Table 2

Metabolic derangements and adjustments during citrate anticoagulation

Derangement

Cause and signs

Adjustment

Metabolic acidosis

Insufficient removal of metabolic acids

Increase continuous renal replacement therapy dose

Anion gap increases

(filtrate or dialysate flow) to 35 ml/kg per hour

Loss of buffer substrate is higher than delivery

Increase bicarbonate replacement

or increase bicarbonate dialysate flow

or give additional bicarbonate

or increase citrate flow (cave accumulation)

Citrate metabolism decreases (iCa decreases, totCa/iCa increases [more than 2.1–2.5], and anion gap increases)

Decrease citrate delivery or stop

increase dialysate or filtrate flow

increase bicarbonate replacement

or increase bicarbonate dialysate flow

Metabolic alkalosis

Delivery of buffer substrate is higher than loss

Decrease bicarbonate replacement

or decrease bicarbonate dialysate flow

or stop additional bicarbonate i.v.

or decrease citrate flow (cave anticoagulation)

Decreased loss of buffer due to a decline in filtrate flow

Change filter

Increase filtrate flow

Hypocalcemia

Loss of calcium is higher than delivery (iCa decreases and totCa/iCa is normal)

Increase i.v. calcium dose

Citrate metabolism decreases (metabolic acidosis, totCa/iCa increases, and anion gap increases)

Increase i.v. calcium dose,

decrease or stop citrate delivery

increase dialysate or filtrate flow,

increase bicarbonate replacement

or increase bicarbonate dialysate flow

Hypercalcemia

Delivery of calcium is higher than loss

Decrease i.v. calcium dose

Hypernatremia

Delivery of sodium is higher than loss

Recalculate default settings

Protocol violation

• decrease sodium replacement

• decrease dialysate sodium content

• decrease trisodium citrate flow

Decreased loss of sodium due to a decline in filtrate flow

Change filter

Hyponatremia

Loss of sodium is higher than delivery

Recalculate default settings

Protocol violation

• increase sodium replacement

• increase dialysate sodium content

• increase trisodium citrate flow

iCa, ionized calcium; i.v., intravenous; totCa/iCa, ratio of total to ionized calcium.

Joannidis and Oudemans-van Straaten Critical Care 2007 11:218   doi:10.1186/cc5937