Pre-oxygenation Guidelines

Introduction to Pre-oxygenation

Pre-oxygenation before induction of anaesthesia is strongly recommended to prevent arterial oxygen desaturation during intubation attempts, which significantly reduces morbidity and mortality by extending the safe apnoea time, as recommended by the American Society of Anesthesiologists 1

Pre-oxygenation extends the safe apnoea time from 1-2 minutes to 6-8 minutes before desaturation to SpO₂ <90%, according to the American Heart Association 1
Pre-oxygenation provides additional time for laryngoscopy, tracheal intubation, and airway rescue maneuvers, reducing morbidity and mortality in 30-60% of cases, even in low-risk patients, as stated by the American College of Cardiology and the American Society of Anesthesiologists 1, 2

Tidal volume breathing with 100% oxygen for 3 minutes via tight-fitting facemask is an effective method of pre-oxygenation, as recommended by the British Journal of Anaesthesia 2
CPAP (5-10 cm H₂O) can be used for pre-oxygenation in patients with impaired oxygenation, according to the British Journal of Anaesthesia 3
High-flow nasal oxygen (HFNO) can be used at 30-70 L/min to further extend safe apnoea time, as stated by the British Journal of Anaesthesia 2, 3
Non-invasive ventilation (NIV) with or without PEEP can shorten pre-oxygenation time to achieve FeO2 > 90% in emergency situations and prevent desaturation episodes during intubation in hypoxemic patients, as recommended by the American Society of Anesthesiologists 1

Obese patients require careful consideration during pre-oxygenation due to reduced functional residual capacity (FRC) leading to faster desaturation, and may benefit from a head-up position (25-30° elevation) to increase safe apnea time, as recommended by the American Society of Anesthesiologists 1
Pregnant women experience more rapid desaturation due to decreased FRC and increased oxygen consumption, and should be pre-oxygenated carefully, as recommended by the American College of Obstetricians and Gynecologists 1
Critically ill patients are at higher risk of rapid desaturation and may benefit from non-invasive ventilation for pre-oxygenation, as recommended by the American Society of Anesthesiologists 1

Proper mask seal is crucial for effective pre-oxygenation, as leaks significantly impair pre-oxygenation, and end-tidal oxygen fraction (FeO₂) should be greater than 90% for pre-oxygenation to be considered effective, as stated by the American Society of Anesthesiologists 1
Nasal oxygen at 15 L/min during intubation attempts maintains high oxygen levels in the hypopharynx, as recommended by the British Journal of Anaesthesia 3
Spontaneous ventilation with 100% oxygen for 3-5 minutes with fresh gas flow of 5 L/min is recommended for pre-oxygenation, with alternative methods including vital capacity maneuvers (8 deep breaths of 100% oxygen over 60 seconds), as recommended by the American Society of Anesthesiologists 1

The American Society of Anesthesiologists recommends using the device with which the operator has the highest probability of achieving rapid tracheal intubation on the first attempt, likely a videolaryngoscope for most fully trained operators, and ensuring complete neuromuscular blockade before attempting tracheal intubation to avoid coughing or patient movement 4
The administration of a hypnotic followed by a neuromuscular blocker in rapid succession is recommended, and the duration of laryngoscopy should be as brief as possible, ideally less than 30 seconds, as stated by the American Society of Anesthesiologists 1, 5
Having an alternative plan and equipment for difficult airway management immediately available is crucial, as well as being prepared for unexpected difficulties, and patients at risk for rapid desaturation (obesity, pregnancy, critical illness) should be identified and employ advanced pre-oxygenation techniques, as recommended by the American Society of Anesthesiologists 4, 1

In patients with COVID-19 or other infectious respiratory diseases, the number of people present during intubation should be minimized, and the most experienced operator should plan and perform the tracheal intubation, as recommended by the American Society of Anesthesiologists 6
In pediatric patients or those at risk of rapid hypoxemia, a "modified" or "controlled" rapid sequence is recommended, ventilating with FiO2 0.8 and low peak inspiratory pressure (< 15 cmH2O) as soon as SpO2 falls below 95% to decrease the risk of hypoxemia during and after intubation, as stated by the American Society of Anesthesiologists 5