Recent studies have explored the traditional concept of the transfusion trigger. Hebert et al. (1999) demonstrated that the use of a threshold for red-cell transfusion as low as seven g/dL of hemoglobin combined with maintenance of hemoglobin concentrations in the range of seven to nine g/dL was at least as effective as, and possibly superior to, a liberal transfusion strategy (threshold, 10 g/dL; maintenance range, 10 to 12) in critically ill patients with normovolemia. This is with the possible exception of patients with acute myocardial infarction and unstable angina.

    The significant differences in mortality rates during hospitalization, rates of cardiac complications, and rates of organ dysfunction all favored the restrictive strategy. Findings also showed that maintaining hemoglobin concentrations within the seven to nine g/dL range decreased the average number of red-cell units transfused by 54 percent and exposure to any red cells after randomization by 33 percent.

    Higher transfusion triggers may lead to improved outcomes in certain populations. Wen-Chih et al. (2001) investigated 79,000 Medicare beneficiaries with acute myocardial infarction. It turned out that transfusion was effective in reducing the short-term mortality rate among elderly patients with anemia and acute MI. If the hematocrit upon admission was 30 percent or lower, transfusion may be effective in patients with hematocrit levels as high as 33 percent.

    Professor Jean-Francois Baron of Fresenius Kabi said that a hemoglobin trigger of seven to eight is the right trigger for most cardiac and critically ill patients. Patients with acute myocardial infarction or unstable angina should benefit from a transfusion trigger; and yet Baron also warned that these patients should not be overtransfused, "since we have seen when hemoglobin level is greater than 10, the effect of transfusion will be negative."

NORMOVOLEMIA AND VOLUME EXPANDERS

    According to Baron, there is a need to maintain normovolemia if the goal is to compensate for intraoperative or postoperative blood loss. So in order to "correctly maintain this normovolemia, we have to use artificial colloids," he said.

    Baron added that only two products can be compared--hydroxyethyl starch and gelatin. Although dextrans were used in the past, he noted, "they are not very much used today especially because of their side effects on coagulation, allergic reactions, and also some renal effects."

    Nonblood fluids known as volume expanders are administered to maintain blood volume. The term "volume therapy" covers everything from basic replenishment of water and electrolytes to the more complex task of restoring blood volume in cases of surgery, trauma, and shock. The use of an cases of surgery, trauma, and shock. The use of a product that is efficacious product with a high safety profile offers a number of benefits.

    In contrast to hydroxyethyl starch (HES), the main problem with gelatin, "is [its] origin." Transmissible spongiform encephalopathy (TSE) is the main concern, Baron said. This is why gelatin should be produced only from raw materials from countries where there is no TSE. The production process of gelatin should go through several steps that will destroy the agent responsible for the TSE transmission.

    Mortelmans (1995) compared the effects of six-percent HES and three-percent modified gelatin on intravascular volume and coagulation during intraoperative hemodilution. Results showed that gelatin is extravasated significantly more from the intravascular to the interstitial component.

    HAES-steril, the most efficacious and safest colloid on the market today was developed by Fresenius Kabi. To date, HAES-steril is accepted worldwide with over 50 million infusions and 500 publications proving it to be a superior colloid product. Miles Dumalagan