Digital calculator – calculate maintenance and replacement requirements

 

This calculator is CA marked as a class 1 device. See below for regulatory information.

Please review the following information to determine whether IV fluid is needed.

Clinical assessment should be accompanied by review of fluid balance charts, NEWS chart and blood results.

No fluid likely to be required if patient is:

  • Drinking adequately
  • Receiving adequate fluid via nasogastric feed or total parenteral nutrition
  • Receiving large volumes with drug infusions

Fluid likely to be required if patient:

  • Has not been drinking for 8h or more
  • Has lost or are losing fluid
  • Unable to meet daily fluid requirement with oral/enteral intake

Definitions:

Euvolaemic (normal fluid balance)

  • Extremities are warm, blood pressure and heart rate are normal

Hypovolaemic (too little fluid)

  • Cold extremities, hypotension, tachycardia, oliguria, fluid loss, confusion

Hypervolaemic (too much fluid)

  • Oedematous, inspiratory crackles; raised JVP, poor urine output or fluid overload

This calculator is only for use in adults. Do not use for children under 16 years - consult paediatrician or paediatric resuscitation guidelines.

Special circumstances -

Administer IV fluids with caution or seek specialist advice for patients with following conditions:

  • Frail elderly: be cautious giving fluids to frail elderly, consult senior for advice
  • Cardiac failure: be cautious giving fluids to patients with cardiac failure, consult senior for advice
  • Diabetes: refer to local guidance for management of diabetic ketoacidosis/hyperosmolar hyperglycaemic state and variable rate intravenous insulin infusion
  • Head injury: avoid fluids containing glucose
  • Renal and hepatic failure: consult senior doctor
  • Obstetrics: consult senior for complex cases
  • Burns: consult specific guidelines and seek advice

What type of fluid does your patient require?

Replacement: Patient has ongoing abnormal fluid or electrolyte losses - e.g. due to vomiting, diarrhoea, fistulae, drain output, bile leaks, high stoma output.

Maintenance: Unable to meet daily fluid requirement with oral/enteral intake OR Not drinking for 8 hours or more.

Resuscitation: Patient is hypovolaemic - e.g. due to dehydration, blood loss or sepsis.