Spontaneous Pneumothorax

Objectives

To guide the management of patients presenting to medical facilities with suspected spontaneous pneumothorax.

Scope

These guidelines outline the investigations and management of spontaneous pneumothorax. Clinicians should refer to separate guidelines in the event of traumatic pneumothorax, including iatrogenic pneumothorax as a result of medical intervention.

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a role in a forward medical location or in an emergency department on deployed operations. Accordion content also provides basic guidance on subsequent ward care.

Initial Assessment & Management

In a forward location, if spontaneous pneumothorax is suspected from the history and clinical findings (including point of care ultrasound if available), the patient should ideally be evacuated to a facility where imaging is available.

Pending transfer for imaging:

  • If the patient has life-threatening adverse features including progressive respiratory distress, hypotension (systolic <90mmHg) and worsening hypoxia, treat for tension pneumothorax with needle decompression or thoracostomy.
  • Provide supplementary oxygen if necessary to maintain SpO2 ≥94%. COPD may be rare in the deployed environment but if chronic CO2 retention is suspected, target ≥88%.
  • Give sufficient analgesia to control pain including paracetamol, non-steroidal anti-inflammatories and, if needed, opiates.
  • Point of care ultrasound undertaken by a suitably trained operator may support the diagnosis but should not be used in place of chest x-ray unless no alternative imaging is available.
Minimally symptomatic patients might be able to return to normal duties after a period of observation, but must have radiological confirmation of the diagnosis first. Do not attempt needle aspiration without radiological confirmation.

Remember to consider the key differential diagnosis of pulmonary embolism - both conditions typically present with sudden onset and may feature shortness of breath, pleuritic chest pain and haemodynamic compromise.

Advanced Assessment & Management

Chest x-ray (CXR) should be obtained at the earliest opportunity.

A pneumothorax measured as >2cm between the lung and the chest wall (either at the apex, or horizontally at the level of the hilum) is considered to be sufficiently large to allow safe intervention.

Management of spontaneous pneumothorax depends on the aetiology:

  • Patients with underlying lung disease including COPD, interstitial lung disease or cystic fibrosis (but not asthma) should be considered to have secondary spontaneous pneumothorax.
  • Patients ≥50 years with a significant smoking history (>20 pack years) should also be considered to have secondary spontaneous pneumothorax.
  • All other patients can be treated as having primary spontaneous pneumothorax.

Remember that the aetiology of the pneumothorax and the patient's clinical condition are the main indicators for the most appropriate management strategy - not the apparent size of the pneumothorax.  

 

Primary Spontaneous Pneumothorax (PSP)

High-risk features

Hypoxia, bilateral pneumothorax or haemopneumothorax are indicators for intercostal drain insertion.

Conservative Management

Although current guidance for the civilian context favours conservative management for pneumothorax, associated with a lower risk of recurrence, this may not be appropriate in the military context as the time to resolution is significantly prolonged by a conservative approach (on average 2-4 weeks vs 3-4 days).

Conservative management in the deployed context should only be considered if the patient:

    • is well and able to be ambulatory without getting breathless
    • is expected to be able to avoid strenuous activity
    • has accompanied living arrangements
    • is expected to be able to return immediately to medical care if their condition deteriorates

If seeking to manage conservatively, observe for a minimum of 4 hours in medical facility to ensure no deterioration. If condition does not change, discharge with instructions to return if worsens, then follow up in 5-7 days with repeat imaging. If resolved the patient can be discharged with routine outpatient follow-up on return from operations; if improved but not fully resolved then continue to monitor with clinical and radiological review at intervals of 5-7 days until fully resolved.

If at any review the pneumothorax has persisted without any improvement (no change in size) or has worsened (increasing in size) then escalate to aspiration or intercostal drain insertion.

Needle Aspiration

If conservative management is not appropriate or fails, needle aspiration of air should be attempted following the guidance below. Following the procedure, repeat imaging should be performed and if the pneumothorax has resolved (or almost fully resolved) then the patient can be discharged in accordance with the same guidance and follow up approach used for conservative management.

Ambulatory Drains

Ambulatory management of pneumothorax, with devices that incorporate a one-way valve such as a pleural vent, are not currently recommended in the deployed setting.

Intercostal Drainage

If the patient has or develops any high-risk features, or if needle aspiration is unsuccessful - noting a quoted success rate of approximately 50% - then proceed to chest drain insertion using the relevant guideline (link to follow).

 

Secondary Spontaneous Pneumothorax (SSP)

High-risk features

As for PSP, hypoxia, bilateral pneumothorax or haemopneumothorax are indicators for intercostal drain insertion.

Conservative Management

Conservative management for SSP is rarely appropriate in the deployed context. Consider only if the pneumothorax is <1cm width from its edge to the chest wall (measured horizontally at the level of the hilum) and the patient is minimally symptomatic. In such cases, follow the same approach as detailed for PSP including follow-up arrangements.

Needle Aspiration

Needle aspiration is also likely to be of limited value for SSP in the deployed context. Consider only if the pneumothorax is <2cm width from its edge to the chest wall (measured horizontally at the level of the hilum) and the patient is minimally symptomatic. In such cases, follow the same approach as detailed for PSP.

Intercostal Drainage

For secondary spontaneous pneumothorax, if aspiration has been unsuccessful or if the width of the pneumothorax exceeds 2cm or if the patient is symptomatic then proceed to chest drain insertion using the relevant guideline (link to follow).

Prolonged Casualty Care

If evacuation to a medical facility with imaging capability is delayed, maintain conservative management until the diagnosis is confirmed.

Monitor the patient and be prepared to undertake needle decompression or thoracostomy if signs of tension pneumothorax develop at any point.

Monitor oxygen saturations regularly and provide supplementary oxygen if necessary to maintain SpO2 ≥94%. COPD may be rare in the deployed environment but if chronic CO2 retention is suspected, target ≥88%.

Continue to administer both regular and as-required analgesia to control pain including paracetamol, non-steroidal anti-inflammatories and, if needed, opiates.

Do not discharge the patient with conservative management nor attempt needle aspiration without radiological confirmation of the diagnosis.

Paediatric Considerations

In children age <12 size calculations of pneumothorax may be unreliable, reinforcing the point that the size of a pneumothorax is much less important than the degree of clinical compromise.

Early paediatric specialist advice should be sought.

Intercostal drain management

CXR should always be repeated following insertion of an intercostal drain to confirm correct positioning.

Intercostal drains should be flushed every 6 hours to maintain patency. This should be a 15ml 0.9% normal saline flush to both the patient and drain (total 30ml) via a 3-way tap adhering to aseptic technique using sterile gloves.

Monitoring - Drain dressings and insertion site need regular review for signs of infection. Drain observations should be documented, including drain depth, assessment of surgical emphysema, patient comfort and whether the drain is swinging and/or bubbling.

Infection - Clinicians should be alert to the potential for an underlying lower-respiratory tract infection or the subsequent development of such an infection. If a drain site appears infected then a low threshold should be used for treatment with antibiotics (which should be given in accordance with the antimicrobial guidance - link to follow). If this fails to lead to improvement the drain should be removed and re-sited.  

Movement - If the depth of a drain appears to have changed, repeat imaging (CXR) should be undertaken to confirm placement is still adequate. Do not blindly advance drains after initial insertion. If a drain has withdrawn but is found to still be adequately sited on CXR then it can be fixed at the new depth; if the new position is no longer satisfactory then the drain must be removed and a new drain sited.

Air leak - If there is an air leak leading to the pneumothorax persisting after more than 72 hours then suction may be considered but expert advice should be sought. The suction required is high volume, low pressure (1-2kPa) which necessitates a paediatric adaptor.

Drain removal - the intercostal drain should be removed once CXR confirms resolution of the pneumothorax. However, consideration may be given to administering chemical pleurodesis prior to drain removal, particularly when considering service personnel and the occupational impact of a previous pneumothorax. This will be under the advice and guidance of a respiratory consultant and will only be a consideration when the patient is in definitive care, so early discussion should be initiated if possible.

Needle Aspiration (procedure)

Needle aspiration is performed by inserting a 14-gauge intravenous cannula into either the second intercostal space in the mid clavicular line, or into the 4th intercostal space just anterior to the mid-axillary line on the affected side.

A sterile technique must be used, and local anaesthetic applied. The parietal pleura is especially sensitive, so advancing the local anaesthetic needle until air is aspirated, withdrawing until aspiration ceases (indicating that the needle tip is at the pleural surface), then infiltrating local anaesthetic can greatly improve patient comfort. 

The cannula used for aspiration should be attached to a 3-way tap with a 50ml syringe. The 3-way tap can then be rotated to allow air to be aspirated into the syringe then blown into the environment. Each aspiration should be counted.

Aspiration should be continued until:

  • no more air can be aspirated - may indicate resolution, check with CXR
  • or significant coughing is induced in the patient - may indicate resolution, check with CXR
  • or more than 2 litres (40 syringes) of air has been aspirated - may indicate ongoing air leak

If aspiration has failed to resolve, or an ongoing air leak has been identified, proceed to intercostal drain insertion.

Remember that all patients that have undergone needle aspiration must have a post-procedure chest X-ray to confirm resolution of the pneumothorax.

Flying

Standard civilian advice is that patients who have a spontaneous pneumothorax should not fly until 7 days have elapsed following full resolution of the pneumothorax on CXR. The operational environment may necessitate deviation from this advice.

Patients transported in rotary aircraft do not normally require intervention as flight will be at low altitude.
Patients transported in fixed-wing aircraft should either have an intercostal drain in situ, or as a minimum should be accompanied by a person who is trained and able to decompress the pneumothorax and insert an intercostal drain if needed.

Chest x-ray is required to confirm the diagnosis of pneumothorax prior to intervention (unless managing suspected tension pneumothorax). This means that a patient with suspected pneumothorax who requires fixed-wing evacuation to a facility with medical imaging capabilities will need to be either escorted or retrieved by a suitably trained clinician.

Follow up

All patients with pneumothorax (primary or secondary) should be referred for follow up on return from operations, even if successfully managed conservatively.

Thoracic surgery may be considered for military personnel even after a single primary spontaneous pneumothorax, due to the high risk nature of service occupations, and referral for this would be appropriate.

Cystic lung disease (lymphangioleiomyomatosis (LAM)) or catamenial cause should always be considered in female patients with primary spontaneous pneumothorax. Atypical presentations including possible appearance of cystic lesions on plain film imaging warrants referral to an expert clinician for cross-sectional imaging and assessment.

Last reviewed: 27/02/2026

Next review date: 27/02/2027