Lung Volumes and ABGs

When does resting end expiratory pressure (REEP) occur

At the end of tidal expiration

What is A

Maximum inspiration

What is B

Maximum expiration

What is C and the volume

Inspiratory reserve volume
3000 mL

What is D and the volume

Tidal volume
500 mL

What is E and the volume

Expiratory reserve volume
1100 mL

What is F and the volume

Residual volume
1200 mL

What is G and the volume

Functional residual capacity
2300 mL

What is H and the volume

Inspiratory capacity
3500 mL

What is I and the volume

Vital capacity
4600 mL

What is J and the volume

Total lung capacity
5800 mL

What is FEV1

Forced expiratory volume in 1 second

What is the FEV1 for the healthy population

>70% of FVC exhaled within the first second
(FEV1/FVC) x 100

What is FEF

Forced expiratory flow rate
25-75%

What is external respiration

Exchange of O2 and CO2 between the lungs and the environment

What is internal respiration

Exchange of O2 and CO2 between circulating blood and body tissues

What is PaO2 related to

Oxygen saturation (SpO2) through the pulse oxyhemoglobin curve

What does a PaO2 of 55 correlated to in terms of SpO2

88%

What PaO2 level is considered hypoxemia

<80

Hypoxemia

Low level of O2 in arterial blood

Hypoxia

Low level of O2 in tissue

What does pH measure and what does it look at

Acid-base balance in the blood
Alveolar ventilation

What does it mean if the pH is normal

Compensated

What is normal pH

7.35-7.45

What is normal PaCO2

35-45

What does it mean if PaCO2 is normal

Metabolic compensated

What type of relationship does PaCO2 and pH have

Indirect relationship

What is normal HCO3-

22-26

What does it mean if HCO3- is normal

Respiratory compensated

What type of relationship does HCO3- and pH have

Direct relationship

What if all 3 (pH, PaCO2, and HCO3-) are abnormal

Partially compensated

What type is A

Respiratory acidosis

What type is B

Respiratory alkalosis

What is C

Metabolic acidosis

What is D

Metabolic alkalosis

Describe the condition for A

pH: decrease
PaCO2: increase
HCO3-: normal

Describe the condition for B

pH: increase
PaCO2: decrease
HCO3-: normal

Describe the condition for C

pH: decrease
PaCO2: normal
HCO3-: decrease

Describe the condition in D

pH: increase
PaCO2: normal
HCO3-: increase

What are the clinical manifestations for respiratory acidosis

Hypercapnia
Restlessness
Disorientation
Confusion
Sleepiness
Visual disturbances
Headache
Flushing
Dyspnea
Cyanosis
Decreased DTR
Hyperkalemia
Palpitations

What is recommended treatment for respiratory acidosis

Treat the underlying cause
Support ventilation
Correct electrolyte imbalance

What are the clinical manifestations for respiratory alkalosis

Tachypnea
Hypocapnia
Dizziness
Difficulty concentrating
N/T
Blurred vision
Diaphoresis
Dry mouth
Muscle cramps
Carpopedal spasms
Muscle twitching and weakness
Hyper reflexia
Arrhythmias
Hypokalemia
Hypocalcemia

What is the recommended treatment for respiratory alkalosis

Treat the underlying cause
Increase carbon dioxide retention (rebreathing, sedation)

What is the clinical manifestation for metabolic acidosis

Hyperventilation (compensatory)
Muscular twitching
Weakness
Malaise
Nausea
Vomiting
Diarrhea
Headache
Hyperkalemia (cardiac arrhythmias)
Coma (death)

What is the recommended treatment for metabolic acidosis

Treat underlying cause
Correct electrolyte imbalance (use NaCO3 for severe acidosis [pH < 7.2])

What is the clinical manifestation for metabolic alkalosis

Hypoventilation (compensatory)
Dysrhythmias
Nausea
Prolonged vomiting
Diarrhea
Confusion
Irritability
Agitation
Restlessness
Muscle twitching
Cramping
Hypotonia
Weakness
Trousseau sign
Paresthesias
Seizures
Coma
Hypokalemia
Hypochloremia

What is the recommended treatment for metabolic alkalosis

Treat underlying causes
Administer potassium chloride

Conditions for optimal respiration

Ventilation and perfusion are matched

Dead space condition

Well ventilated but no gas exchange occurs

Anatomical dead space

Blood and O2 are present, but vessel walls are too thick to allow for exchange

Physiological dead space

Volume of air in the respiratory zone that does participate in gas exchange

What conditions are shunts typically used for

Pneumonia
Pulmonary edema
Alveolar collapse

What receptors control ventilation

Baroreceptors
Chemoreceptors
Irritant receptors
Stretch receptors

What are the central control centers to control ventilation

Cortex
Pons
Medulla
ANS