Thursday, September 23, 2010

Types of Hemorrhage...1

Ecchymoses - Larger i.e 1- to 2-cm or more subcutaneous hematomas (bruises)

Associated with increased severity of above disorders


Types of Hemorrhage...2

Purpuras - Slightly larger i.e 3- to 5-mm hemorrhages are called purpuras.

Associated with
–Disorders of petechiae plus
–vascular inflammation (vasculitis)
–increased vascular fragility
–Trauma.

Types of Hemorrhage...3

Petechie - Minute (1- to 2-mm) hemorrhages into skin, mucous membranes, or serosal surfaces

Associated with thrombocytopenia or thrombasthenia

Types of Hemorrhage...4

Hematoma – accumulation of blood within the tissue

May be relatively insignificant as in a bruise or may be life threatening e.g., a massive retroperitoneal hematoma resulting from rupture of a dissecting aortic aneurysm.


HEMORRHAGE

Extravasation of blood through a ruptured blood vessel wall
Causes-
trauma

Vascular wall disturbances like
–Hypoxia, infections, drug, toxins

Other hemorrhagic diatheses
–Thrombocytopenia (low platelet count)
–Thrombasthenia (defective platelet function):
–Abnormalities in clotting factors.

Tuesday, September 14, 2010

What is left shift?


A left shift is an increase in the number of immmature neutrophils or polymorphonuclear leukocytes (PMN's). These are called band or stab neutrophils, and in more severe cases there may be metamyelocytes or myelocytes present. Mature (normal) neutrophils are referred to as segmented neutrophils or segs. In a normal differential there should be 0-6 bands per 100 WBC's and no metamyelocytes or myelocytes.

These immature cells make it into the bloodstream because chemical signals (cytokines, complement, etc.) released from the site of inflammation stimulate the bone marrow to release them prematurely. They continue to mature after entering the bloodstream, and the left shift will usually disappear within a few days if the cause of the inflammation is addressed.

An increased neutrophil count with a left shift is typically associated with bacterial infection, and may be increased in other inflammatory conditions or post-surgically.

What is LR?


A leukemoid reaction (LR) is a hematological disorder, defined by a leukocyte count greater than 50,000 cells/mcL with reactive causes outside the bone marrow

LR is characterized by a significant increase in mature neutrophils in the peripheral blood and a differential count showing left shift.
The diagnosis of LR is based on the exclusion of chronic myelogenous leukemia (CML) and chronic neutrophilic leukemia (CNL).

Monday, September 13, 2010

Causes of leukocytosis. (a)

Neutrophilic leukocytosis
Acute bacterial infections, especially those caused by pyogenic organisms;
sterile inflammation caused by, for example, tissue necrosis (myocardial infarction, burns)

Eosinophilic leukocytosis(eosinophilia)

Allergic disorders such as asthma, hay fever
allergic skin diseases (e.g., pemphigus, dermatitis herpetiformis)
parasitic infestations;
drug reactions;
certain malignancies (e.g., Hodgkin disease and some non-Hodgkin lymphomas);
collagen vascular disorders and some vasculitides;

Causes of leukocytosis. (b)

Basophilic leukocytosis(basophilia)

Rare, often indicative of a myeloproliferative disease (e.g., chronic myelogenous leukemia)

Monocytosis
Chronic infections (e.g., tuberculosis), bacterial endocarditis, rickettsiosis and malaria;
collagen vascular diseases (e.g., systemic lupus erythematosus)
inflammatory bowel diseases (e.g., ulcerative colitis)

Lymphocytosis
Accompanies monocytosis in many disorders associated with chronic immunologic stimulation (e.g., tuberculosis, brucellosis);
viral infections (e.g.,hepatitis A, cytomegalovirus, Epstein-Barr virus);
Bordetella pertussis infection.

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