During the course of their acute illness patients with subarachnoid hemorrhage and severe
traumatic brain injury often develop disturbances in their fluid balance and electrolyte
homeostasis. These shifts are associated with worse outcome and increased morbidity.
The aim of this observational study is to systematically analyze the incidence,
characteristics, potential diagnostic markers and predisposing factors of such disturbances.
The investigators hypothesize that many disturbances cannot be classified with a standard
diagnostic approach and that variable fluid management contributes to their pathophysiology.
Patients will be closely monitored clinically and the exact fluid and electrolyte balances
will be recorded. Treatment decisions are within the bedside physicians responsibility.
Baseline fluid management is standardised. No interventions are planned. The observation
period equal the duration of ICU stay.