Near Infrared Spectroscopy for Detection of Cerebral Desaturation After Positioning for Neurosurgical Procedures

Study Overview
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Brief Summary
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The occurrence of postoperative cognitive dysfunction (POCD) might be related to intraoperative cerebral desaturation. Positioning for neurosurgical procedures are associated with head rotation, elevation, flexion or extention that may affect blood brain inflow and outflow. Anatomical variations of Willis circle could affect the cerebral blood flow in extreme head position with the development of cerebral ischemia or functional changes of brain. Investigators suppose that detection of cerebral tissue desaturation and its prompt correction could modify the occurence of POCD after these procedures.

Detailed Description
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Standardized anesthesia and perioperative care will be provided to all patiens with positioning for neurosurgical or spinal procedures, where the head is elevated, extended. flected or rotated. In group A before the start of general anesthesia, the baseline level of cerebral tissue oxygenation (rScO2) will be measured using the near-infrared spectroscopy NIRS (Invivo Medtronic) . Continuous measurement of rScO2 will be used for detection of cerebral tissue desaturation. Each desaturation episode will be managed according to a standardized protocol - correction of extreme head position will be followed by optimalisation of mean arterial pressure (MAP), arterial hemoglobin oxygen saturation, end tidal carbon dioxide concentration and a level of hemoglobine concentration. In group B neither measurement of rScO2 nor interventions are provided. Cognitive dysfunction will be assessed by Adenbrooke test before operation and on the fifth postoperative day.

Official Title
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Near Infrared Spectroscopy for Detection of Cerebral Desaturation After Positioning for Neurosurgical Procedure

Conditions
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Cognitive Dysfunction, Patient Positioning

Intervention / Treatment
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* Other: NIRS based protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Glasgow Coma Scale 15, American Society of Anaesthesiologists (ASA) Physical Status Classification System Grade I-III, patient positioning with elevation, rotation, flexion or extention of head Exclusion Criteria: Inability to past the Addenbrooke test, postoperative ventilation, awake phase during surgery, lung disease with retention of carbon dioxide, neurological disease before surgery (aphasia, paresis, blindness, deafness)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm A<br>Brain tissue oxygenation is measured by NIRS. In time of desaturation the interventions according to NIRS based protocol start. | Other: NIRS based protocol<br>* Each desaturation episode will be managed according to a standardized protocol - correction of extreme head position will be followed by optimisation of mean arterial pressure (MAP), arterial hemoglobin oxygen saturation, end tidal carbon dioxide concentration and a level of hemoglobine concentration.<br>|
| No Intervention: Arm B<br>Brain tissue oxygenation is not measured. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of incidence of postoperative cognitive dysfunction (POCD) | Addenbrooke test | 1 day before operation and the fifth´day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Operative position of patient | In grades from neutral position | first 30 minutes | 
| Age of patients | 18 to 79 | the first 5 minutes | 
| Level of exhaled carbon dioxide | In torr | every 5 minutes | 
| Type and duration of procedure | In minutes | 10 minutes after procedure | 
| Dose of catecholamines | In microgramms per kg per minute | 5 minutes after procedure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cognitive Dysfunction, Near-Infrared Spectroscopy, Neurosurgical Procedures