Test 2 RBC, Hgb, Iron Metab, O2 Tx Flashcards
Blood is ____% of total body weight, divided into __________ (55%) and __________(45%).
8% of tbw
Plasma 55%
Formed elements 45%
Plasma is divided into:
Proteins _____%
Water ______%
Other solutes ___%
Proteins 7%
Water 91%
Other solutes 2%
Most abundant protein in plasma?
Albumin 58%
Other proteins in plasma besides albumin?
Globulins 38%
Fibrinogen 4%
3 things that make up formed elements in blood
Platelets
WBC
RBC
Formed elements mainly constitutes _______, normal value ~45%
Hgb
A cubic mm is the same as what?
Microliter
Transports oxygen via iron in hgb from alveoli of lungs to cells
RBC fxn
RBC transport _________ from cells to alveoli of lungs for exhalation
CO2
CO2 is partially dissolved in ________ of RBC’s and partially bound with ______
Cytoplasm
Hgb
RBC contain this enzyme that plays a role in CO2 transport and regulation of acid-base balance.
Carbonic anhydrase (CA)
Normally the formation of carbonic acid is very _______, CA makes the process 5 x’s faster
Slow
Formula involving CA and CO2 tx.
CO2+H2O
H2CO3
H+ + HCO3-
This serves as a very powerful acid-base buffer to regulate pH of body fluids
Hgb
How does hgb regulate pH of body fluids?
And AA in the globin portion of the hgb can bind with H+ ions; release or bind when pH indicates.
What 2 things does an anemic pts have a decreased ability to do?
Decreased ability to tx O2
Decreased ability to regulate acid-base balance
What drives the CA equation and the direction it takes?
Concentration of the reactants
2 reasons men have higher RBC count than women
Testosterone levels favor bone marrow production of RBC
Menses
Normal H/H levels
Hgb: 12-18 gm/dl
Hct: 38-52%
Each ______ of hgb can combine with and transport _______ mL of O2
Gram
1.34 mL of o2
Production of RBC’s during prenatal period
Liver, spleen, lymph nodes
Production of RBC from birth-about 5 years
Shifts to all bone marrow
After about 20 years production of RBC is primarily where?
Bone marrow of proximal humerus and tibia, vertebrae, sternum and ilium
Mainly ilium!!
When doing anesthetic for bone marrow extraction, it is important to give plenty _________
Narcotics
Very painful procedures
Common ancestor of formed elements of RBC’s
Stem cell (pleura-potential hematopoietic stem cell)
First cell identified as belonging to RBC lineage
Proerythroblast
Formation of RBC from proerythroblast to RBC
Proerythro Early erythroblast Intermediate erythroblast Late erythroblast Reticulocyte RBC
When is the nucleus extruded from the RBC
Between late erythroblast to reticulocyte
Blood cell can no longer replicate when?
When nucleus extruded
Rbc do not have mitochondria, how do they produce ATP?
Anerobic metabolism/glycolysis
Gross 4 ATP,. Net 2 ATP
Why do rbc not participate in oxidative metabolism
They would use the O2 up themselves and not give to the rest of the body
RBC do not have this, so they cannot produce enzymes
Endoplasmic reticulum
All the enzymes in RBC will be developed in the ___________ in earlier stages of development
Bone marrow
Point at which rbc moves from the bone marrow to the circulation
When becomes reticulocyte
This makes reticulocytes more predisposed to lysis than mature RBC
Larger size
Normal % of reticulocytes in the blood
1-3%
What could cause increased reticulocyte count?
Hemorrhage
Getting a reticulocyte count can be helpful in assessing treatment of anemia. TRUE/FALSE
TRUE
Shape of rbc
Biconcave disc; pliable
Principal factor that stimulates bone marrow RBC production
EPO
90% of EPO is produced by __________ cells of the kidneys
Peritubular epithelial cells
EPO is produced in response to __________ of the cells that secrete EPO
Hypoxia
These can cause hypoxia but are not what increases EPO secretion
RBC count
Hgb conc
Hct
EPO stimulates ________ and causes them to proceed through further stages of development more rapidly.
Proerythroblasts
EPO increases rate at which reticulocytes move from the _________ to _________
Bone marrow to circulating blood
With EPO secretion, there is initial increase in percentage of ________, then ________ will increase
Initial increase of reticulocyte
Then mature RBC count, H/H
As RBC’s increase and hypoxia decreased, ______________ will decrease amount of EPO secretion
Negative feedback
Maturation factors essential for RBC DNA synthesis and normal RBC maturation
Vit B12 (cobalamin) Folic acid (folate)
If you have insufficient Vit B12 and/or insufficient folic acid, you have RBC _________ failure and abnormally _______ RBC’s (_______ or ________)
Maturation failure
Abnormally large RBC
Megaloblasts or macrocytes
What types of anemia can you have with vit B12 deficiency?
Megaloblastic
Macrocytic
Pernicious
Both vit B12 and folate def anemias cause abnormal oxygen transport and easy hemolysis. TRUE/FALSE.
TRUE
Vit B12 extrinsic factor must bind with intrinsic factor, secreted by the ________ cells; vit B12 bound with intrinsic factor is absorbed from the ______
Secreted from gastric parietal cells
Absorbed from ileum
Causes of vit B12 def (5)
Inadequate dietary intake
Atrophy of gastric mucosa and inadequate intrinsic factor
Gastric bypass or gastric reduction operations
Small bowel resection, esp. of ileum
Malabsorption syndromes of small bowel
Who is at risk of inadequate dietary intake of B12
Vegetarians
Why des gastric bypass and gastric reduction sx’s put you at risk for vit b12 def
Decreases amount of intrinsic factor being secreted
What causes folic acid deficiency and anemia?
Usually inadequate dietary intake
A hgb molecule contains ___ AA chains, 2 _____ and 2_____ chains
4 AA chains
2 alpha
2 beta
AA chains are the _____ portion of hgb; each ends in a ______ with iron in the middle; this is where O2 binds.
Globin portion
Heme
Hgb combines with O2 at this level
Alveolar-capillary level
Hgb releases O2 at this level
Capillary-tissue level
The iron in hgb combines loosely and reversible with O2. TRUE/FALSE
TRUE
Iron in the non-oxidized form that is able to release O2 to cells
Fe++
FERROUS form
Oxidized form of iron that cannon release O2 to cells
Fe+++
Ferric form
Type of anemia when iron in the heme portion is oxidized in the ferric form
Methemoglobinemia
Each Fe++ can combine with ____ Oxygen molecule (O2)
One
Since a Hgb molecule contains 4 ____, each hgb molecule can combine with 4 _______ of O2 or _____ atoms of oxygen.
Molecule has 4 Fe++
Hgb molecule combines with 4 molecules of O2 or 8 atoms of O2
Drugs that cause MetHb
Prilocaine Lidocaine (large amount) Benzocaine (cetacaine) Nitroglycerine, sodium nitroprusside Phenytoin Sulfonamides
How does prilocaine cause MetHb?
Generates Ortho-toluidine which oxidizes hemoglobin
Lidocaine in large amounts can cause MetHb, how many mg?
~600 mg
When can nitroglycerine or sodium nitroprusside cause MetHb?
Prolonged administration or hepatic/renal failure
With MetHb, you will have low ______ in the setting of a normal _________.
Low SPO2
Normal arterial PO2
Measures O2 dissolved in the plasma portion of blood
PO2
Why will you have low SPO2 reading?
Oxyhemoglobin, will not pick up ferric form
Color of arterial blood with MetHb
Chocolate, dark-red, brownish to blue
Can have ______ urine with MetHb
Brown
How can we diagnose MetHb?
Direct measurement of MetHb by co-oximetry (normal <2-3%)
Clinical cyanosis in the presence of normal arterial PaO2
Pulse ox: sats will hover around 85% regardless of intervention
Asymptomatic with MetHb level
<20%
Discontinuation of the offending agent
No other therapy
Symptomatic or a MetHb level of >__%
Treatment??
> 20%
Methylene blue (first line treatment) 1-2 mg/kg IV over 5 min
Blood transfusion
Hyperbaric oxygen
Dose for methylene blue tx of MetHb
1-2mg/kg IV over 5 min
How does methylene blue treat metHb?
Reverses ferric form back to ferrous form of iron
Lab taken in adults that measures a component of hgb that will bind to glucose over time
HgbA1c
HgbA1c is indicative of avg blood glucose over about _______ weeks
6-8
Tissues where iron is store
Liver
Spleen
storage form of iron; easily released as free iron
Ferritin
When ferritin is saturated, iron is stored as this; very hard to convert back into free iron
Hemosiderin
Iron deposits seen in skin; can be from massive blood transfusions
Hemosiderosis
When iron is absorbed, binds with ____________, the transport form of iron; most readily available pool of iron to be used by bone marrow for EPO
Trasferrin
Protein synthesized in the liver; storage form of iron
Ferritin
Fe++ is easily absorbed by the small intestine. TRUE/FALSE.
FALSE.
Poorly absorbed
Fe++ is absorbed from the small intestine into the ______ first and stored as trasferrin; readily available for hgb and tissues.
Plasma
Fe is excreted ____mg daily, by ______ and ______.
0.6 mg daily
Menses and stool
How is free iron utilized in the tissues?
Stored as ferritin
Stored as hemosiderin
Heme
Enzymes
Phagocytose RBC, degrade hgb into bilirubin and free iron
Macrophages
Macrophages break down RBC into ______ portion and ________.
Heme
Globin
Further Broken down in to AA and returned to the AA pool of the body
Globin portion of hgb
______ can be released from the heme portion and be returned to the bone marrow to be incorporated into new RBC, or transferred to storage sites such as the ______ and ______.
Heme
Liver and spleen
The rest of the heme (besides iron) is converted to _______, then to bilirubin, then to free or ________ bilirubin and transferred to the liver.
Biliverdin
Unconjugated
Free bilirubin is _______ by the liver and released into the _____ and transported through the GI tract and excreted.
Conjugated
Bile
Some bilirubin will be absorbed from the intestines into the blood and excreted by the kidneys; this is what gives color to what two things excreted from the body?
Brown to poop
Yellow to pee
What is important to know if bilirubin level is elevated?
Whether it is conjugated or unconjugated
Elevated Free bilirubin could be caused by what?
Anemias where RBC are hemolyzing faster than liver can conjugate it (most common)
Very diseased liver
Obstruction to the bile duct or any other obstruction in the liver will cause elevated ________ bilirubin levels
Conjugated
~_____% of oxygen is dissolved in the plasma of arterial blood (ABG)
~2-3%
Component from which PaO2 is measure for arterial blood gases
~2-3% of O2 dissolved in the plasma of the arterial blood
ABG measurement of O2 may or may not represent amount of oxygen transported to cells and released to cells. TRUE/FALSE
TRUE
~______% of O2 combines with Fe++ on hgb in RBC’s
97-98%
Decreased RBC count and decreased hgb will decrease oxygen ______
Transport
PO2 on venous end of pulmonary capillary is ____; PO2 in alveolus is _____
Venous 40
Alveolus 104
Based on partial pressure gradient O2 will move how at the venous end of pulmonary capillary?
O2 will move from alveoli to pulmonary capillary
PCO2 at pulmonary capillary and alveolus at venous end of capillary
Alveolar PcO2 40
Capillary PCO2 45
Arterial side of pulmonary capillary; what are the PO2 levels and PCO2 levels for the blood and the alveolus?
Alveolus
Po2: 104
PCO2: 40
Blood
Po2: 104
PCO2: 40
As blood approaches left side of heart PO2 drops from 104 to ____. Why?
95
Bronchial circulation
When blood reaches left atrium Po2 will probably decrease even further, why?
Thebesian veins
At the tissue capillary what are the PO2 and PCO2 levels at the arterial side of the blood, tissue and interstitium?
Blood:
PO2: 95
PCO2: 40
Interstitium
Po2: 40
PCO2: 45
Tissue:
Po2: 20
PCO2: 46
PO2 and pco2 levels at venous side of tissue capillary of the blood and interstitium
Blood:
Po2: 40
PCO2: 45
Interstitium:
Po2: 40
PCO2: 45
Depicts relationship between Po2 and saturation of hemoglobin with o2 of affinity of hgb for o2
Oxyhemoglobin dissociation curve
HIGH/LOW po2: affinity of hgb for O2 is high; e.g., pulmonary capillaries
High po2
HIGH/LOW PO2: affinity of hgb for o2 is low; e.g., tissue capillaries
Low po2
What PO2 is when O2 sat is 50%; about _____ mmhg
P50
~27mmHg
If P50 is <27, what shift do you have in the curve?
Left shift
Is P50 is >27, what type of shift is present?
Right shift
Po2 in the tissue at rest is about __ mmHg; oxygen released to the tissues at rest is about ___%
40mmHg
23%
Oxyhgb dissociation curve during exercise; % of O2 released to tissues?
73%
25% remains in the blood
Shift of oxyhgb curve to the right = ________ affinity of hgb for O2; for a given Po2, % O2 sat is LESS/MORE than expected.
Decreased
Less than expected
Changes in pH, CO2, temp, and 2,3 DPG with righward shift?
Decreased pH
Increased CO2
Increased temperature
Increased 2,3 DPG
Oxyhgb curve shift up and to the left = ________ affinity of hgb for O2; for a given PO2, %O2 sat is HIGHER/LOWER than expected
Increased affinity
Higher than expected
Changed in pH, CO2, temp and 2,3 DPG associated with leftward shift
Increased pH
Decreased CO2
Decreased temp
Decreased 2,3 DPG
How do opioid shift he oxyhgb curve and why?
Rightward shift
Hypoventilation and increased CO2, decreased affinity of O2 for hgb
Normal physiologic shifting of oxyhgb dissociation curve; how CO2 affects transport of O2.
Bohr effect
Bohr effect at alveolar-capillary interface
CO2 diffuses out of the capillary
blood becomes more alkaline
3% shift to the left
Favors O2 affinity for hemoglobin
Bohr effect at the capillary-cell interface
CO2 diffuses into the blood
Blood becomes more acidic
3% shift to the right
Favors O2 release to cells
How O2 affects transport of CO2
Haldane effect
Haldane effect at alveolar capillary interface
O2 diffuses into the blood (RBC)
Displaces CO2 from hgb
CO2 can be exhaled from lungs
Haldane effect at capillary- cellular interface
O2 diffuses into cells
Frees up hgb for CO2 binging
Allows for CO2 transport
At capillary-tissue interphase; release of CO2 from cells into blood; phase ____ of CO2 tx.
Phase 1 of CO2 transport
At alveolar-capillary interphase, release of CO2 from the blood into the alveoli to be expelled; phase ____ of CO2 transport
Phase 2
Body cells generate CO2 from ______
Metabolism
CO2 is transported from cells, across capillary wall and into capillary; 5% dissolves in ______ as free CO2, and 95% enters ______
Plasma
RBC
Of the 95% of CO2 that enters the rbc, what happens after in the cell first?
Small amount of CO2 dissolves in intracellular water
30% of CO2 bings with hgb to produce carbamino hgb
65% reacts with water to form carbonic acid
After CO2 reacts with water to form carbonic acid, carbonic acid dissociated to form ______ and _______
Bicarbonate (hco3-)
Hydrogen ions
What happens to the H+ ions after carbonic acid dissociates in the rbc?
Immediately buffered and carried by globin portion of hgb
When carbonic acid dissociates in the rbc, the bicarb conc increases; some diffuses into _______, and _______diffuses from plasma into the rbc; what is this called?
Plasma
Chloride
(Phase 1) Chloride shift or “Hamburger shift”
What is the purpose of the hamburger shift?
Anion for anion to maintain electric neutrality
During phase 2 of CO2 transport, what happens to the 5% of free CO2 in the plasma?
Diffuses into alveoli and is exhaled
In phase 2 of CO2 tx, CO2 is released from _____ as oxygen diffuses into the RBC
Hgb
After CO2 is released from rbc in phase 2 of CO2 tx, it diffuses into the _______ to be exhaled; this is ___% of the CO2.
Alveoli
30%
When oxygen combines with hgb, it displaces _____
H+
The H+ that is displaced from hgb recombined with ______ for form carbonic acid which separates into _____ and _____.
Hco3-
CO2 and h2o
What happens to the CO2 and H20 from the dissociation of carbonic acid in phase 2 of CO2 tx? This CO2 is the ____% from phase 1.
Diffuse from the rbc through the plasma into the alveoli to be exhaled
65%
As hco3- decreases in phase 2 of CO2 tx, bc of the recombination with H+, hco3- moves into the ____ from the ______, and ________ shifts from the rbc back into the plasma; this is phase 2 of the ________ shift.
Hco3 moves into the RBC
From the PLASMA
CHLORIDE
Phase 2 of chloride shift
The majority (65%) of CO2 is transported in the blood as _______
Bicarb
Why do we see water and CO2 levels after intubation and correct tube placement?
Dissociation of carbonic acid in phase 2 of CO2 tx into CO2 and water
Average volume/size of RBC; femtoliters (fl)
Mean corpuscular volume (MCV)
Average amount of hgb; picograms
Mean corpuscular hgb
MCH
How concentrated is RBC with hgb
Mean corpuscular hgb concentration
MCHC
Variability in the size of RBC
Red cell distribution width (RDW)
If MCV stayed the same and MCH increased, then this lab value would increase.
MCHC
What could cause an increase in RDW?
Lots of reticulocytes
Normal serum iron level
50-150 micrograms/dl
Total iron binding capacity level (TIBC)
250-450 micrograms/dl
Serum ferritin levels?
20-300 ng/ml
Serum ferritin is the storage form of iron; acute phase protein. What will increase serum ferritin and what adjunct test can we use to see if elevated serum ferritin levels are accurate?
Any illness/infection/inflammation will increase serum ferritin sevens
C-reactive protein
Normal percentage transferrin saturation
~30%
Formula to calculate percentage transferrin saturation
Serum iron/TIBC x 100
Inflammatory protein; assesses presence of inflammation/infection and accuracy of serum ferritin as a reflection of iron stores
C-reactive protein
Normal RBC size term
Normocytic
Normal RBC hgb content term
Normochromic
Anemia type? Low H/H Low reticulocyte High MCV High plasma iron Normal TIBC High serum ferritin Low serum B12 Folate normal Sl. High bilirubin
Pernicious anemia
B12 deficiency
Which type of anemia is more prone to hemolysis, B12 def or folate def?
B12 deficiency anemia
Anemia type? Low H/H Low reticulocytes High Mcv High plasma iron Normal TIBC Normal serum ferritin Normal B12 Low folate Sl. High bilirubin
Folate def. anemia
Type of anemia: Low H/H Normal, high, or low reticulocytes Low MCV Low plasma iron High TIBC Low serum ferritin Normal: b12, folate and bilirubin
Iron deficiency anemia
Type of anemia?
Low H/H
High reticulocyte count
NORMAL: MCV, plasma iron, TIBC, serum ferritin, b12, folate, bilirubin
Posthemorrhagic anemia
Type of anemia? Low h/h High reticulocytes Normal or high MCV Normal/high plasma iron Normal: TIBC, Serum ferritin, b12, folate High bilirubin
Hemolytic anemia