Infections in the Elderly Part 1

1. Infections in the ElderlyPart 1 Karen Greenberg, DO

2. 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.

3. 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:

4. 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

5. Question 1 An 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? • History of sarcoid and taking prednisone • History of urostomy bag for 11 years • Daily Exercise • Decreased cough reflex • Malnutrition

6. Question 2 A 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? • Enterococcus UTI • Enterovirus • S. aureus pneumonia • S. pneumo meningitis • MRSA cellulitis

7. 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? • WBC 15,000 mcL • Serum creatinine 1.5 mg/dL • BUN 45 mg/dL • Lipase 150 Units/L • Lactate level 3.6 mmol/L

8. 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.

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

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

11. 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.

12. Introduction • Examples on nonspecific symptoms: • Generalized malaise • Falls • Changes in mental status or cognitive impairment • Anorexia

13. 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.

14. 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.

15. 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

16. 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

17. 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)

18. 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.

19. 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.

20. Question 1 An 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? • History of sarcoid and taking prednisone • History of urostomy bag for 11 years • Daily Exercise • Decreased cough reflex • Malnutrition

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

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

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

24. Fever and Infection • Workup should include • CBC with differential • Urinalysis • chest radiograph • blood cultures • urine cultures • lactate

25. 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

26. 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.

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

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

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

30. Question 2 A 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? • Enterococcus UTI • Enterovirus • S. aureus pneumonia • S. pneumo meningitis • MRSA cellulitis

31. 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? • WBC 15,000 mcL • Serum creatinine 1.5 mg/dL • BUN 45 mg/dL • Lipase 150 Units/L • Lactate level 3.6 mmol/L

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

33. Bacteremia • Risk factors: • increasing age • comorbid diseases: • diabetes • cardiovascular disease • neuropsychiatric disease • malignancy • stroke • recent invasive procedure or instrumentation • presence of indwelling catheters

34. 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.

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

36. Bacteremia • The only independent predictors of bacteremia: • altered mental status • vomiting • WBC band forms greater than 6% Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.

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

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

39. 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

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

41. Bacteremia • Lower respiratory infection: 10-34% • Unknown source: 11-31% • Intra-abdominal source: 9-20% • Skin or catheter-related source: 9% Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.

42. Bacteremia • Gram-negative organisms: 70% cases • Gram-positive organisms: 25% cases • Anaerobes: < 10% cases • Polymicrobial infections: 5-17% Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.

43. 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%).

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

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

46. Bacteremia • Bacteremia in the elderly is associated with high mortality rates. • Overall rates have been 20%-37% in most studies. Caterino JM. Emerg Med Clin N Am 2008;26(2):319-343.

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

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

49. 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.

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