintenance care. Nurses and nursing assistants provide the bulk of bedside care with physicians visiting the residents on average of once every 30-60 days.17 Awareness and preliminary assessment of an acute problem is dependent largely on the evaluation by the onsite nursing staff. The nursing staff then contacts the resident’s physician by phone or facsimile (fax) and communicates the findings. Based on the nursing staff’s findings and the clinician’s clinical judgment, a course of action will be initiated. Onsite laboratory testing or radiological capabilities are not available in most nursing homes. Thus, immediate diagnostic tests in nursing homes are virtually nonexistent. Finally, pharmacological interventions are usually limited to oral medications and intramuscular injections. Thus, the diagnostic and therapeutic approach to managing infections in nursing home residents must be different, is often complex, and lacks consensus among clinicians because of insufficient clinical studies in this setting.
The decision to transfer a nursing home resident to an acute-care facility can be facilitated by having discussions with the nursing home resident and family/caregiver upon admission to the long-term care facility and implementing an advanced directive. Without an advanced directive, the physician should base the decision regarding transfer on available institutional policies; clinical condition, underlying diseases, and prognosis of the resident; efficacy and cost effectiveness of the proposed interventions in the hospital; the capacity of the nursing home to provide necessary care and support to the resident; and wishes of the resident or family/caregiver.18
Important Infections in Nursing Home Settings
Several studies have shown that the most frequently identified infections in nursing home residents using positive blood cultures as the confirmatory test are pneumonia, urinary tract infection, and skin/soft tissue infection (infected pressure ulcer), which can easily be remembered by the acronym, "PUS."19-21 These 3 infections consistently account for approximately 75% of the infections isolated and documented in nursing home residents.19-21 Thus, the focus of this review will be on these 3 infections. However, it should be noted that other infections such as viral infections (influenza, respiratory syncytial virus, rhinovirus, herpes zoster), conjunctivitis, hepatitis, gastroenteritis, infective endocarditis, scabies, and tuberculosis do occur relatively frequently in nursing home residents and should not be overlooked in the evaluation of fever or a suspected infection in this setting.22-28
Diagnostic Approach to Suspected Infection in Nursing Home Residents
Diagnosing infection and initiating appropriate treatment in a nursing home resident is one of our most difficult challenges in geriatric medicine. As discussed earlier, the atypical clinical features of infections in this population, the inability of many residents to be able to communicate or cooperate, the difficulty of the resident’s physician to be at the facility for evaluation, limited nursing staff, and lack of quick access to diagnostic tests (laboratory and radiology) require a different paradigm in the approach to managing infections in the nursing home setting. Moreover, the level of diagnostic and therapeutic intervention may be mitigated by an advance directive or wishes of the resident and/or family/caregiver.
Immediate Transfer to an Acute-Care Facility. Vital signs should be taken by the nursing staff on residents who manifest acute onset of delirium, altered consciousness, chills, change in functional status (eg, self-care or ambulatory to bedridden state), respiratory distress, vomiting, diarrhea, or unexplained agitation. The nurse should obtain a pulse oximetry (most nursing homes have pulse oximeters). The nurse must communicate to the physician immediately by phone or fax any significant changes in vital signs in association with any of the above symptoms/signs, or presence of an abnormal oxygen saturation (below 95%).29 The physician should determine any advance directives and prior wishes of the resident or family/caregiver before making a decision on management. In the absence of prohibition of acute intervention, residents with the above findings should be immediately transferred to an acute-care hospital. If acute transfer to a hospital is not an option for the physician, then evaluation and treatment will be dictated by initial findings, available resources in the nursing home, and limits of intervention as imposed by the resident and/or family/caregiver.
Initial Evaluation of a Resident with Fever or Suspected Infection. Nursing staff in a nursing home should obtain vital signs in any resident who exhibits any symptoms or signs of an infection (eg, cough, sputum production, increase urination, dysuria, diarrhea), unexplained change in functional status, anorexia, new-onset urinary incontinence, acute confusion, or falls. The presence of 1 temperature reading of > 100°F (any route), 2 or more readings of > 99°F orally or > 99.5°F rectally, or an increase of basal temperature by 2°F or more (eg, tympanic membrane temperature) should be interpreted as indicating fever with its most likely cause being an infection.
The onsite nurse performs the initial evaluation for possible sites of infection by examining for respiratory changes, cough, course rales, urinary incontinence, skin changes, presence of diarrhea, etc. These findings are conveyed directly to the resident’s physician. Make an assessment of the findings and order preliminary tests for further evaluation of a specific infection or determine whether hospitalization is justified (see earlier discussions on transferring a resident to a hospital).
Focus the initial onsite evaluation on pneumonia, urinary tract infection, and/or skin/soft tissue infections. Keep in mind that more than one infection can be present in these residents. Regardless of the specific infection being considered, obtain a complete blood count on all residents with suspected infection. The presence of an elevated white blood cell count (³ 14,000 cells/mm3) or a left shift (> 6% band neutrophils or metamyelocytes or total band neutrophil count ³ 1500 cells/mm3) warrants careful evaluation for the presence of infection even in the absence of fever.18 Without specific symptoms and signs for a focal infection and in the absence of fever, leukocytosis, and/or left shift, the likelihood of a bacterial infection is low and further diagnostic tests for such an infection may not be justified because of low yield.30 However, nonbacterial infections cannot be excluded. There are little data indicating the usefulness and benefits of obtaining blood cultures in the nursing home in residents suspected of having an infection.18 If the clinical condition warrants blood cultures, the nursing home resident most likely should be transferred to an acute hospital.
Pneumonia
Diagnostic Steps. The primary differential diagnosis of pneumonia in the nursing home setting will be acute bronchitis. Although the definitions of common infections in a long-term care setting were established more than 10 years ago, they are routinely used today.31 The definitions for bronchitis and pneumonia are summarized in Table 3.31 The diagnosis of pneumonia will require presence of clinical symptoms/signs plus an abnormality on chest radiograph consistent with a pneumonic process.18,31 However, in residents who are clinically septic and/or are having respiratory distress, immediate vital signs and pulse oximetry should be obtained before a chest radiograph is ordered. If the nursing staff indicates abnormalities of vital signs and/or abnormal oxygen saturation values, examine the patient as soon as possible or, if going to the facility is not possible, transfer the resident to an acute hospital.29
In residents who are clinically stable but are suspected to have pneumonia, implement the following sequence of diagnostic steps after obtaining vital signs:18
1. Obtain a pulse oximetry in residents with respiratory rate of > 25 breaths/min. This will document hypoxemia and have some predictive value on short-term mortality and impending respiratory failure, ie, the greater the hypoxemia, the greater the risk for respiratory failure and possible death. Oxygen saturation of less than 95% is mildly abnormal and less than 90% indicates significant hypoxemia.
2. Order a chest radiograph if hypoxemia is documented or suspected to confirm the presence of a new infiltrate consistent with pneumonia and associated complications (effusion, abscess) or to exclude other morbid conditions (heart failure).
3. Obtain respiratory secretions (expectorated sputum or nasopharyngeal aspiration) to assess for purulence. Send sputum for Gram stain with cytological screening for squamous epithelial cells, as well as culture and sensitivity tests. This can only be done if resources are available for transportation of the specimen within 1-2 h of collection.
4. Instruct the laboratory to set up the specimen for culture and sensitivity only if the specimen is acceptable (ie, smear shows < 25 squamous cells per low power field on light microscopy examination).
Please note that steps 3 and 4 might not be possible all the time. Getting respiratory secretions, even in acute care facilities, from elderly patients are problematic, and timely transportation of secretions with appropriate instructions to clinical laboratories from patients in nursing homes could be very difficult.
Treatment Site. Once the diagnosis of pneumonia is confirmed, the next decision is whether to treat the resident in the nursing home or transfer the individual to a hospital. Several studies indicate that nursing home residents who are clinically stable with mild-to-moderately severe pneumonia can be effectively treated in the nursing home with outcomes similar (or even better!) to those treated in the acute hospital.32-34 Thus, it is preferable to treat most pneumonias in the nursing home provided the following conditions exist: 1) Pneumonia is mild-to-moderate in severity; 2) there are no complications of pneumonia such as abscess or effusions; 3) resident’s overall clinical condition and underlying diseases are stable (eg, congestive heart failure, diabetes mellitus); 4) there are adequate nursing staff and equipment to monitor the resident regularly; 5) a physician (as well as a nurse practitioner or physician assistant) is able to examine the resident daily; 6) the resident is able to take oral medication or receive intramuscular injections; and 7) routine laboratory (complete blood count, renal function, and electrolytes) and radiological tests (chest radiograph) can easily be obtained.
Etiology and Treatment. The microbial causes of pneumonia in nursing home residents have not been investigated extensively because of the difficulty in performing invasive diagnostic studies in this frail population. Nevertheless, the available data indicate that Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and aerobic gram-negative bacilli are the most commonly isolated pathogens.32,35 The role of aerobic Gram-negative bacilli such as Klebsiella spp in nursing home-acquired pneumonia has been somewhat controversial with some studies showing a low isolation rate.36-38
Moreover, the role of anaerobic bacteria in pneumonia in nursing home residents has not been clearly defined, despite aspiration (and thus aspiration pneumonia) being a major mechanism for causing lower respiratory tract infections.39,40 Furthermore, whether atypical pathogens, ie, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella spp are causative agents in nursing home-acquired pneumonia is controversial. Many treatment guidelines for pneumonia in nursing home residents provide coverage for atypical pathogens with suggestive evidence of improved mortality.41,42
Antimicrobial regimens for treating nursing home-acquired pneumonia are primarily the quinolones, second- or third-generation cephalosporins or beta-lactam/beta-lactamase inhibitors.32,34,41,42 For treatment in the hospital, initiate intravenous antibiotics followed by oral drugs when appropriate clinical parameters are met.32,43 If the patient is able to tolerate oral antibiotics and remains stable, the patient may be transferred back to the nursing home for completion of treatment. If therapy is initiated in the nursing home, prescribe either intramuscular or oral agents. Intramuscular route is chosen when the resident is unable to take oral medications. Table 4 summarizes suggested antibiotic regimens for treatment in the hospital or nursing home, as well as duration of therapy.
Maintain adequate nutrition and hydration during treatment of this infection (or any infection). Dehydration and undernutrition are common findings in nursing home residents.7,32 In addition, monitor for adequate oxygenation by pulse oximetry and observe for complicating factors such as heart failure, pulmonary emboli, pressure ulcers, and side effects of the antibiotics. Determine the level of change in functional capacity during the pneumonia episode (eg, activities of daily living, mental status) and monitor for improvement of these parameters as the pneumonia improves. Failure of a parallel (although often delayed) improvement of functional status with pneumonia should alert the clinician for possible complications associated with the lung infection or coexistence or development of a new clinical problem.
Following recovery from the pneumonia, the resident should be administered pneumococcal vaccine, if this has not already been done. Influenza immunization should be provided during the early winter months (October-December) on an annual basis.
Urinary Tract Infection
Prevalence and Clinical Challenges. Urinary tract infection (UTI) is the most common infection identified in residents of nursing homes.44 UTI in this review is defined as the presence of a significant number of bacteria in the urine resulting in a host response, which may be genitourinary complaints, systemic or constitutional symptoms, and/or changes in functional status. Although the vast majority of bacteriuria in elderly persons is asymptomatic, it is one of the most common (and inappropriate) reasons for initiating antimicrobial therapy in long-term care facilities.45 Conversely, UTI is a frequent source of bacteremia in nursing home residents and a common justification for transfer to an acute hospital.45 Moreover, nursing home residents may have a chronic indwelling bladder catheter, which adds to the risk of potential UTI and urosepsis. However, persons with chronic indwelling bladder catheters will invariably have urine that harbors bacteria (often more than one species or strain) but have no clinical symptoms (asymptomatic bacteriuria) and thus requires no treatment. Thus, management of nursing home residents with bacteriuria, whether it be a true UTI, can often be difficult and perplexing.
Several surveys in long-term care facilities indicate that the prevalence of bacteriuria (asymptomatic bacteriuria and UTI) for women ranges from 15% to 57% (average, 36%) and for men ranges from 13% to 37% (average, 25%).45,46 It is, therefore, quite obvious that finding bacteria in the urine of nursing home residents is a very common finding. Numerous studies have demonstrated that antimicrobial therapy of asymptomatic bacteriuria in elderly persons in institutional or noninstitutional settings has no clinical benefits, ie, no reduction in mortality, acute episodes of symptomatic infection (UTI), or change in genitourinary symptoms.47-49 Moreover, there is an increased risk of new infection, adverse effects from antimicrobial therapy, costs of care, and more resistant organisms with treatment of asymptomatic bacteriuria. The challenge for the clinician will be how to diagnose UTI (vs asymptomatic bacteriuria) and whether to treat a nursing home resident with bacteriuria.
Clinical Definition of UTI and Specimen Collection. To justify obtaining a urinalysis and urine culture in a resident suspected of UTI or urosepsis, the criteria or definition for UTI in this setting should be present as described in Table 5.18,31 Diagnostic urine studies are not warranted in residents with asymptomatic bacteriuria.18
Collect a midstream or clean-catch specimen from elderly men who are functionally capable and cooperative; for other men use a condom external collection system to obtain a urine sample.18 Some elderly women may be able to provide a midstream urine specimens; however, female nursing home residents will often require an in-and-out catheterization to collect urine for studies. In residents with chronic indwelling bladder catheters, replace the old catheter with a new sterile catheter (old catheter is colonized with organisms).50,51 Aspirate urine from the catheter port; do not collect urine from the drainage bag, which is heavily contaminated with organisms.
Send the urine specimen to the laboratory for urinalysis and culture. Urinalysis should include leukocyte esterase and microscopic examination for white blood cells to determine presence of pyuria.18 More than 90% of elderly residents of long-term care facilities with asymptomatic bacteriuria or UTI will have pyuria.52 If pyuria is not present (negative leukocyte esterase test and < 10 white blood cells per high-power field of spun urine), the likelihood of bacteriuria being present is very low and thus a urine culture is unnecessary.53 If pyuria is present by either the leukocyte esterase test or microscopic examination, the urine can then be set up for culture and sensitivity tests.
Obtain blood cultures only if the resident appears bacteremic or septic; transfer the patient then to an acute hospital.
Etiology and Treatment. Again, do not treat nursing home residents with asymptomatic bacteriuria with or without an indwelling catheter.
The uropathogens causing asymptomatic bacteriuria or UTI in nursing home residents tend to be more diverse than those isolated from community-dwelling older adults or younger populations.45,46 Nevertheless, Enterobacteriaceae organisms are the most frequent infecting organisms in this population.45,46 Escherichia coli and Proteus mirabilis are the dominant pathogens in both women and men in nursing homes, but other Gram-negative bacilli such as Klebsiella spp, Enterobacter spp, Pseudomonas aeruginosa, and Providentia stuartii are also commonly isolated. Elderly men appear to have a higher propensity to be infected with Gram-positive organisms including coagulase-negative staphylococci and Enterococcus spp. Residents with chronic indwelling catheters will often have polymicrobial bacteriuria, with 25% showing enterococci as one of the causative organisms.45,50
With the exception of those residents who appear bacteremic or septic, most cases of UTI can be treated in the nursing home. The decision on which antibiotic to select will be dependent on whether the resident can take oral medications, antimicrobial sensitivity of the organism, and drug tolerance or allergies of the resident. Because of the wide variety of oral antibiotics now available, most UTIs can be effectively treated by administering the drug(s) orally. Begin trimethoprim-sulfamethoxazole, one double-strength (160/800 mg) tablet twice a day for most residents with UTIs. If organisms are resistant to this antibiotic or if there is drug intolerance, prescribe a fluoroquinolone. Select nitrofurantoin for lower UTI only (not effective in pyelonephritis). Prescribe amoxicillin-clavulanate if enterococci or other Gram-positive cocci are suspected or isolated. If oral antibiotics are not feasible, prescribe an intramuscular agent. Long-acting cephalosporins or once-daily injections of an aminoglycoside are appropriate selections provided the organism(s) is (are) susceptible and the patient has no contraindications to these agents (eg, avoid aminoglycosides in residents with renal failure). Discontinue intramuscular injections once oral medications can be tolerated. For catheter-related UTI, selection of antibiotics will be highly dependent on culture and sensitivity results. If empirical therapy is required for catheter-related UTI, prescribe amoxicillin-clavulanate plus a fluoroquinolone until microbiology data become available—then adjustment in drug(s) should be made if appropriate. Table 6 summarizes some of the recommended antibiotics for UTIs in nursing home residents.
Although good studies defining duration of treatment for UTI in this population are lacking, most nursing home residents who are not severely ill should receive 7-10 days of antibiotics. Prescribe antibiotics for 10-14 days in elderly men, those residents with more severe infections, and residents with recurrent UTI.45,46 In some men with repeated episodes of UTI, treatment may require extension to 6-12 weeks.54 Treat residents with catheter-related UTI for approximately 7 days. The goal with catheter-related UTI is to improve clinical symptoms and not maintenance of a sterile urine (since bacteriuria will return in chronically catheterized individuals). Repeat urine studies following completion of treatment ("test of cure") has not been routinely recommended because of the lack of data to determine its cost effectiveness.
Infected Pressure Ulcer
Epidemiology and Pathogenesis. Pressure ulcers are common in nursing home residents. The incidence/prevalence of pressure ulcers depends on the population studied, definition of the pressure ulcer, and what stage of pressure ulcer is considered.55 The 4 stages of pressure ulcers are defined in Table 7. Most epidemiological studies survey pressure ulcers of stage II or higher. Using this criterion, the prevalence of pressure ulcers in nursing home residents varies from a low of 1.2% to as high as 11.3%.56,57 However, if stage I ulcers are included, the prevalence can be as high as 30%. It is beyond the scope of this review to discuss in detail the risk factors and pathogenesis of pressure ulcers. Clearly external pressure on any surface of the body is the primary mechanism for developing pressure ulcers. Factors that predispose a person to be exposed to prolong pressure, compromise skin integrity, or reduce healing of skin increase the risk for pressure ulcers. Examples of these factors include immobility, altered consciousness, increased age, diabetes mellitus, friction, and shear forces at the skin surface, poor nutrition, and urinary incontinence.55
The primary complication of pressure ulcers is infection. Infection delays wound healing and may lead to more serious complications such as osteomyelitis (15-25% of patients with nonhealing ulcers) and bacteremia (mortality as high as 51%). The pathogens causing infected pressure ulcers are primarily those of the skin flora in early lesions and fecal flora in more chronic or extensive ulcers. Streptococci and staphylococci are most often the pathogens causing cellulitis and superficial ulcers; enteric Gram-negative bacilli (E coli, Proteus spp, etc), enterococci and anaerobic bacteria (Peptostreptococcus spp, Bacteroides fragilis, etc) are the most frequently isolated organisms for chronic and deep pressure ulcers.62 At times, chronic stage II ulcers may harbor mixed aerobic and anaerobic bacteria.
Diagnosis. Diagnosing an infected pressure ulcer is complex because all ulcers become quickly colonized with organisms. Thus, simply isolating bacteria from the surface of the lesion does not confirm the presence of an infection. Moreover, a surface swab culture of the ulcer may not accurately reflect the true pathogens causing the infection below the surface of the lesion.
Table 8 provides clinical criteria for the diagnosis of an infected pressure ulcer. These findings should be present before any specific diagnostic and therapeutic interventions are contemplated.
Collect diagnostic microbiology specimens from purulent drainage or deep tissue biopsy (at the time of debridement), but do not use surface swabs for culture and sensitivity.63,64 Do not obtain blood cultures unless the nursing home resident needs to be hospitalized for this infection, ie, appears bacteremic or septic, there is evidence of osteomyelitis, or an associated cellulitis has failed to respond with local treatment and oral antibiotics. Carefully assess residents who have stage III or greater lesions for possible osteomyelitis, localized pockets of abscess, or dissection of infection to adjacent areas (eg, infected sacral pressure ulcer extending to lower extremity). Transfer these residents to an acute hospital for further diagnostic evaluation (blood cultures, x-rays, bone scan, magnetic resonance imaging, etc).
Treatment. Except for residents with bacteremia/sepsis, osteomyelitis, large abscesses, or unrelenting cellulitis while on treatment, most infected pressure ulcers can be managed in the nursing home setting. The most important aspect of treating pressure ulcers is to remove or reduce the pressure and associated risk factors. Local wound care with dressing changes and debridement is essential. Topical antibiotics or antiseptic agents are not recommended. Initiate antimicrobial therapy with a drug or drug combination that will be effective to the most likely pathogens. As with pneumonia and UTI, intramuscular injection is acceptable until oral medications can be administered. Table 9 lists recommended antibiotics for treatment of infected pressure ulcers in the nursing home setting according to route of administration and stage of lesions. Although there are no studies to determine the optimal duration of antibiotic therapy, the length of treatment will vary according to the stage of the ulcer and severity of infection. Treat most acute/early stage I or II ulcers for 10-14 days. For stage III or IV lesions, treat for 14-21 days or even longer depending on clinical response and involved tissue (eg, osteomyelitis requires more than 4 weeks of antibiotic treatment).
For residents requiring hospitalization, interventions may include surgery (major debridement, abscess drainage, reconstruction flaps), especially for stage III and IV lesions that are chronic and expanding. Once the clinical condition stabilizes, continuation of antibiotic treatment (eg,osteomyelitis) can be done in the nursing home.
References
1. U.S. Bureau of Census. Decennial censuses of population, 1900-1980 and projections of the population of the United States: 1982-2050 (advance report). Current Population Reports Series P-25, no. 922. Washington, D.C.: U.S. Bureau of Census, October 1982.
2. Kemper P, Murtaugh DM. Lifetime use of nursing home care. N Engl J Med. 1991;324:595-600.
3. Evans JM, et al. Medical care of nursing home care. Mayo Clin Proc. 1995;70:694-702.
4. Besdine RW, Rubenstein LZ, Cassel C. Nursing home residents need physician services. Ann Intern Med. 1994;120:616-618.
5. Castle SC. Clinical relevance of age-related immune dysfunction. Clin Infect Dis. 2000;31:578-585.
6. Castle SC. Impact of age and chronic illness-related immune dysfunction on risk of infections. In: Yoshikawa TT, Ouslander JG eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:33-50.
7. High KP. Micronutrient supplementation and immune function in the elderly. Clin Infect Dis. 1999;28:717-722.
8. High KP. Nutrition and infection. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:57-70.
9. Yoshikawa TT. Epidemiology and unique aspects of aging and infectious diseases. Clin Infect Dis. 2000;30:931-933.
10. Keating MJ III, et al. Effect of aging on the clinical significance of fever in ambulatory adult patients. J Am Geriatr Soc. 1984; 32:282-287.
11. Norman DC. Fever in the elderly. Clin Infect Dis. 2000;31:148-151.
12. Norman DC. Clinical manifestations of infection. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:71-78.
13. Castle SC, et al. Fever response in elderly. Are the older truly colder? J Am Geriatr Soc. 1991;39:853-857.
14. Castle SC, et al. Lowering the temperature criterion improves detection of infections in nursing home residents. Aging Immunol Infect Dis. 1993;4:67-76.
15. Norman DC, Yoshikawa TT. Fever in the elderly. Infect Dis Clin North Am. 1996;10:93-99.
16. Yoshikawa TT, Norman DC. Infection control in long-term care. Clin Geriatr Med. 1995;11:467-480.
17. Weinberg AD. Evaluation of infections in long-term care facilities versus acute care hospitals. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:15-25.
18. Bentley, et al. Practice guideline for evaluation of fever and infection in long-term care facilities. Clin Infect Dis. 2000;31: 640-653.
19. Setia U, et al. Bacteremia in a long-term care facility. Arch Intern Med. 1984;144:1633-1635.
20. Muder RR, et al. Bacteremia in a long-term care facility: A five-year prospective study of 163 consecutive episodes. Clin Infect Dis. 1992;14:647-654
21. Alvarez S, et al. Nosocomial infections in long-term facilities. J Gerontol. 1988;43:M9-M17.
22. Dumyati G, Falsey AR. Influenza and other respiratory viruses. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:197-222.
23. Schmader K, Twerksy J. Herpes zoster, cellulitis, and scabies. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:283-303.
24. Akhtar AJ. Infectious diarrhea. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:305-312.
25. Simor AE, Yake SL, Tsimidia K. Infection due to Clostridium difficile among elderly residents of a long-term-care facility. Clin Infect Dis. 1993;17:672-678.
26. Harrington DW, Barrett PV. Hepatitis. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002: 313-336.
27. Chien NT, et al. Seroprevalence of viral hepatitis in an older nursing home population. J Am Geriatr Soc. 1999;47:1110-1113.
28. Rajagopalan S, Yoshikawa TT. Tuberculosis in long-term-care facilities. Infect Control Hosp Epidemiol. 2000;21:611-615.
29. Yoshikawa TT, Norman DC. Approach to fever and infection in the nursing home. J Am Geriatr Soc. 1996;44:74-82.
30. Wasserman M, et al. Utility of fever, white blood cells and differential count in predicting bacterial infections in the elderly. J Am Geriatr Soc. 1989;37:537-543.
31. McGeer A, et al. Definitions of infection for surveillance in long-term care facilities. Am J Infect Control. 1991;19:1-7.
32. Mylotte JM. Pneumonia and bronchitis. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002: 223-243.
33. Fried TR, Gillick MR, Lipsitz LA. Whether to transfer? Factors associated with hospitalization and outcomes of elderly long-term care patients with pneumonia. J Gen Intern Med. 1995;10: 246-258.
34. Naughton BJ, Mylotte JM. Treatment guideline for nursing home-acquired pneumonia based on community practice. J Am Geriatr Soc. 2000;48:82-88.
35. Medina-Walpole AM, Katz PR. Nursing home-acquired pneumonia. J Am Geriatr Soc. 1999;47:1005-1015.
36. Loeb M, et al. Risk factors for pneumonia and other lower airway respiratory tract infections in elderly residents of long-term care facilities. Arch Intern Med. 1999;159:2058-2064.
37. Drinka PJ. Pneumonia in a nursing home. J Gen Intern Med. 1994;9:650-652.
38. Marrie TJ, Durant H, Kwan C. Nursing home-acquired pneumonia: A case control study. J Am Geriatr Soc. 1986;34:697-702.
39. Yamaya M, et al. Interventions to prevent pneumonia among older adults. J Am Geriatr Soc. 2001;49:85-90.
40. Terpenning MS, et al. Aspiration pneumonia: Dental and oral risk factors in an older veteran population. J Am Geriatr Soc. 2001; 49:557-563.
41. Mandell LA, et al. Canadian guidelines for the initial management of community-acquired pneumonia: An evidence-based update by the Canadian Infectious Diseases Society and Canadian Thoracic Society. Clin Infect Dis. 2000;31:383-421.
42. Gleason PP, et al. Associations between initial antimicrobial therapy and medical outcomes for hospitalized elderly patients with pneumonia. Arch Intern Med. 1999;159:2562-2572.
43. Marrie TJ. Clinical strategies for managing pneumonia in the elderly. Clin Geriatr. (supplement) August 1999:6-10.
44. Nicolle LE, Strausbaugh LJ, Garibaldi RA. Infections and antibiotic resistance in nursing homes. Clin Microbiol Rev. 1996;9:1-7
45. Nicolle LE. Urinary tract infection. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:173-195.
46. Yoshikawa TT, Nicolle LE, Norman DC. Management of complicated urinary tract infection in older patients. J Am Geriatr Soc. 1996;44:1235-1241.
47. Nicolle LE, et al. Bacteriuria in elderly institutionalized men. N Engl J Med. 1983;309:1420-1425.
48. Nicolle LE, Mayhew WJ, Bryan L. Prospective randomized comparision of therapy and no therapy for asymptomatic bacteriuria in institutionalized elderly women. Am J Med. 1987;83:27-33.
49. Abrutyn E, et al. Does asymptomatic bacteriuria predict mortality and does antimicrobial treatment reduce mortality in elderly ambulatory women? Ann Intern Med. 1994;120:827-833.
50. Grahn D, et al. Validity of urine catheter specimen for diagnosis of urinary tract infection in the elderly. Arch Intern Med. 1985; 145:1858-1860.
51. Tenney JH, Warren JW. Bacteriuria in women with long-term catheters: Paired comparison of indwelling and replacement catheters. J Infect Dis. 1988;157:199-202.
52. Rodgers K, et al. Pyuria in institutionalized elderly subjects. Can J Infect Dis. 1991;2:142-146.
53. Norman DC, Yamamura R, Yoshikawa TT. Pyuria: Its predictive value of asymptomatic bacteriuria in ambulatory elderly men. J Urol. 1986;135:520-522.
54. Smith JW, et al. Recurrent urinary tract infection in men. Ann Intern Med. 1979;91:544-548.
55. Livesly N, Chow AW. Infected pressure ulcers. In: Yoshikawa TT, Ouslander JG, eds. Infection Management for Geriatrics in Long-Term Care Facilities. New York, NY: Marcel Dekker; 2002:257-281.
56. Brandeis GH, et al. The epidemiology and natural history of pressure ulcers in elderly nursing home residents. JAMA. 1990;264: 2905-2909.
57. Allman RM. Pressure ulcer prevalence, incidence, risk factors, and impact. Clin Geriatr Med. 1997;13:421-437.
58. National Pressure Ulcer Advisory Panel. Pressure ulcers prevalence, cost, risk assessment: Consensus development conference statement. Decubitus. 1989;2:24-28.
59. Darouche RO, et al. Osteomyelitis associated with pressure ulcer. Arch Intern Med. 1994;154:753-758.
60. Sugarman B. Pressure ulcers and underlying bone infection. Arch Intern Med. 1987;143:553-555.
61. Bryan CS, Dew CE, Reynolds KL. Bacteremia associated with decubitus ulcers. Arch Intern Med. 1983;143:2093-2095.
62. Chow AW, Galpin JE, Guze LB. Clindamycin for treatment of sepsis caused by decubitus ulcers. J Infect Dis. 1977;135(suppl): 565-568.
63. Sapico FL, et al. Quantitative microbiology of pressure ulcers in different stages of healing. Diagn Microbiol Infect Dis. 1986; 5:31-38.
64. Rudensky B, et al. Infected pressure sores: Comparison of methods for bacterial identification. South Med J. 1992;85: 901-903.
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