Ion imbalance

Question 1

What is the most abundant extracellular cation?

Answer 1

Na+

Question 2

What is the most abundant extracellular anion?

Answer 2

Cl-

Question 3

What is the most abundant intracellular ion?

Answer 3

K+

Question 4

What is hypokalemia?

Answer 4

Low potassium in the blood (K+ < 3.5 mmol/L)

Question 5

What are the symptoms of hypokalemia? (3 [6])

Answer 5

• SM: constipation
• SkM: weakness/ flaccid paralysis, cramps, resp depression)
• Cardiac: arrhythmias, arrest

Question 6

How would you investigate hypokalemia? (2)

Answer 6

• U&E: K+ < 3.5 mmol/L

- ECG: U waves, no T, long PR and long QT

Question 7

How would you treat hypokalemia? (2)

Answer 7

Mild: oral K+
Severe: IV K+

Question 8

What is hyperkalemia?

Answer 8

High potassium in the blood (K+ > 5.5 mmol/L)

Question 9

What are the symptoms of hyperkalemia? (3 [4])

Answer 9

• SM: cramping
• SkM: weakness/ flaccid paralysis
• Cardiac: arrhythmias, arrest

Question 10

How would you investigate hyperkalemia? (2)

Answer 10

• U&E: K+ > 5.5 mmol/L

- ECG: tall tented T waves, ST depression, small P

Question 11

How would you treat hyperkalemia? (4)

Answer 11

Non-urgent: polystyrene sulfonamide resin

Urgent: calcium gluconate; insulin; resins that bind K+

Question 12

A pt’s ECG shows prolonged QT, inverted T wave and the presence of a U wave. What is this suggestive of?

Answer 12

Hypokalemia

Question 13

A pt’s ECG shows tall tented T waves, small P wave and ST depression. What is this suggestive of?

Answer 13

Hyperkalemia

Question 14

A pt’s ECG shows tall tented T waves, ST depression a wide QRS, prolonged PR interval and absent P waves. What is this suggestive of?

Answer 14

Severe hyperkalemia

Question 15

How is calcium balance controlled in the body? (2)

Answer 15

Parathyroid: PTH
Thyroid: Calcitonin

Question 16

How is the majority of Ca2+ stored in the body?

Answer 16

In the bone as calcium phosphate

Question 17

What is hypercalcemia?

Answer 17

High calcium in the blood

Question 18

What causes hypercalcemia? (2)

Answer 18

• Primary hyperparathyroidism

- Cancer

Question 19

What are the symptoms of hypercalcaemia? (5)

Answer 19

• Painful BONES: fractures, osteoporosis
• Kidney STONES
• Abdominal GROANS: constipation, N+V, indigestion
• Psychiatric MOANS: lethargy/ fatigue, depression, confusion
• THRONES: polydipsia, polyuria

Question 20

How would you investigate hypercalcemia? (3)

Answer 20

• U&E: Ca2+ > 10.5 mg/dL
• ECG: short QT interval, bradycardia, AV block
• Lab tests: parathyroid, vit D

Question 21

How would you treat hypercalcemia? (3)

Answer 21

• Fluids: NaCl saline
• Furosemide (loop diuretics)
• Bisphosphonates (prevent bone resorption)

Question 22

What is hypocalcemia?

Answer 22

Low blood calcium

Question 23

What causes hypocalcemia? (5)

Answer 23

HAVOC
Hypoparathyroidism
Acute pancreatitis
Vit D deficiency
Osteomalacia
CKD

Question 24

What are the symptoms of hypercalcemia? (6)

Answer 24

SPASM C
Spasms
Peripheral paraesthesia
Anxious
Seizures
Muscle tone increase
Cataracts

Question 25

What are the signs of hypocalcemia? (2)

Answer 25

• Chvostek’s sign: tapping on the facial nerve causes facial muscle twitch
• Trousseau’s sign: inflation of bp cuff causes flexion of wrist + fingers

Question 26

How would you investigate hypocalcemia? (3)

Answer 26

• U&E: Ca2+ < 8.5 mg/dL
• ECG: long QT interval
• Lab test: parathyroid, vit D

Question 27

How would you treat hypocalcemia? (2)

Answer 27

Mild: Adcal
Severe: calcium gluconate