Effects of 6% hydroxyethyl starch and 3% modified fluid gelatin on intravascular volume and coagulation during intraoperative hemodilution.

In the perioperative period, artificial colloids are most often infused in doses of 500-1000 mL intravenously. This randomized study compared the effects on intravascular volume and coagulation of approximately 2000 mL of two isooncotic artificial colloids: 6% hydroxyethyl starch (HES; MW 200,000; substitution ratio 0.40-0.55) and 3% modified fluid gelatin (GEL). We hypothesized more pronounced hypocoagulation with HES and a weaker intravascular volume effect of GEL. Forty-two patients, scheduled for primary total hip replacement, were allocated randomly to receive HES or GEL during acute normovolemic hemodilution and subsequent further intraoperative hemodilution. Blood samples were taken before and after 500 mL and 1000 mL of acute normovolemic hemodilution; intraoperatively after 20 mL/kg of artificial colloid and at the end of colloid infusion; on arrival in the recovery room; and 3 h later. We quantified: 1) coagulation variables; 2) blood loss; 3) hemodynamic stability; 4) necessary infusion volume; 5) interstitial extravasation, calculated from plasma volunteers measured using albumin marked with technetium-99m and iodine-125, respectively; 6) percentage volume effect at the end of the study as well as hematocrit, total serum protein, and colloid osmotic pressure. Intraoperative volume therapy was guided by radial systolic pressure and systolic pressure variation, mixed venous hemoglobin saturation in the pulmonary artery, and pulmonary capillary occlusion pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of an equal volume replacement with 500 mL 6% hydroxyethyl starch on the blood and plasma volume of healthy volunteers.

The effect of an equal volume replacement with 6% low molecular weight (200,000) hydroxyethyl starch (substitution ratio 0.60-0.66) (Elohaes) on the blood volume and plasma volume of eight healthy volunteers was investigated with special attention to volume overshooting. After replacement of 500 mL whole blood, blood volume was measured repeatedly for 8 1/2 h using chromium-51 labelled erythrocytes. Red cell volume and plasma volume were calculated from standard formulae. After replacement, blood and plasma volumes were unchanged from control (4754 +/- 630 mL and 2900 +/- 450 mL, respectively). The haematocrit decreased from 43.7 +/- 2.5% to 39.0 +/- 1.4% (1 h after starch infusion) and 41.1 +/- 1.9% (7.5 h after starch infusion). There were no significant changes in haemodynamic variables (systolic and diastolic blood pressure; heart rate), liver function (bilirubin; transaminases), renal function (serum creatinine; serum sodium) or coagulation (activated partial thromboplastin time). Alpha-amylase was significantly increased, which is a well known effect of starches. The replacement of 500 mL whole blood by hydroxyethyl starch maintains isovolaemia for at least 8 h in normal volunteers without any significant volume overshooting; this is not what was seen in earlier studies. This should increase safety in patients with cardiac disease.

Quality of washed salvaged red blood cells during total hip replacement: a comparison between the use of heparin and citrate as anticoagulants.

A randomized, prospective study comparing heparin with citrate (ACD) as anticoagulant during red blood cell saving was performed in 10 ASA grade I-II patients undergoing primary total hip replacement. Blood samples were taken before and after surgery and at several steps during cell saving. In the heparin group, salvaged red cells showed normal values, with the exception of decreased filtrability and moderate hemolysis. More differences in red cell quality were found in the ACD group. Mean corpuscular volume was higher (110 vs 95 x 10(-12) mL), red cell distribution was increased (17% vs 13%), osmotic resistance was lower (0.54 vs 0.43 g NaCl/L at 50% hemolysis), antioxidative reserve capacity was lower (1.9 vs 4.6 U glutathione reductase per gram of hemoglobin) and there was more hemolysis (15% vs 11%). Despite the small volume of autologous blood retransfused (388 +/- 92 mL), the differences in vitro produced significantly higher free hemoglobin levels in the patients' plasma at the end of the operation (58 vs 23 mg/dL). We conclude that heparin is preferable to citrate as an anticoagulant during autotransfusion with cell washing and immediate retransfusion.

A simple method for calculating component dilution during fluid resuscitation: the Leuven approach.

STUDY OBJECTIVES: To test the reliability of the Leuven approach, a balance between oversimplified empiric rules and more complex calculations requiring the use of nomograms or computers, to determine blood component dilution during large transfusions. To present schemes for blood component dilution and stabilization, as well as four examples showing the practicability of the method. DESIGN: Prospective study. SETTING: Orthopedic operating rooms at a university hospital. PATIENTS: 108 patients undergoing total hip replacement with expected large blood loss. INTERVENTIONS: Component concentrations were measured after patient arrival in the recovery room. Blood loss was followed clinically. MEASUREMENTS AND MAIN RESULTS: Preset target component concentrations [hematocrit (Hct) 31%; total serum protein (TSP) 5.0 g/dl; prothrombin time (PT) 50%; blood platelets (BLPL) 50,000/microliters)] were compared with concentrations measured on arrival in recovery after dilution and stabilization, according to the transfusion scheme. Average blood loss was 3,226 +/- 1,600 ml (mean +/- SD). End component concentrations were Hct, 33.4% +/- 3.3%; TSP, 5.2 +/- 0.5 g/dl; PT, 52% +/- 12%; BLPL, 97,000/microliters. Hct and TSP showed significant (p < 0.05) but clinically unimportant differences from target concentrations. Possible reasons for variability in end concentrations are discussed. CONCLUSION: The Leuven approach produces reliable blood component concentrations after extensive transfusions. It allows the clinician to decide for himself or herself, in accordance with general consensus and the patient's individual needs, when to stabilize blood components.

A balanced view on intra- and postoperative blood salvage.

Increasing fear of transfusion related HIV infection, due to recent problems in West European countries, could result in an exaggerated confidence in autologous transfusion techniques. The author, being an anesthesiologist working in a blood bank since one year, tries to put forward a balanced opinion. After a short historical overview, the three main groups of blood salvage techniques are presented: intraoperative blood salvage without and with cell washing as well as postoperative salvage. For each group the following items are discussed: careful technique, quality of the autologous blood, indications, side effects, limitations, efficiency and cost. It is demonstrated that blood salvaging is not the first choice in a global blood sparing and safety program. Some sort of routine quality control should be instituted and if necessary (the safest possible) homologous blood should be preferred. Finally, a practical proposal for elective surgery is roughly made, stressing the life saving potential of blood salvaging in emergency situations.

Protocol and preliminary results of a clinical study for comparison of solvent/detergent-inactivated plasma VIP versus FFP with special consideration of the balance of hemostasis.

Solvent/detergent virus-inactivated plasma (VIP) contains markedly reduced protein S (PS) and alpha 2-antiplasmin (APL) beside other slightly decreased inhibitors. This could possibly be critical for the balance of hemostasis in diseases in which plasma inhibitors are reduced. A heterogeneous group of 14 patients with 18 plasma transfusions (12 FFP/24 VIP, 2 units per transfusion) was investigated. The patients suffered from dilution coagulopathy, liver disease, disseminated intravascular coagulation (DIC), hyperfibrinolysis, or received massive transfusions. Prothrombin fragment 1 + 2, fibrin monomers, D-Dimers, thrombin-AT III complexes, antiplasmin-plasmin complexes and fibrinogen degradation products as markers of activated coagulation (MAC) were measured. Blood samples were taken before and after plasma replacement. Significant differences between VIP and FFP should be recognized by comparing the ratio of MAC after/MAC before plasma transfusion. Patients showed an average inhibitor plasma level of AT III 51%, protein C 44%, PS 63%, and APL 52%. Only the F 1 + 2 ratio was obviously higher in the VIP group but not significantly. So the remaining MAC ratios did not show any significant difference. Our preliminary data showed no indication for a higher state of activation of coagulation in patients receiving VIP in comparison with those receiving FFP, if the VIP had the quality required. Solvent/detergent (SD) inactivation of transfusion-relevant viruses in plasma was successfully performed by Horowitz et al. [1]. The procedure leads to a partial reduction of the activity of clotting factors [2]. PS and APL are more severely affected. Therefore, treatment with VIP might activate or at least increase the activation of coagulation, especially in patients with reduced plasma inhibitors. To clarify this problem, the following disorders with the indication for plasma replacement were included in a prospective randomized study of FFP vs. VIP: massive transfusion; dilution coagulopathy; disturbance in liver synthesis; disseminated intravascular coagulation (DIC); primary hyperfibrinolysis. Low PS levels could induce hypercoagulability by reduced F VIII and FV inhibition, and low APL could induce hyperfibrinolysis by reduced plasmin inhibition.

[Preliminary results of a prospective randomized clinical study on the comparison of solvent- and detergent-inactivated plasma (SDP-TNBT/Triton X-100) and untreated fresh-frozen plasma]. / Erste Ergebnisse einer prospektiven randomisierten klinischen Studie zum Vergleich von Solvent-Detergent-inaktiviertem Plasma (SDP-TNBP/Triton X-100) und unbehandeltem Fresh-frozen-Plasma.

We report on preliminary results of a randomised clinical study comparing solvent/detergent-inactivated plasma to untreated FFP. Factors V, VII, VIII:C and protein S in the plasma units and in 14 patients were determined. Additionally, we measured prothrombin fragments 1,2, fibrin monomers, D-dimers, thrombin-antithrombin III, plasmin-antiplasmin complexes and fibrinogen degradation products as markers of activated coagulation (MAC), and calculated ratios of MACpost/ MACpre. One batch of SD plasma (SDP 797) with very high FVII and very low protein S seemed to produce significant changes in vivo without any clinical relevance. The bad quality of this batch could be due to virus inactivation in the early phase of large-scale routine production from a plasma pool that was too small.

[Risk assessment and diminution in preoperative autologous blood donation]. / Risikoabwägung und -minderung bei präoperativer Eigenblutspende.

Preoperative autologous blood donation is only indicated if a positive balance between benefit and risk can be struck. In this contribution the different aspects to be considered are described and valued. By a mathematical formula we try to correlate the different aspects somewhat more objectively. In addition, we define 4 risk groups by the state of health of the patients which allow to estimate the risk of the patient by blood donation more easily and help to reduce it by selection of the appropriate donation procedure.