This study evaluates whether the use of warmed solutions during cerebral angiography reduces the incidence of post-anaesthetic shivering. Half of participants will receive pre-warmed (39ºC) isotonic saline, while the other half receives the same solution at room temperature.

Shivering is a physiologic reaction aimed at raising body temperature that is very common amongst patients undergoing cerebral angiographies. The use of pre-warmed solutions during the procedure may reduce the incidence of shivering amongst these patients. In this triple-blind randomised trial, a consecutive sample of participants receiving total intravenous anaesthesia (TIVA) and undergoing cerebral angiography will be allocated to receive a warmed (39ºC) solution of up to 500cc of isotonic saline or the same solution, but at room temperature. Patients requiring sedation, those expected to require mechanical ventilation after the procedure, those with diminished consciousness (Glasgow Coma Scale <15 pts) and patients not wishing to participate will be excluded from the study. The primary endpoint for this study is the incidence of shivering up to 60 minutes after the procedure is completed. Shivering will be assessed using a validated scale by operators unaware of treament allocation. All analyses will be undertaken by a statistician that will not participate of the clinical assessment of included patients.

Inclusion Criteria:

• Patients receiving TIVA
• Patients undergoing cerebral angiography

Exclusion Criteria:

• Glasgow Coma Scale <15 points prior to procedure
• Expected need of mechanical ventilation after procedure completion
• Use of sedatives
• Refusal to participate