Bay Navigator

Pre-Operative Pathways
Pre-Operative Hyponatraemia


This pathway demonstrates the approach to hyponatraemia if detected at preassessment. The preassessment team will give the patient a letter to present to their GP indicating that hyponatraemia is present and further action is required. The patient will be contacted by preassessment six months later, and if no further action has been taken it is possible that their elective operation will be cancelled.

Pre-Operative Hyponatraemia Definition

  • Sodium < 132mmol/L
  • Procedure on hold
  • Pre-Operative optimisation required


  1. Optimise if possible in general practice
  2. If Sodium ≥ 132mmol/L
    • Patient to notify Pre-Assessment Clinic
      • On completion of investigations and treatment, please ask the patient to notify the Pre-Assessment Clinic (PAC).
      • The contact details are on their letter from PAC. The telephone number is 07 579 8260 or email address is
  3. If Sodium < 132mmol/L
    • Consider investigation & discuss with a physician
      • Lower sodium levels will be accepted if chronically low, investigated and discussed with a physician.
    • GP to notify Pre-Assessment Clinic
      • Please send details of historic figures if chronically low, relevant investigations performed and details of specialist discussion.


Pathway developed by the following people:

Name Position

Dr Daniel Jackson

GP Liaison/Bay Navigator Lead

Dr Renee Franklin

Anaesthetist, PAC

Esther Walker

Associate Clinical Nurse Manager, PAC

Wendy Carey

Programme Manager, SIU

Helen De Vere

Programme Manager, SIU

Disclaimer: These pathways, for the care and management of patients within Bay of Plenty, have been developed jointly by primary and secondary care clinicians. They provide guidance for General Practice teams to diagnose and manage patients suffering from a number of different conditions, and contain patient information resources. The pathways are maps of publicly-funded services accessed by referral from the community, and are strongly evidence based, but are not full clinical guidelines. As the pathways are suggested guidance only, while using them you must exercise your own clinical judgement and pertinent clinical data when treating your patient. This site is intended to be flexible and frequently updated. While every effort has been made to ensure accuracy, all information should be verified.