Sepsis and septic shock are clinical emergencies requiring immediate treatment and fluid resuscitation. Early effective fluid resuscitation can improve the prognosis of patients. So far, there is no perfect crystalloid solution. Normal saline is the most readily available and economical crystalline fluid for clinical resuscitation. It is isoosmotic and can meet the basic needs of patients in the early rehydration. But it lacks acid-base buffer system and potassium, calcium and magnesium ions, and the level of chloride ions is also significantly higher than that of plasma.~Sodium Bicarbonate Ringer's solution contains physiological levels of Na+(130mmol/L), K+(4mmol/L), Ca2+(1.5mmol/L), Mg2+(1mmol/L), HCO3-(28mmol/L) and Cl-(109mmol/L). It also has citric acid/ sodium citrate buffer system (Citrate3-1.3mmol/L), pH7.3, and osmotic pressure 276mOsm/L. It is the most similar solution to extracellular fluid.~Theoretically，Compared with normal saline, Sodium Bicarbonate Ringer's solution can maintain acid-base balance faster and better when restoring the microcirculation without affecting the level of chloride ion. Therefore we hypothesize that Sodium Bicarbonate Ringer's solution can promote the body to restore to acid-base balance more quickly, and improve organ function more significantly than normal saline.
At present, people still have different opinions on choosing which kind of crystalloid solution for patients with sepsis, and there is no unified standard yet. It is necessary to conduct systematic studies on comparison of different fluid resuscitation methods on the efficacy and safety of crystalloid solution for patients with sepsis. Therefore, this study focuses on the efficacy and safety of sodium bicarbonate Ringer's solution compared with normal saline.