Infectious Disease 1 Flashcards
PT implications for studying infectious disease
- infections must be treated effectively to allow full recovery and allow the patient to progress in rehab
- allow them to fully engage in PT
- side effects may impair fxn and limit performance
- prevent infection and control transmission
Signs and Symptoms of infectious disease
Box 8.1?
fever, chills, malaise (earliest symptoms) sweating, nausea and vomiting, lymph node swelling
increasing number of leukocytes or a change in the types of leukocytes
WBC response to infectious disease
leukocytosis (increase due to infection or inflammation)
leukopenia (decrease due to bone marrow disease, radiation, chemo or meds, inc risk of patients being infected)
Neutropenia
Neutropenia
neutrophils are most abundant WBC
a reduction of them increases the risk of nosocomial infections (healthcare-associated infections, HAI)
Normal WBC count levels
Normal - 5000-10000
> 10000 leukocytosis
< 4000 leukopenia
Normal body temp (how does it differ for older adults?)
96.8-99.5 (avg of 98.6)
lower values for older adults
What controls body temp?
Hypothalamus is temperature-regulating center
Pyrogens - protein substances and toxins cause the set point of the hypothalamic thermostat to rise
This activates the hypothalamus to conserve heat and increase heat production
Is fever always due to infectious disease?
No, it may accompany inflammation, neoplastic, and immunologically mediated diseases
Infectious causes of fever (Box 8.2)
UTI, Respiratory infection, catheter-relates infection, surgical wound infection, infected pressure wounds, (also colitis, peritonitis, meningitis)
Noninfectious causes of fever (Box 8.2)
injured or abnormal cells incite production of pyrogens
drug reaction
pulmonary emboli
neoplasm
tissue necrosis (stroke, MI)
autoimmune diseases
Intermittent fever
temperature returns to normal at least once every 24 hours
sepsis, abscesses, infective endocarditis
Remittent fever
temperature fluctuates but does not return to normal
viral upper respiratory infections
sustained or continuous fever
temperature remains above normal with minimal variation
recurring or relapsing fever
episodic fevers lasting 1 to 3 days with 1 or more days of normal temperatures between episodes
What occurs to some people who have serious infections?
Do not initially develop a fever but develop tachypneic, become confused, or develop hypOtension
most common in older adults or those with HAI
Other signs and symptoms of infectious disease
abscess (pus collection that if ruptured or drained into other tissues can cause spread of infection)
rash with fever - caused by any microbe that penetrates stratum corneum, skin lesions
red streaks - develop in direction of regional lymph nodes (acute lymphangitis), bacteria may enter blood stream, often swelling of lymph nodes
inflamed lymph nodes - in acute infection, nodes are tender, asymmmetric and enlarged, and overlaying skin may be red and warm
joint effusion - accumulation of excess fluid in a joint, associated with infectious arthritis
Why are older adults more susceptible to infectious diseases
- increases susceptibility due to immunoescnece and comorbidities
- increased morbidity and mortality, especially in frail and debilitated older adult
- decrease in number of naive T cells and increase in memory T cells
- slower to response and require a stronger stimulus
What specific part of the immune system is impacted most by aging?
As thymus ages, decrease number of naive T cells released, = decreased diversity and proliferation rate = difficulty responding to antigens especially viruses and ability to stimulate B cells to make antibodies
What factors outside the immune system can cause increased susceptibility for older adults?
- atrophic skin more easily damaged
- decreased cough and gag reflex make it harder to control secretions
- decreased bronchiolar elasticity and mucociliary activity (doesn’t clear mucus that’s catching pathogens)
- denture associated infections
- more likely to have implanted device
Why do we have to be extra careful when working with older adults?
Symptoms of infection is often VAGUE, BLUNTED OR ATYPICAL
More serious infections may occur yet with little or no fever because of an impaired thermoregulatory system or masking effects of drugs
^ Lower threshold of temperature for infection should be used (99 or 100)