Infections in the Elderly Part 1 Karen Greenberg, DO

Infections in the ElderlyPart 1

Karen Greenberg, DO

Infections in the ElderlyPart 1

This Care of the Aging Medical Patient in the Emergency Room (CAMPER) presentation is offered by the Department of Emergency Medicine in coordination with the

New Jersey Institute for Successful Aging.This lecture series is supported by an educational

grant from the Donald W. Reynolds Foundation Aging and Quality of Life program.

Overview

• Recognizing and treating infections in the elderly patient can be particularly challenging because symptoms are often quite subtle and atypical in older adults.

• In this session, the emergency medicine resident will learn how to:

Overview

• Recognize common atypical presentations of various geriatric infections

• Institute treatment in the elderly with respect to medication dosing and drug interactions

• Identify admission criteria and appropriate transitioning of care from the Emergency Department

Question 1An 82 year old male presents from home with his wife. The patient is complaining of shaking chills and fever of 101 prior to arrival in the ED. The patient just finished a 10 day course of penicillin yesterday for a salivary gland infection. In the ED his only complaint is left flank pain. Which of the following does NOT place the patient at increased risk for infection?

a)History of sarcoid and taking prednisoneb)History of urostomy bag for 11 yearsc)Daily Exercised)Decreased cough reflexe)Malnutrition

Question 2A 91 year old female presents from a nursing home with change in mental status. Vital signs are temperature 101.8, BP 77/40, HR 85, RR 16, and pulse ox 92% room air. Per patient’s niece, the patient has not been eating well, has a nonproductive cough, and has a foley catheter in place for 2 months secondary to history of urinary retention. Which of the following organisms is the least likely cause of infection in this patient?

a)Enterococcus UTIb)Enterovirusc)S. aureus pneumoniad)S. pneumo meningitise)MRSA cellulitis

Question 3

A 71 year old male presents with confusion for the past 2 hours. Per the patient’s wife, he was complaining of chest pain at home and she called 911. Vital signs in the ED are BP 220/110, HR 120, Temperature 99.6, RR 16, and pulse ox 93% room air. Of the following lab tests, which is associated with a greater mortality rate during hospitalization?

a)WBC 15,000 mcLb)Serum creatinine 1.5 mg/dLc)BUN 45 mg/dLd)Lipase 150 Units/Le)Lactate level 3.6 mmol/L

Introduction

• By 2020, patients aged 65 years old and older will constitute 16.3% of the population.

• Already, they account for over 15 million ED visits each year, and a large percentage of these visits are related to infection.

Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.

Introduction

• Fever is present in 10% of all elderly ED patients.

• The elderly account for 65% of ED patients with sepsis.

• Elderly patients are at significantly greater mortality risk for a given infection than are younger adults.


Introduction

• Elderly patients have three times the mortality from pneumonia and five to ten times the mortality from urinary tract infection when compared with younger adults.

• These statistics make appropriate evaluation and treatment of the infected elderly an essential skill.


Introduction

• The clinical presentation of infection in the elderly is often atypical, subtle, and elusive.

• This makes early diagnosis and initiating treatment a challenge.

• Elderly may not only have fewer symptoms, but might present with nonspecific consequences of infection that on the surface appear unrelated.

Introduction

• Examples on nonspecific symptoms:- Generalized malaise- Falls- Changes in mental status or cognitive

impairment- Anorexia

Introduction

• The classical manifestation of infection, fever, and leukocytosis, may be absent or blunted in 20-30% of serious elderly infections.

• In contrast to the young where fever is commonly attributed to a viral process, in the elderly it is associated with severe bacterial infections.

Adedipe A, Lowenstein R. Emerg Med Clin N Am 2006; 24(2):433-448.

Introduction

• It is important to note that criteria for fevers in the elderly are unique, and include elevations in body temperature from baseline of 1.1 °C or greater.

• Furthermore, hypothermia, a decrease in body temperature, is not an uncommon presentation of an underlying serious infection.

Risk Factors

• Aging is associated with:- numerous chronic illnesses and

comorbid conditions- polypharmacy and immunosuppressive

medications- changes in the immune system that

include a reduction of T-lymphocyte function and cell-mediated immunity

Risk Factors

• There is an impairment of the normal physiologic reserves seen in the elderly:- decreased cough reflex leading to aspiration

pneumonia- impaired arterial and venous circulation- compromised wound healing, making cellulitis

a common infection

Risk Factors

• Living environments, such as assisted living facilities and nursing homes, allow for the development of infection and foster the transmission of infectious agents.

• These facilities contribute to the rise and exposure of antibiotic-resistant bacteria (MRSA and VRE)

Risk Factors

• Invasive devices, which include indwelling urinary catheters, intravenous catheters, feeding tubes, and tracheostomies, are more common in the elderly.

• These devices compromise host defenses enabling bacteria to enter the body and cause infection.

Risk Factors

• Malnutrition, common in the nursing home population, is associated with a limited immune response and impaired wound healing.

• Polypharmacy is also frequently observed and can contribute to infection.

Question 1An 82 year old male presents from home with his wife. The patient is complaining of shaking chills and fever of 101 prior to arrival in the ED. The patient just finished a 10 day course of penicillin yesterday for a salivary gland infection. In the ED his only complaint is left flank pain. Which of the following does NOT place the patient at increased risk for infection?

a)History of sarcoid and taking prednisoneb)History of urostomy bag for 11 yearsc)Daily Exercised)Decreased cough reflexe)Malnutrition

Fever and Infection

• Elevated temperature is one of the most common complaints in the elderly and is present in approximately 10% of elderly ED visits.

• When fever is present, it is infectious in etiology approximately 90% of the time.


Fever and Infection

• Fever in elderly ED patients is most commonly bacterial in origin.

• In several studies, it has been due to a viral cause in less than 5% of cases.


Fever and Infection

• A temperature greater than 37.8 °C (100 °F) is associated with markers of serious illness over 75% of the time as determined by:- positive blood cultures- death within 1 month- the need for surgery or an invasive procedure- hospitalization for 4 or more days- the administration of IV antibiotics for 3 or

more days- a repeat ED visit within 72 hours


Fever and Infection

• Workup should include- CBC with differential- Urinalysis- chest radiograph- blood cultures- urine cultures- lactate

Lactate

• In patients with infections, increasing serum lactate values of > 2 mmol/L were linearly associated with relative risk of mortality during hospitalization, at 30 days, and at 60 days when compared to patients with serum lactate levels of < 2 mmol/L.³

Lactate

• Greater magnitude of association with mortality than either of two other commonly ordered laboratory tests, leukocyte count and serum creatinine.

• Higher ED lactate values are associated with greater mortality in a broad cohort of admitted patients over age 65 years, regardless of the presence or absence of infection.

del Portal DA, Shofer F, Mikkelsen ME, et al. Acad Emerg Med 2010;17(3):260-268.

Fever and Infection

• Also consider the possibility of other potentially serious causes of fever which are present 10% of the time:- rheumatologic disease- thyroid storm- environmental exposure- medication-related events- malignancy


Fever and Infection

• Although fever often signifies the presence of serious illness in elderly patients, severe infection may also be present in the absence of fever.

• The failure to mount a febrile response to infection has been particularly noted in nursing home patients.


Fever and Infection

• The most accurate definition of fever in the elderly may be a change in temperature from the patient’s baseline.

• Elderly ED patients with a temperature of 37.2°C (99°F) or higher, or with an increase of 1.3°C (2°F) from baseline should be considered to be febrile.


Question 2A 91 year old female presents from a nursing home with change in mental status. Vital signs are temperature 101.8, BP 77/40, HR 85, RR 16, and pulse ox 92% room air. Per patient’s niece, the patient has not been eating well, has a nonproductive cough, and has a foley catheter in place for 2 months secondary to history of urinary retention. Which of the following organisms is the least likely cause of infection in this patient?

a)Enterococcus UTIb)Enterovirusc)S. aureus pneumoniad)S. pneumo meningitise)MRSA cellulitis

Question 3

A 71 year old male presents with confusion for the past 2 hours. Per the patient’s wife, he was complaining of chest pain at home and she called 911. Vital signs in the ED are BP 220/110, HR 120, Temperature 99.6, RR 16, and pulse ox 93% room air. Of the following lab tests, which is associated with a greater mortality rate during hospitalization?

a)WBC 15,000 mcLb)Serum creatinine 1.5 mg/dLc)BUN 45 mg/dLd)Lipase 150 Units/Le)Lactate level 3.6 mmol/L

Bacteremia

• The presence of bacteremia in elderly patients with infection signifies a more severe disease state and greater risk of mortality.

• Blood stream infection is among the top ten causes of death in elderly patients in the U.S.


Bacteremia

• Risk factors:- increasing age- comorbid diseases:

diabetes cardiovascular disease neuropsychiatric disease malignancy stroke

- recent invasive procedure or instrumentation

- presence of indwelling catheters

Bacteremia

• Elderly patients with diabetes have twice the rate of bacteremia as those without.

• Although fever is generally considered one of the cardinal signs of infection, numerous studies have demonstrated than an elevated temperature is often not present in elderly patients with blood stream infection.

Bacteremia

• As a result, the absence of fever cannot be taken as proof of the absence of bacteremia in this patient population.

Bacteremia

• The only independent predictors of bacteremia:- altered mental status- vomiting- WBC band forms greater than 6%


Bacteremia

• Elderly patients are likely to present with nonspecific signs and symptoms.

• Among the most common presenting symptoms of bacteremia in the elderly are altered mental status, confusion, weakness, falls, and decreases in functional status.


Bacteremia

• Laboratory testing fails to provide diagnostic certainty.

• Among the elderly with bacteremia, 20%-45% will have a normal WBC count.

• Relying on an increase in the erythrocyte sedimentation rate is also insensitive for the diagnosis of bacteremia in the elderly.


Bacteremia

• The etiology of bacteremia is heavily influenced by patient-specific factors:- indwelling lines: skin source- indwelling catheters: urinary source- altered mental status or impaired gag

reflex: pulmonary source

Bacteremia

• Urinary tract sources are the most common overall, even in the absence of indwelling urinary devices.

• They account for 25%-55% of bateremia in elderly patients presenting to the ED.


Bacteremia

• Lower respiratory infection: 10-34%• Unknown source:11-31%• Intra-abdominal source: 9-20%• Skin or catheter-related source: 9%


Bacteremia

• Gram-negative organisms: 70% cases

• Gram-positive organisms: 25% cases• Anaerobes: < 10% cases• Polymicrobial infections: 5-17%


Bacteremia

• Escherichia coli is the most commonly isolated organism (22-54%)

• Other causative gram-negative organisms include Klebsiella pneumoniae (8-16%) and Pseudomonas (4-14%).

Bacteremia

• Gram-positive organisms include:- Streptococcus pneumoniae (4-20%)- Staphylococcus aureus (4-14%)- Enterococcus (3-9%)- Streptococcus viridans (4%)

Bacteremia

• The likelihood of Staphylococcus aureus bacteremia is increased in residents of long-term care facilities, particularly residents with nursing home-associated pneumonia or skin and soft-tissue infections.

• It is less common in patients dwelling in the community.


Bacteremia

• Bacteremia in the elderly is associated with high mortality rates.

• Overall rates have been 20%-37% in most studies.


Pneumonia

• In the United States, pneumonia and influenza rank 6th among the leading causes of death.

• With advanced age, rates of morbidity and mortality for pneumonia increase dramatically.


Pneumonia

• Nearly half of all cases of pneumonia involve patients > 65 years of age.

• Among nursing home residents, pneumonia is the second most common cause of infection.

• It is also the second most common cause of bacteremia in a nursing home.


Pneumonia

• Several factors associated with the aging process of the respiratory tract and lung tissue predispose older people to respiratory infections.

• Changes in the mucociliary transport system associated with age and smoking have a negative effect with clearing of bacterial pathogens.

Pneumonia

• Changes in lung capacity, elasticity, and compliance are common with age.

• Most cases are in fact related to microaspiration of bacterial pathogen colonizing the oropharynx.

• Ineffective clearing of mucus and secretions from the respiratory tract makes patient more susceptible to aspiration pneumonia.


Pneumonia - Microbiology

• Streptococcus pneumoniae- most common isolate from sputum culture (20-30% of

CAP cases in the elderly).- most common pathogen found in nursing home

residents.



• Haemophilus influenza- either encapsulated H influenza type B

or the unencapsulated strains- patients have chronic lung disease- patients are usually male- present with productive cough


• Legionella pneumophilia- infections tend to occur sporadically.- infections usually appear in the summer

and fall.- may be found in the water condensed

from air conditioning systems.



• Mycoplasma pneumoniae- common atypical pathogen causing

pneumonia in patients under 60 years of age.

- elderly patients have a somewhat lower proportion of cases of atypical infections compared with younger, healthier patients.



• Staphylococcus aureus- more commonly associated with nosocomial

infection- causes multilobar infiltration.- frequently associated with bacteremia.- well-known manifestation of S aureus infection is

the florid onset of pneumonia following recovery from influenza.



• Gram-Negative Bacilli- rare in younger patients- more likely to affect nursing home

residents compared with community dwellers

- nearly 12% of pneumonias in patients from nursing homes

Pneumonia

• Classically, cough, especially productive cough, and fever are the hallmarks of respiratory tract infections.

• Other clinical manifestations of pneumonia include pleurisy and rigors.

• In the elderly patient the clinical presentation is similar; however, the rates of patients presenting with these manifestations change.

Pneumonia

• Although nearly 60% of patient with community-acquired pneumonia (CAP) presented with cough, only 34% of nursing home patients were noted to have a cough in the setting of pneumonia.

• Confounding this picture is the fact that only 60-75% of nursing home patients are febrile on presentation.


Pneumonia

• The initial workup of patients with respiratory infections includes:- pulse oximetry- chest radiograph- CBC with differential- blood cultures- serum electrolytes, including BUN

Pneumonia

• Chest radiography remains the “gold standard” for diagnosis of pneumonia.

• Serum chemistries have little impact on patient outcome; however, the calculation of creatinine clearance may influence the provider’s choice and dose of antibiotic therapy.


Community-acquired Pneumonia in the Elderly

• The etiology of CAP pneumonia in the elderly is similar to that in young patients.

• Strep pneumoniae is the most common etiologic agent, accounting for approximately 50% of cases.

• Haemophilus influenzae and Moraxella catarrhalis are also relatively common.



• Atypical agents such as Chlamydia pneumoniae, Mycoplasma, and Legionella pneumophilia are seen approximately 15% of the time in community-dwelling elderly persons, a lesser percentage than in younger patients.



• Enteric gram-negative rods and Staphylococcus aureus are rarer pathogens and are more likely to be seen in the most severely ill patients.

• CAP developing after viral influenza has an increased chance of being caused of S aureus.


Nursing Home – and other Health Care – associated Pneumonias

• NHAP is clinically distinct from CAP in the elderly.

• It is associated with increased comorbidity, poorer functional status, and greater mortality.

• The mortality rate is 19-53% as compared with 8-14% in CAP.


Definition of HCAP

1) Hospital-acquired pneumonia (HCAP): pneumonia not present at admission that develops 48 hours or more after hospitalization.

2) Ventilator-associated pneumonia (VAP): pneumonia occurring 48-72 hours after endotracheal intubation.


Definition of HCAP

3) Health care-associated pneumonia (HCAP): pneumonia occurring in the presence of any of the following:

- Residence in a nursing home or long-term care facility

- Receipt of intravenous antibiotics, chemotherapy, or wound care within the preceding 30 days

- Hospitalization in an acute care setting for 2 or more days in the preceding 90 days

- Attendance at a hemodialysis clinic


HCAP

• Strep pneumoniae is still the most common organism, however enteric gram-negative rods, anaerobes, and Staph aureus are much more common in these patients.

• Pseudomonas rates have been 4-25% but as high as 52%.


HCAP

• Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniae, and atypical agents are much rarer than in the community-dwelling population.


Pneumonia – TreatmentCAP

• Elderly patients who develop CAP should receive:- a second-generation cephalosporin plus

a macrolideor- a nonpseudomonal cephalosporin plus a

macrolideor- monotherapy with a flouroquinolone


Pneumonia – TreatmentNHAP/HCAP

• Patients from nursing care facilities require appropriate antibiotic regimens to adequately cover multi-drug resistant organisms.

• Ideally antibiotic choice will include 2 drugs for gram-negative coverage as well as a drug for MRSA.


• The first gram-negative drug should be:- an anti-pseudomonal cephalosporin

(cefepime or ceftazidime)- an anti-pseudomonal carbapenem

(imipenem or meropenem) or- an anti-pseudomonal beta-lactam

inhibitor (piperacillin-tazobactam)Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.


• The second gram-negative drug should be:- an aminoglycoside (amikacin,

gentamicin, or tobramycin) or- an anti-pseudomonal

fluoroquinolone (ciprofloxacin or levofloxacin)



• If MRSA is a concern, vancomycin or linezolid is recommended.


Urinary Tract Infection

• Urinary tract infections (UTIs) encompass a spectrum of disease, from asymptomatic bacteriuria and cystitis, to pyelonephritis and urosepsis.

• UTIs are among the most common infections affecting the elderly.



• Among otherwise healthy geriatric patients living in the community, rates of UTI range from 5-30%, with higher rates seen with advanced age.

• Among institutionalized patients, the prevalence rates increase remarkably, between 17-55% of women and 15-31% of men.



• Anatomic variations during the aging process increase the risk of UTIs:- changes in prostatic function in men.- changes in vaginal flora associated with

menopause in women.- elderly patients are more likely to have

obstructive uropathy or anatomic changes related to childbirth or reproductive surgery.Adedipe A, Lowenstein R. Emerg Med Clin N Am 2006; 24(2):433-448.


• Other factors to consider include:- higher rates of incontinence- more frequent urologic

instrumentation- higher rates of catheterization- comorbid diseases- medications that alter bladder

functionAdedipe A, Lowenstein R. Emerg Med Clin N Am 2006; 24(2):433-448.


• Among young, healthy patients, the vast majority of UTIs are a result of Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterococcus, Pseudomonas, and Staphylococcus species.

• Elderly patients have a lower incidence of E coli infection and higher rates of polymicrobial infections.



• Patients with short-term urinary catheters are typically infected by a single organism, while long-term catheters are associated with polymicrobial infections.

• The prevalence of gram-positve UTIs in geriatric patients has been increasing.



• The elderly often present with atypical symptoms of UTI:- malaise- anorexia- weakness- subtle mental status changes



• Delirium and functional decline may be the first signs of bacteremia from a urologic source.

• Such “nonurinary” symptoms are more likely to occur in patients with existing comorbities including dehydration.



• Urine microscopy and culture make the ultimate diagnosis.

• Although urine cultures are rarely helpful for the emergency physician, they help tailor the antibiotic regimen after an initial antibiotic has been started.

Urinary Tract Infection Treatment

• Broad antibiotic coverage for a longer duration should be the cornerstone of any treatment plan.

• 7-10 days of treatment is preferred for women with symptoms for longer than 1 week, women with structural of functional changes, and for all men.²

• 14 days of treatment should be routine for elderly patients with pyelonephritis.Adedipe A, Lowenstein R. Emerg Med Clin N Am 2006; 24(2):433-448.


• Treatment of uncomplicated community-acquired UTI in the elderly is generally with a fluoroquinolone.

• Due to increased rates of resistance, TMP-SMX is not preferred as an empiric first-line agent.



• Trimethoprim-Sulfamethoxazole (TMP-SMX) may be given to elderly women when the sensitivities are confirmed; however, there is a higher incidence of side effects and discontinuation when compared with fluoroquinolones.



• Alternative intravenous antibiotic therapies include:- a fluoroquinolone- gentamicin plus or minus ampicillin - a third-generation cephalosporin plus or

minus an aminoglycoside



• Selecting the optimum treatment for UTIs acquired in a long-term care facility or in the presence of other complicating factors is more difficult due to the high prevalence of resistant organisms.


• A fluoroquinolone should generally be considered although only cautiously used as monotherapy due to increased rates of resistance in these patient populations.

• In these cases, empiric fluoroquinolone monotherapy may be less preferred than combination therapy.



• Alternative or additional therapies may include:- aminoglycosides plus or minus

ampicillin- anti-pseudomonal beta-lactams or- an anti-pseudomonal carbapenem



• Patients who have an increased risk of drug-resistant organism or who are moderately to severely ill should be strongly considered for initial two-drug therapy to ensure effectiveness of the empiric regimen.


• In patients with UTIs associated with chronic indwelling catheters, replacement of the catheter is associated with improved clinical outcomes and should be undertaken in the emergency department.


Summary

• Evaluation and management of the elderly patient with infection in the ED presents several challenges to the emergency physician.

• Elderly patients often present without classic signs and symptoms of infection, requiring vigilance in the face of nonspecific symptoms such as confusion or decreased functional status.

Summary

• These patients are at higher risk of poor outcomes than are younger adults.

• They are also at greater risk of infection with resistant organisms, necessitating the empiric use of broad-spectrum antimicrobial agents.

Summary

• Consideration of these unique aspects of the infected elderly patient will aid the emergency physician in providing optimal care to this at-risk patient population.

References

1. Caterino JM. Evaluation and management of geriatric infections in the emergency department. Emerg Med Clin N Am 2008;26(2):319-343.

2. Adedipe A, Lowenstein R. Infectious emergencies in the elderly. Emerg Med Clin N Am 2006; 24(2):433-448.

3. del Portal DA, Shofer F, Mikkelsen ME, et al. Emergency department lactate is associated with mortality in older adults admitted with and without infections. Acad Emerg Med 2010;17(3):260-268.

Documents

Infections in the Elderly Part 1 Karen Greenberg, DO