Cricothyroidotomy kits: needle vs surgical

Where this fits in CICO algorithms

Used for emergency front-of-neck access (eFONA) in a “can’t intubate, can’t oxygenate” situation after failed oxygenation via supraglottic airway and optimized attempts.
- DAS guidance in adults generally favours surgical cricothyroidotomy (scalpel–bougie–tube) as first-line eFONA; needle techniques are alternatives/bridges depending on kit availability and operator skill.
Goal: restore oxygenation quickly; definitive airway can follow once oxygenation achieved (often conversion to cuffed tracheal tube).

Decision: needle vs surgical (adult)

Surgical cricothyroidotomy provides a cuffed airway allowing conventional ventilation and better protection from aspiration.
Needle cricothyroidotomy provides oxygenation via transtracheal cannula; ventilation is limited (especially CO2 clearance) and failure rates can be higher if not using a purpose-designed wide-bore cannula with a dedicated ventilation device.
- If using a narrow-bore cannula, you must use a high-pressure source with a purpose-designed jet ventilator and ensure an expiratory route is patent.
Pragmatic: use the technique you can perform fastest and most reliably with the kit immediately available; be ready to convert needle → surgical if oxygenation/ventilation inadequate.

Landmarks and preparation (both techniques)

Identify cricothyroid membrane (CTM): between thyroid cartilage and cricoid cartilage; consider “laryngeal handshake”.
Position: ideally neck extended (unless trauma); call for help; 100% oxygen; stop repeated laryngoscopy; ensure full neuromuscular blockade if appropriate (reduces laryngospasm/chest wall rigidity and improves access).
Scalpel ready; suction; capnography available; confirm placement with ETCO2 where possible.

Needle cricothyroidotomy: equipment and principles

Cannula: purpose-designed cricothyroidotomy cannula (preferably wide-bore, kink-resistant) with secure fixation and compatible connector/jet adaptor.
- Narrow-bore IV cannulae are prone to kinking, displacement, and inadequate flow; if used, treat as a temporising measure and plan rapid conversion.
Oxygen delivery options: (1) high-pressure jet ventilation device; (2) some kits allow connection to standard breathing circuit via 15 mm connector (usually requires larger internal diameter).
Physiology: oxygenation can be achieved with insufflation/jetting, but CO2 elimination may be poor; hypercapnia and acidosis can develop quickly.
Critical safety requirement: an expiratory path must be available (upper airway patent or a second lumen/route). If not, risk of barotrauma and circulatory collapse.
- Complete upper airway obstruction + jet ventilation through a cannula can cause air trapping, pneumothorax, pneumomediastinum, and subcutaneous emphysema.

Needle cricothyroidotomy: technique (generic steps)

Stabilise larynx; puncture CTM in midline aiming caudally (reduces risk of posterior wall injury); aspirate air to confirm tracheal entry.
Advance cannula, withdraw needle; secure cannula; confirm with capnography if ventilating; start oxygenation with appropriate device.
Ventilation strategy (jet): short inspiratory pulses with adequate time for passive expiration; monitor chest rise, oxygenation, and signs of air trapping.
If oxygenation not rapidly restored or ventilation unsafe/inadequate: proceed to surgical cricothyroidotomy without delay.

Surgical cricothyroidotomy: equipment and principles

Core kit: scalpel (often #10/#11), bougie (or tracheal introducer), cuffed tube (commonly 6.0 mm ID) or dedicated cric tube, syringe, ties/tape.
Advantages: definitive cuffed airway, allows standard ventilation (including PEEP), capnography confirmation, suctioning, and better airway protection.
Disadvantages: bleeding, false passage, posterior tracheal wall injury; requires incision and familiarity with technique.

Surgical cricothyroidotomy: technique (scalpel–bougie–tube)

Make a horizontal stab incision through skin and CTM (or vertical skin incision then horizontal membrane incision if landmarks difficult).
- Rotate scalpel 90° to open the membrane and maintain access.
Insert bougie through incision into trachea (feel tracheal rings/hold-up); railroad a cuffed tube over bougie; inflate cuff.
Confirm with capnography and chest rise; secure tube; ventilate with standard circuit; manage bleeding and consider conversion to formal tracheostomy later if indicated.

Comparison: needle vs surgical (adult) — key exam contrasts

Speed and reliability: surgical often more reliable in experienced hands; needle may be quick but prone to kinking/dislodgement and inadequate ventilation.
Ventilation: surgical allows conventional ventilation and CO2 clearance; needle primarily oxygenation with variable CO2 clearance (worst with narrow-bore cannula).
Aspiration protection: surgical provides cuff; needle does not.
Complications: needle—barotrauma/air trapping, misplacement, subcutaneous emphysema; surgical—bleeding, false passage, laryngeal/tracheal injury.
Human factors: under stress, a simple reproducible method with a standardised kit reduces cognitive load; pre-briefing and regular training are critical.

Kit examples (what you might see in theatre/ICU)

Needle/cannula kits: wide-bore cric cannula with Seldinger option; jet ventilation adaptor; securing flange.
Surgical kits: scalpel + bougie + 6.0 cuffed tube packaged as an eFONA set; some include tracheal hook/dilator.
Know your local kit: location, contents, connector compatibility, and which oxygen source/device is required.

Confirmation and post-procedure management

Confirm placement: continuous waveform capnography is the best confirmation when ventilation is possible; also observe chest rise, auscultation, improving SpO2.
After needle: treat as temporary; plan conversion to cuffed airway (surgical cric or tracheostomy) once oxygenation secured.
After surgical: secure well; consider gastric decompression; manage bleeding; analgesia/sedation; ICU transfer; document and debrief.

You are called to a CICO event in theatre. Talk me through your immediate plan and where needle vs surgical cricothyroidotomy fits.

Structure your answer around restoring oxygenation, stopping ineffective attempts, and moving decisively to eFONA.

Declare CICO; call for help; allocate roles; 100% oxygen; stop further laryngoscopy; attempt best oxygenation with facemask/SAD only if it does not delay eFONA.
Proceed to eFONA: in adults, default to surgical cricothyroidotomy (scalpel–bougie–tube) if trained and kit available; needle is an alternative/bridge depending on local kit and skill.
Once oxygenation restored: confirm with capnography, secure airway, stabilise patient, and plan definitive airway/ICU.

Compare needle cricothyroidotomy with surgical cricothyroidotomy: indications, advantages, disadvantages, and complications.

A common FRCA viva: contrast oxygenation vs ventilation, reliability, and complication profiles.

Needle: rapid access and minimal incision; primarily oxygenation; ventilation/CO2 clearance limited; no cuff/aspiration protection; risks include kinking/dislodgement, misplacement, barotrauma, subcutaneous emphysema.
Surgical: cuffed tube enables conventional ventilation, capnography, suctioning, and aspiration protection; more invasive; risks include bleeding, false passage, posterior wall injury, tube misplacement.
Indication for both: CICO/eFONA; choice depends on adult vs paediatric context, operator training, and kit/device availability.

Describe how you would perform a needle cricothyroidotomy and then oxygenate/ventilate through it. What are the key safety points?

Examiners want a stepwise technique plus the physiology and safety constraints of jet ventilation.

Identify CTM; stabilise larynx; puncture midline aiming caudally; aspirate air; advance cannula and remove needle; secure cannula.
Connect to appropriate device: preferably purpose-designed jet ventilator/adaptor for narrow-bore; deliver short inspiratory jets with long expiratory time; monitor chest rise and SpO2.
Key safety: ensure an expiratory route; if upper airway obstructed, jetting risks air trapping and barotrauma; watch for subcutaneous emphysema and rising airway pressures/poor chest deflation.
If oxygenation not promptly restored or ventilation inadequate: convert to surgical cricothyroidotomy.

Describe the scalpel–bougie–tube technique for surgical cricothyroidotomy, including how you confirm correct placement.

Give a reproducible sequence and include confirmation with waveform capnography.

Palpate CTM; make horizontal stab incision through CTM (or vertical skin incision first if difficult); rotate scalpel to open the tract.
Insert bougie into trachea; railroad a 6.0 cuffed tube; inflate cuff; ventilate with circuit.
Confirm: continuous waveform capnography, chest rise, auscultation, improving oxygenation; then secure tube.

A patient has complete upper airway obstruction. What are the risks of jet ventilation via a needle cricothyroidotomy and how do you mitigate them?

This is a high-yield physiology/safety viva.

With no expiratory path, insufflated/jet gas cannot escape → progressive air trapping → high intrathoracic pressure → pneumothorax/pneumomediastinum, subcutaneous emphysema, reduced venous return, cardiovascular collapse.
Mitigation: prefer surgical cricothyroidotomy (cuffed tube) in complete obstruction; if needle used as bridge, use minimal insufflation, allow long expiratory times, and convert urgently to surgical airway.

Your needle cricothyroidotomy cannula is in place but oxygenation is not improving. What are your differentials and actions?

Think: displacement, obstruction, wrong device, no expiratory route, and progression to definitive eFONA.

Check patency and position: kinking, blockage with blood/secretions, posterior wall placement, subcutaneous placement; reassess by aspiration of air and clinical signs.
Check equipment: correct connector/adaptor, oxygen source pressure, functioning jet device, secure connections.
Consider physiology: complete obstruction preventing expiration; severe bronchospasm; tension pneumothorax from barotrauma.
Immediate action: proceed to surgical cricothyroidotomy; treat suspected tension pneumothorax if present; continue best possible oxygenation attempts while converting.

What size tube would you choose for an adult surgical cricothyroidotomy and why?

They are testing practicality and understanding of resistance/railroading.

Common choice: cuffed 6.0 mm internal diameter tube (or dedicated cric tube) — balances ease of insertion through CTM with ability to ventilate and pass suction catheter.
Larger tubes may be harder to insert and increase trauma; smaller tubes increase resistance and limit suctioning/bronchoscopy.

How would you confirm correct placement of a surgical cricothyroidotomy tube vs a needle cannula?

Capnography is central; cannula confirmation can be harder if ventilation is limited.

Surgical tube: waveform capnography is the best confirmation; also chest rise, auscultation, misting, improving SpO2.
Needle cannula: aspiration of air on insertion; if ventilating/jetting, ETCO2 may be unreliable but any consistent CO2 trace supports tracheal placement; monitor for subcutaneous emphysema suggesting misplacement.

List the complications of (a) needle cricothyroidotomy and (b) surgical cricothyroidotomy.

Needle: misplacement (pretracheal/subcutaneous), kinking/obstruction, dislodgement, bleeding, posterior wall injury, barotrauma (pneumothorax/pneumomediastinum), subcutaneous emphysema, inadequate ventilation → hypercapnia/acidosis.
Surgical: bleeding/haematoma, false passage, oesophageal/posterior tracheal wall injury, subglottic stenosis (later), infection, tube displacement, damage to laryngeal cartilages/voice change.

In what situations might a needle technique be preferred over surgical cricothyroidotomy?

Answer should be cautious in adults and acknowledge guideline preferences while giving realistic scenarios.

When a purpose-designed cannula kit is immediately available and the operator is trained/experienced with it, and it can be delivered faster than surgical access.
As a temporising bridge when surgical kit/skill is not immediately available, with an explicit plan to convert to a cuffed airway.
Paediatric context differs: needle techniques may be used more commonly in small children due to anatomical constraints, but this depends on local guidance and expertise.

You have performed eFONA successfully. What are your next steps (clinical and governance)?

Clinical: secure tube/cannula; confirm ventilation/oxygenation; treat complications (bleeding, pneumothorax); sedation/analgesia; ICU transfer; plan definitive airway (often formal tracheostomy or tube exchange when stable).
Governance: document clearly (time, technique, kit, confirmation); inform patient/family when appropriate; debrief team; incident reporting and restocking/checking eFONA kit; arrange follow-up for airway injury/ENT review.