Neuro-Ox 2018: Assessment of Cerebral Oxygenation Under Three Clinically Relevant Conditions

Neuro-Ox 2018: Assessment of Cerebral Oxygenation Under Three Clinically Relevant Conditions

This is a prospective observational study, consisting of 3 substudies carried out during elective neurosurgery under general anaesthesia. Each participant will take part in all 3 substudies. First, the capability of Near Infra Red Spectroscopy (NIRS) to measure the brain oxygenation is examined. A NIRS-electrode is placed on forehead skin, on the skull, and on dura. Secondly, a small dose of Phenylephrine is given, and the brain oxygenation is measured by a Clark-electrode and a NIRS-electrode, to see how Phenylephrine affects these measurements. In the third substudy, the brain oxygenations' (NIRS and Licox) response to an inspired oxygen fraction of 0.30 vs. 0.80 is investigated.

Inclusion Criteria:

• Adult (>18 years) patients
• Elective craniotomy

Exclusion Criteria:

• Repeat craniotomy
• Preoperative hypotension (defined as systolic blood pressure below 110 mmHg)
• Preoperative hypoxia (defined as peripheral oxygen saturation (SpO2) < 90% without oxygen supplementation before surgery)
• No negative pregnancy test for women <50 years.