Renal

Question 1

RRT

Answer 1

CVVHF, CVVDF or CVVHDF

Filter - convection or solvent drag
Dialysis - diffusion

Prescription:
1 - Effulent rate/filtration rate - 25-30ml/kg/hr
2 - Blood flow rate - 250-300mls/min
3 - Fluid balance aim
4 - Anticoag - systemic: heparin, fondaparinux, LMWH - regional: heparin, citrate

Evidence:
AKIKI - no difference mort between early or late RRT
ELAIN - improvement with early RRT but single-centre and mainly post-surgical
IDEAL-ICU - septic shock, early vs late - no diff, stopped early

Question 2

Citrate Anticoag

Answer 2

Calcium chelator
Ionised calcium used to be called FIV
Stops II, VII, IX and X
Must reduced ionised calcium to 0.4 to work

Citrate metabolised in Krebs cycle - equivalent to leaving behind 3 HCO3 ions - can cause metabolic alkalosis

Extends life of filter
No systemic anticoagulation

Citrate toxicity - high/normal total Ca but low ionised calcium - causes a metabolic acidosis followed by a metabolic alkalosis