Chapter 28 – Infection Protection and Control (continued)
Vascular and Cellular Responses
- Acute inflammation is an immediate response to cellular injury.
- Increase in local blood flow causes redness and localized warmth
- Body releases chemical mediators that increase permeability of small blood vessels, and fluid,
protein and cells center interstitial spaces; this accumulation of fluid appears are localized
swelling or edema
- Pain is another sign of inflammation; caused by swelling of tissues causes increased pressure on
verve endings
- Through the process of phagocytosis, process of destroying and absorbing bacteria, specialized WBCs,
called neutrophils and monocytes, ingest and destroy microorganisms. If inflammation is systemic, other
symptoms develop. Leukocytosis, or an increase in the number of circulating WBCs, is the response of
the body to WBCs leaving blood vessels.
- In the adult a serum WBC count is normally 5,000 to 10,000/mm3 but typically rises to 15,000
to 20,000/mm3 and higher during inflammation.
Inflammatory Exudate
- Exudate may be serous (clear, like plasma), sanguineous (containing red blood cells), or purulent
(containing WBCs and bacteria). Usually the exudate is cleared away through lymphatic drainage.
- Caused by collection of fluid, dead tissue cells and WBCs
Tissue Repair
- New cells undergo gradual maturation until they take on the same structural characteristics and
appearance as previous cells
- If inflammation was chronic, new tissue fill with fragile granulation tissue that eventually takes form of
a scar
Health care-associated infections
- Health care–associated infections (HAIs) result from the delivery of health services in a health care
agency. They occur as the result of invasive procedures, antibiotic administration, the presence of
multidrug-resistant organisms (MDROs), and breaks in infection prevention and control activities.
- Examples: unsterile insertion of urinary catheter, improper skin preparation before surgery,
contaminated respiratory therapy equipment, contaminated needles
* Increase cost of healthcare
- Can be exogenous or endogenous
- Exogenous: comes from microorganisms found outside the individual such as Salmonella
- Endogenous: occurs when part of patient’s flora becomes altered and an overgrowth occurs
such as staphylococci or yeasts; often when patient receives broad-spectrum antibiotics that alter
normal flora or when flora from one area moves to another
- Iatrogenic infection: type of HAI caused by invasive diagnostic or therapeutic procedure such as
bronchoscopy and treatment with broad-spectrum antibiotics increase risk for specific infections
Factors influencing infection prevention and control
- Age
- Sex: Estrogens promote (but androgens suppress) immune responses during infections and after
vaccination. They also increase the risk for autoimmune diseases
- Nutritional Status: A reduction in the intake of protein and other nutrients such as carbohydrates and
fats reduces body defenses against infection and impairs wound healing