Assessment of Cerebral Vasoreactivity Using Near-infrared Spectroscopy (NIRS) in Infants (VARO) (VARO)

Assessment of Cerebral Vasoreactivity Using Near-infrared Spectroscopy (NIRS) in Infants

The purpose of this study is to show that a permissive hypercapnia during mechanical ventilation in children under general anaesthesia will improve cerebral perfusion.

Study Overview

• Status: Completed
• Conditions: Hypercapnia
• Intervention / Treatment: Other: Normocapnia; Other: Mild Hypercapnia

Detailed Description

Mechanical ventilation interferes with cerebral perfusion via the changes in intrathoracic pressure and/or as a consequence of hypocapnia. This latter occurs frequently following traditional ventilation strategies with relatively high tidal volume and respiratory rate. New trends in anesthesia intend to promote protective lung ventilation by keeping a normocapnic or even mildly hypercapnic state. However, cerebral vascular vasotonicity is carbon dioxide (CO2)-dependent with hypocapnia potentially leading to vasoconstriction and subsequent decrease in cerebral blood flow. Changes in cerebral vasoreactivity can be assessed by the near infrared spectroscopy (NIRS) device. This monitoring evaluates the changes in various parameters (deoxygenated hemoglobin, oxygenated hemoglobin, the tissue oxygenation index (TOI) and the tissue hemoglobin index (THI)) that act as surrogate for cerebral vasoconstriction.

We, therefore designed this prospective observational comparative effectiveness study in order to characterize the potential beneficial effect of permissive hypercapnia on cerebral perfusion in infants.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Geneva, Switzerland, 1206
    • Geneva Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 1 year to 4 months (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• term neonates during their infancy
• for elective surgery requiring general anesthesia and endotracheal intubation

Exclusion Criteria:

• all infants with cardiac anomalies, chronic pulmonary disease (bronchopulmonary dysplasia, cystic fibrosis, asthma), pulmonary hypertension or cranial hypertension will be excluded
• all infants where no access to the forehead is possible as a consequence of the operating field

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Normocapnia; The Child will be ventilated in order to achieve an end-tidal carbon dioxide (ETCO2) of 5.5 kiloPascal (kPa). Measurements will be performed after steady state condition. Then the ventilation will be reduced to allow ETCO2 to reach 6.5 kPa before repeating the measurements. Finally, the child will be again ventilated to obtain a normocapnia condition.	Other: Normocapnia; Normoventilation in order to have an end-tidal carbon dioxide (ETCO2) of 5.5 kiloPascal (kPa)
Other: Mild Hypercapnia; The Child will be ventilated in order to achieve a ETCO2 of 6.5 kPa. Measurements will be performed after steady state condition. Then the ventilation will be increased to allow ETCO2 to reach 5.5 kPa before repeating the measurements. Finally, the child will be again ventilated to obtain a mild hypercapnic condition	Other: Mild Hypercapnia; Decrease in minute ventilation in order to increase ETCO2 to 6.5 kPa

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Assessment of the changes in TOI and THI as measured by NIRS under normocapnia and permissive hypercapnia	At steady state (2-3 minutes) after achieving each level of ETCO2 and every 2 minutes up to 6 minutes for each level

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood gas analysis	Assessment changes in oxygen partial pressure (PaO2), carbon dioxide partial pressure (PaCO2) and potential of hydrogen (pH) under one level of ETCO2	5 or 20 minutes after reaching the steady state with ETCO2
Blood Pressure	Non invasive monitoring of blood pressure	At steady state (2-3 minutes) after achieving each level of ETCO2 and every 2 minutes up to 6 minutes for each level
Heart rate	Non invasive recording of heart rate	At steady state (2-3 minutes) after achieving each level of ETCO2 and every 2 minutes up to 6 minutes for each level
Body temperature	Naso-pharyngeal temperature probe	At steady state (2-3 minutes) after achieving each level of ETCO2 and every 2 minutes up to 6 minutes for each level

Collaborators and Investigators

• Sponsor: Walid HABRE

Publications and helpful links

General Publications

• Schopfer L, Habre W, Pichon I, Fodor GH. Effect of Permissive Mild Hypercapnia on Cerebral Vasoreactivity in Infants: A Randomized Controlled Crossover Trial. Anesth Analg. 2021 Oct 1;133(4):976-983. doi: 10.1213/ANE.0000000000005325.

Study record dates

Study Major Dates

• Study Start: September 1, 2015
• Primary Completion (Actual): September 1, 2017
• Study Completion (Actual): September 30, 2017

Study Registration Dates

• First Submitted: March 11, 2015
• First Submitted That Met QC Criteria: April 23, 2015
• First Posted (Estimate): April 29, 2015

Study Record Updates

• Last Update Posted (Actual): January 4, 2018
• Last Update Submitted That Met QC Criteria: January 3, 2018
• Last Verified: January 1, 2018

More Information

Terms related to this study

• Keywords: Infant; Anesthesia, general; spectroscopy, near-infrared
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypercapnia
• Other Study ID Numbers: 14-204