Editing Rapid sequence induction (section)

==== Preoxygenation ====
The aim of preoxygenation is to replace the nitrogen that forms the majority of the [[functional residual capacity]] with oxygen. This provides an oxygen reservoir in the lungs that will delay the depletion of oxygen in the absence of ventilation (after paralysis). For a healthy adult, this can lead to maintaining a blood [[oxygen saturation]] of at least 90% for up to 8 minutes.<ref>{{cite journal | vauthors = Benumof JL, Dagg R, Benumof R | title = Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine | journal = Anesthesiology | volume = 87 | issue = 4 | pages = 979–982 | date = October 1997 | pmid = 9357902 | doi = 10.1097/00000542-199710000-00034 | s2cid = 27271368 | doi-access = free }}</ref> This time will be significantly reduced in obese patients, ill patients and children. Preoxygenation is usually performed by giving 100% oxygen via a tightly fitting face mask. Preoxygenation or a maximum of eight deep breaths over 60 seconds resulting in blood oxygenation is not different from that of quiet breathing volume for 3 minutes.<ref>{{Cite web | url=http://anesthesiageneral.com/preoxygenation/ | title=Preoxygenation| date=2010-10-04}}</ref>

Newer methods of preoxygenation include the use of a nasal cannula placed on the patient at 15 LPM at least 5 minutes prior to the administration of the sedation and paralytic drugs. High flow nasal oxygen has been shown to flush the nasopharynx with oxygen, and then when patients inspire they inhale a higher percentage of inspired oxygen. Small changes in FiO2 create dramatic changes in the availability of oxygen at the alveolus, and these increases result in marked expansion of the oxygen reservoir in the lungs prior to the induction of apnea. After apnea created by RSI the same high flow nasal cannula will help maintain oxygen saturation during efforts securing the tube (oral intubation).<ref name="pmid28684195">{{cite journal | vauthors = Binks MJ, Holyoak RS, Melhuish TM, Vlok R, Bond E, White LD | title = Apneic oxygenation during intubation in the emergency department and during retrieval: A systematic review and meta-analysis | journal = The American Journal of Emergency Medicine | volume = 35 | issue = 10 | pages = 1542–1546 | date = October 2017 | pmid = 28684195 | doi = 10.1016/j.ajem.2017.06.046 | s2cid = 8624609 }}</ref><ref name="pmid28647137">{{cite journal | vauthors = Pavlov I, Medrano S, Weingart S | title = Apneic oxygenation reduces the incidence of hypoxemia during emergency intubation: A systematic review and meta-analysis | journal = The American Journal of Emergency Medicine | volume = 35 | issue = 8 | pages = 1184–1189 | date = August 2017 | pmid = 28647137 | doi = 10.1016/j.ajem.2017.06.029 | s2cid = 2383170 }}</ref> The use of nasal oxygen during pre-oxygenation and continued during apnea can prevent hypoxia before and during intubation, even in extreme clinical cases.<ref>{{Cite web | vauthors = Levitan R | url=http://www.epmonthly.com/archives/features/no-desat-/ | title=No Desat! | work = Emergency Physicians Monthly | date=9 December 2010 }}</ref>