Effects of sodium bicarbonate on resuscitation in swine model of asphyxia cardiac arrest

Objective To study the effects of sodium bicarbonate (SB) on resuscitation in swine model of asphyxiation cardiac arrest (CA) . Methods Thirty-two healthy miniature pigs were randomized (ramdom number) into two groups, the SB group (n=16) and the control group (n=16) . Animals in both groups underwent endotracheal tube clamping to induce CA. Once induced, CA left untreated for a period of 8 minutes. At the beginning of initiation of cardiopulmonary resuscitation (CPR) , SB (1.0 mEq/kg, diluted to 40 mL) was injected in central venous in SB group and isopyknic normal saline solution was injected in control group. Two minutes following initiation of CPR, defibrillation was attempted until return of spontaneous circulation (ROSC) was achieved or animals died. To assess the SB effects on myocardial metabolism, positron emission tomography (PET) was performed at baseline and 6 after ROSC. To analyze18F-FDG myocardial uptake identified in PET, the maximum standardized uptake value (SUVmax) was measured. Results ROSC was 10/16 successful in SB group and only 8/16 successful in control group. The average survival time of SB group was (3.63±0.76) h and that of control group was (2.45±0.70) h. Myocardial metabolism imaging using PET demonstrated that myocardial metabolism injuries in control group were more severe than in SB group at 6 h after ROSC and SUVmax was more higher in SB group than in control group (6 hrs after ROSC: 1.32±0.20 vs. 1.10±0.14, P=0.035) . Conclusions In swine model of asphyxiation CA, SB improve the myocardial metabolism and might raise the possibility of ROSC and have no hypernatronemia. Key words: Asphyxia; Cardiac arrest; Sodium bicarbonate; Myocardial metabolism; Positron emission tomography; Hypernatronemia; Return of spontaneous circulation; Resuscitation