Background: Low-flow anesthesia is increasingly used in modern anesthetic practice because it reduces consumption of volatile anesthetic agents, minimizes environmental pollution, and lowers anesthetic cost. However, accurate monitoring of anesthetic depth is essential to avoid excessive anesthetic administration and ensure adequate hypnosis during surgery. Conventional monitoring techniques rely on clinical parameters and end-tidal anesthetic concentration, which may not accurately reflect cerebral activity. The Bispectral Index (BIS) is an electroencephalography-based monitoring tool that provides objective assessment of anesthetic depth and may allow more precise titration of inhalational anesthetic agents. Aim: To evaluate the effect of BIS-guided monitoring on sevoflurane consumption per hour during low-flow anesthesia compared with conventional monitoring techniques. Methodology: This prospective randomized controlled trial was conducted in the Department of Anaesthesiology at ESIC Medical College and Hospital, Hyderabad, over a period of one year. A total of 150 patients aged 18–60 years with ASA physical status I–II scheduled for elective surgeries under general anesthesia were enrolled and randomly allocated into two groups of 75 each. In both groups, anesthesia was maintained using a low-flow technique with fresh gas flow of 1 L/min and sevoflurane as the inhalational agent. In the BIS group, anesthetic depth was monitored using BIS and sevoflurane concentration was titrated to maintain BIS values between 40 and 60. In the conventional monitoring group, anesthetic depth was guided by end-tidal anesthetic concentration and minimum alveolar concentration values. The primary outcome was mean sevoflurane consumption per hour (ml/h). Secondary outcomes included intraoperative haemodynamic parameters, recovery profile in terms of time to eye opening, extubation time, and Modified Aldrete Score, and incidence of intraoperative awareness. Statistical analysis was performed using SPSS software with a significance level of p < 0.05. Results: The mean sevoflurane consumption per hour was significantly lower in the BIS group (12.4 ± 3.1 ml/h) compared with the conventional monitoring group (20.3 ± 4.2 ml/h; p < 0.001). Recovery was significantly earlier in the BIS group, with shorter time to eye opening (7.8 ± 2.1 minutes vs 11.6 ± 3.2 minutes) and earlier extubation (8.2 ± 2.6 minutes vs 12.9 ± 3.8 minutes) compared with the conventional group. The Modified Aldrete Score at 10 minutes was also higher in the BIS group. Intraoperative haemodynamic parameters remained stable and comparable between the two groups. No patient in the BIS group experienced intraoperative awareness, whereas one patient (1.3%) in the conventional group reported possible awareness. Conclusion: BIS-guided monitoring during low-flow anesthesia significantly reduces sevoflurane consumption per hour and improves postoperative recovery profile without compromising haemodynamic stability or increasing the risk of intraoperative awareness. BIS monitoring therefore represents a valuable tool for optimizing anesthetic drug administration and enhancing perioperative patient outcomes.

Background and Aims:In India, depth of anaesthesia monitoring with processed electroencephalogram (pEEG) is not routinely implemented. During volatile-based anaesthesia, end-tidal anaesthetic gas concentrations and age-adjusted minimum alveolar concentration values are widely accepted surrogates of anaesthetic depth. However, these measures do not directly reflect cortical activity, and no equivalent objective surrogate exists during total intravenous anaesthesia (TIVA). pEEG monitoring provides a direct assessment of cerebral activity and may support optimised anaesthetic titration, particularly in TIVA and other high-risk scenarios. The primary objective of this Delphi consensus was to develop expert-based, India-specific recommendations for the use of pEEG-based indices in intra-operative anaesthesia practice.Methods:A modified Delphi approach was employed with 15 anaesthesiology experts (13 Indian and 2 international). A Preferred Reporting Items for Systematic Reviews and Meta-analyses-based literature review, covering studies from 2016 to 2025, was conducted to develop 27 draft statements across 10 themes, including indications, target ranges, interpretation, and integration of pEEG with existing monitoring. Through structured iterative rounds involving a steering committee meeting (March 2025), and two rounds of advisory board (May 2025), the statements were revised, eliminated, or accepted based on high (≥80%), moderate (60–80%), or low (<60%) consensus.Results:Of the 27 initial statements, 19 achieved consensus and were included in the final statements. The statements spanned key clinical domains, including the need for depth of anaesthesia monitoring, role of pEEG-based indices, clinical benefits, indications based on anaesthetic techniques (TIVA and inhalational anaesthesia), patient characteristics, surgical context, and practical usage guidance, including target ranges and interpretation. Overall, the consensus supports the use of pEEG monitoring as an adjunct to optimise anaesthetic delivery, reduce drug consumption, and improve recovery profiles, particularly in high-risk and TIVA settings.Conclusion:This Delphi-based consensus provides a clinically relevant framework for integrating pEEG monitoring into anaesthesia practice in India. These recommendations aim to support personalised anaesthetic titration, enhance patient safety, and align peri-operative care with evolving global standards while accounting for local practice variability.

Alterations in excitation/inhibition (E/I) balance, involving both inhibitory and excitatory signaling, have been implicated in the pathophysiology of autism spectrum disorder (ASD). Volatile anesthetics, including sevoflurane, act on multiple molecular and network targets, and anesthetic sensitivity may therefore differ in ASD. This study investigated whether sevoflurane sensitivity is altered in BTBR T+Itpr3tf/J (BTBR) mice, a widely used mouse model of ASD. Sevoflurane sensitivity was compared between BTBR mice and C57BL/6J (B6) control mice using behavioral and electroencephalographic (EEG) analyses. The minimum alveolar concentration required to abolish nociceptive responses (MACsevo) and the sevoflurane concentration associated with recovery of the righting reflex (RRsevo) were measured. Dose-dependent EEG changes, including burst suppression and theta power distribution, were also evaluated. MACsevo did not differ significantly between BTBR and B6 mice. However, RRsevo was significantly lower in BTBR mice (1.10 ± 0.10%) compared with B6 mice (1.65 ± 0.13%; p < 0.001). EEG analyses demonstrated that burst suppression occurred at lower sevoflurane concentrations in BTBR mice (2.0%) than in B6 mice (2.4%). In addition, topographical mapping revealed distinct theta power dynamics between the two strains during anesthesia. BTBR mice exhibit increased sensitivity to sevoflurane during emergence from anesthesia and show distinct EEG patterns compared with control mice. These findings suggest altered anesthetic responsiveness in a mouse model of ASD and support the possibility that network-level neurophysiological differences may influence anesthetic responses. Further studies are needed to clarify whether similar alterations are present across other ASD models and human ASD populations.

Perioperative neurocognitive disorder is a serious complication, in which general anaesthesia is a major contributor. Disruption of neuronal Ca2+ homeostasis, potentially involving store-operated Orai1 channels, is one proposed mechanism. The study investigated the role of Orai1 channels in inhibitory neurons. Behavioural data before and 1h after general anaesthesia (1 minimum alveolar concentration (MAC) for 30 min) were compared in wild-type (WT) and knockout (KO) mice, in which Orai1 was specifically deleted in inhibitory interneurons. To examine the underlying mechanisms, electrophysiological studies were performed using brain slices and hippocampal neuroinflammation was assessed by enzyme-linked immunosorbent assay. The success rate of the Y-maze test significantly decreased after sevoflurane anaesthesia in WT but not in KO mice, with similar results after isoflurane and longer duration sevoflurane (1h) anaesthesia. Hippocampal long-term potentiation showed a similar reduction after sevoflurane in WT but not in KO mice. Whole-cell patch-clamp recordings from CA1 interneurons revealed that the sevoflurane-induced increase in the frequency of spontaneous inhibitory postsynaptic currents in WT was diminished by tetrodotoxin, whereas no significant increase was observed in KO mice. Hippocampal TNFα levels were significantly higher after sevoflurane in WT but not in KO mice. Pre-administration of an Orai1 channel inhibitor showed a similar decrease in the Y-maze test after sevoflurane anaesthesia. Store-operated Orai1 channels in inhibitory neurons could play a critical role in delayed recovery following general anaesthesia, potentially by regulating action potential generation. Pharmacological inhibition of the channels may prevent perioperative neurocognitive disorder.

Testicular torsion, a urological emergency, can lead to testicular dysfunction or infertility due to ischaemia-reperfusion injury, yet current interventions remain limited. Although sevoflurane, an inhaled anaesthetic, has shown organ-protective effects against ischaemia-reperfusion injury in the heart and brain, its role in testicular ischaemia-reperfusion injury is unclear. A rat model of acute (720° with 3-h ischaemia/3-h reperfusion) and long-term (720° with 1-h ischaemia/3-day reperfusion) testicular ischaemia-reperfusion injury was set up to explore the protective effects and mechanisms of preconditioning and post-conditioning with sevoflurane. 1.5 minimum alveolar concentration (MAC) sevoflurane for 30 min significantly mitigated acute ischaemia-reperfusion injury, as shown by reductions in bilateral testicular oedema, oxidative stress (lower MDA levels), inflammation (decreased TNF-α, IL-6) and apoptosis (reduced Bax/Bcl-2 ratio). Long-term, it alleviated testicular atrophy and enhanced sperm count, motility and spermatogenesis. Mechanistically, sevoflurane activated ERK1/2 phosphorylation in the RISK pathway, with its protective effects being abolished by the ERK1/2 inhibitor U0126. Sevoflurane exerts acute and chronic protective effects against bilateral testicular ischaemia-reperfusion injury via ERK1/2 signalling and offers a novel pharmacological strategy to mitigate complications following de-torsion.

Parasympathetic tone, cardiovascular variables, and behavioral alterations in conscious horses before and after castration and during anesthesia: A pilot study.

Neuraxial anaesthesia is preferred for Caesarean deliveries, but general anaesthesia is used in situations such as emergencies, contraindications to neuraxial anaesthesia, or anticipated complex deliveries. Although previous research has examined how the duration of fetal general anaesthesia exposure affects neonatal outcomes, the total dose of general anaesthesia has not been studied. The primary aim was to determine the association, if any, between the general anaesthesia dose and 5-min neonatal Apgar scores. We hypothesised that greater maternal exposure to general anaesthesia would be associated with lower neonatal 5-min Apgar scores. This retrospective single centre cohort study evaluated the association between total maternal general anaesthesia dose and 5-min Apgar scores among neonates born via planned Caesarean delivery under general anaesthesia between January 2013 and March 2022. Total general anaesthesia dose was quantified using the area under the curve of effective minimum alveolar concentration (EMAC-AUC) from general anaesthesia induction to neonatal delivery (T). Multivariable logistic regression adjusted for maternal age, gestational age, and maternal hypertension. Maternal blood pressure was quantified by the area under the curve for mean arterial pressure <80 mm Hg (MAP80AUC). Analysis included 101 neonates born via planned Caesarean delivery under maternal general anaesthesia. Every 5-MAC-minute increase in EMAC-AUC was associated with a 10% increase in the adjusted odds of a 5-min Apgar score of <7 (odds ratio, 1.10; 95% confidence interval, 1.05-1.22; P <0.001). However, this association was not significant after adjusting for maternal MAP80AUC (odds ratio, 1.05; 95% confidence interval, 1.00-1.16; P=0.177). In this cohort of preterm, late preterm, and term neonates delivered via planned CD or Caesarean hysterectomy, total general anaesthetic dose was statistically associated with the 5-min Apgar score, although the clinical effect was modest. The attenuation of the EMAC-AUC association after adjusting for MAP80AUC suggests that maternal hypotension may play an important explanatory role, although causality cannot be inferred. Maintaining mean arterial pressure >80 mm Hg may reduce the likelihood of low Apgar scores, although prospective studies are needed to confirm this relationship.

Background/Objectives: Volatile anesthetic dosing during cardiopulmonary bypass (CPB) is poorly standardized. We estimated the end-tidal sevoflurane (ETsevo) concentration required to maintain adequate anesthesia during CPB and investigated the effects of age and body temperature. Methods: This study is a PRISMA-compliant, PROSPERO-registered meta-analysis. PubMed, Embase, and the Cochrane Library were searched. Prospective studies of adults who underwent cardiac surgery with CPB and receiving sevoflurane were included. Primary outcome was mean ETsevo concentration when bispectral index (BIS) was 40-60. Three-level random-effects meta-analytic models with robust variance estimation were used to pool repeated measurements within studies. Age and body temperature were then examined as study-level moderators. Risk of bias was determined using ROBINS-I. Results: Five studies (n = 129) fulfilled the criteria. Pooled ETsevo during CPB was 0.88 vol% (95% confidence interval [CI] 0.29 to 1.46; p = 0.02) with substantial heterogeneity (I2 = 87.6%). Body temperature was not a significant moderator (difference 0.26 vol%; 95% CI -1.12 to 1.64; p = 0.27). Higher mean age was associated with lower ETsevo, evidenced by the finding that patients with a mean age of >62.0 years required 0.45 vol% less ETsevo (95% CI -0.78 to -0.13; p = 0.01), and sensitivity analysis revealed a 0.05 vol% decrease per additional year. Conclusions: To maintain BIS at 40-60 during CPB, the estimated ETsevo requirement is 0.88 vol% (minimum alveolar concentration 0.53-0.58 in patients in their 60s). Requirements decreased with age, and body temperature exerted no detectable effect.

Background: This study aimed to compare the effects of equipotent doses (one minimum alveolar concentration) of sevoflurane and desflurane on respiratory mechanics, haemodynamics and oxygenation in patients undergoing spinal surgery in the prone position. Methods: Fifty patients were randomised to receive either sevoflurane (n = 25) or desflurane (n = 25). Respiratory parameters (dynamic compliance (Cdyn); peak (Ppeak), mean (Pmean) and plateau (Pplateau) airway pressures; driving pressure (∆P); tidal volume; and dead space), haemodynamic parameters (heart rate (HR) and systolic, mean and diastolic arterial pressures) and oxygenation parameters were recorded intraoperatively at baseline, after prone positioning, during surgery, and after returning to the supine position. Results: Prone positioning led to significant increases in Ppeak and reductions in Cdyn in both groups (p &lt; 0.05). Although Ppeak, Pmean, Pplateau and ∆P fluctuated intraoperatively, no intergroup differences were detected (p &gt; 0.05). After returning to the supine position, respiratory mechanics approached baseline in both groups. Oxygenation (arterial oxygen pressure), ventilation (arterial carbon dioxide pressure), end-tidal carbon dioxide, and pH remained stable and comparable. Sevoflurane was associated with slightly greater decreases in arterial pressures, whereas HR was similar between groups. Conclusions: Both desflurane and sevoflurane maintained stable intraoperative respiratory mechanics, oxygenation, and haemodynamics in patients without pulmonary disease. Prone positioning increased Ppeak and decreased Cdyn similarly in both groups. Both agents appear safe for spinal surgery in the prone position. Clinical Trial Registration: This study was registered at ClinicalTrials.gov (NCT06118489).

BackgroundIntraoperative EEG provides a noninvasive window into cortical dynamics under anesthesia, but conventional spectral analysis cannot capture nonstationary modulation patterns linked to nociceptive processing. This study applied Holo‐Hilbert spectral analysis (HHSA) to characterize cross‐frequency modulation patterns in relation to the Surgical Pleth Index (SPI) during general anesthesia.MethodsFrontal EEG from 134 female patients undergoing gynecologic surgery was analyzed. Ten‐minute segments were first examined to define canonical modulation structures, followed by one‐minute epochs synchronized with SPI values to assess dynamic changes. HHSA decomposed each epoch into amplitude modulation patterns across carrier frequencies (1/64–64 Hz). Group comparisons between pain and no‐pain epochs were performed using t‐tests with Bonferroni correction. A linear mixed‐effects model evaluated the effects of SPI, minimum alveolar concentration (MAC), heart rate (HR), and mean arterial pressure (NIBP‐m) on alpha‐band modulation (8–16‐Hz carrier modulated by 3–8‐Hz amplitude).ResultsHHSA revealed two dominant cross‐frequency interactions within the alpha‐carrier band (8–16 Hz): one modulated by 3–6‐Hz (high‐delta to theta) and another by 1–2‐Hz (low‐delta) oscillations, indicating layered modulation under anesthesia. During nociceptive states (SPI > 60), modulation power increased in the alpha and high‐delta bands, while theta and low‐delta modulation weakened. Alpha‐band modulation power rose with SPI and declined with MAC.ConclusionsHHSA revealed distinct cross‐frequency modulation patterns reflecting the cortical balance between nociception and analgesia. Alpha‐band modulation serves as a physiologically grounded EEG marker for individualized nociception monitoring under general anesthesia.

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Previous studies found that low-flow sevoflurane anesthesia in respiratory mechanics is comparable with higher flow during laparoscopic surgery, but metabolic flow has not been studied adequately. The study compares the effect of metabolic flow with the low-flow technique on respiratory mechanics during laparoscopic procedures. Sixty adult patients of either sex, American Society of Anesthesiologists physical status I-II scheduled for laparoscopic surgery of <3 h were randomly assigned into group M: metabolic (n = 30) and group L: low-flow anesthesia (n = 30). Both groups received fresh gas flow (FGF) of 6 L/min of oxygen, air, and sevoflurane until they attained a minimum alveolar concentration (MAC) of 1; FGF was changed to 1 L/min in group L. In group M, the FGF was changed to estimate the metabolic flow of oxygen (Brody's formula) plus the leak detected during the pre-use check. The delivered FiO2 was maintained above 50%, and The dial concentration of sevoflurane was adjusted to maintain a target MAC-1 throughout the procedure in both groups. The primary objective was to compare postoperative forced vital capacity (FVC) after achieving a Modified Aldrete Score of ≥9. The secondary objectives included comparing arterial blood gas (ABG) parameters, hemodynamic parameters, and sevoflurane consumption. There was no statistically significant difference in the FVC, ABG, and hemodynamic parameters between the two groups pre- (T1) and postoperatively (T2, T3, T4). There was a statistically significant decrease in sevoflurane consumption (P = <0.001) in the metabolic-flow group. The effects of metabolic-flow anesthesia on pulmonary mechanics and gas exchange were similar to those of the low-flow anesthesia technique.

This study was implemented to reveal the expression and the clinical correlation of matrix metalloproteinase 2 (MMP2) in patients with interstitial lung disease ILD. This clinical study was conducted with 72 subjects (37 males, 35 females; mean age: 61.18(±13.95)years). They were divided into fibrotic group and non-fibrotic group based on whether the images showed fibrotic ILD. MMP2 concentrations in patients’ serum and bronchoalveolar lavage fluid balf were detected by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to assess spatial expression of MMP2 and denatured collagen in fibrotic lung tissues. Serum and alveolar lavage fluid concentrations of MMP2 were significantly higher in the fibrosis group than in the non-fibrosis group. MMP2 level in serum was negatively correlated with forced expiratory volume in the first second (FEV1), total lung volume (TLC), residual volume (RV), and lung diffusing capacity for carbon monoxide (DLCO). Pearson statistical analysis revealed that MMP2 expression was positively related to leucocyte, carbohydrate antigen125 (CA125) and carcinoembryonic antigen(CEA). Fluorescently labeled collagen hybridizing peptide CHP was used to specifically localize degenerative collagen in the lung tissues of five lung transplantation patients, immunofluorescence results showed that MMP2 and CHP were co-localized and highly expressed in fibrosis tissue. Expressions of MMP2 is significantly increased in patients with fibrotic interstitial lung disease. Higher expression of MMP2 implies more severe impairment of lung function, suggests that MMP2 could be used as potential biomarker for assessing severity of ILD.

ACE Question: Factors in Minimum Alveolar Concentration

Volatile anesthetics representa relevant yet largely avoidable source of greenhouse gas emissions in the healthcare system. In Germany, their use accounts for approximately69 kt of CO2 equivalents annually. While desflurane is used in only about3% of inhalation anesthesia procedures, it is responsible for more than50% of the associated emissions due to its extremely high global warming potential. Modelling studies indicate that complete substitution of desflurane with sevoflurane would reduce total emissions by approximately53%; replacing isoflurane as well would increase the reduction to65%. From a clinical perspective, desflurane offers no proven advantage over sevoflurane with respect to patient safety or postoperative outcomes. Isoflurane likewise shows no clinical superiority. This creates substantial scope for substitution without compromising quality of care. Under minimum alveolar concentration (MAC)-adjusted conditions, desflurane causes an approximately34-fold higher global warming per anesthesia hour than sevoflurane. The contrast is even greater when compared to total intravenous anesthesia (TIVA). Of particular relevance is the short-term climate impact. Due to its high radiative efficiency, desflurane exerts most of its warming effect within a few decades, precisely the critical period up to2050. In addition, volatile anesthetics contribute to environmental contamination with persistent perfluoroalkyl and polyfluoroalkyl substances (PFAS), posing potential long-term risks to ecosystems and human health. Eliminating desflurane requires no new infrastructure, is economically rational and can be implemented immediately. It hence represents a rare opportunity in the healthcare system to achieve rapid and substantial emission reductions through a simple clinical decision, while maintaining patient safety and quality of care.

Volatile anesthetics representa relevant yet largely avoidable source of greenhouse gas emissions in the healthcare system. In Germany, their use accounts for approximately69 kt of CO2 equivalents annually. While desflurane is used in only about3% of inhalation anesthesia procedures, it is responsible for more than50% of the associated emissions due to its extremely high global warming potential. Modelling studies indicate that complete substitution of desflurane with sevoflurane would reduce total emissions by approximately53%; replacing isoflurane as well would increase the reduction to65%. From a clinical perspective, desflurane offers no proven advantage over sevoflurane with respect to patient safety or postoperative outcomes. Isoflurane likewise shows no clinical superiority. This creates substantial scope for substitution without compromising quality of care. Under minimum alveolar concentration (MAC)-adjusted conditions, desflurane causes an approximately34-fold higher global warming per anesthesia hour than sevoflurane. The contrast is even greater when compared to total intravenous anesthesia (TIVA). Of particular relevance is the short-term climate impact. Due to its high radiative efficiency, desflurane exerts most of its warming effect within a few decades, precisely the critical period up to2050. In addition, volatile anesthetics contribute to environmental contamination with persistent perfluoroalkyl and polyfluoroalkyl substances (PFAS), posing potential long-term risks to ecosystems and human health. Eliminating desflurane requires no new infrastructure, is economically rational and can be implemented immediately. It hence represents a rare opportunity in the healthcare system to achieve rapid and substantial emission reductions through a simple clinical decision, while maintaining patient safety and quality of care.

This study aimed to compare two different sevoflurane formulations (Sevones® and Sevorane®) under low-flow anesthesia in terms of time to 1 Minimum Alveolar Concentration (MAC), agent consumption and uptake, emergence profile, and anesthesia-related complications. This retrospective observational study was conducted at Sakarya University Training and Research Hospital, Türkiye. A total of 89 female patients undergoing elective gynecologic surgery under general anesthesia with low-flow sevoflurane (≤ 1L/min) were included. Patients received either Sevones® (n = 46) or Sevorane® (n = 43). Standardized anesthetic induction with propofol and rocuronium was followed by low-flow sevoflurane maintenance. The primary outcome was time to reach 1 MAC. Secondary outcomes included agent consumption and uptake during induction and maintenance, emergence characteristics, intraoperative hemodynamic and PSI trends, and anesthesia-related complications. Statistical comparisons were performed using t-test, Mann-Whitney U, and chi-square tests as appropriate. Time to reach 1 MAC was similar between Sevones® and Sevorane® groups (198.26 ± 41.1s vs. 205.63 ± 51.2s; p = 0.455). Agent consumption and uptake during induction were comparable. Total agent uptake was significantly higher in the Sevones® group (16.63 ± 5.32 mL vs. 13.49 ± 7.45 mL; p = 0.024), while total agent consumption showed no significant difference. Emergence times, PSI trends, and complication rates were similar between groups. Both Sevones® and Sevorane® demonstrated comparable pharmacokinetic and pharmacodynamic profiles under low-flow anesthesia. The findings support their safe and effective use during elective gynecologic surgery. Not applicable.

Abstract Background: Sevoflurane is usually administered according to the minimum alveolar concentration. Age is an important variable affecting the minimum alveolar concentration and it should be kept in mind that two individuals of the same chronologic age may have different metabolic ages. The purpose of this study is to evaluate the relationship between metabolic age, chronological age and sevoflurane consumption in patients with sufficient depth of anesthesia. Methods: Bioelectrical impedance analysis of 79 patients aged 18-65 years, chronological age, metabolic age and other metabolic parameters were recorded. To standardize the relationship between sevoflurane consumption and chronological age and metabolic age, patients were divided into three groups using the percentage age difference formula; Group A; age difference 11.7%. Results: The study included 79 patients, 29.1% of whom were women. The mean chronologic and metabolic ages of the patients were 31.29 ± 11.9 and 30.42 ± 12.89 years, respectively. A significant difference was seen between chronologic and metabolic age and total sevoflurane consumption (p=0.006; p=0.007) and a weak negative correlation was observed (r= -0.304; r=-0.301). When the sevoflurane consumption amounts of the groups were compared, a notable difference was observed among the three groups (p

This study compared automatic gas control (AGC) mode with manual minimal-flow and manual medium-flow techniques in elective breast surgery, evaluating sevoflurane consumption, cost, hemodynamics, and recovery. Following ethics approval, 90 American Society of Anaesthesiologists I-II patients (age 18-65 years) undergoing elective breast surgery were randomized to AGC mode (Group AGC, n = 30), manual minimal-flow control (Group ManCo, n = 30), or manual medium-flow control (Group ModFA, n = 30). All received standard induction after preoxygenation, with maintenance via sevoflurane and remifentanil infusion in a mixture of oxygen and medical air. After reaching a minimum alveolar concentration of 1.0, sevoflurane was adjusted to maintain a bispectral index of 40-60. Mean arterial pressure (MAP), heart rate, peripheral capillary oxygen saturation, bispectral index, inspired sevoflurane fractions and expired sevoflurane fraction, end-tidal carbon dioxide, temperature, and instantaneous sevoflurane consumption were recorded pre-induction and every 15 minutes. Extubation time, recovery time, surgery duration, and total anaesthesia time were documented. Total sevoflurane consumption and cost were calculated postoperatively. Sevoflurane consumption and related costs were significantly lower in Group AGC versus Groups ManCo and ModFA (both P <0.001) and lower in Group ManCo than in Group ModFA (P <0.001). MAP and recovery times did not differ significantly among groups (P >0.05). Pre-extubation temperature was higher in Group AGC compared to Group ManCo (P=0.014) and Group ModFA (P=0.002). Extubation time was longer in Group ManCo versus Groups AGC and ModFA (P <0.001). AGC mode significantly reduces sevoflurane consumption and cost compared to both manual minimal-flow and manual medium-flow techniques, without adversely affecting hemodynamics or recovery.