Cricothyrotomy Procedure Review

We had a cricothyrotomy in the ED this week. It's a good idea to review this procedure.

There are several techniques to the procedure, below are the steps to 2 techniques: standard and at 4 step technique -the latter I find easier to remember.
There are two videos which are useful - the first is about 2 minutes by Dr. Strayer - a real live cricothyrotomy and a second video by emrap with is longer (12 mins) and more detailed. I recommend watching at least the first, since it's on a real live patient, and shows a real life procedure.
Must watch:
https://vimeo.com/125228375
Watch this if you have 12 mins -more detailed and step wise instructions:
https://www.emrap.org/episode/emrapliveaugust/procedurereview2
Also* - wear a mask and shield.
 

Standard Technique:

  • Identify the Landmarks
    • Starting at the Sternal Notch, palpate superiorly until the Laryngeal Prominence is felt. The Cricothyroid Membrane will be approximately one fingerbreadth below this.
    • If not palpable with the prior method, place four fingers longitudinally across the neck with the 5th finger on the Sternal Notch. The Cricothyroid Membrane will be below your Index finger.
  • Prepare the Neck
    • Clean the neck with antiseptic. If time allows, infiltrate the skin and soft tissue with Lidocaine.
  • Stabilize the Larynx
    • Note: This is ESSENTIAL to success.
    • With the thumb and middle finger of the non-dominant hand, grip the posterolateral aspects of the Larynx, while leaving your index finger free to re-palpate the Cricothyroid membrane at any time.
  • Incise the Skin
    • With your dominant hand, make a 3.5 cm midline VERTICAL incision over the membrane.
  • Re-identify the Membrane
    • Use the non-dominant index finger to again relocate the membrane.
  • Incise the Membrane
    • Make a 1 cm HORIZONTAL incision on the lower edge of the membrane.
    • Note: The Cricothyroid vessels lie on the superior edge of the membrane. Making a lower incision helps avoid these vessels.
    • Aim the scalpel caudally to avoid injuring the vocal cords.
  • Once you have made the incision, slide the index finger of your non-dominant hand into the incision so as to not lose the opening.
  • Insert the Tracheal Hook
    • With your dominant hand, insert the hook TRANSVERSLY. Then, rotate it 90 degrees, so that the hook is oriented cephalad and lift the Larynx upward and cephalad. The hook may now be switched to your non-dominant hand or held by an assistant (preferable).
  • Insert the Trousseau Dilator
    • With your dominant hand, insert the dilator into the incision and GENTLY enlarge the incision in a vertical direction.
  • Remove the dilator place the tracheostomy (or endotracheal) tube over your finger and into the opening.
    • Note: A gum elastic bougie may be used in place of the above tubes.
  • Inflate the cuff and confirm placement.

Four-Step Technique:

  1. Identify the landmarks (as in the Standard Technique)
  2. Make a 1-2 cm HORIZONTAL stab incision through both the skin and cricothyroid membrane.
  3. BEFORE removing the scalpel, insert a tracheal hook and direct it caudally.
  4. Insert the tracheostomy tube through the incision into the trachea.
Sources: emrap, emupdates, Dr. Strayer's vimeo, wikem
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Comparison of 2 Apneic Oxygen Studies

Effectiveness of Apneic Oxygenation during Intubation:  A systemic review and meta-analysis by Silva et al 2017

  • Population:  ED and ICU patients; both RCT and observational studies included.
    • Not OR or outside hospital patients
  • Intervention:
    • Some received High Flow at 60L/min -Transnasal Humidified rapid insufflation ventilator exchange (THRIVE technique).  Some PEEP.
    • Some received Nasal cannula at 15L/Min (Nasal Oxygen during efforts securing a tube- NO DESAT).  No PEEP.
  • Comparison; no apneic ox although 3 studies did not have comparison groups
  • Outcome
    • Lowest SpO2 peri-intubation; usually measured from time of drug injection until mechanical ventilation but not available for all studies
      • In 6 studies, the lowest SpO2 was higher for the ApOx group than for standard ox (difference of 2.21%; 95% CI 0.81-3.61)
        • Crosses 1 but scale set so zero is the dividing line rather than the typical 1
    • First Pass success
      • In 6 studies, ApOx had increased first pass success OR 1.59; 95% CI 1.04-2.44)
    • Incidence of hypoxemia less than 93%
      • OR 0.66; 95%CI 0.52-0.84
    • Severe hypoxemia <80% - not significant
    • Life threatening hypoxemia <70%  - not significant
    • ICU length of stay – only 368 pts but statistically significant with mean decrease in length  of stay of 2.88 days in ap ox group
    • Mortality- not significant
  1. 14 studies for qualitative review
  2. 8 studies for quantitative review (out of the 14)
    1. 1837 patients.  932 pts had apneic oxygenation, 855 did not
    2. Apneic Ox had increased peri-intubation ox saturation difference of 2.21%; 95% CI 0.81-3.61
    3. Decreased rates of hypoxemia OR 0.66; 95%CI 0.52-0.84
      1. Not significant beneficial for cases of severe hypoxemia OR 0.86; 95% CI 0.47-1.57
    4. Increased first pass success OR 1.59; 95% CI 1.04-2.44
  3. Rationale:  apneic oxygenation revolves around physiologic capacity of continuous oxygen capture by alveoli through passive process without providing ventilation
  4. Used several tools to limit bias
  5. Only had a moderate kappa between 2 coders over which studies to include
  6. Limitations:
    1. moderate to low level of certainty in estimates
    2. different methods of Ap Ox (HF vs NC)
    3. Does higher rates of first pass success also mean less oxygen desaturation, affecting that result?
    4. When only using low risk of bias studies, none of the outcomes showed improvement with ApOx but the sample sizes were small/not enough power.

Emergency Department use of Apneic Oxygenation vs usual care during rapid sequence intubation:  a randomized controlled trial (The ENDAO Trial) by Caputo et al 2016

  • Population:  206 ED adult patients requiring intubation but excluding cardiac/traumatic arrest or people who didn’t get pre-oxygenation via NRB/bipap/bvm or awake intubation
  • Intervention:  Apneic oxygenation received nasal cannula oxygen and ETCO2 NC both at flush flow rates of >15L/min
  • Comparison:  Usual Care (just pre-oxygenation)
  • Primary Outcome:  Avg lowest O2 saturation during apnea period or in 2 minutes following intubation
    • Looked for a difference of 5% (Cohen’s D statistic of 0.4 for moderate effect size)
  • No difference between the 2 groups 92% Oxygen saturation; 95% CI 91-93 in AO vs 93, 95% CI 92-94in UC, p=0.11)
    • Secondary:
      • Increased first pass success?  Everyone except 22 patients.  Even these didn’t desat below 90 however 15 of them weren’t intubated for pulmonary reasons.
      • Decreased rates of desaturation below 90?  80?  No significant difference
      • Time to desaturation?  No significant difference
      • Mortality? No significant difference
  1. Pre-oxygenation is providing supplemental O2 w/ goal of 100% FiO2 for at least 3 minutes prior to RSI to increase amount of O2 in the functional residual capacity of the lungs
  2. Apneic oxygenation- leave the NC on after RSI and while visualizing the vocal corts/placing the ETTube.
  3. FELLOW trial showed no difference in desaturation rates between ApOx and usual practice in ICU patients; other studies refute these results
  4. Pre-oxygenation technique at discretion of attending (BVM vs Bipap vs NRB)
  5. Video vs DL and RSI meds at attending discretion
  6. Apnea time from first look (not Med push) to EtCO2 confirmation (not being placed on the vent)- this is a shorter time than the meta-analysis.
    1. Used this because you KNOW the patient is paralyzed/apneic
  7. Subgroup w/ prolonged apnea time of 130+seconds did not desaturate to less than 90%
  8. Limitations:  real time data collection may underestimate AE and time to intubation.  Also single center study in academic center.
  9. Similar results as FELLOW study but different in that everyone received pre-oxygenation.
  10. Perhaps Ap Ox would be useful in those who have not been pre-oxygenated?  E.g. crash intubations

 

 

 

Looking at both of these and how the conflict, consider the following:  Does it apply to your population?  Do you have the resources?  Any harms?  Any benefits that  you've seen?

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