Incidence and Effect of Diabetes Insipidus in the Acute Care of Patients with Severe Traumatic Brain Injury

Background: Literature on diabetes insipidus (DI) after severe traumatic brain injury (TBI) is scarce. Some studies have reported varying frequencies of DI and have showed its association with increased mortality, suggesting it as a marker of poor outcome. This knowledge gap in the acute care consequences of DI in severe TBI patients led us to conceive this study, aimed at identifying risk factors and quantifying the effect of DI on short-term functional outcomes and mortality.

Methods: We assembled a historic cohort of adult patients with severe TBI (Glasgow Coma Scale ≤ 8) admitted to the intensive care unit (ICU) of a tertiary-care university hospital over a 6-year period. Basic demographic characteristics, clinical information, imaging findings, and laboratory results were collected. We used logistic regression models to assess potential risk factors for the development of DI, and the association of this condition with death and unfavorable functional outcomes [modified Rankin scale (mRS)] at hospital discharge.

Results: A total of 317 patients were included in the study. The frequency of DI was 14.82%, and it presented at a median of 2 days (IQR 1-3) after ICU admission. Severity according to the Abbreviated Injury Scale (AIS) score of the head, intracerebral hemorrhage, subdural hematoma, and skull base fracture was suggested as risk factors for DI. Diagnosis of DI was independently associated death (OR 4.34, CI 95% 1.92-10.11, p = 0.0005) and unfavorable outcome (modified Rankin Scale = 4-6) at discharge (OR 7.38; CI 95% 2.15-37.21, p = 0.0047).

Conclusions: Diabetes insipidus is a frequent and early complication in patients with severe TBI in the ICU and is strongly associated with increased mortality and poor short-term outcomes. We provide clinically useful risk factors that will help detect DI early to improve prognosis and therapy of patients with severe TBI.