Investigations Flashcards
First line (gold standard) investigation for a PE?
CTPA
Note if this cannot be carried out then offer therapeutic anticoagulation in the interim ( Riveroxaban 1st line or LMWH of 1st line is not suitable )
How would you investigate cor pulmonale ?
CXR
Explain what a D-dimer is and What are the indications for a D- dimer?
D- dimer is a protein that is made and released into the blood in response to a blood clot so the test is looking at whether or not a patient has a clotting disorder.
- PE
- DVT
- DIC (Disseminated intravascular coagulation)
Explain how type 1 and type 2 respiratory failure is categorised.
T1RF- (Hypercapnic resp failure)
Low oxygen and normal or low carbon dioxide
T2RF- (Hypoxemic resp failure)
Low oxygen and high carbon dioxide levels in the blood
When would a VQ scan be indicated ?
To assess the likelihood of a PE if contrast or radiation exposure is contraindicated.
contraindications include:
- Pregnancy
- Severe renal disease/ impairment
- Anaphylaxis to contrast
- Those on metformin (needs to be stopped before the CT and held for 48 hrs after)
What is a sweat test used for?
It looks at the amount of chloride in sweat and is indicated in diagnosing CF.
(The skin is soaked in pilocarpine and an electrode is placed on the skin for 5 mins. sweat is collected on both arms. A concentration of >60 mol/L = CF and <40 = unlikely )
note:
it can also be used to diagnose bronchiolitis
What is the most reliable test to diagnose whooping cough (pertussis)?
–> If the cough is of 2 weeks’ duration or less, culture of a nasopharyngeal aspirate or nasopharyngeal/pernasal swabs is recommended for people of all ages.
–>Real-time PCR testing of nasopharyngeal or throat swabs if <3 weeks cough in all age groups
–> If the cough is of more than 2 weeks’ duration, anti-pertussis toxin immunoglobulin G (IgG) serology may be employed in people aged over 17 years. Anti-pertussis toxin IgG detection in oral fluid can be used in children aged 5 to 16 years.
in summary….. A culture of a nasopharyngeal swab from the anterior nasopharynx
Which type of malaria is deadly
Falciparum malaria
With a young patient (<45) presenting with COPD (Emphysema) what is the most common cause?
A1AT (Alpha-1 antitrypsin deficiency-)deficiency (levels of <18mmol/L = deficiency)
What radiological findings may be found in a patient with A1AT deficiency ?
- Bullae (fluid filled sac) at the lung bases
2. Emphysematous changes (Alveolar destruction)
What signs may be found on CXR in pulmonary TB? (3 things)
- Caseating cavitation (mainly in upper lobes)
- Mediastinal or hilar lymphadenopathy,
- Pleural effusions
What kind of conditions does a PCR test diagnose? and what types of symptoms do these conditions have?
Upper respiratory conditions
Sx:
- Cough
- Runny nose
- Sneezing
- Throat pain
- Fever
What is bronchoscopy and when is it indicated? (4 things)
- Bronchoscopy is a procedure that helps HCP look directly into the airways
Indication:
- Lung cancer
- Frank haemoptysis (>100ml)
- Suspected mycobacterial disease (e.g TB)
- Refractory consolidation
What does a positive FeNO test indicate?
Eosinophillic inflammation. A positive test indicates an asthma diagnosis but is not conclusive
Why might a V/Q scan be done over a CTPA in young women?
Because a VQ scan has less radiation
Explain what you are looking for in the ABCDE approach to X-rays.
A - airway: trachea, carina, bronchi and hilum
B- Breathing: lungs filled with air? , pleural space
C- Cardiac: heart size, and heart boarders
D- Diaphragm: shape, costophrenic angles
E Everything else: Bones, tubes, pacemakers etc
What findings might you find on an X-ray of someone with HF? (5 things)
- Blunt costophrenic angles
- Cardiomegaly
- Pleural effusion
- Kerley B lines (lower lobes)
- Venous congestion/ interstitial oedema
What X-ray findings might you find in someone with pulmonary oedema? (3 things)
- Cardiomegaly
- Stag antler sign (larger hilum)
- Bilateral changes
What X-ray findings might be seen in a ptx with a pneumothorax ? (4 things)
- Increased pleural space (linear shadow of the visceral pleura – indicating a collapsed lung)
- No lung markings
- Shifted mediastinum (esp. in tension pneumothorax)
- Absent lung airways/ vessels
What condition would present with honeycombing in the lungs?
Bronchiectasis
What are typical findings on V/Q scan that would indicate a PE?
Normal ventilation with bilateral perfusion defects
Explain needle decompression (needle thoracotomy) and when it would be used.
This is the insertion of a needle into the pleural space and is used to decompress a tension pneumothorax.
A large bore needle is put into the 2nd intercostal space at the mid-clavicular line of the lungs and this allows the trapped air to be released from the lungs
In a blood gas, what would a normal Pa02 in a patient on high flow oxygen indicate?
This is abnormal. You would expect the patients oxygen to be above average
What would a normal pa02 in a hypoxic asthmatic patient indicate?
That the patient is tiring and needs ITU Intervention immediately
What is spirometry ?
A test that measures the lung function.
It does this by measuring the amount of air a patient can expel after maximum inspiration.
What is the difference between obstructive and restrictive lung disease?
Obstructive:
air obstruction resulting from narrowing of bronchioles - often due to excessive contraction of the smooth muscle
Restrictive:
Restrictive lung expansion. The alveoli are often smaller
In spirometry what is meant by VC, FVC and FEV1?
VC
total volume of air expelled after maximum inspiration
FVC
Total volume of air forcibly expelled in 1 breath
FEV1
Amount of air forcibly expelled in 1 second
What are contraindications for spirometry ? (7 things)
- Recent MI in 1 month
- PE
- Recent stroke
- Haemoptysis
- Know thoracic/ cerebral or aortic aneurysms
- Uncontrolled HTN
- Abdominal/ thoracic surgery
On spirometry what FEV1/FVC figure would indicate obstruction?
<0.7
Note:
FEV1- tells us if there’s obstruction (if <0.70)
FVC- tells us if there’s restriction (if <80% predicted)
What are the FEV1 figures that would indicate the level of obstruction ?
FEV1 >80% = mild
FEV1 50-80%= moderate
FEV1 30-50%= severe
FEV1 <30%= v. severe
What is the order of an asthma diagnosis?
- FeNO testing
- Spirometry ** (DIAGNOSTIC TEST)
- Bronchodilator reversibility test (can help confirm diagnosis)
- PEFR (support diagnosis)
Explain what would be seen on a graph of a patient with obstructive and restrictive lung disease
Obstructive-
The patient can get the air out but it will take longer to do so. The spirometry graph will be more narrow rather than curved
restrictive-
The patient will not be able to get all the air out and so the graph will be flattened and lower than normal
Explain the MRC breathlessness scale scoring (5 grades)
Grade 1:
No trouble except on vigorous exercise
Grade 2:
SOB when hurrying or walking up inclines
Grade 3:
Walks slower than age mates due to SOBand has to stop when walking at own pace
Grade 4:
Stops for breath after walking 100m or “few mins” of walking on a normal level
Grade 5:
Too SOB to leave the house. breathless when dressing/ undressing
Talk through the stages of analysing spirometry. (5 steps)
- Look at if the VC or FVC is bigger. (if VC is bigger then look at FEV1 /VC and if FVC is bigger then look at FEV1/FVC ratio)
- Then look for evidence of obstruction. (if the ratio is <0.70 then there’s an obstruction)
- The go back to the FVC (restriction)
you are looking to see if its reduced. so is it <80% - Then look at FEV1 (obstruction)
is it <80%? and grade it (do this by looking at the %pr column) - Look at post bronchodilator results has the ratio (which ever one you started with) returned to normal? – if so by how many ml’s and what %??
What would you see on microscopy of the lungs in a patient with acute severe asthma?
Charcot- Leyden crystals
What is the first line test for someone you suspected to have a PE but they have a Wells score of <4 ?
D- dimer
When is Rivaroxaban not appropriate to use? (6 things)
- Active bleeding
- Recent thrombotic events
- Oesophageal varices
- Prosthetic heart valve
- Recent brain or spinal injury
- Recent intracranial haemorrhage
What is considered a positive FeNO test?
And what is a positive test in those ages 5-16years old?
A test of 40 parts per billion or more
5-16 year olds:
35ppb or more
What is the first line diagnostic test for someone with asthma ?
There are more than 1 but typically:
- Spirometry
- Reversibility bronchodilator test
- FeNO
What diagnostic test is most suitable in those aged 17 when investigation asthma?
FeNO
What diagnostic test is most suitable in those aged 17 when investigation asthma?
FeNO
What advice must you give your patient prior to having a spirometry test? (3 things)
- No Salbutamol 2 hours prior to the test
- No restrictive clothing
- If screening test stop any LABA(Foster) 12 hours before
What test is done to confirm a diagnosis of COPD?
Spirometry
What test might you do if a patient <40 years old is presenting with a COPD type picture and has never smoked or has only smoked for a short amount of time?
Serum Alpha 1- antitrypsin deficiency (AAT)
What does a hyper-resonant chest suggest?
Too much air around your lungs or in the lung tissue itself.
Is heart failure associated with a third heart sound?
Yes
What should you do if someone has a Wells score of 4+ points?
Admit to hospital for a CTPA
Treatment for PE?
- LMWH
2. Thrombolytic therapy MAY be indicated to remove the embolic material from the pulmonary arteries
