waring blender syndrome definition
Word not found in the Dictionary and Encyclopedia. Please try the words separately: Some articles that match your query: Waring's prime number conjecture Wario Land (Virtual Boy) Peripheral blood smear: patient with thrombotic thrombocytopenic purpura A schistocyte or schizocyte (from Greek schistos for "divided" or schistein for "to split", and kytos for "hollow" or "cell") is a fragmented part of a red blood cell. Schistocytes are typically irregularly shaped, jagged, and have two pointed ends. A true schistocyte does not have central pallor.[1] Schistocytes are sometimes referred to as "helmet cells". Several microangiopathic diseases, including disseminated intravascular coagulation and thrombotic microangiopathies, generate fibrin strands that sever red blood cells as they try to move past a thrombus, creating schistocytes. Schistocytes are often seen in patients with hemolytic anemia. They are frequently a consequence of mechanical artificial heart valves and hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, among other causes.
This is due to their abnormal shape which can cause them to undergo hemolysis or be removed by macrophages in the spleen.
hamilton beach 51103 single serve blender with travel lid Schistocyte formation occurs as a result of mechanical destruction (fragmentation hemolysis) of a normal red blood cell.
margaritaville blender qvcThis occurs when there is damage to the blood vessel and a clot begins to form. The formation of the fibrin strands in the vessels occurs as part of the clot formation process. The red blood cells get trapped in the fibrin strands and the sheer force of the blood flow causes the red blood cell to break. The resulting fragmented cell is called the schistocyte. A normal schistocyte count for a healthy individual is <0.5% although usual values are found to be <0.2%. A schistocyte count of >1% is most often found in thrombotic thrombocytopenic purpura, although they are more often seen within the range of 3-10% for this condition.
A schistocyte count of <1% but greater than the normal value is suggestive of disseminated intravascular coagulation, but is not an absolute diagnosis. The standard for a schistocyte count is a microscopic examination of a peripheral blood smear. Conditions that present with schistocytes on a peripheral blood smear include microangiopathic hemolytic anemia, traumatic hemolytic anemia, Waring Blender syndrome, Heart-valve hemolysis, disseminated intravascular coagulation, severe burns, and uremia. In most of the conditions, schistocytes are formed by fibrin formation and entrapment of red blood cells leading to fragmentation due to the force of blood flow in the vessels. Disseminated intravascular coagulation or DIC is caused by a systemic response to a specific condition including sepsis and severe infection, malignancy, obstetric complications, massive tissue injury, or systemic diseases. Disseminated intravascular coagulation is an activation of the coagulation cascade which is usually a result of an increased exposure to tissue factor.
The activation of the cascade leads to thrombi formation which causes an accumulation of excess fibrin formation in the intravascular circulation. The excess fibrin strands cause mechanical damage to the red blood cells resulting in schistocyte formation and also thrombocytopenia and consumption of clotting factors. Schistocyte values between .5% and 1% are usually suggestive of DIC. Thrombotic thrombocytopenic purpura or TTP is caused by primary platelet activation. Thrombotic thrombocytopenic purpura leads to increased amounts of large von Willebrand factor which then attach to activated platelets and mediate further platelet aggregation. Platelets end up being removed and the resulting fibrin strand formation remains. These fibrin strands along with the stress from the blood flow cause fragmentation of the red blood cells, leading to schistocyte formation. In TTP, a schistocyte count between 3-10% is common, but >1% is suggestive of the disease. Leaky prosthetic heart valves and other cardiac assisted devices can lead to microangiopathic hemolytic anemia, thrombocytopenia, and schistocyte formation.
The force from the blood flow over the high pressure gradient from the prosthesis leads to fragmentation of red cells, and schistocyte formation. This is rare and only occurs in about 3% of patients. Haemolytic-uremic syndrome or HUS is haemolytic anaemia, acute kidney failure (uraemia), and thrombocytopenia. HUS is caused by E. coli bloody diarrhea and specific strains of shiga toxin. The bacteria in HUS cause damage to the endothelium which results in platelet activation and formation of microthrombi. Red cells get trapped in the fibrin strands of the microthrombi and become sheared by the force of blood flow leading to schistocyte formation. ^ Amanda Cox et al., Schistocytes: A Brief Overview. Retrieved 23 August 2008.Acquired von Willebrand Syndrome (AVWS) is a well recognized phenomenon in children with congenital heart disease (CHD) (Federici & Mannucci, 2003). AVWS is a bleeding disorder similar to von Willebrand disease (VWD) in terms of laboratory findings and clinical severity (Mohri, 2003), and usually occurs in individuals with no personal or family history of a bleeding diathesis (Hennessy et al, 1998).
It is characterized by mucocutaneous and/or gastrointestinal bleeding, a prolonged bleeding time, and low plasma levels of factor VIII (FVIII)/von Willebrand Factor (VWF) measurements (Franchini & Lippi, 2007). AVWS has been reported in conditions with a reduced rate of VWF synthesis (Rauch et al, 2001); an accelerated clearance and resultant abnormality of VWF; and the development of anti-VWF autoantibodies that either interfere with VWF function or promote the rapid clearance of VWF (Rauch et al, 2001).The underlying pathophysiology in AVWS in patients with CHD is thought to result from increased clearance of the largest VWF multimers due to turbulent forces within the abnormal cardiac anatomy and/or increased cardiac output (Gill et al, 1986). After surgical correction of the cardiac defect the multimer pattern has improved, at least transiently, in the majority of patients studied (Nichols et al, 2008). Aspirin (ASA) therapy is commonly utilized as the standard of care in patients with complex cardiac defects to reduce platelet-initiated thromboses, which might occlude critical shunts or conduits created by surgery.
The primary objective of this study was to describe our institution’s experience with the spectrum of CHD associated with AVWS and the occurrence of bleeding complications in patients with CHD and AVWS. In this study, 11 CHD patients who had laboratory evidence of AVWS with or without bleeding complications were identified. Their medical records were retrospectively reviewed to determine eligibility and to collect the following data: type of CHD, VWD/bleeding laboratory results, bleeding events and anti-platelet therapy. The platelet function analysis (PFA-100), red cell distribution width (RDW), and multimer assay results were collected. All multimer assays were performed by the blood center of Southeastern Wisconsin. When possible, comparisons before and after surgery were made. Statistical analyses were performed using simple comparison statistics (mean, standard deviation). Each individual served as his or her own control.The mean age at diagnosis of AVWS was 8 years (range 1–21 years).
The cohort included five males (45%) and six females (55%). The most common cardiac defect observed was ventricular septal defect (VSD). Other types of CHD identified included: aortic stenosis; hyperplastic left heart syndrome; and mitral valve prolapse (Table 1). An abnormal PFA-100 and a decrement in large VWF multimers occurred in all the patients. RDW was elevated in nine of the cohort. A total of 24 surgical procedures were performed on nine children, several of these surgeries were performed prior to the diagnosis of AVWS. The bleeding presentations are shown in Table 1. Seventeen bleeding episodes were documented in nine patients and included seven haemorrhagic cerebral vascular accidents (CVA). Seven of the children with bleeding complications were on ASA therapy. There were no reports of bleeding events in these patients after ASA was discontinued. Three children in this series of 11 had normalization of the VWF multimers after corrective surgery, however the RDW remained abnormal.
Patient Demographic data 1NonePDA/AVSYesNo13·7 2Intracranial haemorrhage***HRHSYesYes14·5^ 3Post-operative bleedingTOFYesYes16·6^ 4Melena***TOF/VSDYesYes19·2^ 5Epistaxis. Excessive bleeding intraoperativelyTAYesYes15·2^ 6Haemorrhagic CNS infarction****TA/VSDYesYes12·7 7NoneHLHS/VSDYesYes17·2^ 8Bleeding from knee AVM following traumaVSDNoNo16·1^ 9Post-operative bleedingTOF/VSDYesYes16^10Post-operative bleedingTGA/VSD/PDAYesNo14·5^11Post-operative bleedingMVDYesYes15·7^Our study identified VSD as the most common cardiac defect. Bleeding events occurred in seven patients, four of whom were on ASA therapy. Given that AVWS confers an increased risk for bleeding symptoms, this risk may be further promoted in the presence of ASA therapy. ASA therapy is commonly utilized postoperatively in patients with complex cardiac defects and is designed to reduce the role of platelets in causing thromboses, which might occlude critical shunts or conduits created by the surgery to improve the child’s cardiac status.
In addition to thrombotic events, patients on ASA therapy postoperatively may have an increased risk for haemorrhagic strokes and other bleeding events. Additive postoperative ASA therapy in some patients with AVWS may overprotect for clotting and promote bleeding events. AVWS may, in fact, perform a physiological role in reducing the risk of thrombosis by crippling the action of VWF multimers. After surgical correction of the cardiac defect the multimer pattern improved, at least transiently, in some of the patients studied. We also observed an increased diversity of RDW relative to the normal range in the complete blood counts of patients with AVWS. This may be an effect of the so-called Waring-Blender Syndrome in which red cells have been injured due to excessive turbulent flow, resulting in a low-grade mechanical haemolytic anaemia. The Waring-Blender Syndrome has been observed in aortic stenosis and prosthetic heart valves when blood is accelerated with great velocity through a narrow opening with rigid walls (Ismeno et al, 1999;