Surfers’ 5 YEAR Anniversary! Retro to Feb 2011: Saturday Morning Brunch I

The European Contingent

A RETRO look at the second post on Circuit Surfers (Feb 25th 2011).  Where are all the RED dots? Editor’s Note: I chose the 2nd post because the 1st one was to put it mildly- somewhat embarrassing. It’s like re-reading something you wrote back in 6th grade embarrassing. What is NOT embarrassing, is that over […]

The “How & Why …” (1st Official ‘Surfers Post)

This is a forum for discussion, a reservoir for perfusion related information, trends, and updates. The intent of this blog is to allow the perfusion community to stay mainstream with current media innovations and directions. Any and all contributions are welcome, Article and post submissions are welcome as well. You can search for posts or […]

Angiomax

Angiomax Perfusion Issues Reconstitute Angiomax in OR- 250 mg in powder with 5 cc NSS=  50 mg per ml. No heparin coated surfaces (circuit, CDI, Swann Ganz– etc) Angiomax ½ life = 25 minutes Will precipitate if blood is allowed to pool Observed clot in the pericardium (after Angiomax is bolused)  is Normal- remove with […]

Myocardial Flow & Oxygen Supply

Myocardial Flow & Oxygen Supply   Vessels on the epicardial surface of the heart are considered to be conductance vessels and under normal conditions offer little resistance for blood flow and perfusion. The four factors influencing blood flow and resistance dynamics for intramural coronary vasculature are:  aortic root pressure, extravascular compression, myocardial metabolic requirement, and […]

Cardiac Conduction System

Normal Conduction System Function 1. To generate rhythmical impulses. 2. To conduct the impulses throughout the myocardium. Normal Conductive Tissue Specialized muscle tissue that is not or poorly contractile. Sinus node (SA Node) –pacemaker of the heart. Internodal pathways–conductive tissue from SA node through atrial muscle. Bachman’s bundle–interatrial internodal pathway–communicates with the right and left […]

Depolarization- Repolarization

Depolarization- Repolarization Resting membrane Potential (RMP) Electrical potential of cell at rest.  Above example is cardiac muscle tissue. Action Potential The five – phase process characterized by the movement of K+, Na, and Ca++( primarily) across cell membrane. Threshold potential (TP) The point at which a stimulus will initiate a response helps determine Automaticity of […]

Cryoprecipitate v1.0

Cryoprecipitate Cryoprecipitate contains 2 or more times the concentration of fibrinogen contained in plasma as well as increased levels of factor V and factor VIII.   Each unit however, contains only 50 ml, thus conceivably requiring several units of cryoprecipitate to be administered in order to achieve target ranges (>150 mg/dl) for depleted fibrinogen levels.  This […]

Desmopressin v.1

Desmopressin Desmopressin acetate (DDAVP) is a synthetic analog of vasopressin and like ADH, epinephrine, and insulin, releases a variety of hemostatically active substances from vascular endothelium.  It is administered in doses of 0.3 µg/kg by intravenous, intranasal, or subcutaneous routes.  It has a half life of 55 minutes, (with clinical effects lasting from 5 to […]

Protamine v1

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 […]

Aortic Stenosis v.1

Aortic Stenosis Rheumatic heart disease and calcification deposits due to age (senile calcific aortic stenosis) are the most common pathologic conditions associated with aortic stenosis.  Congenital malformations such as a bicuspid aortic valve with a small annulus, or unicuspid valve usually develop symptoms at an early age but occasionally surface in later years.  Calcification of […]

Cardiac Blood Flow & O2 Consumption v1.0

Cardiac Blood Flow & O2 Consumption   Source: Cardiovascular Physiology Concepts Richard E. Klabunde, PhD The major vessels of the coronary circulation are the left main coronary that divides into left anterior descending andcircumflex branches, and the right main coronary artery. The left and right coronary arteries originate at the base of the aorta from openings called the coronary ostia located behind […]

Intracardiac Shunts v1.0

Principles of Intracardiac Shunts With the continued presence of a congenital defect of the cardiac septum or great vessels in which there is a communication between the left and right cardiac structures, blood flow is diverted from the area of greater resistance to the chamber or vessel of least resistance.  As a result, a percentage […]

Mitral Insufficiency v.1

Mitral Insufficiency Six anatomical components must mesh synchronously to insure proper function of the mitral valve.  Disruption of the kinetic interrelationship between the left ventricular wall, the left atrial wall, valve leaflets, annulus, chordae tendineae, and papillary muscles, may lead to dysfunction of the valve.  Chronic mitral valve insufficiency (regurgitation) most often results from rheumatic […]

Myocardial Ischemia v.1

Myocardial Ischemia Prevention and treatment of perioperative myocardial ischemia is a primary consideration.  Two consistent factors associated with the pathogenesis of myocardial ischemia are inadequate oxygen supply to the myocardium due to localized coronary lesions, and excessive oxygen demand due to increased hemodynamic workload associated with increased heart rate, blood pressure, or adrenergic stimulation of […]

Myocardial Oxygen Demand

Myocardial Oxygen Demand   The heart extracts more oxygen than other tissues while at rest (50-70%).  The heart’s normal compensation for increased oxygen demand is to increase coronary blood flow (400-600%).  Because cardiac tissue extracts at twice the rate of other tissues and since normal compensation for anemic states involves increased cardiac output, the heart […]

Right Ventricular Function v. 1

Right Ventricular Function Patients with right coronary artery disease may be susceptible to right ventricular ischemia and infarction when right ventricular distension or increased afterload occurs resulting in diminished cardiac performance and reduced right coronary perfusion pressure.  The interrelationships of aortic end-diastolic pressure, afterload volume, coronary perfusion pressure, and pulmonary vascular resistance, play a significant […]

Serotonin

Serotonin Serotonin functions as a neurotransmitter, is synthesized in the gastrointestinal mucosa, and is stored primarily in platelets and the endothelium of the lungs and central nervous system.  It’s role in the central regulation of blood pressure is mediated by receptors and is subsequently dependent on their availability.  In large arteries, serotonin combined with S2 […]

AT3 Deficiency v.1

Antithrombin III (AT III) is a plasma glycoprotein with a molecular weight of 58,000 daltons.  AT III deficiency may be noticed when the patient’s activated clotting time (ACT) does not respond to heparin administration as would be expected when given a standard dosage.  Also can be confirmed by a laboratory value of the patient’s AT […]

Cold Agglutinins v.1

I.    BACKGROUND: Hypothermic cardiopulmonary bypass with the use of cold blood cardioplegia carries with it the risk of red cell agglutination caused by unsuspected cold agglutinin disease.  Patients with this condition possess serum antibodies which become reactive at temperatures usually less than 30°C and are directed against an antigen of the human erythrocyte causing agglutination […]

HIT

Heparin Induced Thrombocytopenia I.    DESCRIPTION: Heparin induced thrombocytopenia (HIT) and heparin induced thrombocytopenia thrombosis syndrome (HITTS) are immune mediated complications of heparin therapy.  An antibody, produced by the body upon initial exposure to     heparin, reacts with an antigen upon re-exposure or continuous exposure to heparin. HIT is characterized by a dramatic decrease in platelet […]

Protamine Reaction v1

I.    DESCRIPTION: Following cardiopulmonary bypass with heparin anticoagulation, protamine sulfate is used to neutralize the effects of heparin and reverse anticoagulation.  Currently protamine is the only drug available in the United States that can be used for this purpose. Hexadimethrine bromide (Polybrene) and toluidine blue are for laboratory use only. II.    ADMINISTRATION: The method of […]

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%. […]

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 […]

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 […]

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 […]

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 […]

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.  […]

Fibrinolysisv.1.0

Fibrinolysis Fibrinolysis is the dissolution of the clot formation process involving the plasma protein plasminogen.  This system of enzymes dissolves blood clots by the lysis of fibrin.  Fibrinolysis plays a role as well in other biological processes such as tissue repair, macrophage activation and function, ovulation, and embryo implantation.  Fibrinolysis is mediated by plasmin and […]

Heparin (v.1)

HEPARIN   ONSET:   Maximal at 1 minute past atrial delivery: Measured at radial artery.  Note:  10-20% reduction in svr without affecting c.o. and or h.r.   LUNG VS MUCOSAL:   Mucosal requires larger doses- but can be reversed with 25-30% less protamine:  greater postoperative blood loss associated with mucosal heparin- speculated to result from […]

Hemostasis Assays [v.1]

Partial Thromboplastin Time (Activated) The activated partial thromboplastin time (aPTT) is test that overlaps the prothrombin time (both evaluate the common pathway), and is designed to isolate the intrinsic pathway.  While these tests are similar, the aPTT utilizes kaolin or cellite and cephaloplastin to stimulate the intrinsic pathway.  This pathway is the longer of the […]

Activated Clotting Time (ACT)

Activated Clotting Time (ACT) The ACT is a standardized measurement of the patients procoagulation or anticoagulation level.  The unit of measurement is the time (in seconds) that is required for an ACT counter to detect the formation of blood clot in a 2-3 milliliter sample of whole blood.  Normal ACT levels range from 100-130 seconds, […]

Coagulopathies & Treatment

Coagulopathies & Treatment The most common cause of intraoperative coagulopathy is thrombocytopenia (decrease in platelet count) secondary to hemodilution.  Blood loss that is replaced by crystalloid volume will progressively dilute platelet numbers as well as platelet entrapment on the surfaces of the extracorporeal circuit.  Associated with bypass is platelet migration to the spleen and reticuloendothelial […]

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, […]