AGC Mode vs Minimal Flow in Breast Surgery

Zonguldak Bulent Ecevit University

Status: Completed

Conditions: Anesthesia; Functional; Breast Diseases; Automatic End-tidal Controlled Anesthesia; Volatil Agent Consumption

Treatments: Device: AGC mode

Study type: Observational

Funder types: Other

Identifiers

NCT05404269

2021/05-12

Details and patient eligibility

About

The aim of this study was to compare the AGC mode and manually controlled minimal-flow anesthesia for volatile anesthetic consumption, hemodynamic parameters, and recovery from anesthesia

Full description

Modern anesthesia machines use circular systems in which ventilated gas re-circulates to a certain degree and is therefore reused, preserving temperature, and humidity. The rebreathing fraction is increased by a reduction in fresh gas flow, which leads to a considerable decrease in consumption of fresh gas and volatile anesthetics, resulting in reductions in cost and atmospheric pollution. In a closed ventilation system, only the patient's requirements for oxygen and anesthetic agents are supplemented. A fresh gas flow-rate of 0.5 l/min is defined as the minimal-flow technique. The oxygen and anesthetic gas titration can be manually controlled by the anesthetist. To assure safe and appropriate anesthesia, manually controlled anesthesia requires constant monitoring and numerous adjustments to the gas dosage by the anesthetist, especially for low- and minimalflow anesthesia. Oxygen flow and volatile anesthetics can also be automatically controlled by anesthesia machines using end-tidal control (such as AGC mode of Maquet FLOW-i anesthesia machine), which ensures constant end-tidal concentration of oxygen and anesthetic gas via feedback and continuous automatic adjustment mechanisms. Anesthesiologists needing to make fewer interventions during a case may have clinical importance in terms of distraction, record keeping and patient safety. In addition to this advantage, we wanted to compare the AGC mode and manually controlled minimal-flow anesthesia for volatile anesthetic consumption, hemodynamic parameters, and recovery from anesthesia.

Enrollment: 90 patients

Sex: Female

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 18-65 years
• undergoing breast surgery
• ASA physical status I-II
• female
• operation lasting at least 1 hour
• those who agreed to volunteer for the study with an informed consent form

Exclusion criteria

• coronary artery disease, CHF
• pregnancy or breastfeeding women
• decompensated diabetes mellitus
• kidney or liver failure
• chronic obstructive pulmonary disease
• opioid sensitivity
• history of malignant hyperthermia
• history of smoking
• alcohol or drug addiction
• significant anemia
• sepsis
• BMI >35
• patients with allergies to the drugs used in the study

Trial design

90 participants in 3 patient groups

Group AGC

Description:

The FLOW-i anesthesia machine (Maquet, Solna, Sweden) can be equipped with automated gas control (AGC), an automated low flow tool with target control of the inspired oxygen concentration (FIO2) and end-expired concentration (FA) of a potent inhaled anesthetic. İnitially before induction, we set the minimal fresh gas flow to 0.5 L min-1 and target end-expired agent concentration for 1 MAC (minimal alveolar concentration). Shortly after intubation of the patient, we switched to AGC mode.

Treatment:

Device: AGC mode

Group Minimal Flow

Description:

İn this group; following intubation, we set the fresh gas flow to 4 L min-1 and than we readjusted fresh gas flow manually to 0.5 L min-1 after sevoflurane concentration reaching to 1 MAC.

Group Medium Flow

Description:

İn this group; following intubation, we set the fresh gas flow to 4 L min-1 and than we readjusted fresh gas flow manually to 2 L min-1 after sevoflurane concentration reaching to 1 MAC.