Endocrine Abstracts

Background: Hyponatraemia is known to be associated with significantly increased mortality in hospitalised patients. We identified the number of cases of hyponatraemia referred for an endocrine opinion in our hospital, examined the causes present, and assessed how the speed of referral to endocrinology could affect the management.

Methods: Inpatient referrals were audited over a 6-month period from 1st October 2021 to 30th April 2022. Data regarding the condition being referred, time taken to refer, and initial blood test investigations were obtained using the Cerner electronic patient database.

Results: Over the 6-month period, there were 103 referrals (64 female, 39 male, age range 22 to 95 years; mean age 73 years) with hyponatraemia. Of these, 34 were severe cases (sodium less than 125 mmol/l), 47 were moderate cases (sodium 125-129 mmol/l) and 22 were mild cases (sodium 130-135 mmol/l). 49 cases were due to hypervolaemic hyponatraemia, 33 cases were euvolaemic hyponatraemia due to the Syndrome of Inappropriate ADH (SIADH) secretion, and 21 were due to hypovolaemic hyponatraemia. 44% of referrals were sent within 48 hrs of the condition being identified, and 56% over 48 hrs. Appropriate initial investigations had been completed (paired serum and urine osmolality, 9am cortisol and thyroid function tests) in 46% of cases referred. 72% of patients referred for an endocrine review within 48 hrs had a gradual improvement in sodium within 72 hours, compared to 43% of patients referred more than 48 hrs after identifying hyponatraemia.

Conclusion: The early identification of hyponatraemia and early referral for an endocrine opinion increases the probability of hyponatraemia improving within 72 hours. We will provide education to our junior doctors during a quality improvement project to emphasise the importance of referring severe hyponatraemia to endocrinology in a timely manner, with appropriate initial investigations to enable earlier treatment.