Pneumothorax in ICU

Quick Answer

Quick Answer: Pneumothorax is the presence of air in the pleural space, causing partial or complete lung collapse. In ICU, it commonly occurs as a complication of central venous catheterisation, mechanical ventilation (barotrauma), CPR, or tracheostomy.

TENSION PNEUMOTHORAX is a clinical diagnosis - DO NOT wait for imaging:

• Immediate needle decompression: 2nd intercostal space, mid-clavicular line (or 4th-5th ICS, anterior axillary line)
• Large-bore (14G) needle through chest wall
• Followed by chest drain insertion

Detection in ventilated patients:

• High index of suspicion for any deterioration
• Lung ultrasound: absent lung sliding, lung point sign (100% specific), barcode sign
• CXR: deep sulcus sign on supine film

Chest drain insertion:

• Triangle of safety: 5th ICS, between anterior and mid-axillary lines
• Seldinger technique for simple pneumothorax
• Open technique (blunt dissection) for trauma/haemothorax
• Size: 24-28 Fr for trauma/air leak, 12-16 Fr for simple pneumothorax

ICU Mortality: Tension pneumothorax approaches 100% if untreated; treated pneumothorax mortality relates to underlying condition.

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CICM Exam Focus

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Key Points (10)

Key Points: 1. Tension pneumothorax is a clinical diagnosis - do NOT delay treatment for imaging; immediate needle decompression saves lives [1,2]

2. In ventilated patients, pneumothorax rapidly progresses to tension due to positive pressure ventilation - maintain high index of suspicion for any sudden deterioration [3]

3. Iatrogenic pneumothorax is the most common cause in ICU, occurring in 1-6% of subclavian CVCs and 0.5-1.5% of internal jugular CVCs (reduced with ultrasound guidance) [4,5]

4. Barotrauma occurs in 5-15% of ventilated ARDS patients; risk factors include high peak/plateau pressures, high PEEP, and underlying lung disease [6,7]

5. Lung ultrasound is more sensitive than supine CXR (90-95% vs 50-60%) and can be performed at bedside; absent lung sliding and lung point sign are diagnostic [8,9]

6. Needle decompression is first-line for tension pneumothorax: 2nd ICS MCL (traditional) or 4th-5th ICS AAL (preferred - higher success rate due to thinner chest wall) [10,11]

7. Triangle of safety for chest drain insertion: bounded by anterior border of latissimus dorsi, lateral border of pectoralis major, horizontal line at nipple level, apex of axilla [12]

8. Seldinger technique is preferred for simple pneumothorax (fewer complications, less pain); open technique for trauma, haemothorax, or large air leak [13,14]

9. Persistent air leak (>5-7 days) requires evaluation for bronchopleural fistula, optimisation of ventilator settings (reduce PEEP, reduce tidal volume), and surgical consultation [15,16]

10. Removal criteria: No air leak for 24h, lung expanded on CXR, <200 mL/day drainage, no bubbling on cough; suction can be weaned to water seal before removal [17,18]

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Classification

By Aetiology

By Physiological Impact

By Size (BTS Guidelines) [19,20]

Upright PA CXR:

• Small: <2 cm between lung margin and chest wall at hilum
• Large: ≥2 cm between lung margin and chest wall at hilum

Note: Size estimation on supine CXR is unreliable; CT provides accurate volumetric assessment.

Tension Pneumothorax

Definition: Pneumothorax with one-way valve mechanism causing progressive air accumulation, mediastinal shift, and cardiovascular collapse [2].

Pathognomonic triad (often incomplete):

1. Hypotension (obstructive shock)
2. Absent breath sounds on affected side
3. Tracheal deviation (LATE sign) away from affected side

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Aetiology in ICU

Iatrogenic Causes (Most Common in ICU)

Central Venous Catheterisation

Risk factors for CVC-related pneumothorax [4,21]:

• Multiple needle passes (>3 passes)
• Landmark-guided insertion (vs ultrasound-guided)
• Emergency insertion
• Operator inexperience
• Coagulopathy (haematoma limiting visualisation)
• Obesity or cachexia (anatomical distortion)
• Prior thoracic surgery or radiotherapy
• COPD/emphysema (hyperinflated lungs)

Mechanical Ventilation (Barotrauma)

Incidence: 5-15% in ARDS, 2-5% in general ICU ventilated patients [6,7,22]

Mechanism: Alveolar rupture → air tracks along bronchovascular bundles → mediastinal emphysema → pleural rupture → pneumothorax

Risk factors for barotrauma [23,24]:

• High airway pressures: Peak >40 cmH2O, plateau >30 cmH2O
• High PEEP: Particularly >15 cmH2O without recruitment
• High tidal volume: >8 mL/kg PBW
• Underlying lung disease: ARDS, COPD, asthma, pulmonary fibrosis
• Necrotising pneumonia: Staphylococcus aureus, Klebsiella, Pseudomonas
• COVID-19 ARDS: Higher barotrauma rates (10-20%) reported [25]
• Driving pressure: >15 cmH2O associated with increased risk

Protective ventilation reduces barotrauma risk [26]:

• Tidal volume 6-8 mL/kg PBW
• Plateau pressure <30 cmH2O
• Driving pressure <15 cmH2O
• Appropriate PEEP titration

CPR-Related

Incidence: 1-3% of CPR attempts [27]

Mechanisms:

• Rib fractures with pleural laceration
• Direct lung injury from chest compressions
• Tension pneumothorax as reversible cause (4 Hs and 4 Ts)

Tracheostomy

Incidence: 0.5-2% for percutaneous dilational tracheostomy (PDT) [28]

Mechanism: False passage, posterior tracheal wall injury, paratracheal insertion

Risk factors:

• Difficult anatomy (short neck, obesity)
• Emergency tracheostomy
• Loss of airway during procedure
• High PEEP at time of insertion

Other Iatrogenic Causes

• Thoracentesis/Chest drain: 5-15% (reduced with ultrasound guidance)
• Transbronchial biopsy: 1-6%
• CT-guided lung biopsy: 15-25%
• Nasogastric tube malposition: Rare but catastrophic
• Oesophageal perforation: Rare (endoscopy, dilatation)
• Nerve blocks: Interscalene, supraclavicular blocks
• Pacemaker insertion: Subclavian approach
• Acupuncture: Case reports

Non-Iatrogenic Causes in ICU

Secondary to Underlying Disease

• ARDS: Particularly with high ventilator pressures
• COPD/Asthma: Bullae, air trapping
• Cystic fibrosis: Recurrent, often bilateral
• Pneumonia: Necrotising, especially S. aureus
• Tuberculosis: Cavitation
• Malignancy: Primary or metastatic
• Pulmonary fibrosis: Subpleural cysts

Trauma-Related (Trauma ICU)

• Blunt chest trauma: Rib fractures, lung contusion
• Penetrating trauma: Stab wounds, gunshot wounds
• Blast injury: Barotrauma from pressure wave
• Burns: Circumferential chest burns with lung injury

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Pathophysiology

Normal Pleural Space Physiology

Normal intrapleural pressure: -3 to -5 cmH2O (subatmospheric)

• Maintained by elastic recoil of lung (inward) and chest wall (outward)
• Creates negative pressure that keeps lung expanded
• Normal pleural fluid: 0.1-0.2 mL/kg (lubricating function) [29]

Simple Pneumothorax Pathophysiology

Air entry into pleural space → Loss of negative intrapleural pressure → Lung collapse toward hilum

Physiological consequences:

1. V/Q mismatch: Collapsed lung = shunt physiology
2. Hypoxaemia: Proportional to pneumothorax size
3. Increased work of breathing: Compensatory hyperventilation
4. Limited cardiovascular effect (if not tension)

Air absorption rate: ~1.25% of pneumothorax volume per day on room air; increased to ~4% with supplemental O2 (nitrogen washout effect) [30]

Tension Pneumothorax Pathophysiology [2,31]

One-way valve mechanism: Air enters pleural space during inspiration but cannot escape during expiration

Progressive pathophysiology:

Air entry → Intrapleural pressure rises (exceeds atmospheric)
    ↓
Ipsilateral lung collapse (complete)
    ↓
Mediastinal shift to contralateral side
    ↓
Compression of contralateral lung (bilateral V/Q mismatch)
    ↓
Kinking of great vessels (SVC/IVC, pulmonary veins)
    ↓
Reduced venous return → Reduced cardiac output
    ↓
Obstructive shock → Cardiovascular collapse → Death

Critical points:

• Intrapleural pressure rises to +15 to +20 cmH2O (or higher)
• SVC compression: Elevated JVP, facial plethora
• IVC compression: Reduced preload, hypotension
• Cardiac compression: Reduced diastolic filling
• Death occurs from circulatory failure, not hypoxia

Cardiovascular Effects of Tension Pneumothorax

Positive Pressure Ventilation Acceleration [32]

Why ventilated patients rapidly progress to tension:

1. Positive pressure drives air into pleural space during each breath
2. No spontaneous expiratory pressure gradient to expel air
3. High PEEP maintains elevated intrathoracic pressure
4. One-way valve effect is enhanced by positive pressure
5. Progression to tension occurs within minutes (vs hours in spontaneous breathing)

Clinical implication: ANY pneumothorax in a ventilated patient should be considered a "tension in evolution" and requires immediate drainage.

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Tension Pneumothorax

Immediate Recognition

TENSION PNEUMOTHORAX IS A CLINICAL DIAGNOSIS - DO NOT DELAY FOR IMAGING

Clinical Features

Classic presentation (spontaneously breathing patient):

• Severe respiratory distress
• Tachypnoea, tachycardia
• Hypotension (late)
• Reduced/absent breath sounds (affected side)
• Hyperresonance to percussion (affected side)
• Tracheal deviation (LATE sign - away from affected side)
• Distended neck veins (if not hypovolaemic)
• Cyanosis (late)

Presentation in ventilated patient:

• Sudden hypotension
• Sudden increase in airway pressures (peak AND plateau)
• Difficulty hand-ventilating (high resistance)
• Tachycardia or bradycardia (pre-arrest)
• Falling SpO2
• Cardiac arrest (PEA)

CAUTION: Many classic signs are late or unreliable:

• Tracheal deviation: Present in only ~50% of cases [33]
• JVP elevation: May be absent if hypovolaemic
• Cyanosis: Late sign
• Hyperresonance: Difficult to assess in noisy ICU

Immediate Decompression

Needle Thoracocentesis

Indications [34]:

• Clinical diagnosis of tension pneumothorax
• Cardiac arrest with suspected tension pneumothorax (as part of reversible causes)
• Peri-arrest situation where chest drain cannot be immediately placed

Sites [10,11]:

Technique:

1. Identify landmarks (2nd ICS MCL or 4th-5th ICS AAL)
2. Large-bore IV cannula (14G minimum) - standard cannulae often too short
3. Insert perpendicular to chest wall, just above superior border of rib
4. Advance until "hiss" of air (confirms entry into pleural space)
5. Remove needle, leave cannula in situ
6. Immediate chest drain insertion - needle decompression is a temporising measure only

Limitations [35,36]:

• High failure rate: 30-65% failure with standard 45-50 mm cannulae
• Chest wall thickness: Mean adult chest wall thickness 4-5 cm at 2nd ICS MCL
• Kinking/occlusion: Cannula may kink or obstruct with clot
• Insufficient diameter: Small cannulae cannot keep up with large air leaks
• Temporising only: Always follow with chest drain

Recommended needle length: ≥64 mm (2.5 inches) or use purpose-designed thoracocentesis needle/catheter

Finger Thoracostomy [37]

Alternative to needle decompression in experienced hands:

• Incision in 4th-5th ICS, mid-axillary line (triangle of safety)
• Blunt dissection through intercostal muscles
• Finger sweep into pleural space
• Allows confirmation of lung position
• More definitive decompression than needle
• Proceed directly to chest drain insertion

Immediate Management Algorithm

SUSPECTED TENSION PNEUMOTHORAX
        ↓
CLINICAL DIAGNOSIS (Do NOT wait for imaging)
        ↓
    IMMEDIATE DECOMPRESSION
    - Needle: 14G, 4th-5th ICS AAL (preferred) or 2nd ICS MCL
    - OR finger thoracostomy if experienced
        ↓
    Continue resuscitation/stabilisation
        ↓
    DEFINITIVE CHEST DRAIN INSERTION
    - Triangle of safety
    - Large-bore (24-28 Fr) recommended
        ↓
    CXR to confirm position and lung re-expansion
        ↓
    Continued monitoring and management

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Clinical Features

History

Symptoms:

• Dyspnoea: Sudden onset, severity proportional to size
• Chest pain: Ipsilateral, pleuritic, sharp
• Dry cough: Due to pleural irritation

Key history points:

• Recent procedures (CVC, thoracentesis, biopsy)
• Trauma history
• Underlying lung disease (COPD, CF, previous pneumothorax)
• Current ventilator settings
• Timeline of symptom onset
• Risk factors for barotrauma

Physical Examination

Inspection

• Respiratory distress: Tachypnoea, accessory muscle use
• Asymmetric chest movement: Reduced on affected side
• Tracheal position: Central (simple) or deviated (tension)
• Distended neck veins: Tension pneumothorax
• Subcutaneous emphysema: Indicates air tracking through tissues
• Cyanosis: Late sign of severe hypoxia

Palpation

• Reduced chest expansion: Affected side
• Tracheal deviation: Palpate in sternal notch (late sign in tension)
• Subcutaneous crepitus: Air in subcutaneous tissues

Percussion

Auscultation

• Reduced/absent breath sounds: On affected side
• Increased transmission of heart sounds: On affected side
• Normal contralateral lung: Unless very large or bilateral

Presentation in Ventilated Patients [38]

Challenges in detection:

• Patient often sedated and cannot report symptoms
• Positive pressure ventilation masks some clinical signs
• Background ventilator sounds obscure auscultation
• Signs may develop rapidly (tension within minutes)

High-risk moments in ICU:

• During/immediately after CVC insertion
• After increased ventilator settings (PEEP, VT)
• Post-tracheostomy
• During/after CPR
• After thoracentesis or chest drain removal

Ventilator signs:

• Sudden increase in peak airway pressure
• Sudden increase in plateau pressure
• Reduction in tidal volume (pressure-controlled modes)
• High airway pressure alarms
• Difficulty with manual ventilation (high resistance)

Haemodynamic signs:

• Sudden hypotension (most common presenting feature)
• Tachycardia (or bradycardia if severe)
• Falling SpO2
• Cardiac arrest (PEA most common rhythm)

Red Flag Presentations

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Investigations

Chest X-Ray

Upright PA CXR [39]

Gold standard for stable patients

Findings:

• Visceral pleural line: White line visible, no lung markings peripheral to it
• Absence of lung markings: Beyond pleural edge
• Lung collapse: Toward hilum
• Deep sulcus sign: NOT present (supine finding only)
• Mediastinal shift: Away from pneumothorax (if tension)

Sensitivity: 80-90% for moderate-large pneumothorax

Size estimation (Light Index):

• Small: <2 cm rim at hilum (~15-20% lung volume)
• Large: ≥2 cm rim at hilum (~50%+ lung volume)

Supine CXR [40]

More common in ICU patients - reduced sensitivity (50-60%)

Specific findings:

• Deep sulcus sign: Abnormally deep, lucent costophrenic angle (air rises to most anterior part of hemithorax)
• Hyperlucency of affected hemithorax: Compared to contralateral side
• Sharp cardiomediastinal border: Due to adjacent air
• Double diaphragm sign: Anterior air outlining diaphragm
• Absent lung markings: May be subtle

Pitfalls:

• Skin folds can mimic pneumothorax
• Subcutaneous emphysema can obscure findings
• Small anterior pneumothorax may be invisible on supine film

CT Chest [41,42]

Most sensitive imaging modality (essentially 100% sensitive)

Indications in ICU:

• Confirmation when CXR equivocal
• Assessment of pneumothorax size
• Evaluation for underlying lung disease
• Planning for intervention (loculated collections)
• Trauma CT (routinely detects "occult" pneumothorax)

Findings:

• Air density in pleural space
• Precise volumetric quantification possible
• Identification of blebs, bullae
• Assessment for bronchopleural fistula
• Detection of underlying pathology

Occult pneumothorax: Detected on CT but not visible on CXR (up to 50% of trauma CTs)

• Management: If small and patient not ventilated, may observe
• If ventilated: Lower threshold for chest drain due to tension risk

Lung Ultrasound [8,9,43]

Highly sensitive bedside investigation - superior to supine CXR

Normal Lung Ultrasound Signs

Pneumothorax Ultrasound Signs

Lung Point Sign [44]

Definition: Point on chest wall where normal lung sliding (presence of lung against chest wall) transitions to absent sliding (presence of pneumothorax)

Significance:

• 100% specific for pneumothorax (pathognomonic)
• Indicates extent of pneumothorax
• More lateral lung point = larger pneumothorax
• Absent lung point with no sliding anywhere = complete lung collapse or massive pneumothorax

Ultrasound Technique

1. Linear high-frequency probe (10-12 MHz) or curvilinear (5 MHz)
2. Scan anterior chest (patient supine - air rises anteriorly)
3. Identify pleural line: Between rib shadows
4. Assess for lung sliding: In 2D mode
5. Use M-mode: Seashore (normal) vs barcode (pneumothorax)
6. Search for lung point: Scan laterally from midline

Advantages over CXR:

• Faster (seconds vs minutes for portable CXR)
• More sensitive for supine patients (90-95% vs 50-60%)
• Repeatable at bedside
• No radiation
• Can be performed during resuscitation

Limitations:

• Operator dependent
• Subcutaneous emphysema can limit views
• Cannot quantify size precisely
• Cannot see mediastinum/trachea

Arterial Blood Gas

Findings in pneumothorax:

• Hypoxaemia: PaO2 reduced (proportional to size and underlying lung)
• Respiratory alkalosis: Early compensatory hyperventilation
• Respiratory acidosis: If large/tension causing hypoventilation
• Metabolic acidosis: If tension causing circulatory compromise

ABG role:

• Assess severity of respiratory compromise
• Guide oxygen therapy
• Monitor after intervention

ECG

Potential findings with large left-sided pneumothorax:

• Right axis deviation
• Reduced R wave amplitude in left precordial leads
• Rightward shift of precordial transition zone
• May mimic anterior MI (T wave changes)

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Ventilated Patient Considerations

Detection Challenges [38]

Why pneumothorax is harder to detect in ventilated patients:

1. Patient cannot report symptoms: Sedated, often paralysed
2. Clinical signs are modified:
   • Auscultation difficult with ventilator noise
   • Chest expansion assessment unreliable
   • Positive pressure masks some respiratory signs
3. Rapid progression: Positive pressure accelerates tension
4. Multiple competing causes of deterioration: Sepsis, PE, auto-PEEP, etc.

High Index of Suspicion

Think pneumothorax with ANY sudden deterioration in a ventilated patient:

Clinical triggers:

• Post-procedure (CVC, tracheostomy, thoracentesis)
• After increasing PEEP or tidal volume
• After recruiting manoeuvres
• After prone positioning
• During CPR
• With worsening respiratory failure/escalating ventilation

Ventilator triggers:

• Sudden increase in peak AND plateau pressures
• Sudden decrease in tidal volume (pressure modes)
• Sudden decrease in minute ventilation
• High pressure alarms

Haemodynamic triggers:

• Unexplained hypotension
• Increasing vasopressor requirements
• Tachycardia
• Falling SpO2

Immediate Actions for Suspected Tension

1. Call for help
2. Disconnect from ventilator briefly - if auto-PEEP, patient improves; if tension, no improvement
3. Manual ventilation: Assess compliance (low compliance = possible tension)
4. Auscultate: Compare breath sounds bilaterally
5. Bedside ultrasound: If immediately available and skilled operator
6. If high suspicion → Decompress: Don't wait for imaging

Occult Pneumothorax in Ventilated Patients [45]

Occult pneumothorax: Detected on CT but not CXR

Management controversy:

• Non-ventilated patients: May observe small occult pneumothorax
• Ventilated patients: Lower threshold for drainage due to:
  • Risk of progression to tension
  • Positive pressure drives air entry
  • Patient cannot report symptoms

EAST guidelines suggest observing ventilated patients with occult pneumothorax <1.5 cm, but this requires close monitoring and is controversial [46].

Barotrauma Prevention

Lung-protective ventilation [26]:

• Tidal volume 6-8 mL/kg PBW
• Plateau pressure <30 cmH2O
• Driving pressure <15 cmH2O
• Appropriate PEEP (balance recruitment vs overdistension)
• Avoid auto-PEEP

Monitor for early signs:

• Subcutaneous emphysema
• Pneumomediastinum on CXR (often precedes pneumothorax)
• Rising airway pressures

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Management Options

Overview of Management Strategies

BTS Guidelines Algorithm (adapted for ICU) [19]

Standard BTS algorithm is designed for ED/ward settings. In ICU:

Key modifications:

1. Ventilated patients: ALL pneumothoraces require chest drain (not observation)
2. Low threshold for large-bore drain: Given frequent need for suction, air leak
3. Ultrasound-guided insertion: Recommended when feasible
4. Lower threshold for surgical referral: Persistent air leak in ICU setting

Conservative Management

Rarely appropriate in ICU due to:

• Most patients are ventilated (high tension risk)
• Often iatrogenic with ongoing air leak
• Underlying lung disease common
• Risk of rapid deterioration

If conservative management considered:

• Small pneumothorax (<2 cm) in non-ventilated patient
• No respiratory distress
• Supplemental oxygen (accelerates absorption)
• Close monitoring (repeat CXR at 4-6 hours)
• If requiring mechanical ventilation: Insert chest drain

Needle Aspiration

BTS recommends as first-line for primary spontaneous pneumothorax in ED setting [19].

In ICU:

• Rarely used as definitive management
• Most ICU patients require chest drain due to:
  • Positive pressure ventilation
  • Underlying lung disease
  • Large air leak
  • Need for ongoing drainage

Technique:

• 16-18G cannula, 2nd ICS MCL
• Three-way tap, 50 mL syringe
• Aspirate air until resistance or patient coughs
• CXR to assess success
• If >2.5 L aspirated without resolution → chest drain

Chest Drain Insertion

The definitive management for most ICU pneumothorax - see detailed sections below.

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Needle Decompression

Indications

• Tension pneumothorax (clinical diagnosis)
• Peri-arrest with suspected tension
• Cardiac arrest - bilateral decompression if tension considered
• Temporising measure when chest drain insertion will be delayed

Anatomical Landmarks

2nd Intercostal Space, Mid-Clavicular Line (Traditional Site)

Landmarks:

• 2nd ICS: Space below 2nd rib (2nd rib articulates with manubriosternal joint - angle of Louis)
• Mid-clavicular line: Midpoint of clavicle, usually ~8-10 cm from midline

Technique:

• Identify angle of Louis → count down to 2nd rib → space below is 2nd ICS
• Perpendicular needle insertion just above 3rd rib (avoid intercostal NV bundle below rib)

Concerns with 2nd ICS MCL [10,36]:

• Chest wall thickness: Mean 4.5 cm in adults (up to 6-8 cm in obese patients)
• Standard 45-50 mm cannulae fail in 30-65% of cases
• Internal mammary artery lies ~3 cm from sternal edge (medial puncture risk)

4th-5th Intercostal Space, Anterior Axillary Line (Preferred) [11]

Landmarks:

• 4th-5th ICS: At or slightly above nipple level (male), inframammary fold (female)
• Anterior axillary line: Anterior border of axillary fold

Advantages:

• Thinner chest wall (~3 cm mean thickness)
• Higher success rate (85-90%)
• Same location as definitive chest drain (triangle of safety)
• No risk to internal mammary artery

This is now the preferred site per recent ATLS guidance and military protocols.

Technique

1. Confirm clinical diagnosis of tension pneumothorax
2. Identify landmarks: 4th-5th ICS AAL (preferred) or 2nd ICS MCL
3. Prepare equipment: 14G cannula (≥64 mm length if available), or purpose-designed thoracocentesis catheter
4. Aseptic technique if time permits (not essential in peri-arrest)
5. Insert needle perpendicular to chest wall, just superior to the rib (avoid intercostal neurovascular bundle below rib)
6. Advance until "hiss" of escaping air confirms pleural space entry
7. Remove needle, leave cannula in situ
8. Proceed immediately to chest drain insertion - needle decompression is temporary only
9. Secure cannula if drain insertion delayed (tape, covered with finger of glove as flutter valve)

Equipment

Standard IV cannula limitations:

• 14G × 45 mm: Most commonly available, but often too short
• 14G × 64 mm: Preferred length, less commonly available
• Failure rate 30-65% with standard cannulae [35]

Purpose-designed devices:

• Asherman Chest Seal with decompression needle
• Military-spec thoracocentesis needles (≥80 mm)
• Commercial thoracocentesis catheters

Complications

• Failure to decompress: Needle too short, incorrect site
• Lung injury: Laceration if needle advanced too far
• Bleeding: Intercostal vessels, internal mammary artery
• Infection: If cannula left in situ prolonged period
• Recurrence: Cannula occlusion or dislodgement

Critical Points

1. Needle decompression is a temporising measure only - always follow with chest drain
2. Standard cannulae fail in up to 50% of cases - use longest available
3. 4th-5th ICS AAL is preferred site - thinner chest wall, higher success
4. Don't wait for imaging if tension is clinically suspected
5. In cardiac arrest, bilateral decompression may be indicated if tension suspected

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Chest Drain Insertion

Indications in ICU

Absolute indications:

• Tension pneumothorax (post-decompression)
• Any pneumothorax in ventilated patient
• Large pneumothorax (≥2 cm or symptomatic)
• Haemothorax
• Bronchopleural fistula
• Failed needle aspiration

Relative indications:

• Small pneumothorax in patient likely to require ventilation
• Bilateral pneumothoraces
• Associated haemothorax (even small)
• Underlying lung disease (secondary spontaneous)
• Need for positive pressure ventilation

Triangle of Safety [12,47]

Anatomical boundaries:

• Anterior: Lateral border of pectoralis major
• Posterior: Anterior border of latissimus dorsi
• Inferior: Horizontal line at level of nipple (approximately 5th ICS)
• Superior: Apex of axilla

Target insertion point: 4th-5th intercostal space, mid-axillary line (or between anterior and mid-axillary lines)

Safe zone rationale:

• Avoids breast tissue (cosmesis, breast feeding)
• Avoids muscle mass (pain, poor tract)
• Avoids internal mammary artery
• Avoids major vessels
• Avoids liver/spleen (higher insertion = safer)
• Allows anterior and posterior drainage (mid-thorax position)

Seldinger vs Open Technique [13,14,48]

ICU Recommendations:

• Simple pneumothorax, non-ventilated: Seldinger (12-16 Fr) acceptable
• Ventilated patient: Larger drain (20-28 Fr) preferred due to potential air leak
• Trauma/haemothorax: Open technique, large-bore (28-32 Fr)
• VATS/thoracotomy: As per surgical team

Drain Sizes

Open Technique (Blunt Dissection)

Equipment:

• Chest drain kit (tray, drapes, antiseptic)
• Local anaesthetic (lignocaine 1-2%, max 3 mg/kg)
• Scalpel (No. 10 or 11 blade)
• Artery forceps (curved, large)
• Chest drain (appropriate size)
• Underwater seal drainage system
• Suture material (0 or 1 silk)
• Sterile dressings

Procedure:

1. Positioning: Supine with arm abducted (hand behind head) or lateral decubitus
2. Mark landmark: 4th-5th ICS, mid-axillary line (triangle of safety)
3. Aseptic preparation: Wide antiseptic preparation, sterile drapes
4. Local anaesthesia:
   • Skin wheal
   • Track to pleura including periosteum of rib
   • Into pleura (aspirate first to confirm air/fluid)
5. Incision: 2-3 cm transverse incision, one interspace below intended entry point
6. Blunt dissection:
   • Curve artery forceps over superior border of rib
   • Dissect through intercostal muscles
   • Push through parietal pleura (definite "give")
7. Finger sweep:
   • Insert gloved finger into pleural space
   • Confirm lung/space, sweep to clear adhesions
   • Exclude abdominal viscera (in lower insertions)
8. Insert drain:
   • Mount on artery forceps (curved tip)
   • Guide along finger/forceps track
   • Direct apically (pneumothorax) or basally (effusion)
   • Ensure all side holes are within thorax
9. Connect: To underwater seal drainage system
10. Secure:
    • Horizontal mattress suture through skin (closing incision)
    • Purse-string or stay suture NOT recommended (poor scarring, complications)
    • Anchoring suture around drain
11. Dressing: Occlusive dressing, tape drain securely
12. CXR: Confirm position, lung re-expansion

Seldinger Technique

Equipment:

• Commercial Seldinger chest drain kit (e.g., Rocket, Cook)
• Local anaesthetic
• Scalpel (No. 11 blade)
• Syringe (10-20 mL)
• Guidewire
• Dilators (sequential sizes)
• Pigtail or straight drain

Procedure:

1. Positioning and preparation: As per open technique
2. Local anaesthesia: Track to pleura
3. Needle insertion:
   • Syringe with saline
   • Advance while aspirating
   • Air bubbles = pleural space entry
4. Guidewire:
   • Pass through needle into pleural space
   • Remove needle over wire (maintain wire position)
5. Small incision: Scalpel nick at wire entry point
6. Dilation:
   • Sequential dilators over wire
   • Rotate and advance to create track
7. Insert drain: Over wire into pleural space
8. Remove wire and introducer: Leave drain in situ
9. Connect, secure, CXR: As per open technique

Ultrasound Guidance [49]

Benefits:

• Confirm pneumothorax/effusion location
• Identify safe insertion point
• Avoid intercostal vessels (high-frequency probe)
• Reduce complications
• Confirm drain position in real-time

Technique:

• Mark site of maximum air/fluid
• Identify intercostal vessels
• Real-time guidance during insertion (if skilled)
• Post-insertion confirmation

Complications of Chest Drain Insertion [50,51]

Post-Insertion Care

1. Immediate CXR: Confirm position, lung expansion
2. Connect to drainage system: Underwater seal (initially)
3. Monitor: Drainage volume, air leak, patient status
4. Pain management: Adequate analgesia (systemic ± intercostal block)
5. Mobilisation: Encourage early mobilisation when stable
6. Daily assessment: Drain function, need for suction, removal criteria

---

Drain Management

Underwater Seal Drainage [52]

Principle: Column of water (2-5 cm) acts as one-way valve - allows air/fluid out but prevents re-entry.

Components:

• Collection chamber: Collects fluid drainage
• Water seal chamber: Contains 2 cm water - bubbles indicate air leak
• Suction chamber: If suction applied (set by water level or regulator)

Observations:

• Swinging (tidaling): Respiratory variation in water level - indicates patent drain and pleural space connection (absent = lung expanded, drain blocked, or dislodged)
• Bubbling: Continuous = active air leak; intermittent = small leak or cough-induced; absent = no air leak or blocked

Suction vs Water Seal [53,54]

Controversy exists regarding routine suction.

Evidence summary:

• VALIDATE trial (2021) [55]: Digital suction vs water seal in spontaneous pneumothorax - no difference in duration of air leak or length of stay
• Cochrane review: Insufficient evidence to recommend routine suction

ICU Practice:

• Initial management: Water seal often sufficient
• Suction indications:
  • Persistent large air leak
  • Failure to re-expand with water seal
  • Post-operative (thoracic surgery)
  • Bronchopleural fistula (careful balance)
• Suction level: -10 to -20 cmH2O (higher levels may worsen air leak)

Digital Drainage Systems [56]

Modern digital systems (e.g., Thopaz, Atrium) provide:

• Objective measurement of air leak (mL/min)
• Digital recording of trends
• Portable/ambulatory drainage
• May reduce chest drain duration

Evidence: Several studies suggest reduced duration of drainage and hospital stay with digital systems [57].

Clamping Chest Drains [58]

Generally NOT recommended due to tension pneumothorax risk.

Exceptions (brief clamping):

• Changing drainage bottle
• Assessment prior to removal (4-6 hours clamp trial - controversial)
• Controlled drainage of large effusions (prevent re-expansion pulmonary oedema)

NEVER clamp if ongoing air leak (bubbling) - tension risk.

Drain Removal Criteria [17,18,59]

Criteria for safe removal:

1. Lung fully expanded on CXR
2. No air leak for ≥12-24 hours (no bubbling)
3. Minimal fluid drainage (<200 mL/day for effusion, <100 mL/day for pneumothorax)
4. Patient clinically stable
5. Not on positive pressure ventilation (or weaned to minimal support)

Pre-removal protocol:

• Some centres perform clamping trial (4-6 hours) with repeat CXR
• Others remove without clamping if criteria met
• No strong evidence for clamping trial

Removal technique:

1. Adequate analgesia
2. Patient semi-recumbent or sitting
3. Ask patient to perform Valsalva manoeuvre or hum (increases intrathoracic pressure)
4. Swift removal during expiration/Valsalva
5. Immediately seal wound (occlusive dressing or purse-string closure)
6. CXR within 2-4 hours post-removal (or immediately if symptomatic)

Persistent Air Leak [15,16,60]

Definition: Ongoing air leak ≥5-7 days after chest drain insertion

Causes:

• Bronchopleural fistula: Connection between bronchus and pleural space
• Alveolar-pleural fistula: Peripheral lung injury
• Drain malposition: Side holes outside thorax (subcutaneous)
• Chest wall air leak: At drain insertion site
• Large bullous disease: Multiple ruptured bullae

Investigation:

• CXR/CT: Assess lung expansion, underlying disease, drain position
• Bronchoscopy: Visualise fistula if suspected

Management:

Conservative:

• Optimise ventilator settings: Reduce tidal volume, reduce PEEP, permissive hypercapnia
• Reduce positive pressure: Consider spontaneous modes, NIV, extubation if possible
• Ensure drain patent and correctly positioned
• Water seal (may reduce leak vs suction in some cases)

Medical:

• Blood patch: Autologous blood instilled via drain (limited evidence)
• Chemical pleurodesis: Talc, doxycycline (if ongoing leak >7-14 days)

Surgical:

• VATS: Bullectomy, pleurodesis, stapled repair
• Thoracotomy: For failed VATS, complex fistulae
• Bronchoscopic: Endobronchial valves, glues (experimental)

Referral to thoracic surgery:

• Persistent air leak >5-7 days
• Large bronchopleural fistula
• Recurrent pneumothorax
• Underlying disease requiring surgery (malignancy, bullous disease)

---

Australian/NZ Context

RFDS and Retrieval Considerations [61]

Royal Flying Doctor Service and aeromedical retrieval present unique challenges:

Altitude physiology:

• Atmospheric pressure decreases with altitude
• Boyle's Law: Gas volume increases as pressure decreases
• At 8,000 ft cabin altitude: ~25% volume increase
• Any pneumothorax will expand during flight

Pre-flight requirements for known pneumothorax:

• Chest drain mandatory before aeromedical retrieval
• Water seal drainage (not suction - altitude changes suction dynamics)
• Heimlich valve if water seal not available
• Drain must be unclamped during flight
• Close monitoring during transport

Considerations:

• Remote communities: Telemedicine guidance for chest drain insertion
• Limited imaging: Clinical diagnosis may be necessary
• Delayed specialist access: May need extended conservative management
• Indigenous health considerations: Language, cultural support

Remote Chest Drain Insertion

Challenges in remote settings:

• Limited equipment availability
• Limited imaging (may have no X-ray)
• Limited operator experience
• Delayed evacuation

Adaptations:

• Heimlich valve instead of underwater seal (portable, simple)
• Telemedicine guidance: Remote specialist supervision
• Simple techniques: Finger thoracostomy may be appropriate temporising measure
• Improvised drainage: Commercial kits preferable but improvisation possible

Equipment recommendations for remote clinics:

• Pre-packaged chest drain kits
• Heimlich valves
• Large-bore cannulae for decompression
• Telemedicine capability

Indigenous Health Considerations

Aboriginal and Torres Strait Islander peoples:

• Higher rates of chronic lung disease (COPD, bronchiectasis) - increased SSP risk
• Higher trauma rates - traumatic pneumothorax more common
• Geographic barriers to tertiary care
• Cultural considerations for consent and communication

Māori health (New Zealand):

• Similar patterns of chronic lung disease
• Whānau involvement in decision-making
• Te Tiriti obligations for culturally safe care

Best practice:

• Aboriginal/Torres Strait Islander Health Workers or Aboriginal Liaison Officers involvement
• Māori Health Workers in NZ
• Extended family involvement in consent/discussions
• Cultural safety training for staff
• Health literacy considerations
• Interpreter services as needed
• Consideration of cultural practices around body/procedures

State Retrieval Services

• NSW: Aeromedical and Medical Retrieval Service (AMRS), NETS (neonatal)
• VIC: Adult Retrieval Victoria (ARV), PIPER (paediatric)
• QLD: Retrieval Services Queensland (RSQ)
• WA: Royal Flying Doctor Service (RFDS)
• SA: MedSTAR
• TAS: Ambulance Tasmania Aeromedical
• NT: CareFlight, RFDS

---

SAQ Practice

SAQ 1: Post-CVC Pneumothorax

Time Allocation: 10 minutes Total Marks: 15

Stem:

A 68-year-old male with community-acquired pneumonia requiring ICU admission for respiratory failure has just had a right internal jugular central venous catheter inserted using ultrasound guidance. Fifteen minutes later, the nurse calls you because of acute deterioration.

Current observations:

• HR: 125 bpm
• BP: 85/50 mmHg (previously 130/80)
• RR: 32/min
• SpO2: 84% on 15 L/min face mask (previously 92%)
• Temperature: 38.2°C

The patient is confused and agitated.

---

Question 1.1 (5 marks)

List five clinical signs you would look for on immediate examination to differentiate tension pneumothorax from other causes of deterioration.

Model Answer:

Other acceptable answers: subcutaneous emphysema, tracheal tug, cyanosis, use of accessory muscles

---

Question 1.2 (5 marks)

The clinical examination reveals absent breath sounds and hyperresonance on the right side with a deviated trachea. Describe your immediate management.

Model Answer:

Immediate Actions (First 1-2 minutes) - 3 marks:

• Call for help (cardiac arrest team/senior support) - 0.5 marks
• High-flow oxygen 100% - 0.5 marks
• Immediate needle decompression:
  • "Site: 4th-5th ICS, anterior axillary line (preferred) OR 2nd ICS MCL - 1 mark"
  • "Equipment: 14G cannula (largest available, ideally ≥64mm) - 0.5 marks"
  • Insert perpendicular to chest wall, just above rib - 0.5 marks

Definitive Management - 2 marks:

• Chest drain insertion (triangle of safety, 5th ICS mid-axillary line) - 1 mark
• Large-bore drain (24-28 Fr) preferred given likely ongoing air leak - 0.5 marks
• Connect to underwater seal drainage - 0.5 marks

Note: CXR NOT required before decompression - tension pneumothorax is a clinical diagnosis

---

Question 1.3 (5 marks)

Following successful chest drain insertion and stabilisation, the patient remains intubated and ventilated. Describe your ongoing management of the chest drain over the next 48 hours.

Model Answer:

Monitoring (2 marks):

• Chest drain observations: swinging, bubbling (air leak), drainage volume - 1 mark
• Serial CXR (post-insertion, then daily) to confirm lung expansion - 0.5 marks
• Clinical assessment: respiratory status, haemodynamics - 0.5 marks

Drainage System Management (1.5 marks):

• Initial water seal drainage (suction not routinely required) - 0.5 marks
• If persistent air leak or failure to expand: apply suction (-10 to -20 cmH2O) - 0.5 marks
• Ensure drain patent, no kinking, appropriate positioning - 0.5 marks

Ventilator Optimisation (1 mark):

• Lung-protective ventilation: Vt 6-8 mL/kg, plateau <30 cmH2O - 0.5 marks
• Minimise airway pressures to reduce air leak - 0.5 marks

Documentation and Follow-up (0.5 marks):

• Document CVC insertion and complication - 0.5 marks
• Consider incident reporting as per hospital policy

---

SAQ 2: Persistent Air Leak in Ventilated ARDS Patient

Time Allocation: 10 minutes Total Marks: 15

Stem:

A 52-year-old female with severe ARDS (P/F ratio 85) secondary to influenza pneumonia is on day 7 of ICU admission. She has a right-sided chest drain inserted on day 3 for pneumothorax associated with barotrauma. Despite treatment, there is persistent bubbling in the underwater seal with each ventilator breath.

Current ventilator settings:

• Mode: Volume Control
• Vt: 360 mL (6 mL/kg PBW)
• RR: 28/min
• PEEP: 14 cmH2O
• FiO2: 0.7
• Peak pressure: 38 cmH2O
• Plateau pressure: 28 cmH2O

CXR: Right chest drain in situ, lung partially expanded, right apical pneumothorax 2 cm.

---

Question 2.1 (5 marks)

List five causes of persistent air leak in this patient and indicate which is most likely.

Model Answer:

Most likely cause in this clinical context = bronchopleural fistula from necrotising pneumonia/ARDS

---

Question 2.2 (5 marks)

Describe your non-surgical strategies to manage this persistent air leak.

Model Answer:

Ventilator Optimisation (2.5 marks):

• Reduce tidal volume further if tolerated (accept permissive hypercapnia) - 0.5 marks
• Reduce PEEP if recruitment allows (balance oxygenation vs leak) - 0.5 marks
• Reduce driving pressure - 0.5 marks
• Consider pressure support or spontaneous modes if able to trigger - 0.5 marks
• High-frequency oscillatory ventilation or ECMO if available (off-load lung) - 0.5 marks

Chest Drain Optimisation (1.5 marks):

• Confirm drain position (CT if needed) - 0.5 marks
• Water seal rather than suction (may reduce leak in some cases) - 0.5 marks
• Consider second drain if loculated collection - 0.5 marks

Other Strategies (1 mark):

• Positioning: Affected side down may reduce leak - 0.5 marks
• Bronchoscopy: Assess for visible fistula, consider endobronchial valve - 0.5 marks

---

Question 2.3 (5 marks)

The air leak persists at day 10. Outline the indications for surgical referral and describe the surgical options available.

Model Answer:

Indications for Surgical Referral (2 marks):

• Persistent air leak >7 days despite optimal conservative management - 1 mark
• Failure of lung to re-expand - 0.5 marks
• Identifiable surgical pathology (large fistula, bullous disease) - 0.5 marks

Surgical Options (3 marks):

---

Hot Case Scenarios

Hot Case 1: Ventilated Patient with Sudden Deterioration

Setting: ICU Bed 4 Duration: 20 minutes (10 min assessment + 10 min discussion) Equipment: Ventilator, monitors, IV pumps, charts, ultrasound machine

---

Actor/Simulator Briefing (Not given to candidate):

Patient Details:

• Age: 55 years
• Gender: Male
• Admission diagnosis: Community-acquired pneumonia, ARDS
• Day of ICU stay: Day 5

History:

• Intubated on day 2 for respiratory failure
• Right IJ CVC inserted yesterday (day 4) for vasopressor administration
• Been stable on current ventilator settings until 30 minutes ago
• Sudden hypotension, rising airway pressures, falling SpO2

Current Observations:

• HR: 128 bpm (up from 85)
• BP: 78/45 mmHg (down from 115/70)
• SpO2: 82% (down from 94%)
• Peak pressure: 48 cmH2O (up from 32)
• Plateau pressure: 38 cmH2O (up from 24)
• Noradrenaline increased to 0.4 mcg/kg/min (from 0.1)

Examination Findings:

• Airway: ETT in situ, position unchanged, cuff checked
• Breathing:
  • Absent breath sounds RIGHT side
  • Hyperresonance RIGHT side
  • "Left lung: Reduced air entry with crackles"
  • "Trachea: Difficult to assess (intubated), possibly deviated left"
  • Subcutaneous emphysema palpable right chest wall
• Circulation: Tachycardic, hypotensive despite vasopressors, cool peripheries
• Disability: RASS -4 (sedated)
• Exposure: No rash, abdomen soft

Charts/Data Available:

• Yesterday's CXR: ETT and CVC in good position, bilateral infiltrates
• No CXR since deterioration
• ABG 2 hours ago: pH 7.38, PaCO2 45, PaO2 78 (FiO2 0.5), lactate 1.2

Current Management:

• Ventilator: VC-CMV, Vt 420 (6 mL/kg), RR 24, PEEP 12, FiO2 0.7
• Infusions: Propofol 150 mg/hr, fentanyl 100 mcg/hr, noradrenaline 0.4 mcg/kg/min, piperacillin-tazobactam
• Fluids: Hartmann's 80 mL/hr

---

Candidate Task:

"You are the ICU registrar. This 55-year-old man was admitted 5 days ago with community-acquired pneumonia and ARDS. He has been stable until 30 minutes ago when he suddenly deteriorated. Please assess the patient and present your findings and management plan to the consultant."

---

Expected Performance:

Assessment Phase (10 minutes) - 15 marks

Immediate Recognition (3 marks):

• Identifies this is a time-critical emergency - 1 mark
• Calls for help immediately - 1 mark
• Considers pneumothorax in differential given sudden deterioration in ventilated patient - 1 mark

History/Chart Review (2 marks):

• Notes recent CVC insertion - 0.5 marks
• Reviews baseline ventilator settings and recent changes - 0.5 marks
• Notes current vasopressor requirements - 0.5 marks
• Notes sudden change from previously stable patient - 0.5 marks

Examination (8 marks):

• Airway (1 mark): Checks ETT position, cuff, no obstruction
• Breathing (3 marks):
  • Systematic auscultation comparing sides - 1 mark
  • Identifies absent breath sounds on right - 1 mark
  • Notes hyperresonance and subcutaneous emphysema - 1 mark
• Circulation (2 marks):
  • Assesses perfusion, notes hypotension despite vasopressors
  • Considers obstructive shock pattern
• Disability (1 mark): Notes sedation level
• Integration (1 mark): Correctly diagnoses tension pneumothorax

One-Minute Summary (2 marks):

"This is a 55-year-old man, day 5 ICU admission with ARDS secondary to community-acquired pneumonia. He has suddenly deteriorated with hypotension, hypoxia, and rising airway pressures. Examination reveals absent breath sounds and hyperresonance on the right with subcutaneous emphysema. This is consistent with a right-sided tension pneumothorax, likely iatrogenic post-CVC insertion yesterday. He is in obstructive shock requiring immediate decompression."

---

Discussion Phase (10 minutes) - 15 marks

Question 1: "What is your immediate management?"

Expected Answer (4 marks):

• Immediate needle decompression right chest - 2 marks
  • 4th-5th ICS anterior axillary line (or 2nd ICS MCL)
  • 14G cannula, largest available
• 100% oxygen - 0.5 marks
• Prepare for chest drain insertion - 1 mark
• Continue resuscitation: IV fluids, optimise vasopressors - 0.5 marks

Question 2: "You perform needle decompression and hear a rush of air. What next?"

Expected Answer (3 marks):

• Chest drain insertion - triangle of safety, 5th ICS mid-axillary line - 1 mark
• Large-bore drain (24-28 Fr) given ventilated patient with likely ongoing air leak - 0.5 marks
• Open technique preferred (finger thoracostomy confirms space) - 0.5 marks
• Connect to underwater seal, assess for ongoing air leak - 0.5 marks
• CXR to confirm position and lung re-expansion - 0.5 marks

Question 3: "How could this pneumothorax have been prevented?"

Expected Answer (3 marks):

• Ultrasound-guided CVC insertion - which was done (reduces but doesn't eliminate risk) - 1 mark
• Post-procedure CXR - should have been performed after CVC insertion - 1 mark
• High index of suspicion - any deterioration post-CVC should prompt consideration of pneumothorax - 0.5 marks
• Operator experience - supervised insertion by experienced operator - 0.5 marks

Question 4: "The family has arrived and are distressed. How would you communicate with them?"

Expected Answer (3 marks):

• Calm, clear communication - explain situation honestly - 1 mark
• Acknowledge gravity - explain this is a serious complication that has been treated - 0.5 marks
• Open disclosure - explain this is a complication of a necessary procedure - 0.5 marks
• Ongoing support - offer social work, pastoral care, regular updates - 0.5 marks
• Documentation - incident reporting as per hospital policy - 0.5 marks

Question 5: "What are the risk factors for barotrauma in this patient's ongoing ventilation?"

Expected Answer (2 marks):

• High peak/plateau pressures - 0.5 marks
• ARDS with poor compliance - 0.5 marks
• Underlying pneumonia - 0.5 marks
• Previous barotrauma (now proven with this pneumothorax) - 0.5 marks

---

Hot Case 2: Chest Drain with Persistent Air Leak

Setting: ICU Bed 8 Duration: 20 minutes Equipment: Ventilator, monitors, chest drain with underwater seal, charts

---

Actor/Simulator Briefing:

Patient Details:

• Age: 38 years
• Gender: Male (Aboriginal Australian)
• Admission diagnosis: Severe COVID-19 pneumonia with ARDS
• Day of ICU stay: Day 12

Key History:

• Intubated day 3, tracheostomy day 10
• Right pneumothorax developed day 6 (barotrauma)
• Chest drain inserted day 6, still in situ
• Persistent air leak - bubbling continuously with ventilator breaths
• Lung never fully re-expanded despite treatment
• Family (mother, partner, 3 children) very involved, asking about prognosis

Current Status:

• Tracheostomy on pressure support ventilation
• FiO2 0.45, PEEP 8, PS 12
• Minimal sedation (RASS 0)
• Chest drain: Continuous bubbling, 50 mL drainage/day

Examination Findings:

• Alert, follows commands, mildly anxious
• Tracheostomy in situ, tolerating pressure support
• Chest: Reduced air entry right with persistent air leak
• CVS: Stable, no vasopressors
• Neuro: Appropriate, can write to communicate

---

Candidate Task:

"This 38-year-old Aboriginal man has been in ICU for 12 days with COVID-19 ARDS. He has a persistent air leak from a right pneumothorax. His family is very involved and concerned. Please assess and discuss your management."

---

Expected Performance:

Assessment Phase - Key Points:

• Systematic assessment despite stable patient
• Review of chest drain: Pattern of leak, drainage, position
• Assessment of lung expansion (CXR review)
• Ventilator assessment: Current settings, potential to reduce pressures
• Communication assessment: Patient alert, can participate in discussions
• Cultural considerations: Aboriginal Health Worker involvement

Discussion Phase - Key Points:

Question 1: "Why hasn't this air leak resolved?"

Expected: Bronchopleural fistula from necrotising COVID pneumonia, high-pressure ventilation maintaining leak, possible drain malposition

Question 2: "What non-surgical options are available?"

Expected: Reduce ventilator support (off PEEP), water seal rather than suction, positioning, bronchoscopic assessment, autologous blood patch

Question 3: "When would you refer for surgery?"

Expected: Persistent leak >7-10 days, failure of lung expansion, MDT discussion including patient wishes

Question 4: "The family wants to know the prognosis. How do you approach this?"

Expected considerations:

• Aboriginal Health Worker involvement for cultural support
• Extended family involvement in decision-making (not just next-of-kin)
• Honest prognostic information with appropriate hope
• COVID-19 ARDS recovery can be prolonged but possible
• Surgical options if needed
• Regular family meetings

Question 5: "What cultural considerations are important for this patient and family?"

Expected:

• Aboriginal Health Liaison Officer involvement
• Extended family involvement in care discussions
• Importance of country/land connection
• Potential need for interpreter (even if English-speaking)
• Respect for cultural practices
• Understanding of kinship relationships

---

Viva Scenarios

Viva 1: Tension Pneumothorax Pathophysiology and Management

Stem: "A 60-year-old man on the ward has just had a subclavian CVC inserted for TPN administration. Ten minutes later, he becomes acutely short of breath with a respiratory rate of 36, SpO2 75%, and blood pressure 70/40 mmHg."

Duration: 12 minutes (2 min reading + 10 min discussion)

---

Examiner-Candidate Dialogue:

Examiner: What is your immediate concern?

Candidate: This is a clinical picture highly suspicious for tension pneumothorax following subclavian line insertion. The combination of acute respiratory distress, hypoxia, and hypotension within minutes of CVC insertion strongly suggests iatrogenic pneumothorax with tension physiology.

Examiner: Explain the pathophysiology of tension pneumothorax.

Candidate: Tension pneumothorax develops when there is a one-way valve mechanism - air enters the pleural space during inspiration but cannot escape during expiration.

The sequence is:

1. Progressive air accumulation in the pleural space
2. Rising intrapleural pressure - exceeds atmospheric pressure (normally -3 to -5 cmH2O)
3. Complete ipsilateral lung collapse
4. Mediastinal shift to the contralateral side
5. Compression of contralateral lung - causing bilateral V/Q mismatch
6. Great vessel kinking - SVC and IVC compression reduces venous return
7. Cardiac compression - impaired diastolic filling
8. Obstructive shock - reduced cardiac output, hypotension
9. Death - from circulatory failure rather than hypoxia

Examiner: What is your immediate action?

Candidate: This is a clinical diagnosis requiring immediate needle decompression without waiting for imaging.

I would:

1. Call for help
2. Administer high-flow oxygen
3. Perform needle decompression at the 4th-5th intercostal space, anterior axillary line (preferred site - thinner chest wall, higher success rate) on the side of CVC insertion - likely the left side for subclavian
4. Use a 14G cannula, ideally ≥64 mm in length
5. Insert perpendicular to chest wall, just above the rib
6. Expect a hiss of escaping air confirming entry into pleural space
7. Leave cannula in situ and immediately prepare for chest drain insertion

Examiner: Why do you prefer the 4th-5th ICS AAL site over the traditional 2nd ICS MCL?

Candidate: The 4th-5th ICS anterior axillary line has several advantages:

1. Thinner chest wall - average ~3 cm vs 4-5 cm at 2nd ICS MCL
2. Higher success rate - 85-90% vs 35-70% at 2nd ICS MCL
3. Same location as the definitive chest drain insertion site (triangle of safety)
4. No risk to internal mammary artery (which lies 3 cm from sternum)
5. Recent ATLS and military protocols now recommend this site

Examiner: What are the limitations of needle decompression?

Candidate: There are several important limitations:

1. High failure rate - 30-65% with standard 45-50 mm cannulae, as chest wall may be thicker than cannula length
2. Temporising measure only - cannula can kink, occlude, or provide inadequate decompression for large air leaks
3. Must be followed by chest drain - needle decompression is a bridge to definitive management
4. Equipment limitations - standard ICU cannulae may be too short; purpose-designed thoracocentesis needles (≥64 mm) are preferable

Examiner: How does positive pressure ventilation affect pneumothorax management?

Candidate: Positive pressure ventilation is critical because it accelerates progression to tension:

1. Each positive pressure breath drives more air into the pleural space
2. There is no negative expiratory pressure gradient to help expel air
3. PEEP maintains elevated intrathoracic pressure continuously
4. Progression from simple to tension can occur within minutes rather than hours

Therefore, any pneumothorax in a ventilated patient should be treated with a chest drain - observation is not appropriate. Even small or "occult" pneumothoraces require low threshold for drainage in ventilated patients.

---

Viva 2: Chest Drain Management and Persistent Air Leak

Stem: "You are asked to review a patient on day 8 post chest drain insertion for a secondary spontaneous pneumothorax. The drain is still bubbling continuously. The patient has severe COPD and is currently on BiPAP."

---

Examiner-Candidate Dialogue:

Examiner: Define a persistent air leak and what causes it.

Candidate: A persistent air leak is defined as ongoing air leak ≥5-7 days after chest drain insertion.

Causes include:

1. Bronchopleural fistula - direct connection between bronchus and pleural space
2. Alveolar-pleural fistula - peripheral lung injury with ongoing air leak
3. Large bullous disease - multiple ruptured bullae (common in COPD)
4. Drain malposition - side holes outside thorax causing false "leak"
5. Chest wall leak - around drain insertion site
6. Positive pressure ventilation - maintaining leak (relevant here with BiPAP)

Given this patient's severe COPD, ruptured bullae with alveolar-pleural fistula is most likely.

Examiner: How would you investigate this?

Candidate: I would investigate with:

1. CXR - assess lung expansion, drain position, underlying lung disease
2. CT chest - better assessment of bullous disease, identify fistula location, confirm drain position
3. Bronchoscopy - if large fistula suspected, may visualise; also allows endobronchial intervention consideration

Examiner: What are your non-surgical management options?

Candidate: Non-surgical options include:

Ventilatory optimization:

• Reduce BiPAP pressures if tolerated (lower IPAP/EPAP)
• Consider switching to nasal high-flow or standard oxygen if oxygenation allows
• Avoid positive pressure if possible

Chest drain optimization:

• Confirm drain position on imaging
• Water seal rather than suction (may reduce leak in some cases, though evidence is limited)
• Ensure adequate drain size for the air leak

Other interventions:

• Autologous blood patch - instil 50-100 mL patient's own blood via drain (limited evidence, low risk)
• Chemical pleurodesis - talc or doxycycline if patient not surgical candidate and persistent leak

Examiner: When would you involve thoracic surgery?

Candidate: I would involve thoracic surgery for:

1. Persistent air leak >7-10 days despite optimal conservative management
2. Failure of lung to re-expand
3. Large, visible bronchopleural fistula on imaging or bronchoscopy
4. Underlying disease requiring surgery - malignancy, extensive bullous disease
5. Recurrent pneumothorax - suggests need for definitive pleurodesis

Examiner: What surgical options are available?

Candidate: Surgical options include:

1. VATS (Video-Assisted Thoracoscopic Surgery) - first-line surgical approach

   • Bullectomy/bleb resection
   • Oversewing of fistula
   • Mechanical or talc pleurodesis
   • Pleural abrasion

2. Thoracotomy - for failed VATS, dense adhesions, complex fistulae

3. Bronchoscopic interventions (less invasive alternatives):

   • Endobronchial valves
   • Biological glues
   • Coils

However, in this patient with severe COPD, surgical risk is significant. MDT discussion including respiratory physicians, thoracic surgery, and anaesthetics is essential before proceeding.

Examiner: The patient declines surgery. What would you do?

Candidate: If the patient declines surgery with capacity to make that decision, I would:

1. Respect their autonomy - document discussion and decision
2. Continue conservative management - optimise non-invasive strategies
3. Consider long-term chest drain with Heimlich valve for ambulatory management
4. Chemical pleurodesis - talc or doxycycline via drain if any evidence of pleural apposition
5. Palliative care involvement - if prognosis is poor and treatment options limited
6. Regular review - patient may change their mind or condition may change