Acid-Base Imbalances Flashcards
What is the normal bicarbonate level in arterial blood?
22 to 26 mEq/L
What is the normal range for PaCO2 in arterial blood?
35 to 45 mmHg
What is the normal PaO2 level in arterial blood?
80 to 100 mmHg
What is the normal range of SaO2?
95 to 100 %
What is the difference between PaO2 and SaO2?
1) PaO2 - Partial pressure of oxygen dissolved in arterial blood. Measured by obtaining ABGs.
2) SaO2 - Arterial oxygen saturation. Measured with O2 monitor placed on finger.
What is the ultimate effect of increased CO2 and H+ ions on cerebral blood vessels?
Eventually, CO2 and H+ ions cause cerebral blood vessels to dilate, which ⬆ blood flow to the brain. Increased blood flow can cause cerebral edema and depressed CNS activity which presents as headache, confusion, lethargy and N&V.
In acute respiratory acidosis, the pH drops below normal. In chronic respiratory acidosis, commonly due to COPD, the pH stays within normal limits. Why is this?
Because the kidneys have had time to compensate for the imbalance.
Why should the nurse administer LOWER concentrations of oxygen to patients with chronic acidosis caused by COPD and not high concentrations of oxygen?
Because the medulla of patients with COPD is accustomed to high CO2 levels and a lack of oxygen, called the hypoxic drive, stimulates those patients to breathe. Too much O2 will diminish that drive and depress respiratory efforts.
BUN is formed as a waste product when the liver breaks down protein, how does sepsis and fever cause ⬆ BUN?
Fever and Sepsis are Hypermetabolic states (increases the rate of breakdown of substances in the body). Therefore, protein is broken down at an increased rate and BUN builds up.
Which two bodily responses can cause Hyperventilation and resulting respiratory alkalosis?
1) Anxiety
2) Pain
Which 4 class of drugs can cause respiratory alkalosis?
1) Catecholamines
2) Nicotine
3) Salicylates
4) Xanthines (i.e., Aminophyllines)
During acidosis, the kidneys try to compensate by secreting excess H+ ions into the renal tubules. Which ions are exchanged or reabsorbed for the secreted H+ ions?
Sodium ions and Bicarbonate ions
What are Kussmaul’s Respirations?
Hyperventilation and increased depth of respirations associated with metabolic acidosis.
Which Acid-base imbalance can the Anion-gap be used to check for? Explain why it cannot be used to check for the other three acid-base imbalance.
The Anion gap can only be used to check for Metabolic Acidosis because the Anion gap = {(Na+P)-(Cl+HCO3)} , which yields an acidotic state if the product is over 14 anions (16 if P+ is included). The Anion Gap represents the unmeasured anions, usually ketoic acid, lactic acid, and salycilate acid.
(T/F) A low PaO2 is an indication on Lung problem.
True
