Editing Tracheal intubation (section)

===Hypoxemia===
Intubation may be necessary for a patient with [[hypoxemia|decreased oxygen content]] and [[oxygen saturation]] of the blood caused when their breathing is inadequate ([[hypoventilation]]), suspended ([[apnea]]), or when the lungs are unable to sufficiently [[diffusion capacity|transfer gasses to the blood]].<ref>{{cite web |last1=Mallinson |first1=Tom |last2=Worrall |first2=Mark |last3=Price |first3=Richard |last4=Duff |first4=Lorna |date=2022 |title=Prehospital endotracheal intubation in cardiac arrest by BASICS Scotland clinicians |url=https://rgdoi.net/10.13140/RG.2.2.24988.56969 |language=en |doi=10.13140/RG.2.2.24988.56969}}</ref> Such patients, who may be awake and alert, are typically critically ill with a multisystem disease or [[Polytrauma|multiple severe injuries]].<ref name=Ezri2007/> Examples of such conditions include [[Spinal cord injury|cervical spine injury]], [[flail chest|multiple rib fractures]], severe [[pneumonia]], [[acute respiratory distress syndrome]] (ARDS), or near-[[drowning]]. Specifically, intubation is considered if the [[arterial blood gas|arterial]] [[partial pressure]] of oxygen (PaO<sub>2</sub>) is less than 60&nbsp;[[Torr|millimeters of mercury]] (mm Hg) while breathing an inspired O<sub>2</sub> concentration ([[FiO2|FIO<sub>2</sub>]]) of 50% or greater. In patients with [[Hypercapnia|elevated arterial carbon dioxide]], an arterial partial pressure of CO<sub>2</sub> (PaCO<sub>2</sub>) greater than 45&nbsp;mm Hg in the setting of [[Acidosis|acidemia]] would prompt intubation, especially if a series of measurements demonstrate a worsening [[respiratory acidosis]]. Regardless of the laboratory values, these guidelines are always interpreted in the clinical context.<ref name=Holcroft2010/>