Rapid Sequence Induction & Intubation (RSII): Indications & considerations
“Full stomach”: ↑ risk of regurgitation, vomiting, aspiration Life-threatening injury or illness requiring immediate or rapid airway control
↓ Gastro- esophageal sphincter competence (elderly, pregnancy, hiatus hernia, obesity)
↑ Intragastric pressure (pregnancy, obesity, bowel obstruction, large abdominal tumors)
Delayed gastric emptying (narcotics, anticholinergics, pregnancy, renal failure, diabetes)
↓ Level of consciousness (drug/alcohol overdose, head injury, trauma or shock state)
Respiratory & ventilatory compromise (i.e., hypoxic or hypercapnic respiratory failure)
Achalasia (esophageal motility disorder resulting in impaired swallowing)
Dynamically deteriorating clinical situation (i.e., trauma)
GI bleed
Impaired airway reflexes
↓ Muscle tone of structures in the airway (i.e., tongue, pharyngeal walls, & soft palate)
Patients who did not stop GLP-1 agonist preoperatively as advised
Impaired clearance of secretions or vomitus
↓ Safe apnea time before hemodynamic decompensation
Unprotected airway
Need for rapidly securing airway while avoiding aspiration & hemodynamic compromise
Rapid sequence intubation (RSI): Simultaneous administration of induction agent (unconsciousness) & neuromuscular blocking agent (paralysis) to achieve intubation conditions (~45-60 seconds after IV push) for rapid control of an emergency airway
Preoxygenation
Deranged physiologic conditions (i.e., hypotension, acidosis, hypoxemia)
Reduced tolerance for
apnea (period with no ventilation or oxygenation)
Pre-oxygenate with high flow O2 (15L) to create a large pulmonary & tissue reservoir of oxygen
↓ Significant oxygen desaturation during apnea
↑ Oxygen saturation on pulse oximetry
Induction
Laryngoscopy & intubation are a potent sympathetic nervous system stimulus
Airway manipulation causes a surge in catecholamines
Paralysis
Visualization & passage of endotracheal tube requires relaxation of vocal cords & surrounding muscles
Neuromuscular blocking agents facilitate paralysis
Rescue
Some induction agents (i.e., propofol) are vasodilators
Hemodynamically unstable or patients in shock
Hypotension
Tachycardia
↑ Intracranial pressure (ICP)
Hypertension
Suppress cough & gag reflex
Prevent laryngospasm (involuntary closure of vocal cords to airway manipulation)
Minimize movement during procedure
Vasoactive agents (i.e., ephedrine, phenylephrine) ↑ systemic vascular resistance
Atropine & glycopyrrolate ↑ heart rate
Lidocaine (Na+ channel blocker) & opioids (μ receptor agonist) ↓ transmission of pain
↓ Sympathetic response, myocardial demand & physiologic stress
Anesthetics (i.e., propofol) achieve unconsciousness for paralysis & intubation
↓ Airway trauma & damage to vocal cords
Bag mask ventilation typically avoided in this step to ↓ gastric insufflation & risk of aspiration
Cricoid pressure (Sellick maneuver): posterior displacement of cricoid ring to compress esophagus against C-spine to prevent passive regurgitation of gastric contents to airway. Applied from start of induction, released when placement of endotracheal tube is confirmed by capnography.
Intubation
↑ Blood pressure and/or cardiac output
Authors: Jen Guo Reviewers: Priyanka Grewa Luiza Radu Leyla Baghirzada* * MD at time of publication
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published November 18, 2024 on www.thecalgaryguide.com