Pro: Hydroxyethyl Starch Is Preferable to Albumin in the Perioperative Management of Cardiac Patients

Recent progress in chemical modification of starch and its applications

Starch has received much attention as a promising natural material both in biomedical fields and waste water treatment due to its unique biological and adsorptive properties.

The efficacy and safety of colloid resuscitation in the critically ill

Despite evidence from clinical studies and meta-analyses that resuscitation with colloids or crystalloids is equally effective in critically ill patients, and despite reports from high-quality clinical trials and meta-analyses regarding nephrotoxic effects, increased risk of bleeding, and a trend toward higher mortality in these patients after the use of hydroxyethyl starch (HES) solutions, colloids remain popular and the use of HES solutions is increasing worldwide. We investigated the major rationales for colloid use, namely that colloids are more effective plasma expanders than crystalloids, that synthetic colloids are as safe as albumin, that HES solutions have the best risk/benefit profile among the synthetic colloids, and that the third-generation HES 130/0.4 has fewer adverse effects than older starches. Evidence from clinical studies shows that comparable resuscitation is achieved with considerably less crystalloid volumes than frequently suggested, namely, <2-fold the volume of colloids. Albumin is safe in intensive care unit patients except in patients with closed head injury. All synthetic colloids, namely, dextran, gelatin, and HES have dose-related side effects, which are coagulopathy, renal failure, and tissue storage. In patients with severe sepsis, higher doses of HES may be associated with excess mortality. The assumption that third-generation HES 130/0.4 has fewer adverse effects is yet unproven. Clinical trials on HES 130/0.4 have notable shortcomings. Mostly, they were not performed in intensive care unit or emergency department patients, had short observation periods of 24 to 48 hours, used cumulative doses below 1 daily dose limit (50 mL/kg), and used unsuitable control fluids such as other HES solutions or gelatins. In conclusion, the preferred use of colloidal solutions for resuscitation of patients with acute hypovolemia is based on rationales that are not supported by clinical evidence. Synthetic colloids are not superior in critically ill adults and children but must be considered harmful depending on the cumulative dose administered. Safe threshold doses need to be determined in studies in high-risk patients and observation periods of 90 days. Such studies on HES 130/0.4 are still lacking despite its widespread and increasing use. Because there are safer and equally effective alternatives in the form of crystalloids, use of synthetic colloids should be avoided except in the context of clinical studies.

Rationale for albumin infusions

PURPOSE OF REVIEW

To describe the metabolism and function of albumin, and to scrutinize the evidence that infusion of albumin may be beneficial in disease. To explain why albumin infusion does not improve clinical outcome in most disease states, studied.

RECENT FINDINGS

Albumin acts as a binding protein and an oncotic agent. However, albumin may also act as an extracellular scavenger, which leads to oxidation of albumin. It is likely that this compromises its function and it is possible that this drives its degradation. In disease, these useful processes are accelerated leading to rapid ageing of the molecule.Albumin infusion does not improve clinical outcome despite increasing oncotic pressure in chronic disease. It is not superior to nonprotein colloids or electrolyte solutions in acute hypovolemia with one or two exceptions (liver failure, possibly cerebral infarction). One potential explanation is that pharmaceutical albumin does not have the oxidative qualities that freshly synthesized albumin has.

SUMMARY

Albumin infusion has not proven to achieve clinical benefit in many acute and chronic disease states with a few exceptions in acute hypovolemia (e.g. postparacentesis). Future studies should reveal whether infusion of freshly synthesized nonoxidized albumin is of greater clinical benefit.