Pneumothorax

Pneumothorax

Pneumothorax = Presence of air in the pleural space causing partial or complete collapse of the lung.

Normal pleural pressure is negative relative to atmosphere.

When air enters pleural space:

• Negative pressure is lost
• Lung recoils inward
• Chest wall expands outward
• Ventilation decreases
• Severe cases → hemodynamic compromise

Classification

Symptoms

Occasionally, patients may be asymptomatic.

• Dyspnea-Most common symptom.
• Chest Pain-Usually universal:Sudden—Sharp—Pleuritic—Ipsilateral
• Cough-Usually dry.

Physical Examination

Small Pneumothorax

May be normal.

Large Pneumothorax

Inspection

• Tachypnea
• Respiratory distress

Palpation

• Reduced chest expansion,Subcutaneous crepitus

Percussion

• Hyperresonance

Auscultation

• Decreased breath sounds
• Reduced vocal fremitus

Features Suggesting Tension Pneumothorax

• Respiratory—Severe dyspnea,Hypoxia,Tachypnea
• Hemodynamic—Hypotension—Tachycardia—Shock
• Neck-Distended neck veins
• Examination–Tracheal deviation (late sign),Absent breath sounds

• Ventilator

• Sudden rise in airway pressures
• Difficult bagging
• Sudden hypoxemia

Pneumothorax Presentation in a Mechanically Ventilated Patient

In ICU patients, pneumothorax often presents differently from spontaneously breathing patients. Classical symptoms such as pleuritic chest pain may be absent due to sedation, paralysis, or critical illness. 

• Sudden hypoxemia with increasing FiO₂ requirement.
• Reduced lung/chest wall compliance.

Ventilator Findings

• Volume-controlled ventilation (VCV):
  
  • Increased peak airway pressure (Ppeak)
  • Increased plateau pressure (Pplat)
• Pressure-controlled ventilation (PCV):
  
  • Reduced tidal volume (VT)
  • Worsening ventilation despite unchanged pressure settings
  • Expansion may be slower and less obvious

Chest X-Ray

• Normal can not rule out pneumothorax.
• phase of respiration doesn’t matter.

Never wait for X-ray if tension pneumothorax is suspected clinically.

Size Estimation

BTS(British guidelines-preferred)

Large:>2 cm between lung margin and chest wall at hilum.

ACCP(American guidelines)

Large:≥3 cm apex-to-cupola distance.

Differential Diagnosis of Pneumothorax on Chest X-Ray

Skin Fold

• May appear as a pleural line.
• Lung markings are usually visible beyond the line.
• Confirm with lung ultrasound before chest tube insertion if patient is stable.

Giant Bulla

• Bulla wall is typically convex toward the mediastinum (opposite of pneumothorax).
• Giant bullae may cause mediastinal shift and mimic tension pneumothorax.

Left Upper Lobe Collapse

• Edge of collapsed lobe may simulate a pleural line.
• Associated findings:
  
  • Tracheal shift toward the left
  • Mediastinal shift toward the left
  • Elevated left hemidiaphragm
  • Juxtaphrenic peak sign
  • Silhouetting of the left heart border
  • Luftsichel sign (crescentic lucency around the aortic arch)

POCUS

Sensitivity:90%.Better than portable CXR

CT Chest

Gold standard.

Useful for:

• Occult pneumothorax
• Bullous disease
• Trauma
• Persistent air leak

Not needed routinely. 

Management (BTS 2023 guidelines )

Step 1: Is the Patient Symptomatic?

No (Asymptomatic or Minimally Symptomatic)

➡ Conservative Management

PSP(primary spontaneous pneumothorax)

• Outpatient management
• Review every 2–4 days
• Follow-up CXR
• OPD review in 2–4 weeks

SSP(secondary spontaneous pneumothorax)

• Usually inpatient observation
• Closer monitoring because deterioration may occur rapidly

Step 2: If Symptomatic → Look for High-Risk Characteristics

High-Risk Features

Step 3: Is It Safe to Intervene?

Before aspiration or drain:

Pneumothorax must be large enough

BTS practical definition:

If too small:

• CT imaging
• Reassess
• Conservative treatment

Step 4: Choose Management Based on Patient Priority

This is the unique BTS 2023 concept.

Rather than forcing one treatment, BTS allows shared decision-making.

Option 1: Procedure Avoidance

Patient wants:

• No invasive procedure
• Symptoms tolerable
• Clinically stable

Management➡ Conservative care

Suitable for:

• Many PSPs
• Selected SSPs

Option 2: Rapid Symptom Relief With Ambulatory Treatment

Patient wants:

• Early discharge
• Avoid admission

Management ➡ Ambulatory device

Usually:

• Small-bore catheter (8 Fr)
• Heimlich valve

Follow-up:

• Every 2–3 days
• Remove when resolved

BTS Preference

For stable PSPs with available expertise:
Ambulatory management is often preferred over routine chest tube admission.

Option 3: Rapid Symptom Relief (Short-Term Drainage)

Needle Aspiration

Traditionally first-line for PSP.

Success Criteria

Both:

• Symptom improvement
• Sustained radiographic improvement

If Successful

• Discharge
• Follow-up 2–4 weeks

If Failed➡ Chest drain

When Direct Chest Drain Is Preferred

• High-Risk Patients

• Significant hypoxia
• SSP
• Bilateral pneumothorax
• Hemopneumothorax
• Persistent symptoms

• Failed aspiration
• Large pneumothorax with marked symptoms
• Tension pneumothorax

Chest Drain Pathway

Tube

Preferred:Small-bore drain (≤14 Fr)

Avoid routine large-bore drains.

Follow-Up

• Daily inpatient review
• Monitor air leak
• Repeat CXR

Remove Drain When

Both present:

1. Lung re-expanded

2. Air leak ceased

Discharge

After:

• Clinical stability
• Radiographic improvement

Follow-up:2–4 weeks

Traumatic pneumothorax (non-iatrogenic)

• When is a chest tube indicated?
  
  • Observation with serial imaging is often sufficient (with escalation to drainage if the pneumothorax expands or is causing symptoms).
  • Potential indications for chest tube insertion:
    
    • Expansion of the pneumothorax over time.
    • Clinical effects of the pneumothorax (e.g., dyspnea, hypoxemia).
    • Pneumothorax occupying >20% of the thoracic volume

Traumatic pneumothorax (including iatrogenic)

Generally  a conservative strategy is  adequate (e.g., serial observation). But Management can be escalated as per patient situation.

Post-procedure pneumothorax

• Overall, this may resemble the management of primary spontaneous pneumothorax.

Mechanical Ventilation Associated Pneumothorax

• Any pneumothorax occurring during:Mechanical ventilation,NIV,CPAP Should usually receive chest drainage.
• Because positive pressure may convert it to tension pneumothorax.

Oxygen Therapy

Why Oxygen Helps?

Air in the pleural space is mostly nitrogen.

Giving supplemental oxygen:

• Increases alveolar oxygen concentration
• Reduces alveolar nitrogen concentration
• Creates a nitrogen gradient
• Accelerates pleural air absorption

This is called nitrogen washout.

BTS 2023 does not recommend routine high-concentration oxygen simply to hasten pneumothorax resolution.

Reason:

• Evidence quality is low
• Benefit is uncertain
• Oxygen itself may cause harm

Tension Pneumothorax

• Immediate Management
• Do NOT Wait For Imaging
• It is a Clinical diagnosis.

Step 1

Needle decompression

Preferred sites:

4th–5th ICS

Anterior-to-mid axillary line

Preferred in modern trauma/critical care guidelines.

OR

2nd ICS Midclavicular Line

Alternative.

Step 2

Definitive tube thoracostomy

Immediately after decompression.

Persistent Air Leak (PAL)

Usually:Air leak persisting beyond 5 days

Common causes:

• COPD
• Bronchopleural fistula
• Mechanical ventilation
• Necrotizing infection

Management

Early thoracic surgery discussion

Options:

• VATS bullectomy
• Pleurodesis
• Pleurectomy
• Autologous blood pleurodesis
• Endobronchial valves (non-surgical candidates)

Tension Pneumothorax

• Immediate Management
• Do NOT Wait For Imaging
• Clinical diagnosis(Severe Respiratory Distress +Unilateral Absent Breath Sounds +Hypotension)
• Tracheal Deviation(Late finding-Absence does NOT exclude tension pneumothorax.)
• Elevated JVP(Due to impaired venous return.)

Step 1

Needle decompression(14 G-8 cm preferred)

Preferred sites:

4th–5th ICS mid axillary line

Preferred in modern trauma/critical care guidelines.

Step 2

Definitive tube thoracostomy(chest tube-24-28 French)

Immediately after decompression.

If patient ventilated:

Immediately

Reduce:

• PEEP
• Plateau pressure
• Driving pressure

After decompression.

Differential Diagnosis

Pigtail Catheter vs Intercostal Chest Drain (ICD) in Pneumothorax

Re-Expansion Pulmonary Edema(REPE)

Rarely Non-cardiogenic pulmonary edema Occurs after rapid expansion of a chronically collapsed lung.

A patient with pneumothorax may improve initially after chest tube insertion and then develop:

• Sudden hypoxemia
• Cough
• Pink frothy sputum
• Respiratory failure

within a few hours.

This deterioration is often mistaken for:

• Tube malposition
• ARDS
• Aspiration
• Pneumonia

Chest X-Ray

• New alveolar infiltrates develop in the re-expanded lung.
• Usually:Ipsilateral
• Same side as pneumothorax.

Risk factors:

• Large pneumothorax
• 72 hours duration
• Rapid drainage

Pathophysiology

During prolonged lung collapse, pulmonary blood flow decreases due to hypoxic vasoconstriction and compression of the pulmonary microvasculature. When the pneumothorax is rapidly drained and the lung suddenly re-expands, there is abrupt restoration of blood flow (reperfusion) to the previously ischemic lung tissue. This triggers the generation of reactive oxygen species and oxygen free radicals, causing endothelial injury and disruption of the alveolar-capillary barrier. The resulting increase in capillary permeability leads to leakage of protein-rich fluid into the alveoli, producing pulmonary edema similar to ARDS. In addition, rapid re-expansion mechanically stretches the alveolar-capillary membrane, further increasing permeability and edema formation, particularly when the lung has been collapsed for several days.

Treatment:

• Oxygen
• NIV
• Mechanical ventilation if needed

References

1. EMCrit IBCC – Pneumothorax.
2. StatPearls – Pneumothorax.
3. Irwin & Rippe’s Intensive Care Medicine.
4. Oh’s Intensive Care Manual.
5. British Thoracic Society Pleural Disease Guidelines.
6. American College of Chest Physicians (ACCP) Consensus Statement.
7. ATS/STS guidance on spontaneous pneumothorax and pleural disease.