Prehospital Academy Lesson 11.9
Blind Insertion and Supraglottic Airway Devices (BIAD, SGAD)
Introduction: Essential Tools for Prehospital Airway Management
In the dynamic and often chaotic environment of prehospital emergency care, securing a patient's airway is paramount. While endotracheal intubation (ETI) remains the gold standard for definitive airway control, situations often arise where it is not feasible or appropriate. This is where Blind Insertion Airway Devices (BIADs), also known as supraglottic airway devices (SGAs), become invaluable. These devices are designed for rapid placement without direct visualization of the vocal cords, facilitating effective ventilation and oxygenation.
Types of Blind Insertion Airway Devices
A variety of BIADs are available for use in the prehospital setting, each with its unique design and application:
iGel: A single use Laryngeal Mask type airway used to assist ventilations.
King Laryngeal Tube (King LT): Highly popular in EMS, the King LT is an uncuffed, single-use, dual-lumen device. It features two balloons that, once inflated, seal the esophagus and the oropharynx, directing ventilations into the trachea. It's known for its ease of insertion and effectiveness.
Laryngeal Mask Airway (LMA): The LMA consists of an inflatable mask that forms a seal around the laryngeal inlet. It is available in various sizes and is a common choice for both prehospital and in-hospital airway management.
Combitube: This is a double-lumen tube that can function whether placed in the esophagus or the trachea. Its unique design allows for ventilation regardless of its distal tip's placement.
Indications for BIAD Use in EMS
BIADs are critical for effective airway management in a range of emergency situations, especially when rapid airway control is required and ETI attempts are difficult or unsuccessful. Key indications include:
*Important note: BIADs and SGAs, do NOT protect a patients airway from aspiration.
Emergency Airway Management: Whenever a patient's airway is compromised and rapid intervention is necessary.
Failed Endotracheal Intubation: BIADs serve as a crucial rescue device when attempts at ETI are unsuccessful, preventing prolonged periods of hypoxia.
Difficult Airway Scenarios: In situations where anatomical challenges or environmental factors (e.g., poor lighting, confined spaces) make direct laryngoscopy difficult.
Cardiac Arrest: BIADs are often preferred during cardiac arrest because they are generally faster and easier to insert than ETI, minimizing interruptions to chest compressions.
Respiratory Failure or Arrest: To provide immediate ventilation and oxygenation in patients with severe respiratory compromise or apnea.
Altered Consciousness: In patients with a decreased level of consciousness who cannot maintain or protect their own airway.
Contraindications for BIAD Application
Despite their utility, BIADs are not suitable for all patients. It is essential to recognize specific contraindications to prevent adverse outcomes:
Intact Gag Reflex: The presence of an intact gag reflex can lead to vomiting, increasing the risk of aspiration.
Known or Suspected Upper Airway Obstruction: BIADs may worsen an existing upper airway obstruction.
Caustic Ingestion: In cases of corrosive substance ingestion, insertion of a BIAD could cause further esophageal trauma.
Tracheal Injury or Pathology: Conditions affecting the trachea may contraindicate BIAD use.
Pediatric Considerations: Some BIADs are not available in appropriate pediatric sizes, or their effectiveness may be limited in very small children.
Severe Facial Trauma: Depending on the extent and location of facial injuries, some BIADs may be difficult to seat properly or could exacerbate trauma.
Insertion and Confirmation of Placement
Proper insertion technique and rigorous confirmation of placement are vital for the safe and effective use of BIADs:
Preparation: Select the appropriate size device, lubricate it, and ensure all components are functional.
Patient Positioning: Position the patient's head and neck to optimize airway alignment, typically in a neutral or sniffing position depending on the device.
Insertion: Follow manufacturer guidelines for insertion. For devices like the King LT, this often involves inserting the device with a lateral rotation and then rotating it back to midline as it advances into the oropharynx.
Cuff Inflation: Inflate the cuff(s) with the recommended volume of air.
Confirmation: Crucially, confirm proper placement immediately after insertion. This involves:
Observing chest rise and fall.
Auscultating for bilateral breath sounds over the lungs and absence of gastric sounds.
Utilizing quantitative waveform capnography – this is the most reliable method for confirming tracheal placement and is strongly encouraged.
Securing the Device: Once confirmed, secure the BIAD to prevent dislodgement during patient movement.
Advantages in the Prehospital Environment
BIADs offer several advantages that make them particularly well-suited for EMS:
Ease and Speed of Insertion: They generally require less training and are quicker to insert than ETI, which is critical in time-sensitive emergencies.
Reduced Interruption of CPR: Rapid insertion means less time off the chest during cardiac arrest resuscitation.
Versatility: Effective in a wide range of clinical scenarios and patient presentations.
Critical Thinking Questions
You respond to a patient in cardiac arrest. After failed attempts at bag-mask ventilation, you decide to insert a King LT. Describe the steps you would take to insert and confirm the placement of this device.
A patient with a suspected C-spine injury requires advanced airway management. Which BIAD would be most appropriate, and what modifications to insertion technique might be necessary?
A patient with an intact gag reflex is experiencing severe respiratory distress. Would a BIAD be an appropriate intervention? Why or why not? What alternatives might you consider?
Compare and contrast the advantages and disadvantages of using a BIAD versus endotracheal intubation in the prehospital setting for a patient in respiratory arrest.
During transport, your patient's SpO2 begins to drop after a BIAD has been placed. What are your immediate troubleshooting steps, and what potential complications should you consider?