Intubation with RSI technique. RSI technique includes the administration of inductive and neuromuscular blocking agents to facilitate an intubation.

In this study, we have no restriction of medication use. Physicians can chose any of medication as an individual judgement.

Intubation without RSI technique. No any medication use during intubation period.

All medications are administered only one dose before intubation

Anesthetics:

Propofol 2-2.5 mg/kg Thiopental 3-5mg/kg Etomidate 1-2mg/kg

Neuromuscular blocking agents:

Succinylcholine 1-1.5mg/kg Rocuronium 0.9mg/kg

Opioid:

Fentanyl 1-2ug/kg

The overall intubation duration is recorded on the decision to intubation patient and corresponds to the time of confirmation the endotracheal position by chest auscultation

The intubation duration (Ti), it is defined from application the laryngoscope into the patient's mouth to the time of confirmation an endotracheal position