Anesthesia, General, Optic Nerve, Supratentorial Neoplasms
Conditions
Brief summary
We aim to determine the level of intraoperative PEEP that optimizes lung compliance without causing a rise in subdural pressure and if we can utilize optic nerve sheath diameter measurement as an indicator for ICP while optimizing lung compliance during supratentorial tumor surgeries.
Detailed description
Application of positive end-expiratory pressure (PEEP) during general anesthesia minimizes ventilation/perfusion mismatch, intraoperative atelectasis and postoperative pulmonary complications. PEEP application in intracranial surgeries is usually avoided due to the risk of raised intracranial pressure (ICP) leading to decreased cerebral perfusion pressure (CPP). Several studies examine the effects of PEEP on subdural pressure and CPP however none examine how lung compliance is affected at the same time. Ultrasound-guided measurement of optic nerve sheath diameter (ONSD) is an indirect indicator of raised ICP and there is limited literature on the correlation of ONSD and ICP during intracranial surgery. In this study, we aim to determine the level of intraoperative PEEP that optimizes lung compliance without causing a rise in subdural pressure and if we can utilize ONSD measurement as an indicator for ICP while optimizing lung compliance during supratentorial tumor surgeries.
Interventions
PROCEDUREPEEP variations
Patients will be ventilated with a PEEP of 5 cmH2O during induction of anesthesia. After craniotomy, the PEEP will be reduced to 0 cmH2O for 5 minutes and data will be collected at the end of 5 minutes. Next, PEEP will be increased to 5 cmH2O for 5 minutes and data will be collected at the end of 5 minutes. Finally, PEEP will be increased to 10 cmH2O for 5 minutes and data will be collected at the end of 5 minutes.
Sponsors
Istanbul University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Masking description
Care provider will adjust the PEEP level, make measurements and record arterial blood gas analysis results. Biostatistician will compare data set at each PEEP to each other. Investigator will analyze the data
Intervention model description
After craniotomy, PEEP will be adjusted to 0 cmH2O, 5 cmH2O and 10 cmH2O for 5 minutes each to collect the data
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Supratentorial tumor * Elective surgery * American Society of Anesthesiologist Class I, II or III
Exclusion criteria
* Midline shift more than 5 mm determined by intracranial imaging * Initial subdural pressure higher than 20 mmHg * Requiring intravenous mannitol or hypertonic saline treatment before dural opening * Congestive heart failure * Pulmonary hypertension * Sepsis * Hypovolemia * Obstructive or restrictive lung disease
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Optic nerve sheath diameter (left and right) | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | Ultrasound-guided measurement with the linear probe. |
| Subdural pressure | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | 22G/ 0.9mm catheter will be introduced into subdural space after craniotomy and connected to the transducer for pressure measurement |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Brain relaxation index | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | 1: dura is under the cranium, 2: dura is at the level of the cranium, 3: dura is above the cranium 4: dural pulsations ceased |
| Regional cerebral oxygen saturation | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | % - measurement taken with INVOS cerebral oximeter |
| Lung compliance | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | L/cmH2O - measurement taken from Draeger Dräger Perseus® A500 mechanical ventilator |
| Arterial blood gases | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | Arterial oxygen pressure and arterial carbon dioxide pressure will be recorded |
| Mean arterial pressure | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | Invasive blood pressure monitoring will be done. The transducer will be kept at the same level as the transducer for the subdural pressure, at the level of the external ear canal |
Other
| Measure | Time frame | Description |
|---|---|---|
| P/F ratio | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | Obtained by PaO2/FiO2. Hence FiO2 will be recorded at the times of measurements |
| Brain perfusion pressure | Measurements will look at the change between 3 timepoints: at 5 minutes with PEEP of 0 cmH2O (T0), then at 5 minutes with PEEP of 5 cmH2O (T5), and finally at 5 minutes with PEEP of 10 cmH2O (T10) | Calculated from subdural pressure and mean arterial pressure |
Countries
Turkey (Türkiye)
Contacts
Primary ContactÖzlem Korkmaz Dilmen, MD
Backup ContactEren F Akcil, MD
Outcome results
None listed