PE & pneumothorax Flashcards

1
Q

Pulmonary embolism

A

The blockage of the pulmonary artery or one of its branches by a embolus
usually a venous embolus from the deep leg veins (80%) but can be septic emboli (endocarditis), malignant emboli, fat, air or amniotic fluid.

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1
Q

Risk factors for a PE

A

Post operative or lower limb fracture
Pregnancy, Coagulopathy or previous DVT/PE
Malignancy or Reduced mobility
Oestrogen containing contraceptive pill/HRT
COPD or congestive heart disease

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2
Q

Risk stratification for PE

A

Clinical features + (a) major risk factor OR (b) absence of other cause –> if both high risk, if one intermediate, if neither then low
For high risk proceed directly to CTPA, low and intermediate then D-dimers, and if +ve proceed to CTPA

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3
Q

Pneumothorax

A

An abnormal collection of air in the pleural space which may interfere with normal breathing
Different types can occur and have different treatment
If symptomatic a chest drain can be placed underwater to assist the lung in re-inflating or a pleurodesis can be performed

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4
Q

Types of pneumothorax

A

A primary has no apparent cause, while a secondary occurs in the presence of an existing lung pathology
Simple/open–> open route from outside to the pleural space
Closed–> a fixed, closed volume of air in the pleural space
Tension–> a 1-way valve such leading to increasing pressure

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5
Q

Tension pneumothorax

A

When a 1-way valve which leads to increasing pressure in the pleural space which leads to mediastinal shift and death
This will present with chest pain and respiratory distress, leading to tachycardia, tachypnoea and hypotension, hypoxia and tracheal deviation away from the affected side

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6
Q

Treatment of a tension pneumothorax

A

Emergency
Large bore cannulae into 2nd intercostal space at midclavicular line
Insert chest drain

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7
Q

Treatment of pneumothorax

A

A pneumothorax showing a radiological rim of 2cm, the patient >50yrs or it hasn’t responded to aspiration then a chest drain should be placed.
Otherwise discharge w/outpatient X-ray

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8
Q

Radiological appearance of pneumothorax

A

Can be small and hard to spot
Check if the lung markings extend fully to the margin
A 2cm rim on an CXR occupies 49% of the hemithorax

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9
Q

Risk factors for spontaneous pneumothorax

A
Being a tall thin young man
Lung pathology such as COPD or lung cancer 
Smoking, and particularly cannabis
Family history 
Previous pneumothorax
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11
Q

Treatment of PE

A
Emergency
Give O2 
Consider 50mg bolus alteplase
LMWH heparin (tinzaparin 175u/kg/24h SC)
Stabilise patient (? Fluid challenge) and commence warfarin
INR 2-3 (3.5 if recurrent) for 3mo
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12
Q

Symptoms of PE

A

Vary depending on if it is an acute massive, small or medium or chronic PE. Generally include:
SOB, pleuritic chest pain,haemoptysis, palpitations, tachycardia and tachypnoea eventually leading to hypotension and death

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13
Q

Incidence of VTE

A

Unknown in the community but 1% of all hospital admission and causes 5% of in hospital deaths - particularly in patients with stroke, cancer or pregnancy

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14
Q

Acute Massive PE

A

Significant reduction in CO causing right HF leading to severe dyspnoea, collapse and crushing chest pain.
Signs: shock, tachycardia, RV gallop rhythm, loud P2, S1Q3T3 (or ant T-wave inversion or RBBB)
Differentials: MI, pericardial tamponade and aortic dissection

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15
Q

Small to Medium PE

A

Segmental artery occluded leading to infarction (+effusion) causing pleuritic pain, restricted breathing & haemoptysis.
Signs: low fever, effusion, creps, pleural rub, tachycardia and raised hemidiaphragm. No specific ECG changes,
Differential: pneumothorax, pnuemonia or MS chest pain

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16
Q

Chronic PE

A

Chronic blockage of pulmonary microvasculature leading to right HF causing exertional dyspnoea and late symptoms of pulmonary hypertension or HF
Signs: RV heave and loud P2 in late disease, signs of HF in end stage. CXR may show enlarged pulmonary trunk, heart or right ventricle.
Differential: pulmonary hypertension from other causes

17
Q

Role of D-Dimers in diagnosing PE

A

Useful as a negative predictor – low D-Dimers broadly rule out PE (if high risk second line investigations may be necessary to exclude PE).
Raised D-Dimer in high risk pts are sufficient for a provisional diagnosis but in low risk pts further test are still needed

18
Q

ECG changes in PE

A

Generally –> non-specific sinus tachycardia or anterior T-wave inversion
In large PEs Right heart strain can produce S1Q3T3 pattern and the appearance of RBBB.

19
Q

Definitive diagnostic tests for PE

A

CT pulmonary angiography is first line
VQ scans are now rarely used except in special cases (pregnancy - can shield the fetus)
Doppler scans are useful to identify clots in limbs.
Echos can be used to assess heart damage.

20
Q

Management of PE

A

Treatment of hypoxia and shock are most important (inotropes are of limited use as the heart is near maximal distension, and diuretics and vasodilators should also be avoided) - external cardiac massage can be useful in extreme cases.
Mainstay of treatment is anticoagulation

21
Q

Anti coagulation in PE

A

At least five days of LMWH - reduces clot growth, embolisation and mortality
After this Warfarin should be started to maintain INR for as long as necessary – 3months for reversable risk or life if permanent RFs or repeated thrombous. (also longer in men)