Correlating Brain Tissue Oxygen and Regional Cerebral Oximetry

NCT03128957 | Completed Results FDA Device

• 1 other identifier: HUM00105648
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

Controversy surrounds the use of regional cerebral oximetry (rSO2) as a measure of true cerebral oxygenation because of extracranial signal contamination and unmeasured confounding of cerebral a:v ratio. The measurement of brain tissue oxygen (PbrO2) has been used in routine neurosurgery and has been shown to reliably demonstrate cerebral hypoxia following severe head injury. It is the most direct measure of cerebral oxygenation. Here, we test the hypothesis that there is a correlation between PbrO2 and rSO2 under conditions of varying inspired oxygen fraction and the varying partial pressure of carbon dioxide in arterial blood in uninjured, normal human brain. Patients who are scheduled for elective removal of secondary cerebral metastases under general anesthesia will be recruited following written informed consent obtained by a study team member during their preoperative evaluation. BIS and rSO2 optodes will be applied, before induction of anesthesia, by a single researcher on both sides of the patient's forehead, as recommended by the manufacturer. General anesthesia will be maintained by total intravenous anesthesia (TIVA) with a combination of propofol (80-150 mcg/kg/min) and remifentanil (0.05-0.1 mcg/kg/min) targeted to a Bispectral Index range 40-60 (BIS; Covidien, Boulder, CO). Following craniotomy, the LICOX probe will be placed under direct vision into an area of normal brain within the tumor excision canal by the attending neurosurgeon. During a pause in surgery FIO2 and minute ventilation will be sequentially adjusted to achieve the following pairs of ventilation set points: 1) FIO2 0.3 and paCO2 30mmHg, 2) FIO2 1.0 and paCO2 40mmHg. After ≥5 minutes at each set point FIO2, PaCO2, rSO2 and PbrO2 will be recorded as a "snap-shot". A sample size of 15 achieves an 80% power with a one-sided type I error of 5% to detect a positive correlation of 0.6 (from the null hypothesis of no correlation) between changes in PbrO2 and changes in rSO2 subsequent on alterations made in ventilation strategy. Correlation will be measured using Pearson's Correlation. P values \< 0.05 will be considered statistically significant.

Conditions

Stroke

Outcome Measures

Primary Outcomes (1)

• Correlation Between Regional Cerebral Oximetry (RSO2) and Cerebral Oxygen Tissue Tension (PbrO2).

  Correlation - correlation coefficient between cerebral oxygenation measured by Licox and INVOS oxygen measurement systems subsequent upon changes in ventilation strategy Spearman correlation describes the strength of the monotonic relationship between two measures and is bounded between -1 and 1. Negative values indicate an inverse relationship while positive values mean that the variables move in tandem. \[Example of correlation coefficient in CT.gov: NCT02318667\]

  Time required for cerebral oxygenation to reach equilibrium following a change in ventilation - typically less than 20 minutes

Secondary Outcomes (2)

• Changes in PbrO2 Resultant Upon Changes in End Tidal Carbon Dioxide and Inspired Oxygen Fraction

  Time required for cerebral oxygenation to reach equilibrium following a change in ventilation - typically less than 20 minutes

• Changes in rSO2 Resultant Upon Changes in End Tidal Carbon Dioxide and Inspired Oxygen Fraction

  Time required for cerebral oxygenation to reach equilibrium following a change in ventilation - typically less than 20 minutes

Study Arms (1)

Varying cerebral oxygenation with varying ventilation

EXPERIMENTAL

Compare oxygenation under conditions of varying ventilation strategy. Low end tidal CO2/Low inspired oxygen vs High end tidal CO2/high inspired oxygen

Device: IVOS cerebral oximeter; Device: Licox cerebral oxygenation monitor; Other: Cerebral oxygenation

Interventions

IVOS cerebral oximeter DEVICE

Measuring percutaneous cerebral oxygenation secondary to changing end tidal carbon dioxide and inspired oxygen fraction.

Varying cerebral oxygenation with varying ventilation

Licox cerebral oxygenation monitor DEVICE

Measuring tissue cerebral oxygenation secondary to changing end tidal carbon dioxide and inspired oxygen fraction.

Varying cerebral oxygenation with varying ventilation

Cerebral oxygenation OTHER

Measuring cerebral oxygenation with varying ventilation strategy

Varying cerebral oxygenation with varying ventilation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients who are scheduled for elective removal of secondary cerebral metastases under general anesthesia.

You may not qualify if:

• Patients will be excluded if they refuse to give consent, have evidence of elevated intracranial pressure on preoperative CT scan, have coagulopathy, are taking therapeutic agents known to increase bleeding risk, have a history of cardiovascular disease, cerebrovascular disease, suffer from respiratory failure, or are not fluent English speakers.

Sponsors & Collaborators

• University of Michigan: lead

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

MeSH Terms

Conditions

Stroke

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases

Results Point of Contact

• Title: Dr. Paul Picton
• Organization: University of Michigan

ppicton@med.umich.edu

734 615 9864

Study Officials

• Paul Picton, MB ChB

  University of Michigan

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: April 14, 2017
• First Posted: April 25, 2017
• Study Start: June 29, 2017
• Primary Completion: June 22, 2021
• Study Completion: June 22, 2021
• Last Updated: September 1, 2022
• Results First Posted: September 1, 2022

Record last verified: 2022-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)