Pharmacokinetics of sternal intraossesous atropine administration in normovolemic and hypovolemic swine

Objective: Characterize and compare the pharmacokinetics of atropine administered via the sternal intraosseous (IO) route in a normovolemic and hypovolemic swine model.Design: Prospective, experimental study. Setting: Vivarium.Subjects: Yorkshire-cross swine (N = 12).Intervention: Atropine was administered via the sternal IO route to normovolemic and hypovolemic swine. Blood samples were drawn at regular intervals after atropine administration and analyzed for plasma atropine concentration. Pharmacokinetic parameters were obtained from modeling the plasma concentrations.Main Outcome Measurements: Pharmacokinetic parameters, maximum concentration (Cmax), and time to maximum concentration (Tmax).Results: The normovolemic and hypovolemic models reached peak plasma concentration immediately and had a very rapid distribution phase with no apparent absorption phase for the IO groups. The hypovolemic group had slower clearance and longer half-life compared to the normovolemic group.Conclusion: The sternal IO route is an effective method of administering atropine and is comparable to the previously reported tibial IO and intravenous data even under conditions of significant hemorrhage.