Needle Decompression

JRCALC 2024 · Large Bore Cannula · Prehospital

⚡ TENSION PNEUMOTHORAX — DECOMPRESS NOW

Needle Decompression

Large bore cannula · Both routes · Prehospital reference

⚠ Life-Threatening Emergency Tension pneumothorax is a clinical diagnosis. Do not delay for imaging. Needle decompression is a time-critical, potentially life-saving intervention.

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Indications & Recognition

Clinical diagnosis — do not await imaging

⚡ Tension Pneumothorax Suspected?

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Classic Presenting Features

Triad of Suspicion

RespiratoryAbsent / markedly reduced breath sounds unilaterally
CirculatoryHaemodynamic compromise — hypotension, tachycardia, shock
MechanismPenetrating chest trauma, blunt chest trauma, rib fractures, iatrogenic (IPPV)

Additional Signs

Supporting Features

  • Tracheal deviation (late sign — away from affected side)
  • Distended neck veins / JVD (may be absent in hypovolaemia)
  • Increasing ventilator pressures (intubated patient)
  • Cyanosis / worsening SpO₂
  • Pulseless Electrical Activity (PEA) arrest with chest trauma
  • Hyper-resonance to percussion on affected side
  • Subcutaneous emphysema
⚠ Cardiac Arrest Context In traumatic PEA arrest, perform bilateral needle decompression without waiting for unilateral signs. Tension pneumothorax is a reversible cause of cardiac arrest (4Hs and 4Ts).

JRCALC Indications (2024)

Perform ND When:

  • Clinical signs of tension pneumothorax in spontaneously breathing patient
  • Clinical signs of tension pneumothorax in ventilated patient
  • Traumatic cardiac arrest / PEA with penetrating chest trauma
  • Traumatic cardiac arrest / PEA with mechanism consistent with tension PTX
  • Open chest wound with worsening respiratory distress despite wound seal
ℹ NWAS Guidance If first attempt fails to improve clinical picture, attempt second decompression at alternative site (contralateral side or alternative anatomical route). Consider bilateral decompression in traumatic arrest.
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Anterior Route

2nd Intercostal Space · Midclavicular Line

⚠ Landmark Critical Needle must pass over the superior border of the 3rd rib to avoid the neurovascular bundle (nerve, artery, vein) running beneath each rib.

📐 Anterior Chest — Right Side Shown

CLAVICLE STERNUM 1 2 3 4 5 6 MCL MIDCLAVICULAR 2nd ICS ← insertion SUPERIOR BORDER 3rd NVB BELOW RIB Insertion site Midclavicular line 2nd ICS
Space2nd Intercostal Space (between rib 2 and rib 3)
LineMidclavicular Line (MCL) — midpoint of clavicle, vertical
BorderSuperior border of 3rd rib — avoids neurovascular bundle
AnglePerpendicular to chest wall — 90°
DepthAdvance until hiss / loss of resistance — typically 3–5 cm adult

Step-by-Step Landmark Identification

How to Find the 2nd ICS MCL

  1. Identify the sternal notch (suprasternal notch) at the top of the sternum with your index finger.
  2. Move inferiorly — the first bony prominence is the sternal angle (Angle of Louis), a transverse ridge where the manubrium meets the body of the sternum.
  3. The 2nd rib articulates with the sternum at the Angle of Louis — use this as your reference point.
  4. Move one finger-width laterally and inferiorly — you are now in the 2nd intercostal space.
  5. Move your finger along the 2nd ICS laterally until you reach a point directly below the midpoint of the clavicle — this is the MCL.
  6. Your insertion point is at the 2nd ICS on the MCL, over the superior border of the 3rd rib.
⚠ Avoid Internal mammary artery runs ~1 cm lateral to sternal edge. Stay lateral at MCL. Never insert medially.

Advantages of Anterior Route

When to Prefer Anterior

  • Traditional JRCALC first-line approach
  • Easier access in supine patient
  • Suitable during CPR without interruption
  • Easier to visualise and confirm placement
  • Standard position for most training and practice

Limitations of Anterior Route

Potential Issues

  • Higher failure rate in obese/muscular patients — chest wall thickness
  • Cannula may kink or dislodge with patient movement
  • 16G standard cannula may be insufficient — use 14G minimum
  • Lung tissue may re-obstruct cannula if PTX decompressed
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Mid-Axillary Route

4th / 5th Intercostal Space · Anterior Axillary Line / Mid-Axillary Line

ℹ JRCALC 2024 Recommended Route The 4th/5th ICS anterior axillary line is now considered the preferred site by JRCALC (2024) for needle decompression in trauma patients, offering lower failure rates and greater safety margin.

📐 Lateral Chest Wall — Right Side

ARM AXILLA ANT. AXL MID AXL 1 2 3 4 5 6 4th/5th ICS NIPPLE (♂≈4th ICS) SAFE ZONE Insertion site Ant. axillary line Mid axillary line 4th/5th ICS
Space4th or 5th Intercostal Space
LineAnterior or Mid-Axillary Line (AAL preferred)
BorderSuperior border of 5th (or 6th) rib — avoids neurovascular bundle
ReferenceMale nipple ≈ 4th ICS level (anatomical guide only — unreliable)
AnglePerpendicular to chest wall — 90°
DepthAdvance until hiss / loss of resistance — typically 3–5 cm adult

Step-by-Step Landmark Identification

How to Find the 4th/5th ICS MAL

  1. Raise or abduct the patient's arm to expose the axilla — ideally to 90°. If trauma prevents this, use maximum accessible position.
  2. Identify the anterior axillary fold — the fold of skin/muscle at the front of the axilla formed by pectoralis major. The anterior axillary line (AAL) runs vertically from this fold.
  3. Identify the posterior axillary fold (latissimus dorsi). The midpoint between AAL and PAL is the mid-axillary line (MAL).
  4. Count ribs from the Angle of Louis (2nd rib) downward: 3rd, 4th, 5th. Alternatively: the male nipple lies at approximately the 4th ICS — use as a rough guide only.
  5. Your target is 4th or 5th ICS on the AAL or MAL. Palpate the rib below your target space and insert over its superior border.
  6. Avoid going below the 5th ICS — risk of intra-abdominal penetration, especially in trauma patients with raised diaphragm.
⚠ Critical Safety Do NOT insert below the 5th ICS / nipple line — risk of diaphragm, liver (right), or spleen (left) penetration. The safe zone is 4th–5th ICS between AAL and MAL.

Advantages of Mid-Axillary Route

When to Prefer MAL

  • Thinner chest wall — lower failure rate, especially in obese patients
  • JRCALC 2024 preferred primary site for trauma
  • Better suited to thoracostomy conversion (same incision site for finger thoracostomy)
  • Reduces risk of internal mammary artery injury
  • Less muscle bulk to penetrate vs anterior chest
  • Preferred in patients with chest wall deformity or burns to anterior chest

Limitations of MAL Route

Potential Issues

  • Arm position required — may not be possible in trauma
  • Access more difficult during active CPR
  • Risk of intra-abdominal injury if too low
  • Landmark identification can be harder in obese patients
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Equipment & Cannula Choice

Large bore IV cannula — minimum 14G recommended

⚠ Gauge Matters Standard 18G or 16G cannulae are often insufficient to penetrate the chest wall and maintain patency. Use the largest gauge available — 14G minimum. Some systems use purpose-made ND devices.

Cannula Selection

Recommended Equipment

Gauge14G minimum — 14G or 16G standard prehospital
LengthStandard IV cannula 45 mm — may be insufficient in obese patients. 70 mm preferred where available
TypeStandard large bore IV cannula (e.g. Venflon 14G) — needle withdrawn, cannula remains
AlternativePurpose-made ND devices (e.g. Pneumostat, ARS — Chest Seal with vent) where available

Why Cannula Length Matters

Chest Wall Thickness Data

Studies show mean chest wall thickness at 2nd ICS MCL ranges from 3.8–5.4 cm in adults, with obese patients exceeding 8 cm.

Standard 45mmAdequate in most adults — failure rate ~10–30% in obese
70mm cannulaSignificantly reduces failure rate — preferred if available
MAL 4th/5th ICSThinner chest wall — 45mm usually adequate

Full Equipment List

Required Equipment

  • Large bore cannula — 14G minimum (orange cap)
  • Gloves (non-sterile acceptable in emergency)
  • Skin prep wipe / chlorhexidine swab if immediately available
  • Tape or dressing to secure cannula after insertion
  • Scissors or trauma shears to expose chest
ℹ Aseptic Technique In a time-critical emergency, do not delay for full aseptic technique. Clean skin if a wipe is immediately to hand. Sterile technique is preferred but must not delay intervention.
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Step-by-Step Procedure

Tap each step to mark as completed — timestamps auto-logged

Select Side

Right
R side affected
Left
L side affected

Select Route

Anterior

2nd ICS Midclavicular Line

Mid-Axillary

4th/5th ICS AAL/MAL

Procedure Steps

Step 1
Expose chest wall. Visually confirm and re-examine: absent breath sounds, mechanism. Identify affected side. Call out to crew.
Step 2
Prepare largest available cannula — 14G minimum. Remove cap. Gloves on. Expose and prep skin with wipe if immediately available.
Step 3
Identify landmarks.
Anterior: 2nd ICS MCL — palpate Angle of Louis → 2nd rib → 2nd ICS → MCL. Insert over superior border of 3rd rib.
MAL: 4th/5th ICS AAL/MAL — count from Angle of Louis or use nipple line as guide. Insert over superior border of rib below.
Step 4
Insert needle perpendicular (90°) to chest wall. Advance slowly and steadily over the superior border of the rib. Apply gentle negative pressure with empty syringe if available.
Step 5
Advance until audible hiss of air or sudden loss of resistance. This confirms entry into pleural space. Do not advance further once confirmed.
Step 6
Withdraw the metal needle while holding the plastic cannula in position. Advance cannula slightly if needed. Leave cannula open to air — do not cap. Tape/secure in position.
Step 7 — Reassess
Immediately reassess: breath sounds both sides, SpO₂, HR, BP, skin colour, conscious level. Improvement should be rapid if tension PTX was present.
Step 8 — Communicate
Pre-alert receiving hospital. State: mechanism, side, route used, response to decompression. Consider bilateral if no improvement.
⚠ No Improvement After ND? If no clinical improvement after first decompression: re-check landmarks and cannula position → attempt second ND at alternative site (different anatomical route or contralateral side) → consider finger thoracostomy if trained and available.
⚠ Cannula Occlusion Cannula may become kinked, clotted, or obstructed by lung tissue. If patient deteriorates after initial improvement, reattempt decompression at same or alternative site. Check cannula patency.
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Complications & Troubleshooting

Recognition and management

Procedure Complications

Failure to Decompress

  • Most common cause: chest wall too thick — cannula not long enough to reach pleural space
  • Incorrect landmark identification
  • Insertion below superior rib border — cannula blocked by periosteum
  • Action: Reattempt with longer/wider cannula at MAL (thinner wall) or alternative site

Cannula Kinking / Occlusion

  • Plastic cannula kinks under skin pressure
  • Lung tissue re-expands and occludes tip
  • Blood or secretions occlude lumen
  • Action: Reassess clinically, reattempt decompression, consider finger thoracostomy

Iatrogenic Pneumothorax

  • If decompression performed on wrong side or wrong diagnosis
  • Clinical deterioration after procedure should raise suspicion
  • Action: Reassess both sides. If simple PTX created, monitor closely. Inform hospital.

Vascular Injury

  • Intercostal vessels — if inserted inferior to rib border
  • Internal mammary artery — if too medial on anterior route
  • Subclavian vessels — if too superior / medial
  • Prevention: Strict adherence to landmarks. Insert over superior rib border. Stay at MCL or lateral.

Organ Injury (MAL Route)

  • Diaphragm, liver (right) or spleen (left) if inserted below 5th ICS
  • More likely in trauma with raised diaphragm or hepatomegaly
  • Prevention: Do not insert below 5th ICS / nipple line. Count ribs carefully.

Subcutaneous Emphysema

  • Air tracking subcutaneously — common, not usually harmful
  • May impair subsequent landmark identification
  • Document and inform hospital

If No Improvement After Needle Decompression

Decision Pathway

  1. Was tension PTX the correct diagnosis? Reassess clinical signs.
  2. Check cannula — is it still in position? Patent? Not kinked?
  3. Reattempt at same site with new/longer cannula.
  4. Attempt alternative anatomical route (anterior ↔ MAL).
  5. Consider contralateral decompression — bilateral tension PTX.
  6. If trained: finger thoracostomy — definitive emergency thoracic decompression.
  7. Reassess for other reversible causes (haemothorax, cardiac tamponade).
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Documentation / PCR Output

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Intervention Log

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PCR Text Output

Documentation Checklist

✓
Time of decompression recorded
✓
Side (left/right) documented
✓
Anatomical route documented (anterior 2nd ICS MCL / MAL 4th/5th ICS)
✓
Cannula gauge and length documented
✓
Indication (clinical signs) documented — breath sounds, mechanism, haemodynamics
✓
Presence / absence of audible hiss on insertion documented
✓
Post-procedure clinical response documented (improved / unchanged / deteriorated)
✓
Number of attempts documented
✓
Pre-alert to receiving hospital documented
✓
Cannula left in situ confirmed / documented
✓
Handover to hospital team given and acknowledged