Pulmonary Infection Flashcards
Mr and Mrs Jones are both 65 and live together
Mr Jones is an ex-smoker with a daily cough productive of clear sputum and fixed airflow obstruction with an FEV1 48% predicted; Mrs Jones has never smoked, does not have asthma and is normally fit and active
They both develop a rhinovirus infection of their nose and throat, and both then develop a cough productive of yellow sputum; Mr Jones is more breathless and wheezy than usual, while Mrs Jones is well apart from the cough and sputum
What are the possible pathological processes in Mr and Mrs Jones? What are the likely anatomical site(s) of infection?
Cough productive of yellow sputum CAN occur with a cold, but often indicates there is a LRTI as well
Mr Jones’ mucociliary escalator is impaired so his infection is likely to go lower; his COPD also means that he is likely to be more functionally impaired both at normal and in the setting of infection
Because most cases of acute bronchitis are viral, it is likely Mrs Jones has an acute viral bronchitis and does not require treatment besides rest (self-limiting infection)
However, due to Mr Jones’ pre-existing functional impairment (and the further impairment of his cilia by the initial rhinovirus infection), Mr Jones could have a secondary bacterial infection
Would you expect a fever in acute bronchitis?
No, not normally
Mr and Mrs Jones developed a rhinovirus infection of the nose and throat, later complicated by a cough productive of yellow sputum
Mr Jones O/E: afebrile, RR 24, increased WOB, SaO2 94% on RA, reduced breath sounds both lungs, scattered wheezes, basal crepitations (cleared with coughing), CXR performed
Mrs Jones O/E: afebrile, RR 18, breathing barely noticeable at rest, SaO2 99% on RA, normal breath sounds both lungs, no extra sounds, CXR not performed
Interpret Mr Jones’ CXR
Likely Dx and organisms? Mx?
CXR: hyperinflation (flattened diaphragm), cannot see many lung markings in the lower lung fields (suggests emphysema), no evidence of consolidation
Mrs Jones Dx: likely viral bronchitis (not as unwell, no pre-existing pulmonary or immune compromise)
Mr Jones Dx: S.pneumoniae, M. catarrhalis, H. influenzae
Mrs Jones Mx: none required
Mr Jones Mx: Abx to reduce duration of illness and prevent progression to pneumonia due to COPD (amoxicillin typically used, may include doxycycline if concerned about atypicals), bronchodilator (e.g. salbutamol), corticosteroids (oral or inhaled; probably oral in this context), encourage sputum clearance with chest physio
Mr CAP, 45 year old previously well engineer, presents in winter with acute fever and generalised muscle pain; he is bed-ridden for 3 days
On day 4 he develops sharp R-sided chest pain with cough and yellow sputum
DDx?
Presents with pleuritic chest pain, DDx includes:
Flu with secondary pneumonia
Pleuritis
Pneumothorax (but sputum and cough don’t fit)
Pleural effusion, esp empyema
PE (need to exclude)
Cardiac cause
Mr CAP, 45 year old previously well engineer, presents in winter with acute fever and generalised muscle pain; he is bed-ridden for 3 days
On day 4 he develops sharp R-sided chest pain with cough and yellow sputum
O/E: temp 39, looks unwell, HR 118, BP 110/65, RR 24, SaO2 90% RA, reduced percussion note R lung base, reduced breath sounds R lung base, Hb 15, WBC 18000, Cr 0.12, CK 1800 (i.e. degree of acute renal impairment indicating sepsis)
CXR and sputum MCS performed; interpret the findings
Dx? Likely organism?
What other organisms can cause this type of presentation?
What further Ix might be performed?
Mx?
CXR: R lower lobe consolidation
Sputum MCS: Gram positive diplococci (likely S. pneumoniae)
Dx: community-acquired lobar pneumonia caused by S. pneumoniae
Other causes include typicals (H. influenzae, Klebsiella pneumoniae, M. catarrhalis) and atypicals (Chlamydophilus, Mycoplasma, Legionella)
Further Ix: eGFR, blood culture (before Abx), U/S to look for pleural effusion (empyema will require pleurocentesis)
Mx: hospital admission, supplemental O2, empirical Abx while awaiting results of sputum MCS (amoxicillin/benzylpenicillin + doxycycline/roxithromycin or IV azithromycin, but note this combination may not cover Gram negative bacilli or MRSA - for this you require ceftriaxone and vancomycin)
Mr CAP, 45 year old previously well engineer, presents in winter with acute fever and generalised muscle pain; he is bed-ridden for 3 days
On day 4 he develops sharp R-sided chest pain with cough and yellow sputum
O/E: temp 39, looks unwell, HR 118, BP 110/65, RR 24, SaO2 90% RA, reduced percussion note R lung base, reduced breath sounds R lung base, Hb 15, WBC 18000, Cr 0.12, CK 1800 (i.e. degree of acute renal impairment indicating sepsis)
What further Ix might be performed?
Mx?
Further Ix: eGFR, blood culture (before Abx), U/S to look for pleural effusion (empyema will require pleurocentesis)
Mx: hospital admission (in single room), empirical Abx while awaiting results of sputum MCS (amoxicillin/benzylpenicillin + doxycycline/roxithromycin or IV azithromycin, but note this combination may not cover Gram negative bacilli or MRSA - for this you require ceftriaxone and vancomycin), supportive care (supplemental O2, IVF, analgesia, chest physio for sputum clearance)
Mr CAP, 45 year old previously well engineer, presents in winter with acute fever and generalised muscle pain; he is bed-ridden for 3 days
On day 4 he develops sharp R-sided chest pain with cough and yellow sputum
O/E: temp 39, looks unwell, HR 118, BP 110/65, RR 24, SaO2 90% RA, reduced percussion note R lung base, reduced breath sounds R lung base, Hb 15, WBC 18000, Cr 0.12, CK 1800 (i.e. degree of acute renal impairment indicating sepsis)
What measures are appropriate on admission to ensure infection control?
Single room
Precautions (masks)
Discharge only when afebrile
PCR for flu and other respiratory viruses on nasopharyngeal swab
Can also test urinary Ags for pneumococcus and Legionella (important if you think there is an outbreak)
What tool is used to assess severity of pneumonia in Australia and what are its parameters? What other tool is available?
Pneumonia severity index (PSI)
Takes into account age, sex, nursing home residency, comorbidities, RR, SBP, temp, HR, blood pH, pO2, BUN, Na+, BSL, haematocrit, presence of pleural effusion on CXR
CURB-65 is quicker (takes into account confusion, urea, RR, BP and age >65)
Mrs Spring, 36 year old mother of preschool children, presents with acute fever, exertional dyspnoea and non-productive cough on day 10 post-chemotherapy and high dose prednisolone for newly diagnosed stage 4 HL
Possible sites of infection and DDx?
Sites of infection: alveoli, interstitium, bronchiole (doesn’t fit as well)
DDx: pneumonia (could be viral, opportunistic, fungal pathogens in setting of immunosuppression), metastases, ARDS, chemically-induced pneumonia from chemotherapy
Mrs Spring, 36 year old mother of preschool children, presents with acute fever, exertional dyspnoea and non-productive cough on day 10 post-chemotherapy and high dose prednisolone for newly diagnosed stage 4 HL
O/E: temp 38, looks unwell, HR 120, BP 110/65, RR 28, SaO2 86% on RA, bilateral low-pitched crepitations, loud pulmonary S2 (suggests pulmonary HTN, probably in the setting of hypoxic vasoconstriction), Hb 8.6, WBC 1.2, Cr 0.08, ABG pH 7.49/PaO2 58/PaCO2 30
CXR performed; interpret the findings
Patient has febrile neutropenia!
ABG findings indicate respiratory alkalosis
CXR shows diffuse bilateral patchy infiltrate (suggests multilobar pneumonia, ARDS or cardiogenic cause)
Mrs Spring, 36 year old mother of preschool children, presents with acute fever, exertional dyspnoea and non-productive cough on day 10 post-chemotherapy and high dose prednisolone for newly diagnosed stage 4 HL
O/E: temp 38, looks unwell, HR 120, BP 110/65, RR 28, SaO2 86% on RA, bilateral low-pitched crepitations, loud pulmonary S2 (suggests pulmonary HTN, probably in the setting of hypoxic vasoconstriction), Hb 8.6, WBC 1.2, Cr 0.08, ABG pH 7.49/PaO2 58/PaCO2 30
Ix? Mx?
Ix: sputum MCS (get physios to try and induce sputum, otherwise use invasive test e.g. bronchoscopy), blood cultures, nasopharyngeal swab, urinalysis and urine PCR
Mx: supplemental O2 (may need intubation), isolation (at increased risk due to immunosuppression), Abx (broad spectrum, empirical - follow hospital protocol but consider cefepime and Bactrim to cover PJP), IV fluids
Mr Lim, 24 year old post-grad research student visiting Aus for 12/12, presents with recent onset haemoptysis consisting of bright blood mixed in with cream coloured sputum; has also noted occasional night sweats and a 4kg weight loss over past 1/12
Likely Dx and site of infection?
Classic features of TB (although cough has usually been around for a while), with site of infection most likely in apex
It is likely this is secondary reactivation of a latent (i.e. asymptomatic and non-infectious) TB which was acquired overseas
However, need to exclude cancer
Mr Lim, 24 year old post-grad research student visiting Aus for 12/12, presents with recent onset haemoptysis consisting of bright blood mixed in with cream coloured sputum; has also noted occasional night sweats and a 4kg weight loss over past 1/12
CXR performed; interpret the findings
Focal upper R lobe consolidation with possibility of cavities (likely secondary TB)
Mr Lim, 24 year old post-grad research student visiting Aus for 12/12, presents with recent onset haemoptysis consisting of bright blood mixed in with cream coloured sputum; has also noted occasional night sweats and a 4kg weight loss over past 1/12
Ix?
Mx?
Ix: sputum MCS with acid-fast (ZN) stain, QF-Gold test (IFN y release assay), Mantoux test
Mx: TB is a notifiable disease, initiate standard 4 drug therapy (isoniazid, rifampicin, pyrazinamide, ethambutol/streptomycin) and consider possibility of MDR-TB, treat contacts
Describe the findings of this CXR
Can see cavities, may be TB
