Sibylle A. Kozek-Langenecker

Introduction: The appropriate strategy for trauma-induced coagulopathy management is under debate. We report the treatment of major trauma using mainly coagulation factor concentrates. Methods: This retrospective analysis included trauma patients who received ≥ 5 units of red blood cell concentrate within 24 hours. Coagulation management was guided by thromboelastometry (ROTEM^®). Fibrinogen concentrate was given as first-line haemostatic therapy when maximum clot firmness (MCF) measured by FibTEM (fibrin-based test) was 1.5 times normal. Lack of improvement in EXTEM MCF after fibrinogen concentrate administration was an indication for platelet concentrate. The observed mortality was compared with the mortality predicted by the trauma injury severity score (TRISS) and by the revised injury severity classification (RISC) score. Results: Of 131 patients included, 128 received fibrinogen concentrate as first-line therapy, 98 additionally received PCC, while 3 patients with recent coumarin intake received only PCC. Twelve patients received FFP and 29 received platelet concentrate. The observed mortality was 24.4%, lower than the TRISS mortality of 33.7% (P = 0.032) and the RISC mortality of 28.7% (P > 0.05). After excluding 17 patients with traumatic brain injury, the difference in mortality was 14% observed versus 27.8% predicted by TRISS (P = 0.0018) and 24.3% predicted by RISC (P = 0.014). Conclusions: ROTEM^®-guided haemostatic therapy, with fibrinogen concentrate as first-line haemostatic therapy and additional PCC, was goal-directed and fast. A favourable survival rate was observed. Prospective, randomized trials to investigate this therapeutic alternative further appear warranted.

(2010). Peri-operative diagnosis and treatment of platelet disorders. Southern African Journal of Anaesthesia and Analgesia: Vol. 16, No. 1, pp. 55-56.

The present review of fluid therapy studies using balanced solutions versus isotonic saline fluids (both crystalloids and colloids) aims to address recent controversy in this topic. The change to the acid-base equilibrium based on fluid selection is described. Key terms such as dilutional-hyperchloraemic acidosis (correctly used instead of dilutional acidosis or hyperchloraemic metabolic acidosis to account for both the Henderson-Hasselbalch and Stewart equations), isotonic saline and balanced solutions are defined. The review concludes that dilutional-hyperchloraemic acidosis is a side effect, mainly observed after the administration of large volumes of isotonic saline as a crystalloid. Its effect is moderate and relatively transient, and is minimised by limiting crystalloid administration through the use of colloids (in any carrier). Convincing evidence for clinically relevant adverse effects of dilutional-hyperchloraemic acidosis on renal function, coagulation, blood loss, the need for transfusion, gastrointestinal function or mortality cannot be found. In view of the long-term use of isotonic saline either as a crystalloid or as a colloid carrier, the paucity of data documenting detrimental effects of dilutional-hyperchloraemic acidosis and the limited published information on the effects of balanced solutions on outcome, we cannot currently recommend changing fluid therapy to the use of a balanced colloid preparation.

Rotational thromboelastometry ROTEM® is available as point-of-care coagulation monitoring in an increasing number of European operating theatres and emergency rooms. The Platelet Mapping™ Assay has been described as a platelet aggregation assay for thromboelastography TEG®. The aim of this experimental trial was to evaluate feasibility of the Platelet Mapping™ Assay on the ROTEM® test system. Whole blood was drawn from 22 adult volunteers and patients with and without antiplatelet medication. Platelet aggregability was determined in three whole blood assays: the Platelet Mapping™ Assay using both activators arachidonic acid (AA) and adenosine diphosphate (ADP) on TEG®, its adapted version on ROTEM®, and the multiple electrode impedance aggregometer Multiplate®. Percent aggregation inhibition results were plotted in a linear regression analysis and correlation was estimated. Sensitivity and specificity for detecting antiplatelet medication were determined. Overall correlations were statistically significant with an r² = 0.83 in AA-activated and an r² = 0.82 in ADP-activated Platelet Mapping™ Assay. AA-activated tests and the Multiplate® analysis identified aspirin-inhibition in 86% and 100%, respectively. ADP-activated tests and the Multiplate® analysis identified clopidogrel-inhibition in 67% and 89%, respectively. Specificity was low both in ROTEM® and TEG®. Differences in frequency distribution between the results obtained in ROTEM® and TEG® were not statistically significant. The Platelet Mapping™ Assay can be performed on the ROTEM®. For the perioperative scenario, however, longer test duration and higher costs have to be considered compared to Multiplate® analyses.

Pre- and intraoperative platelet function monitoring is increasingly recommended in order to detect risk factors for bleeding and to target coagulation management. The ideal anticoagulant for accurate platelet aggregometry remains controversial. The aim of this experimental trial was to compare platelet aggregability in whole blood stored in citrate, heparin and direct thrombin inhibitors. Whole blood was drawn from 11 healthy adult volunteers who had not taken any medication in the previous 14 days. Blood was stored in trisodium citrate, unfractionated heparin, melagatran, lepirudin and argatroban. Platelet aggregation was performed using the impedance aggregometer Multiplate® (Dynabyte, Munich, Germany) with adenosine diphosphate (ADP), thrombin receptor activating peptide (TRAP), collagen, arachidonic acid and ristocetin as agonists. Samples were analysed immediately after blood sampling (baseline), as well as 30 and 120 min afterwards. At baseline there were no significant differences in aggregability between samples containing direct thrombin inhibitors and heparin. In contrast, aggregation in response to all agonists except for ristocetin was significantly impaired in citrated blood. During storage the response to arachidonic acid and collagen was maintained by direct thrombin inhibitors and heparin, whereas ADP-, TRAP- and ristocetin-induced aggregation varied considerably over time in all ex vivo anticoagulants tested. Pre-analytical procedures should be standardized because storage duration and anticoagulants significantly affect platelet aggregability in whole blood. For point-of-care monitoring with immediate analysis after blood withdrawal all tested direct thrombin inhibitors as well as unfractionated heparin can be used as anticoagulants whereas citrate is not recommended.

The effects of different types of hydroxylethyl starch (HES) on blood coagulation closely depend on their physicochemical properties. HES with lower molar substitution and a lower in vivo molecular weight interferes relatively little with hemostasis and therefore results in lower perioperative blood losses and red blood cell (RBC) transfusion. To test this hypothesis, we analyzed pooled data from all available studies in major surgery comparing 6% HES 130/0.4 and 6% HES 200/0.5 from waxy maize starch. Estimated blood loss, drainage loss, calculated blood loss, transfused blood product volumes, and coagulation variables were examined for 24 h after the start of surgery. Groups were compared using analysis of variance, evaluating several covariates. Four-hundred-forty-nine patients from seven clinical trials were analyzed, 228 received HES 130/0.4, and 221 received HES 200/0.5. For HES 130/0.4 patients, when compared to HES 200/0.5 patients, the estimated blood loss was reduced by 404 mL [P = 0.006], drainage loss was 272 mL less [P = 0.009], and calculated RBC loss was 149 mL less [P = 0.003]. RBC transfusion volumes were also lower for HES 130/0.4 by 137 mL [P = 0.004]. In the early postoperative phase, HES 130/0.4 was found to exert significantly less effect on measures of coagulation, especially activated partial thromboplastin time and von Willebrand factor (antigen and ristocetin cofactor), than HES 200/0.5. Blood loss and transfusion requirements can be significantly reduced in major surgery when using third generation HES 130/0.4 (Voluven) compared to second generation waxy maize starch HES 200/0.5. Since HES 130/0.4 and HES 200/0.5 were found similar regarding volume efficacy in other studies, HES 130/0.4 is recommended in this clinical setting.