Acid-Base Disorders & ABG's (Exam II) Flashcards
What is the excessive production of H⁺ in relation to hydroxyl ions?
Acidemia (Acidosis)
Excessive production of OH- in relation to H⁺ is known as ________.
Alkalemia (alkalosis)
What ion is used to measure pH?
H⁺
Where does HCO₃⁻ enter and leave the body?
Proximal tubule of the kidneys
Where are H⁺ reabsorbed in the kidney?
Distal tubule and collecting duct
What is the name of the acid-base balance equation?
Henderson-Hasselbalch Equation
If both PaCO₂ and HCO₃⁻ increase at the same time, then you have what?
Primary disorder with secondary compensation.
If PaCO₂ decreases and HCO₃⁻ increases at the same time, then you have what?
A mixed acid/base disorder
If the PaO₂ is is 60 at room air, what would the PaO₂ be with an FiO₂ of 80%?
PaO₂ ≈ 240 mmHg at an FiO₂ of 80%
A patients ABG is drawn and shows the PaO₂ to be 120 mmHg on an FiO₂ of 60%. What would the CRNA anticipate the patient’s PaO₂ to be on room air?
PaO₂ ≈ 40 mmHg on room air
What are the cardiovascular consequences of acidosis?
- ↓ contractility
- ↓ arterial BP
- Re-entry dysrhythmias
- Lower threshold for v-fib
- Less responsive to catecholamines.
What cardiovascular consequence occurs at a pH of 7.2?
Impaired contractility
What cardiovascular consequence occurs at a pH of 7.2?
Impaired contractility
What cardiovascular consequence occurs at a pH of 7.1?
Decreased responsiveness to catecholamines
What are the consequences of acidosis on the nervous system?
Obtundation & Coma
What are the consequences of acidosis on the pulmonary system?
- Hyperventilation
- Dyspnea
- Respiratory muscle fatigue
What are the consequences of acidosis on body metabolism?
- Hyperkalemia
- Insulin resistance
- Anaerobic glycolysis inhibition
How is respiratory acidosis defined?
- An acute decrease in alveolar ventilation results in increased PaCO₂.
- pH < 7.35
- Essentially respiratory failure
What are the three umbrella causes of respiratory acidosis?
- Central ventilation control
- Peripheral ventilation control
- VQ mismatch
What are the more granular causes of respiratory acidosis?
- Drug-induced resp depression
- Permissive hypercapnia
- Upper airway obstruction
- Status asthmaticus
- Restriction of ventilation (flail chest, rib fracture)
- Neuromuscular dysfunction
- MH
- Pneumonia/ edema / pleural effusion
In acute hypercarbia, how much will plasma HCO₃⁻ increase for every 10 mmHg increase in PaCO₂ ?
↑ HCO₃⁻ by 1 mmol/L (1mEq/L) for every 10 mmHg of PaCO₂
An acutely hypercarbic patients PaCO₂ is noted to be 70 mmHg. What would the CRNA anticipate the HCO₃⁻ to be?
3 mmol/L ( or 3 mEq/L) higher than normal
How much will plasma HCO₃⁻ compensate in the chronically hypercarbic patient?
3 mEq/L for every 10 mmHg in the PaCO₂
A chronically hypercarbic patient has a PaCO₂ of 60mmHg. What would the CRNA anticipate the HCO₃⁻ to be?
6 mEq/L higher than normal ( normal range is 22 - 26 so 28 - 32 expected)