Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Micro240 > Cardiovascular > Flashcards

Cardiovascular Flashcards

1
Q

What are the three types of circulation

A

Pulmonary - Deoxy blood to lungs and oxygenated to heart

Systemic - Oxygenated blood away from the heart to the body and deoxy blood back to the heart

Coronary - circulation of the blood within the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

bacteremia

A

BLOOD IS STERILE

  • presence of living organism in the blood
    -isnt always a blood infection
    -can be dental work, injury, surgery
    -transient because immune system kills it
    -person can be asymp or have mild fever
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

pseudo- bactermia

A

false positive blood culture due to improper phlebotomy - no illness
-isolation of skin contaminants like CONs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Occult bactermia

A

-bacteria in blood of febrile child <2 who has no focus of infection and doesnt look ill
-S pneumo and H flu type used to cause but now with vaccines its not an issue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Transient vs intermittent vs continuous persistent bacteria

classification of bacteremia by duration

A

Transient - temporary , removed by the immune system

Intermittent -
Periodic seeding by same bacteria from an existing infection - cleared by immune system

Continous/ Persistent
-bacteria from intravacsular source that is released constantly into blood
-always present in blood
-due to heart valve infections, catheters,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Primary vs 2ndary vs bacteremia of unknown origin

classification on site of origin

A

primary - bacteria in vascular system due to infected cardiac valve or IV catheter

2ndary - bacteria from extravascular source -like lungs in pt with pneumonia

Bacteremia of unknown origin
-source if undefined
-very poor prognosis

Classification determines therapy and prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

classification of bacteremia by place of acquisition

A

Community acquired
from general community
S pneumo

Nosocomial bactermia
healthcare facility acquired
S. aureus, Enterococcus & Enterobacterales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

classification of bacteremia by type or # of org

A

Gram pos, neg, anaerobic or polymicrobial

mix is usually from GIT, burns or IV drug use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

SEPTICEMIA

A

presence & replication of organism in blood = infection of blood.
-bacterial invasion & toxin production evident.
-leads to systemic inflammatory response called Sepsis

Non-infectious inflammatory response  sepsis severe sepsis septic shock  death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Systemic inflammatory response syndrome (SIR)

A

-DR uses to categorize spectrum of increasingly severe inflammatory reactions from septicemia.

Fever, altered mental state, drop in systolic blood pressure, elevated resp/heart rate, high WBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

MOST COMMON ORGANISMS CAUSING SEPTICEMIA

A

Staphylococcus aureus
Escherichia coli
Streptococcus pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Extravascular septicemia:

A

infection in other body part or bacteria that disseminate as part of pathogenesis (Listeria, Salmonella)
-bacteria gets into blood via lymphatics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Intravascular septicemia:

A

Bacteria directly enters blood
-Intravascular Catheter = temporary ones in peripheral veins or semi permanent ones in central veins
-CoNS, S. aureus & Enterococcus most common gram pos.
-M. avium complex in HIV pos.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

INFECTIONS OF THE HEART

A

bacteria in blood can lead to
Myocarditis
Endocarditis
Pericarditis-infection of sac around heart (Pericardium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

INFECTIVE ENDOCARDITIS

A

-bacteria seeding heart valves forming a biofilm and infection
-valve damage and heart failure
-bacteria seeds blood causing continuous bacteremia with periodic febrile episodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Acute endocarditis:

INFECTIVE ENDOCARDITIS

A

-quick
-affects healthy heart
-caused by virulent bacteria like S. aureus, Enterococci, S. pneumo

HOWEVER S. lugdunensis or Corynebacterium jekeium caused progressive endocarditis in prosthetic heart valves or pace makers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Sub acute endocarditis

INFECTIVE ENDOCARDITIS

A

-slow progression
-affects hearts that are abnormal or already damaged
-caused by less virulent orgs NF or mouth like Viridans, bovis, mutans,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

LAB DIAGNOSIS OF BLOOD INFECTIONS

A

blood culture
-positive = critical = fatal outcome , contact physician and gram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When are BC collected

A

fever of unknown origin
-SID symptoms low blood pressure, raised heart & respiratory rate or shock with organ failure
-pt has severe invasive infection
-there is endocarditis

20
Q

OBTAINING A BLOOD CULTURE

A

-strict aseptic technique
-Label w patient info, date & time of draw
-Take before antibiotics & from veins- not arteries
-Don’t take from indwelling IV or intra-arterial lines
-draw below IV line
-Cleanse skin with 70%-95% ethanol followed by 2% chlorhexidine - leave on for at least 30sec let air dry
-BC bottles have SPS to inhibit Neisseria and P anaerobius
-Or put blood in tube with anticoagulants - don’t use EDTA, Na citrate or Heparin –can inhibit organism growth.

21
Q

BLOOD CULTURE VIALS

A

-O2& ANO2 BC bottles
-Nutritionally enriched have resins or charcoal to absorb toxins & antibiotics.
-SPS is the anticoag that inactivates antibiotics, neutralizes serum bactericidal activity & phagocytosis by immune cells

in ANO2 there is thioglycolate as O2 reducing agent & empty space in neck has gas mix that is not O2.

-drawn in sets -
1 SET = 1 O2 & 1 ANO2 vial - inoculate O2 first –to avoid contamination with air

22
Q

VOLUME OF BLOOD DRAWN FOR BLOOD CULTURES (BC)

A

volume of blood is most important to recovery
-bacterial effect of serum in blood has to be diluted by blood culture media
-1: or 1:10 ratio

Adults
10ml per bottle

Children - volume based on weight and special vial used

23
Q

HOW MANY SETS OF BC TO DRAW

A

Best is 3-4 sets in 24 hours
-but general practice is 2 sets in 24 hrs

-both sets can be done at the same time but they have to be from different spots or 1-2 hours from different venipuncture site

-if pt is negative after 2 sets in 48 hours keep taking sets or the organism can be viral - NO GROWTH IN BC

24
Q

SPECIAL CONSIDERATIONS FOR ENDOCARDITIS INVESTIGATION

is acute is suspected or is sub acute is suspected

A

BC should be taken during fever and before antibiotics
-immune system keeps bacteria levels low but fever will occur when the #s are high

If Acute endocarditis suspected:
Timing of draw is critical, take 2-3 sets of BC in a 30min time period

If sub acute endocarditis is suspected
-timing of draw less important instead focus on getting bacteria when it is increased in numbers in blood - INCREASE SAMPLE VOLUME
-3-5 sets spaced 30min to 1 hour apart in 24hrs

25
Q

CONTAMINATION OF BC BOTTLES

A

-False positive
-bacteria growing isnt what is actually in pts blood
-due to contamination from improper technique
-acceptable rate is 2%
-common contaminants are skin flora except in endocarditis
-if skin flora is reported the physician needs to decide if it should be treated

26
Q

CRITERIA TO DETERMINE CONTAMINATION OF BC VIALS
Identity of organism

A

S. aureus, Enterobacterales, GAS, S. pneumoniae, P. aeruginosa & C. albicans almost always a true septicemia

CoNS, Micrococcus, diphtheroids & P. acnes are contaminants EXCEPT in endocarditis

27
Q

CRITERIA TO DETERMINE CONTAMINATION OF BC VIALS
How many bottles is organism growing in

A

if same organism is in multiple bottles or set then it is a true infection doesnt matter if it is skin flora or not

can be endocarditis

28
Q

CRITERIA TO DETERMINE CONTAMINATION OF BC VIALS
Isolation of organism from blood + another sterile or non- sterile site.

A

person has a urine culture with the same organism – could mean a true septicemia

29
Q

AUTOMATED BC SYSTEM EXAMPLES

BacT ALERT

A
  • colorimetric change caused by shifts in pH from increased CO2 levels due to organism growth
30
Q

AUTOMATED BC SYSTEM EXAMPLES

BACTEC

A

Detects changes in fluorescence caused by shifts in pH from increased CO2 levels due to organism growth

31
Q

AUTOMATED BC SYSTEM EXAMPLES

Versa Trek

A

measures pressure changes caused by gas consumption or production due to organism growth

32
Q

What happens when Negative BC:

A

Preliminary report of No growth after 48 hrs sent on all bottles negative at this time.
Kept for 5 days before final report of No growth sent out

33
Q

What happens when positive BC:

A

in BSC L2 - broth removed and inoculated to slide for gram and to BA, CHOC, CNA, MAC, BRUC.
-do gram and issue preliminary
-phone physician with GRAM
-inform which bottles are positive (Aer or Anaero) and in how many sets after how many hours of incubation

34
Q

WORK UP OF POSITIVE BC

A

set up ID & AST
-Maldi for some organisms can be done right from the BC vial broth
-centrifuge to concentrate and lyse to remove protein in RBC (interferes with MALDI)
-molecular can be done from the broth as well
-phone and send reports to dr everyday
-BC are like CSF STAT

35
Q

CORYNEBACTERIUM JEIKEIUM

Less common ORGANISMS THAT CAUSE ENDOCARDITIS OR BACTEREMIA

A

Normal flora of skin, but MOST COMMON CAUSE of prosthetic joint, native valve endocarditis, sepsis, & meningitis
-nosocomial
-very virulent & multi drug resistant.
Vancomycin drug of choice

Strict aerobe, ppt/small NH, white
small pleomorphic gram pos bacilli
Cat pos
Urease neg
Sucrose - neg
-BC DO MALDI

36
Q

HACEK ORGANISMS

Less common ORGANISMS THAT CAUSE ENDOCARDITIS OR BACTEREMIA

A

fastidious, gnb that are slow-growing – may take > 5 days - like increased CO2 for growth

Haemophilus spp. including H. aphrophilus
Aggregatibacter
Cardiobacterium hominis
Eikenella corrodens
Kingella kingae

NF of mouth but can cause mouth infections
-cause native or prosthetic valve endocarditis
-cause subacute endocarditis
-if endocarditis is suspected and BC is negative then subculture the BC to CHOC and keep longer

37
Q

Capnocytophaga

Less common ORGANISMS THAT CAUSE ENDOCARDITIS OR BACTEREMIA

A

NF of mouth of human and animals

-peridontal disease
-risky for sick ppl and those who have spleen removed are at risk of septicemia & endocarditis.
-GNB slender with pointed ends (fusiform).
-Facultative but like CO2.
-Slow growing take 48-72hrs.
-Grows on BA/CHOC –sm colonies that look like film that spreads away from center of colony due to gliding motility
-Oxidase: positive

38
Q

Brucella Species

Less common ORGANISMS THAT CAUSE ENDOCARDITIS OR BACTEREMIA

A

-infectious (BSL3)-
-from eating unpasteurized dairy

Brucella abortus from cattle
Brucella suis from pigs
Brucella canis from dogs
Brucella melitensis from goat or sheep

CL2- BSC class II with PPE when working with specimen
-CL3 when working with colonies on culture plates. MOST COMMON LAB WORK ASSOCIATED INFECTION
-arthritis and spleen/liver enlargement
-can invade cells and cause septicemia, endocarditis and meningitis

39
Q

Brucella LAB TESTING

A

tests from colony must be CL3 –sent to PHL

-blood, tissues, fluids, bone marrow.
-Cultures incubated 21 days before negative report can be sent out.
-BA, CHOC & Brucella agar in 5-10%CO2.

  • BA: small, grey NH MAC: NG
    -Gram: gncb,
    -Oxidase & Urease: positive
  • ID to genus level.
  • use MALDI or PCR.
    -Serology
    Reported to MOH –potential bioterrorism agent.
    Treatment is combination of multiple antibiotics
40
Q

OTHER ORGANISMS TO CONSIDER IF BC IS POSITIVE BUT SUBCULTURE IS NG

Nutritionally variant Streptococci

A

Abiotrophia & Granulicatella

-Oral NF but can cause endocarditis & septicemia.
-needs pyridoxal (vitamin B6) to grow
-Can add to BA ingredients or as a disk or a staph streak.
-satellite around Staph as NH or AH colonies
-grows in BC vials because human blood has vitamin B6.
-Gram: pleomorphic cocci both in pairs & chains that may look bacillary

41
Q

OTHER ORGANISMS TO CONSIDER IF BC IS POSITIVE BUT SUBCULTURE IS NG

Campylobacter spp. :

A

-gastroenteritis, from eating undercooked meat or animal products
-can be missed in BC because it only grows on CHOC or CAMPY because it like a microaerophilic conditions 42C for 48 hours

-hard to see on gram
-use fuchcin counterstain
-acridine orange fluorescent stain

-small curved GNB - gull wings

42
Q

OTHER ORGANISMS TO CONSIDER IF BC IS POSITIVE BUT SUBCULTURE IS NG

Mycobacteria (BSL3):

A

-BC media needs enrichment like LJ or Middlebrook base
- 6-8 wks. to grow.
-Mycolic acid won’t stain with gram –use ZN, kinyoun or Auramine Rhodamine.

43
Q

OTHER ORGANISMS TO CONSIDER IF BC IS POSITIVE BUT SUBCULTURE IS NG

Coxiella burnetii (BSL3):

A

-Zoonotic, from cows or goats- highly infectious, transmitted by inhalation or rarely by eating raw animal products.
-<5% of those infected especially those with valve defects or vascular grafts will get endocarditis – called Q fever

-Gnb, fastidious, obligate intracellular pathogen, won’t grow on routine media.

-Must use serology to diagnose endocarditis.

44
Q

Fungemia

A

Fungal growth in blood

C albicans - most common
-yeast is quick to grow in vials
-dimorphs grow in vials but they take longer and can be missed after the 5 day incubation check
-if youre investigating a slow grower sub negative BC vials to fungal plates & keep up to 4 weeks

45
Q

Viremia:

A

Presence of virus in blood

BC are negative
Diagnosed by serology or molecular testing

46
Q
A

Micro240 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions