High chloride containing fluids are a problem

Quen MokGreat Ormond Street Hospital

Chloride: Queen of electrolytes?

Predominantly excreted by the kidneys99% reabsorbed

60% passively in proximal tubules following active sodium transport

15-25% in loop of Henle5% in distal tubule - aldosterone

Renal handling of Chloride

Renal excretion of Chloride

Hyperchloremic acidosisSo why is hyperchloremia a problem?

Immune activation and pro-inflammatoryRenal dysfunction – renal vasoconstriction and

decreased GFRClotting abnormalitiesIncreased mortality

Hyperchloremic acidosis

Infusions of 0.9% Saline and Plasmalyte on renal blood flow velocity and renal cortical tissue perfusionChowdhury AH et al Ann Surg 2012;256:18-24

Chloride rich solutionsSerum chloride 97-110 mmol/l0.9% saline – 154 mmol/l chloride4.5% Albumin – up to 160 mmol/l chloride

Hence large volumes potentiate metabolic acidosis regardless of the underlying disease process

Often unrecognised and poorly managedMisdiagnosed as inadequate perfusionBase deficit used as a key prognostic variable in

paediatric mortality risk score

Stewart approachPlasma pH determined by

Strong ion difference (SID) – difference between strong cations (Na, K, Ca, Mg) and strong anions (Cl and lactate)

PaCO2Weak acids (Atot) – mainly albumin and inorganic

phosphateDecreased SID has acidifying effect as changes

degree of water dissociation into hydrogen ions

Strong ion difference

Electrolyte composition of common IV fluids

Cations Anions Osm

Na K Ca Mg Cl Acetate Lactate Gluconate mosmol/l

Plasma 135-145 3.5-5.0 4.4-5.2 1.6-2.4 98-106 Bicarbonate 21-30 280-300

NaCl 154 0 154

Ringer lactate

130 4.0 3.0 109 28 273

Ringer acetate

130 4.0 4.0 2.0 110 30 277

Hartmann’s

131 5.0 4.0 111 29 278

Plasma-lyte

140 5.0 0 3.0 98 27 23 295

Dialysis Replacement solutionsAll contain high chloride levels (108-125 mmol/l)Lower if potassium free bicarbonate solutionsSerum electrolytes equilibrate with replacement fluid

Chloride is a major strong anion in the extracellular fluid space

Hyperchloremic acidosis causes renal vasoconstriction and decreased GFR

May be misinterpreted as inadequate tissue perfusion

Consider use of balanced solutionsSerum electrolyte equilibrate with dialysis

replacement fluid

Conclusions

Not the case with chloride…….