So far, only one study, primarily looking at copeptin as predictive marker in postoperative AVP deficiency, also investigated in subgroup analysis copeptin in the few (12 out of 205 patients in the cohort) patients with postoperative SIAD, showing that copeptin was unhelpful in discriminating isolated SIAD and an uneventful postoperative course.10 Here, AVP is linked to neurohypophyseal diabetes insipidus.