Advanced Airway Management Notes

Overview

• Deliver safe, patient-focused care by being well-trained.
• Involve anesthesia/critical care early in the patient’s resuscitation.
• Maintain the required equipment needed with experienced emergency physicians (EP) and well-trained clinicians.

Introduction

• As anesthesia and technology advance, more powerful techniques and more complicated equipment are utilized for airway management.
• Early equipment was rudimentary, but modern equipment provides clinicians with sophisticated and versatile methods of ventilation and intubation.

Risks in Critically Ill Patients

• Patient factors may preclude standard airway assessment in critically ill patients.
• Urgency and reduced physiological reserve increase risks of:
  • Profound peri-intubation hypoxemia
  • Hypotension
  • Arrhythmia
  • Cardiac arrest
  • Death
• Delays during tracheal intubation and multiple attempts at laryngoscopy are associated with increased complications, including cardiac arrest and death.

Teamwork and Non-Technical Skills

• Communication is key to successful management of stressful and difficult situations.
• While urgent, few clinical staff are required immediately.
• Utilize the range of experience within the team to deliver safe, patient-focused care.
• Stay calm, optimize what you can, and have a plan B if needed.

Assistance

• Resuscitation room nurses are competent in providing cricoid pressure and assisting with intubation.
• Operating Department Practitioners should routinely attend (ED) and Rapid Sequence Induction (RSI) if available.
• They may support competent nursing staff or take a more active role in anticipated or encountered difficult airways.

Management of Anticipated Difficult Airways

• If difficulty is anticipated, potential actions include:
  • Maintain oxygenation and ventilation via other means (e.g., basic maneuvers/adjuncts).
  • Call for additional anesthetist/technicians/surgical help.
  • Summon the difficult airway trolley from theaters.
  • Move the patient to an operating theater.

Management of Unanticipated Difficult Airways

• If an unanticipated difficult airway is encountered, the Difficult Airway Society (DAS) algorithm should be the default approach.
• Positioning should be optimized for all patients.
• McGrath video laryngoscopes are available in every airway trolley in the ED for trained individuals.
• Consider routine use of a gum elastic bougie.
• Gentle ventilation prior to intubation is safe.
  • Patients receiving bag-mask ventilation had higher oxygen saturations and a lower incidence of severe hypoxemia than those receiving no ventilation.
• "Nasal oxygen during efforts to secure a tube": simple nasal cannulae with $10l/min$ $O_2$ can be administered beneath the facemask during preoxygenation and remain in place during BMV and laryngoscopy.
• High Flow Nasal Oxygen (HFNO) can be delivered using the ED’s V60 ventilator.
• In the event of difficult view at laryngoscopy consider early release.
• Post-intubation checks should include careful cuff inflation and careful securing of the ETT.

Documentation and Daily Routines

• Airway management and transfers must be documented to theatre standard (anesthetic forms are available in the ED).
• Suction Above Cuff Endotracheal Tube:
  • Reduces the risk of ventilator-associated pneumonia and should be used for all patients being intubated in the ED.
  • A size 8.0 tube is preferable, but consider a size 7.0 for smaller adults.
• Capnography:
  • Use of waveform capnography is mandatory for all endotracheal intubations.
  • Remember “No trace wrong place”: even in low cardiac output states and cardiac arrest, should be able to see a waveform.

Special Circumstances

Trauma

• Oxygenation and airway maintenance remain the priority.
• If the cervical spine is not ‘cleared’:
  • Remove the collar prior to RSI.
  • Apply manual in-line stabilization (MILS) and aim to minimize movement.
  • Laryngeal view is likely to be at least one grade worse owing to suboptimal positioning.
• Patients with facial injuries may be better managed sitting up to allow airway maintenance and postural drainage.
• RSI may precipitate cardiovascular compromise (induction agents and positive airway pressure);
  • Consider adequacy of volume resuscitation, timing/location of intervention, and doses of induction agents.

Pregnancy

• Inform the obstetric anesthetics trainee and consultant in addition to the on-call anesthetist.

Obesity

• Anticipate difficulty and rapid desaturation.
• Ramp, consider using Oxford HELP pillows.
• Induction doses should be based on ideal weight; height in centimeters.

Laryngectomy / Tracheostomy

• Double lumen tubes (DLTs) may be required.

Supra and Infraglottic Devices

• Supraglottic devices: are alternative devices to ensure airway patency by bridging the oral/pharyngeal space and to allow both positive pressure as well as spontaneous ventilation.
  • Ideally, they produce low resistance to respiratory gas flow and protect the respiratory tract from gastric and nasal secretions.

Laryngeal Mask Airway (LMA)

• Developed by British Anesthesiologist Dr. Archi Brain.
• Initially designed for use in the operating room as a method of elective ventilation.
• A good alternative to bag-valve-mask ventilation.
  • Frees the hands of the provider with the benefit of less gastric distention.
• Has come into use in the emergency setting as an important accessory device for management of the difficult airway.
• Shaped like a large endotracheal tube on the proximal end that connects to an elliptical mask on the distal end.
• Designed to sit in the patient’s hypopharynx and cover the supraglottic structures, thereby allowing relative isolation of the trachea.
• The patient should be obtunded and unresponsive before one of these devices is placed.

Indications

• Elective surgical procedures requiring general anesthesia with spontaneous or controlled ventilation.
• Difficult airway management and rescue airway situations.
• Pre-hospital and emergency settings for rapid airway management.
• Short-duration procedures where intubation is not necessary.

I-gel airways

• The I-gel is a relatively new supraglottic airway.
• The cuff is made of thermoplastic elastomer gel and does not require inflation.
• The stem of the i-gel incorporates a bite block and a narrow oesophageal drain tube.
• It is easy to insert, requiring only minimal training and a laryngeal seal pressure of $20 - 24 cmH_2O$ can be achieved.
• Insertion of the i-gel was significantly faster than several other airway devices in manikin studies.
• The ease of insertion of the i-gel and its favorable leak pressure make it theoretically very attractive as a resuscitation airway device for those inexperienced in tracheal intubation.

Laryngeal tube

• The laryngeal tube (LT) is another of the new supraglottic airway devices that have been developed.
• It is a single lumen tube with both an esophageal and pharyngeal cuff.
• A single pilot balloon inflates both cuffs simultaneously and it is available in a variety of sizes.
• Successful insertion and airway pressures generated are comparable to the LMA when performed by non anesthetists.
• There are several observational studies that document successful use of the LT by nurses and paramedics during prehospital cardiac arrest.
• A double lumen LT with an esophageal vent and a disposable version (LT-D) are available

Cobra Perilaryngeal Airway (PLA)

• The CobraPLA is a cuffed, pharyngeal sealer, supraglottic airway which is disposable, sterile, and latex-free
• The construction of it consists of a head containing slotted openings to hold both the soft tissue and epiglottis away and permit air exchange, a circumferential pharyngeal large-volume, low-pressure cuff, and a breathing tube which can be attached to a standard 15 mm ID connector.

Infraglottic Devices

Combitube

• The Combitube or esophagotracheal Combitube is a variation of the esophageal obturator airway that may be useful in the event of a difficult intubation or the “can’t intubate, can’t ventilate” situation.
• It is also increasingly used in clinical anesthesiology where endotracheal intubation is contraindicated.
• The Combitube is a double-lumen tube with an open distal end on the longer lumen and eight small perforations at the supraglottic level of the second lumen, which has a blind end.
• No preparations are required for intubation, although a laryngoscope is recommended for experienced users during.

Laryngoscope types, Handles and Blades

• Handles
• Blades
• Left-Handed Macintosh Blade
• Fiberoptic Laryngoscopes
• Video laryngoscopes
• Stylets and Light Wands

Endotracheal Tubes

• There is a great variety of endotracheal tubes to choose from.
• There are many special types of endotracheal tubes—articulating; armored, or wire-reinforced; double-lumen endobronchial, polar, and uncuffed.

Articulating

• The Endotrol has the appearance of a regular endotracheal tube, containing a high-volume, low-pressure cuff, but is equipped with a “built-in” stylet.
• When its “trigger,” or ring, is pulled, a thread running through a channel in the tube wall applies traction to the tip of the tube, causing the tube curvature to increase.

Armored or Wire-Reinforced

• The wire-reinforced tubes are manufactured with a spiral of metal wire or nylon filament embedded into their wall to prevent kinking or occlusion of the tube when the head or neck is moved.
• The tube can be used orally, nasally, or through a tracheostomy stoma.
• The external diameter will be larger than ordinary tube of similar size.
• Certain manufacturers do not incorporate a bevel or Murphy eye in its tube design.
• Use of a reinforced tube is indicated when the patient’s head is in an extended or flexed position, when the patient will be turned over, or during neurosurgical or head and neck procedures.

Double-Lumen Endobronchial

• A double-lumen endobronchial tube is used when differential or selective