Process of breathing includes ventilation of the lungs , gaseous exchange between the lungs and blood, transport of gases (oxygen and carbon dioxide) in the blood and exchange of gases between the blood and tissue. The principal organs of the respiratory system are the nose, pharynx, larynx, trachea, bronchi and lungs. Resources for maintenance of airway in medicine are: ventilation mask, oropharynegeal tube, nasopharyngeal tube, bag-valve-mask ventilation and supraglottic maintenance as laryngeal mask and I-gel tubus. Rapid sequence intubation (RSI) is a procedure that applies rapid application of sedatives and paralytic agents to facilitate endotracheal intubation and to prevent the risk of aspiration of the gastric contents. Procedure of RSI protocol consists of several steps: preparation, preoxygenation, pretreatment, paralysis with induction, protection and positioning, placement of the endotracheal tube and post intubation management. The drugs used in the rapid sequence intubation protocol are lidocaine, atropine and fentanyl used in the premedication process, and the drugs used in induction are: short-acting barbiturates, thiopental and methohexital, benzodiazepines (midazolam), and other drugs such as etomidate, ketamine and propofol. Neuromuscular blocking agents commonly used are succinylcholine and rocuronium.