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…….