Fluid balance

Question 1

Safe fluid prescribing algorithm

Answer 1

1. Is the patient euvolaemic, hypovolaemic or hypervolaemic?
2. Does the patient need IV fluid therapy?
3. Why does the patient need IV fluid therapy?
4. How much IV fluid does the patient need?
5. What type of IV fluid does the patient need?

Question 2

Clinical features of hypovolaemia

Answer 2

• Thirst
• Dry mucous membranes
• Reduced skin turgor
• Oligouria
• Cool peripheries
• Tachyponoea
• Tachycardia
• Hypotension
• Prolonged CRT
• Visible fluid loss (eg drains)

Question 3

Clinical features of euvelaemia

Answer 3

• Moist mucus membranes
• Warm peripheries
• Normal urine output
• Normal RR, HR, BP, CRT

Question 4

Clinical features of hypervolaemia

Answer 4

• Raised JVP
• Peripheral oedema
• Tachypneoa/Tachycardia
• Normal BP, normal CRT
• Inspirations crackles - pulmonary oedema

Question 5

What is oligouria?

Answer 5

Urine output <0.5ml/kg/hour

Question 6

Causes of oligouria

Answer 6

• Hypovolaemia
• Intrinsic kidney disease
• Cardiovascular disease
• Physiological stress response

Question 7

Routes of fluid delivery

Answer 7

• Oral: drinking adequately
• Enteral: NG, NJ
• Parenteral: IV fluids, IV medications, TPN

Question 8

When are maintainance fluids used?

Answer 8

• Indicated in patients who cannot meet their daily fluid requirements by oral intake
• Must not have excess losses
• Should be started in anyone having to fast for more than 6 hours (remember that clear fluids can be given up to 2 hours before any procedure and are preferred to IV fluids)

Question 9

Maintainance fluid requirement

Answer 9

30ml/kg/24 hours

20-25ml/Khan/24 hours in elderly, renal impairment, cardiac failure or malnourished

Question 10

Sodium, potassium and calorie requirements

Answer 10

Sodium: 1 mmol/kg/24 hours

Potassium: 1 mmol/kg/24 hours

Calories: 50-100g/24 hours to prevent starvation ketosis

Question 11

Maximum rate of IV maintainance fluids

Answer 11

100 ml/hour

Question 12

What is the standard maintainance fluid in NHS Grampian?

What fluid would you give if the patient is hyponatraemic?

What fluid would you give if the patient was hyperkalaemic?

Answer 12

0.18% NaCl / 4% glucose / 40mmol KCl

If Na < 132mmol/L use Plasmolyte 148

If K > 5 mmol/L do not give extra

Question 13

How do you determine the amount of replacement fluids?

Answer 13

• Determined based on estimated losses
• Urine does not need to be replaced unless excessive
• Given in addition to maintainance fluids

Question 14

What is the standard replacement fluid in NHS Grampian?

What replacement fluid is given for upper GI loss?

Answer 14

Plasmolyte 148

0.9% NaCl / added KCl

Question 15

Describe the fluid challenge algorithm (resuscitation fluids)

Answer 15

250-500ml Plasmolyte 148 boluses stat to a maximum of 2000ml