AN ALTERNATIVE SODIUM-BICARBONATE REGIMEN DURING CARDIAC-ARREST AND CARDIOPULMONARY-RESUSCITATION IN A CANINE MODEL

We evaluated the effect of frequent, early bolus administration of low -dose sodium bicarbonate (NaHCO3) on blood gas values during ventricul ar fibrillation and cardiopulmonary resuscitation (CPR) compared with normal saline and standard bolus doses of NaHCO3, This was a randomize d laboratory investigation involving 13 mongrel dogs and 18 experiment s (5 dogs were used in a crossover manner). Each dog underwent 3 minut es of ventricular; fibrillation, followed by 15 minutes of CPR. Animal s were randomly assigned to one of three treatments administered early in the resuscitation effort: NaHCO3 0.5 mEq/kg at 5, 10, and 15 minut es of ventricular fibrillation (SB); NaHCO3 1; mEq/kg at 5 minutes and 0.5 mEq/kg at 15 minutes of fibrillation (B); or 0.9% NaCl 1 ml/kg at 5 minutes and 0.5 ml/kg at 15 minutes of fibrillation (P). A total of 15 experiments were included for analysis. Arterial and venous blood gases were sampled at 4, 8, 13, and 18 minutes of fibrillation. The SB group demonstrated the highest arterial partial pressures of carbon d ioxide (pCO(2)) at each sampling point after NaHCO3, including the 18- minute sample: 42+/-12, 29+/-11, and 35+/-10 torr for SB, P, and B, re spectively. In addition, SB produced arterial alkalemia (pH>7.45) afte r NaHCO3 administration. The arterial pH at 18 minutes of fibrillation for SB, P, and B was 7.46+/-0.14, 7.29+/-0.07, and 7.41+/-0.1, respec tively. Similar trends for pCO(2) and pH were observed for venous samp les. Early, frequent administration of;low-dose NaHCO3 during CPR is a ssociated with elevated pCO(2) and pH (alkalotic) values that may be p otentially detrimental in this setting. It appears that this mode of a dministration offers no advantage over B with regard to blood gas valu es during CPR in this canine model.