title: Effects of intraosseous epinephrine in a cardiac arrest swine model.
abstract: BACKGROUND
  Interruptions in cardiopulmonary resuscitation (CPR) to obtain vascular access reduces blood flow to vital organs. Tibial intraosseous (TIO) access may be a faster alternative to intravenous (IV) access for delivery of vasoactive medications. The purpose of this study was to examine the differences in pharmacokinetics and pharmacodynamics of TIO- and IV-delivered epinephrine.
  
  
  METHODS
  A prospective, between subjects, experimental design comparing Cmax, Tmax, return of spontaneous circulation (ROSC), and time to ROSC. Adult male swine were divided into three equal groups (n = 7) all received CPR and defibrillation: the second group received IV epinephrine and the third group received tibial intraosseous epinephrine. Swine were placed in cardiac arrest for 2 min before CPR was initiated. After 2 min of CPR, epinephrine was delivered by IV or TIO, and serial blood samples were collected over 4 min.
  
  
  RESULTS
  There were no significant differences between IV versus TIO epinephrine in achieving ROSC, time to ROSC, and Cmax. A one-way analysis of variance demonstrated a significant difference between the IV and TIO groups in Tmax (P = 0.025). A Fisher exact test demonstrated a significant difference between IV epinephrine versus CPR/Defib only (P = 0.035) and TIO epinephrine versus CPR/Defib only (P = 0.010) in achieving ROSC. A multivariate analysis of variance showed significant differences in IV versus intraosseous epinephrine concentration at specific time intervals: 60 (P = 0.023), 90 (P = 0.001), and 120 (P < 0.000) sec.
  
  
  CONCLUSIONS
  In the context of ROSC, epinephrine delivered via TIO route is a clinically relevant alternative to IV administration. When IV access cannot be immediately obtained in cardiac arrest patients, TIO access should be considered.
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Wong
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas.
authors.forename: Matt J
authors.initials: MJ
authors.lastname: Reggio
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas.
authors.forename: Freddy R
authors.initials: FR
authors.lastname: Morocho
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Holloway
authors.affiliation: Department of Internal Medicine, Texas Tech University Health Science Center at El Paso, El Paso, Texas.
authors.forename: Jose C
authors.initials: JC
authors.lastname: Garcia-Blanco
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas.
authors.forename: Constance
authors.initials: C
authors.lastname: Jenkins
authors.affiliation: US Army Medical Department Center and School, Health Readiness Center of Excellence, Graduate school-US Army Graduate Program in Nursing Anesthesia, JBSA-FSH, San Antonio, Texas. Electronic address: arthurjohnso@gmail.com.
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Johnson
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004837:Epinephrine / Q000008:administration & dosage*; D006323:Heart Arrest / Q000188:drug therapy*; D017148:Infusions, Intraosseous; D008297:Male; D011897:Random Allocation; D013552:Swine; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*
chemical_list: D014662:Vasoconstrictor Agents; D004837:Epinephrine
keywords: Cardiopulmonary resuscitation; Epinephrine; Intraosseous; Intravenous; Pharmacokinetics; Return of spontaneous circulation