Chapter 13: Airway Management

INTRODUCTION

Securing the airway is an important task for treating critically ill patients. Indications for endotracheal intubation include surgical procedure, respiratory failure, cardiac arrest, airway protection (ie, coma), and airway obstruction (ie, anaphylaxis, airway burns, airway bleeding).

For any patient undergoing surgery, preoperative assessment includes American Society of Anesthesiologists Classification (ASA) which assesses the physiologic status to predict operative risk.¹ ASA 1 is a normal healthy patient with good exercise tolerance.¹ ASA 2 is patient with mild systemic disease that is well controlled and no functional limitation.¹ ASA 3 is a patient with severe systemic disease that is not life threatening with some functional limitation.¹ ASA 4 is severe disease with a constant threat to life.¹ ASA 5 is a patient with is not going to survive without surgery.¹ ASA 6 is a brain dead patient for organ harvest.¹

For any patient requiring a secure airway, difficult intubation, defined as difficult facemask or supraglottic airway (SGA) ventilation, difficult supraglottic airway placement, difficult laryngoscopy, difficult tracheal intubation, or failed intubation attempts, should be anticipated.² Avoidance of “can’t intubate can’t oxygenate” situation or CICO is paramount. The ASA have released guidelines based on levels of evidence.² Recommendation for Category A has 3 levels: Level 1 has sufficient randomized control trials to conduct meta-analysis; Level 2 has multiple randomized control trials but not sufficient for meta-analysis; and Level 3 has a single randomized control trial.² Recommendation for Category B also has 4 levels: Level 1 has observational studies with clinical interventions for a specific outcome; Level 2 has observational studies with associative statistics; Level 3 has noncomparative observational studies with descriptive statistics; and Level 4 has case reports.² Based on the Fourth National Audit Project (4NAP), the following were associated with airway complications: human factors such as poor education and judgment; omission of airway assessment; poor planning; intubation failure managed with repeated attempts; obese patients; use of supraglottic devices on poor candidates such as obese patients or high risk for aspiration; delay for emergent front of neck airway; unrecognized esophageal intubation; failure to use capnography; and recovery events such as blood in airway, tracheal edema, or postobstructive pulmonary edema (POPE).^3-5 The Royal Academy of Anesthesiologists and Difficult Airway Society Guidelines are stratified into 4 plans.^6,7 Plan A is preparation, oxygenation, induction, mask ventilation, and intubation.^6,7 Plan B is rescue airway via supraglottic device.^6,7 Plan C is final attempt at preoxygenation via facemask ventilation.^6,7 Plan D is emergent front of neck airway or eFONA.^6,7 These societies advocate the Vortex Approach where a maximum of 3 attempts at oxygenation via supraglottic airway (SGA), facemask, or tracheal intubation.⁶ Further clinical deterioration or failure at all attempts mandates eFONA.⁷

Assessment

Initial airway assessment involves identifying patients ...