Pulmonary Embolism in Adipsic DI: Can Desmopressin Be a Contributing Factor?

Background: Adipsic DI (ADI) is a rare disease associated with various morbidities. One of them is venous thromboembolism (VTE). In literature there are less than 10 reported cases and scarce management orientations. Classically, in ADI, VTE risk is due to dehydration and acute hypernatremia. Desmopressin should also be considered as it has a known role in blood coagulation such as increasing platelet cohesion and promoting von Willebrand factor release. Clinical Case: A 51-year woman with past medical history of obesity class 3 and a craniopharyngioma surgically intervened 8 months before, underwent a second craniotomy due to recurrent lesion. Postoperatively the patient developed an ADI, hypopituitarism and impairement of higher brain functions namely short-term memory and sleep-wake cycles impairment. She was discharged on desmopressin 0.35mg/day, levetiracetam 1500mg/day, hidrocortisone 15mg/day, levothyroxine 75mcg/day and quetiapine 25mg/day. Two weeks after discharge, the patient was admitted to the emergency room with anorexia and malaise. Tests were consistent with PE: elevated D-dimmer levels and CT angiography revealing bilateral PE. Treatment with enoxaparin was initiated. There was no hemoconcentration or polycythemia; kidney and liver function were normal, and sodium of 148 mEq/L (135-145 mEq/L). Three days before she had normal sodium levels. Respiratory insufficiency, deep vein thrombosis and infection were excluded. The patient did not present signs of dehydration. Brain CT did not show acute alterations. There was no personal history of smoking or family history of thrombosis and the patient was not on bed rest in the previous couple of weeks. During hospital stay abdominal and pelvic CT did not reveal malignancies. The patient was discharged on enoxaparin and posteriorly underwent a mammogram and colonoscopy; both exams without relevant alterations. At the last follow-up visit, she remained hypocoagulated and with desmopressin, with no further episodes of thrombosis. Conclusion: We report for the first time a case of PE in an obese patient with ADI treated with desmopressin and without overt hypernatremia or dehydration. All previously published cases of VTE in ADI have occurred in patients presenting with moderate to severe hypernatremia (sodium 157-181 mEq/L) and some degree of dehydration at the time of the event. Obesity and a recent hospitalization may have contributed to the development of VTE but desmopressin should also be taken into consideration due to its known effects on coagulation. Thromboprophylactic treatment after pituitary surgery and during acute episodes of hypernatremia and dehydration is already warranted in ADI but we additionally suggest considering at least short-term thromboprophylaxis in obese patients with recent ADI diagnosis treated with desmopressin as they might have this additional increased thrombotic risk.