ESPE Abstracts

Background: Hyponatremia is an electrolyte disorder, that may lead to severe complications such as rhabdomyolysis, seizures, coma, and death. Clinicians do take hyponatremia seriously. However sometimes clinicians should be careful in interpreting the low laboratory sodium level as it does not necessarily reflect the actual natremic status especially when the patient is euvolemic and having normal serum osmolality, for which pseudohyponatremia should be considered. Pseudohyponatremia therefore is expected in cases of hyperlipidaemia, hyperglycaemia, and hyperproteinaemia.

Case: We are reporting a 4-year-old girl presented with 1-day history of severe, central, non-radiating abdominal pain associated with frequent vomiting, diagnosed with acute pancreatitis secondary to hypertriglyceridemia, found to have low sodium level (120 mmol/L) with normal potassium level of 4.6 mmol/L. Other investigations are tabulated. The severe hypertriglyceridemia was taken seriously. Conservative management with insulin infusion thought to be superior to plasmapheresis as it is less invasive. Therefore our patient was started on intravenous 10% dextrose mixed with 0.9% sodium chloride solution running at 1.5 times the maintenance fluid rate adjusted for her weight. Insulin infusion was started as 0.1u/Kg/hr, but as her glucose dropped causing mild hypoglycaemia, for which the insulin infusion reduced to 0.05u/kg/hr. No direct treatment intended for the hyponatremia, and it was opted out to treat the hypertriglyceridemia with close monitoring of hyponatremia as pseudohyponatremia was strongly suspected in this case. Within 24 hours of commencing her on insulin infusion, her triglycerides started drifting down leading to massive improvement and subsequently normalization of the sodium level.

Discussion: Normally, most electrolytes including sodium ion are dissociated in the water component of a plasma. When the plasma water volume significantly deviates from 93% due to high concentration of proteins or lipids in plasma, pseudohyponatremia occur. Improvement in triglycerides level means improvement in lipemic effect on blood, leading to normalisation of the sodium level. Not just that, but we have also observed an improvement of the haemoglobin level. The awareness of this condition saved the patient from receiving unnecessary fluid boluses or hypertonic sodium chloride solution.

Conclusion: Pseudohyponatremia can occur in patients with hypertriglyceridemia. Therefore, lowering the elevated triglycerides results in improvement of sodium levels.