Hydrocortisone versus dexamethasone in cerebral salt-wasting after aneurysmal subarachnoid hemorrhage

Cerebral salt wasting syndrome (CSW) is frequently observed in aneurysmal subarachnoid hemorrhage (SAH) patients and results in excessive natriuresis with decreased extracellular fluids, leading to hyponatremia and hypovolemia. Hyponatremia is associated with an increased complication rate and potential mortality. This study compares hydrocortisone and dexamethasone for CSW-associated hyponatremia prophylaxis after non-traumatic SAH. This retrospective cohort study analyzed data from 510 consecutive patients with non-traumatic SAH who were admitted to the University Hospital of Münster, Germany, between October 2009 and December 2019. Hyponatremia was defined as blood sodium levels <130 mmol/L. We compared 188 patients treated with dexamethasone and 322 with hydrocortisone, focusing on the incidence of hyponatremia (<130 mmol/L) and CSW, defined as sodium levels <135 mmol/L with a negative fluid balance. Hyponatremia (Na(p) <130 mmol/L) developed in 87 patients (25.0% dexamethasone, 12.4% hydrocortisone; p =0.0004). Median treatment durations were 9.0 days for dexamethasone (IQR, 5.0-15.0 days) and 10.0 days for hydrocortisone (IQR, 8.0-12.8 days). Average daily doses were 9.2 mg (± 4.3) of dexamethasone and 114.3 mg (± 81.9) of hydrocortisone. Simultaneous negative fluid balance and hyponatremia (Na(p) <135 mmol/L) occurred in 203 patients (39.8%) (47.3% dexamethasone vs. 35.4% hydrocortisone) (p= 0.0079, OR: 1.64, 95% CI: 1.14-2.37). For hyponatremia alone (Na(p) <130 mmol/L), multivariable analysis showed an OR of 0.21 (p=0.00021 , 95%CI: 0.09-0.48) between both groups, indicating a 4.8 times higher risk in the dexamethasone group. Our findings indicate that hydrocortisone is associated with a lower frequency of CSW-associated hyponatremia following non-traumatic SAH as compared to dexamethasone. • Retrospective single-center cohort of 510 non-traumatic SAH patients comparing prophylactic hydrocortisone (n=322) vs dexamethasone (n=188) for CSW-related hyponatremia. • Severe hyponatremia (Na < 130 mmol/L) occurred less frequently in patients receiving hydrocortisone compared with those receiving dexamethasone (12.4% vs 25%; adjusted OR 0.21; p ≈ 0.0002), suggesting an association between dexamethasone use and a higher likelihood (≈4.8×) of hyponatremia. • Corticosteroid administration for 9-10 days with mean daily doses of 9.21 mg of dexamethasone per day and 114.27 mg of hydrocortisone per day • CSW proxy outcome (Na<135 mmol/L plus negative daily fluid balance) was lower with hydrocortisone: 35.4% vs 47.3% (OR 1.64 favoring hydrocortisone; p=0.008). • Time‐to‐event and recurrence favored hydrocortisone: by day 7, 95% remained hyponatremia-free vs 79% on dex (p<0.0001); multiple hyponatremia episodes occurred less often (5.9% vs 14.9%; p<0.05). • Risk factors: lower baseline sodium and older age increased hyponatremia risk (p=0.004 and p=0.032); higher corticosteroid dose trended protective (p=0.058); no other confounders were significant.