Ventilation With High Oxygen Content and Postoperative Pneumocephalus

Study Overview
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Brief Summary
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The aim of this study is to compare the incidence and volume of postoperative pneumocephalus in patients receiving ventilation with 100% oxygen during the last stage of surgery versus a conventional 1:1 oxygen/air gas mixture.

Detailed Description
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Background: Postoperative pneumocephalus is a common complication in patients undergoing craniotomies. Even though the treatment of postoperative pneumocephalus with the use of supplemental oxygen is well documented, yet not reports have shown its role for the prevention of this condition. We suggest the use of intraoperative ventilation with 100% oxygen as prophylaxis for the incidence and severity of postoperative pneumocephalus in patients undergoing intracranial surgery. Objectives: The aim of this study is to compare the incidence and volume of postoperative pneumocephalus in patients receiving ventilation with 100% oxygen during the last stage of surgery versus a conventional 1:1 oxygen/air gas mixture. Study Methods: A single-blinded, prospective study, randomizing 80 patients per group, expecting 80% power to detect a 20% decrease in pneumocephalus volume for the interventional group. Inclusion criteria: Patients >18 years, scheduled to undergo elective craniotomy, and be willing to give written informed consent. Study Procedures: Once the tumor resection is completed and hemostasis started (beginning of stage 2), patients will be assigned to receive either 1:1 oxygen/air gas mixture (control group) or 100% oxygen (intervention group) until the end of the surgery. All patients will receive postoperative supplemental oxygen via nasal cannula. CT scan will be performed within 1 to 6 postoperative hours as standard of care. A blinded radiologist will review all CT scans and assess the extent and frequency of postoperative pneumocephalus. Clinical Outcomes: Patients' demographic data, length of stage 2, period of time between the end of surgery and CT scan, and pneumocephalus volumetric measurements will be compared between groups. Baseline neurological status will be compared with clinical and imaging postoperative findings.

Official Title
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Impact of Intraoperative Ventilation With High Oxygen Content to Reduce the Incidence and Extent of Postoperative Pneumocephalus in Patients Undergoing Craniotomies

Conditions
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Pneumocephalus

Intervention / Treatment
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* Other: Controlled Ventilation with 100% oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients > 18 years of both sexes undergoing surgical procedures to treat hemispheric or posterior cranial fossa tumors and consenting to the study Exclusion Criteria: History of severe cardio-pulmonary disease. Bleeding disorders Previous neurosurgeries requiring cranial reconstruction Head trauma Decreased consciousness related to cerebral edema

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Conventional 1:1 oxygen/air gas mixture<br>80 patients will receive ventilation during the surgery with a 1:1 oxygen / air gas mixture | |
| Experimental: Pure oxygen ventilation<br>Patients will receive controlled ventilation with a conventional 1:1 oxygen / air gas mixture (60% oxygen concentration) during the approach and tumor removal phases. Once tumor resection is completed and hemostasis started, this group of patients will be switched to ventilation with 100% (pure) oxygen concentration | Other: Controlled Ventilation with 100% oxygen<br>* Patients in group B will be switched from conventional 1:1 oxygen / air ventilation to 100% oxygen controlled ventilation once tumor resection is completed and hemostasis started. They will inhale 100% oxygen until extubation<br>* Other names: FiO2 100% after tumor resection;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Volume of Postoperative Pneumocephalus | Compare the extent (cm3) of postoperative pneumocephalus in patients ventilated intraoperatively with 100% oxygen during hemostasis and wound closure versus 1:1 oxygen / air mixture | One to six hours after surgery | 
| Occurrence of Postoperative Pneumocephalus | Compare the occurrence rate of postoperative pneumocephalus (present or not present) in patients receiving intraoperative ventilation with 100% oxygen during hemostasis and wound closure versus 1:1 oxygen / air mixture | One to six hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pneumocephalus Volume and Anterior Fossa Surgery | To compare the presence of postoperative pneumocephalus in patients who underwent anterior fossa surgery. | One to six hours after surgery | 
| Pneumocephalus Volume and Posterior Fossa Surgery | Pneumocephalus volume in patients who underwent posterior fossa surgery | one to six hours after surgery | 
| Changes in Neurological Outcomes at POD 3 Compared to Preoperative Evaluation | Changes in Neurological Outcomes from baseline (preoperative evaluation) were documented based on differences (if any) found between both physical examinations: baseline (before surgery) and postoperative day (POD) 3 neurological exam. Results were reported as improvement (partial or total recovery of baseline neurological signs/symptoms), no changes, and deterioration (focal or global neurological deterioration) in comparison with baseline neurological examination | preoperative to postoperative day 3 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Postoperative pneumocephalus, Fraction of inspired oxygen, Intracranial surgery