We evaluated the effect of various hydroxyethyl starch (HES) solutions on platelet function. Blood was obtained before and after the IV infusion (10 mL/kg) of saline (n = 10), HES 70/0.5--0.55 (molecular weight in kD/degree of substitution; n = 10), HES 130/0.38--0.45 (n = 10), HES 200/0.6--0.66 (n = 10), or HES 450/0.7--0.8 (n = 10) in otherwise healthy patients scheduled for elective surgery. Collagen and epinephrine were used as agonists for assessment of platelet function analyzer closure times. Flow cytometry was used to assess agonist-induced expression of activated glycoprotein IIb/IIIa complex and P-selectin. Infusion of HES 450/0.7--0.8, HES 200/0.6--0.66, and HES 70/0.5--0.55 prolonged closure times and reduced glycoprotein IIb/IIIa expression, whereas saline and HES 130/0.38--0.45 had no significant effect on platelet variables. P selectin expression was not affected by any solution tested. In vitro experiments demonstrated a less inhibiting effect of HES 130/0.38--0.45 on closure times when compared with other HES solutions. This study shows that HES 450/0.7--0.8, HES 200/0.6--0.66, and HES 70/0.5--0.55 inhibit platelet function by reducing the availability of the functional receptor for fibrinogen on the platelet surface. Our data indicate that fluid resuscitation with HES 130/0.38--0.45 may reduce the risk of bleeding associated with synthetic colloids of higher molecular weight and degree of substitution.

Ultrasound guidance for sciatic and femoral nerve blocks in children increased the duration of sensory blockade in comparison with nerve stimulator guidance. Prolonged sensory blockade was achieved with smaller volumes of local anaesthetic when using ultrasound guidance.

Accurate placement of local anesthetic around the ilioinguinal/iliohypogastric nerves in children is seldom possible when landmark-based techniques are used. In the majority of patients, the local anesthetic was inaccurately placed in adjacent anatomical structures with unpredictable block results.

We evaluated the effects of hydroxyethyl starch with a molecular weight of 200 kD (HES 200 kD) on platelets to gain insight into the potential mechanisms involved in the anticoagulant effects of HES 200 kD. Blood was obtained before and after an IV infusion (10 mL/kg) of either saline (n = 15) or HES 200 kD (n = 15) in otherwise healthy patients scheduled for minor elective surgery. Flow cytometry was used to assess the expression of glycoprotein (GP) IIb-IIIa, GP Ib, and P-selectin on agonist-activated platelets. Overall platelet function was evaluated by assessing thromboelastographic maximum amplitude (MA) in celite-activated blood and platelet function analyzer-closure times by using collagen/adenosine diphosphate cartridges. Saline infusion had no effects on platelet variables, whereas HES 200 kD reduced GP IIb-IIIa expression and MA and prolonged platelet function analyzer-closure times, without affecting the expression of P-selectin and GP Ib. In vitro experiments extended these observations by a concentration-related inhibiting effect of HES 200 kD on GP IIb-IIIa expression. This study demonstrates that cellular abnormalities with decreased availability of platelet GP IIb-IIIa are involved in the anticoagulant effects of HES 200 kD.

Thawed S/D-treated plasma stored at +4 degrees C for up to 6 days still contains sufficient coagulation activities and plasma proteins to be regarded as suitable for transfusion in the established indications.