The American Heart Association recommends the use of intraosseous (IO) cannulation before resorting to endotracheal (ET) administration of cardiopulmonary resuscitation (CPR) medications. This is based on multiple studies in children and adults documenting safe and effective fluid resuscitation, drug delivery, and blood sampling with the IO approach. Furthermore, IO cannulation enables drug delivery comparable with that achieved by using a central line. This may be in part related to the noncollapsible venous plexus accessed in the IO approach. Any drug that can be given for resuscitation intravenously can also be given IO. In adults the sternum or proximal tibia has been successfully used for IO drug delivery. There are commercially available kits that facilitate IO access in adults.

If IV or IO access is not available, the ET route should be used. The medications that can be given ET include the NAVEL drugs: naloxone; atropine; vasopressin; epinephrine; and lidocaine (Table 43.1). Additionally, vasopressin may be administered via the ET route. Blood levels of drugs given the ET route are lower than comparable blood levels when drugs are given intravenously. The optimal dose of ET-administered medications is unknown, but generally should be given at least 2 to 2.5 times greater than the IV dose, with two studies suggesting the required dose of epinephrine given ET should be 3 to 10 times higher than the equipotent IV dose. The administered endotracheal medications should be given in 5 to 10 mL of water or normal saline and then flushed with several brisk ventilations with a bag-mask valve. Some published studies examining ET-administered
epinephrine and lidocaine showed that dilution with water, rather than normal saline, may achieve better absorption.