Koagulopathie

Perioperative coagulopathy monitoring

Coagulopathy is common in orthopedic surgery patients either due to acquired factors, such as surgery, trauma, medications, or hemorrhage. Perioperative monitoring of blood coagulation is critical to diagnose the causes of hemorrhage, guide hemostatic therapies, predict the risk of bleeding during surgical procedures, and reduce risk of postoperative cardiac and thromboembolic events. In contrast to previous interventions that measure specific portions of the clotting cascade (such as intrinsic or extrinsic pathways or platelet aggregation), "Point-of-care" coagulation monitoring devices assess the viscoelastic properties of whole blood. These techniques have the potential to measure the entire clotting process, starting with fibrin formation, clot retraction, and fibrinolysis. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red cells, and thereby providing useful additional information on platelet function. Improved monitoring of coagulopathy is particularly important as new anticoagulant drugs emerge that affect the clotting cascade in novel ways, including the inhibition of intrinsic and extrinsic pathways and platelet function. It is important for orthopedic surgeons to understand the pharmacology and reversal of these drugs in the perioperative setting. The purpose of this review is to review the current techniques to monitoring perioperative coagulopathy and to identify the manner in which novel anticoagulant medications affect the clotting cascade with particular interest in trauma and spine surgery.

[Treatment of polytrauma in the intensive care unit]

The treatment of severely injured trauma patients (polytrauma) is one of the outstanding challenges in medical care. Early in the initial course the patient's diagnostics have to be scrupulously reevaluated by an interdisciplinary team (tertiary trauma survey) to reduce deleterious sequelae of missed injuries after the initial assessment. Severely injured patients stay in intensive care for an average of 11 days. During this time the patient's therapy has to ensure a high quality evidence-based intensive care treatment and simultaneously has to be tailored to the current individual injuries. Because of the fact that the damage control strategy is gaining increasing acceptance, the intensive care unit plays a pivotal role in the critical time between emergency and elective surgery. Therefore a close cooperation between physicians of the intensive care unit and all surgical disciplines involved is essential to reach the aim of therapeutic efforts. After survival of emergency treatment patients with severe trauma should be reintegrated into social and occupational life as soon as possible.

Effects of desmopressin on platelet function under conditions of hypothermia and acidosis: an in vitro study using multiple electrode aggregometry*

SUMMARY

Hypothermia and acidosis lead to an impairment of coagulation. It has been demonstrated that desmopressin improves platelet function under hypothermia. We tested platelet function ex vivo during hypothermia and acidosis. Blood samples were taken from 12 healthy subjects and assigned as follows: normal pH, pH 7.2, and pH 7.0, each with and without incubation with desmopressin. Platelet aggregation was assessed by multiple electrode aggregometry. Baseline was normal pH and 36 degrees C. The other samples were incubated for 30 min and measured at 32 degrees C. Acidosis significantly impaired aggregation. Desmopressin significantly increased aggregability during hypothermia and acidosis regardless of pH, but did not return it to normal values at low pH. During acidosis and hypothermia, acidosis should be corrected first; desmopressin can then be administered to improve platelet function as a bridge until normothermia can be achieved.

Diagnosis and treatment of peripartum bleeding

Severe peripartum hemorrhage (PPH) contributes to maternal morbidity and mortality and is one of the most frequent emergencies in obstetrics, occurring at a prevalence of 0.5-5.0%. Detection of antepartum risk factors is essential in order to implement preventive measures. Proper training of obstetric staff and publication of recommendations and guidelines can effectively reduce the frequency of PPH and its resulting morbidity and mortality. Therefore, an interdisciplinary expert committee was formed, with members from Germany, Austria, and Switzerland, to summarize recent scientific findings. An up-to-date presentation of the importance of embolization and of the diagnosis of coagulopathy in PPH is provided. Furthermore, the committee recommends changes in the management of PPH including new surgical options and the off-label use of recombinant factor VIIa.