Acid base disorder

Question 1

Arterial Sample

Peripheral venous sample

Central Venous Sample

Answer 1

• 7.35-7.45
• pH is usually .02-.04 units lower than in arterial, HCO3 concentration 1 to 2 meq/L higher and PCO2 is usually 3 to 8 mmHg higher
• Usually 0.03 to 0.05 pH units lower and PCO2 is 4 ro 5 mmHg higher. Little or no incease in serum

Question 2

An arterial pH below the norm

less than 7.35

Answer 2

Acidemia

Question 3

An arterial pH above normal range

>7.45

Answer 3

Alkalemia

Question 4

A process that tends to lower the extracellular fluid pH (H ion concentration increases). THis can be caused by a fall in serum bicarb concentration and or an elevation in PCO2

Answer 4

Acidosis

Question 5

A process that tends to raise the extracellular fluid pH (H+ concentration is lower). This can be caused by increased serum bicarb and/or fall in PCO2

Answer 5

Alkalosis

Question 6

HCO3 <21 and/or PCO2 > 45

Answer 6

Acidosis

Question 7

HCO3 > 30 and/ or PCO2 <35

Answer 7

Alkalosis

Question 8

A disorder that causes reductions in the serum HCO3 concentration and pH

Answer 8

Metabolic acidosis

Question 9

A disorder that causes elevations in the serum HCO3 concentration and pH

Answer 9

Metabolic Alkalosis

Question 10

A disorder that causes an elevation in arterial PCO2 and a reduction in pH

Answer 10

Respiratory acidosis

Question 11

A disorder that causes a reduction in arterial PCO2 and an increase in pH

Answer 11

Respiratory alkalosis

Question 12

The presence of one of the Metabolic/Respiratory disorders with the appropriate respiratory or renal compensation for that disorder.

Answer 12

Simple Acid-Base Disorder

Question 13

The presence of more than one acid-base disorder

Answer 13

Mixed disorder

Question 14

Arterial pH

Normal

Alkalemia/Alkalosis

Acidemia/Acidosis

Panic values

Answer 14

• 7.35-7.45
• >7.45
• <7.35
• >7.55 or <7.25

Question 15

Acidemia produces __ K+

Alkalemia produces ___ K+

pH change of 0.1 is associated with __ change in serum K+

Prolonged acidosis:?

Answer 15

• Higher
• Lower
• 0.6 change in opposite direction
• Renal K+ wasting

Question 16

Arterial pCO2

Normal

Acidemia/acidosis

Alkalemia/alkalosis

Increased with ____ respiratory rate or tidal volumes

Decreased with ____ respiratory rate or tidal volume

Answer 16

• 35-45 mmHg
• >45 mmHg
• <35 mmHg
• decreased
• increased

Question 17

Arterial pO2

normal

Increased with ____ respiratory rate

Decreased with ___ respiratory rate

Panic value?

Answer 17

80-100

Increased

Decreased

<60mmHg

Question 18

Bicarb

Arterial serum normal range

Alkalemia/Alkalosis

Acidemia/Acidosis

Answer 18

21-30

>30

<21

Question 19

O2 saturation

Normal

Goal>__ with mechanical ventilation or > __ ambulatory

Answer 19

• 90%
• 92%

Question 20

In pts with metabolic acidosis, determine if the anion gap is?

Calculated by?

Answer 20

• elevated >12
• Cation - Anion

Question 21

Six step process for determining acid - base disorder

Answer 21

1. Is the pt acidemic or alkalemic?
2. Is the overriding disturbance respiratory or metabolic?
3. If respiratory is it acute or chronic?
4. If metabolic is there a high anion gap?
5. If metabolic is there a respiratory system compensating appropriately?
6. Is there a second metabolic disturbance present?

Question 22

3 step for determining acid-base disorder?

Answer 22

1. Is there a problem?
   
   1. Determine pH
2. Establish the primary process/diagnosis (metabolic vs. respiratory)
3. Determine compensation

Question 23

Respiratory vs metabolic

Answer 23

• pH matching pCO2 (lungs)
  
  • pCO2 >45 or <35
  • pH 7.55 and pCO2 25 then = respiratory alkalosis
• pH matching HCO3-
  
  • >30 or <21 and matches the pH
  • pH 7.3 and HCO3- 16 = metabolic acidosis

Question 24

Determining compensation

Answer 24

• Find the value that does not match the pH and determine if the body has attempted to correct the problem
• If pCO2 or HCO3- are abnormal in the opposite direction of the pH then there is compensation
• if pCO2 or HCO3- are not abnormal then there is no compensation
• Complete compensation occurs when the pH is normal but the pCO2 and HCO3- are abnormal (can also be mixed)

Question 25

Metabolic compensation

Acute and Chronic Hypercapnia

Answer 25

• HCO3 increases 1 for each 10 mmHg increase in PaCO2>40
• HCO3- increases 3.5 for 10 mmHg increase in PaCO2 >40

Question 26

Metabolic compensation

Acute/Chronic Hypocapnia

Answer 26

Question 27

Metabolic acidosis

Alkalosis

Respiratory acidosis/alkalosis

Answer 27

• A disorder that causes reductions in the serum HCO3 concentration and pH.
• A disorder that causes elevations in the serum HCO3 concentration and pH.
• A disorder that causes an elevation in arterial PCO2 and a reduction in pH.
• A disorder that causes a reduction in arterial PCO2 and an increase in pH.

Question 28

Metabolic acidosis

Anion gap

MUDPILES- Anion Gap

USED CARS Non-anion gap

Answer 28

• M-Methanol
• U-Uremia
• D-DKA
• P- eraldehyde
• I- Intoxication
• L- Lactic acidosis
• E- Ethylene Glycol
• S-Salicylates
• U-Uterosigmoid diversion
• S-Saline
• E-EtOH
• D- Diarrhea
• C- Carbonic anhydrase inhibitors
• A-Alcohol, Addisons disease/Cushing
• R- Renal Tubular Acidosis
• S-Saline?

Question 29

Metabolic Alkalosis

Answer 29

• Alkali ingestion
• Vomiting or NG suction
• Fluid volume contraction
• Hypokalemia
• Cushings disease, glucocorticoids, mineralocorticoids, post-chronic hypercapnia
• Massive blood transfusion (whatpreservative?)
• Ingestion or administration of bicarb
  
  • Mile-alkali syndrome

Question 30

Respiratory Acidosis

Hyperventilation

Answer 30

Question 31

Respiratory alkalosis

Answer 31

Question 32

Metabolic Acidosis

Gap or non gap?

Answer 32

Gap >12

Non gap 12 or less

Question 33

Step 3a determine gap

Answer 33

In pts with metabolic acidosis, determine if anion gap is elevated

Cation-Anion

>12 gap, metabolic acidosis