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Batterjee Medical College - Airway Management Routes

Definition of Artificial Airways

  • Artificial Airways: Specialized medical devices designed to maintain a patent or open airway.

    • An artificial airway refers to a medical technique or tool applied to maintain an open (patent) airway for individuals unable to do so due to various reasons.

Indications for Use of Artificial Airways

  • Relief of Airway Obstruction: Enables the clearing of obstructed airways.

  • Protecting or Maintaining an Airway: Ensures airway remains open to prevent asphyxiation.

  • Facilitation of Tracheobronchial Clearance: Aids in clearing secretions from the trachea and bronchi.

  • Facilitation of Artificial Ventilation: Essential for providing mechanical ventilation in patients who cannot breathe adequately.

Hazards of Artificial Airways

  • Infection: Occurs because artificial airways bypass the normal defense mechanisms, leading to bacterial contamination.

  • Ineffective Cough Maneuver: Patients may be unable to effectively clear secretions.

  • Impaired Verbal Communication: Patients may struggle to communicate due to the airway device.

  • Loss of Personal Dignity: Patients might feel undignified due to the presence of artificial airways.

Bag Valve Mask Device (BVM)

Overview

  • Other names: Manual Resuscitator, AMBU Bag, Self-Inflating Bag.

  • Available in varying capacities:

    • Adult: 2L (for patients >20kg)

    • Pediatric: 500 ml (for patients 7-20kg)

    • Neonates: 250 ml (for patients <7kg)

  • Types of BVM:

    • Self-inflating Bag: inflates on its own using ambient air.

    • Flow-inflating Bag: requires a continuous oxygen source to inflate.

Working Principle of BVM

  1. Components:

    • Air Inlet: Allows for entry of oxygen.

    • Oxygen Inlet: For connecting the oxygen supply.

    • Patient Outlet: Where air is delivered to the patient.

    • Valve Assembly: Controls the flow of air.

    • Pressure-Release Valve: Prevents overinflation.

    • Oxygen Reservoir: Collects supplemental oxygen.

    • Pressure Manometer Attachment Site (optional): For measuring pressure.

Characteristics of BVM Types

Free Flow BVM

  • Usage: More challenging for beginners; requires a free-flowing oxygen source and a good mask fit for effective ventilation.

  • Features: Provides 100% FiO2; fine control over tidal volume; allows assessment of lung compliance and respiratory effort.

Self-Inflating BVM

  • Usage: Easier for beginners; self-inflates with room air.

  • Features: Limited to a maximum FiO2 of 60% unless a reservoir is used; poor fit may entrain room air. More forgiving with poor mask fit; does not provide feedback on lung compliance or patient effort.

Comparison of Self-Inflating vs. Free Flow BVM

  • Self-Inflating Bag:

    • Easier for beginners.

    • Self-inflates with room air.

    • Can mask seal poorly, leading to entrainment of room air, thus lowering FiO2.

    • Less feedback on lung compliance and tidal volume delivery.

  • Free Flow Bag:

    • Requires a free-flowing oxygen source and proper fitting.

    • Always delivers 100% of FiO2 and provides feedback on lung compliance and patient effort.

Routes for Establishing an Artificial Airway

  • Pharyngeal Airways: Extend only into the pharynx.

  • Endotracheal Tubes: Inserted through the mouth or nose straight into the trachea.

    • Intubation: Process of placing an artificial airway.

    • Orotracheal Intubation: Tube passed through the mouth into the trachea.

    • Nasotracheal Intubation: Tubing inserted through the nose then into the trachea.

Pharyngeal Airways

Types and Uses

  • Nasal Pharyngeal Airway: Facilitates frequent nasotracheal suctioning; minimizes nasal mucosa damage.

  • Oral Pharyngeal Airway: Designed for unconscious patients to prevent tongue obstruction.

    • Can be used as a bite block for patients with oral tubes.

Insertion of Nasopharyngeal Airway

  • Best for patients requiring frequent suctioning, e.g., after extubation.

  • Length is estimated from the earlobe to the tip of the nose.

  • Insertion Steps:

    1. Head tilted back slightly.

    2. Lubricate with a water-soluble agent.

    3. Insert perpendicular to face through the chosen nasal cavity.

    4. If resistance occurs, try another naris or a smaller tube.

    5. Stabilized by its flange once correctly placed.

Oropharyngeal Airways

  • Inserted into the mouth to prevent tongue obstruction; restricted for unconscious patients due to gag reflex.

  • The Guedel airway has a center channel, while the Berman airway has two parallel side channels.

Choosing the Correct Size of Airway

  • Measure from the corner of the patient's mouth to the angle of the jaw to select the appropriate size.

Techniques to Insert an Oropharyngeal Airway

Method 1

  1. Displace the tongue with a tongue depressor.

  2. Slip the airway over the tongue, following the oral cavity's curve.

Method 2

  1. Use the jaw-lift technique to displace the tongue.

  2. Rotate the airway 180 degrees before inserting, so it aids in separating the tongue from the pharynx as it is inserted.

Tracheal Airways

Types of Tracheal Airways

  • Endotracheal Tubes: Inserted through mouths or nose into the trachea.

  • Tracheostomy Tubes: Inserted through a surgically created opening in the neck directly into the trachea.

Reference

  • Egan's Fundamentals of Respiratory Care, 12th edition, Chapter 37, Page 749.