Acidosis is a marker of inadequate tissue perfusion and/or ventilation. It may also have detrimental effects on cardiovascular function. Failure of achieving a rapid central vascular access in a pulseless child precludes monitoring and therapy of acidosis. Objective: To determine the usefulness of intraosseous (IO) blood gases for judging central acidosis during prolonged CPR and after drug infusions. Methods: Thirty-two piglets were subjected to cardiac arrest followed by mechanical CPR. The animals were divided to 5 subgroups: CPR only (P-I), CPR/epinephrine (P-II). CPR/saline (P-III). CPR/bicarbonate (P-IV) and CPR/sequential infusions (P-V). Blood gases were drawn from tibial IO and internal jugular central venous (CV) sites simultaneously at steady state (Txx), arrest (T00) and T05, T10, T15, T20 and T30 min. of CPR infusions. Mean values of CV and IO blood pH and pCO2 were analyzed using paired difference t-test with p <.007 considered statistically significant. * Results: Table below summarizes the results at times specified. IO and CV mean pH values±.05 or mean pCO2 value ± 5 torr considered similar (Yes). NO, indicates non-similar values. Conclusion: Intraosseous blood may be useful in judging pH and pCO2 of the central circulation during short periods of CPR and after saline infusion. Prolonged CPR and infusion of epinephrine and sodium bicarbonate may render intraosseous sites useless for judging central acidosis.

Table 1
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