Fluids are probably the most commonly administered intravenous treatment in inpatient care. Because of their excellent safety profile, until recently fluid solutions were not considered "medications". Little to no thought was therefore invested in the choice of fluids to be administered in specific clinical scenarios. However, recent evidence on long-term effects has altered our view on the different types of fluids available for fluid resuscitation. Intravenous fluids should be seen as drugs affecting the cardiovascular, renal, gastrointestinal and immune systems and should therefore not be administered "blindly".
Emphasis on the importance of volume above all the other characteristics of the fluids administered was nurtured by early guidelines that focused on administering specific fluid volumes to hemodynamically unstable patients (i.e. the surviving sepsis campaign).[2,3] It is true that fluid administration is an important component of treatment of overt tissue hypoperfusion and hypoxia. Fluids may expand the intra-vascular compartment, thereby improving cardiac output (CO) and end-organ perfusion.[3,4] However, the most common error with regards to fluid administration is the belief that resuscitation hinges on transfusion of a specific volume of fluids.[3,5]
Disease processes are dynamic and their response to fluid may change over time. Specific disease states may also require different fluid therapy. Evidence from perioperative settings has associated both hypo- and hypervolemia with several unfavorable outcomes, including acute kidney injury (AKI), respiratory complications, increased lengths of stays, admission costs and 30-day-mortality rates.[6,7] Later iterations of the guidelines have therefore clarified that the aim of fluid resuscitation is restoration of end-organ perfusion and correction of physiological imbalance. Follow-up during fluid administration should therefore include surrogate markers of organ perfusion (e.g. mean arterial pressure, central venous oxygen saturation, lactate, CO), markers of circulation, blood electrolyte and acid-base composition and indicators of renal function.[3,8] No fluid is ideal for all disease conditions at all times. This review presents the current state of knowledge regarding the types of fluids to be administered with an emphasis on several disease states.
BMC Anesthesiol. 2018;18(200) © 2018 BioMed Central, Ltd.