Circuit Surfers

The Currents, Eddys & Riptides- of Open-Heart Surgery

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The Extracorporeal Circuit v.1

The Extracorporeal Circuit Diversion of blood from the operative site, via an extracorporeal circuit (ECC) is necessary to proceed with open heart surgery .  Vascular access leading to the right side of the heart (venous) and ejecting from the left side of the heart (arterial) is shunted from the patient to the heart lung machine. …

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Protamine

Protamine Protamine, a polycationic protein derived from salmon milt, possess strong alkalinity because of an amino acid composition consisting of 67% arginine.  In its natural state, the numerous positive charges on the protamine molecule bind with the negatively charged phosphate groups of the nucleoprotein material of salmon sperm.  Heparin, a polyanion, binds ionically to protamine…

Factors

Clotting Factors & Synonyms

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Coagulopathies

Coagulopathies The most common cause of intraoperative coagulopathy is thrombocytopenia secondary to hemodilution.  Thrombocytopenia is a condition where the circulating platelet count falls below 50,000 platelets per microliter.  As a result of such low circulating platelet levels, people have bleeding tendencies similar to those experienced by hemophiliacs (deficiency of Factor VIII), except that bleeding occurs…

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Common Pathway (Coagulation)

The endpoint of activity for both the extrinsic and intrinsic pathways for coagulation is the activation of factor X.  Reactions beyond this point are common to both pathways, and involves the combining of activated factor X with procoagulants (factor II, factor V, calcium ions, and platelet phospholipids) to form a prothrombinase complex.  This complex catalyzes…

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Jehovah’s Witness v.1

JEHOVAH’S WITNESSES Jehovah’s Witness patients are at increased risk for morbidity and mortality associated with blood loss due to their refusal, on religious grounds, of both homologous blood transfusion and autologous blood that has been removed from  continuity with the body.  They believe that it is wrong to accept or receive any type of blood…

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Malignant Hyperthermia v 1

I.    PATHOPHYSIOLOGY: Malignant hyperthermia (MH) is a pharmacogenetic disorder characterized by a fulminant hypermetabolic reaction of skeletal muscle induced by volatile inhalational anesthetics, succinylcholine, and possibly stress and exercise.  Until the advent of dantrolene, the mortality rate was 65% but since the introduction of dantrolene in 1979, it has decreased to between 1 and 10%.…

Coag

Coagulation Cascade (V.1)

  Intrinsic Pathway The coagulation cascade is initiated when blood becomes traumatized by exposure to a foreign surface.  An example of this is the initiation of cardiopulmonary bypass.  Blood contact with the polyvinyl chloride tubing utilized in the extracorporeal circuit, the squeezing mechanism of the roller head pump, and various applications of blood filtering devices,…