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125 Cards in this Set
- Front
- Back
Symptom (defined by stedmans medical dictionary)
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Any morbid phenomonon or departure from the normal in function, appearance, or sensation, experienced by the patient and indicative of disease
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Sign
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any abnormality indicative of disease discoverable by the physician (PA) at his or her exam of the patient.
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Symptom (generic definition)
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indicator of disease as interpreted by the patient
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Sign (generic definition)
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objective finding of the examiner
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Complication
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morbid process or event occuring during a disease which is not an essential part of the the disease, although it may result from it or from dependent causes
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Surgeons
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-concerned with the technical aspects of performing procedures
-perform minimally invasice procedures -use real time imaging to guide procedures -utilize lasers to cut and obliterate tissues -trasplant organs |
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Internists
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-perform highly specialized invasive procedures
-stent occulded vessels -perform gi and pulmonary endoscopy -transplant cells/tissue -deal with end-of-life treatment |
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Current medical specialties
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family medicine
internal medicine general surgery ob/gyn peds ER psychiatry |
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Aspects of Prevention
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-dietary restraint;moderation of calories; low Na, saturated fats, trans fatty acids, and simple CHO
-regular strenuous exercise and strengh training -maintain adequate bone density -avoid risky behavior (drugs, tabacco, EtOH) -dental hygeine -quality sleep -minimize stress -regular physicals and surveillance for common diseases |
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Regular Health Monitoring should include:
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-routine blood and urine screens
-fecal occult blood -breast exam and mammogram -digital rectal exam + PSA |
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medical conditions in pregnancy
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-gestational diabetes
-DVT -cholelithiasis/pancreatitis -eclampsia/hypertension -hyperthyroidism -HIV |
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How we get sick
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-trauma
-heredity -infection -autoimmune disease -malignancy -aging/degeneration -bahvior/environment -pregnancy |
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Diseases that have no defineable single cause are likely due to...
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a combination of:
-genetics (multiple alleles with incomplete penetrance), - environment (and behavior) - infection (active, latent, or past) - bodies overall response eg. artherosclerosis |
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how immune system normally functions
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Normally, thymus removes lymphocytes that are capable of attacking normal cells
normally, bone marrow removes B cells that are self reactive |
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Immune attack may be triggered by...
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-alterations to cell surface antigens by viral infection
-deposition of foreign protein -antigen-antibody complex deposition -lack of immune suppressor cells (supressor T cells) |
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Environmental factors c autoimmune diseases
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tissue damage from infection, toxic exposure causes activation of monocytes
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molecular mimicry
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infectious organisms express antigens similar to self-antigens
eg. rheumatic fever, beta-hemolytic streptococcus infection |
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Discovery of xray
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1895
Wilhelm Konrad Roentgen passed current through cathode ray tube widespread use by 1913 |
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introduction of CT scan
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1971
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introduction of MRI
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1980
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Introduction of US
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first in 1940s
accredited medical purposes 1950s |
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Non ionizing radiation modalities
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ultrasound
MRI |
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Ionizaing radiation modalities
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conventional radiographs
fluoroscopy CT scans nuclear imaging modalities |
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RAD
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Radiation absorption dose
amount of radiation your body was exposed to |
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REM
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Radiation effect in man
amount of biological damage recieved from the exposed radiation |
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lethal dose of radiation exposure
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5000 RADS
(kills 50% of humans) |
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High doses of radiation cause..
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hematologic effects
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Prolonged repeated exposure to radiation causes...
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accelerated induction of malignant disease
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Lifetime permissable dose of radiation
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RADS = 5 x (age -18)
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Health care workers permissable exposure to radiation
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whole body/gonads/eye lens: 5 RADs/year (5000 mrads)
hands/forearms/feet: 75 RADs/year |
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how an xray is generated
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-an anode (tungsten or molybdenum) is bombarded with electrons from a cathode
- xrays pass through pt and expose the film |
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use of fluorescent sheets in xrays
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-fluorescent sheets glow after xray to lengthen exposure (bc xrays require long exposure for film development).
-reduces length of exposure to xrays for pt |
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Radiolucent
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xrays pass through
picture is dark |
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radiopaque
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xrays bounce off (dont pass through)
picture is light |
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radiographic appearance is determined by:
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atomic number
thickness overlap of structures objects shape distance from film object density |
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radiographic densities
(darkest to lightest) |
air - darkest
fat soft tissue (muscle)/ fluid bone non-physiologic density - lightest |
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radiographic density is...
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sum of all densities and thickness interposed between the xray beam source and the film
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the greater the difference in adjacent densities....
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the sharper the border
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when similar densities are in the same plane...
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borders become indistinct and blend together into 1 common density
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overpenetrated xray
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over exposed
radiographs are too dark too many RADs |
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radiographic projections describe...
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path of the xray beam
eg. AP, PA, lateral, oblique |
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object is clearest when it is..
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up against the film (or as close to the film as possible)
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CT
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computerized tomography
uses ionizing radiaiton (like xray) rapid scanning axial plane ONLY visualizes bone better than soft tissue |
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Fluoroscopy
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real time visualization
continuous xray beam |
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fluoroscopy uses
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venous and angiographic procedures
fracture reduction |
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Diagnostic ultrasound
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-non ionizing radiation
-sound waves generated and reflected back (sends and catches sound waves) -frequency is >15,000 cycles |
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advantages of US
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easy to use
noninavasive portable can insert into every orifice |
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disadvantage of US
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bone and air filled structures interfere with image
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indications for US
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gall bladder disease
arterial and venous pathology ob/gyn diagnostics neonatal |
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MRI
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-pt placed at core of large magnet
-radiowaves passed through body in a particular sequence of very short pulses -waves knock hydrogen atoms (in fat and water) out of alignment -hydrogen atoms eventually re-establish the previous equilibrium/alignment with the surrounding magnet -causes absorbed radiowaves to be emitted -SO each pulse causes a responsing pulse of radio waves to be emitted from the patients tissue -location from which the signals have originated is recorded by a detector and sent to a computer |
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relaxation time on MRI
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-time required by H+ atom to regain equilibrium state (get back into alignment in the magnetic field)
-has an initial energy when it is knocked into a higher orbit and another energy when it comes back down to original orbit |
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2 relaxation times
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T1- time to recovery
longitudinal relaxation time T2 - time to relaxation transverse relaxation time |
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T1
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-time to recovery
-longitudinal relaxation time -fat appears white -air cortical bone, CSF appears dark |
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T2
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time to relaxation
transverse relaxation time blood, CSF appears white |
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MRI can visualize
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-gray matter vs white matter
-better for visualizing soft tissues -different views (not just axial view like CT scan) |
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advantages of MRI
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-utilizes non-ionizing radiation
-can scan in multiple planes -can scan in 1 mm to several cm increments -better soft tissue detail -noninvasive evaulation of cerebral blood vessels (MRA angiogram) |
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disadvantages of MRI
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-poor bone detail
-longer scanning time than CT (~1 hr per body part) -cant be scanned with certain kinds of metal implants -poor quality of images of abdomen and chest due to breathing and peristalsis (takes slow pics so anything moving results in poor quality pics) |
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radioisotope scanning
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-visualize living organs and tissues (measures physiology)
-attach radioactive tracer to something that is taken up into the cells -isotope emits gamma rays for breif period of time -ray are recorded by gamma camera |
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radioisotope scanning can identify:
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bone cancer
occult fx pulmonary emboli thyroid cancer cardiac ischemia kidney not working |
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technetium-99m
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-most useful tracer
-inexpensive -short half-live (so doesn't expose to as much radiation) -readily available from portable generator -high concentrations of isotope will congregate in tissues with inc metabolism -gives less precise anatomic information |
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technetium 99m pertechnetate
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trapped by thyroid
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technetium 99m macroaggregated albumin
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trapped by thyroid gland
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technetium 99m methylene diphosphonate
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trapped by bone tissue
used for bone scan |
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thallium 201
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used for evaluation of myocardial blood flow
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iodine 131
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for thyroid imaging
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cardiac thallium scan
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used to eval heart
can do in real time to see movement of heart |
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iodine contrast
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-water soluble
-can be given IC, IA, intrathecal, endobronchial, directly to GI -risk for allergic rxn -can cause renal failure -contraindicated in renal insufficiency |
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barium contrast
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-water insoluble
-given po or rectally -good for GI tract imaging -very irritating if GI tract is perforated -risk of fecal impaction, aspiration, perforation |
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gastrograffin contrast
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-water soluble
-iodine based contrast -good for GI tract imaging, but not as good as barium - used if GI tract perforation is suspected -promotes peristalisis -may cause serious lung edema in cases of esphageal-trachea fistulas |
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gadolinium
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-rare earth, metallic, paramagnetic contrast
-used only for MRI enhancement -no risk of allergic rxn -nontoxic to kidneys |
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microbial entry sites
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respiratory, GI, GU, skin, conjunctiva
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Microbial adherence
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anchorage to tissue or tissue matrix
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growth after entry depedns on...
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temp, pO2, pH, nutrients,
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Colonization
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present but no an infection
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Nasocomion infections
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infections aquired during the process of getting treatment for other problems (usually hospital acquired infections)
2,000,000 pts 88,000 deaths $4.5 billion |
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Common nasocomial infections
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UTI
pneumonia surgical wound infection vascular access infection clostridium Difficile colitis |
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UTI
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Urinary tract infection
often due to foley catheter |
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What is most important factor that correlates the incidence of infection in a pt with an indwelling urinary catheter?
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amt of time catheter is in
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biofilm
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-collection of microorganisms surrounded by the slime they secrete
-99% of all bacteria live in biofilm communities -interfere with antiobiotic efficiency and enhance accumulation of bacteria |
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Hospital aquired pneumonia
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-host unable to clear bronchial secretions
-unable to sustain immune response to bacteria in lung tissue -microbes often more virulent and resistant to standard bacteria |
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Hospital aquired pneumonia is common in...
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mechanical ventilator pts (bacteria forms a biofom around the endotracheal or traceostomy tubes)
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Vascular access infection
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due to infected ports from IV sites
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Risks of infections IV site infections
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endocarditis
staph on aortic valve pulmonary abcess |
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Surgical wound infection
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-contamination with bacteria during procedure
-skin or viscera -foreign body (suture material) -poor surgical technique -malnutrition |
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Factors the predipose to postoperative infections
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-malnutrition
-compromised immune sys (HIV, elderly, diabetes, malignancy, chemo) -impaired vascular supply (vascular dz, radiation therapy can damage microvasculature) |
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initiating events for Clostridium Difficile pathogenesis
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-exposure to antibiotics - usually broad spectrum (inhibits normal intestinal bacterial flora so C.Diff can now colonize it)
-established susceptabiility to infection |
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Drug resistant bacteria
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1. methicillin-resistant staphylococcus aureus (MRSA)
2. vancomycin resistant enterococcus (VRE) 3. fluoroquinolone resistant gram negatives |
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How do most antibiotics work?
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-inhibition of cell wall synthesis
-inhibition of protain synthesis -inhibition of DNA synthesis/transciption |
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Antibiotics that work by inhibition of cell wall synthesis
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penicillin
vancomycin cephalosporins |
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Antibiotics that work by inhibition of protien synthesis
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macrolides
tetracycline aminoglycosides |
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antiobiotics that work by inhibtion of DNA synthesis/transciption
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quinolones (inhibits DNA gyrase)
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Mechanism of antiobiotic resistace for MRSA
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-methicillin resistant staph aureus
-bacteria produce beta lactamase (gram neds already produced it, gram pos learned to synthesize it d/t transfer of DNA instructions from other bacteria -production of beta lactamase by bacteria destroys antibiotic, so beta lactames (of the antibiotics) are ineffective in inhibiting cell wall synthesis |
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Mechanism of antibiotic resistance for VRE
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-appeared in 1988
-alteration of cell wall peptide - so no longer allows vancomycin to interferes with cell wall synthesis -DNA instructions for new cell wall found in plasmids |
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Mechanism of antibiotic resistance for fluoroquinolone resistane gram negatived
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-widespread use of antibiotic
-mutation of DNA gyrase so no longer effective -some bacteria developed ability to expel drug from bacterial cytoplasm -most likely due to mutation of bacteial DNA |
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Roles of animals in spread of resistance
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-farmers use cipro in food/drink of chicken and turkeys to make the animals bigger
-so common resevoir for antibiotic resistance |
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Children are common resevoirs for what resistance?
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MRSA
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Mechanisms to overcome bacterial resistance
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-follow hygienic practices
-synthesis of agents with improved antimicrobial activity -antibiotic control programs -prescribe judiciously -pharm industry should be more limtied in promotion of antibiotic use |
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Etiologic Factors
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-causes of disease
-includes biologic agents (bacteria, viruses), physical forces (trauma, burns, radiation), chemical agents (poisons, alcohol), nutritional deficits/excesses |
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risk factors
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factors that predispose to a particular disease
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Pathogenesis
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-sequence of cellular and tissue events that take place from the time of intial contact with an etiologic agent until the ultimate expression of the disease
-how the disease process evolves |
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Etiology
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what sets the disease process in motion
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morphology
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fundamental structure or form of cells or tissues
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Histology
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study of cells and extracellular matrix of body tissues
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epidemiology
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-study of disease in populations
-used to study spread of disease, risk factors for multifactorial diseases -looks at patterns such as race, ditery habits, age, lifestyle, geographic location etc |
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incidence
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number of new cases arising in a population during a specified time
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prevalence
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number of people in a population who have a particular disease at a given point in time
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Motality
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death
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Morbidity
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effects an illness has on a person's life
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syndrome
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compilation of signs and symptoms that are characterisitc of a specified disease state
eg chronic fatigue syndrome |
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sequelae
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lesions or impairments that follow or are caused by disease
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diagnosis
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designation as to the nature or cause of a health problem
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reliability
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extent to which an observation, if repeated, gives the same result
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validity
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extent to which a measurement tool measures what it is intended to measure
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Sensitivity
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proportion of people with a disease who are positive for that disease on a given test
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Specificity
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proportion of people without a disease who are negative for that diseasee on a given test
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positive predictive value
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refers to proportion of true-postives that occur in a given population
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negative predictive value
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true-negatives that occur in a given population
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preclinical stage
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not clinically evident but destined to progress to the clinical disease
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subclinical disease
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not clinically apparent and not destined to become clincally apparent
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Clinical disease
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manifested by signs and symptoms
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natural history
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progession and projected outcome of a disease without medical intervention
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prognosis
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probable outcome and prospect of recovery from a disease
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primary prevention
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keeping disease from occuring by removing all risk factors
eg. immunizations |
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secondary prevention
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early detection so disease is still asymptomatic and treatment measure can affect a cure
eg pap smear for early detection of cervical CA |
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tertiary prevention
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clinical interventions that prevent further deterioration or reduce complications of disease once it had been diagnosed
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