2nd semester Resp Phy. #1

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2nd semester Resp Phy. #1
2014-02-05 01:01:55
Intro ABGs

2nd semester
Show Answers:

  1. What are the 3 things that ABG's can diagnose and manage within a patient?
    1. Oxygenation

    2. Ventilation

    3. Acid-base status
  2. what is the perfect middle # of pH that helps us to know what side of normal we are at to interpret a gas?
    the range is 7.35-7.45. So 7.40 is the perfect middle.
  3. What ABG does "Ventilation" deal with?
    Patients CO2 levels
  4. A patient that is breathing hard and fast with a CO2 level of 50 mmHg is "hyper" or hypo" ventilating ?
  5. Is a PaO2 of 60mm Hg good?
    yes because on the oxygen disassociation curve 60 mm Hg carries a 90% saturation of hemoglobin with oxygen.
  6. What is the normal "PaCO2" range?

    What is it called if it is ABOVE or BELOW that range?
    35-45 mm Hg

    Less than 35 is Hyperventilation

    Greater than 45 is Hypoventilation
  7. What does pH measure?
    acidity or alkalinity of a fluid
  8. What is the pH of water ?

    What is it called if it is above or below its normal pH?

    > 7.0 = alkaline

    < 7.0 = acid
  9. What is the blood pH range?

    What is it called if it is above or below its normal pH?
    7.35 - 7.45

    >7.45 = alkalosis

    <7.35 = acidosis
  10. What is the normal HCO3?
    22 - 26 meq/L
  11. What does pH reflect?
    the acid-base status of the body
  12. What is "Acidosis" ?
    • too much acid/too little base
    •  -pH less than 7.35
  13. What is "Alkalosis" ?
    • too much base/too little acid
    • -pH greater than 7.45
  14. What are the normal hemoglobin levels ?
  15. Why do people with anemia often feel very sluggish?
    Because they have low hemoglobin levels, so their content of oxygen isn't as available = feeling sluggish
  16. What is the formula to figure out the content of CaO2?
    CaO2 = (Hgb x Sat x 1.34) + (PaO2 x .003)

    answer is in "vol %"
  17. What does "Vol %" mean, and what are the normal Vol % of CaO2 for venous and arterial?
    means = mLO2/100 ml of blood

    15% for venous

    20% for arterial
  18. What is a "acid" ?
    a compound which donates a hydrogen ion (H+)
  19. What does a strong acid do in a aqueous solution (water) ?

    Name one strong acid.
    The ionize almost completely (virtually 100%).

    Hydrochloric acid

    HCL        H+   +    CL-
  20. What does a weak acid do in a aqueous solution (water) ?

    Name one weak acid.
    It ionizes only to a small extent when dissolved in water. (makes a good buffer)  

    Carbonic acid is a weak acid

    CO2 + H2O    H2CO3       H+   +   HCO3-
  21. What is a "Base" ?
    A substance which can accept a H+  ion (OH-)

    • H+      +     OH-    =    H2O
    • ACID          BASE        NEUTRAL
  22. 1. What is a "Buffer" ?

    2. Will addition of a acid or base dramatically change the pH?

    3. What is buffering essential to?

    4. Name 3 Buffering mechanisms?
    1. A solution that is resistant to changes in pH.

    2. No.

    3. Essential to acid base balance

    4. Body fluids, Respiration,  & Kidneys
  23. What is a "Volatile Acid" ?

    Name the only significant volatile acid.
    One that is in equilibrium with a dissolved gas.

    Carbonic Acid = H2CO3 

    it is in equilibrium with dissolved Carbon Dioxide (CO2)
  24. What does the kidney do with the "H+" and HCO3-" when a patient "hypoventilates"?
     Ex patient: COPD patient

    (Too much CO2 due to hypoventilation)

    Hypoventilation results in increased H+ in the blood (too little HCO3-)

    In response the kidney buffers by dumping the H+ and saving the HCO3-.
  25. What does the kidney do with the "H+" and "HCO3-" when a patient " hyperventilates" ?
    Ex patient: Asthma patient

    (Too little CO2 caused by hyperventilation)

    Hyperventilation results in reduced H+ in blood (too much HCO3-)

    In response the kidney buffers by saving H+ and dumping the HCO3-
  26. What is the most common cause of  respiratory alkalosis?
  27. What does "respiratory acidosis" mean? and what happens to correct this ?
    Means the patient is hypoventilating.

    To fix this the kidneys restore the pH toward normal by reabsorbing HCO3- into the blood.
  28. What does "respiratory alkalosis" mean? and what happens to correct this ?
    Means the patient is hyperventilating.

    To fix this the kidneys release HCO3- into the urinary system. (bicarbonate diuresis).
  29. If a nonrespiratory (metabolic) process decreases or increases (HCO3-) what happens to correct this ?
    The lungs compensate by hyperventilating (eliminating CO2) or hypoventilating (retaining CO2) to restore the pH back to normal.
  30. What is the name for the nonrespiratory name for the process causing acidemia called?
    Metabolic acidosis.
  31. What is the name for the nonrespiratory process that increases arterial pH by losing fixed or gaining HCO3-?
     Metabolic alkalosis
  32. What two things work together to help maintain a blood pH of 7.4 by affecting the components of the buffers in the blood?
    Kidneys  & the Lungs

    resp. problem ----> Renal buffering

    Metabolic problem ----> resp. buffering
  33. Name two fixed acids ?
    Lactic and keto acids
  34. In respiratory buffering how long does it take to have an affect on the pH?

    is it limited? (does it have a PCO2 max)  
    1. Quick affecting pH within minuets

    2. It is limited to a PCO2 max of 55
  35. In renal buffering how long does it take for full compensation?

    is it limited ?
    1. Slower requiring 2 - 3 days before full compensation

    2. Unlimited
  36. What is the "Henderson Hassel Bach Equation"? explain the parts of it.
    • (Clinical pH Equation) 
    •                                  HCO3-
    • pH = 6.1  + log   --------------------
    •                            0.0301 x PCO2

    6.1 (aka:PK) = constand that tells us about the disassociation

    Log = Base power used to make the value a whole number

    HCO3- = Bicarbonate the base

    .03 x PCO2 = Dissolved CO2 the acid
  37. What is a simplified way to show the clinical pH equation?
  38.          Base                          HCO3-
    • pH = -------              pH = ----------
    •          Acid                           CO2
  39. Does the body handle higher or lower CO2 levels best?
  40. What happens when there is excessive excretion of CO2 and the PaCO2 is less than 35 mm Hg? 

    what corrects this ?
    1. Resp. Alkalosis

    2. Kidney saves acid and dumps base (weird wording??)
  41. What are 3 causes of resp. alkalosis?
    1. Hyperventilation due to anxiety

    2. Hypoxemia (#1 REASON!!)

    3. Any cause of hyperventilation
  42. What happens when there is an inadequate excretion of CO2, and the PaCO2 is more than 45 mm Hg?

    what corrects this?
    1. resp. acidosis

    2. kidney dumps acid and saves base (weird wording??)
  43. What are 3 causes of resp. acidosis?
    1. Obstructive lung diseases (COPD)

    2. Over sedation

    3. Any cause of hypoventilation
  44. What is the result when there is a loss of H+ or a gain of HCO3-?

    what corrects this? (2)
    1. Metabolic Alkalosis

    2. Immediate: Hypoventilation and overtime the kidney saves H+ and dumps HCO3-
  45. What are 3 causes of Metabolic alkalosis?
    1. Loss of positive charges electrolytes such as H+, K+

    2. Low Cl- secondary to loss of HCL from stomach

    3. Excessive use of antacids
  46. What is the result when there is a gain of H+ or loss of HCO3- ?

    what corrects this? (2)
    1. Metabolic acidosis

    2. Immediate : Hyperventilation, and over time the kidney saves HCO3- and dumps H+