Influence of an acetate- and a lactate-based balanced infusion solution on acid base physiology and hemodynamics: an observational pilot study

Twenty-four women who had undergone abdominal gynecologic surgery and who had received either Ringer’s lactate (Strong Ion Difference 28 mmol/L; n？=？12) or an acetate-based solution (Strong Ion Difference 36.8 mmol/L; n？=？12) according to an established clinical protocol and its precursor were included in the investigation. After induction of general anesthesia, a set of acid–base variables, hemodynamic values and serum electrolytes was measured three times during the next 120 minutes.Patients received a mean dose of 4,054？±？450 ml of either one or the other of the solutions. In terms of mean arterial blood pressure and norepinephrine requirements there were no differences to observe between the study groups. pH and serum HCO3- concentration decreased slightly but significantly only with Ringer’s lactate. In addition, the acetate-based solution kept the plasma effective strong ion difference more stable than Ringer’s lactate.Both of the solutions provided hemodynamic stability. Concerning consistency of acid base parameters none of the solutions seemed to be inferior, either. Whether the slight advantages observed for the acetate-buffered solution in terms of stability of pH and plasma HCO3- are clinically relevant, needs to be investigated in a larger randomized controlled trial.In the fields of surgery and intensive care, hyperchloremic acidosis is a well-known problem in patients receiving large amounts of standard crystalloids, especially 0.9% sodium chloride solutions. A series of investigations has emphasized the disadvantageous effects of hyperchloremic acidosis on various organ systems, for example, hemodynamics, NO-production, renal blood circulation, urinary output or hemostasis [1-4]. Balanced crystalloids, whose composition prevents hyperchloremia, are increasingly accepted and likely to be ‘state of the art’ in the near future [3,5-7]. Balanced hydroxyethyl-starch solutions are also available today. All of these preparations are characterized by the pre