title: Acid-base status of blood from intraosseous and mixed venous sites during prolonged cardiopulmonary resuscitation and drug infusions.
abstract: OBJECTIVE
  a) To determine the relationship of acid-base balance (pH, PCO2) of blood samples from the intraosseous and the mixed venous route during prolonged cardiopulmonary resuscitation; b) to compare the effect of separate infusions of epinephrine, fluid boluses, or sodium bicarbonate through the intraosseous sites on the acid-base status of intraosseous and mixed venous blood during cardiopulmonary resuscitation; and c) to compare pH and Pco2 of intraosseous and mixed venous blood samples after sequential infusions of fluid, epinephrine, and sodium bicarbonate through a single intraosseous site.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Animal laboratory at a university center.
  
  
  METHODS
  Thirty-two mixed-breed piglets (mean weight, 30 kg).
  
  
  METHODS
  Piglets were anesthetized and prepared for blood sampling and cardiopulmonary resuscitation. After anoxic cardiac arrest, ventilation was resumed and chest compression was resumed. Blood gas samples from the pulmonary artery and both intraosseous sites were obtained simultaneously at baseline, at cardiac arrest, and at 5, 10, 15, 20, and 30 mins of cardiopulmonary resuscitation for group 1 (control group) and after drug (epinephrine and sodium bicarbonate) and saline infusions via one of the intraosseous cannulas in groups 2 through 5.
  
  
  RESULTS
  We found no differences between intraosseous and mixed venous pH and Pco2 during periods of <15 mins of cardiopulmonary resuscitation. However, this relationship was not maintained during prolonged cardiopulmonary resuscitation and after bicarbonate infusion. After large volume saline infusion, the pH and Pco2 of mixed venous and intraosseous blood were similar. During epinephrine infusion, the relationship between intraosseous and mixed venous pH and Pco2 was similar to that found in the control group.
  
  
  CONCLUSIONS
  The intraosseous blood sample could be used to assess central acid-base balance in the early stage of arrest and cardiopulmonary resuscitation of <15 mins. However, during cardiopulmonary resuscitation of longer duration, drug infusions may render the intraosseous site inappropriate for judging central acidosis.
authors.affiliation: Department of Pediatrics, University of Florida, USA.
authors.forename: T
authors.initials: T
authors.lastname: Abdelmoneim
authors.forename: N
authors.initials: N
authors.lastname: Kissoon
authors.forename: L
authors.initials: L
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Fiallos
authors.forename: S
authors.initials: S
authors.lastname: Murphy
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects; D000138:Acidosis / Q000503:physiopathology / Q000517:prevention & control*; D000322:Adrenergic Agonists / Q000627:therapeutic use; D000818:Animals; D001784:Blood Gas Analysis / Q000379:methods; D001800:Blood Specimen Collection / Q000379:methods*; D001842:Bone and Bones; D016887:Cardiopulmonary Resuscitation; D002648:Child; D004837:Epinephrine / Q000627:therapeutic use; D005440:Fluid Therapy; D006323:Heart Arrest / Q000188:drug therapy; D006801:Humans; D011446:Prospective Studies; D011897:Random Allocation; D017693:Sodium Bicarbonate / Q000627:therapeutic use; D013552:Swine; D013997:Time Factors; D014680:Veins
chemical_list: D000322:Adrenergic Agonists; D017693:Sodium Bicarbonate; D004837:Epinephrine