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

Not Applicable

Completed

• Conditions: Elective Craniotomy; General Anaesthesia; Neurosurgery
• Interventions: Device: NIRS measurements on skin, skull and dura; Drug: Phenylephrine's effect on brain oxygenation; Drug: Normal vs. high inspired oxygen

• Registration Number: NCT03682198
• Lead Sponsor: University Hospital Bispebjerg and Frederiksberg

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2018-08-28
• Study First Submitted QC: 2018-09-21
• Study Start: 2018-09-24
• Study First Posted: 2018-09-24
• Primary Completion: 2020-10-01
• Study Completion: 2020-10-01
• Status Verified: 2020-11
• Last Update Submitted: 2020-11-02
• Last Update Posted: 2020-11-03

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 18

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
One strategy for all enrolled patients:	NIRS measurements on skin, skull and dura	All patients will participate in three substudies, in which they also act as controls, with exposure to the same three interventions: 1) NIRS-measurement on skin, skull and dura, 2) Phenylephrine 0.1 mg iv., and 3) inspired oxygen fraction of 0.3 vs. 0.8
One strategy for all enrolled patients:	Phenylephrine's effect on brain oxygenation	All patients will participate in three substudies, in which they also act as controls, with exposure to the same three interventions: 1) NIRS-measurement on skin, skull and dura, 2) Phenylephrine 0.1 mg iv., and 3) inspired oxygen fraction of 0.3 vs. 0.8
One strategy for all enrolled patients:	Normal vs. high inspired oxygen	All patients will participate in three substudies, in which they also act as controls, with exposure to the same three interventions: 1) NIRS-measurement on skin, skull and dura, 2) Phenylephrine 0.1 mg iv., and 3) inspired oxygen fraction of 0.3 vs. 0.8

Primary Outcome Measures

Name	Time	Method
ScO2 (NIRS-measured cerebral oxygen saturation)	During surgical procedure	Difference in ScO2 between dura and skin (Primary analysis for substudy 1)

Secondary Outcome Measures

Name	Time	Method
PBrO2 (Partial pressure of brain tissue oxygen)	'Normoxia' is induced with FiO2 = 0.30 for 5 minutes, and then changed to 'Hyperoxia' with FiO2 = 0.80 for the subsequent 5 minutes, while registering the Licox-signal.	Cerebral oxygenation during inspired oxygen fraction 0.80 vs. 0.30 (Primary outcome for substudy 3)
ScO2 (NIRS-measured cerebral oxygen saturation)	Measurements will be performed as the surgeon exposes the skull.	Difference in ScO2 between dura and skull, and between skull and skin (this will be the secondary analyses of substudy 1)
ScO2 (NIRS-measured cerebral oxygenation)	NIRS signal is obtained continuously during the Phenylephrine intervention	NIRS-signal during Phenylephrine intervention (this will be the secondary outcome of substudy 2)

Trial Locations

Locations (1)

Rigshospitalet; 🇩🇰 Copenhagen, Denmark