acid-base balance

Question 1

occlude both ulnar and radial artery until hand blanches then release ulnar. If the
hand pinks up, ulnar artery is good and you can carry on with ABG/radial stick as planned. ABGS
must be put on ice and whisked to the lab.

Answer 1

allen’s test

Question 2

a test performed on arterial blood to determine levels of oxygen, carbon dioxide, and other gases present

pH
paCO2
HCO3
PaO2
SaO2

Answer 2

arterial blood gases (ABGs)

Question 3

normal pH range (acid-base balance)

Answer 3

7.35 - 7.45

Question 4

normal paCO2 range (carbon dioxide)

Answer 4

35 - 45

Question 5

normal HCO3 range (bicarbonate)

Answer 5

21 - 28

Question 6

normal PaO2 range (oxygen)

Answer 6

80 - 100

Question 7

normal SaO2 range (oxygen saturation)

Answer 7

5 - 100%

Question 8

The kidneys are the most powerful regulator of acid base balance

To decrease the pH kidneys will increase the kidneys excretion of bicarbonate and increase the kidney reabsorption of hydrogen ions.

To increase pH the kidneys will decrease excretion of bicarbonate and decrease reabsorption of hydrogen ions.

Answer 8

kidney’s role in acid-base balance

Question 9

*Chemical pairs that maintain normal pH
*Acids release H+
*Bases use H+
*Buffers release or remove H+ to restore normal pH
*Bicarbonate (HCO3) is major buffer in ECF

Answer 9

acid buffers

Question 10

pH less than 7.35

• The blood has too much acid (or too little base), resulting in a decrease in blood pH

Answer 10

acidosis

Question 11

*pH less than 7.35 HCO3 less than 22 PaCO2 normal
*Causes
*Increased metabolic acid
*Ketoacidosis
*Hypermetabolic state
*Renal failure
*Circulatory shock
*Loss of bicarbonate
*Severe diarrhea
*Pancreatic fistula
s/s:CNS depression - lethargy, confusion.
Neuromuscular - hyporeflexia, muscle weakness, flaccid paralysis

Answer 11

metabolic acidosis

Question 12

*pH below 7.35 PaCo2 greater than 45
*Causes
*Hypoventilation
*COPD
*Airway obstruction
*Acute asthmaticus
*Diaphragm impairment
*Atelectasis
*Respiratory depression
-Acidosis reduces the excitability of cardiovascular muscle, neurons, skeletal muscle, and GI smooth muscle.
Respiratory Acidosis - Caused by retention of CO2
Respiratory depression
Anesthetics
Drugs (opioids)
Electrolyte imbalance
Inadequate chest expansion
Muscle weakness
Airway obstruction
Alveolar capillary block

Answer 12

respiratory acidosis

Question 13

pH above 7.45

• the blood has too much base (or too little acid), resulting in an increase in blood pH

Answer 13

alkalosis

Question 14

*PH > 7.45 HCO3 > 26 PaCO2 normal
*Increased bicarbonate from
*Massive blood transfusion
*Ecv deficit
*Loss of metabolic acid from
*Excessive vomiting
*NG tube suctioning
*Hypokalemia
*Excessive aldosterone
-Clinical Manifestations
CNS -(related to hypocalcemia and hypokalemia) increased activity, anxiety, irritability, tetany, seziures.

Answer 14

metabolic alkalosis

Question 15

*pH greater than 7.45 PaCo2 less than 35 HCO3 normal
*Causes
*Hyperventilation
*Hypoxemia
*Acute pain
*Anxiety
*Some head injury

Answer 15

respiratory alkalosis

Question 16

Ph & HCO3 low – PaCo2 low

Answer 16

compensated metabolic acidosis

Question 17

Ph low & PaCo2 high – HCO3 high

Answer 17

compensated respiratory acidosis

Question 18

PH & HCO3 high – PaCo2 high

Answer 18

compensated metabolic alkalosis

Question 19

HCO3 & PaCo2 abnormal – Ph normal

Answer 19

fully compensated

Question 20

• Excrete carbonic acid in form of Co2
• Carbon dioxide regulation
• An increase in co2 will decrease pH
• A decrease in Co2 will increase pH
• Changes in the speed and depth of breathing will change pH quickly

Answer 20

role of lungs in acid-base balance