CLASS 14 - INFECTION AND RELATED THERAPIES, SKIN + RESPIRATORY EXEMPLARS Flashcards
What is an infection?
The invasion and growth of foreign pathogens in the body.
Describe the chain of infection.
Infectious diseases result from the interaction of agent, host, and environment. Transmission occurs when the agent leaves its reservoir or host through a portal of exit, is conveyed by some mode of transmission, and enters through an appropriate protal of entry to infect a susceptible.
Identify the 4 types of pathogens that may cause an infection in the body.
Bacteria
Fungi
Virus
Parasite
What is pathogenicity? What does it depend on?
The ability to cause disease.
Pathogenicity depends on the microbes’ speed of reproduction and ability to bypass body defenses.
What are opportunistic pathogens?
Opportunistic pathogens rely on a suppressed immune system for successful infection.
Identify the 4 stages of infectious disease.
- Incubation Period
- Prodromal Period
- Acute Period
- Convalescent Period
What causes inflammation?
How does the process of inflammation impact a patient during an infection?
How can the inflammatory process negatively impact the body during an infection (excess inflammation)?
Inflammation occurs when chemicals from WBCs enter your blood or tissues. This raises the blood flow to the area of infection.
It can cause redness and warmth, and some chemicals cause fluid to leak into your tissues, resulting in swelling.
Excess inflammation is associated with tissue damage.
What is virulence?
Virulence is a measure of pathogenicity.
A highly virulent microbe can produce disease in very small numbers. The primary characteristics of virulence are invasiveness and toxicity.
Define invasiveness
Invasiveness is the ability to grow extremely rapidly and cause direct damage to surrounding tissue by sheer numbers.
How do bacterial exotoxins harm cells in the body?
Exotoxins damage or destroy body cells. When some gram-ve bacteria die, their cell wall releases endotoxins that induce macrophages to release large amounts of cytokines caysing rapid inflammation, fever, and chills.
What are subclinical infections?
If an infectious disease is subclinical, this means that it progresses from infection to resolution w/o the appearance of clinical symptoms.
What is bacteremia?
Bacteremia occurs when detectable amounts of bacteria enter the blood stream; usually asymptomatic, but can cause secondary infections particularly in the presence of cardiac valve disease or a prosthetic joint
Define sepsis.
What are the clinical manifestations?
Sepsis occurs when circulating bacteria cause systemic inflammation.
Signs include fever, hypotension, tachycardia, tachypnea, and leukocytosis.
Describe severe sepsis.
Severe sepsis includes all signs of sepsis + multi-organ failure.
What is septic shock?
What pathogens can cause septic shock in the body?
Septic shock is a combination of severe sepsis and refractory hypotension.
- Mainly gram- bacteria that release endotoxins,
- Staphylococcus aureus and streptococcus pyogenes that can produce toxic shock syndrome toxin.
Why does a patient become hypotensive during septic shock?
With a systemic response, all blood vessels dilute which causes the blood pressure to drop.
Instead of assisting in fighting the infection, the body’s response to sepsis actually slows down the blood flow, whcih makes our immune system less effective.
The bacteria can damage vital organs, and a lack of blood flow can result in organ failure.
What are the local signs of infection (4)?
Local signs of infection include:
1) signs of inflammation (redness, pain, heat, swelling)
2) presence of exudate or pus
3) lymphadenopathy (swollen + tender lymph nodes)
4) system-specific signs
- GI infections: vomiting, diarrhea
- Resp tract infections: sneezing, coughing, dyspnea
What are the systemic / general signs of infection (5)?
1) fever (or subnormal temperatures with some viral infections)
2) fatigue
3) headache
4) anorexia, nausea
5) malaise + myalgia (joint + muscle pain)
Which lab results are used to diagnose an infection in the body?
CBC
- increased WBC count
- blood lactate
- increased CRP
- increased segmented neutrophils
- increased band neutrophils
- increased monocytes
- increased basophils
- increased eosinophils
What does an increased blood lactate count indicate in terms of infection?
Increased blood lactate indicates an increased sign of sepsis in the body.
What does an increased level of CRP indicate in the body?
sign of general inflammation
what does an increased level of segmented neutrophils in the blood indicate in the body?
sign of bacterial infection
what does an increased level of band neutrophils in the blood indicate in the body?
sign of bacterial infection
what does an increased level of lymphocytes in the blood indicate in the body?
sign of viral + bacterial infection
what does an increased level of monocytes in the blood indicate in the body?
sign of recovery from severe infections
what does an increased level of basophils in the blood indicate in the body?
sign of parasitic infection
what does an increased level of eusinophils in the blood indicate in the body?
sign of parasitic infection
What is a neutrophil band shift to the left? What does it tell us about the patient?
A left shit indicates the presence of immature neutrophils in the blood.
An increase in immature band neutrophils typically means that the bone marrow has been signaled to release more WBCs and increase the production of WBCs.
This is an indication of a bacterial infection.
Identify the 4 sources of health-care associated infections.
Client flora
Invasive devices
medical personell
medical environment
What is a community acquired (CA) infection?
What is a hospital acquired infection?
CA infection is contracted less than 48 hours after hospital admission.
HA infection is contracted more than 48 hrs after admission, usually more virulent + resistant.
Identify the lab results for a patient with a viral infection
increased lymphocytes
Identify the lab results for a patient with a bacterial infection
increased segmented neutrophils
increased band neutrophils
increased lymphocytes
Identify the lab results for a patient with a parasitic infection
increased basophils
increased eusinophils
What is an anti-infective medication?
What are they further specified as?
Anti-infective medications are considered to be any medications that are effective against pathogens.
Further specified as:
- antibacterial
- antifungal
- antiviral