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.

Study Overview

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

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Copenhagen, Denmark, 2100
    • Rigshospitalet

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: One strategy for all enrolled patients: 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

Device: NIRS measurements on skin, skull and dura; During a neurosurgical procedure, we will measure the brain oxygenation with a NIRS-electrode, first on forehead skin, then on the skull and finally directly on dura.; Drug: Phenylephrine's effect on brain oxygenation; With a Clark-electrode (Licox(R)) in the white matter and a NIRS-electrode on the forehead skin, we will give a small dose (0.1 mg iv.) Phenylephrine.; Drug: Normal vs. high inspired oxygen; By the end of the neurosurgical procedure, still with a Clark-electrode in the white matter and a NIRS-electrode on forehead skin, we will change the inspired oxygen fraction from 0.3 to 0.8.

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PBrO2 (Partial pressure of brain tissue oxygen)	Cerebral oxygenation, measured by a Clark-electrode (Licox (R)) (Primary outcome measure for substudy 2)	During surgical procedure
PBrO2 (Partial pressure of brain tissue oxygen)	Cerebral oxygenation during inspired oxygen fraction 0.80 vs. 0.30 (Primary outcome for substudy 3)	'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.
ScO2 (NIRS-measured cerebral oxygen saturation)	Difference in ScO2 between dura and skull, and between skull and skin (this will be the secondary analyses of substudy 1)	Measurements will be performed as the surgeon exposes the skull.
ScO2 (NIRS-measured cerebral oxygenation)	NIRS-signal during Phenylephrine intervention (this will be the secondary outcome of substudy 2)	NIRS signal is obtained continuously during the Phenylephrine intervention

Collaborators and Investigators

• Sponsor: University Hospital Bispebjerg and Frederiksberg

Study record dates

Study Major Dates

• Study Start (Actual): September 24, 2018
• Primary Completion (Actual): October 1, 2020
• Study Completion (Actual): October 1, 2020

Study Registration Dates

• First Submitted: August 28, 2018
• First Submitted That Met QC Criteria: September 21, 2018
• First Posted (Actual): September 24, 2018

Study Record Updates

• Last Update Posted (Actual): November 3, 2020
• Last Update Submitted That Met QC Criteria: November 2, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Protective Agents; Adrenergic alpha-Agonists; Adrenergic Agonists; Cardiotonic Agents; Respiratory System Agents; Sympathomimetics; Vasoconstrictor Agents; Mydriatics; Nasal Decongestants; Adrenergic alpha-1 Receptor Agonists; Phenylephrine; Oxymetazoline
• Other Study ID Numbers: Neuro-Ox 2018

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No