Blood pathophysiology
Terms
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- anemia
-
1) decrease in the total # of circulating RBC or
2) decrease in the quality of Hb or
3) decrease in the amount of Hb
3) decrease in the - anemia usually result from?
-
1) < production of RBC
2) blood loss
3) > destruction of RBC
4) a combination of the previous ones - anemias can be classified according to their?
-
1) etiology (cause)
2) morphology (shape and intrinsic chara.) - morphologic class refers to?
-
1) cell's size
2) Hb content - for the cellular size
-
"cytic"
1) normosytic
2) macrocytic
3) microcytic - for the Hb content
-
"chromic"
1) normochromic
2) hyperchromic
3) hypochromic - What is anysocytosis?
- there're RBC with "different sizes" in the same pt
- What is poikilocytosis?
- there're RBC with different SHAPES in the same pt
- clinical manifestations of anemia will depend basically of the pt's ability to compensate the?
- hypoxemia r/f a reduced Hb content
- compensation mainly involves?
-
1) CV
2) resp.
3) hematological system - in cases of hemorrhagic anemias?
-
1) < blood volume
2) > reabsorption of fluid from extravasc.comp.
3) > volume but viscocity is decrease
4) circ. is faster and more turbulent - hemorrhagic anemia : CV
-
1) dilated heart demands stronger contractions
2) tachycardia
3) CHF - tissue hypoxia from hemorrhagic anemia cause?
-
1) > CO
2) > RR
3) > depth of breathing
4) > Hb-O2 dissociation at the tissue level - severe or sudden onset in anemias cause?
- peripheral vasoconstriction to redirect blood flow to vital organs
- kideneys react to < blood flow by triggering?
-
renin-angiotensin mech.
1) > retention of Na and water
2) < urine output - hemolysis cause?
- icterus due to accumulation of production from broken RBC
- anemia caused by Vit. B 12 deficiency affect?
-
nervous system
- cause myelin degeneration in the SC and peripheral nerves - S&S of Vit. B 12 deficiency anemia?
-
1) paresthesias
2) extreme weakness
3) gait disturbances
4) spasticity
5) reflex abnormalities
6) abd. pain
7) N/V
8) anorexia
9) low-grade fever - macrocytic-normochromic anemias
- = megaloblastic anemias
- megaloblastic anemias result from?
-
deffective DNA synthesis
- leading to abnormal erythropoiesis - abnormal erythropoiesis produces?
-
megatoblasts (very large stem cells)
- which mature into macrocytes (large RBC) - megaloblastic anemias (macrocytic-normochromic anemias) usually caused by deficiency of?
- Vit. B 12 or Folate
- pernicious anemia caused by defeciency of?
- Vit. B 12 due to lack of the intrinsic factor (IF) in the gastric mucosa
- lack of the IF in the gastric mucosa due to?
-
1) congenital
2) atrophy of the gastric mucosa
3) after partial or total gastrectomy - chronic atrophic gastritis usually precipitated by?
-
1) heavy alcohol ingestion
2) hot tea ingestion
3) smoking - pt with pernicious anemia is at risk for developing?
- gastic cancer
- S&S of pernicious anemia: Hb > 8
-
1) vascular symptoms
2) infections
3) mood swings
4) renal, CV, GI problems - S&S of pernicious anemia: Hb 7-8 g/dl
-
1) weakness
2) fatigue
3) distal paresthesia
4) neuro. manifestations
5) ataxia
6) spasticity
7) loss of the vibration and position sense
8) anorexia
9) abd. pain
10) wt. loss
11) sore tongue
12) hepato-splenomegaly - neuro. manifestations (ataxia, spasticity, loss of the vibration and position sense) are due to?
- demyelinization of the lateral and post. columns of the SC
- diagnosis of pernicious anemia is established by?
-
1) clinical manifestations
2) blood tests
3) bone marrow aspiration
4) Schilling test - Schilling test
- If there is a problem with the stomach's ability to make intrinsic factor, Stage I of the test will be abnormal and Stage II will be normal. Both the Stage I and II Schilling tests will be abnormal in patients who have problems absorbing Vitamin B-12 and intrinsic factor in the small intestine.
- if low absorption of cobalamine (increase in urinary excretion)
- pernicious anemia
- pernicious anemia is fatal without Tx usually in?
-
1-3 years
but with the proper tx (adm of parenteral Vit. B12) death is very rare - folate deficiency anemia
- 1) lack of folic acid
- folic acid is essential to?
-
1) erythropoiesis
2) a component of thyamine, adenine, and guanine
3) indispensable in DNA synthesis - daily requiremenet of folic acid?
- 50-200 mcg from the diet
- folate deficiency is increased in?
-
1) alcoholic persons
2) chronically malnurished individuals
3) people who maintain diet low in vegetables - clinical manifestations of folate def. anemias
-
1) similar to pernicious anemia
2) plus severe stomatitis
3) painful ulcerations of the buccal mucosa and tongue
4) dysphagia
5) flatulence
6) liquid diarrhea - neurological manifestations of folate def. anemias?
- not typically present
- Tx for folate def. anemia
-
1) daily adm. of oral folate (1mg normally, 5mg for alcoholics)
2) clinical manifestations usually disappear in 1-2 wks - microcytic-hypochromic anemias
-
1) disorders of Fe2+ metabolism
2) disorders of porphyrin and heme synth.
3) disorders of globin synth. - iron deficiency anemia
- most common type of anemia worldwide
- cause of iron def. anemia in developing country
-
1) r/f parasitic infestations (hookworm)
2) < ingestion of iron due to malnutrition - cause of iron def. anemia in well-developed societies?
-
1) pregnancy
2) chronic blood loss (gastric or duodenal ulcers and cancer, ulcerative colitis and menorrhagia) - blood loss of --ml/day (1-2mg of iron) is sufficient to cause anemia
- 2-4 ml
- iron def. anemia develops when?
-
1) < ingestion or > loss of iron alter the balance in its met.
2) when iron demand is greater than its supply - stage 1 of iron def. anemia
-
1) body Fe storages are depleted
2) erythropoiesis and Hb content in RBC remain normal - stage 2 of iron def. anemia
-
1) not enough Fe available
2) Fe-def. erythropoiesis begins - stage 3 iron def. anemia
- 1) small, Hb-def. cells enter the circulation replacing the old normal RBC removed from blood
- clinical manifestations of iron def. anemia have a?
- gradual onset and usually are well-tolearted till Hb drops to +/- 7-8g/dl
- S&S of iron def. anemia
-
1) fatigue
2) weakness
3) dyspnea
4) pale skin and mucose memb.
5) thin, brittle and spoon-shaped or concave (Koilonychia) nails
6) glossitis
7) gastritis
8) HA
9) irritability
10) neuromuscular changes - evaluation for iron def. anemia is based on?
-
1) clinical manifestations
2) lab tests which measure the Fe stores directly or indirectly - direct Fe measurement
- bone marrow biopsy
- indirect Fe measurement
-
1) serum Ferritin
2) transferrin saturation
3) total iron-binding capacity - Tx for iron def. anemia
-
1) find and elinimate all sources for blood loss
2) Fe adm. - What is the most conclusive diagnosis for iron def. anemia?
- an increase in Hb of 1-2 g/dl after initiation of Fe therapy
- normocytic-normochromic anemias
-
1) less common than the other types
2) do not share any common cause - normocytic-normochromic anemias include?
-
1) aplastic anemia
2) posthemorrhage anemia
3) hemolytic anemia
4) anemia of chronic inflammation
5) sickle cell anemia - aplastic anemia results from?
-
1) bone marrow hypoplasia
2) bone marrow aplasia
- a condition where erythrocyte stem cells are underdeveloped, defective, or absent - bone marrow hypoplasia or aplasia may lead to?
- pancytopenia - all the series are affected (< RBC, WBC, Plt)
- 1) hereditary aplastic anemia
- Fanconi anemia (defect in DNA repair)
- 2) acquired aplastic anemia
-
1) primary - idiopathic, +/- 50 % of cases with 80 % over 50 yr of age
2) secondary - caused by variety of chemical agents and ionizing radiat - pure red cell aplasia (PRCA)
-
1) is very rare
2) affects the red series only - palliative Tx for aplastic anemia?
-
1) blood transfusions
2) bone marro transplant
3) pharmacologic stimulation of the marrow function
4) splenectomy - hereditary spherocytosis is also known as?
-
1) congenital nemolytic anemia or
2) acholuric jaundice
** most common type of hemolutic anemia with normal Hb - hereditary spherocytosis is caused by?
-
1) unknown abnormality of protein in the RBC memb.
2) which > permiability to Na
3) leads to > ATP consumption to maintain the Na-K pump working
4) cause > early aging and destruction of RBC
5) also cause abnormal RBC shape - What is spherocyte?
- abnormal RBC shape
- circulation of spherocytes through the spleen resulting in?
-
1) sequestration
2) destruction - clnical manifestations of hereditary spherocytosis?
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1) anemia and hyperbilirubinemia (neonatal, early infancy)
2) splenomegaly (after infancy)
3) gallstones (early as 4-5 yrs) - What is the most serious complication during childhood for spherocytosis pts?
- aplastic crisis
- evaluations for hereditary spherocytosis include?
-
1) family hx
2) blood smear
3) studies of osmotic fragility
4) studies of autohemolysis (**there's NO specific test) - splenectomy for pts with spherocytosis produces?
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CLINICAL cure
(should be performed after 5yrs of age) - sickle cell anemia
- chara. by the presence of Hb S r/f a mutation
- mutation of sickle cell anemia replaces ----- by -----
- replaces the Glutamic acid by Valine
- Hb S reacts to deoxygenation and dehydration by?
-
solidifying and stretching the RBC into elongated crescents which are stiff and can't change shapes as the normal RBC when passing through the microcirculation r/i a tendency to occlude the blood vessels
(cause ischemia, pain and infarction) - sickle cells undergo?
-
1) hemolysis or sequestration in the spleen
2) blood pooling and infarction of splenic vessels
3) > erythropoiesis in the marrow and sometimes the liver - clinical manifestations of sickle cell anemia?
-
1) common to all hemolytic anemia
2) pallor
3) jaundice
4) ** icterus
5) fatigue
6) irritability
7) crisis - vasoocclusive (thrombotic) crisis
-
may be spontaneous or precipitated by
1) infections
2) exposure to cold
3) < PO2
4) < pH
5) localized hypoxemia - aplastic crisis
- r/f RBC with a shorter survival (10-20 days) and a compromised compensatory response
- sequestration crisis
- in both the spleen and liver
- hyperhemolytic crisis
- is unusual but may occur in a/w certain drugs and infections
- What is the most common cause of death in pt with sickle cell anemia?
- infection (meningitis and general sepsis)
- evaluation for sickle cell anemia?
-
1) parent's hematologic hx
2) analysis of clinical manifestations
3) hemat. test are indispensable - sickle cell solubility test
- when sickle cell solubility test confirmes the presence of Hg S in peripheral blood, Hb electrophoresis informes its amt. in the RBC
- prenatal dx of sickle cell anemia can be made with?
-
1) chorionic villus sample (8-10 wks gestation)
2) amniocentesis (15 wks gestation) - Tx for sickle cell anemia
-
1) prevent consequences of the anemia
2) prevent crisis (avoid fever, infe., dehydration, acidosis, exposure to cold)
3) bone marrow transplantation
4) blood transfusion
5) oral adm. of folate
6) splenectomy
7) genetic counseling