diagnostic & therapeutic techniques Flashcards
general symptoms of infection
fatigue, fever, chills
symptoms of skin/wound infection
redness, swelling, discharge, tenderness
lower rsp tract infection symptoms
productive cough, SOB, pleuritic chest pain
upper rsp tract infection symptoms
congestion, discharge/drainage, HA/pain/pressure
GI infection symptoms
abd pain, N/V/D
genitourinary infection symptoms
pain/burning while urinating, vaginal/urethral discharge
neuro infection symptoms
HA, confusion, altered mental status
MSK infection symptoms
joint pain, swelling, redness, warmth
WBC is typically elevated in the presence of ?
infection
leukocytosis
what are 5 types measured in differential WBC
- neutrophil
- lymphocyte
- monocyte
- eosinophil
- basophil
what WBC are granulocytes and what are agranulocytes
granulocyte - neutrophil, eosinophil, basophil
agranulocyte - lymphocyte, monocyte
what is the most abundant and least abundant WBC
most - neutrophil
least - basophil
“Never Let Monkeys Eat Bananas”
what is the primary defense in bacterial infections and first to arrive at site of infection
neutrophil
also active in fungal infections and physiologic stress
when bone marrow is signaled to make more neutrophils due to presence of infection
immature neutrophils (bands)
“left shift”
primary defense for viral infections
lymphocytes
“clean up” cells
what is the most common WBC in lymph
lymphocytes
what is the largest WBC and is elevated in late/chronic infection
monocytes
can migrate into tissue/organs and become macrophages
what WBC is seen in allergic reactions and parasitic infections
eosinophils
what is seen in hypersensitivity reactions and releases inflammatory mediators
basophils
for a “clean catch,” collect the urine sample when urine has only been in the bladder for ?
2-3h
urinalysis symptoms of a UTI
color - cloud/turbid - has pyuria
odor - strong/fishy odor
chemical dipstick - leukocyte esterase, nitrites, blood
microscopic examination - WBC, RBC, microorganisms, casts
leukocyte esterase in a dipstick analysis shows
enzymes made by WBC
increased WBC in urine
nitrites are produced by ___ in a dipstick analysis
g-
blood in a dipstick analysis suggests ?
infection/inflammation/injury in urinary tract
RBC present in a dipstick analysis is indicative of
infection/inflammation/injury
Casts in dipstick analysis is indicative of
kidney infection
wet prep/KOH prep is indicated for
vaginal/cervical/urethral discharge
difference between wet and KOH prep
wet
- specimen placed on slide with saline solution
- clue cells (BV), protozoans (trichomonas)
KOH
- with KOH
- fungal cells
epithelial cells of the vagina that get their distinctive stippled appearance by being covered with bacteria
clue cells
difference between lateral decubitis vs upright positions during LP positioning
lateral decubitis - opening pressure is needed
upright - opening pressure isn’t needed
normal physical/lab characteristics of CSF
clear and colorless
almost same viscosity of water
No RBC
< 5 WBC present
glucose - 50 - 75 mg/dL
No protein
increased pressure of CSF is indicative of
infection, tumor, intracranial bleed
decreased pressure of CSF is indicative of
dehydration, CSF leakage
cloudy/turbid CSF color is indicative of
infection
xanthochromia in CSF is indicative of
bleeding
thick CSF is indicative of
infection or malignancy
what is the main complication from lumbar punctures
headache*
normal pleural fluid has ____ number of WBC with ___ RBC or microorganisms
small
no
RBC present in pleural fluid analysis is indicative of
trauma or malignancy
imbalance between pressure within blood vessels and the amount of protein in blood
transudate
fluid caused by injury or inflammation of the pleura resulting in pleural effusion
exudate
2 pleural fluid analysis
- microscopic exam
- total cell counts
- cytology - infectious disease test
- gram stain
- bacterial C&S
- individualized testing
milky pleural fluid is indicative of
lymphatic system involvement
reddish pleural fluid may indicate presence of
blood
cloudy, thick pleural fluid may indicate
presence of microorganisms and/or WBC
chemical tests for pleural fluid analysis
- glucose - decrease in infection, additional decrease pH in malignancy
- lactate levels - increase with infectious pleuritis
- amylase - increase in pancreatitis, esophageal rupture, malignancy
- TG levels - increase with lymphatic system
- tumor markers - increase
what is used to help diagnose the cause of peritonitis or ascites (peritoneal fluid accumulation)
paracentesis
causes:
- new onset ascites
- large or refractory ascites
- suspected spontaneous or secondary bacterial peritonitis
what is used to diagnose the cause of joint effusions? s/s?
arthrocentesis
s/s: joint pain, joint swelling, erythema, warmth
obtain chest x-ray when there are s/s of pulmonary infection:
- dyspnea, SOB
- cough
- fever, chills
- pleuritic chest pain
used to screen pulmonary infection, masses, trauma and other pathologies
CXR
uses radiation to produce images
CT scan
uses powerful magnetic fields and radio frequency pulses to produce images
MRI
cells stained purple are
G+ cells
thick cell walls
cells stained blue are
G- cells
thin cell wall
cell turns pinkish red with safranin red is
g-
cell is purple with safranin red is
g+
G+ staphylococcus
s. aureus
s. epidermidis
G+ streptococci a-hemolytic
- s. pneumonaie
- s. viridans
G+ streptococci B-hemolytic
- S. pyogenes
- S. agalactiae
- s. Bovis
G+ steptococci y-hemolytic
s. enterococcus
g+ rods
- corynebacterium
- c. diphtheriae - clostridium
- c. difficiles - bacillus
- b. anthracis
- b. cereus - lactobacillus
- l. acidophilus - listeria
- l. monocytogenes
G- cocci (3)
- acinetobacter
- moraxella
- m. cat - neisseria
- n. gonorrhea
- n. meningitidis
g- rods (16)
- bacteroides - B. fragilis
- campylobacter
- enterobacter
- escherichia - E. coli
- klebsiella
- proteus
- helicobacter - H. pylori
- pseudomonas
- salmonella
- serratia
- shigella
- vibrio - V. cholera
- yersinia - Y. pestis
- haemophilus - H. flu
- legionella - L. pneumonphila
- bordetella - B. pertussis
why is gram stain important in clinical medicine
- aids in selection of culture media
- initial selection of abx
- establish preliminary dx
if a culture is negative for bacteria, it does not rule out an infection bc:
- pathogen may not be present in large quantities
- symptoms could be due to a viral infection
- pt could have been on previous abx
for blood cultures are ordered ___ or more samples from ___ locations
two, two
stool culture labs evaluate for most common intestinal ____ pathogens
bacterial
to test for parasites, you must order:
stool for ova and parasites
a urine culture is positive when ?
+100k colonies of a single bacteria
men and some cath specimens = 1k>
rust colored sputum is caused by what organism
s. pneumoniae
yellowish/green sputum is caused by what organism
H. flu
green sputum is caused by what organism
pseudomonas
red, currant-jelly sputum is caused by what organism
klebsiella
bloody sputum is caused by what organism
tuberculosis
foul-smelling/bad tasting sputum is caused by what organism
anerobe
thin/scant sticky sputum is caused by what organism
atypicals - mycoplasma pneumoniae, c. pneumonaie
used to determine whether a person with pharyngitis has a group A streptococcal infection
rapid strep test
when do you perform a throat culture
when a strep test is negative
avoid strep throat testing in children how old
< 3
avoid routine rapid strep testing of what type of pt
asx
children <3y/o
4 criteria for throat culture
- hx of fever
- tonsillar exudate
- tender anterior cervical adenopathy
- absence of cough
<15y/o +1
>44y/o -1
negative throat culture is a sore throat caused by ?
viral infection
most common cause of viral sore throat
adenovirus
sensitivity testing is not necessary when…
most common pathogens are known and are known to be susceptible to first line tx
when is sensitivity testing indicated (4)
- pathogens are unknown or mixed pathogens
- known resistance
- severe infection
- infection is not responding to typical first line tx
what are the 4 CSF tubes
- WBC w/diff
- glucose and protein
- gram stain, C&S
- other - ordered if initial tests are abnormal
- lactic acids
- lactate dehydrogenase (LDH)
- C-reactive protein
- (all will increase if infection present)
clear fluid
low protein/albumin/LDH
few cell count
what type of fluid?
transudate
fluid can appear cloudy
high protein/albumin/LDH
increased cell count
what type of fluid?
exudate
according to Light’s criteria, pleural effusion is likely exudative if at least one of the following exists:
- pleural fluid protein:serum protein ratio >5.0
- pleural fluid LDH:serum LDH ratio >0.6
- pleural fluid LDH is >0.6 or >2/3 times the normal upper limit for serum LDH
increased viscosity from an arthrocentesis is indicative of ? decreased viscosity?
increased = sepsis
decreased = inflammation
string-like = normal
lobar consolidation is usually seen in ? while patchy nodular infiltrates is usually seen in ?
pneumonia
pulmonary edema (CHF)
process of gram stain illustration
- stain with crystal violet dye
- grams iodine solution (causes dye to stick more onto cell wall)
- decolorize with alcohol and acetone
- counterstain with safranin red
what is the most common pathogen in urine cx
e. coli
when do you order a sputum cx?
when you suspect a bacterial infection in the lungs (pneumonia)
may be ordered after tx of an infection to see effectiveness
what are the most common bacterial pathogens in sputum cx
- strep
- staph
- haemophilus
- klebsiella
lowest concentration of drug that inhibits the growth of the organism
minimum inhibitory concentration (MIC)
what is the zone of inhibition
abxx is effective against the bacteria, leaving a clear ring
how long does sensitivity testing take?
24-48 h AFTER organisms have been identified on culture
how are sensitivity tests reported?
susceptible
intermediate
resistant
