Brainscape's Knowledge GenomeTM

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


See full index

infec y3s1 > IC16 Lower Respiratory Tract Infections > Flashcards

IC16 Lower Respiratory Tract Infections Flashcards

1
Q

acute bronchitis: clinical presentation

A

Acute cough (<3 weeks)
Due to inflammation of trachea & lower airways

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

acute bronchitis: diagnostic test

A

not required

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

acute bronchitis: treatment

when to give AB

A
  • Considered self-limiting; usually not recommended for treatment regardless of duration of cough
  • To use AB only if bacterial infection suspected
    To perform further diagnostics to confirm bacterial infection ⇒ treat the infection (not acute bronchitis)
  • Management of symptoms with pharmacological/ non-pharmacological methods
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

acute bronchitis: monitoring outcomes

how long it lasts & when to see doctor

A
  • Cough usually last for at least 3 weeks + AB use does not hasten resolution of cough
    Better to use cough suppressants as symptomatic treatment
  • To see doctor if develop fever, SOB/ chest pain, cough increase in extent/ frequency or cough persisting beyond 3 weeks
    Possible bacterial superinfection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

pneumonia: background (description)

A

Infection of lung parenchyma
Due to proliferation of microbial pathogens in alveolar level

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

pneumonia: risk factors

A

Smoking → suppressed neutrophil function & damages lung epithelium
Consists of MCC to remove pathogens by lungs/ GIT → damaged = loss of function of MCC

Chronic lung conditions: COPD, asthma, lung cancer
Destroys lung tissue → pathogens have more niduses for infection

Immune suppression: HIV, sepsis, glucocorticoids, chemotherapy
Suppression of immune response

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

HAP/VAP: RF infection control

A

Lack of hand hygiene compliance
Contaminated respiratory care devices

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

pneumonia: methods for exposure to pathogens

A

Aspiration of oropharyngeal secretions
Bacteria in oropharyngeal secretions enter lungs from mouth due to swallowing impairment
Substances flow from GIT to lungs → introduction of pathogen into respiratory tract
Inhalation of aerosols

Aerosol droplets containing bacteria

Haematological spreading
Bacteremia from extra-pulmonary source

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

HAP/VAP: types of Risk factors

A
  1. patient related
  2. infection control
  3. healthcare-associated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

pneumonia: effects of infection (process of getting pneumonia)

A
  1. Exposure to pathogen via inhalation, aspiration, contagious or haematological mechanisms
    Normally cleared by innate immunity → but presence of risk factors lowers the ability of doing so
  2. Susceptible host &/ or virulent pathogen
    May invade tissues ⇒ infection
  3. Proliferation of microbe in lower airways & alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

HAP/VAP: RF patient related

A

Elderly
Smoking
COPD, cancer, immunosuppression
Prolonged hospitalisation
Coma, impaired consciousness –> Inability to breathe independently
Malnutrition

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

HAP/VAP: RF healthcare

A
  • Prior AB use
    Altered normal flora; bacteria present can cause infection
  • Sedatives
  • Opioid analgesics
  • Mechanical ventilation
    Bacteria can enter directly into lungs
    To ensure proper hand hygiene
  • Supine position
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

HAP/VAP: prevention

General; VAP specific

A

General
Practise consistent hand hygiene
Judicious use of AB & medications with sedative effects

VAP-specific
* Limit duration of mechanical ventilation → reduce risk of biofilm formation
To take off ventilator ASAP
* Minimise duration & deep levels of sedation
* Elevate head by 30 degrees (helps with breathing)

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

pneumonia: classification definitions

CAP, HAP, VAP

A

CAP
Onset in community OR
<48 hours after hospital admissions

HAP
Onset ≥ 48 hours after hospital admission

VAP
Onset ≥ 48 hours after mechanical ventilation
Requires sedative drugs
Direct insertion of tubes into lungs

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

CAP RF

A

History of pneumonia
Smoking, chronic respiratory diseases, immunosuppression

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

CAP prevention method

A

Smoking cessation & immunisations (influenza & pneumococcal)

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

CAP: causative organisms

General for all

A

Streptococcus pneumoniae
Haemophilus Influenzae

Atypical organisms
Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila

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

CAP: causative organisms
inpatient, non-severe

A

based on risk factors, MRSA & Pseudomonas aeruginosa

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

CAP: causative organisms
inpatient, severe

A

Staphylococcus aureus
Other Gram-negative bacilli: Klebsiella pneumonia, Burkholderia pseudomallei (High occurrence in tropical countries → derived from soil during rainy/ wet weathers)

Based on risk factors, MRSA & Pseudomonas aeruginosa

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

HAP/VAP: causative organisms

also RF to lookout for; mortality risk

A

Pseudomonas
Staphylococcus aureus
Enterobacteriaceae spp
MRSA

RF
* MDRO risk factors
* Mortality risk factors → more sick = lower threshold to start on broad spectrum to target resistant strains

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

HAP/ VAP possible outcomes

use of AB & hospitalisation

A
  • Poor predictor of resistant pathogens/ worse outcomes
  • Significant healthcare costs
    Prolonged hospitalisation
    Accounts ≥ 50% of inpatient antibiotic use
  • Will have systemic + local signs & symptoms
  • May lead to overuse of broad-spectrum AB
  • Need to cover drug-resistant pathogens + de-escalate treatment if culture is negative
22
Q

CAP: risk stratification methods

A
  1. CURBS-65
  2. IDSA
23
Q

CAP: CURBS-65 Risk stratification

Criterias

A

Confusion
Urea >7 mmol/L
RR >30 bpm
BP (SBP <90mmHg, DBP <60mmHg)

Elderly >65 years

24
Q

CAP: CURBS-65 Risk stratification

scoring

A
  • Score 0 or 1: outpatient
  • Score 2: inpatient
  • Score ≥ 3: inpatient, consider ICU
    Might require intubation due to breathlessness & low o2 levels
25
Q

CAP: IDSA criterias

A

Major & minor

26
Q

CAP: IDSA major criteria

A
  • Mechanical ventilation
    Intubation required due to low o2 saturation
  • Septic shock requiring vasoactive medications
    Presence of hemodynamic instability
    To sustain BP
27
Q

CAP: IDSA minor criteria

RMOCLUHH

A
  • RR ≥ 30 breaths/min
  • PaO2/FiO2 ≤ 250 (ICU)
  • Multilobar infiltrates (X-ray)
    Might enter shock OR
    Require mechanical ventilation ⇒ major criteria
  • Confusion/disorientation
  • Uremia (urea > 7 mmol/L)
  • Leukopenia (WBC < 4 x 10^9/L)
    Not due to chemotherapy; must be due to infection
  • Hypothermia (core temperature < 36degC)
  • Hypotension requiring aggressive fluid resuscitation
    First line treatment
    Require vasopressors if do not work ⇒ major criteria
28
Q

CAP therapy: outpatient, no comorbidities

organism to cover + drug selection

A

Streptococcus pneumoniae

PO
ꞵ-lactam: Amoxicillin 1 g q8H
High dose → precaution for penicillinase resistant streptococcus pneumoniae
Narrow spectrum

Allergy or C/I for ꞵ-lactam
Respiratory FQ: levofloxacin/ moxifloxacin

29
Q

CAP therapy: outpatient, with comorbidities

organism to cover + drug selection

A

Streptococcus pneumoniae, Haemophilus influenzae
(Atypical organisms) Mycoplasma pneumoniae, Chlamydophila Pneumoniae,
Legionella pneumophila

PO
1. ꞵ-lactam: Amoxicillin/ clavulanate OR Cefuroxime

PLUS (either one)
2. Macrolide: clarithromycin OR azithromycin
ADR: QTc prolongation

2. Doxycycline
Targets atypical organisms
ADR: esophagitis & photosensitivity

Allergy or C/I for ꞵ-lactam
Respiratory FQ: levofloxacin/ moxifloxacin

30
Q

CAP therapy: inpatient, non-severe

organism to cover + drug selection

A

Same as CAP outpatient, with comorbidities but IV drug administration

MRSA risk factors
ADD ON
IV Vancomycin OR
IV/ PO linezolid

P.aeruginosa risk factors
Modify regimen to include pseudomonas coverage
Piperacillin/tazobactam, Ceftazidime, Cefepime, Meropenem, Levofloxacin

31
Q

CAP therapy: inpatient, severe

organism to cover + drug selection

A

(same 5 key bacteria, with additional)
Staphylococcus aureus, Klebsiella pneumonia, Burkholderia pseudomallei

IV
1. ꞵ-lactam: Amoxicillin/ clavulanate OR penicillin G

PLUS
2. Ceftazidime → covers H.influenzae & burkholderia pseudomallei

PLUS
3. Macrolides: clarithromycin OR azithromycin → Covers atypical & staphylococcus aureus

Alternative: Allergy or C/I for ꞵ-lactam
1. Respiratory FQ: levofloxacin/ moxifloxacin
PLUS
2. Ceftazidime

MRSA Risk factor
ADD ON
IV Vancomycin OR
IV/ PO linezolid

32
Q

CAP therapy: other treatment considerations
Inclusion of anaerobic cover

A

If lung abscess/ empyema reported in radiology investigations

Possible additions:
IV/ PO metronidazole
IV/ PO clindamycin → might have increased resistance in bacteroides fragillus

33
Q

CAP therapy: other treatment considerations
Influenza management

A
  • Add empiric oseltamivir (to current AB regimen) → if suspect influenza
    To initiate ASAP (best within first 48 hour, up to 5 days) of symptom onset
  • Patients with positive PCR
    Complete 5 days course of oseltamivir
    Consider discontinuing AB at 48-72 hours if no evidence of bacterial pathogen
    Negative cultures, low procalcitonin levels (<0.25), early clinical stability
34
Q

CAP therapy: other treatment considerations
Respiratory FQ

reason why not first line therapy

A

Increases AE
Tendonitis, tendon rupture, neuropathy, QTc prolongation, CNS disturbances, hypoglycemia

Development of resistance with overuse

Important to preserve for other gram negative infections (levofloxacin & ciprofloxacin)
* Alternative Pseudomonas coverage with severe penicillin allergies
* Only PO options for covering P.aeruginosa

May delay diagnosis of TB (differential diagnosis)
* FQ have activity against TB ⇒ cannot obtain proper sputum culture
* Undesirable monotherapy if TB → causes resistance

35
Q

CAP therapy: other treatment considerations
Adjunctive corticosteroid therapy

A

to reduce inflammation in lungs
To add if shock resistant to fluid resuscitation & vasopressor support

36
Q

CAP therapy: Treatment duration
Requirements for stopping after 5 days

A

Resolution of vital sign abnormalities
* HR, RR, BP, oxygen saturation, temperature

Ability to maintain oral intake
Baseline mental status

37
Q

CAP therapy: de-escalation
Suitable patients

A

Hemodynamically stable → normal BP, RR
Improving clinically
Ability to ingest oral medications

38
Q

CAP therapy: de-escalation
methods

positive culture vs no positive culture

A

Positive culture
Use AST to select narrower spectrum &/or PO AB(s)

No positive cultures
* De-escalation: empiric cover for MRSA, P.aeruginosa or burkholderia pseudomallei can be stopped in 48 hours if pathogen not isolated & patient improving
* IV-to-oral: use same AB/ another AB from same class
* General coverage: Strep pneumoniae, H.influenzae, atypical bacteria

39
Q

CAP therapy: Treatment duration
Longer courses of AB therapy

A
  • CAP complicated with other deep-seated infections
    ie: meningitis, lung abscess ⇒ requires ~2-3 weeks
  • Infection with other less common pathogens
    ie: Burkholderia pseudomallei, Mycobacterium tuberculosis or endemic fungi
40
Q

CAP therapy: Treatment duration

A

Minimum 5 days therapy
7 days if suspected/ proven MRSA or P.aeruginosa

41
Q

HAP/VAP: MRSA considerations

A
  • Prior IV AB use within 90 days
  • Isolation of MRSA in 1 last year
  • Hospitalisation in unit where >20% S.aureus are MRSA
  • Prevalence of MRSA in hospital unknown, but patient is at high risk of mortality
    ie: need ventilatory support due to HAP & Septic shock
  • More sick = lower threshold to start on broad spectrum
42
Q

HAP/VAP: key organisms to cover

A

P.aeruginosa, staphylococcus aureus, enterobacteriales

43
Q

HAP/VAP: Pseudomonas & Gram negative cover

A

Use of double (2) antipseudomonal AB from different classes for empiric treatment of suspected HAP/ VAP in patients ⇒ to extend coverage

  • Risk factor for AM resistance
    Prior IV AB use within 90 days
    Acute renal replacement therapy prior to VAP onset
    (May get septic shock & renal function may stop)
    Isolation of P.aeruginosa in last 1 year
  • Hospitalisation in unit where >10% of pseudomonas are resistant to agent considered as monotherapy
  • Prevalence of P.aeruginosa in hospital unknown but patient is at high risk of mortality
    ie: need ventilatory support due to HAP & Septic shock
  • AVOID use of AG as sole antipseudomonal agent
    Sicker patients → bacteremia & pneumonia: may have higher mortality
44
Q

HAP/VAP: AB selections
Pseudomonas aeruginosa
Other Gram negative, enterobacter spp, klebsiella spp
E.coli

A
  1. ꞵ-lactam:
    * piperacillin/ tazobactam
    * Cefepime
    * Ceftazidime
    not preferred due to ESBL risk
    Avoid use if MRSA cover not required
    * Meropenem, imipenem

AND/OR
2. Antipseudomonal FQ: Levofloxacin/ ciprofloxacin

OR
Aminoglycosides (amikacin) → partner agent; have breakpoint of pseudomonas

45
Q

HAP/VAP: AB selections
MRSA

A

ADD ON
IV vancomycin
IV/ PO linezolid

46
Q

HAP/VAP: De-escalation
suitable individuals

A

Hemodynamically stable → normal BP, RR
Improving clinically
Ability to ingest oral medications

47
Q

HAP/VAP: De-escalation
methods

positive vs no positive culture

A

Positive cultures
* Use AST to select narrower spectrum &/or PO AB(s)
* For P.aeruginosa ⇒ to use single antipseudomonal agent
The one that bacteria is susceptible

No positive cultures
* maintain coverage according to local HAP/VAP antibiogram OR
(if antibiogram unavailable), P.aeruginosa, enterobacteriales, enteric Gram negative & MSSA
* Removal of vancomycin if no MRSA indicated
* May not be possible for patients with significant risk of MSSA
* IV-to-oral conversion ⇒ ideal

48
Q

HAP/VAP: Treatment duration

when allowed to stop; when longer therapy required

A

7 days regardless of pathogen

Clinically stable; able to stop
* Resolution of vital sign abnormalities
HR, RR, BP, oxygen saturation, temperature
* HAP → Baseline mental status
* VAP → can still be off AB even with ventilator on, as long as labs & vital signs are normal

Longer courses of AB therapy
* CAP complicated with other deep-seated infections
ie: meningitis, lung abscess ⇒ requires ~2-3 weeks

49
Q

monitoring therapy of CAP, HAP & VAP

Therapeutic response, escalation of AB

A
  • Most achieve clinical stability within first 48-72 hours
    elderly/ those with comorbidities may take longer
  • Should not escalate AB therapy in first 72 hours
    Unless culture-directed (current AB cannot cover bacteria) OR
    Significant clinical deterioration
50
Q

monitoring therapy of CAP, HAP & VAP

diagnostic tests

A

to repeat only if clinical deterioration
To check for new pneumonia/ if pneumonia spread

infec y3s1 (7 decks)

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