A – protection and patency (e.g. against aspiration or relief of upper airway obstruction as in anaphylaxis or head and neck trauma)
B – respiratory failure (hypercapnic or hypoxic), increase FRC, decrease WOB, secretion management/ pulmonary toilet, to facilitate bronchoscopy
C – minimise oxygen consumption and optimize oxygen delivery (e.g. sepsis)
D – unresponsive to pain, terminate seizure, prevent secondary brain injury
E — temperature control (e.g. serotonin syndrome)
Complications
A – CICV, failed intubation, damage at intubation, mouth ulceration and bleeding
B – VAP, VILI, barotraumas, oxygen toxicity, patient ventilator asynchrony
C – decreased RV preload and increased RV afterload, decreased splanchnic blood flow, increased ICP, fluid retention due to decreased Q, decreased renal blood flow
D – neuropsychiatric complications, insomnia, pain, weakness, PTSD