Effect of PEEP on Subdural Pressure, Optic Nerve Sheath Diameter, Lung Compliance and Brain Perfusion Pressure

Not Applicable

• Conditions: Anesthesia, General; Optic Nerve; Supratentorial Neoplasms
• Interventions: Procedure: PEEP variations

• Registration Number: NCT04316208
• Lead Sponsor: Istanbul University

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.

Study Timeline

• Status Verified: 2020-03
• Study Start: 2020-03-01
• Study First Submitted: 2020-03-18
• Study First Submitted QC: 2020-03-19
• Last Update Submitted: 2020-03-19
• Study First Posted: 2020-03-20
• Last Update Posted: 2020-03-20
• Primary Completion: 2021-04-01
• Study Completion: 2021-09-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 50

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Supratentorial tumor surgery	PEEP variations	Patients undergoing elective supratentorial tumor surgery under general anesthesia will be ventilated with positive end-expiratory pressures of 0, 5 and 10 cmH2O after craniotomy.

Primary Outcome Measures

Name	Time	Method
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
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.

Secondary Outcome Measures

Name	Time	Method
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
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
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
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
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

Trial Locations

Locations (1)

Istanbul University - Cerrahpasa, Department of Neurosurgery, Neurosurgical Theaters; 🇹🇷 Istanbul, Turkey