Basic Airway Adjuncts & Bag Mask Ventilation: Study Guide

Basic Airway Adjuncts & Bag Mask Ventilation

Introduction

This guide covers the essential concepts and procedures related to basic airway adjuncts and bag mask ventilation, which are foundational skills in airway management for respiratory therapy, emergency medicine, and critical care. Understanding these techniques is crucial for maintaining airway patency and providing effective ventilation in patients with compromised airways.

Head Tilt-Chin Lift vs. Jaw Thrust

Airway Positioning Techniques

• Head Tilt-Chin Lift: Used to open the airway in patients without suspected cervical spine injury. The head is extended and the chin lifted to prevent the tongue from obstructing the airway.

• Jaw Thrust: Preferred when cervical spine injury is suspected. The mandible is lifted forward without moving the neck, maintaining spinal precautions.

• Sniffing Position: The external ear canal should be aligned with the anterior aspect of the shoulder while the head is extended. This optimizes airway patency.

• Avoid Extreme Hyperextension: Overextension can worsen airway obstruction or cause injury.

Example: Use the jaw thrust in trauma patients with possible neck injury; use head tilt-chin lift in non-trauma, unconscious patients.

Airway Adjuncts

Definition and Purpose

• Airway adjuncts are devices designed to prevent the tongue from occluding the airway, thereby providing an open conduit for air to pass.

• They are essential in maintaining airway patency, especially in unconscious or semi-conscious patients.

Artificial Airway Adjuncts

Indications

• Relief of airway obstruction

• Facilitation for suctioning

• Some protection of the airway

Oral & Nasal Pharyngeal Airway Adjuncts

Types and Uses

• Oropharyngeal Airway (OPA): Inserted through the mouth to prevent the tongue from blocking the pharynx.

• Nasopharyngeal Airway (NPA): Inserted through the nose to maintain airway patency, especially when the mouth cannot be opened.

Indications for Use

• Facilitate and maintain upper airway patency in conjunction with head positioning

• Prevent airway obstruction from a flaccid tongue

• Establish a route to apply suctioning

• Prevent obstruction by lips and teeth

• Facilitate bag-mask ventilation

Oropharyngeal Airway Placement and Facts

Key Points

• Never use on a conscious patient (may trigger gag reflex and vomiting).

• Remove airway if gag reflex is present.

• Insert inverted, past base of tongue, then rotate into position in the oropharynx.

• May be passed over the tongue using a tongue depressor.

• Never force placement; improper placement can worsen obstruction.

• Determine proper size by measuring from the central incisors to the angle of the mandible.

Nasopharyngeal Airway Placement and Facts

Key Points

• Can be inserted in semiconscious or conscious patients who cannot tolerate an oropharyngeal airway.

• Inserted through the nostril; tip should lay in the posterior pharynx just above the epiglottis.

• Useful in patients with clenched jaws or oral trauma.

• Proper size: measure from the tip of the nose to the earlobe or angle of the jaw.

Types of Nasopharyngeal Airways

• Rusch

• Bardex

• Argyle

• Saklad (Murphy eye)

Bag Mask Ventilation

Equipment and Technique

• Bag Mask Unit: Used to provide positive pressure breaths; with oxygen source, can deliver up to 100% oxygen.

• Mask sizing: should extend from the bridge of the nose to the chin.

• Position yourself directly above the victim's head for optimal control.

• Apply the "E-C Clamp" technique to ensure a good seal.

• Two-person technique is preferred for better seal and ventilation.

Positive Pressure Breaths

• Squeeze bag over 1 second to deliver breath.

• Half squeeze of adult size bag delivers approximately 500-600 mL.

Indications and Contraindications

Indications

• Cardiopulmonary arrest

• Respiratory arrest (apnea)

• Spinal cord or head injuries

• Drug overdose

• Respiratory insufficiency (e.g., myocardial infarction, shock, pulmonary edema, anaphylaxis, smoke inhalation)

Contraindications

• Known, signed, and witnessed Do Not Resuscitate (DNR) order

• CPR determined to be futile due to terminal condition

Hazards of Manual Resuscitation

• Unrecognized equipment failure

• Gastric distention with mask ventilation

• Pulmonary barotrauma/volutrauma

• Hyperventilation

Unrecognized Equipment Failure

• Check device before use: occlude patient connection, compress bag, check for resistance and leaks.

• Common failures: valve malfunction, foreign body obstruction.

Gastric Distention

• Occurs with excessive inspiratory flow or volume.

• Minimize by delivering breath over 1 second in adults.

• Best avoided with a cuffed endotracheal tube.

Barotrauma/Volutrauma

• High risk in small children and infants; adult bags should not be used on pediatric patients.

• Pressure relief valves (set to 35-40 cmH2O) help prevent excessive pressure.

• Monitor with a pressure manometer if available.

Pressure Relief Valves

• Pop-off valves open when pressure exceeds set limit, venting excess gas to atmosphere.

• Primarily used in pediatric ventilation.

Hyperventilation

• Avoid excessive ventilation to prevent increased intrathoracic pressure, decreased venous return, decreased cardiac output, and reduced survival.

• During CPR, ventilate at prescribed rates:

  • 30:2 ratio during CPR without advanced airway

  • 1 breath every 6 seconds with advanced airway

  • Rescue breathing: 1 breath every 5-6 seconds (adult), 1 breath every 3-5 seconds (pediatrics)

Monitoring Effectiveness of Ventilation

• Watch for visible chest rise with each breath.

• Wait for chest to return to resting position before delivering next breath.

• Monitor vital signs: oxygen saturation, exhaled CO2, heart rate, blood pressure, and patient response.

Summary Table: Airway Adjuncts Comparison

Adjunct Type	Insertion Route	Indications	Contraindications	Special Notes
Oropharyngeal Airway (OPA)	Mouth	Unconscious, no gag reflex	Conscious, intact gag reflex	Measure from incisors to angle of mandible
Nasopharyngeal Airway (NPA)	Nose	Semi-conscious, clenched jaw, oral trauma	Basilar skull fracture, severe nasal trauma	Measure from nose to earlobe

References & Further Study

• NEJM Video: Bag Mask Ventilation Demonstration