Fluid management

Question 1

Why are IV fluids prescribed?

Answer 1

• Shock: 45^o passive leg raise fluid responsiveness
  
  • Resuscitation
• No shock + unable to meet fluid/electrolyte needs
  
  • Maintenance
  • Replacement and redistribution if
    
    • Complex fluid replacement
    • Complex electrolyte replacement
    • Abnormal distribution issues

Question 2

What considerations should be made when prescribing fluids?

Answer 2

• Aim of the fluid
• Weight and size of patient
• Patient co-morbidities: ^eg. CKD; HF
• Reason for admission
• Electrolytes

Question 3

State the contents of 0.9% sodium chloride

Answer 3

• Na⁺: 150 mmol/L
• Cl^-: 150 mmol/L

Question 4

State the contents of 5% dextrose

Answer 4

Glucose: 50 g/L

Question 5

State the contents of Hartmann’s

Answer 5

• Na⁺: 131 mmol/L
• K⁺: 5 mmol/L
• HCO₃^-: 29 mmol/L
• Cl^-: 111 mmol/L
• Ca²⁺: 2 mmol/L

Question 6

Why is 0.9% saline ideal for fluid resus and maintenence?

Answer 6

• It quickly equilibriates across the ECF
• Distributes across ICF slower than dextrose

Question 7

Why is 5% dextrose appropriate for fluid maintenence?

Answer 7

It quickly distributes across all fluid compartments.

Question 8

What is the benefit of using Hartmann’s solution?

Answer 8

• It provides some potassium in addition to fluid
• Very similar to normal plasma values of electrolytes

Question 9

State the normal daily fluid and electrolyte requirements for maintenance IV fluids

Answer 9

• Water: 25-30 ml/kg/d
• Na⁺, K⁺ and Cl^-: 1 mmol/kg/d
• Glucose: 50-100 g/d

Question 10

What is important to remember regarding IV K⁺ replacement?

Answer 10

• Peripheral IV K⁺ rate should not >40 mmol/L
  
  • Higher rates require specialist input
• Available in separate 20 and 40 mmol IV bags
  
  • Round weight-adjusted K⁺ to closest 20 mmol
• Do not add K⁺ to IV fluid bads

Question 11

List four signs of mild-moderate dehydration

Answer 11

• Dry mucous membranes
• Dizziness; Fatigue
• Reduced skin turgor
• Postural hypotension
• Slow capillary refill
• Oligouria

Question 12

List 3 signs of severe dehydration

Answer 12

• Weakness
• Hypotension; tachycardia
• Anuria
• Confusion;Coma

Question 13

List four signs of mild-moderate fluid overload

Answer 13

• Raised JVP
• Peripheral oedema
• Pulmonary oedema
  
  • Pink frothy sputum
  • Cardiac wheeze
  • Basal crepitus

Question 14

List two signs of severe fluid overload

Answer 14

• Tachycardia
• Tachypnoea; dyspnoea
• Cyanosis