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Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer's lactate on blood loss and coagulation after cardiac surgery

BACKGROUND Infusion of 5% human albumin (HA) and 6% hydroxyethyl starch 130/0.4 (HES) during cardiac surgery expand circulating volume to a greater extent than crystalloids and would be suitable for a restrictive fluid therapy regimen. However, HA and HES may affect blood coagulation and could contribute to increased transfusion requirements. METHODS We randomly assigned 240 patients undergoing elective cardiac surgery to receive up to 50 ml kg(-1) day(-1) of either HA, HES, or Ringers lactate (RL) as the main infusion fluid perioperatively. Study solutions were supplied in identical bottles dressed in opaque covers. The primary outcome was chest tube drainage over 24 h. Blood transfusions, thromboelastometry variables, perioperative fluid balance, renal function, mortality, intensive care unit, and hospital stay were also assessed. RESULTS The median cumulative blood loss was not different between the groups (HA: 835, HES: 700, and RL: 670 ml). However, 35% of RL patients required blood products, compared with 62% (HA) and 64% (HES group; P=0.0003). Significantly, more study solution had to be administered in the RL group compared with the colloid groups. Total perioperative fluid balance was least positive in the HA group [6.2 (2.5) litre] compared with the HES [7.4 (3.0) litre] and RL [8.3 (2.8) litre] groups (P<0.0001). Both colloids affected clot formation and clot strength and caused slight increases in serum creatinine. CONCLUSIONS Despite equal blood loss from chest drains, both colloids interfered with blood coagulation and produced greater haemodilution, which was associated with more transfusion of blood products compared with crystalloid use only.

Patients With Severe Aortic Valve Stenosis and Impaired Platelet Function Benefit From Preoperative Desmopressin Infusion

BACKGROUND Patients with severe aortic valve stenosis have a markedly reduced platelet function as measured by a prolonged collagen adenosine diphosphate closure time (CADP-CT) determined by the platelet function analyzer PFA-100. We hypothesized that such patients may benefit from desmopressin when they present with prolonged CADP-CT due to the specific action of desmopressin on von Willebrand factor (VWF) and CADP-CT. METHODS In this double-blind, randomized placebo controlled trial, 43 patients undergoing aortic valve replacement (due to severe aortic valve stenosis with CADP-CT>170 seconds) were given desmopressin 0.3 μg/kg or saline intravenously after induction of anesthesia. Measurement of CADP-CT, factor VIII activity, von Willebrand factor antigen, GpIb binding activity, ristocetin cofactor activity, collagen-binding activity, and multimers were performed after induction of anesthesia, one hour after desmopressin infusion, and 24 hours postoperatively. RESULTS In the majority of patients, baseline values of von Willebrand factor related indices were normal, but increased one hour after infusion of desmopressin by 73% to 90% as compared with placebo. Selective loss of high molecular weight multimers was seen only in a minority of patients. The CADP-CT was greater than 170 seconds in 92% of screened patients, and desmopressin shortened CADP-CT by 48% versus baseline and reduced postoperative blood loss by 42% (p<0.001). CONCLUSIONS Prolonged CADP-CT indicates platelet dysfunction in severe aortic valve stenosis, and can guide the use of desmopressin as an effective prohemostatic agent in patients with severe aortic valve stenosis.

Efficacy and Safety of Hydroxyethyl Starch 6% 130/0.4 in a Balanced Electrolyte Solution (Volulyte) During Cardiac Surgery

OBJECTIVE The infusion of large amounts of saline-based solutions may contribute to the development of hyperchloremic metabolic acidosis and the use of a balanced carrier for colloid solutions might improve postoperative acid-base status. The equivalence of 2 hydroxyethyl starch (HES) solutions and the influence on chloride levels and acid-base status by selectively changing the carrier of rapidly degradable modern 6% HES 130/0.4 were studied in cardiac surgery patients. DESIGN A prospective, randomized, double-blinded study. SETTING A clinical study in 2 cardiac surgery institutions. PARTICIPANTS Eighty-one patients. INTERVENTION Patients received either 6% HES130/0.4 balanced (Volulyte; Fresenius Kabi, Bad Homburg, Germany) or 6% HES130/0.4 saline (Voluven; Fresenius Kabi, Bad Homburg, Germany) for intra- and postoperative hemodynamic stabilization. MEASUREMENTS AND MAIN RESULTS The therapeutic equivalence of both HES formulations regarding volume effect and superiority of the balanced electrolyte solution regarding serum chloride levels and acid-base status were measured. Similar volumes of both HES 130/0.4 balanced and HES 130/0.4 saline were administered until 6 hours after surgery, 2,391 ± 518 mL in the HES 130/0.4 balanced group versus 2,241 ± 512 mL in the HES 130/0.4 saline group. The 95% confidence interval for the difference between treatments (-77; 377 mL; mean, 150 mL) was contained entirely in the predefined interval (-500, 500 mL), thereby proving equivalence. The serum chloride level (mmol/L) was lower (p < 0.05 at the end of surgery), and arterial pH was higher in the balanced group at all time points except baseline, and base excess was less negative at all time points after baseline (p < 0.01). CONCLUSIONS Volumes of HES needed for hemodynamic stabilization were equivalent between treatment groups. Significantly lower serum chloride levels in the HES balanced group reflected the lower chloride load of similar infusion volumes. The HES balanced group had significantly less acidosis.

Effect of Preload Alterations on Left Ventricular Systolic Parameters Including Speckle-Tracking Echocardiography Radial Strain During General Anesthesia

OBJECTIVES Frequently used parameters for evaluation of left ventricular systolic function are load-sensitive. However, the impact of preload alterations on speckle-tracking echocardiographic parameters during anesthesia has not been validated. Therefore, two-dimensional (2D) speckle-tracking echocardiography radial strain (RS) was assessed during general anesthesia, simulating 3 different preload conditions. DESIGN Single-center prospective observational study. SETTING University hospital. PARTICIPANTS Thirty-three patients with normal left ventricular systolic function undergoing major surgery. INTERVENTIONS Transgastric views of the midpapillary level of the left ventricle were acquired at 3 different positions. MEASUREMENTS AND MAIN RESULTS Fractional shortening (FS), fractional area change (FAC), and 2D speckle-tracking echocardiography RS were analyzed in the transgastric midpapillary view. Considerable correlation above 0.5 was found for FAC and FS in the zero and Trendelenburg positions (r = 0.629, r = 0.587), and for RS and FAC in the anti-Trendelenburg position (r = 0.518). In the repeated-measures analysis, significant differences among the values measured at the 3 positions were found for FAC and FS. For FAC, there were differences up to 2.8 percentage points between the anti-Trendelenburg position and the other 2 positions. For FS, only the difference between position zero and anti-Trendelenburg was significant, with an observed change of 1.66. Two-dimensional RS was not significantly different at all positions, with observed changes below 1 percentage point. CONCLUSIONS Alterations in preload did not result in clinically relevant changes of RS, FS, or FAC. Observed changes for RS were smallest; however, the variation of RS was larger than that of FS or FAC.

Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer’s lactate: Reply to Prof Priebe

trations of 0.06 and 0.02 mg dl in the HA and HES groups, respectively, are clinically irrelevant. Apart from these major limitations, there are additional issues. (i) The findings apply to a highly selected population. Of initially 2548 screened patients, only 240 (,10%) were included in the study. (ii) This is a study of non-consecutive patients. For? ‘logistic’ reasons, 620 patients (24%) were not included. The definition of logistic reason is not provided. The exact time period during which the study was performed is not specified. (iii) An a priori power calculation indicated that 80 patients per group were required. In fact, the HA and RL groups consisted of only 76 and 79 patients, respectively. Strictly speaking, the study is underpowered. (iv) Fluid administration was not goal-directed. Although the ‘impact of fluid loading’ on myocardial performance was monitored by transoesophageal echocardiography, fluids were administered ‘as required’ and ‘at the discretion of the attending consultant and not controlled by protocol’. (v) Decisions on the administration of fresh frozen plasma and platelets were based on thromboelastography, a purely ex vivo coagulation test which does not necessarily reflect clinical bleeding. Several recent meta-analyses (including several investigations in cardiac surgery patients) did not find any association between HES containing solutions and renal dysfunction, – 7 increased blood loss and allogeneic erythrocyte transfusion in surgical patients. In view of the numerous considerable methodological problems, the validity of the findings by Skhirtladze and colleagues is questionable.