Pneumothorax

Exam Cram

• Definition: inappropriate air within the pleural cavity caused by lung perforation, can be spontaneous, traumatic or iatrogenic 

• Presentation: tall thin male, acutely SoB with pleuritic chest pain

• Diagnosis: usually on CXR, tension made clinically

• Management: watch and wait, needle aspiration, chest drain or emergency decompression

Outline

Background

• Pneumothorax literally means air in the thorax and is inappropriate air within the lung lining, compressing the lung, usually from a pleural perforation

• Pneumothoraces are more common in connective tissue disorders (Marfan's Syndrome , Ehlers Danlos syndrome), lung disease and cannabis smoking

Assessment

History:

• Sudden onset shortness of breath, chest pain- pleuritic

• MCQ: young tall thin male, playing football

• Note PMH: smoking, lung disease or connective tissue disorders

Examination:

• Focal chest area:

  • Tender to palpate

  • Absent air entry

  • Hyper-resonant to percussion

• Subcutaneous emphysema- caused by air pockets in subcut tissue, these have the potential to compress the trachea, therefore these patients require chest drain insertion and consideration of HDU

• Tachypnoeic, hypoxia

Investigations

• CXR- loss of lung markings

• CT-T can be useful if existing lung disease or bullae

• D-dimer/ troponin, ECG: unremarkable

• USS can be used in trained (rarely used due to ease of XR)

Diagnosis

Diagnostic criteria: imaging finding on chest XR or CT

Differentials

• Pulmonary embolus: Normal CXR, raised d-dimer

• Musculoskeletal pain: Normal CXR

• Bulla CT required to differentiate

• Pulmonary oedema: Coarse crackles to auscultate, responsive to furosemide, CXR overloaded

Classification: 

• Severity: 

  1. Stable, unstable/ tensioning, tension pneumothorax- see next section

  2. Size- measured at the level of the hilum

• Aetiology

1. Spontaneous

   • • • Primary = no previous lung disease

       • Secondary = existing lung disease

Defined as objective evidence of lung disease on i.e. spirometry > smoking + age. 

2. Traumatic

3. Iatrogenic

Management

Primary Spontaneous Pneumothoraces (PSP)

1. Discharge + OP clinic 2w <2cm

2. Needle aspiration > 2 cm

3. Chest drain Failure of needle aspiration

The BTS has published new guidelines to move towards managing PSPs more conservatively. 

Secondary Spontaneous Pneumothoraces

All secondary pneumothoraces require admission for either:

1. Chest drain > 2cm

2. Needle aspiration 1-2cm

3. High flow oxygen & observation 0-1cm

Secondary pneumothoraces have a higher failure rate and if an air leak is suspected they may require discussion with cardiothoracic for pleurodesis- a procedure that uses glues together the two pleura preventing pneumothoraces from occurring.

Traumatic Pneumothoraces

• Managed by emergency department who will

• Call General Surgery for consideration of 

• A large bore chest drain for trauma

Iatrogenic Pneumothoraces

• Usually can be managed conservatively with observation

Tension Pneumothorax

Background

• Tension pneumothorax is medical emergency that requires emergency decompression

• It is caused by a one way valve from a lung perforation causing the pneumothorax to increase in size

• A cardiac arrest is caused by aortic kinking from compression, stopping the heart from pumping blood past this kink

Assessment

History

Examination

• Trachial deviation, 

• Hypotensive: BP < 90/60

Investigations

Diagnosis

Diagnostic criteria: BP < 90/60 with pneumothorax- clinical diagnosis & requires emergency decompression prior to imaging

Differentials: non tensioning pneumothorax, Pulmonary Embolus, Pneumonia 

Classification

• 'Tension-ing': a term I've come across and like. It describes an unwell patient with a pneumothorax with a normal BP but is tachypnoeic, hypoxic, tiring and declining towards a tension pneumothorax arrest

Management

1. Ask for help- pull emergency buzzer, peri-arrest pager

2. Emergency needle decompression

3. High flow oxygen, nil 

Should you ask for help or emergency needle compress first? Only takes a second to pull the buzzer and this is an unwell patient that you need support for. 

Admission Cycle

Admission Work Up

• History, examination & observations

• Chest XR

• Consider CT-T if significant bulla

• Baseline: FBC, urea & electrolytes, ECG

• Indications for admission: chest drain in situ, oxygen requirement, highly symptomatic

Inpatient reviews

• Usually daily CXR and review of chest drain +/- flushing

• Remove chest drain once:

  • Not draining for 24hrs or 

  • CXR shows adequate resolution

• Repeat CXR 4hrs post removal

• If not drained by around 5 days, consider cardiothoracic consult ? surgical intervention: VATs

Discharge planning

• Discharge once: 

  1. Repeat CXR 4hrs post drain removal shows resolution

  2. Acceptable saturations overnight without oxygen (if been hypoxic)

• Advice on discharge

  2. • • Smoking/ cannabis cessation

       • Risk of re-occurrence significant 10-50% depending upon risk factors

       • Unable to go scuba diving again, unless undergone pleurodesis

       • Unable to fly for 2-6w (follow local trust policy)

       • Traumatic pneumothorax: no contact sport for 4 weeks

• Usually Respiratory OP FU

• Consider connective tissue diagnosis 

  2. • Marfan's Syndrome 

     • Ehlers Danlos syndrome (EDS)  

Med Reg Notes

Definition of secondary lung disease

There is debate at the definition of secondary lung disease and where do you draw the line between primary and secondary. Lets take the example of a smoker who develops and dies from COPD aged 70. At which point in his lifespan does he make the cross over from primary to secondary lung disease. I would state once he has a diagnosis of COPD/ deranged spirometry. In the acute setting it can reasonable to treat as per secondary pneumothorax under suspected diagnosis of COPD to aid quick decision making. 

Movement towards conservative management

The BTS released guidance in 2023 to reflect evidence that many primary spontaneous pneumothoraces (PSP) self heal and don't require intervention. Therefore they have offered a pathway for ambulatory devices and discharge and return guidance. This has currently not made it into the MCQs and this website focuses on the MCQ content. 

% Risk of Pneumothorax  

• Healthy population: 1/10,000 (annual risk)

• COPD: 2/10,000 (annual risk)

• Asthma 2/10,000 (annual risk)

• Cystic Fibrosis 8% (lifetime risk)

• Marfans Syndrome 5% (lifetime risk)

• Ehlers Danlos 15% (point prevalence)

• Birt-Hogg-Dube 30% (point prevalence)

• Tuberous Sclerosis 

  • (LAM subtype):   60% (lifetime risk)

• Alpha 1-tripsin def 4% (point prevalence)

Risk of reoccurrence

• PSP: 30% in 5 years

• Secondary: 40% in 5 years

Familial spontaneous pneumothorax FSP

10% of PSPs have a familial link and are FSPs

Iatrogenic Pneumothoraces

Usually require nil intervention and self heal

Persistent air leak: management after 5 days

Rarely pneumothoraces do not heal. After 3-5d cardio-thoracic should be contacted who can perform a VATS (video assisted thoracoscopy surgery) for pleurectomy and pleural abrasion. These procedures have pneumothorax re-occurrence rates of around 5%. 

References

The British Thoracic Society (BTS) 2010 guideline  (reference 2) was the key document in pneumothorax management. 

1. Gorrochategui, M., 2022. Pneumothorax | Radiology Reference Article | Radiopaedia.org. [online] Radiopaedia.org. Available at: <https://radiopaedia.org/articles/pneumothorax?lang=gb> [Accessed 1 September 2022].

2. MacDuff, A., Arnold, A. and Harvey, J., 2010. Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010. Thorax, 65(Suppl 2), pp.ii18-ii31.

3. Touchsurgery.com. 2022. [online] Available at: <https://www.touchsurgery.com/simulations/pneumothorax-1#:~:text=Patients%20can%20often%20be%20discharged,with%20a%20primary%20care%20doctor.> [Accessed 1 September 2022].

4. https://pmc.ncbi.nlm.nih.gov/articles/PMC6543724/

Written in 2022