Brainscape's Knowledge GenomeTM

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


See full index

Year 2 PBL > U13W2 CAP > Flashcards

U13W2 CAP Flashcards

1
Q

What is the mechanism of action of amlodipine?

A

Class: is a calcium ion channel blocker
Chem: small molecule, sihydropyridine
Pharm: Is a L-type voltage gated calcium channel gating inhibitor
Physiology: has a greater effect on smooth muscle than cardiac muscles, decreases Ca2+ mobilisation in sm. muscle, leads to vasodilation
Clinical: essential hypertension and angina.

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

What is the mechanism of action of clarithromycin?

A

Class: macrolide
Clinical: broad spectum against mainly gram positive bacteria.
Pharm: antagonist at 23s 50s subunit in bacterial ribosome
Physiology: inhibits protein synthesis by blocking the polypeptide exit tunel, which prevents peptide chain elongation.
Most peptides produces are short only 3-9 amino acids long.
Are bacteriostatic although can be bactericidal at high doses.

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

What is the mechanism of action of amoxicillin/flucloxacillin?

A

Class: penicillin
Clinical: A - wide spectrum beta lactam, gram positive and enterococci, Haemophilus and listeria
F - narrow spectrum, gram-positive particular skin and soft tissue but not MRSA
Pharm: Antagonist of transpeptidase enzymes (penicillin binding protein), located in the periplasmic space between peptidoglycan layer and the plasma membrane.
Forms a covalent bond between Beta lactam ring which mimics D-ala-D-ala on peptoglycan and serine residue in transpeptidase enzyeme
Physiology: Prevents crosslinking of peptoglycan, high internal osmotic pressure leads to cell lysis.

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

What are the main mechanism underpinning the risk factors for CAP?

A

Increased risk of exposure to pathogen
Impaired mucociliary clearance or decreases epithelial barrier integrity.
Impaire phagocytic function including alveolar macrophages and neutrophils
Impaired adaptive immunity.

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

What are some of the risk factors for pneumonia?

A
  1. Extreme age - babies, children, elderly - suffer from immunoscencenes or underdeveloped immune system - both share poor monocye/macrophage function, lack or diminished memory T cell function, poor tissue repair and diminished cytokine responses
  2. Smoking - impaired mucoscilliary escaltor, low grade inflammation in lungs damage integrity, inhibit macrophage response
  3. Co-morbidities - CF, asthma, heart conditions - weakened tolerance to illness, more vulnerable to atypical pathogens
  4. Compromised immune system - such as in flu, HIV/AIDs or post organ transplant.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the different types of causative pathogen for CAP?

A

Bacterial - norm streptococcus pneumoniae
Viral - influenza A
Fungal - pneumocystis, cryptococcis and aserpigillus

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

How can you differentiate between bacterial, viral and fungal pneumonia?

A

Viral v bacterial - v has slower symptom onset, also GIT symptoms, lower body temp, lack of purulent sputum
bacterial - sudden onset, purulent sputum, high-grade fever
Fungal - more variable symptoms may also experience weight loss and fatigue. Often have symptoms of underlying disease causing immunosuppression,

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

What are the different types of infections that staphylococcus aureus can cause?

A

Skin infections - impetigo, boils, scalded skin syndrome, cellulitis
Severe disease - endocarditis, pneumonia, sepsis, toxic shock syndrome
both community and hospital acquired pneumonia

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

How common are carriers of MRSA?

A

3% of the population are carriers of MRSA.

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

What features should be looked at when testing for staphylococcus aureus?

A

Gram-positive cocci in clusters
Catalase positive
Oxidase negative
Coagulase positive
Grows on CBA, MSA (red to yellow change), BPA and chromogenic agists
Inhibited on MacConkey agar (bile salts)

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

Name the organisms from the gram stain

A

Staphylococcus aureus.

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

What is the definition of Methicillin-Resistant Staphylococcus Aureus?

A

Strains with an MIC of 4µg/ml Oxacillin or more

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

What are the problems associated with MRSA?

A

Leading cause of hospital acquired infecrion.postop protheses
Causes a wide range of infections of the skin/soft tissue, bones and joints, pneumonia, endocarditis, bacteremia.
High mortality and morbidity
Significant length of stay and cost burden.

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

What is the test for catalase and what does it mean?

A

Tests for presence of catalse enzyme by the decomposition of hydrogen peroxide to release oxygen and water
Rapid formation of bubbles.
Bottle method - hydrogen peroxide in bottle, colony on side, flip bottle to cover colony with hydrogen peroxide observe for bubbles.
All staphyloccoci tend to be catalase positive

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

What is the test for oxidase and why is it important?

A

Used to test for presence of cytochrome C enzyme.
Can identify Neisseria gonorrhae and Pseudomonas, (pos) whilt staph and strep tend to be negative.
Oxidase bottle fill 3rd with distilled water to dissolve reagent.
Add drops of solution to filter paper in clean Petri dish
Use sterile method to move colony from agar plate to filter paper.
Purple colour within 5 to 10 seconds indicates oxidase positive.
TMPD is used as the oxidase reagent.

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

What is the test for coagulase?
What is its purpose?

A

Coagulases are enzymes that clot blood plasma.
Often follows a catalse test to differentiate between staph aureus (coag pos) and other staph species.
Saline drops on slide or test tube are emulsified with test organisms using a wire loop or wooden stick - observe for fibrin clot/string formation.

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

What are the different mechanism by which staphylococcus aureus can invade a host and cause infection?

A
  1. Enter bloodstream through open wound - may spread heamatogenously to distant site
  2. Weakened immune system - disrupts microbiome allows S.aureus to multiply unchecked, cause dysbiosis
  3. Seoncadry to viral infection which has damaged to mucosal linings of respiratory tract.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the virulence factors of staphylococcus aureus?

A
  1. alpha toxin - active metalloproteases, break adherens junction by cleaving E-cadherins, compromises actin skeleton and epithelial barrier integrity.
  2. Biofilm formation - such as on tampons in TSS - phenotype promotes antibiotic resistance.
  3. Phenol-soluble modulins - lysis of erythrocytes and leukocytes - compromise host immune defences.
  4. Abscess formation - difficult to treat with antibiotics.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does S. aureus tend to colonise a person?

A

Asymptomatic colonnization becomes pathogenic
Or rarely, norm in hospital environments - transfer from formites ot infected individuals
Main site of colonisation = the nares, also skin and intestine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the basic pathophysiology of community acquired pneumonia and lung remodelling?

A

Branching anatomy of the respiratory tract normally prevents inhlaed pathogens from reaching alveoli, this is aided by mucus, cough reflex, cilia, epithelial barrier, normal flora and immune surveillance, mucocilliary clearance (waft into pharnyx)
When alveolar macrophages are overwhelmed by a large inoculum of pathogens they release cyoktines and initiate and inflammatory cascade
Leukocytes invade the lung tissue, filling infected alveoli with purulent ecudates normally made from dead wbcs, tissue debris, and living or death pathogens (this impaired effective gase exchange).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is ventilator associated pneumonia?

A

Pneumonia is contracted after 48 hours of mechanical ventilation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does antibiotic treatment guidelines vary based on HAP?

A

Patients who are recently hospitalisied but do not have additional risk factors for MDR pathogens or HAP can be treated with standard antibiotic therapy for CAP, rather than broad spectrum antibiotics used in HAP MDR suspicision.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How useful is sputum cultures in identifying the causative organism in pneumonia?

A

CAP - most commonly bacteria or viruses
Sensitivity of sputum culture is highly variable
Up to 40% of cases are viral so often not identified by traditional microbial testing

24
Q

What pathogens are common causes of CAP in otherwise healthy patients?

A

Streptococcus pneumoniae then Haemophilus influenza are most common cause.
RSV, followed by influenza A and B are common viral causes

25
Q

What pathogens can cause CAP in patients with co-existing health problems?

A

Haemophlilus influenza - Common in COPD patients
Kelebsiella pneumonia - diabetics, alcoholics,
Pseudomonas aeruginose - CF patients.
Staphylococcus aureus - secondary to viral infection,

26
Q

What are some uncommon causes of CAP?

A

All sometimes called atypicals as tend not to respond to beta lactams.
Mycoplasm pneumonia - usually mild and rarely requires hospitalisation.
Chlamydia pneumonia - young adults following prolonged pharyngitis
Legionella pneumonia - humidifier, hot tub or air con
Also anerobes, GAS, Enterobacteriaceae, Pseudomonas aeruginose, moraxella catarrhalis are less common.

27
Q

What signs can indicate a legionella pneumophilia?

A

Vomiting
Diarrhea
Hyponatremia
Elevated LFTs.
Increased tactile fremitus due to consolidation
Bronchial breath sounds and crackles on ausculatation.

28
Q

What is meant by antimicrobial stewardship?

A

Coordinated interventions designed to improve and measure the appropriate use of antimicrobials by promoting selection of optimal antimicrobial drug regime, dose, duration of therapy and route of administration.

29
Q

What advice is included in antimicrobial stewarship for patients?

A

Advice on self-medication and health attitudes
Only take antibiotics when needed, stress that ineffective against viruses
Do not share medication with others or take others medication.
Make sure you finish the full course of antibiotics
Taking aspirin in health people
Do not save medications for later, talk to pharmacist about safely discarding leftover medicines.

30
Q

What are the key symptoms of CAP?

A

Dyspnoea
Cough +/- sputum
Pleuritic chest pain
Systemic fever and confusion.

31
Q

What are the key signs of CAP?

A

Tachypnoea
Cyanosis
Extra sounds
Crepitations
Dullness to percussion
Bronchial breathing
Hypoxaemia
Low BP and High Pulse

32
Q

What do different sputums look like and what do they indicate?

A

Mucoid - with and faomy common in COPD and asthma
Micropurulent - mild yellow/greeny/ large numbers of wbcs especially neutrophils, can indicate infection.
Purulent - thick thick pea soup, more severe infection, viral or bacterial.

33
Q

What does streptococcus pneumonia sputum look like?

A

Rust coloured

34
Q

What is an ambulatory emergency centre?

A

Same-day emergency care for none life threatenting emergency conditions as an alternative to hospital admission, clinic rather than bedded setting.
Provides assessment, diagnosis and treatment on same-day, aims to streamline patient access to services and reduce hospital bed/A&E demand.
May include patients who have had a brief overnight stay and are discharged, and patients who are being supported/followed up after early supported discharge.
Can be referred to be GP, NHS 111, ambulance or ED.

35
Q

What questions are often considereding when decinding if a patient is suitable to be referred to ambulatory emergency care clinic?

A

Are they sufficient stable to be managed in AEC? NEWS of 4 or less
Is the patient functionally capable of being managed in AEC whilst maintaining their safety, privacy and dignity?
Would the patient have been admitted in AEC was not available?
Is there an outpatient or community service that could more appropriately meet the patients needs?

36
Q

What laboratory and clinical investigations should be ordered for a patient with suspected pneumonia?

A

Oxygenation saturations and ABGs
CXR for accurate diagnosis
Blood test (U&Es for severity assessment, CRP for diagnosis and baseline, FBC for inflammation, LFTs drug dosing and legionella screening)
Microbial testing - see own card

37
Q

What microbial testing should be ordered for a patient with suspected pneumonia?

A

Sputum for culture and sensitivity
Blood for culture and sensitivity
Urine for legionella and streptococcal antigen
Viral testing - PCR
Serology - for antibiotics against microbes.

38
Q

How should you take an arterial blood gas from a patient?

A

Norm intro
Check for contraindications - trauma, infection or skin abnormalities such as burn overlying the area, blood thiners, problems with clotting, warfarin med, allergies
Perform a modified Allens test
Palpate radial pulse and clean the skin
Wash hands, put on gloves and apron
Local anaesthetic
Expel herein through needle and insert into radial artery at 45 degrees, observe flashback and allow syringe to self fill
Immediate pressure
Thank patient and wash hands.

39
Q

What value of pO2 is indicative of respiratory failure?

A

Less than 8kPa
LEss than 60mmHg.

40
Q

What is the role of chest x-ray in diagnosing community acquired pneumonia?

A

First line imaging for pneumonia diagnosis
All patients admitted to hospital with suspected CAP should has CXR ASAP (4hrs) to confirm diagnosis as by BTS guidelines
Look for consolidation
Allows to evaluate severity of condition
May also identify unexpected findings such as lung abscess, pleural effusion, or co-existing conditions such as bronchial obstruction.

41
Q

What is the order details of a CXR for CAP?

A

Standrd view erect PA at full inspiration
May also request a lateral view
AP supine at bedside if immobile or unstable
Examine systematically using ABCDE approach
Airway, breathing (lung and pleura), cardiac, diaphragm and angles, everything else.

42
Q

Identify the features on this normal Chest XR.

A

Trachea
Carina
Right and left main bronchi
Right and left hilar structures
Right horizontal fissure
Right cardiac border formed be right atrium
Left cardiac border formed by left ventricle
Aortic knuckle
Descending thoracic aorta
Right paratracheal line
Right and left hemidiaphragms
Costrophrenic angles
Gastric air bubble
Gas in colon

43
Q

What is shown on the CXR?

A

Lobar pneumonia left lower lobe

44
Q

What is shown on the CXR?

A

Bilobar pneumonia
With air bronchograms

45
Q

What is the general management of a CAP patient?

A

Rest, keep hydrates and dont smoke
Analgesics - encourage to cough up
Should decide on antibiotics choice including route based on severity, likely pathogen and allergies.

46
Q

What additional management is required for a hospitalised CAP patient?

A

Oxygen is required
IV fluids if volume depleted
Antibiotics - dual therapy
Should review daily with a view to de-escalate, should monitor patients progress and microbiology results.

47
Q

What is the CURB 65 score?

A

Calculator for pneumonia severity index.
Confusion
Urea above 7mmol/L
Resp rate above or equal to 30 bpm
BP below or equal to S 90mmHg or D 60mmHg.
Age more than or equal to 65yrs.

48
Q

What is the important epidemiology in CAP?

A

1% of adults will have CAP annually.
CAP diagnosed in 12% of adults who present to GP with LRTI
Up to 42% admitted to hospital and up to 14% die
Most common cause of sepsis
For most causes the microbe is never identified.

49
Q

What guidelines are issued by the British thoracic society to help manage CAP?

A

Perform CXR within 4 hours of admission
Assess oxygen and prescribe target range for oxygen
Calculate CURB 65 score if CXR confirms diagnosis
Administer appropriate antibiotics within 4 hours of admission.
These guidelines make up the CAP care bundle.

50
Q

What public education is involved around healthy people taking aspirin?

A

High risk of bleeding - particualarly from GIT ulcers
Aspirin - anti-inflammatory effects, however could also slow bacterial growth reducing the effectiveness of antibacterial such as anbioitics.

51
Q

What is healthism?

A

A way of thinking that sees health, healthy making decisions as superior.
Illness can be seen as a failure.
Puts responsibility of health on the individual, can increase discrimination against chronic illness.
Leads to high levels of stress and anxiety in order to prevent illness.

52
Q

What is OCD?

A

A mental health condition where a person has obsessive thoughts and compulsive behaviours.
Obsession - unwanted or unpleasant thought ot urge that repeatedly enters mind causing feeling of anxiety, disgust or unease
Compulsion - repetitive behaviour or mental act you feel you need to do to temporarily relieve unpleasant feelings brought on by obsessive thoughts.

53
Q

How does OCD impact on stress and anxiety?

A

Decreases QoL - disrupts day-to-day life, time consuming compulsions and avoiding situations that trigger OCD
Interference with work and relationships
Increases stress and anxiety due to constant worry
Fear losing control
Feeling ashamed or lonely.
Social isolating as difficult for other people to understand.

54
Q

What is mysophobia?

A

An extreme fear of germs, causing an overwhelming obsession with contamination or uncleanliness.
Aka germophobia
Associated with OCD - persistent an dintrusive thoughts about contamination
Leads to avoidance behaviour, may over washing hands, refusal to enter potentially contaminated environments and overusing hand sanitizers.

55
Q

What is the pathological process undermining the infection and response in CAP?

A
  1. arrival of the pathogen in alveolar space (inhaled or haematological spread), overcomes defence mechanisms including resident alveolar macrophages, cough reflex, IgA neutralising properties, surfactant containing antimicrobials and mucociliary escalator.
  2. Uncontrolled multiplication of pathogen, results in colonisation of the airways.
  3. Local production of cytokines and chemokines (IL-8) primarily by alveolar macrophages. In response to pathogen toxins and DAMPs release from damaged alveoli. Present antigen to activate T/B cells. Macro produce G-CSF stimulate bone marrow to produce more lymphocytes.
    Example mediaors include leukotrienes which increase cap perm.
  4. Neutrophil recruitment into alveolar airspace and introduction of cytokines into systemic circulation
  5. Generation of alveolar exudate, including RBCs, fibrin and lymphocytes and dead cells/tissue debris - this is consolidation and appears as congestion on the CXR. Fluid and thickened alveolar walls.
  6. This impaired gas exchange leading to hypoxemia and respiratory distress

Year 2 PBL (27 decks)

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