Exam 1 Edema, Electrolytes, A/B, Cardiac Flashcards
What barorecptors monitor BP?
Carotid sinus and aortic arch
What apparatus monitors pressure changes?
Juxtaglomerular
The baroreceptors of heart activate what mechanisms?
Neural, RAAS, ANP, ADH
How does the body regulate fluid volume and composition both intracelluarly and extracellularly?
By regulating volume and composition of blood
What is the dominant ECF cation?
Na+
What is responsible for 90-95% of osmotic pressure in ECF?
Na+
What does osmolality measure?
Concentration
What does osmolality regulation depend on?
How much water is present
What is the primary hormonal control of osmolality?
ADH
What forces favor filatration?
Capillary hydrostatic pressure (blood pressure)
Interstitial oncotic pressure (water-pulling)
What forces favor reabsorption?
Plasma oncotic pressure (water-pulling)
Interstitial hydrostatic pressure
ECF volume may vary even if osmolality of ECF is maintained? T or F
True
What is accumulation of fluid within the interstitial spaces?
Edema
What are causes of edema?
Increase in hydrostatic pressure
Losses or dim production of plasma albumin
Increases in capillary permeability
Lymph obstruction
What are the local clinical manifestations of edema?
Limited to site of trauma
Includes cerebral, pulmonary, pleural effusion, pericardial effusion, ascites
What are the generalized clinical manifestations of edema?
More systemic
Dependent edema accumulates in a gravity dependent manner
Other clinical manifestations of edema
Increased distance for diffusion of O2 so less gets to cells
Decreased blood flow leads to poor wound healing
Dehydration due to fluid not available for metabolis or perfusion
What is an example of edema?
Fluid sequestration following severe burns leads to shock
What is tightly regulated ECF due to influences on volume?
Na+
Small quantities of Na+ are lost in what?
Sweat= water, Na+, urea, Cl-, K+, NH3
What happens when Na+ is low and H2O moves into cells?
Hypotonic- cell swell
What happens when Na+ is too high and water moves out of cell?
Hypertonic solution- cell shrink
What happens with Na+ and water are stable in the cells?
Isotonic solution-no change
What are the 3 fluid compartments in the brain?
Blood
ECF and ICF
CSF
Is there a fixed volume in the cranium?
Yes
If you increase the fluid in one compartment in brain then what must happen to other two compartments?
Must decrease
Hyponatremia alters what function?
Neurlogic
Rapid shrinking can do what to the brain?
Tear vessels and cause hemorrhage
Rapid swelling can do what to the brain?
Herniation
What factors regulate Na+ retention?
Estrogens
Glucocorticoids
Osmotic diuretics
Poorly reabsorbed anions
Diuretic drugs
Dopamine
How does glucocorticoids regatulate Na+ retention?
Increase Na+ retention
How do osmotic diuretics regulate Na+ retention?
Decrease Na+ retention
How does poorly reabsorbed anions regulate Na+ retention?
Decrease Na+ retention
How does dopamine regulate Na+ retention?
Increases Na+ retention
Where is 98% of our total body K+ found?
Intracellular
What is circumferential range of K+?
0.3 range of 4.2 (3.9-4.5)
What is the major determinant of intracellular volume?
K+
What can serve as a outflow site for excess extracelluar fluid during hyperkalemia or hypokalemia?
Cells
What is 1st line of defense against changes in K+?
Redistribution
What does K+ establish with the heart?
Resting membrane potential
Low K+ will do what to the RMP?
Increase RMP (make it more negative)
Decrease excitability
High K+ will do what to the RMP?
Decrease RMP (makes it more pos)
Increase excitability
Acidosis will do what to the K+?
Increase it (hyperkalemia)
Alkalosis does what to the K+?
Lower K+ (hypokalemia)
K+ effects what ezymes?
Ones involved in carb metabolism and electron transport
How does increased aldosterone effect K+?
Causes K+ excretion
Increase permeability of luminal membrane permeability to K+
What disorders of aldosterone synthesis affect K+ regulation?
Addison’s Dx
Cohn’s Syndrome
How does K+ regulation effect tubular flow rate?
Increased tubular flow rate
The higher the concentration gradient then the more or less K+ is lost?
More
Hyperkalemia results from what?
Increased intake
Renal failure
Crushing injuries
Acidosis
What are symptoms of hyperkalemia?
muscular weakness
Irritability
Vent fib.
EKG changes
Hypolakemia results from what?
Excessive loss (diarrhea) or decreased intake
Kidney dx
Certain diuretics-lasix
Hypokalemia causes what symptoms?
Muscle fatigue
flaccid paralysis
mental confusion
Increased urine output
EKG changes
What is 99% of Ca+ found?
Bone
What stimulates osteocytes to deposit Ca+ within bone?
Calcitonin (CT)
What does Parathyroid hormone cause?
Bone resorption (osteoclasts)
Increase rental tubular reabsorption
Stimulates Vit D which increases intestinal absorption of Ca+
Acidosis frees Ca+ from what?
Proteins
Alkalosis will increase or decrease the percent of Ca+ bound to proteins?
Increase
How is most Ca+ excreted from body?
Feces (900-1000 mg/day)
Metabolic acidosis increases or decreases in Ca+ reabsorption?
Increases
Metabolic alkalosis increases or decreases Ca+ reabsorption?
Decreases
How does hypercalcemia affect the neuromuscular excitability and heart?
Causes neuromuscular excitability depression
Cardiac arrhythmias
Hypocalcemia has what affect on neuromuscular and heart?
Increase nerve and muscle excitability
Tetany
What changes the RMP?
K+
How does low K+ affect heart?
Decrease excitability
RMP more neg
Harder to get AP
How does high K+ affect RMP?
Increase excitability
Makes RMP more pos
Easily to excite and get AP
What does Ca+ effect in heart?
Threshold
By affecting Na+ entry into cells
How does high Ca+ affect threshold?
Increase threshold
Make cells less excitable
Harder to get AP
What are 3 ways the body regulates pH?
Chemical buffers (bicarbonate, proteins, phosphate)
Lungs
Kidneys
What is the main buffer in the ECF?
Bicarbonate
What is respiratory acidosis?
Low pH
High CO2
What is respiratory alkalosis?
High pH
Low CO2
What is metabolic acidosis?
Low pH
Low HCO3
What is metabolic alkalosis?
High pH
High HCO3
Normal anion gap?
8-16
What is normal anion gap?
Increased Cl-
Sum of Cl- and HCO3 normal
AKA hyperchloremic acidosis
Causes of normal anion gap ?
Diarrhea (most common)
Renal tubular dysfunction
Ammonia chorlide ingestion
Carbonic anhydrase inhibitors
What is increased anion gap?
Normal Cl-
Increased levels of unmeasured anions
What are examples of increased anion gap?
MUD PILERS
Methanol poisoning
Uremia (renal failure)
DKA (ketoacidiosis, starvation)
Pa-P-Aldehyde intoxication
Isoniazid
Lactic acidosis
Ethylene glycol poisoning (antifreeze)
Renal failure
Salicylate poisoning
Where is two thirds of the body’s water?
Intracellular fluid (ICF)
Where is one third of the body’s water?
Extracelluar fluid (ECF)
What are the two main components of the ECF?
Interstitial fluid and intravascular fluid (plasma/blood)
What is the standard value for total body water (TBW)?
60% of weight of 70 kg adult male
Hormonal regulation of Na+ balance is mediated by what?
Aldosterone
What happens in the kidneys when the blood pressure or blood volume is low?
Renin is released to convert AGI to AGII
What are the two main functions of AGII?
Vasoconstriction (increases BP)
Simulates secretion of aldosterone (promote Na+ and H20 reabsorption)
What is a major factor in regulating potassium?
Aldosterone
How does insulin affect K+?
Moves K+ into cells to lower K+ in blood by stimulating NaK pump
What provides the most efficient regulation of K+ balance over time?
Kidneys
What do principal cells in collecting duct do?
Secrete K+
What do intercalated cells in collecting duct do?
Reabsorbed K+
What hormone gets secreted due to low levels of Ca+?
Parathyroid hormone
What is anemia?
Decrease in # of circulating RBCs or decrease in quality or quantity of HGB
What is anemia a sign of?
Another underlying problem
It is not the primary issue
What are the causes of anemia?
Altered RBC production
Blood loss
Increased RBC destruction
Combination of all three
What is anemia classification based on?
Morphology
What is the size of RBC identified by?
Terms that end in “-cytic”
Macrocytic, Microcytic, normocytic
What is the hemoglobin content identified by?
Terms that end in “-chromic”
Normonchromic and hypochromic
What type of anemia is B12 or folate deficiency?
Macrocytic-Normochromic
What type of anemia is iron deficiency or thalassemia?
Microcytic-Hypochromic
Hgb don’t form properly
What type of anemia is hemorrhage, hemolytic, aplastic?
Normocytic-Normchromic
What is the genetic dx with low O2 and hgb forms irregular shape which clogs capillaries?
Sickle cell dx
What are the manifestations of anemia?
Hypoxia- fatigue, weakness, dyspnea, angina
How does the body compensation for anemia?
Attempts to increase cardiac output by increasing rate and strength of contraction
What is polycytemia?
Increase RBC production
What is difference between relative and absolute polycythemia?
Relative- blood thicker due to dehydration for example
Absolute- issue with erythropoietin so increases it
What is the issue with anemia in cardiac dx patients?
Increase HR to compensation can be bad for these pts
What is most compensation of anemia related to?
Cardiac
What happens in anemia?
Decrease O2 carrying capacity (hypoxemia)
Leads to tissue hypoxia
What is anemia of chronic dx?
Mild to moderate anemia from decreased erythropoiesis
What are some pathological mechanisms of anemia of chronic dx?
Decreased erythrocyte life span
Suppressed production of erythropoietin
Ineffective bone marrow response to erythropoietin
Altered iron metabolism
What is aplastic anemia?
Pancytopenia (reduction or absence of all 3 types of blood cells)
RBC, WBC, PLT
What type of disorders are most aplastic anemia?
Autoimmune disorders
Some are due to chemicals, drugs, physical agents
What is pathophysiology of aplastic anemia?
Hypocelluar bone marrow that has been replaced with fat
What are the signs of aplastic anemia?
Hypoexemia
Pallor (brownish pigment of skin)
Weakness
Fever
Dyspnea
Rapidly developing signs of hemorrhaging if plts affected
What is aplastic anemia a failure or suppression of?
Failure or suppression of bone marrow to produce adequate amounts of blood cells
What anemia is common due to drug effects?
Aplastic anemia
What drugs are known to cause aplastic anemia?
ABX (Chloramphenicol)
Anticonvulsants (Phenytoin, Mephenytoin)
Anti-inflammatories (ibuprofen)
Benzene
What is hemolytic anemia? What are 2 types?
Accelerated destruction of RBCs
Can be congenital (newborn) vs acquired (drug induced)
What is autoimmune hemolytic anemia?
Autoantibodies against antigens normally on surface of erythrocytes
What is a form of immune hemolytic anemia that is the result of allergic reaction to foreign antigens?
Drug induced hemolytic anemia
Called hapten model
What drugs can cause drug induced hemolytic anemia?
ABX
Penicillin
Cephalosporins (more than 90%)
Hydrocortisone
What is the drug induced hemolytic anemia called?
Hapten model
What is the hapten model with drug induced hemolytic anemia?
IgG antibody against drug or against unique antigen formed by interface of drug and erythrocyte protein is formed and binds to erythrocyte at normal body temperature
Where does hemolysis occur with drug induced hemolytic anemia?
Extravascular
What can rapidly resolve drug induced hemolytic anemia?
Cessation of drug administration
What are signs of drug induced hemolytic anemia?
Asymptomatic
Jaundice (icterus)
Aplastic crisis
Splenomegaly
What type of anemia is commonly noted in presence of CHF?
Anemia of chronic dx
How is hemolytic anemia divided into categories?
Congenital or acquired
Acquired is drug induced form
How does hemolytic anemia occur?
Occurs in blood vessls (intravascular) or lymphoid tissues (extravascular) that filter blood
Spleen or liver
What is intravascular hemolysis?
Least common
Caused by physical destruction of RBCs in circulation
What is extravascluar hemolysis?
Results from removal of damaged or opsonized RBCs by cells of mononuclear phagocyte system (MPS)
What is the most common type of megaloblastic anemia caused by vitamin B12 deficiency?
Pernicious anemia
What is folate deficiency anemia?
Impaired DNA synthesis secondary to folate deficiency cause megaloblastic cells with clumped nuclear chromatin
Folic acid is essential for RNA and DNA synthesis
What type of anemia is iron (fe) deficiency anemia?
Microcytic-Hypochromic anemia
What is the most common type of anemia worldwide?
Iron deficiency anemia
Who has higher risk for iron deficiency anemia? Males or females
Females
What are the 2 main causes of iron deficieny anemia?
Inadequate dietary intake
Excessive blood loss
(There is not intrinsic dysfunction of iron metabolism)
Both deplete iron stores & reduce iron metabolism
What is another cause of iron deficiency anemia?
Due to metabolic or function iron deficiency in which various metabolic disorders lead to either insufficient iron delivery to bone marrow or impaired iron use within marrow
What is the common cause of iron deficiency anemia in developed countries?
Pregnancy and chronic blood loss
Iron in the form on hgb is in constant demand by the body? T or F
True
How does blood loss affect iron?
Disrupts balance by creating need for iron which depletes iron stores more rapidly to replace iron lost from bleeding
How is iron deficiency related to supply and demand?
Occurs when demand for iron exceeds the supply of iron
Develops more slowly through 3 overlapping stages
What are the stages of iron deficiency anemia?
Stage 1: body’s iron stores are depleted (hgb content normal)
Stage 2: iron transport to bone marrow decreases
Stage 3: small hgb deficient cells enter circulation to replace normal age RBCs that are removed from circulation (s/sx occur)
What are signs of iron deficiency anemia?
Pallor skin and eyes
Brittle nails with spoon shape
Glossitis (tongue bald appearance with loss of papillae)
What converts fibrinogen to fibrin?
Thrombin
Where do we see most deficiency in clotting cascade?
Near the end of clotting cascade
Rarely see in beginning with TF
What is Vit C deficiency?
Lack of stable collagen
What patients have Vit C deficiency?
elderly
Alcoholics
What does hepatic failure cause?
Depletion of clotting factors
Where are almost all clotting factors made?
Liver
What is Vit K deficiency?
Depletion of factors 2 (prothrombin), 7, 9, 10, and protein C & S
II, VII, IX, X
What is Vit K deficiency due to?
Fat malabsorption due to lack of bile secretion