Background

• Patient with hyponatremia ~129mmol/l chronically over years

Discussion

• What is cutoff to proceed with surgery?
  • Suggested cutoff around 125
  • https://www.bjaed.org/action/showPdf?pii=S2058-5349%2817%2930134-8
  • Symptoms are usually non-specific e.g. vomiting headaches, diarrhoea, cramps and are uncommon at levels above 125mmol/L
  • Severe hyponatraemia <120mmol/l can precipitate seizures and death
  • Perioperative hyponatraemia is associated with increased 30-day perioperative morbidity and mortality. 
    • This risk is further increased in non-emergency surgery and ASA 1&2 patients
    • See Arch Intern Med. 2012;172(19):1474-1481. doi:10.1001/archinternmed.2012.3992
• Management is dependent on underlying cause:
  • https://aci.health.nsw.gov.au/networks/eci/clinical/clinical-tools/electrolytes/sodium-hyponatraemia

Plan

• Await plasma and urinary sodium and osmolality
• Follow up with endocrinology