Pneumothorax

So, I’m on a respiratory firm at the moment. ‘Firms’, for anyone that doesn’t know, is basically your team/speciality in hospital. So, I was on a Care of the Elderly firm, before this respiratory firm. If I’m not going into firms tomorrow, it means I’m not going into hospital. First years have lectures. Third years have firms. I thought it was a weird term too when I was a fresher. It sounds so American corporation.

But anyway, resp firm. Resp conditions. Pneumothorax. I was on the ward and right at the end of one of the bays, on opposite beds were two Italian males, completely unrelated to each other and both with pneumothoraces and chest drains- wowza.

My firm partner and I saw one of the patients- he took a history and I performed a respiratory exam. We’re still at the stage in our medical school careers where we prefer to do most things in pairs- if anything screams “third years”, it’s that.


Here is Mario’s history:

PC:  Sharp left-sided upper chest pain, which radiates to the back and is worse on deep inhalation and on exertion, tight chested, unable to take in a full deep breath and coughs when he attempts to do so, SOB

HPC: symptoms started 2 months ago, he was found to have a pneumothorax (3cm), which was treated conservatively (oxygen) and he was discharged. Before he was due to fly, he had an x-ray to check on the pneumothorax and it was back to its original size, requiring him to cancel his flight. The chest pain and SOB increased a few days ago.

PMHx: motor cycle accident 1 year ago- infected right shoulder, adenoid removal and hernia repair as a child

FHx: mother had a severe pneumothorax

DHx: Multivitamins

SHx: non-smoker, 7 units of alcohol/week

Respiratory exam:

-decreased left sided chest expansion

-decreased vocal resonance in the left upper zone

-decreased breath sounds in left upper zone (I might have imagined this)

-percussion- my percussion needs major work but I would have expected hyper-resonance in the left upper zone

CXR: apical pneumothorax- 4 cm

Management: his first pneumothorax was treated conservatively with oxygen to try and speed up resorption of the pneumothorax as Mario was quite anxious about intervention, but it did not resolve and so, second time round aspiration was tried and failed and when I saw him, he had a chest drain in. There is talk of surgery to prevent re-occurrence.


 Pneumothorax

Definition: air in the pleural space, which may occur spontaneously or be secondary to chest trauma. A tension pneumothorax is a rare medical emergency- the pleural tear acts as a one way valve through which air passes only in inspiration (so it just gets bigger and bigger and bigger).

Aetiology/risk factors:

Spontaneous primary pneumothorax– healthy, tall males, 10-30 years (exactly like Mario)- result of rupture of a subpleural bleb (air filled space between lung parenchyma and visceral pleura)

Secondary pneumothorax– associated with underlying lung disease: often COPD, asthma, TB, pneumonia, lung abscess, carcinoma, cystic fibrosis, lung fibrosis, sarcoidosis

-Traumatic pneumothorax- penetrating injury to chest, often iatrogenic (E.g. lung biopsy, positive pressure assisted ventilation, subclavian cannulation)

Tension pneumothorax– rare unless patient is on mechanical ventilation

-R/F-connective tissue disorders (Marfan’s, Ehlers-Danlos)

Epidemiology: incidence of spontaneous pneumothorax- 9 in 100000/year. 4x more common in males.

Symptoms: sudden onset pleuritic pain, increasing SOB

                        patients with asthma or COPD may present with sudden deterioration

Signs: reduced chest expansion, hyper-resonance to percussion, and diminished breath sounds on the affected side.

With a tension pneumothorax, there is also tracheal deviation away from the affected side, severe respiratory distress, tachycardia, hypotension, distended neck veins and cyanosis.

Investigations: standard PA chest X-ray will usually confirm diagnosis

-Simple pneumothorax: visible visceral pleural edge seen as a very thin, sharp white line, no lung markings peripheral to this line, peripheral space is radiolucent (black) compared to adjacent lung, lung may completely collapse

(Smaller, simple pneumothoraces can be subtle. In my early days (last week), every CXR I saw was a pneumothorax because I would see the scapula and think it was the pleural edge. )

Tension pneumothorax: as with simple pneumothorax + lung compression, trachea deviated to contralateral side, heart is shifted to contralateral side, ipsilateral hemidiaphragm depressed

-if pneumothorax suspected but not visible than a lateral view x-ray for extra info

-expiratory film may make small pneumothoraces more prominent

-in patients with severe bullous lung disease, CT scan to differentiate emphysematous bullae from pneumothoraces

-ABG to detect hypoxaemia

Management:

Spontaneous primary pneumothorax:

-if they are breathless and/or there is a >2cm pneumothorax on X-ray they should be aspirated- up to 2.5L can be aspirated (Mario really should have been aspirated the first time round). Then, follow up CXR at 2 hrs and 2 weeks. If this is not the case (not SOB, <2cm), consider discharge.

-if this is unsuccessful, they can be re-aspirated and then if unsuccessful, a chest drain can be inserted. Discharge can be considered if aspiration is successful. Chest drain can be removed 24h after full re-expansion and cessation of air leak.

 

-all patients admitted to hospital should receive high flow oxygen to increase absorption of air from the pleural cavity

Secondary pneumothorax:

-if they are over 50 and breathless and the pneumothorax is >2cm, chest drain should be inserted (miss out the aspiration step)

-if this is not the case (not SOB, < 50, < 2cm), then the pneumothorax should be aspirated. If unsuccessful, insert a chest drain. If successful aspiration admit for 24h.

Tension pneumothorax: medical emergency-maximum oxygen, immediate decompression by needle thoracocentesis (large-bore IV cannula into 2nd intercostal space, mid-clavicular line to relieve pressure). Do not wait for a CXR if suspected.  Then, a chest drain is inserted.

-Specialist advice needed if lung fails to re-expand within 48hrs.

-If bilateral/ recurrent pneumothoraces: consider chemical pleurodesis (visceral and parietal pleura fusion with tetracycline or talc) or surgical pleurectomy (remove some pleura).

-Patients advised to avoid air travel until follow up CXR confirms resolution and avoid diving unless they’ve had bilateral surgical pleurectomy.

Complications:

-Tension pneumothorax → positive pressure build up → mediastinal shift- compressing great veins and heart → cardiorespiratory arrest → DEATH

-Recurrent pneumothoraces

-Bronchopleural fistula

Prognosis: after one spontaneous pneumothorax, at least 20% will have another, frequency increasing with repeated pneumothoraces

References: radiopaedia.org, Kumar & Clark’s, cheese & onion, Rapid Medicine

 

 

 

 

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