Unit 4 Exam Review Flashcards
Bacteremia that occurs when chewing food or brushing teeth
Transient
Bacteremia that is released into the bloodstream at a fairly consistent rate. Ex. Septic shock, endocarditis, early stages of typhoid fever, brucellosis, leptospirosis
Continuous
Bacteremia that infections demonstrate bacteria at variable times. This occurs in patients with un-drained abscesses. Bacteria may be released about 45 minutes before a febrile episode
Intermittent
Bloodstream infection that originates within the cardiovascular system
Intravascular
Bloodstream infection that enters the circulation through the lymphatics from another site of infection. Common portals of entry include the Genitourinary tract, respiratory tract, abscesses, surgical wound infections, and the biliary tract
Extravascular
Bacteria in the blood or the toxins produced by the bacteria causes harm to the host. Bacteria multiply more rapidly than immune system can work
Septicemia
Basic symptoms of septicemia
Fever or hypothermia, chills, hyperventilation, skin lesions, change in mental status, diarrhea
Serious symptoms of septicemia
shock or hypotension, disseminated intravascular coagulation (DIC), major organ failure, septic shock
What is used to clean the area for blood culture?
70% alcohol and another antiseptic (iodine)
How long should antiseptic stay on the skin when collecting a blood culture?
Follow manufacturer’s suggestions for recommended length of time
What type of broth is used in blood cultures?
Enrichment broth
How much bacterium is a blood culture designed to enhance?
Designed to enhance the growth of even one bacterium
What type of blood culture system do most labs use?
A dual system with an aerobic and anaerobic bottle.
What is the amount of blood needed for an adult blood culture? What is the minimum?
10-20 mL with a 10mL minimum
Why is so much blood needed for an adult blood culture?
Typically fewer bacteria per mL in adults in children
What is the amount of blood needed for a child’s blood culture?
1-5mL
Why is so little blood needed for a child’s blood culture?
More bacteria per mL may be adequate. Not safe to take large volumes of blood from children.
How many bottles are needed for a blood culture sample?
2 or 3 sets are sufficient. More may be necessary if patient is on antibiotics
How often are blood culture samples supposed to be collected?
spaced 1 to 2 hours apart.
Which is more important. The number of cultures or time interval they are collected?
Number of cultures
Which type of blood culture sample is more important to collect? The aerobic or anaerobic?
Aerobic. Recovery of anaerobic bacteria in blood is much more infrequent than recovery of aerobic bacteria
What needs to be done to blood culture bottles?
Provide proper incubation temp, constant agitation and continuous monitoring
What do blood culture bottles contain?
Nutrient broth, resins or charcoal and SPS
What system measures the production of CO2 produced by the metabolizing organisms by using fluorescence.
BACTEC
How do you know if bacteria is growing in a blood culture bottle?
Sensors on the bottom of each bottle increase in fluorescence as bacteria grows
What system measures CO2 and pH changes by a colormetric sensor located on the bottom of each bottle?
BacT/ALERT
How does a BacT/ALERT sensor work?
Sensor is separated from the broth by a membrane which is permeable to CO2. As the organism produces CO2, the sensor changes color
What do WBC give off in a blood culture?
CO2
What must be done to a positive blood culture?
A sample of the culture broth must be gram stained. A sample should also be plated onto conventional media which supports aerobic and anaerobic growth
Contaminate or Pathogen?
Growth of Bacillus, multiple organisms from several cultures, clinical presentation inconsistent with sepsis, infection at primary site of infection
Contaminant
Contaminant or Pathogen?
Growth of the same organism in repeat cultures, growth of certain organisms from endocarditis, growth of organisms such as enterbacteriaceae, growth of commensal organisms from immune-compromised patients
Pathogen
Possible pathogens with special requirements
HACEK Fungi Mycobacteria Brucella Mycoplasma Campylobacter
Inflammation of the tracheobronchial tree
Acute Bronchitis
Symptoms of acute bronchitis
cough, variable fever, and sputum production
What causes acute bronchitis
Viral agents and may be part of or proceeded by an URI (flu or common cold)
What can be a complication of acute bronchitis in infants and preschool aged children?
Bordetella pertussis should be considered
Excessive mucus production which leads to coughing up sputum on most days at least 3 months to two years.
Chronic bronchitis
What causes chronic bronchitis?
Bacteria may be the cause of acute flare-ups, but viruses are the more frequent cause
Inflammation of the lower respiratory tract involving the lung’s airways and supporting structures
Pneumonia
Associated pathogens are age-dependent
Ex. S. pneumonia, H. influenza, M. catarrhalis, M. pneumonia, C. pneumonia, Legionella
Community acquired bronchitis
Pathogens will include MRSA, P. aeruginosa, K. pneumonia, E. coli
Health care associated pneumonias (HCAP)
Infection caused by an organism infecting the lung and then gaining access to the pleural space via an abnormal passage
Pleural infections
Primary type of sample. Will be contaminated with upper respiratory secretions. Specimen should be the result of a deep cough
Expectorated Sputum
A respiratory therapist may need to assist patients and use postural drainage or thoracic percussion to stimulate production.
Induced Sputum
What type of reagent is used to induce sputum?
Aerosol induction. Breathe a 15% sodium chloride - 10% glycerin mix for 10 minutes
Invasive procedure which allows the physician to obtain bronchial washings or broncheoalveolar lavage samples; may also do bronchial brushings
Bronchoscopy
What might be performed if there is pleural fluid present in a Bronchoscopy?
Thoracentisis
Secondary Endotrachael and Transtracheal aspirates
What is the most common direct exam?
Gram stain
What is easy to recognize in a gram stain?
Bacteria and yeast
What are the requirements of a good sputum smear?
Fewer than 10 squamous epithelial cells per low power field.
What implies and excellent sputum specimen?
The presence of 25 or more WBC and a few epithelial cells
Presence of WBC is not necessary for acceptance of a specimen.
What can be examined for the presence of parasites and fungi
Wet prep
What can be used to identify acid-fast bacilli
Acid-fast stains
What may be used to detect Legionella?
Direct fluorescent antibody
What plates are used for differentiation of gram negative bacilli
Sheep blood and MacConkey
What plate is used for differentiation of Haemophilus and Neisseria?
Chocolate
What agar should be used if legionnaires disease is suspected?
BYCE Buffered charcoal yeast extract
What type of media is not used in specimens thought to contain contaminating oral flora
Enrichment media
What type of bacteria may require special procedures for detection?
Mycobacteria, Chlamydia, Nocardia, B. pertussis, Legionella, and Mycoplasma pneumonia
What type of URT Infection is usually caused by viruses?
Laryngitis
What type of URT Infection is caused by a virus which usually occurs in children under 3
Croup (Laryngotracheobronchitis)
Usually caused by H. influenza type b; Most common in children between 2 and 6; can be very dangerous because airway may be blocked
Epiglottitis
May accompany several viral infections. most bacterial infections are cause by S. pyogenes;
Pharyngitis
Usually caused by viruses; C. diphtheria may be isolated from patients with sore throat; massive immunization has reduced infection with Bordetella pertussis, but outbreaks still occur
Rhinitis
Inflammation of the mucous membranes of the oral cavity - caused by HSV
Stomatitis
Caused by Candida spp. usually occurs in young infants or immunocompromised patients
Thrush
What type of swabs are suitable for collecting most upper respiratory microorganisms
Cotton, Dacron or calcium alginated tipped swabs
What are transport requirements of swabs?
Remains moist - cultured within 4 hours.
Longer use a transport media
What types of swabs are better for recovering viruses, Neisseria and B. pertussis
Nasopharyngeal swabs
What organism are most throat cultures screened for?
S. pyogenes (group A)
What media is used to screen most throat cultures?
5% sheep blood agar