Intravascular volume replacement therapy with synthetic colloids: is there an influence on renal function? Boldt J, Priebe HJ. Anesth Analg Feb;96(2): Ri /VS

Intravascular volume replacement Crystalloids versus colloids Synthetic colloids: – renal insufficiency – coagulopathy

Development of Renal failure-I Preexisting kidney and vascular disease Medication (ACEI, Abx, catecholamines, volatile anesthetics, etc.) DM Unstable hemodynamics Hypothermia Hypoxia Cardiopulmonary bypass The elder

Development of Renal failure-II Decline in GFR Need for hemofiltration of hemodialysis Twofold incease in Scr Prerenal azotemia ICU and post-op patient

Hyper-oncotic ARF All colloids may induce ARF by increasing the plasma colloid osmotic pressure Dehydrated patient + considerable amounts of hyperoncotic colloids without additional crystalloids P eff = (P cap – P bow )- P pla

Gelatins and Dextran Gelatin – Appear to be without adverse effects on kidney function – Lack of data DEX – Low molecular weight DEX – Multi-factorial, including hyper-oncotic ARF, tubular obstruction, and direct toxicity – Renal biopsies: osmotic nephrosis (unspecific)

Hydroxyethyl starch (HES) Amylopectin hydrolysis and hydroxyethylation high polymeric glucose compound Physicochemical character: – Molecular weight (different elimination pathway) – Concentration – Degree of substitution – C2/C6 hydroxyethylation ratio

Characteristics of the Different Colloids

Hydroxyethyl starch (HES) Reabsorption of macromoleules – Swelling of tubular cells tubular obstruction and medullary ischemia Hyperviscous urine and a stasis of tubular flow – Obstruction of the tubular lumen Increase in plasma oncotic pressure

Hydroxyethyl starch (HES) The precise mechanism ? Is the amount of administered HE of importance ? Relation between osmotic nephrosis-like lesions and kidney function ? Unknown !

Non-surgical, non -ICU

The slow degradable HES preparation was an independent risk factor for the development of ARF. Long-term(>5 days) admin. +elderly (MAP>65mmHg)

Study Limitations End points of intravascular volume therapy are often not exactly defined (to maintain stable hemo- dynamics?) Renal function was assessed by rather in- sensitive variables Investigation of effect on variables of renal function, rather than on outcome

Study Limitations Differences in physicochemical properties between synthetic colloids ( low DS appear to have less risk than high DS) Lack of control group Different kinds of patients (underlying disease)

Conclusions HES can be used safely even in large doses in patients without altered kidney function – In patients with increased serum creatinine concentrations (>2-3 mg/dL), HES should be used cautiously – There is no study that defines a critical serum creatinine concentration that would contraindicate the use of HES – Other colloid regimens (gelatin or albumin) or crystalloids should be used hyperoncotic ARF Vogt NH, Bothner U, Lerch G, et al. Large-dose administration of 6% hydroxyethyl starch 200/0.5 for total hip arthroplasty: plasma homeostasis, hemostasis, and renal function compared to use of 5% human albumin. Anesth Analg 1996;83:262–8.

Conclusions Rapidly degradable HES preparation usage in patients with moderate to severe kidney dysfunction showed no deterioration in kidney function Jungheinrich C, Scharf R, Wargenau M, et al. The pharmacokinetics and tolerability of an intravenous infusion of the new hydroxyethylstarch 130/0.4 (6%, 500 mL) in mild-to-severe renal impairment. Anesth Analg 2002;95:544– 51.

Thanks for Your Attention ! Nephrol Dial Transplant Sep;20(9): Albumin and hydroxyethyl starch 130 kDa/0.4 improve filter clearance and haemocompatibility in haemo- and plasmafiltration--an in vitro study. Unger JK, Haltern C, Dohmen B, Gressner A, Grosse- Siestrup C, Groneberg DA, Rossaint R. Unger JKHaltern CDohmen BGressner AGrosse- Siestrup CGroneberg DARossaint R