Rapid Sequence Intubation (RSI)

Rapid Sequence Intubation (RSI)

David Ray Velez, MD

Table of Contents

General Technique
Pretreatment
Induction Agents
Paralytic Agents
Laryngoscopy
Rescue Techniques

General Technique

Rapid Sequence Intubation (RSI): A Technique to Induce Immediate Unresponsiveness and Muscular Relaxation to Facilitate Rapid Endotracheal Intubation

  • The Fastest and Most Effective Technique to Gain Control of an Emergency Airway
  • Mediation Administration is Rapid and Virtually Simultaneous with No Titration
  • The Most Common Approach for Emergency Intubation Outside of the Operating Room

Delayed Sequence Intubation (DSI): A Technique for Preoxygenation Prior to Endotracheal Intubation in Which an Induction Agent is Given to Sedate and Allow at Least 3-5 Minutes of Preoxygenation Prior to Paralysis and Intubation

  • Used for Patients that are Agitated or Otherwise Intolerant of Preoxygenation
  • Ketamine is the Most Commonly Described Induction Agent Given for Sedation (1 mg/kg)
  • Requires Extremely Careful Monitoring of Respiratory Status

Apneic Oxygenation: Provide Additional Oxygenation via Nasal Cannula and/or Face Mask After Induction Until Intubation is Achieved

  • Increases Minimum Oxygen Saturation but No Change in Risk of Severe Hypoxia, Shock, or Arrest

The “9 P’s” Process for RSI

  • Plan
  • Prepare – Equipment, Medications, etc.
  • Protect the Cervical Spine
  • Preoxygenation (Before Drug Administration)
  • Pretreatment – Used to Prevent Complications of Airway Manipulation
    • Optional for Select Patients
  • Paralysis and Induction
    • Induction Given BEFORE Paralysis
  • Position and Cricoid Pressure
  • Placement and Proof
  • Postintubation Management

Endotracheal Tube (ETT) Size

  • Average Adult Sizing:
    • Males: 8.0-8.5 mm
    • Females: 7.0-7.5 mm
  • Multiple Formulas Exist for Calculating Size Based on Body Height in Adults
  • Pediatrics: (Age in Years / 4) + 4
    • Can Use the Patient’s Pinky to Estimate Tube Diameter
    • *Short Trachea Makes it Easier to Mainstem

Endotracheal Tube (ETT) Cuff

  • The Cuff is an Inflatable Balloon at the Distal End of the Endotracheal Tube Used to Prevent Aspiration and Prevent Air Leakage, Facilitating Positive Pressure Ventilation
  • The Majority of Endotracheal Tubes are Cuffed
  • Use Uncuffed Tubes in Neonates < 1 Year Old
    • OK to Use Cuffed Tubes in Older Peds
    • *Old Dogma to Not to Use Cuffed Tubes in Pediatrics is Now Forgone Given Newer Tubes with Lower Pressure

Confirmation of Endotracheal Tube Placement

  • Techniques:
    • End Tidal CO2 (ETCO2) – The Gold Standard and Best Determinant
    • Direct Visualization
    • Chest Xray
    • Esophageal Detector Devices
    • Transtracheal US – Can Supplement Patients in Cardiopulmonary Arrest Who May Have Decreased Flow and Falsely Low ETCO2
  • Goal Distance: Tip 2-3 cm Above Carina

Pretreatment

General Indications for Pretreatment

  • High Airway Pressures
  • High Intracranial Pressures (ICP)
  • Select Cardiovascular Conditions
  • *Mnemonic for Indications for Pretreatment in RSI: “ABC”
    • A: Asthma
    • B: Brain
    • C: Cardiovascular

General Approach

  • High Airway Pressures: Albuterol or Lidocaine
  • High ICP: Fentanyl
  • Cardiovascular Conditions:
    • Prevent Hypertension (Acute Coronary Syndrome or Aortic Dissection): Fentanyl
    • Prevent Hypotension (Shock): Vasopressors

Medications

  • Aerosolized Beta-2 Agonist (Albuterol)
    • If Presenting with Acute Bronchospasm
  • Lidocaine
    • Reduce Risk of Bronchospasm if a Beta-2 Agonist is Not Given
    • Dose: 1.5 mg/kg IV Given 3 Minutes Before Induction
      • *120 mg for an Average 80 kg Male
    • Onset of Action: 45-90 Seconds
    • Contraindication: High-Grade Heart Block – Can Cause Cardiac Arrest
  • Fentanyl
    • Reduce Cardiovascular Effects from Acute Sympathetic Stimulation if Rapid Blood Pressure Rise Would Be Dangerous (High ICP or Cardiovascular Disease)
    • Dose: 1.5-3 mcg/kg IV Given 3 Minutes Before Induction
      • *120-240 mcg for an Average 80 kg Male
  • Vasopressors (Alpha-Adrenergic Agents)
    • Given to Patients in Shock to Maintain Blood Pressure and Attempt to Mitigate the Possible Hypotension After Induction
    • Dose:
      • Epinephrine 5-20 mcg
      • Phenylephrine 50-200 mcg
  • Atropine
    • Used to Prevent Vagally-Induced Bradycardia in Infants (< 1 Year Old)
    • Dose: 0.02 mg/kg IV (Maximum 1 mg)
  • Small (Defasciculating) Dose of Neuromuscular Blocker
    • Was Historically Given Prior to the Use of Succinylcholine to Reduce Rise in ICP from Succinylcholine-Induced Fasciculations
    • No Longer Recommended – No Evidence to Support

Induction Agents

Etomidate

  • GABA Receptor Agonist
  • Dose: 0.3-0.4 mg/kg
    • *24-32 mg for an Average 80 kg Male
  • Advantages: Minimal Cardiovascular Effects
  • Disadvantages: Can Cause Adrenocortical Suppression
    • Primarily Concerned If Given by Long-Term Continuous Infusion and Less So When Given as a Bolus Dose in RSI

Ketamine

  • Noncompetitive NMDA Receptor Antagonist
  • Dose: 1-2 mg/kg
    • *80-160 mg for an Average 80 kg Male
  • Advantages: Stimulates Catecholamine Release, Bronchodilation, and Has No Significant Respiratory Depression
  • Disadvantages: Catecholamine Release Can Cause Tachycardia, Hypertension, and Increased Myocardial Oxygen Consumption
    • Avoid in Severe Cardiac Decompensation (MI or Unstable Angina)
    • Can Also Cause Hallucinations
  • *Historically Contraindicated in TBI Due to Increased Cerebral Blood Flow and ICP – Now Disproven

Midazolam

  • GABA Receptor Agonist
  • Dose: 0.2-0.3 mg/kg – Commonly Underdosed
    • *16-24 mg for an Average 80 kg Male
  • Advantages: Added Amnesic Effects
  • Disadvantages: Respiratory Depression and Hypotension

Propofol

  • GABA Receptor Agonist
  • Dose: 1.5-3 mg/kg
    • *120-240 mg for an Average 80 kg Male
  • Advantages: Bronchodilation and Decreased ICP
  • Disadvantages: Significant Cardiovascular Effects (Hypotension and Bradycardia)

Paralytic Agents

Rocuronium

  • Non-Depolarizing Agent
  • Dose: 1.0-1.2 mg/kg IV
    • *80-96 mg for an Average 80 kg Male
  • Onset of Action: 45-60 Seconds
  • Duration of Action: 45 Minutes
  • Contraindicated if Needing Rapid Recovery (Neuro Assessment or Elective Procedures)

Succinylcholine

  • Depolarizing Agent
  • Dose: 1.5 mg/kg IV
    • *120 mg for an Average 80 kg Male
  • Onset of Action: 45-60 Seconds
  • Duration of Action: 10 Minutes
  • Many Contraindications:
    • Hyperkalemia
    • Burns (> 3-5 Days)
    • Rhabdomyolysis
    • Malignant Hyperthermia
    • Neuromuscular Disease

*Most Other Paralytic Drugs Have Too Delayed an Onset of Action for RSI

Laryngoscopy

Direct Laryngoscopy: Use of a Laryngoscope to Directly Visualize the Vocal Cords for Endotracheal Intubation

Indirect Laryngoscopy: Examination of the Larynx without a Direct Ling-of-Sight (Ex: Using Light and Small Tilted Mirrors) – Used for Diagnostics and Not for Endotracheal Intubation

Video Laryngoscopy: Use of Fiberoptic Videoscopic Guidance to Allow Better Visualization of the Vocal Cords for Endotracheal Intubation

Levitan Approach

  • Position and Preparation
  • Identify the Epiglottis
  • Laryngeal Exposure
  • Place the Tube

Laryngoscope Blades

  • Macintosh (Mac) Blade
    • Curved Blade with a 90-Degree Handle
    • Tip is Placed in Vallecula (Between the Tongue and Epiglottis)
    • Sizes:
      • Macintosh 3 – The Standard Original Size
      • Macintosh 4 – A Larger Size for Bigger Patients
      • Macintosh 1 and 2 – Smaller Sizes for Pediatric Patients
    • Mac is the Most Commonly Used Blade
  • Miller Blade
    • Straight Blade with Curved Tip
    • Tip is Placed Under the Epiglottis
  • Other Less Commonly Used:
    • Kessel – Curved with 110-Degree Handle
    • McCoy – Curved with a Flexible Distal Tip

Video Laryngoscopy

  • Fiberoptic Videoscopic Guidance Allows Better Visualization
  • Some Consider it to be “Standard of Care” – Heatedly Debated
  • Examples: GlideScope, Storz C-Mac, etc.

Laryngoscope Blades: (A) Mac 1, (B) Miller 2

Rescue Techniques

Cricoid Pressure (Sellick Maneuver)

  • External Digital Pressure Applied to the Cricoid Cartilage
  • May Prevent Passive Regurgitation of Gastric Contents (No Real Evidence)
  • Generally Does Not Assist is Visualization
    • May Actually Inhibit View and Compress the Airway, Blocking Tube Passage

Video Laryngoscopy

  • Fiberoptic Videoscopic Guidance to Allow Better Visualization
  • Can Be Used as a Rescue Technique if Not Already Using as the Primary Technique for Intubation

Flexible Bougies

  • Bent Thin Semi-Rigid Stylette that is Easier to Place Initially than a Larger Endotracheal Tube
  • Placement:
    • Bougie is First Placed Through the Cords into the Trachea
    • Produces “Washboard Effect” as it Rubs Against Tracheal Rings to Confirm Placement
    • Endotracheal Tube Then Advanced Over the Bougie into Place

Laryngeal Mask Airway (LMA)

  • Elliptical Cuff with Tip Occluding the Esophagus
  • Creates Low Pressure Seal Around the Larynx
  • Not a Definitive Airway Protection and Does Not Ensure Patency

Combitube

  • Dual Lumen Esophagotracheal Tube
    • One Tube in Esophagus
    • One Tube in Trachea
  • May Be Helpful in Select Circumstances

Emergency Cricothyroidotomy

  • *See Cricothyroidotomy
  • Contraindicated for Pediatrics Under Age 10-12 Years
    • *Instead Consider Needle Cricothyroidotomy

References

  1. Macintosh Blades. Sasata. Wikimedia Commons. (License: CC BY-3.0)
  2. Miller Blades. DiverDave. Wikimedia Commons. (License: CC BY-3.0)