chapter 4: hemodynamics Flashcards
edema vs effusion
edema = exudation of transudate or exudate into the interstitial space
effusion = fluid accumulation into potential spaces (body cavities) such as pleural space, peritoneal space (ascites), pericardial space, joint space
plasma transfusion, platelet transfusion, and red blood cell transfusion have are best to treat what defects
plasma
- factor deficiencys
- hypovolemic shock
- promotes coagulation and replenish plasma loss seen in shock from massive loss from burns or hemorrhage
platelet
- platelet dysfunctions (Bernard soulier syndrome)
- low platelet count (thrombocytopenia)
- treat overactive bleeding in these conditions
RBC
- anemia
- replenish after trauma, or surgery
describe the steps of primary hemostasis
*platelet adhesion/ activation/ aggregation = platelet plug
- platelet adhesion to sub endothelial surface by vWF and Gp1b interaction
- platelet activation = shape change to increase surface area, change to negative charge, conformational change of Gp2b-Gp3a complex, and platelet granule secretion of ADP and TXA2 by thrombin and ADP stimulation
- platelet aggregation is initiated by increased TXA2, thrombin conversion of fibrinogen to fibrin, Gp2b–Gp3a complex change to allow bivalent binding of fibrinogen and subsequent cross linking,
list the defects of primary hemostasis (platelet plug defects)
- vWF disease (vWF)
- Bernard Soulier syndrome (Gp1b)
- Glanzman thrombasthenia (Gp2b-3a)
- thrombocytopenia (low platelet count)
dehydration is a _____state
hyper coagulable (i.e. thrombotic)
sickle cell anemia causes what to occur in blood flow
STASIS
what would result in unilateral edema and what are common causes of it?
lymphedema by lymphatic obstruction
- filariasis (Wuchereia helminth infection)
- tumor resection surgery can remove LNs and cause lymphedema (breast cancer patients)
- Differentials: infection, inflammation, trauma, tumor, surgery, malformations
white vs red infarction
white- seen in organs with single blood supply (ex: spleen, heart, kidneys), arterial occlusion, solid organ, platelet rich
red- seen in organs with dual blood supply ( ex: lung), seen with venous occlusion, seen in loose tissue for blood collection, or because repurfusion injury, or because STASIS.
*extensive bleeding can cause brown -hemosiderin residue
defects of primary hemostasis vs secondary, vs small vessel defect manifestations
primary
- petechiae, purpura, mucocutanous bleeding, mentorhaggia, thrombocytopenia
- intercerebral hemorrhage
secondary
-hemearthrosis, bleeding into soft tissue or joints, by factor deficiciencys
small vessels
-ecchymosis, and hematoma
define air embolism and give details
-introduction of air bubbles into circulation causing ischemic injury
-causes:
cardiac catheterization / laparoscopic procedures
deep sea diving
**deep sea diving = decompression illness
Cause: increase in N2 in circulation as increase in pressure during descent; rapid ascent = N2 loss and introduction of air emboli
-bends: joint pain from bubble in muscles and around joints
-chokes: bubbles in lung vasculature cause edema, hemorrhage, and emphysema leading to respiratory distress
- if chronic it will form Caisson disease (decompression sickness)
- bone infarction due to multifocal ischemic necrosis of bone
- usually femoral head, tibia, humorus
DIC affects which PT or aPTT?
both will be abnormal
mechanism, presentation, and complication of the hyper coagulable state by oral contraceptive use
mechanism : increase estrogen levels by the pill causes increased liver production of coagulation factors and decreased anticoagulant factors
complication: increases risk of thrombosis
presentation: stroke / emboli
define amniotic fluid embolism and give details
- amniotic fluid enters mom circulation following delivery and causes allergic reaction
- Sx: sudden dyspnea, cyanosis, neuro change, shock, DIC
- can be lethal but if survives pulmonary edema develops
- **AF causes coagulation
- autopsy findings: squamous cells keratin, fat, mucin, inside moms blood vessels
PT vs aPTT time ? what do you use to assess primary hemostatic defect?
PT time reflects the extrinsic pathway
aPTT time reflects the intrinsic pathway
- flow cytomtery
- PFA-100 (platelet function assessment for adhesion and aggregation)
manifestations of acute and severe hemorrhage, and chronic blood loss
acute
-asymptomatic
severe
- hypovolemic shock
- increased intracranial pressure (brainstem herniation)
chronic
-iron deficiency anemia
(peptic ulcers, menstrual bleeding)
causes of decreased plasma oncontic pressure
hypoproteinemia by
- malnutrition (kwashiorkor)
- decreased albumin/ protein synthesis (liver failure)
- too much lost (kidney disease/ nephrotic syndrome)
definition of shock; and list the types
low cardiac output or low blood volume leads to decreased oxygen perfusion to tissues
- tissue O2 and nutrient delivery is inadequate to meet the physiologic needs of the body leading to hypoxic injury
- acute = reversible; prolonged = irreversible tissue damage
3 major mechanisms: decreased cardiac ouput, decreased blood volume (hypovolemia), or systemic inflammatory response syndrome causing increased need
types: cardiogenic, hypovolemic, shock associated with systemic inflammation, neurogenic, anaphylactic
origin / pathogenesis of septic shock
- *usually by gram + bacteria
- microbial pathogen recognition and subsequent release of TNF and IL-1 with increase in permeability and vasodilation (decreased vascular resistance and hypovolemia) and endothelial damage/activation (edema, NO release, hypovolemia) and coagulation (increased factor 7, TF, decreased protein C and antithrombin, stasis , and decreased coag factor washout) leading to to multiorgan dysfunction
- hypovolemic shock (hypotension from low BV)
- intravascular coagulation (DIC) [leads to hemorrhage]
- metabolic changes from decreased tissue oxygenation [ decreased ox phos , ATP, causing tissue necrosis and more inflammation, increased lactic acid and decreased pH]
multiorgan disfunction caused by: hypovolemia, hypotension, thrombosis, and subsequent decrease in O2 delivery leading to hypoxic injury
what is factor 2
prothrombin
what is the consequences of pulmonary edema? and clinical presentation associated with its manifestation ?
impedes O2 diffusion/ gas exchange
increases risk of bacterial infection
leads to pulmonary effusion
-seen in left ventricular heart failure
hyperemia vs congestion
hyperemia = too much blood arriving at arteriole end; physiologic and can be controlled by precapillary sphincter
congestion = venous obstruction causing decreased fluid drainage from venule side; pathologic
function of ADP
“platelet recruiter”
-increases activation of platelets by stimulating granule secretion
contributing factors to infarction ? types of infarction ? and what is seen on slide of infected tissue?
- anatomy of vascular supply (single or double or multiple)
- rate of occlusion (faster increases chance of infarction)
- tissue vulnerability to hypoxia
- types: MI, cerebral, pulmonary, bowel, gangrenous necrosis of limbs
- seen wedges shaped hypoxic injury (except brain) followed by acute inflammation
what is the risk of chronic emboli reorganized overtime
increased risk of pulmonary HTN
function of prostacyclin
inhibit platelet aggregation (vs TX A2)
vasodilation
what is the consequences of brain edema?
-can herniate through foramen magnum and compress brainstem blood supply = cause medullary neurologic damage or death
cholesterol cleft in embolus means the source is _____
atherosclerotic plaque
mechanism and clinical examples of of shock type: neurogenic and anaphylactic
neurogenic: anesthetic accident or spinal cord injury causing vasodilation and decreased vascular resistance due to autonomic disruption
anaphylactic : IgE mediated hypersensitivity run causing decreased vascular resistance
*both lead to hypotension and hypo-perfusion
mechanism, presentation, and complication of the hyper coagulable state by protein C and S deficiency and antithrombin 3 deficiency
mechanism: deficiency of protein C and S mean can not induce stopping of coagulation therefore inability to stop bleeding
complication: increased risk of venous thrombi, and recurrent ones
presentation: rare, begins in childhood
define systemic thromboembolism
- thromboembolus = varying level of blood vessel obstruction due to dislodges thrombi that become an emboli
- arterial/venous thrombi usually from cardia (mural) thrombi of left ventricle or vegetation from endocarditis or paradoxical embolism from PFO
- usually travel to LE to brain (or other organs) causing obstruction of blood supply and infarction
2 way renal failure causes transudate edema
- sodium/water retention by RAAS activation (increases hydrostatic pressure)
- nephrotic syndrome causes excess protein loss in urine decreased oncotic pressure)
effects of adrenal insufficiency in septic shock
initial increase in glucorticoids is stopped due to DIC causing hypoxic adrenal injury from low blood perfusion
define septic emboli and give details
-bloodborne infective material that can lead to septic infarction and abscess formation causing increase in inflammatory response
-seen in bacterial endocarditis vegetations break off
sx:
skin microemboli - purpuric
nail bed vascular damage - splinter hemorrhage
retinal microemboli- roth spots
signs of DVT? and what are outcomes of DVTs?
sx: unilateral swelling, warmth, redness, pain
outcomes: can lead to PE that
1. small = asymptomatic
2. medium = lodge in artery supply to portion of lung and cause SOB, dyspnea
3. large saddle emboli= lodge in primary arteriole trunk where bifurcation of pulmonary arteries is causing instant death from right heart failure
affects immediately following coumadin (anti-coal) delivery
- increased of coagulation and risk of thrombosis because decreases levels of protein C and S first
- can lead to coumadin induced skin necrosis
- therefore start with another anti-coagulant initially
what hemodynamic changes cause exudate vs transudate
exudate ( high in proteins and WBC and RBCs)
-caused by increased vascular permeability (seen in inflammation) and STASIS blood flow with some increase in interendothelial spaces
transudate (low cellular content)
- increased hydrostatic pressure or decreased oncotic pressure
- heart failure, liver disease, kidney disease
define hypercoagulabiltiy and list primary vs secondary causes
- aka thombrophilia
- disorders of the blood predisposing coagulation and increases risk of thrombis
- *venous thrombi is most common
primary (genetic) *point mutations
- decreased antithrombotic factors
- increased prothromboitic factors (factor 5 disease, prothrombin mutation)
secondary (acquired) *multifactorial
- bed rest (immobility)
- MI
- A-fib
- cancer
- tissue injury from surgery
- proestetic valves
- DIC
- heparin induced thrombocytopenia
- Oral contraceptives
5 functions of thrombin
- fibrinogen converter to fibrin (creation of secondary hemostatic plug and fibrin stabilization)
- PAR cleavage and continued platelet activation/ aggregation by stimulating platelet granule release (Increases TXA2/ ADP for recruitment and aggregation)
- pro inflammatory ( works with histamine to induce release of P-selectins from WP bodies to induce rolling)
- anti-thombotic (binds with thrombomodulin to activate plasmin)
- promoting irreversible platelet contraction (platelet plug stabilizer )
main effected organs in cardiogenic and hypovolemic and septic shock
- brain, heart , lungs, kidneys, adrenals, GI tract
- mimic hypoxic injury
adrenals
-coritcal lipid depletion used for steroid use
kidneys
-acute tubular necrosis
lungs
-not affected in pure hypovolemic shock bc resistant to hypoxic injury, but in septic shock = diffuse alveolar damage
DIC from septic shock causes micro thrombi deposition affected these organs. and lead to petechial hemorrhages on serosal skin
what are heart failure cells
hemosideren laden macrophages seen in hemosiderosis
mechanism of edema by decreased oncontic pressure pressure
loss of fluid equilibrium and osmosis across semi-permeable membrane
what is common in patients under the age of 50 with a stroke
patent foramen ovale causing venous emboli to become arterial and enter cerebral vasculature
what can cause increased capillary hydrostatic pressure and subsequent edema
- increased blood flow (hyperemia)
- venous obstruction (congestion)
- increased salt/water retention (RAAS activation)
- increase blood volume
clinically:
-heart failure
-renal failure
-pregancy
-liver cirrhosis