Fluid & Electrolytes study questions

Question 1

How do you assess fluid status in children?

Answer 1

• daily weight is most reliable (1kg=1L)
• strict I/O
• skin turgor, mucous membranes, fontanelle tension, cap refill, BP

Question 2

mild dehydration

Answer 2

• up to 5% BW loss
• subtle, normal behavior, possibly dry mucous membrane, slight decrease in urinary output

Question 3

moderate dehydration

Answer 3

• 6-9% BW loss
• lethargic, ↓ skin turgor, dry mucosa, ↓ urine (dark), sunken eyes/fontanelles

Question 4

severe dehydration

Answer 4

• ≥10% BW loss
• very irritable or lethargic, tachycardia, tachypnea, minimal/no U/O, hypotension

Question 5

isotonic dehydration

Answer 5

• Equal water and Na⁺ loss—most common type
• Serum Na⁺ normal
• no major fluid shift

Question 6

hypotonic dehydration

Answer 6

• More Na⁺ loss than water
• Serum Na⁺ ↓
• ECF → ICF; worsens ECF dehydration

Question 7

hypertonic dehydration

Answer 7

• More water loss than Na⁺
• Na⁺ ↑
• ICF → ECF; s/s appear late

Question 8

4-2-1 method

Answer 8

First 10 kg → 4 mL/kg/hr

Next 10 kg → 2 mL/kg/hr

Every kg over 20 → 1 mL/kg/hr

Question 9

fluid bolus

Answer 9

20 mL/kg of Normal Saline (NS) or Lactated Ringer’s (LR)

Given over 30–60 minutes

Avoid or limit in patients with renal or cardiac concerns​

Question 10

Respiratory Acidosis

Answer 10

• CO₂ retention (e.g., asthma, respiratory failure)
• Compensates by kidneys retain HCO₃

Question 11

Respiratory Alkalosis

Answer 11

• ↓ CO₂ from hyperventilation, fever, anxiety
• Compensates by kidneys excrete HCO₃

Question 12

Metabolic Acidosis

Answer 12

• DKA, GI losses (↓ HCO₃)
• Compensates by ↑ respiratory rate (Kussmaul)

Question 13

Metabolic Alkalosis

Answer 13

• Vomiting, NG suction (↑ HCO₃ or ↓ acid)
• Compensates by ↓ Respiratory rate/depth

Question 14

Normal ABG values

Answer 14

pH: 7.35–7.45

PaCO₂: 35–45 mmHg

HCO₃⁻: 22–26 mEq/L