Cricothyrotomy
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# Overview
A cricothyrotomy (also called thyrocricotomy, cricothyroidotomy, inferior laryngotomy, intercricothyrotomy, coniotomy or emergency airway puncture) is an emergency incision through the skin and cricothyroid membrane to secure a patient's airway during certain emergency situations, such as an airway obstructed by a foreign object or swelling, a patient who is not able to breathe adequately on their own, or in cases of major facial trauma which prevent an airway through the mouth. A cricothyrotomy is usually performed by emergency physicians, trauma surgeons, or paramedics as a last resort when control of the airway by usual means (an endotracheal tube through the mouth) have failed or are not feasible. This technique is considered easier and faster than a tracheostomy, but is only used when oral or nasual intubation is not possible in the patient.  This procedure does not require manipulation of the cervical spine.  However, it does require special training and authorization from local medical direction prior to being performed, dependending on local medical protocols.

# Indications
- Severe facial or nasal injuries (that do not allow oral or nasal intubation)
- Massive midfacial trauma
- Possible spinal trauma preventing adequate ventilation
- Anaphylaxis
- Chemical inhalating injuries

# Contraindications
- Inability to identify landmarks (cricothyroid membrane)
- Underlying anatomical abnormality (tumor)
- Tracheal transection
- Acute laryngeal disease by infection or trauma
- Small children under 10 years old (a 12-14 gauge catheter over the needle may be safer)

# Complete
OVERVIEW
- open procedure performed to secure the airway via an incision in the cricothyroid membrane
- aka emergency surgical airway (ESA)
- distinct from needle cricothyroidomtomy (aka emergency cannula cricothyroidotomy), which is an alternative approach to front of neck access (FONA)
INDICATIONS
- cant intubate, cant ventilate (CICV) scenario
CONTRA-INDICATIONS
- ability to secure an airway with less invasive means
- airway trauma that renders access via the cricothyroid membrane futile
e.g. laryngeal fracture, tracheal transection
tracheostomy should be performed, or access achieved via the traumatic airway opening
- e.g. laryngeal fracture, tracheal transection
- tracheostomy should be performed, or access achieved via the traumatic airway opening
- Children < 10 years of age
young children are prone to laryngeal trauma and they have a higher incidence of postoperative complications)
perform needle cricothyrotomy is generally advised, however life-saving surgical cricothyroidotomy has been successfully performed in children
- young children are prone to laryngeal trauma and they have a higher incidence of postoperative complications)
- perform needle cricothyrotomy is generally advised, however life-saving surgical cricothyroidotomy has been successfully performed in children
DESCRIPTION
- Numerous techniques have been described, my preferred approach is the knife-finger-bougie approach (Described below)
- in an anticipated difficult airway requiring emergency intubation a double set up approach should be used if possible
-ne person attempts intubation
another person prepares to perform the ESA
dons mask, visor, gown and gloves
marks the skin marked with surgical pen to identify cricothyroid membrane
locates cricothyroid membrane area and infiltrate skin and fascia with lignocaine with adrenaline (can be done while patient is awake if cooperative)
Has equipment opened and ready to procedure with the procedure when advised by the team leader
- one person attempts intubation
- another person prepares to perform the ESA
dons mask, visor, gown and gloves
marks the skin marked with surgical pen to identify cricothyroid membrane
locates cricothyroid membrane area and infiltrate skin and fascia with lignocaine with adrenaline (can be done while patient is awake if cooperative)
Has equipment opened and ready to procedure with the procedure when advised by the team leader
- dons mask, visor, gown and gloves
- marks the skin marked with surgical pen to identify cricothyroid membrane
- locates cricothyroid membrane area and infiltrate skin and fascia with lignocaine with adrenaline (can be done while patient is awake if cooperative)
- Has equipment opened and ready to procedure with the procedure when advised by the team leader
- in a true emergency there may not be time for sterile preparation of the skin
- consider sedation (e.g. IV ketamine 20 mg prn)  there may not be time in a true emergency and the patient will become obtunded as hypoxia supervenes
- ESA is a tactile procedure and must be able to be performed without visual cues
Knife-finger-bougie approach
- Equipment
scalpel blade (e.g. size 10)
artery forceps
bougie
size 6-0 ETT (or tracheostomy tube)
- scalpel blade (e.g. size 10)
- artery forceps
- bougie
- size 6-0 ETT (or tracheostomy tube)
- once decision made to proceed with ESA extend neck in supine position to make anatomy more accessible by palpation (aka the laryngeal handshake) +/- ultrasound (if time and available); note that airway has priority over suspected c-spine injury
- stabilise the thyroid cartilage with the non-dominant hand
- dominant hand holds scalpel and rests on the patients sternum for stability and support
- 4 cm vertical incision through skin over cricothyroid membrane, may need to extend from mandible to sternum if impalpable anatomy (step may not be necessary if easily palpable anatomy  can go straight to the horizontal incision)
- Once skin incised, palpate cricothyroid membrane position and blunt dissect with fingers (some prefer forceps) through subcutaneous tissue until the membrane is readily identifiable. Ignore bleeding until airway is secure (ETT placement usually has a tamponade effect)
- Horizontal incision through membrane, drag scalpel blade from one side to the other then turn knife through 180 degrees and extend to the other side (some prefer to extend the membrane with forceps). The criciothyroid membrane is bound by a cartilagenous cage so resistance will be felt at the margins of the membrane when the scalpel blade abuts cartilage.
- Dilate with gloved little finger and palpate tracheal lumen, ideally identifying the cartilage of the posterior wall of the trachea/ cricoid ring
- Pass bougie alongside little finger into trachea
- Confirm bougie position with finger, ensuring it passes through membrane
- Bougie usually holds up at carina <10cm from the skin (may feel tracheal rings as the bougie advances), do not force if hold up as may perforate carina
- Pass ETT over bougie and intubate trachea. Ensure the ETT balloon is fully deflated and twist ETT as it passes the skin (hold up here is common). Only advance the ETT until the balloon is within the airway and no longer visible (if advanced further then endocbronchial intubation is likely).
- Ensure ETT is held secure while bougie is removed and ETT is connected to BVM
- Confirm ETT placement with ETCO2 (also adjunctive measures: auscultation, bilateral rise and fall of chest, fogging of tube and subsequent CXR)
Scott Weingart teaching the knife-finger-bougie approach at smaccGOLD 2015 (this is also the preferred approach taught on the Critically Ill Airway course):
Darren Braudes video of the knife-finger-bougie bougie-assisted cricothyroidotomy (note that the vertical incision is not shown as the anatomy is readily identifiable):
Andy Heards three step bougie-assisted cricothyroidotomy  technique
- This is similar to the knife-finger-bougie technique described above, except the bougie is inserted alongside the vertically oritentated scalpel while it is in the airway, rather than the little finger
- Make a midline longitudinal incision with No. 20 blade over cricothyroid membrane and use nondominant index finger to palpate membrane
- Make a 5-mm transverse incision through membrane and insert a gum elastic bougie into trachea alongside the vertically orientated scalpel
- Place cuffed 6.0-mm ET tube over bougie and slide into trachea; once in place remove bougie and secure ET tube
Andy Heards bougie-assisted cricothyroidotomy video:
Standard approach to surgical cricothyroidotomy using tracheal hook and Trousseau dilator
- Make a longitudinal midline incision over the cricoid membrane
- Identify the cricothyroid membrane via blunt dissection
- Make a short transverse stab incision in the lower part of the membrane
- Stabilize the larynx with a tracheal hook at the inferior aspect of the thyroid cartilage
- Dilate the ostomy with curved hemostats
- Place Trousseau dilator in the incision and further dilate the ostomy
- Place tube in the trachea
Scott Weingarts open cricothyroidotomy video:
Three step knife-and-tube approach to surgical cricothyroidotomy (uses handle of scalpel to maintain access to airway when passing the endotracheal tube):
- non-dominant hand secures trachea
- Make a longitudinal midline incision over thyroid and cricoid cartilages followed by a transverse stab incision through cricothyroid membrane
- Insert handle into cricothyroid membrane opening and rotate 90
- Insert 6.0-mm tube, inflate cuff and secure
Video by Siamek Moayedi (note this video also shows use of a tracheal hook to stabilise the trachea):
COMPLICATIONS
- failure
- bleeding
- infection
- damage to local structures  e.g. larynx, vessels, nerves, esophagus, cartilage, muscle
- cricoid fracture
- fistula formation
- scarring
- hypoxia
- death
OTHER INFORMATION
Incision
- An initial horizontal incision can be used if palpable anatomical landmarks allow easy identification of the cricothyroid membrane
- In patients where the anatomy cannot be easily palpated (e.g. obesity, short neck, neck swelling), a long midline longitudinal incision should be made to facilitate accurate identification of the cricothyroid membrane
- Landmark identification of the cricothyroid membrane is often unreliable, in a small study only 30% attempts by anaesthetists accurately marked the skin area over the cricothyroid membrane and only 10% marked over the centre point of the membrane (Elliot et al, 2010)
Surgical cricothyroidotomy versus cannula cricothyroidotomy
- The NAP4 audit in the UK found a ~60% failure rate for emergency cannula cricothroidotomy, whereas surgical cricothyroidotomy was almost universally successful
- It is not clear if the cannula approach is intrinsically inferior, or whether other factors may have contributed to the low success rate
- Nevertheless, this data supports the use of surgical cricothyroidotomy
Speed of surgical cricothyroidomty
- Most traditional surgical cricothyrotomy procedures are faster than percutaneous techniques, with the average speed 83  44s (range, 28149s) (Paix and Griggs, 2011)
- Hill et al (2010) found that a bougie-assisted technique is even faster than standard open cricothyroidotomy techniques in  a sheep model (median time of 67s (interquartile range  = 55-82) versus 149s (IQR = 111-201) for the standard technique (p = 0.002)
- The CricKey is a novel surgical cricothyroidotomy device combining the functions of a tracheal hook, stylet, dilator, and bougie incorporated with a Melker airway cannula. Mabry et al (2014) found that first-attempt success was 100% (15/15) for CricKey surgical cricothyroidotomy and 66% (10/15) for open surgical cricothyroidotomy (odds ratio 16.0; 95% CI 0.8 to 326). Surgical cricothyroidotomy insertion was faster for CricKey than open technique (34 versus 65s; median time difference 28s; 95% CI 16 to 48s).

# Summarized Technique
- With a scalpel, create a 2 cm horizontal incision through the cricothyroid membrane
- Open the hole by rotating the scapel 90 degrees or by using a clamp
- Insert a size 6 or 7 Endotracheal tube or tracheostomy tube
- Inflate the cuff and secure the tube
- Provide venilation via a Bag-Valve device with the highest available concentration of oxygen
- Determine if ventilation was successful (bilateral ausculation and observing chest rise and fall)
No attempt should be made to remove the Endotracheal tube in a prehospital setting.