Warning

Audience

  • Highland HSCP only
  • Secondary Care only
    • Including: General adult wards
    • Excluding: Critical Care areas (ICU, HDU). Discuss with Registrar or above first. 
    • Excluding: Women who are pregnant
  • Adults only

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

Patients with serum K less than 2.9mmol/L: refer to NHS Highland Hypokalaemia (Guidelines)

Patients with serum Na less than 130mmol/L: refer to NHS Highland Hyponatraemia (Guidelines)

Patients with hypernatraemia: discuss with senior clinician

For fluid replacement, resuscitation and maintenance (excluding circumstances listed above) NHS Highland recommends following the Scottish IV fluids prescribing calculator and guidance.

This calculator is to support clinicians in the safe prescribing and intravenous administration of IV fluids for adult hospital inpatients, aged sixteen and over. It is to mitigate risks of clinical error in prescribing of IV fluids and consequent harm to patients.

The calculator uses patient parameters (weight, presence of frailty, potassium and sodium values, source and volume of previous 24h losses, anticipated 24h fluid intake) to calculate the volume and rate of administration of IV fluid. Based on the sources of 24h losses it will prompt the user to select an IV fluid.

Commonly available IV fluids in NHS Highland are: 

  • Crystalloids for replacement or resuscitation:
    • Hartmann's or Plasma-lyte
  • Crystalloids for maintenance: 
    • Sodium chloride 0.18%/ Glucose 4%/ Potassium chloride 0.15% (20mmol K in 1 Litre)
    • Sodium chloride 0.18%/ Glucose 4% / Potassium chloride 0.3% (40mmol K in 1 Litre)
    • Maintelyte: also contains glucose and 20mmol K in 1 Litre 
  • OR 0.9% sodium chloride.

See table below for composition and examples. 

The calculator is is based on the NICE CG174: Intravenous fluid therapy in adults in hospital | Guidance | NICE 

To access the calculator click on the link or use the QR code below:

  • Fluid balance charts can be ordered via PECOS (Code:WRT119)
  • Fluid prescription chart can be ordered via PECOS (Code: WRT007)

Aseptic No Touch Technique is to be used.

Fluid composition

For comparison, the composition of some fluids are given below and can be seen at: Composition of commonly used crystalloids table-191662813 (nice.org.uk)

Fluid for replacement or resuscitation
Electrolyte content per Litre

Plasma-lyte 148
Solution for infusion

Hartmann's solution
Compound sodium lactate BP

Na+ 140mmol
K+ 5mmol
Mg2+ 1.5mmol
Cl- 98mmol
CH3COO- (Acetate) 27mmol
C6H11O7- (Gluconate) 23mmol

Na+ 131mmol
K+ 5mmol
Ca2+ 2mmol
HCO3- (Bicarbonate) 29mmol
Cl- 111mmol

Maintenance fluid
Electrolyte content per Litre

Maintelyte
Solution for infusion
NaCl 0.18%/ Glucose 4%/ KCl 0.15%
Solution for infusion BP

NaCl 0.18%/ Glucose 4%/ KCl 0.3%
Solution for infusion BP

NaCl 0.9%

Na+ 40mmol
K+ 20mmol
Mg2+ 1.5mmol
CH3COO- (Acetate) 23mmol
Cl- 40mmol

NB: Contains glucose

Na+ 30mmol
K+ 20mmol
Cl- 50mmol

NB: Contains glucose

Na+ 30mmol
K+ 40mmol
Cl- 70mmol

NB: Contains glucose

Na+ 154mmol
Cl- 154mmol

Editorial Information

Last reviewed: 02/04/2025

Next review date: 01/04/2026

Author(s): Renal Department.

Version: 1

Approved By: Acute Services Clinical Validation Group

Reviewer name(s): Dr S Lambie, Consultant Nephrologist, S Sutherland, Clinical Educator, Surgical & Anaesthetics.

Document Id: TAM542