In advanced airway management, rapid sequence induction (RSI) – also referred to as rapid sequence intubation or as rapid sequence induction and intubation (RSII) or as crash induction – is a special process for endotracheal intubation that is used where the patient is at a high risk of pulmonary aspiration. It differs from other techniques for inducing general anesthesia in that several extra precautions are taken to minimize the time between giving the induction drugs and securing the tube, during which period the patients airway is essentially unprotected.First described by William Stept and Peter Safar in 1970, "classical" or "traditional" RSI involves pre-filling the patients lungs with a high concentration of oxygen gas; applying cricoid pressure to occlude the esophagus; administering pre-determined doses of rapid-onset sedative and neuromuscular-blocking drugs (traditionally thiopentone and suxamethonium) that induce prompt unconsciousness and paralysis; avoiding any artificial positive-pressure ventilation by mask after the patient stops breathing (to minimize insufflation of air into the stomach, which might otherwise provoke regurgitation); inserting a cuffed endotracheal tube with minimal delay; and then releasing the cricoid pressure after the cuff is inflated, with ventilation being started through the tube. There is no consensus around the precise definition of the term "modified RSI", but it is used to refer to various modifications that deviate from the classic sequence – usually to improve the patients physiological stability during the procedure, at the expense of theoretically increasing the risk of regurgitation.
Drug Information Portal. U.S. National Library of Medicine. "Umbralisib". NCI Drug Dictionary. National Cancer Institute.