Rapid sequence induction and intubation: current controversy.

The changing opinion regarding some of the traditional components of rapid sequence induction and intubation (RSII) creates wide practice variations that impede attempts to establish a standard RSII protocol. There is controversy regarding the choice of induction drug, the dose, and the method of administration. Whereas some prefer the traditional rapid injection of a predetermined dose, others use the titration to loss of consciousness technique. The timing of neuromuscular blocking drug (NMBD) administration is different in both techniques. Whereas the NMBD should immediately follow the induction drug in the traditional technique, it is only given after establishing loss of consciousness in the titration technique. The optimal dose of succinylcholine is controversial with advocates and opponents for both higher and lower doses than the currently recommended 1.0 to 1.5 mg/kg dose. Defasciculation before succinylcholine was traditionally recommended in RSII but is currently controversial. Although the priming technique was advocated to accelerate onset of nondepolarizing NMBDs, its use has decreased because of potential complications and the introduction of rocuronium. Avoidance of manual ventilation before tracheal intubation was traditionally recommended to avoid gastric insufflation, but its use is currently acceptable and even recommended by some to avoid hypoxemia and to "test" the ability to mask ventilate. Cricoid pressure remains the most heated controversy; some believe in its effectiveness in preventing pulmonary aspiration, whereas others believe it should be abandoned because of the lack of scientific evidence of benefit and possible complications. There is still controversy regarding the best position and whether the head-up, head-down, or supine position is the safest during induction of anesthesia in full-stomach patients. These controversial components need to be discussed, studied, and resolved before establishing a standard RSII protocol.