Pneumothorax (PTX)

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), chronic lung disease (COPD, ILD, Lung Cancer, Asthma) and tobacco or cannabis smoking

Assessment

History:

• Sudden onset shortness of breath, chest pain- pleuritic

  • Primary spontaneous pneumothorax: young tall thin male, playing football

• PMH: smoking, lung disease or connective tissue disorders

Examination:

• Focal chest area: 

  • Absent air entry

  • Hyper-resonant to percussion

  • Trachea pushed away from site

• Subcutaneous emphysema- bubble wrap air pockets in subcut tissue (have potential to compress trachea)

• Tachypnoeic, hypoxia, hypotension for tension pneumothorax

Investigations

• CXR- loss of lung markings

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

• D-dimer/ troponin, ECG: nil acute

• 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: 

• Aetiology

1. Spontaneous

2. Traumatic 

3. Iatrogenic

• Severity

  1. Status

     • Tension pneumothorax- BP < 90/60

     • High Risk

       • • Significant hypoxia

         • Bilateral pneumothoraces

         • Underlying Lung Disease

         • > 50 years with significant smoking disease

         • Haemopneumothorax

     • Low Risk

  2. Size- measured at the level of the hilum

  3. Presence of symptoms

Management

All Acute 

• High flow oxygen

Spontaneous Pneumothoraces 

1. Assess severity: size, high risk features, symptomatic

Low Risk

• Discharge with outpatient follow up if:

  • Asymptomatic

  • Symptomatic with insufficient size

• If symptomatic & sufficient size, let patient preferences predominate for:

  • Conservative care

  • Ambulatory device

  • Needle deompression

High Risk but no signs of 'tensioning'

1. Consider CT if CXR not clear on diagnosis or size

2. Chest drain

Traumatic Pneumothoraces

• Managed by emergency department, who will:

• Call General Surgery for consideration of:

• A large bore trauma chest drain

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

Presentation

• Actively deterioating during assessment

• Recent chest drain removed or trauma

Examination

• Trachial deviation, 

• Focal hyper-resonance, absent/ reduced breath sounds, subcut emphysema, reduced expansion

• Hypotensive: BP < 90/60

• Tachpnoeic, hypoxic, tachcardia

Investigations

• Nil - do not wait for portable CXR to decompress

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

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. 

Needle decompression: 

• Grey cannula/ large bore needle into either triangle of safety or 2nd intercostal space midclavicular line; both just above the rib

• In patients with a large BMI, a cannula needle may not be long enough

• Do not use local anaesthetic- medical emergency

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 3-5 days, consider cardiothoracic consult ? surgical intervention: VATs

• Complications

  • Surgical intervention

  • Tension pneumothorax

  • Pneumonia, pulmonary abscess

Surgery

Indications

1. Persistent air leak despite chest drain

2. Recurrent pneumothoraces

Operations

1. Pleurodesis

2. Pleurodectomy

Routes

1. VATS - lower post operative complications but higher pneumothorax relapse rates

2. Open thoracotomy

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%. 

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)  

Deeper Dive

Primary vs Secondary

This is a historical relic of previous BTS guidance and now catergorised as high risk or low risk. The guidance answers the question of at what threshold does age and smoking become presumative of lung disease- > '50 years with significant smoking disease'. Primary used to be used without lung disease and secondary for patients with lung disease. 

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. 

% Risk of Pneumothorax  

Risk of reoccurrence

• PSP: 30% in 5 years

• Secondary: 40% in 5 years

• 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)

Familial spontaneous pneumothorax FSP

10% of PSPs have a familial link and are FSPs

Chest Drain Suction in Pneumothoraces

Very rarely used due to risk of re-expansion pneumothoraces. 

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