Intro Flashcards
WBC tend to be ____ in the presence of an infection
elevated
What are the relative proportions of the WBC
- Neutrophils (roughly 60 – 70%)
- Lymphocytes (roughly 20 – 30%)
- Monocytes (approximately 1 – 6%)
- Eosinophils (approximately 1 – 3%)
- Basophils (less than 1%)
____ are the most abundant WBC and act in defense in bacterial and fungal infections as well in times of physiologic stress
neutrophil
_____ Primary defense for viral infections
Elevations also in leukemias and lymphomas
Lymphocytes
_____ are the most common WBC in the lymph
lymphocytes
_____ are the largest WBC, becomes macrophages and are elevating in late or chronic infections
monocytes
____ defense mechanism in allergic reactions and parasitic infections
Eosinophils
_____ defense in hypersensitivity reactions and release inflammatory mediators
basophils
What does cloudy/turbid urine indicate?
pyuria (pus or WBC present in the urine)
What does an elevated leukocyte esterase in a urine dipstick analysis indicate?
increased WBC in urine, aka infection
Nitrites are produced by _____ bacteria
gram - bacteria
Wet prep is best to show ___ and _____
Clue cells (Bacterial Vaginosis)
Protozoans (Trichomonas)
looking for bacteria
KOH prep is best to show ___ cells
fungal cells
What will a clue cell look like under a microscope?
clue cells are epithelial cells of the vagina that get their distinctive stippled appearance by being covered with bacteria.
______ is used when collecting fluid in which opening pressure is needed
Lateral decubitus
_____ can be used if opening pressure isn’t needed
Upright position
How many tubes do you collect in a CSF? What goes in each?
- Cell Count and differential
- Glucose and protein levels
- Gram stain, C&S
- Other
What does increased CSF pressure indicate? decreased?
Increased pressure:
Infection, Tumors, Intracranial bleed
Decreased pressure:
Dehydration, CSF Leakage
What does cloudy/turbed CSF fluid indicate?
infection
What does xanthrochromia CSF fluid indicate?
bleeding
What is the normal viscosity for CSF fluid? What does thick mean?
same as water
infection or malignancy
What does decreased glucose in the CSF mean?
infection
What is normal for proteins and CSF?
normal is NONE to trace proteins
elevated proteins means infection, malignancy or autoimmune disease
What three additional CSF tests will be elevated in a bacterial infection?
lactic acid
lactate dehydrogenase
c-reactive protein
What are 3 contraindications for a lumbar puncture?
When would you order a brain CT before a lumbar puncture?
coma without cause
seizure
focal neurologic signs
immunosuppression
When would you order a brain MRI before a lumbar puncture?
Looking at normal pleural fluid under a microscope, what would you expect to find?
normal pleural fluid has small numbers of WBCs with no RBCs or microorganisms.
What is transudate?
An imbalance between the pressure within blood vessels (which drives fluid out) and the amount of protein in blood (which keeps fluid in), resulting in an abnormal accumulation of fluid. (talking about pleural fluid)
What is exudate caused by?
Caused by injury or inflammation of the pleura resulting in pleural effusion.
____ and ____ are the two most frequent causes of transudate
CHF or cirrhosis
What 3 things are normal to find in transudate?
clear fluid
low protein/albumin/LDH
cell count = few
What are some etiologies of exudate?
infectious diseases, bleeding, inflammatory conditions, malignancies, others
What 3 things are normal to find in exudate?
fluid may appear cloudy
high protein/albumin/LDH
cell count is increased
What does Light’s criteria signify? What are the 3 things?
Assists in the classification of pleural fluid being transudative or exudative
According to Light’s criteria, pleural effusion is likely exudative if at least one of the following exists
Pleural fluid protein:serum protein ratio >0.5
Pleural fluid LDH:serum LDH ratio >0.6
Pleural fluid LDH is >0.6 or >⅔ times the normal upper limit for serum LDH
What does having a milky appearance to pleural fluid indicate?
to lymphatic system involvement
Name some things you can test pleural fluid for
Glucose—typically about the same as blood glucose – ↓ in infection and if additional ↓ pH = malignancy
Lactate levels can ↑ with infectious pleuritis
Amylase levels ↑ with pancreatitis, esophageal rupture, or malignancy.
TG levels ↑ with lymphatic system involvement.
Tumor markers ↑ with some cancers
What are some complications of pericardiocentesis?
Myocardial perforation
Bleeding
Pneumothorax
Arrhythmia
Acute pulmonary edema
What is the water bottle sign?
What is a paracentesis used for?
Used to help diagnose the cause of peritonitis or ascites (peritoneal fluid accumulation)
What does milk-coloured (chylous) paracentesis fluid indicate?
malignant tumor, lymphoma, TB, parasitic infection, hepatic cirrhosis
What does cloudy/turbid paracentesis fluid indicate?
peritonitis, primary bacterial infection, perforated bowel, appendicitis, pancreatitis, strangulated or infarcted bowel
What does string-like viscosity of joint fluid indicate?
normal
What does increased viscosity of joint fluid indicate?
septic arthritis
What does decreased viscosity of joint fluid indicate?
inflammation
A chest x-ray is used to screen the lungs for ????
Consolidation
Infiltrates
Cavitations
Nodules
Effusions
_____ utilize radiation to produce images. Better for (bone/soft tissue)
CT Scan (computed tomography
bone
_____ uses powerful magnetic fields and radio frequency pulses to produce images. Better for (bone/soft tissue)
MRI
soft tissue
_____ retains the dye in a gram stain
peptidoglycan
What is the process for a grain stain? short version at the end
Slide is stained with crystal violet dye - turning all cells purple
Gram’s iodine solution - causes dye to adhere more strongly to cell wall
Decolorization with ethyl alcohol and acetone
G+ cells - thick cell walls which retain the dye = stay purple
G- cells - thin cell walls, decolorizer easily penetrates and washes away dye
purple dye is applied
iodine is applied
alcohol wash
the counterstain, safranin is applied Gram + cells stay purple and gram - cells are pinkish red
Name the gram + cocci clusters
Name the gram + cocci chains
Name the gram + rods
Name the gram - cocci
name some gram - rods
Name some reasons your culture could be negative even if the patient does have an infection
Pathogen may not be present in sufficient quantity in the sample collected to be detected
Symptoms could be due to a viral infection
Patient could have been on previous antibiotics
When ordering blood cultures, what is the protocol?
Typically order TWO or more samples from TWO locations
How do you interpret blood culture results?
If both are positive for same organism = POSITIVE Culture
If one is (+) and one is (-) = possible contamination; may require re-testing
If both are negative for microorganisms (Reported as NO GROWTH) = NEGATIVE Culture
____ is the most common pathogen on a urine culture
E. coli
What is considered a positive urine culture?
Positive culture is ≥ 100,000 colonies of a single bacteria
What does a rust colored sputum culture indicate?
strep pneu
What does a yellowish/green sputum culture indicate?
H. influenzae
What does a green sputum culture indicate?
pseudomonas
What does a red, currant jelly sputum culture indicate?
klebsiella
What does a bloody sputum culture indicate?
tuberculosis
What does a foul smelling sputum culture indicate?
anaerobes
What does a thin/scant sticky sputum culture indicate?
atypicals
________, ______ and _____ do not grow on a basic sputum culture media
Atypical bacteria, mycobacterium (TB), and fungal infections
What is the Centor criteria?
What is MIC?
Minimum Inhibitory Concentration (MIC)
the lowest concentration of drug that inhibits the growth of the organism
For sensitivity testing, you want the bacteria to be _____ to the abx in question at a (low/high) number
Susceptibility at the lowest MIC, (S with low number next to it)
