MAAS Method (Minimal-flow Auto-control Anesthesia System) for the Administration of Desflurane and Sevoflurane

NCT05511610 | Completed

• 1 other identifier: MAAS.Sevo.Desfl.accuracy
• Study Type: interventional
• Target: 28
• Locations: 1 country
• Sites: 1

Brief Summary

In the present work the investigators will study the accuracy of the MAAS (Minimal-flow Autocontrol Anesthesia System) method to estimate the percentage of halogenated anesthetic (HA) to be supplied to the anesthetic circuit based on the estimation of HA uptake during the maintenance phase. The investigators will evaluate the accuracy of sevoflurane and desflurane vaporizers to guarantee the administration of that amount of estimated HA, thus guaranteeing the maintenance of the target concentration of HA at the end of expiration: end-tidal target HA% (ettHA%). To do this, the investigators will quantify the number of adjustments that need to be made to each vaporizer to maintain ettHA%. As secondary objectives, the investigators will analyze the time to reach the target concentration of HA, the deviations that occur from that concentration despite the correct application of the method, and the consumption of HA during the procedure. Through the entire procedure, all participants will be ventilated under a tailored open lung approach (tOLA) strategy.

Conditions

Anesthesia; Sevoflurane; Desflurane; Low Flow Anesthesia

Keywords

Sevoflurane; Desflurane; Anesthesia, Closed-Circuit

Outcome Measures

Primary Outcomes (2)

• Changes made in the sevoflurane vaporizer

  Number of adjustments that must be made in the sevoflurane vaporizer to maintain the predefined end-tidal target of sevoflurane (ettSEVO%).

  60 minutes, starting from the end of Phase sevo 1 (once filled the HPO compartment)

• Changes made in the desflurane vaporizer

  Number of adjustments that must be made in the desflurane vaporizer to maintain the predefined end-tidal target of desflurane (ettDESFLU%).

  60 minutes, starting from the end of Phase desflu 1(once filled the HPO compartment)

Secondary Outcomes (5)

• Time to reach the ettSEVO%

  Immediately after OTI and until completing the Phase sevo 1

• Time to reach the ettDESFLU%

  Immediately after completing the Washout phase and until completing the Phase desflu 1.

• Deviations from ettSEVO% despite the correct application of the method

  60 minutes: starting from the end of Phase sevo 1 until the end of Phase sevo 2

• Deviations from ettDESFLU% despite the correct application of the method

  60 minutes: starting from the end of Phase desflu1 until the end of Phase desflu 2

• Consumption of HA (ml of HA in its liquid phase) during the procedure

  During the procedure: starting pre-intervention and immediately after the procedure

Study Arms (1)

MAAS method trial

EXPERIMENTAL

Accuracy of sevoflurane and desflurane vaporizers to guarantee the ettHA%, based on the MAAS method.

Procedure: Sevoflurane uptake and supply; Procedure: Washout phase; Procedure: Desflurane uptake and supply; Procedure: Final phase

Interventions

Sevoflurane uptake and supply PROCEDURE

Phase sevo 1) * Moment 1 (M1): from OTI until end-tidal sevoflurane (etSEVO%) exceeds ettSEVO% by 10%. Deliver of sevoflurane to the system (SEVOdel) carried out by completely opening sevoflurane vaporizer (8%). * M2) once etSEVO% surpass ettSEVO% by 10%: turn off sevoflurane vaporizer and observe the progressive fall etSEVO%. When etSEVO% approaches ettSEVO% (0.1-0.2 points above ettSEVO%), the investigators will turn on the sevoflurane vaporizer following the MAAS method to ensure stability in inspired and expired concentrations of sevoflurane. Phase sevo 2) Objective: to maintain etSEVO% = ettSEVO% ±5% When the etSEVO% increases above the mentioned levels \>\> reduce SEVOdel by 0.25-0.5%. When the etSEVO% decreases below the mentioned levels\>\> increase SEVOdel by 0.25-0.5%.

MAAS method trial

Washout phase PROCEDURE

The investigators will close the sevoflurane vaporizer and will start the administration of Propofol in intravenous perfusion; the investigators will then open the FGF sequentially at 2\>5\>10 liters per minute (LPM), until the etSEVO% is \<0.2 MAC.

MAAS method trial

Desflurane uptake and supply PROCEDURE

Phase desflu 1) * Moment 1 (M1): from the end of Washout phase until end-tidal desflurane (etDESFLU%) exceeds ettDESFLU% by 10%. Deliver of desflurane to the system (DESFLUdel) carried out by completely opening the desflurane vaporizer (18%). * M2) once etDESFLU% surpass ettDESFLU% by 20%: turn off the desflurane vaporizer and observe the progressive fall etDESFLU%. When etDESFLU% approaches ettDESFLU% (0.8-1.2 points above ettDESFLU%), the investigators will turn on the desflurane vaporizer following the MAAS method to ensure stability in inspired and expired concentrations of desflurane. Phase desflu 2) Objective: to maintain etDESFLU% = ettDESFLU% ±5% When the etDESFLU% increases above the mentioned levels \>\> reduce DESFLUdel by 0.25-0.5%. When the etDESFLU% decreases below the mentioned levels\>\> increase DESFLUdel by 0.25-0.5%.

MAAS method trial

Final phase PROCEDURE

From the end of Phase desflu 2 until the end of the intervention. Maintenance of anesthesia with desflurane following the principles of MAAS Method. Between 15-20 minutes before the end of the intervention, the investigators will stop the administration of desflurane, registering the time until the reaching etDESFLU% \< 0.2 MAC.

MAAS method trial

Eligibility Criteria

• Age: 18 Years - 99 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult subjects (≥ 18 years) scheduled for robotic urological, coloproctological or gynecological surgery in the investigators´ institution
• Written informed consent

You may not qualify if:

• Participation in another interventional study
• Participants unable to understand the information contained in the informed consent
• American Society of Anesthesiologists (ASA) classification grade = IV
• Patient in dialysis
• Chronic obstructive pulmonary disease (COPD) grade Global Initiative for Chronic Obstructive Lung Disease(GOLD) \> 2
• Functional vital capacity \< 60% or \> 120% of the predicted
• Body mass index (BMI) \> 35 kg/m2
• New York Heart Association (NYHA) functional class ≥ 3
• Clinically suspected heart failure
• Diagnosis or suspicion of intracranial hypertension
• Presence of pneumothorax or giant bullae on preoperative imaging tests
• Use of Continuous Positive Airway Pressure (CPAP).

Sponsors & Collaborators

• Fundación Pública Andaluza para la gestión de la Investigación en Sevilla: lead

Study Sites (1)

Hospital Universitario Virgen del Rocío

Seville, 41013, Spain

Location

Related Publications (9)

• McGain F, Muret J, Lawson C, Sherman JD. Environmental sustainability in anaesthesia and critical care. Br J Anaesth. 2020 Nov;125(5):680-692. doi: 10.1016/j.bja.2020.06.055. Epub 2020 Aug 12.

  PMID: 32798068 BACKGROUND

• Sherman J, Le C, Lamers V, Eckelman M. Life cycle greenhouse gas emissions of anesthetic drugs. Anesth Analg. 2012 May;114(5):1086-90. doi: 10.1213/ANE.0b013e31824f6940. Epub 2012 Apr 4.

  PMID: 22492186 BACKGROUND

• Petre MA, Malherbe S. Environmentally sustainable perioperative medicine: simple strategies for anesthetic practice. Can J Anaesth. 2020 Aug;67(8):1044-1063. doi: 10.1007/s12630-020-01726-0. Epub 2020 Jun 8.

  PMID: 32514694 BACKGROUND

• Brattwall M, Warren-Stomberg M, Hesselvik F, Jakobsson J. Brief review: theory and practice of minimal fresh gas flow anesthesia. Can J Anaesth. 2012 Aug;59(8):785-97. doi: 10.1007/s12630-012-9736-2. Epub 2012 Jun 1.

  PMID: 22653840 BACKGROUND

• Carter LA, Oyewole M, Bates E, Sherratt K. Promoting low-flow anaesthesia and volatile anaesthetic agent choice. BMJ Open Qual. 2019 Sep 13;8(3):e000479. doi: 10.1136/bmjoq-2018-000479. eCollection 2019.

  PMID: 31637316 BACKGROUND

• Colak YZ, Toprak HI. Feasibility, safety, and economic consequences of using low flow anesthesia according to body weight. J Anesth. 2020 Aug;34(4):537-542. doi: 10.1007/s00540-020-02782-y. Epub 2020 May 3.

  PMID: 32363423 BACKGROUND

• Ferrando C, Suarez-Sipmann F, Tusman G, Leon I, Romero E, Gracia E, Mugarra A, Arocas B, Pozo N, Soro M, Belda FJ. Open lung approach versus standard protective strategies: Effects on driving pressure and ventilatory efficiency during anesthesia - A pilot, randomized controlled trial. PLoS One. 2017 May 11;12(5):e0177399. doi: 10.1371/journal.pone.0177399. eCollection 2017.

  PMID: 28493943 BACKGROUND

• Tusman G, Groisman I, Fiolo FE, Scandurra A, Arca JM, Krumrick G, Bohm SH, Sipmann FS. Noninvasive monitoring of lung recruitment maneuvers in morbidly obese patients: the role of pulse oximetry and volumetric capnography. Anesth Analg. 2014 Jan;118(1):137-44. doi: 10.1213/01.ane.0000438350.29240.08.

  PMID: 24356163 BACKGROUND

• Wetz AJ, Mueller MM, Walliser K, Foest C, Wand S, Brandes IF, Waeschle RM, Bauer M. End-tidal control vs. manually controlled minimal-flow anesthesia: a prospective comparative trial. Acta Anaesthesiol Scand. 2017 Nov;61(10):1262-1269. doi: 10.1111/aas.12961. Epub 2017 Aug 22.

  PMID: 28832896 BACKGROUND

MeSH Terms

Interventions

Equipment and Supplies

Study Officials

• Manuel de la Matta, PhD

  Hospitales Universitarios Virgen del Rocío

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 18, 2022
• First Posted: August 23, 2022
• Study Start: April 3, 2024
• Primary Completion: June 30, 2025
• Study Completion: June 30, 2025
• Last Updated: July 23, 2025

Record last verified: 2025-07

Locations

ES (1)