Lactate versus acetate buffered intravenous crystalloid solutions: a scoping review

Background: Buffered crystalloid solutions are increasingly recommended as first-line intravenous resuscitation fluids. However, guidelines do not distinguish between the different types of buffered solutions. The aim of this scoping review was to assess the evidence on the use of lactate-vs acetate-buffered crystalloid solutions and their potential benefits and harms. Methods: We conducted this scoping review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. We searched PubMed, Embase, Epistemonikos, and the Cochrane Library for studies assessing the effect of lactate-vs acetate-buffered crystalloid solutions on any outcome in adult hospitalised patients. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. Results: We included a total of 29 studies, 25 of which were clinical trials and four were observational studies. Most studies were conducted in surgical settings and indications for use were poorly described. The most commonly administered solutions were Ringer's lactate vs Ringer's acetate or Plasma-LyteT. Outcomes included acid/base and electrolyte status; haemodynamic variables; and markers of renal and liver function, metabolism, and coagulation. Only a few studies reported patient-centred outcomes. Overall, the data provided no firm evidence for benefit or harm of either solution, and the quantity and quality of evidence were low. Conclusions: The quantity and quality of evidence on the use of different buffered crystalloid intravenous solutions were low, data were derived primarily from surgical settings, and patient-important outcomes were rarely reported; thus, the balance between benefits and harms between these solutions is largely unknown.