Metabolic Alkalosis (more in depth)

Question 1

What is the most common cause of metabolic alkalosis?

Answer 1

HCl loss

This is often due to vomiting.

Question 2

Provide a list of causes of metabolic alkalosis

Answer 2

Those with hypercalcaemia (bones/stones/abdo moans/psych overtones):
MIlk-alkali syndrome
Primary hyperparathyroidism
Metastatic cancer

Those without normocalcaemia:
Cushings
Mineralocorticoid excess (can cause HYPERcalcaemia)

Decreased:
Loop diuretics e.g. Furosemide (NB it is used to treat HYPERcalcaemia)
Barterrs - low Ca/Cl/K

Question 3

Name a drug that can induce metabolic alkalosis.

Answer 3

Diuretics (especially frusemide)

Other drugs may include laxatives.

Question 4

What syndrome is associated with metabolic alkalosis due to excessive calcium intake?

Answer 4

Milk-alkali syndrome

This syndrome involves the triad of hypercalcemia, metabolic alkalosis, and renal failure.

Question 5

What IV medication can lead to metabolic alkalosis?

Answer 5

NaHCO3 therapy

Sodium bicarbonate therapy can increase bicarbonate levels in the blood.

Question 6

Which endocrine disorders can cause metabolic alkalosis?

Answer 6

Mineralocorticoid or glucocorticoid excess

Conditions such as Cushing’s syndrome can lead to these hormonal imbalances.
Conn’s syndrome.

Question 7

What is Barter’s syndrome?

Answer 7

Bartter syndrome is an autosomal recessive disorder Na/K/Cl cotransporter resulting in loss of K,Cl, mag and calcium with increasing intravascular HCO3 causing metabolic alkalosis.
A similar syndrome can be caused by aminoglycoside use

Question 8

True or False: Laxative abuse can lead to metabolic alkalosis.

Answer 8

True

Question 9

What is the significance of urine chloride levels less than 10 mmol?

Answer 9

Often associated with volume depletion and increased proximal tubular reabsorption of HCO3

These levels typically respond to saline infusion, which replaces chloride and volume. Common causes include previous diuretic therapy and vomiting.

Question 10

What are the implications of urine chloride levels greater than 20 mmol?

Answer 10

Often associated with volume expansion and hypokalaemia; resistant to saline infusion

Causes include excess aldosterone, severe K+ deficiency, current diuretic therapy, and Bartter’s syndrome. A high urinary chloride with hypokalemia suggests mineralocorticoid excess.

Question 11

What does a high urinary chloride in association with hypokalemia suggest?

Answer 11

Mineralocorticoid excess

This finding can indicate underlying issues with adrenal hormone regulation.

Question 12

What can the urinary chloride/creatinine ratio indicate?

Answer 12

It may be elevated if there is an extra-renal cause of alkalosis

This ratio can sometimes be a useful diagnostic tool.

Question 13

Fill in the blank: Urine CI- levels greater than 20 mmol are often associated with _______.

Answer 13

Volume expansion and hypokalaemia

Question 14

True or False: Urine chloride levels less than 10 mmol are resistant to therapy with saline infusion.

Answer 14

False

Levels less than 10 mmol typically respond to saline infusion.

Question 15

What are common causes of urine chloride levels less than 10 mmol?

Answer 15

• Previous diuretic therapy
• Vomiting

Question 16

What are common causes of urine chloride levels greater than 20 mmol?

Answer 16

• Excess aldosterone
• Severe K+ deficiency
• Current diuretic therapy
• Bartter’s syndrome

Question 17

What is the significance of urine chloride levels less than 10 mmol?

Answer 17

Often associated with volume depletion and increased proximal tubular reabsorption of HCO3

These levels typically respond to saline infusion, which replaces chloride and volume. Common causes include previous diuretic therapy and vomiting.

Question 18

What are the implications of urine chloride levels greater than 20 mmol?

Answer 18

Often associated with volume expansion and hypokalaemia; resistant to saline infusion

Causes include excess aldosterone, severe K+ deficiency, current diuretic therapy, and Bartter’s syndrome. A high urinary chloride with hypokalemia suggests mineralocorticoid excess.

Question 19

What does a high urinary chloride in association with hypokalemia suggest?

Answer 19

Mineralocorticoid excess

This finding can indicate underlying issues with adrenal hormone regulation.

Question 20

What can the urinary chloride/creatinine ratio indicate?

Answer 20

It may be elevated if there is an extra-renal cause of alkalosis

This ratio can sometimes be a useful diagnostic tool.

Question 21

Fill in the blank: Urine CI- levels greater than 20 mmol are often associated with _______.

Answer 21

Volume expansion and hypokalaemia

Question 22

True or False: Urine chloride levels less than 10 mmol are resistant to therapy with saline infusion.

Answer 22

False

Levels less than 10 mmol typically respond to saline infusion.

Question 23

What are common causes of urine chloride levels less than 10 mmol?

Answer 23

• Previous diuretic therapy
• Vomiting

Question 24

What are common causes of urine chloride levels greater than 20 mmol?

Answer 24

• Excess aldosterone
• Severe K+ deficiency
• Current diuretic therapy
• Bartter’s syndrome