BACKGROUND: The objective of this systematic review and meta-analysis was to assess the relationship between the chloride content ofintravenous resuscitation fluids and patient outcomes in the perioperative or intensive care setting.CONCLUSION: A weak but significant association between higher chloride content fluids and unfavourable outcomes was found, but mortality was unaffected by chloride content.
The administration of intravenous fluid to critically ill patients is one of the most common but also one of the most fiercely debated interventions in intensive care medicine. During the past decade, a number of important studies have been published which provide clinicians with improved knowledge regarding the timing, the type and the amount of fluid they should give to their critically ill patients. However, despite the fact that many thousands of patients have been enrolled in these trials of alternative fluid strategies, consensus remains elusive and practice is widely variable. Early adequate resuscitation of patients in shock followed by a restrictive strategy may be associated with better outcomes. Colloids such as modern hydroxyethyl starch are more effective than crystalloids in early resuscitation of patients in shock, and are safe when administered during surgery. However, these colloids may not be beneficial later in the course of intensive care treatment and should best be avoided in intensive carepatients who have a high risk of developing acute kidney injury. Albumin has no clear benefit over saline and is associated with increased mortality in neurotrauma patients. Balanced fluids reduce the risk of hyperchloraemic acidosis and possibly kidney injury. The use of hypertonic fluids in patientswith sepsis and acute lung injury warrants further investigation and should be considered experimental at this stage. Fluid therapy impacts relevant patient-related outcomes. Clinicians should adopt an individualized strategy based on the clinical scenario and best available evidence. One size does not fit all.
Methods for the restoration of circulating blood volume, including the use of intravenous fluids, have been widely discussed over many years. There are no clear guidelines regarding the type of solutions, the total volume that should be transfused, or time schedules. Colloid solutions, usually hydroxyethyl starch compositions, are probably the most commonly used volume expanders in resuscitation, despite the lack of convincing trials and possible nephrotoxicity.In 2012, a task force of ESICM published a consensus statement on colloid use in critically ill adult patients. They stressed that infusion of an inappropriate volume may worsen the outcome of critically ill patients. Static parameters of cardiac filling volume, such as CVP or PCWP, commonly used in clinical practice, were found to be useless in the prediction of fluid responsiveness; volumetric or dynamic parameters, like global end diastolic volume (GEDV) or stroke volume variations (SVV), obtained by PICCO meters, seemed be much more appropriate. The dynamic fluid challenge test, which is transfusion of approx. 200 cc (or 3 mL kg-1) of any fluid over 5-10 min resulting in an increase of stroke volume, has also been recommended for the identification of those patients who may benefit from fluid resuscitation. The old passive leg raising test can also be used for this purpose.Despite prolonged discussion about fluid therapy in specific groups of critically ill patients, there is no convincing data to indicate the superiority of colloids over crystalloids. The choice of fluids is usually based on personal preference and hospital policy. Among crystalloid solutions, balanced preparations such as acetates, lactates, malates or citrates are recommended to avoid hyperchloraemia, a common side effect of saline infusion. There is no agreement regarding colloid solutions.The fluid transfusion regimen in criticallyill patients should therefore be based on clinical assessment and patient responses.