Lecture 16 Flashcards
Hemorrhage by rhexis
(rapid)
substantial tear in blood vessel or heart chamber
Hemorrhage by diapediesis
escape of RBC one by one through minute or microscopic defects in the vessel wall
hemothorax
hemorrhage into the pleural cavity
hemopericardium
into the pericardial sac
hemoperitoneum
into the peritoneal/ abdominal cavity
hemarthrosis
into synovial joint
hematuria
blood in the urine
hemoptysis
coughing of blood
hematemesis
vomiting of blood
hematochezia
passage of fresh blood in the feces
dysentery
diarrhea containing blood
melaena
diffuse, dark red black discoloration of feces due to upper GIT hemorrhage or swallowing of blood from the resp tract
epistaxis
bleeding from the nose
hyphema
hemorrhage into anterior chamber of the eye
petechiae
tiny pinpoint foci of hemorrhage
typically on skin and on mucosal and serosal surfaces
purpura
slightly larger than petechiae>3mm
ecchymoses
larger foci of hemorrhage 2-3 cm blotchy and of irregular shape
Paintbrush
linear or streaky hemorrhages especially over serosal or mucosal membranes
hematoma
palpable, space occupying mass of clotted blood within the tissues
How do hematomas resolve?
Color pigments
phagocytosed then filled with scar tissue
acute- red blue poorly O2 hemoglobin
subacute- blue green biliverdin and bilirubin
chronic-gold brown yellow hemosiderin
What factors determine the clinical significance of hemorrhage
location, rate, and volume of blood loss
What is MOST COMMON cause of hemorrhage
physical trauma
What are other potential causes of hemorrhage than trauma(3)
severe tissue inflammation
spontaneous rupture
ecto/endo parasites
Hemorrhagic diatheses
clinical disorders of hemostasis characterized by a bleeding tendency
Clinical signs of a defect in primary hemostasis(6)
bleeding immediately after venipuncture small volume bleeds bleeding from multiple sites petechiae and ecchymoses hematomas uncommon bleeding from mucosal membranes into skin and over serosal surfaces
Clinical signs of defect in secondary hemostasis(6)
delayed bleeding after venipuncture large volume bleeds often localized to one site petechiae and ecchymoses rare hematomas common bleeding into muscles, joints, and or body cavities
4 major mechanisms for defect in primary hemostasis
thromobocytopenia
thrombocytopathies (thrombopathies)
vW disease
damage to small blood vessels
Major mechanisms responsible for thrombocytopenia in domestic animals(5)
dec platelet production (cats) platelet destruction (dogs) consumption (utilization) of platelets (DIC) platelet sequestration (spleen or liver) massive acute hemorrhage
why is decreased platelet production the most common mechanism for thrombocytopenia in cats
largely due to retroviral infection (FLV) or myeloproliferative disease
Why is platelet destruction the most common mechanism for thrombocytopenia in dogs
often immune mediated
or secondary to another disease process (neoplasia, viral, bacterial…)
Thrombocytopathy (thrombopathy)
causes of it(3)
platelet function disorders,
drugs( COX blockers) (aspirin, NSAID) inherited, diseases (lupus)
Role vWF plays in primary hemostasis
mediates the adhesion of platelets to exposed subendothelial collagen via their outer surface GpIb receptors
Which species is most commonly affected by vWD? Breed? how is it inherited in this breed
dogs
doberman pinscher
autosomal recessive inheritance
Clinical signs in a dog with vWD
3 types
subclinical or mild to moderate bleeding (type 1- doberman)(most common) severe hemorrhage (type 2) scottish terriers , severe hemorrhage( type 3)
Blood vessel disorders that can manifest as petechiae and ecchymoses in skin and or mucous membranes(3)
toxemia
bacteremia
vitamin deficiency(scurvy)
