Renal Physl 19 Flashcards
What pH can be fatal?
pH below 7 or greater than 7.7
What can pH disturbances be classified by?
- The direction (acidosis/alkalosis)
* Cause (metabolic/respiratory)
When is a disturbance considered metabolic?
If the change in pH is due to acids or bases that are not derived from carbon dioxide
When is a disturbance considered respiratory?
When a change in carbon dioxide is induced by hypo or hyperventilation
What does it mean if a change is plasma pH is detected what does this mean about the lines of defense?
The buffer system has failed leaving respiratory or renal compensation
What is the only option if the problem is respiratory in origin?
The kidneys are the only option for homeostatic compensation
What can contribute to putting pH back to normal if the root problem is metabolic?
Both respiratory and renal mechanisms
When does respiratory acidosis happens?
Hypoventilation increases carbon dioxide accumulation or drugs effects, airway resistance, impaired alveolar gas exchange, muscular dystrophy COPD
What does COPD lead to?
Increased plasma carbon dioxide which leads to increased hydrogen and bicarbonate ion
What are the effects of respiratory acidosis on pH and bicarbonate?
pH decreases by bicarbonate levels increase
What type of compensation is used for respiratory acidosis?
Renal compensation
What is the renal compensation for respiratory acidosis?
Hydrogen is excreted and bicarbonate is reabsorbed
What causes Metabolic acidosis?
Dietary and metabolic input of hydrogen ion exceeds excretion
What are some causes of Metabolic Acidosis?
- Lactic acidosis
- Ketoacidosis
- Ethylene glycol
- Loss of bicarbonate
How are hydrogen ions and the equation affected by metabolic acidosis?
Hydrogen ions increases and shifts the equilibrium to the left increasing carbon dioxide and depleting the bicarbonate buffer
What is another condition that can cause metabolic acidosis?
Bicarbonate being lost after diarrhea
What is an important distinction in metabolic acidosis from respiratory acidosis?
The reduced bicarbonate concentration in metabolic acidosis
What is a common sign of metabolic acidosis?
Hyperventilation
What is seen in renal compensation in metabolic acidosis?
Hydrogen ions are excreted and bicarbonate is reabsorbed
What does respiratory alkalosis a occur as a result of?
Hyperventilation because carbon dioxide levels fall
How does respiratory alkalosis affect the equation?
Shifts it to the left so plasma hydrogen and bicarbonate decrease
Why does breathing into a bag help with respiratory alkalosis?
Because of rebreathing of carbon dioxide that was exhaled
What is the only compensation for respiratory alkalosis?
Renal compensation
What renal compensation is seen is respiratory alkalosis?
Filtered bicarbonate is not reabsorbed in the proximal tubule and is actively secreted
