Low Fresh Gas Flow in Prone Position

Study Overview
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Brief Summary
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Low flow anesthesia in the prone position was safe in terms of systemic hemodynamics and did not reduce cerebral oxygenation compared to normal flow.

Detailed Description
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Patients were randomly allocated to either low fresh gas flow(LF, 0,5 L/min during maintenance) or normal flow (NF, 2 L/min)) general anesthesia. In both groups, participants were first administered with 100% oxygen at a 4 L/min flow rate. Propofol 2-2,5 mg/kg, rocuronium bromide 0,6 mg/kg, and fentanyl 1 mcg/kg IV were used for anesthesia induction.In the operating room, pulse rate, mean arterial pressure (MAP), peripheral hemoglobin oxygen saturation (spO2), and right and left side regional cerebral oxygen saturation (Masimo's O3 regional oximetry device) were measured before premedication and anesthesia induction, at 10 minutes after endotracheal intubation, at 10 minutes after prone positioning, at 1st, 2nd, 3rd, 4th and 5th hours of operation, before repositioning to supine, after the resumption of supine position and at 5 minutes after extubation. In conclusion, low flow anesthesia in patients undergoing surgery in the prone position did not cause a reduction in cerebral oxygenation compared to normal flow.

Official Title
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Low Fresh Gas Flow and Normal Gas Flow Anesthesia in Patients Undergoing Surgery in Prone Position: Impact on Hemodynamics and Regional Cerebral Oxygenation

Conditions
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Anesthesia

Intervention / Treatment
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* Procedure: Low Fresh Gas Flow in Prone Position
* Procedure: Normal Fresh Gas Flow in Prone Position


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: undergoing surgery in the prone position having an American Society of Anesthesiologists (ASA) physical status I to III willingness to participate in the study Exclusion Criteria: having a Glasgow coma scale (GSC) score ≤ 12 previous history of cranial surgery advanced cardiovascular and/or pulmonary disease mental retardation neurological disease

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low Fresh Gas Flow in Prone Position<br>Low fresh gas flow (0,5 L/min during maintenance) | Procedure: Low Fresh Gas Flow in Prone Position<br>* In the low fresh gas flow group, the flow rate was reduced to 0.5 L/min<br>|
| Active Comparator: Normal Fresh Gas Flow in Prone Position<br>Normal flow (2 L/min) in general anesthesia. | Procedure: Normal Fresh Gas Flow in Prone Position<br>* In the normal flow rate group, the gas flow rate was reduced to 2 L/min during the maintenance phase.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Low and Normal Fresh Gas Flow Difference in Prone Position | Whether low flow anesthesia in the prone position is safe in terms of systemic hemodynamics and cerebral oxygenation compared to normal flow anesthesia | Systemic and cerebral oxygenation values were measured 10 minutes after induction to general anesthesia and followed up to 10 minutes were left to completion of the surgery for about 5 hours, which may vary according to the duration of the surgery. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hemodynamics, Low Flow Anesthesia, Near Infrared Spectroscopy, Prone Positioning, Regional Cerebral Oxygenation