Elevated Intracranial Pressure (ICP)
Conditions
Brief summary
Monitoring the ICP is the most important aspect of the management of these patients. Recently, transorbital ultrasonography has gained popularity as a noninvasive bedside exam that has been shown to be useful in the diagnosis of raised ICP by evaluating the change in the optic nerve sheath diameter (ONSD). Transorbital ultrasonographic measurement of ONSD appears to be a noninvasive, relatively inexpensive bedside examination for the diagnosis of raised ICP. The investigators aimed to determine the changes in ONSD with acute controlled changes in ICP in healthy volunteers. The controlled changes in ICP will be produced by manipulating the PCO2 with the use of Respiract and jugular venous compression with the use of custom made neck collar.
Detailed description
Elevated intracranial pressure (ICP) is a common and potentially life threatening condition arising from a variety of pathological conditions including traumatic brain injury (TBI), intracranial hemorrhage, subarachnoid hemorrhage and brain tumors. Monitoring the ICP is the most important aspect of the management of these patients. Recently, transorbital ultrasonography has gained popularity as a noninvasive bedside exam that has been shown to be useful in the diagnosis of raised ICP by evaluating the change in the optic nerve sheath diameter (ONSD). Transorbital ultrasonographic measurement of ONSD appears to be a noninvasive, relatively inexpensive bedside examination for the diagnosis of raised ICP. The investigators aimed to determine the changes in ONSD with acute controlled changes in ICP in healthy volunteers. The controlled changes in ICP will be produced by manipulating the PCO2 with the use of Respiract and jugular venous compression with the use of custom made neck collar.
Interventions
OTHERUltrasonographic of the optic nerve sheath diameter
On both eyes of all subjects in supine position by two investigators.
OTHERRespirAct™
Carbon dioxide Manipulation by RespirAct™ sequential gas delivery breathing circuit at each CO2 levels (normocapnia, Hypercapnia I and II and hypocapnia).
OTHERNeck collar
Internal jugular compression using a Neck collar will be applied at each CO2 levels (normocapnia, Hypercapnia I and II and hypocapnia) and ONSD measurements will be done before and after the collar.
Sponsors
University Health Network, Toronto
Lashmi Venkatraghavan
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Adult healthy volunteers who are above the age of 18 ASA 1 Body mass index (BMI) less than and equal to 35 Neurologically normal subjects with no symptoms other than occasional non-severe headache
Exclusion criteria
BMI above 35 Lack of informed consent Language barrier Medical students and/or anesthesia residents going through the department as part of their rotation Pregnancy Frequent migraine headache
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in ONSD in mm With Changes in ICP in Healthy Volunteers. | 1 day | Transorbital ultrasound will be used for measuring the changes in ONSD. The controlled changes in ICP will be produced by manipulating the PCO2 with the use of Respiract and jugular venous compression with the use of custom made neck collar. |
Countries
Canada
Participant flow
Recruitment details
Adult healthy volunteers who are above the age of 18 ASA 1 Body mass index (BMI) less than and equal to 35 Neurologically normal subjects with no symptoms other than occasional non-severe headache
Participants by arm
| Arm | Count |
|---|---|
| Ultrasonographic of the Optic Nerve Sheath Diameter Use transorbital ultrasound to evaluate ONSD changes in patients with intracranial pathology and to compare the changes in the ONSD before and after surgical intervention as well as between patients with and without clinical or radiological signs of increased ICP | 100 |
| Total | 100 |
Baseline characteristics
| Characteristic | Ultrasonographic of the Optic Nerve Sheath Diameter | — |
|---|---|---|
| Age, Customized Participants | 100 Participants | — |
| Intracranial pathology scheduled for elective or emergency surgery | 100 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Region of Enrollment Canada | 100 participants | — |
| Sex: Female, Male Female | 50 Participants | — |
| Sex: Female, Male Male | 50 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 100 |
| other Total, other adverse events | 0 / 100 |
| serious Total, serious adverse events | 0 / 100 |
Outcome results
Primary
Changes in ONSD in mm With Changes in ICP in Healthy Volunteers.
Transorbital ultrasound will be used for measuring the changes in ONSD. The controlled changes in ICP will be produced by manipulating the PCO2 with the use of Respiract and jugular venous compression with the use of custom made neck collar.
Time frame: 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Ultrasonographic of the Optic Nerve Sheath Diameter | Changes in ONSD in mm With Changes in ICP in Healthy Volunteers. | 4.2 mm | Standard Deviation 0.7 |