12. Respiratory Tract Infections Flashcards
What are the risk factors for someone who presents with a cough
History of smoking (pack years)
Occupational history
Medication history (ACE inhibitors, beta blockers, aspirin)
history of contact with someone who has TB
Name some differentials diagnosis of an acute cough (less than 3 weeks)
Influenza COVID 19 Viral URTI pneumonia lung cancer pericarditis infective exacerbation of COPD bronchiectasis TB SBE (subacute bacterial endocarditis) PE
when taking a history of someone with a new onset cough, what do you want to know about the cough
the onset and duration of the cough
wether it is productive/non productive
the timing of the cough ie is it worse at night or worse with the seasons
any associated symptoms
if there is sputum production the colour/amount of sputum
In someone with a URTI what associated symptoms would you expect them to have which would help you to differentiate this
rhinorrea ( production of watery, mucus, nasal discharge)
odynphagia (painful swallowing)
myalgia (muscle discomfort
fever
if someone has a productive cough then what differentials would you be thinking of
pneumonia bronchitis bronchiectasis pulmonary odema TB
if someone has a non-productive dry cough then what differentials would you be thinking of
asthma
interstitial lung disease (one that causes scarring of the lung)
viral pneumonia
What are the differentiating symptoms of COVID 19
fever
SOB
dry cough
anosmia
what are the differentiating symptoms of influenza
general aches and pains, autumn and winter timing
what are the differentiating symptoms of a viral URTI
sore throat, nasal congestion, cough and feeling generally unwell
what are the differentiating factors of pneumonia
sputum is green yellow brown fever chest pain SOB unwell patient
what are the differentiating factors of lung cancer
haemoptysis
weight loss
persistant cough
ex smoker
what are the differentiating factors of pericarditis
chest pain that is relieved on sitting forwards, usually following a viral infection
what are the differentiating factors of infective exacerbation of COPD
increased sputum production and SOB
background of COPD or smoking history
what are the differentiating factors of bronchhiectasiss
chronic productive cough, breathlessness
what are the differentiating factors of TB
swinging fever weight loss anorexia productive cough haemoptysis contact with TB case high risk person (country of birth, homeless, immunosuppression)
what are the differentiating factors of PE
sudden onset of sharp pain felt when breathing in, breathlessness, haemoptysis
When should you think: could this be sepsis?
for a person of any age with a possible infection, even if they do not have a high temperature
What acute phase protein would be raised if someone has an infection and what blood marker
CRP & WCC
what two bacterial antigens can you test from someones urine
pneumococcal & legionella antigen
what is lactate a product of
anaerobic respiration and so would be increased in sepsis and shock
How can you describe CAP simply
signs of lower respiratory tract infection (fever, cough, phlegm, crepitations or bronchial breathing) + CXR changes
what are the red flags to ask about when someone presents with a cough
persistent fever, night sweats and weight loss
Dyspnoea ( CCF, asthma, COPD, interstitial lung disease)
hemoptysis
severe pleuritic pain
history of contact with someone with HIV or TB
What is the CURB-65 score
this is used to assess the patients risk of mortality of CAP to help determine outpatient vs inpatient treatment
what does CURB65 stand for
C- Confusion U- urea greater than 7 mmol/L R- RR more than 30 B- Blood pressure systolic less than 90 or diastolic less than 60 65- if the person is 65 or older
how does the CURB65 score relate to management
score of 0-1 then likely suitable for home treatment
score of 2 then consider hospital supervised treatment
score of 3 or more then manage in hospital as severe pneumonia
What is the NEWS2 score
this is 6 simple physiological parameters that form the basis of the scoring system RR O2 Systolic BP pulse level of consciousness/new confusion temperature
how would you describe pneumonia simply
an infection of the lung tissue that causes inflammation of the lung tissue and sputum filling the airways and alveoli
what does pneumonia show up as on an x ray
consolidation
how does pneumonia usually present (symptoms)
SOB
cough productive of sputum
fever
haemoptysis (coughing up blood)
pleuritic chest pain (sharp chest pain that is worse on inspiration)
Delirium (acute confusion associated with the infection)
Sepsis
What signs indicate pneumonia and possible sepsis secondary to the pneumonia
Tachypnoea (raised RR)
tachycardia (rasied HR)
hypoxia (low O2)
hypotension (shock)
fever
confusion
bronchial breath sounds on inspiration and expiration (caused by consolidation of the lung tissue around the airway)
focal coarse crackles (air passing through sputum in the airways similar to using a straw to blow into a drink)
dullness to percussion due to lung tissue collapse or consolidation
in the CURB-65 what parameter do you not count if you are out of hospital
urea
What are the common bacterial causes of pneumonia
Streptococcus pneumonia (50%)
haemophilus influenza (20%)
Moraxella catarrhalis in immunocompromised patients or those with chronic pulmonary disease
Pseudomonas aeruginosa in patients with cystic fibrosis or bronchiectasis
Staphylococcus aureus in patients with CF
what is an atypical pneumonia and how is it treated
pneumonia caused by an organism that cannot be cultured in the normal way or detected using a gram stain
Don’t respond to penicillins can be treated with macrolides (e.g. clarithomycin), fluoroquinolones (e.g. levofloxacin) or tetracyclines (e.g. doxycycline).
what kind of bacteria is streptococcus pneumoniae
gram positive coccus
what kind of bacteria is haemophilius influenza
gram negative bacillus
Name the 5 causes of atypical pneumonia
hint the pneumonic is ‘legions of psittacis MCQ
M- mycoplasma pneumoniae
C- Chlamydydophila pneumoniae
Q- Q fever (corella burrnetti)
Legionella
Chlamydia pscittaci
what is legionella pneumophilia caused by and what is the typical exam patient
infected water supply or air conditioning units
typical exam patient has recently has a cheap hotel holiday and presents with hyponatraemia
what is mycoplasma pneumonia and what kind of patient does it cause neurological symptoms
milder pneumonia that causes a rash called erythema multiform which is characterised by varying sized ‘target lesions’ formed by pink rings with pale centres
can cause neurological symptoms in young patient
what is the common presentations of chlamoydophila pneumonia
school aged child with a mild to moderate chronic pneumonia and wheeze
what is the typical exam patient who presents with Q fever (coxiella burnetii)
linked to exposure to animals and their bodily fluids so MCQ patient is a farmer with a flu like illness
how is chlamydia psittaci usually contracted and what is the typical MCQ patient
contracted from contact with infected birds
MCQ patient is from a parrot owner
what fungal pneumonia can occur in patients that are immunocomprised
pneumocystis jiroveci (PCP) particularly important in patients with poorly controlled or new HIV with a low CD4 count
how does fungal penumonia usually present in an immunocompromised patient
dry cough, SOB on exertion and night sweats
what is the treatment for fungal pneumocystis jiroveci (PCP)
co-trimoxazole known by the brand name Septrin
what investigations would you want to do in someone that you suspect has pneumonia
chest X ray FBC U&Es CRP sputum culture blood culture legionella and pneumococcal urinary antigens
should always follow local area guidelines on antibiotic use however what is the broad treatment of the following
mild CAP
moderate to severe CAP
mild CAP: 5 day course of oral antibiotics (amoxicillin or macrolide)
moderate to severe CAP: 7-10 day course of dual antibiotics (amoxicillin and macrolide)
what are some common examples of macrocodes
azithromycin, clarithromycin, erythromycin, and roxithromycin
what are the main complications of pneumonia
sepsis pleural effusion empyema lung abscess death • Venous thromboembolism • Worsening of comorbidities o AF, heart failure, kidney failure, worsening of respiratory failure (COPD)
true or false: the higher up the infection, the more likely it is to be viral
true
name some common URTI
primarily viral common cold sinusitis pharyngitis laryngitis
name some common LRTIs
viral and bacterial acute bronchitis (COPD exacerbation) exacerbation of bronchiectasis pneumonia (lung abscess and empyema) TB influenza
Why does pneumonia show consolidation on the chest X ray
it is where there has been a mass infiltration of inflammatory cells and so the alveoli are filled with neutrophils
What are the main classifications of CAP
o G+ bacteria, mycoplasma, influenza
what are the main classifications of HAP
o Subtype is Ventilator-associated pneumonia (VAP)
o G- bacteria, Staph. Aures
what are the main classifications of pneumonia in the immunosuprresed host
o Unusual organisms, fungi
what are the main classifications of aspiration pneumonia
o Chemical pneumonitis, mixed flora
Name some potential findings in someone with CAP
- Temperature
- Tachypnoea
- Dull percussion
- Bronchial breathing
- Focal crackles
- Mental confusion
Name some symptoms of someone presenting with new onset CAP
- Cough with purulent sputum (blood)
- Rigors and fever
- Dyspnoea
- Chest pain (pleuritic, sudden onset)
- Abdominal pain
- Confusion (elderly, multimorbid patient)
Again name the 2 main antigens that you test for in the urine
pneumococcus and legionella
Name some common oral antibiotics
amoxicillin (alternatively doxycycline or clarithromycin(
Name the common treatment for severe pneumonia in hospital
a broad-spectrum beta-lacamase stable antibiotics such as amoxiclav together with a macrolide
What are the main side effects of antibiotics
usual side effects (diarrhoea)
C difficile infection
future antimicrobial resistance
sputum in pneumococcal pneumonia is characteristically what colour
rust/red
why does someone with pneumonia get SOB
alveoli become filled with pus which impairs gas exchange
what common chest pain do pt with pneumonia get
commonly pleuritic in nature and worse when coughing
what are some other non-pulmonary signs of pneumonia
confusion, abdo pain, diarhhoea and vomitting
Myalgia (pain or tenderness of the muscles) and arthralgia (discomfort of the joints) are common, especially in which infections
legionella or mycoplasma
what is the major red flag conditions in someone with pneumonia
sepsis
what is sepsis
Sepsis is the body’s extreme response to an infection. It is a life-threatening medical emergency. Sepsis happens when an infection you already have —in your skin, lungs, urinary tract, or somewhere else—triggers a chain reaction throughout your body
Diagnosisng pneumonia:
what could the FBC show
WCC increases in acute infections neutrophillia in bacterial infections neutropenia in viral infections lymphopenia indicates severe infections Hb: anaemia can complicate pneumonia high or low platelets can be indicative of inflammatory process
Diagnosisng pneumonia:
what could U&E show
urea and creatinine could be raised in AKI which could be a sign of sepsis
Diagnosisng pneumonia:
why would LFT be deranged q
can be a reflection of reduction in liver perfusion associated with sepsis
Diagnosisng pneumonia:
what inflammatory marker would be raised
CRP c reative protein
it is an acute phase protein that is produced by the liver in response to infection of trauma
higher levels indicate infection whereas lower levels are seen in inflammatory conditions and malignancies
what measurement is used as a general marker of illness severity and is used in sepsis scoring system
lactate as it is a product of anaerobic respiration
what is the limitation of a CXR
cannot distinguish the different causes of pneumonia based on the CXR alone
in what situations would a CT scan be performed
in cases where. lung abscess or empyema are suspected
when should blood cultures be taken
any patient with a fever in hospital
PCR can detect which kind of pathogens
o Non-culturable pathogens (viruses, atypical bacterial causes of pneumonia and pneumocystis jivoreci) and slowly growing pathogens (M. tuberculosis) can be detected and identified from respiratory samples by PCR
what is the infective organism that causes TB
mycobacterium acid-fast bacillus AFB
what should patients presenting with pneumonia be offered a HIV test
this is a common presentation of HIV in an undiagnosed individual
why cant you use a penicillin to treat an atypical cause. of pneumonia
they don’t process a cell wall on which penicillins or cephalosporins can act
typical causes of CAP are
streptococcus pneumonia
haemophilus influenza
klebsiella pneumoniae
staph. aures
IVDU and chronic lung pathology individuals are at risk from getting which causative agent of pneumonia ?
streptococcus pneumonia
haemophilus influenza
klebsiella pneumoniae
staph. aures
Staph. aures
Which causative agent of pneumonia is a commensal organism of the GI
elderly patient and people with co morbidities. or alcohol excess are at risk from
streptococcus pneumonia
haemophilus influenza
klebsiella pneumoniae
staph. aures
klebsiella pneumoniae
what are the most common viral causes of pneumonia
influenza A and B
however coronaviruses should be considered
Pneumonia due to influenza is often complicated with a post viral superinfection with bacteria or in severe cases with fungi like aspergillus
in the UK what is the most common cause of fungal pneumonia
pneumocystis jivoreci
what is the most common complication of pneumonia that complicates around 50% of cases
pleural effusion
note that sepsis can also complicate pneumonia
how does the causative agent differ in children
- Neonates are at risk of pneumonia caused by E.coli, group B streptococcus and listeria monocytogenes
- Between 1-6 months by chlamydia trachomatis, S.aureus and respiratory syncytial virus (RSV)
- From 6 months to 5 years the most common causes of pneumonia are RSV and para-influenzas virus
how do you define hospital acquired pneumonia
new onset of symptoms along with a compatable X-ray developing more than 48 hours after the patients admission to hospital
What is VAP
ventilator acquired pneumonia
What is the different between early and late onset HAP
o Early onset occurs within 4-5 days of admission and is usually caused by antibiotic-sensitive community organisms
o Late onset infection is more likely to be caused by antibiotic resistant hospital pathogens
what specimen samples can you take to look for infection
- Sputum
- Broncho-alveolar lavage: in ventilated patients, direct sampling of deep respiratory secretions is possible and produces good quality results
what are the risk factors for HAP
- ICU stay, mechanical ventilation
- Prolonged hospital or ICU stay
- Severe underlying illness, multi co-morbidities
- Underlying respiratory disease eg COPD, asthma
- Abdominal surgery, vomiting/aspiration
what is the sepsis 6
o Give high flow oxygen o Take blood cultures o Give IV antibiotics o Give a fluid challenge o Measure lactate o Measure urine output
in a FBC;
is neutrophillia common in bacteria or viral causes
bacterial
in a FBC;
is neutropenia common in bacterial or viral causes
viral
in a. FBC
what is lymphopenia suggestive of
severe infections
when dealing with HAP the common organisms that should be considered are
Staphylococci (including MRSA)
enterococci
Gram negative bacili (such as E-coli or pseudomonas
NICE. guidelines recommend which antibiotics as first line for severe HAP and which antibiotics for non-severe HAP
tazocin
co-amoxiclav
which lobe is aspiration pneumonia most common in and why
the right lobe as the right main bronchus is straighter from the trachea compared to the left
Answer with effusion, consolidation or both;
which produce opacification of the lung field
both
Answer with effusion, consolidation or both;
the margins of opacification are not as clear
consolidation
Answer with effusion, consolidation or both;
the margins of opacification are quite clear
effusion
Answer with effusion, consolidation or both;
the opacification is dense are there are non markings visible in the lung field
effusion
Answer with effusion, consolidation or both;
you can see air bronchograms, so the opacification is not dense
consolidation
