Effect of potassium chloride on rat ventricular fibrillation model during cardiopulmonary resuscitation / 中华危重病急救医学

ABSTRACT

Objective To investigate whether increasing the concentration of serum potassium facilitates the cardioversion to sinus rhythm during cardiopulmonary resuscitation (CPR) in a rat ventricular fibrillation (VF) model. Methods Sprague-Dawley (SD) rats with sustained VF by electrical induction were randomized into two groups by random number table. Five minutes after onset of electrical induction, 2.5% potassium chloride solution at a dose of 0.8 mL/kg (KCl group, n = 9) or equivalent normal saline (NS group, n = 9) was given respectively via femoral vein followed by traditional CPR. The changes of electrocardiogram (ECG) and the effect of defibrillation were compared between the two groups. Results During the CPR, the number of animals with spontaneous cardioversion (2 vs. 1, P = 1.000) and successful defibrillation (7 vs. 3, P = 0.026) were both increasing in KCl group compare with those in the NS group, which required fewer defibrillation (1.60±0.79 vs. 2.70±0.58, P = 0.064), lower calculative defibrillation energy (J 4.00±3.00 vs. 8.30±2.89, P = 0.068), more animals restore spontaneous circulation (ROSC, 9 vs. 4, P = 0.029) and shorter ROSC time (s 265.10±134.58 vs. 421.30±162.06, P = 0.096). At the beginning of CPR, animals in two groups all presented the fine amplitude (amplitude < 0.5 mV). At CPR 3 minutes the KCl group presented significantly larger amplitude compared with NS group (mV 0.92±0.16 vs. 0.67±0.23, P = 0.030); The amplitude decreased in the animals which did not attain cardioversion to sinus rhythm over time. The animal number of fine amplitude at CPR 7 minutes were 0 and 5, respectively, in the KCl group and the NS group. Conclusion Increasing serum potassium concentration facilitates the VF amplitude enlargement, promotes the spontaneous conversion, increases the successful rate of defibrillation and reduces the energy for defibrillation in a rat VF model.