Endotracheal intubation and mechanical ventilation may be used to ensure proper oxygen supply and provide a secure airway. Hypotension (low blood pressure), which has a devastating outcome in TBI, can be prevented by giving intravenous fluids to maintain a normal blood pressure. Failing to maintain blood pressure can result in inadequate blood flow to the brain. Blood pressure may be kept at an artificially high level under controlled conditions by infusion of norepinephrine or similar drugs; this helps maintain cerebral perfusion. Body temperature is carefully regulated because increased temperature raises the brain's metabolic needs, potentially depriving it of nutrients. Seizures are common. While they can be treated with benzodiazepines, these drugs are used carefully because they can depress breathing and lower blood pressure. Anti-convulsant medications have only been found to be useful for reducing the risk of an early seizure. Phenytoin and leviteracetam appear to have similar levels of effectiveness for preventing early seizures. People with TBI are more susceptible to side effects and may react adversely to some medications. During treatment monitoring continues for signs of deterioration such as a decreasing level of consciousness.