Anatomy of the ET Tube

⏺ 15 mm connector – standardized on all airway equipment to avoid a situation where somebody had to look for the right adaptor

⏺ Pilot balloon – contains a spring-loaded one way valve to inflate the balloon.

⏺ One way valve – prevents the air from leaking out when the syringe is disconnected

⏺ Inflatable cuff – has 2 purposes: seals the trachea so that 1) positive pressure can’t escape from lower airways, and 2) seals the trachea so patient doesn’t aspirate any secretions or stomach contents coming from upper airway

⏺ Magill Curve – a natural curvature of approximately 140mm radius, +/- 20mm

⏺ Black line – suggested vocal cords marker

⏺ Size of the ETT – is the internal diameter of the tube

⏺ Depth markings – allow us to measure the depth of the ETT at the teeth or lips (typically 3x size of ETT)

⏺ Radio-opaque line (white here, but I’ve also seen blue!) – helps with the identification of the ETT on X-ray

⏺ Murphy’s Eye – an opening on the right side that allows for ventilation, if the primary opening gets occluded.

Difficult Airway

  • MOANS – difficult BVM
  • LEMON – difficult laryngoscopy
  • The Two Minute Drill: How I Prep My Airways
  • The Bloody Airway: The Trauma Airway and the GI bleeder
  • The Obstructed Airway: Angioedema and Deep Space Infections

Paediatric “tube” sizes

You decided to intubate a child and wisely remembered that you should also follow with an NG/ OG after intubation to decompress the stomach.  In order to avoid the blank stare when asked “what size”?  Here’s a nice mnemonic about Pediatric “tube” sizes… easy as 1-2-3-4!!!  Please note ETT = endotracheal tube size.

  • 1 x ETT = (age/4) + 4 (formula for uncuffed tubes)
  • 2 x ETT = NG/ OG/ foley size
  • 3 x ETT = depth of ETT insertion
  • 4 x ETT = chest tube size (max, e.g. hemothorax)

So for example, a 4-year-old child would get intubated with a 5-0 ETT inserted to depth of 15 cm (3x ETT), a 10Fr NG/OG/foley (2x ETT), and a 20Fr chest tube (4x ETT).

Also, remember that you can use cuffed tubes in any child except neonates but the formula needs to be adjusted as follows: cuffed endotracheal tube ID (mm) = (age/4) + 3.5

Rapid Sequence Intubation Medications

Induction Agents

Medication Weight-Based Dosing Time to Onset of Action Adverse Effects/

Contraindications

Etomidate 0.3 mg/kg <1 minute May cause clinically insignificant adrenal suppression.
Ketamine 1-2 mg/kg 1-3 minutes May increase blood pressure. May cause hypersalivation.
Propofol 2 mg/kg <1 minute May cause hypotension. Cardiac depressant. Contraindicated in egg/soybean allergy
Midazolam 0.3 mg/kg 1-5 minutes May cause hypotension

Paralytics

Medication Weight-Based Dosing Time to Onset of Action Adverse Effects/

Contraindications

Succinylcholine 1.5 – 2.0 mg/kg 45-60 seconds Bradycardia. Malignant hyperthermia. Hyperkalemia.
Rocuronium 1.2 mg/kg 45-60 seconds
Vecuronium 0.1 mg/kg 2-4 minutes Questionable RSI utility when rocuronium available

Post-Intubation Sedation

Medication Weight-Based Dosing Notes
Midazolam 0.04-0.2 mg/kg/hr Short duration, but with long-term use has long half-life. Often used with fentanyl
Propofol 5-80 mcg/kg/min Propofol Infusion Syndrome with long term use: monitor TG, amylase/lipase
Dexmedetomidine 0.2-0.7 mcg/kg/hr
Ketamine 0.5-1 mg/kg/hr May decrease bronchospasm
Fentanyl 1-2 mcg/kg bolus25-250 mcg/hr

 

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