Lungs

1
Lungs

• The lungs regulate
• The Carbonic acid level / CO2
• The lungs are able to retain as well as excrete
• CO2

2
Lungs
AAA BBB
CO2
CO2
3
Lungs

• Decrease in respiratory rate
• h CO2 (acid)
• i pH
• Increase in respiratory rate
• i CO2 (acid)
• h pH

4
Lungs
AAA BBB
CO2 Hypoventilate
CO2 Hyperventilate
5
Lungs

• If the plasma pH is acidic (i pH 4A gt 3B or 3A
  gt 2B) the lungs will try to restore balance by
• Hyperventilating
• i CO2
• h pH
• 4A gt 3B ? 3A 3B

6
Lungs

• If the plasma pH is alkaline (h pH 3A lt 4B or
  2A lt 3B) the lungs will try to restore balance
  by
• Hypoventilating
• h CO2
• i pH
• 3A lt 4B ? 4A 4B

7
Learning Tip

• Respiratory Lungs CO2 Acid
• Metabolic Kidneys HCO3 Base

8
Practice Questions

• HCO3- 45
• HCO3- 24
• PaCO2 60
• HCO3- 18
• PaCO2 20

• h alkalosis
• Normal
• h acidosis
• i acidosis
• i alkalosis

9
Practice Questions

• HCO3- 32
• PaCO2 40
• HCO3- 12
• PaCO2 53
• PaCO2 24

• h ? Alkaline
• N ? Homeostasis
• i ? Acidosis
• h ? Acidosis
• i ? Alkalosis

10
More practice questions

• PaCO2 65
• PaCO2 35
• PaCO2 52
• PaCO2 20
• HCO3 18
• HCO3 24
• HCO3 30
• HCO3 12

• h Acidosis
• Normal
• h Acidosis
• i Alkalosis
• i Acidosis
• Normal
• h Alkalosis
• i Acidosis

11
Respiratory AcidosisCharacteristics

• pH
• lt 7.35 i
• PaCO2
• gt 45 mmHg
• Hypercapnia
• Metabolic Compensation
• h HCO3-
• Kidneys reabsorb and retain HCO3

12
Respiratory AcidosisClinical Manifestations

• Feeling of fullness in the head
• h pulse and BP
• Mental cloudiness
• Weakness

13
Respiratory AcidosisEtiology

• Always d/t inadequate excretion of CO2
• Hypoventilation
• Pulmonary edema
• Aspiration
• Atelectasis
• Overdose of sedatives

14
Respiratory AcidosisManagement

• Improve ventilation
• Bronchodilators, antibiotics, pulmonary hygiene
  measures

15
Metabolic AlkalosisCharacteristics

• pH
• gt 7.45 h
• Bicarbonate / HCO3-
• gt 26 mEq/l h
• Respiratory compensation
• h CO2 by
• Hypoventilation

16
Metabolic AlkalosisClinical Manifestations

• i Ca
• Tingling of the fingers
• Hypertonic muscles
• Atrial tachycardia
• Tetany

17
Metabolic AlkalosisEtiology

• 1
• Vomiting or gastric suction
• Long term diuretics

18
Metabolic AlkalosisManagement

• Reverse underlying disorder
• Restore normal fluid electrolytes

19
Respiratory AlkalosisCharacteristics

• pH
• gt 7.45 h
• PaCO2
• lt 35 mmHg i
• Metabolic Compensation
• I HCO3 by
• The kidney will excrete HCO3

20
Respiratory AlkalosisClinical Manifestations

• Lightheadedness
• i concentration
• i LOC