Crystalloid fluid therapy: a review

Dr Santosh Kumar BhaskarCrystalloid fluid therapy: a recent review

Why 0.9%Saline is not normal ?It has high chloride contentStrong ion difference is 0.

The SID of the extracellular fluid is approximately 40mEq/l, whereas the SID of 0.9% saline is zero. Following an infusion of 0.9% saline there is a net decrease in the plasma SID resulting in a metabolic acidosis.

What about osmolality of 0.9%NaClTheoretical in vitro osmolality of 308mosmol/kg H2O (154mmol/l sodium plus 154mmol/l chloride).

However, 0.9% saline is more accurately referred to as an isotonic solution as its constituents sodium and chloride are only partially active, with an osmotic coefficient of 0.926. The calculated in vivo osmolality (tonicity) of saline is 285 mosmol/kgH2O

Buffered/balanced crystalloidsRINGERS SOLUTION HARTMANN SOLUTION

One of the key differences between 0.9% saline and buffered/balanced crystalloids is the presence of additional anions, such as lactate, acetate, malate and gluconate, which act as physiological buffers to generate bicarbonateSID of Ringer =SID of Hartmann=

Significance of buffering agentAcetateLactategluconate

Conditions and fluid of choicePerioperative periodRenal insufficiencyHemorrhagic shock

What about normal salineEx vivo testing of diluted whole blood reported that dilution with Ringers lactate resulted in less impairment in thrombin generation and platelet activation when compared to 0.9% saline .

A swine study reported that metabolic acidosis significantly impaired gastropyloric motility by reducing pyloric contraction amplitude, which results in delayed gastric emptying or gastroparesis .

Animal studies Rat sepsis modelBalanced salt solution is better than 0.9% NaCl.

Swine hemorrhagic shock modelRL is better than all others

Observational studies -1About 1500 patients of critical care and post surgeryComparison between chloride liberal and restrictive fluids.Result :Chloride restrictive have less AKI and RRT.NO change in mortality and ICU days

Yunos NM, Bellomo R, Hegarty C, Story D, Ho L, Bailey M. Association between a chloride-liberal vs chloride-restrictive intravenous fluid administration strategy and kidney injury in critically ill adults. JAMA. 2012;308:156672.

Observational studies -2Retrospective ,propensity matched study on septic shock patients who received fluid ,vasopressor and antibiotics on day 2 of ICU admission.In total 53,448 patients were identified from 360 hospitals over five years.3365 patients were compared for balanced and unbalanced fluidResult:Lower mortality in balance fluid group

Raghunathan K, Shaw A, Nathanson B, et al. Association between the choice of IV crystalloid and in-hospital mortality among critically ill adults with sepsis. Crit Care Med. 2014;42:158591.

Observational studies -3Retrospective ,propensity matched study on abdominal surgery patients group.In total 271,189 patients from approximately 600 hospitals had received fluids on the day of surgery. Of these patients, 30,994 received 0.9% saline and 926 received balanced fluid.Perioperative fluid either balanced or unbalanced fluid.Result :Balanced fluid group has less major complication than unbalanced group.

Shaw AD, Bagshaw SM, Goldstein SL, et al. Major complications, mortality, and resource utilization after open abdominal surgery: 0.9% saline compared to Plasma-Lyte. Ann Surg. 2012;255:8219.

Interventional studiesUntil 2015, all interventional studies comparing 0.9% saline to buffered crystalloid had a small sample size (n