Teaching Clinic: 4 patients with cough & fever Flashcards
Patient 1
CC: Fever with cough x 5 days
HPI :
7 d – malaise & myalgia
5 d – fever, cough, with scanty sputum not responding to amoxicillin given by GP
2 d – fever & cough continued, some purulent sputum – abdominal discomfort with nausea and diarrhoea .
PH : ex-smoker, non-alcoholic known diabetes x 15 yrs with good control by oral drugs
What are causative agents associated with diarrhoea?
- Influenza
- Legionella
Sputum may indicate lower respiratory tract infection
Myalgia and malaise is more common with URTI, viral (influenza)
LRTI is more associated with bacterial infection / pyogenic infection
Patient 1
Patients did not respond antibiotics and developed further symptoms. Why?
- Pathogen may be responding to antibiotics due to resistance or it is not a bacteria
- Could be atypical in origin
- Non-compliance to medication
- GI S/S may be due to amoxicillin or part of the picture of this LRTI organism = Diarrhoea (S/E from antibiotics)
- ‘Flu-like’ S/S, not respond to amoxicillin
If viral in origin, there may be abdominal discomfort to begin with (i.e. coronavirus can cause abdominal discomfort first before respiratory Sx)
Patient 1
What RF does this patient have to infection?
Elderly, ex-smoker, DM
Extreme age (children & elderly)
Patient 1
PE: General : temp 40°C central cyanosis +ve mild mental confusion
What may account for these symptoms?
There is fever, may have infection
Central cyanosis means hypoxia
* Mild mental confusions:
◦ Can mean severe (Feature of infection)
◦ Severe hypoxia can lead to confusion
◦ CNS involvement
◦ Electrolyte imbalance
◦ Hypoglycemia due to pre-existing DM (glycaemic disturbance due to infection = sepsis)
◦ High fever may lead to confusion (in children, febrile convulsion)
Patient 1
RS :
* mildly stressed with RR 28/min
* trachea central RUZ – ↓ chest expansion, dull percussion except apex
* bronchial breath sounds with insp crackles
RSV interpretations:
- Tachypnoic
- Respiratory distress;
- Consolidations in RUZ
- Decreased movement in RUZ
Pulmonary consolidation compatible with patient with LRTI (pneumonia)
Patient 1
CVS: PR 110/min, regular
BP 125/80
Abdomen: mild diffuse tenderness, no rebound, no mass felt bowel sound normal
CNS : normal
Pulse Oximetry: SaO2 90% (on nasal cannula 3L O2/min flow)
- CVS: Sinus tachycardia with normal BP
- Soft; Mild diffuse tenderness (no signs of acute abdomen);NO Peritoneal signs
- CNS presentations is normal: NOT associated focal neurological deficits (meningism [Kernig & Brudzinski sign] = implies no meningitis and encephalitis)
- Patient has hypoxia
Patient 1
What is strange about the WBC here?
WBC is abnormally normal!
When WBC is single digit, likely normal (4-11)
- Elderly
- Atypical pneumonia
- Immunocompromised
- Partially treated pneumonia
Patient 1
Why does patient have hypoNa?
- SIADH complicating pneumonia (serum urine osmolality)
- Diarrhoea: usually lose more K than Na
- Malnutrition: Poor oral intake
Patient 1
Why may ALT and AST (parenchymal enzymes) be elevated?
- Drug reaction (liver has to process drugs)
- Reaction to infection (liver doesn’t have to wait for organisms to go to them, they just mount the immunological reaction from the liver)
- Reaction to hypoxia
- Underlying fatty liver disease
Patient 1
What is normal range of PaO2?
PaO2 10-14 kP on room air
PaCO2 4.5-6 kP (CO2 is normal)
Type I hypoxic respiratory failure
- The patient is on oxygen to achieve a PaO2 9.8 kP
- Hypoxemia (not enough oxygen in blood = means that we have measured it from ABG!)
- Hypoxia (not enough oxygen)
Patient 1
What is seen here?
Patchy infiltrates: heterogenecity
Consolidation:
- Dense: solid
- Patchy: heterogenous (areas of aeration / radiolucency)
Patient 1
Why is culture -ve? What other test should we use?
Culture may be negative because:
- Partially treated
- Viral in origin
- Poor technique of patient: saliva only
Urine antigen test: specific, sensitivity, rapid, cheap
- +ve from day 3: several weeks; not affected by Ab
Patient 1
Why does this patient have atypical pneumonia? What are some atypical pathogens?
CNS manifestaions is atypical due to mental confusion.
Atypical:
◦ Chlamydia
◦ Legionella
◦ Mycoplasma
◦ !!! Younger patient sexually active:
◦ Chlamydia, Mycoplasma
Deeper sample: BAL, NPA:
‣ TB PCR
Patient 1
What are the investigations for Legionella pneumonia?
Serum antibody: 4 fold rise in titre
Mycoplasma and chlamydia can be detected by PCR with swap
Legionella is a notifiable disease
Patient 1
Why is patient confused clinically?
High fever
Hypoxemia
Feature of L pneumonia
SIADH with hyponatremia
Exclude: DM related, hypo/hyperglycemia, minor stroke
Patient 1
What are the common organisms for community acquired pneumonia in HK?
TB usually present with chronic lung changes, seldom presents acutely (except for in TB meningitis!!!)
Patient 1
What are the mode of transmission (Legionnaire’s disease)?
Patient 1
When must we be alerted to Legionella pneumonia?
Treated with azithromycin and meropenem
Patient 2
- 35 yr old office clerk .
- Fever with cough with purulent sputum x 2 days
- Scoliosis since adolescence, no surgery
- Seen by a GP, CXR taken, and was asked to go to A & E Dept of QMH immediately
What is seen?
- RML is in front of RLL (overlap)
- On CXR, from the posteroanterior view, it can be difficult to tell which lobe is infected
- Use the ‘silhouette sign’: when 2 structure of similary density are side by side, their borders become undefinable on a plain XR (radiodensity is too similar)
– Since the heart border is still clearly seen, therefore, it is likely to be right lower lobe
Lung should normally be radiolucent as it is fully aerated. Heart is radioopaque, situated in the lower part of the anterior mediastinum (next to RML). Lingula lobe of LUL corresponds to RML.
Patient 2
- Fever with cough with purulent sputum x 2 days Scoliosis since adolescence, no surgery
- Seen by a GP, CXR taken, and was asked to go to A & E Dept of QMH immediately
- Hx of RLL pneumonia 2 months ago Rx in hospital
Why does the patient have recurrent RLL pneumonia ?
Suggestive of aspiration pneumonia
Ask about drinking history
RML and RLL is more common (R bronchus is shorter, wider, and straighter than the L bronchus) = more prone to aspiration
RLL consolidation as clear heart border so the lesion is behind the heart
LLL pneumonia as there is distinct heart border so lesion is behind the heart
LUL pneumonia as is there no distinct cardiac border so lesion on same plane
Patient 2
Which side of the lung is more commonly involved in recurrent aspiration pneumonia?
Right bronchus (shown on the left in the image on this page) is shorter, wider, and straighter than the left bronchus
Left lower lobe pneumonia due to patient’s being unable to change their posture for whatever reason (lying to the left-side most of the time)
Patient 2
RF for repeated espidoes of RLL aspiration pneumonia
Patient 2
Gram -ve coccobacilli cultured. What pathogens must we think of?
Any pathogen that goes through the oropharyngeal cavity = must think of contamination with anaerobes, including bite wounds
Augmentin: broad spectrum +/-
- Metronidazole: specific
- Carbapenams: broad spectrum (Clindamycin): broad spectrum
Patient may also have chemical pneumonitis
Patient 2
Why may radiological resolution lag behind clinical improvement?
- Due to chemical pneumonitis
- No need daily CXR
Patient 3
38 yr old man, unemployed, chronic smoker x 20 yrs admitted for fever & chills + cough & purulent sputum for a week, not responding to amoxicillin given by GP
Multiples ilateral cavitating lesions affecting both upper lobes
Patient 3
PE: General : looks ill and toxic temp 40° C
RS : RR 32/min trachea central diffuse inspiratory crackles
CVS: PR 120/min, regular BP 100/60
Abdomen& CNS : normal
Septic looking
Shock is a physiological state: will have hypotension (sepsis-related hypotension)
Patient 3
- CXR
- CBP with differential, RFT, LFT
- Sputum for Gram stain, culture, and sensitivity
- Blood culture
(Sputum for ova and parasite whenever a parasitic cause for lung abscess is suspected)
Platelet reaction to inflammation: * Low platelet
◦ Platelet clumping
◦ DIC: Platelet due to inflammatory reactions;
◦ More sticky and clot the airway
Platelet is an acute phase reactant = may have thrombocytopenia!
Patient 3
What is seen here?
Gram +ve cocci in clusters: staphylococcus
Patient has got multiple bilateral lung abscess
S. aureus commonly comes from skin (artificially created, i.e. instrumentation which breaches skin barrier, other skin wounds, pressure sores = germs collected to R-side of circulation to the heart & lungs)
Patient 3
What are special considerations for MULTIPLE lung abscesses?
Lung is a filter between the R side and L side of the circulation, filtering the bacteria
S. aureus, Klebsiella pneumophilla and mycobacterium tuberculosis like to form cavitatory lesions in lungs!!!
Patient 3
Aetiology of lung abscess
Patient 3
Patient is an IV drug abuser.
What Ix should we do for this patient?
CT brain: abscesses
USG abd: liver abscess
Echocardiogram: vegetation and infective endocarditis features
Patient 3
What treatment must we give the patient?
Patient 4
38 year old lorry driver, smoker
CC : cough with fever for 2 weeks
HPI :
3 w – malaise, progressive SOB cough, little sputum
2 w – fever Not responded to antibiotics given by his GP
3 d – deteriorating cough & SOB, SOB at rest (rapid deterioration)
PH : chronic smoker and occasional beer drinker no Hx of chronic diseases
Bilateral ground glass opacity affecting bilateral lower zones
Must think of viral pneumonia. (homogenous ground glass)
Bilateral diffuse ground glass opacity on top of hypoxic patient who is young: Pneumocystis pneumonia must be considered!
CBC:
Hb 12.5 g/dL
WBC 5.6 10^9/L (Neu 4.2 Lym 0.6 )
(N : 2.2-6.7 & 1.2-3.4 respectively)
Platelet 80 10^9/L (N : 170 –380 )
WBC is abnormally normal
- Thrombocytopenia
- Lymphopenia!
What Ix should we do if there is lymphopenia?
Thrombocytopenia / Lymphopenia
* CD4+ cells [helper] 180/microL (>900)
* CD8+ cells [killer] 420/microL
* Reversed CD4:8 ratio (Normally CD4 > 900/uL)
* HIV Ab +ve
* CD4+ < 200 = opportunistic infection
PCP is an AIDs-defining condition (unless the patient has underlying illness accounting for immunocompromisation, i.e. organ transplant recipient)
- Bronchoalveolar lavage
- Stained with silver stain
What specimens can we use?
- Cysts of P jiroveci in lung disease (it is a fungi)
- Can use sputum / BAL fluid
Never do lung biopsy (patient is not fit, may cause rupture and cause pneumothorax)
Epidemiology of Pneumocystis pneumonia (PCP)
- Why are patients unable to clear it?
What are the main physiologic changes of PCP? What may CXR show?
Supradiaphragmatic sparing
Diffuse bilateral ground glass opacities with sparing of the diaphragm borders
HIV+
Supra-diaphragmatic sparing
Mild PCP
HIV+
Supra-diaphragmatic sparing
Severe PCP: Diffuse Bilateral GroundGlass Opacities with Sparing of the Diaphragm Borders.
How to Dx PCP?
Dx– Cannot be cultured, hence:
- microscopic demonstration of the characteristic cysts on stained resp specimens (induced sputum, BAL, lung tissue)
- silver staining immunofluorescent staining
How do we treat PCP?
Rx: 21 days co-trimoxazole (TMP-SMX) po/iv ( = i.v. pentamidine) adjunctive steroid for severe PCP with PaO2 < 9 kP Precaution: SMX contraindicated in G6PD
- Must give steroids to dampen down cytokine storm because there is a large number of killing of the PCP by septrin
- Prophylaxis: Septrin
◦ Usually take it 2-3 times a week [Tuesday, Thurs, Sat]
◦有冇試過⽩肺病，預防⽩肺病嘅藥
