Table 3.

Monitoring of regional citrate anticoagulation for continuous RRT

Parameter	Monitoring Intervals	Aim
Circuit ionized calcium (postfilter)	Within 1 h from the start of the treatment and then at least every 6–8 h	To evaluate the maintenance of circuit ionized calcium within the intended target and modify citrate dose accordingly
Systemic ionized calcium	Baseline (before starting RRT)	To check baseline levels and set initial calcium infusion rate
	Within 1 h from the start of the treatment and then at least every 4–6 h	To evaluate the maintenance of systemic ionized calcium within the physiologic range and modulate calcium infusion rate accordingly
Systemic total calcium	At least every 12–24 h (simultaneous to systemic ionized calcium)	To calculate calcium ratio (total-to-ionized systemic calcium) as an indirect index of citrate accumulation (≥2.5)
Acid-base parameters (pH and bicarbonate)a	Baseline (before starting RRT)	To exclude acid-base imbalances (metabolic acidosis or alkalosis) and modify RCA and RRT parameters setting if needed
	Within 1 h from the start of the treatment and then at least every 4–6 h
Magnesium	At least every 24 h	To modulate the amount of magnesium supplementation if needed
Serum sodium	Once daily	To exclude hypernatremia or hyponatremia (rarely observed with a correct matching of RCA solutions)
Citratemia (if available)	Not routinely used for clinical purposes	To confirm hypercitratemia in the presence of indirect signs of citrate accumulation
Serum lactate	Baseline (before starting RRT)	To identify patients at higher risk for citrate accumulation and monitor lactate levels during RCA
	At least every 6–12 h or according to clinical needs

^aSample drawn from an arterial line.