Arterial Blood Gas

Question 1

What is the normal pH range?

Answer 1

pH 7.35 to 7.45

Question 2

When is the blood acidic?

Answer 2

when it is below pH 7.35

Question 3

When is the blood alkalotic?

Answer 3

when the pH is above 7.45

Question 4

Significant changes in the blood pH above ___ or below ___ will interfere with cellular ____, and if uncorrected will lead to ____.

Answer 4

above 7.8 or below 6.8
interfere with cell functioning
cell death

Question 5

Describe the Respiratory Buffer Response

Answer 5

when there is too much or too little CO2 in the blood - meaning there is a change in pH - it triggers the lungs to either INCREASE or DECREASE the rate and depth of ventilation. This happens until the appropriate amount of CO2 has been re-established. Activation of lungs occurs within 1 to 3min.

Question 6

Describe Renal Buffer response

Answer 6

when there is a change in pH level in the blood, the kidneys will either retain or excrete bicarbonate HCO 3- . As the pH decreases, the kidneys will compensate by retaining HCO 3-. As the pH rises the kidneys will excrete HCO3- through urine. This occurs slowly, hours or days to occur.

Question 7

Respiratory acidosis is defined as?

Answer 7

pH less than 7.35 and PaCo2 greater than 45 mm Hg.

Question 8

What causes respiratory acidosis?

Answer 8

Accumulation of CO2 causes respiratory acidosis, which combines with water in body to produce carbonic acid, thus lowering the pH of blood. Any condition that results in hypoventilation can cause this *

Question 9

What are some conditions that can cause respiratory acidosis?

Answer 9

• CNS depression related to head injury
• CNS depression related to medications (narcotics, sedatives, or anesthesia)
• Impaired resp muscle function related to SCI, neuromuscular diseases or neuromuscular blocking drugs
• pulmonary disorders (atelectasis, pneumonia, pneumothorax, pulmonary edema, bronchial obstruction)
• massive pulmonary embolus
• Hypoventilation due to pain, chest wall injury/deformity, abdominal distension.

Question 10

What are some signs and symptoms of respiratory acidosis?

Answer 10

Pulmonary:
-dyspnea
-respiratory distress
-shallow respirations
Nervous system:
-headache
-restlessness
-confusion
for extreme* - drowsiness and unresponsiveness 
Cardio:
- tachycardia
-dysrhythmias

Question 11

What will correct resp acidosis?

Answer 11

Increasing ventilation

Question 12

What is Respiratory Alkalosis?

Answer 12

Defined as a pH greater than 7.45 and PaCo2 less than 35 mm Hg.

Question 13

Respiratory Alkalosis conditions?

Answer 13

Any condition causing hyperventilation can result in this.

• Psychological responses (anxiety, fear)
• Pain
• Inc metabolic demands (fever, sepsis, pregnancy, thyrotoxicosis)
• Medications such as resp stimulants
• CNS lesions

Question 14

What are signs and symptoms of Respiratory alkalosis?

Answer 14

Nervous system:
-light headedness
-numbness
-tingling
-confusion
-inability to concentrate
-blurred vision
Cardiac:
-dysrhythmias
-tetanic spasms of arms and legs

Question 15

What is Metabolic acidosis?

Answer 15

Defined as a bicarbonate (HCO3-) level of less than

22 mEq/L with a pH of less than 7.35.

Question 16

What causes a metabolic acidosis?

Answer 16

caused by either a deficit of base in the blood, or an excess of acids, other than CO2. Diarrhea or fistulas may cause dec levels of base.

increase of acids:

• renal failure
• diabetic ketoacidosis
• anaerobic metabolism
• starvation
• salicylate intoxication - NSAIDS

Question 17

What are symptoms of metabolic acidosis?

Answer 17

Nervous S:
-headache
-confusion
-restlessness progressing to lethargy
-stupor or coma
Cardiac:
-dysrhythmias 
-Kussmaul respirations (deep and labored breathing) - in an effort to blow off more CO2 
- warm and flushed skin, as well as nausea and vomiting are commonly noted*

Question 18

What us hypoxemia?

Answer 18

low oxygen level in the blood

Question 19

What is hypoxia?

Answer 19

deficiency in amount of O2 reaching the tissues

Question 20

What is perfusion?

Answer 20

blood flow through capillary bed

Question 21

what is lethargy?

Answer 21

lack of energy and enthusiasm

Question 22

What is stupor?

Answer 22

state of near unconsciousness or insensibility

Question 23

What is metabolic alkalosis?

Answer 23

Bicarbonate level greater than 26 mEq/ L with a pH greater than 7.45.

Question 24

Why does metabolic alkalosis occur?

Answer 24

either an excess of base or a loss of acid within body.
Excess of base occurs from ingestion of antacids, excess use of bicarbonate, or use of lactate in dialysis. Loss of acids occur secondary to protracted vomiting, gastric suction, hypochloremia, excess administration of diuretics or high levels of aldosterone

Question 25

What are symptoms of metabolic alkalosis?

Answer 25

Nuero:
-dizziness
-lethargy
-disorientation
-seizures
-coma
MSK:
-weakness
-muscle twitching
-muscle cramps
-tetany 
* may also experience nausea, vomiting, resp depression 
-in hospitalized patients is usually iatrogenic in nature (caused by treatments or med exam)
* one of the most difficult acid-base imbalances to treat

Question 26

Define pH

Answer 26

measurement of acidity or alkalinity, based on the hydrogen (H+) ions present
normal 7.35 to 7.45

Question 27

PaO2? normal range?

Answer 27

the partial pressure of oxygen that is dissolved in arterial blood.
normal range is 80 to 100 mm Hg

Question 28

SaO2? normal range?

Answer 28

the arterial oxygen saturation

normal range is 95-100%

Question 29

PaCO2? normal range?

Answer 29

amount of carbon dioxide dissolved in arterial blood (partial pressure). normal range is 35 to 45 mm Hg

Question 30

HCO3- ? normal range?

Answer 30

Bicarbonate, calculated in the blood

normal range is 22 to 26 mEq/L

Question 31

B.E. ? normal range?

Answer 31

the base excess indicates the amount of excess or insufficient level of bicarbonate in the system
Normal is -2 to +2 mEq/L