Fondaparinux is a synthetic pentasaccharide that exerts its anticoagulant effect by binding to antithrombin III, inducing a conformational change that selectively inhibits activated factor X (Xa). Unlike unfractionated heparin or low molecular weight heparins, fondaparinux does not inhibit thrombin (factor IIa) and is too small to promote platelet activation, making the risk…
Carotid body tumors are vascular tumors arising from the carotid body’s paraganglion cells at the bifurcation of the internal and external carotid arteries (ICA and ECA, respectively). The Shamblin classification is used to categorize these tumors based on their involvement with adjacent structures, namely the ICA, ECA, common carotid artery…
Von Willebrand Factor (vWF) is a glycoprotein that serves as a “glue” between subendothelial collagen and platelets. More specifically: subendothelial collagen ↔ vWF’s A3 domain ↔ vWF’s A1 domain ↔ GPIb platelet receptor. vWF also stabilizes factor VIII in circulation. vWF is composed of subunits that link together (dimerize) and…
As a cardiothoracic anesthesiologist, hemostasis, coagulopathy, and blood salvation are important considerations in the operations I’m involved with. Cell Saver is one technique our perfusion team routinely utilizes to facilitate blood conservation. Blood loss on the surgical field is collected, run through a filter, washed, and returned to the patient…
We’ve all seen “type and screen” orders, but what does a blood type tell us?
Patients with liver cirrhosis often have low platelets (splenic sequestration) and elevated INRs due to decreased synthesis of factor VII, among other clotting factors; however, remember that they also have reduced synthesis of anticoagulant proteins like proteins C/S and antithrombin. The quantitative/qualitative platelet defects are offset to some degree by…
Enoxaparin (Lovenox) is a low molecular weight heparin (LMWH) routinely administered subcutaneously (SC) for prophylaxis or treatment of deep vein thrombosis, acute pulmonary embolism, and even medically-managed STEMIs (+/- percutaneous coronary interventions).
There are over 8 million Jehovah’s Witnesses (JWs) worldwide who routinely do not accept whole blood, packed red blood cells, fresh frozen plasma, platelets, or cryoprecipitate. This stems from their interpretation of Biblical scripture. This can present unique challenges to me in the OR and ICU during large cardiothoracic surgeries,…
Desmopressin (DDAVP, antidiuretic hormone) is a synthetic analog of vasopressin that can be administered IV, IM, subQ, and orally. Compared to vasopressin (generally regarded as a potent vasoconstrictor), DDAVP has less efficacy as a pressor, a longer duration, and is a much more potent antidiuretic (hence its use for bedwetting)…
Factor IX deficiency (hemophilia B) was first described in the 1950s by British doctors caring for a young boy. That child, who later went on to have a disease and clotting factor named in his honor, was Stephen Christmas.