Use of intraosseous blood to assess blood chemistries and hemoglobin during cardiopulmonary resuscitation with drug infusions

Objective: To compare intraosseous with central venous blood samples for biochemical analyses and hemoglobin levels during cardiopulmonary resuscitation (CPR) and during cardiopulmonary resuscitation with infusion of sodium bicarbonate, epinephrine, and saline boluses through the intraosseous site. Design: Prospective, complete repeated measures study. Setting: An animal laboratory at a university medical center. Subjects: Thirty-two piglets (mean weight, 30 [range, 24-35] kg). Interventions: Animals were anesthetized, instrumented, and subjected to hypoxic cardiac arrest. An intraosseous cannula was inserted into the tibia, and animals were randomly assigned to one of five groups: heparinized saline (n = 6), epinephrine infusions only (n = 6), saline infusions only (n = 6), sodium bicarbonate infusions only (n = 8), and epinephrine, saline, and sodium bicarbonate infusions through the same site (n = 6). CPR (chest compressions and mechanical ventilation) was performed in all groups. Simultaneous blood samples were taken from the central venous and intraosseous sites before arrest and after 5 and 30 mins of CPR. Measurements and Main Results: There were no differences (p < .05) in sodium, potassium, magnesium, lactate, and calcium values of intraosseous and central venous blood at the baseline and during 5 mins of CPR with infusions through the intraosseous cannula, At 30 mins, differences were apparent in magnesium, potassium, and sodium values between groups when the intraosseous cannula was used for infusions as well as sampling. Intraosseous potassium, glucose, and magnesium values were lower and sodium values were higher than central venous blood levels, No differences were seen at all sampling intervals if small-volume heparinized saline was given through the intraosseous site. Hemoglobin values were lower in the intraosseous group after 30 mins of CPR and infusions through the intraosseous site. After 30 mins of CPR, all hemoglobin values from the intraosseous site were <10 g/100 mt, Conclusion: Intraosseous and central venous blood biochemical and hemoglobin values were similar during hemodynamic stability and throughout 30 mins of resuscitation if no drugs were given through the intraosseous site. However, differences existed after 30 mins of CPR and infusions through the intraosseous site. Laboratory values may be erroneous when intraosseous blood is used during periods of resuscitation of >5 mins if drugs and fluid boluses have also been infused through the site. For reliable values, an intraosseous site for sampling only may be reasonable.