title: What is the ideal crystalloid?
abstract: OBJECTIVE
  We discuss the importance of the composition of intravenous crystalloid solutions. On the basis of current physiologic principles, evidence from basic science and clinical experiments, recent observational studies, and clinical trials, we conclude that the 'ideal crystalloid' depends on clinical context. We make recommendations on solutions that may be used during critical illness, major surgery, and certain clinical situations.
  
  
  RESULTS
  The routine use of solutions with a supraphysiologic chloride content and a low strong ion difference (SID), such as isotonic saline solution, may be associated with adverse outcomes, especially among critically ill patients. On the contrary, solutions with a physiologic chloride content and a 'balanced' electrolyte composition (SID closer to plasma) may improve the likelihood of survival. The distribution of different types of crystalloids across traditional 'body compartments' is a function of osmolality of the fluid infused relative to plasma, integrity of the glycocalyx, and the hemodynamic/'volume' state of the patient. During critical illness, the routine administration of colloids may offer no clinical benefits compared with the use of crystalloids.
  
  
  CONCLUSIONS
  Crystalloids, like other types of intravenous fluids, are drugs with important effects on clinical outcomes that may be mediated by osmolality, chloride content, and SID.
authors.affiliation: aDivision of Veterans Affairs bDepartment of Anesthesiology, Duke University Medical Center/Durham VAMC, DUMC, Durham, North Carolina, USA.
authors.forename: Karthik
authors.initials: K
authors.lastname: Raghunathan
authors.forename: Patrick
authors.initials: P
authors.lastname: Nailer
authors.forename: Ryan
authors.initials: R
authors.lastname: Konoske
mesh_terms: D000418:Albumins / Q000627:therapeutic use*; D003422:Critical Care; D016638:Critical Illness / Q000401:mortality / Q000628:therapy*; D000077324:Crystalloid Solutions; D005440:Fluid Therapy; D006801:Humans; D007552:Isotonic Solutions / Q000627:therapeutic use*; D009994:Osmolar Concentration; D010952:Plasma Substitutes / Q000627:therapeutic use; D012151:Resuscitation
chemical_list: D000418:Albumins; D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes