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Background: Sedatives are administered to 85% of intensive care unit (ICU) patients. The most commonly used sedatives are intravenous benzodiazepines and propofol. These agents are associated with over-sedation in 40 to 60% of patients, which can lead to prolonged intubation, delirium and drug-induced hypotension. Evidence is increasing that volatile anesthetic agents are associated with faster extubation times, improved cardiovascular stability with no end-organ toxicity in comparison to our standard intravenous agents for short-term critical care sedation. Use of volatile agents within the ICU is a novel technique using a specialized delivery and scavenging system, which requires staff training and cultural acceptance. This pilot randomized controlled trial aims to assess the safety and feasibility of delivering volatile agents for long-term patient sedation in the ICU with limited or no experience of this technique., Methods/design: This is a prospective multicenter pragmatic pilot RCT that is blinded to the data analyst. This study aims to recruit 60 adult ICU patients requiring mechanical ventilation and sedation for more than 48 h. Patients will be randomized 2:1 to receive inhaled isoflurane (40 patients) or intravenous midazolam and/or propofol (20 patients) sedation. Sedation is titrated to a targeted Sedation Analgesia Score (SAS) using an explicit sedation-analgesia algorithm until extubation or tracheostomy. Primary safety and feasibility outcomes will assess atmospheric volatile concentration levels and adherence to our sedation-analgesia protocol. Secondary outcomes include time to extubation, duration of ventilation, quality of sedation, delirium, vasoactive drug support, length of stay, serum fluoride levels and mortality., Discussion: This pilot project will serve as the basis for a larger RCT that will be powered for important clinical outcomes., Trial Registration: ClinicalTrials.gov, NCT01983800 (registration date 2 July 2013).

Background: We conducted a prospective controlled clinical trial of the effect of isocapnic hyperpnoea (IH) on the times-to-recovery milestones in the operating room (OR) and postanesthetic care unit (PACU) after 1.5 to 3 hours of isoflurane anesthesia., Methods: Thirty ASA grade I-III patients undergoing elective gynecological surgery were randomized at the end of surgery to either IH or the conventional recovery (control). Six patients with duration of anesthesia of <90 minutes were excluded from the analysis. The anesthesia protocol included propofol, fentanyl, morphine, rocuronium, and isoflurane in air/O(2). Unpaired t tests and analyses of variance were used to test for differences in times-to-recovery indicators between the two groups., Results: The durations of anesthesia in IH and control groups were 140.8 + or - 32.7 and 142 + or - 55.6 minutes, respectively (P = 0.99). The time to extubation was much shorter in the IH group than in the control group (6.6 + or - 1.6 (SD) vs. 13. 6 + or - 3.9 minutes, respectively; P < 0.01). The IH group also had shorter times to eye opening (5.8 + or - 1.3 vs. 13.7 + or - 4.5 minutes; P < 0.01), eligibility for leaving the OR (8.0 + or - 1.7 vs. 17.4 + or - 6.1 minutes; P < 0.01), and eligibility for PACU discharge (74.0 + or - 16.5 vs. 94.5 + or - 14.7 minutes; P < 0.01). There were no differences in other indicators of recovery., Conclusion: IH accelerates recovery after 1.5 to 3 hours of isoflurane anesthesia and shortens OR and PACU stay.

Brain injured patients often need deep sedation to prevent or treat increased intracranial pressure. The mainly used IV sedatives have side effects and/or high context-sensitive half-lives, limiting their use. Inhalative sedatives have comparatively minor side effects and a brief context-sensitive half-life. Despite the theoretical advantages, evidence in this patient group is lacking. A Germany-wide survey with 21 questions was conducted to find out how widespread the use of inhaled sedation is. An invitation for the survey was sent to 226 leaders of intensive care units (ICU) treating patients with brain injury as listed by the German Society for Neurointensive Care. Eighty-nine participants answered the questionnaire, but not all items were responded to, which resulted in different absolute counts. Most of them (88%) were university or high-level hospital ICU leaders and (67%) were leaders of specialized neuro-ICUs. Of these, 53/81 (65%) use inhalative sedation, and of the remaining 28, 17 reported interest in using this kind of sedation. Isoflurane is used by 43/53 (81%), sevoflurane by 15/53 (28%), and desflurane by 2. Hypotension and mydriasis are the most common reported side effects (25%). The presented survey showed that inhalative sedatives were used in a significant number of intensive care units in Germany to treat severely brain-injured patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sedation is fundamental to the management of patients in the intensive care unit (ICU). Its indications in the ICU are vast, including the facilitating of mechanical ventilation, permitting invasive procedures, and managing anxiety and agitation. Inhaled sedation with halogenated agents, such as isoflurane or sevoflurane, is now feasible in ICU patients using dedicated devices/systems. Its use may reduce adverse events and improve ICU outcomes compared to conventional intravenous (IV) sedation in the ICU. This review examined the effectiveness of inhalational sedation using the anesthetic conserving device (ACD) compared to standard IV sedation for adult patients in ICU and highlights the technical aspects of its functioning. METHODS: We searched the PubMed, Cochrane Central Register of Controlled Trials, The Cochrane Library, MEDLINE, Web of Science, and Sage Journals databases using the terms "anesthetic conserving device," "Anaconda," "sedation" and "intensive care unit" in randomized clinical studies that were performed between 2012 and 2022 and compared volatile sedation using an ACD with IV sedation in terms of time to extubation, duration of mechanical ventilation, and lengths of ICU and hospital stay. RESULTS: Nine trials were included. Volatile sedation (sevoflurane or isoflurane) administered through an ACD shortened the awakening time compared to IV sedation (midazolam or propofol). CONCLUSION: Compared to IV sedation, volatile sedation administered through an ACD in the ICU shortened the awakening and extubation times, ICU length of stay, and duration of mechanical ventilation. More clinical trials that assess additional clinical outcomes on a large scale are needed. [ABSTRACT FROM AUTHOR]

Introduction: In patients with severe aneurysmal subarachnoid hemorrhage (SAH) deep sedation is often used early in the course of the disease in order to control brain edema formation and thus intracranial hypertension. However, some patients do not reach an adequate sedation depth despite high doses of common intravenous sedatives. Balanced sedation protocols incorporating lowdose volatile isoflurane administration might improve insufficient sedation depth in these patients. Methods: We retrospectively analyzed ICU patients with severe aneurysmal SAH who received isoflurane in addition to intravenous anesthetics in order to improve insufficient sedation depth. Routinely recorded data from neuromonitoring, laboratory and hemodynamic parameters were compared before and up to 6 days after initiation of isoflurane. Results: Sedation depth measured using the bispectral index improved in thirty-six SAH patients (-15.16; p = 0.005) who received additional isoflurane for a mean period of 9.73 ± 7.56 days. Initiation of isoflurane sedation caused a decline in mean arterial pressure (-4.67 mmHg; p = 0.014) and cerebral perfusion pressure (-4.21 mmHg; p = 0.013) which had to be balanced by increased doses of vasopressors. Patients required increased minute ventilation in order to adjust for the increase in PaCO2 (+2.90 mmHg; p < 0.001). We did not detect significant increases in mean intracranial pressure. However, isoflurane therapy had to be terminated prematurely in 25% of the patients after a median of 30 h due to episodes of intracranial hypertension or refractory hypercapnia. Discussion: A balanced sedation protocol including isoflurane is feasible for SAH patients experiencing inadequately shallow sedation. However, therapy should be restricted to patients without impaired lung function, hemodynamic instability and impending intracranial hypertension. [ABSTRACT FROM AUTHOR]

Devices used to deliver inhaled sedation increase dead space ventilation. We therefore compared ventilatory effects among isoflurane sedation via the Sedaconda ACD-S (internal volume: 50 mL), isoflurane sedation via the Sedaconda ACD-L (100 mL), and propofol sedation with standard mechanical ventilation with heat and moisture exchangers (HME). This is a substudy of a randomized trial that compared inhaled isoflurane sedation via the ACD-S or ACD-L to intravenous propofol sedation in 301 intensive care patients. Data from the first 24 h after study inclusion were analyzed using linear mixed models. Primary outcome was minute ventilation. Secondary outcomes were tidal volume, respiratory rate, arterial carbon dioxide pressure, and isoflurane consumption. In total, 151 patients were randomized to propofol and 150 to isoflurane sedation; 64 patients received isoflurane via the ACD-S and 86 patients via the ACD-L. While use of the ACD-L was associated with higher minute ventilation (average difference (95% confidence interval): 1.3 (0.7, 1.8) L/min, p < 0.001), higher tidal volumes (44 (16, 72) mL, p = 0.002), higher respiratory rates (1.2 (0.1, 2.2) breaths/min, p = 0.025), and higher arterial carbon dioxide pressures (3.4 (1.2, 5.6) mmHg, p = 0.002), use of the ACD-S did not significantly affect ventilation compared to standard mechanical ventilation and sedation. Isoflurane consumption was slightly less with the ACD-L compared to the ACD-S (−0.7 (−1.3, 0.1) mL/h, p = 0.022). The Sedaconda ACD-S compared to the ACD-L is associated with reduced minute ventilation and does not significantly affect ventilation compared to a standard mechanical ventilation and sedation setting. The smaller ACD-S is therefore the device of choice to minimize impact on ventilation, especially in patients with a limited ability to compensate (e.g., COPD patients). Volatile anesthetic consumption is slightly higher with the ACD-S compared to the ACD-L. [ABSTRACT FROM AUTHOR]

Inhaled sedation was recently approved in Europe as an alternative to intravenous sedative drugs for intensive care unit (ICU) sedation. The aim of this narrative review was to summarize the available data from the literature published between 2005 and 2023 in terms of the efficacy, safety, and potential clinical benefits of inhaled sedation for ICU mechanically ventilated patients. The results indicated that inhaled sedation reduces the time to extubation and weaning from mechanical ventilation and reduces opioid and muscle relaxant consumption, thereby possibly enhancing recovery. Several researchers have reported its potential cardio-protective, anti-inflammatory or bronchodilator properties, alongside its minimal metabolism by the liver and kidney. The reflection devices used with inhaled sedation may increase the instrumental dead space volume and could lead to hypercapnia if the ventilator settings are not optimal and the end tidal carbon dioxide is not monitored. The risk of air pollution can be prevented by the adequate scavenging of the expired gases. Minimizing atmospheric pollution can be achieved through the judicious use of the inhalation sedation for selected groups of ICU patients, where the benefits are maximized compared to intravenous sedation. Very rarely, inhaled sedation can induce malignant hyperthermia, which prompts urgent diagnosis and treatment by the ICU staff. Overall, there is growing evidence to support the benefits of inhaled sedation as an alternative for intravenous sedation in ICU mechanically ventilated patients. The indication and management of any side effects should be clearly set and protocolized by each ICU. More randomized controlled trials (RCTs) are still required to investigate whether inhaled sedation should be prioritized over the current practice of intravenous sedation. [ABSTRACT FROM AUTHOR]

Background and objectives: The coronavirus disease 2019 (COVID-19) pandemic and the shortage of intravenous sedatives has led to renewed interest in inhaled sedation for patients with acute respiratory distress syndrome (ARDS). We hypothesized that inhaled sedation would be associated with improved clinical outcomes in COVID-19 ARDS patients. Methods: Retrospective international study including mechanically ventilated patients with COVID-19 ARDS who required sedation and were admitted to 10 European and US intensive care units. The primary endpoint of ventilator-free days through day 28 was analyzed using zero-inflated negative binomial regression, before and after adjustment for site, clinically relevant covariates determined according to the univariate results, and propensity score matching. Results: A total of 196 patients were enrolled, 78 of whom died within 28 days. The number of ventilator-free days through day 28 did not differ significantly between the patients who received inhaled sedation for at least 24 h (n = 111) and those who received intravenous sedation only (n = 85), with medians of 0 (interquartile range [IQR] 0–8) and 0 (IQR 0–17), respectively (odds ratio for having zero ventilator-free days through day 28, 1.63, 95% confidence interval [CI], 0.91–2.92, p = 0.10). The incidence rate ratio for the number of ventilator-free days through day 28 if not 0 was 1.13 (95% CI, 0.84–1.52, p = 0.40). Similar results were found after multivariable adjustment and propensity matching. Conclusion: The use of inhaled sedation in COVID-19 ARDS was not associated with the number of ventilator-free days through day 28. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic has increased the number of patients in ICUs leading to a worldwide shortage of the intravenous sedative agents obligating physicians to find alternatives including inhaled sedation. Inhaled sedation in French ICU has been previously explored in 2019 (VOL'ICU study). This survey was designed to explore the use of inhaled sedation two years after our first survey and to evaluate how the COVID-19 pandemic has impacted the use of inhaled sedation. Methods: We designed a national survey, contacting medical directors of French ICUs between June and October 2021. Over a 50-item questionnaire, the survey covered the characteristics of the ICU, data on inhaled sedation, and practical aspects of inhaled ICU sedation for both COVID-19 and non-COVID-19 patients. Answers were compared with the previous survey, VOL'ICU. Results: Among the 405 ICUs contacted, 25% of the questionnaires were recorded. Most ICU directors (87%) knew about the use of inhaled ICU sedation and 63% of them have an inhaled sedation's device in their unit. The COVID-19 pandemic increased the use of inhaled sedation in French ICUs. The main reasons said by the respondent were "need for additional sedative" (62%), "shortage of intravenous sedatives" (38%) and "involved in a clinical trial" (30%). The main reasons for not using inhaled ICU sedation were "device not available" (76%), "lack of familiarity" (60%) and "no training for the teams" (58%). More than 70% of respondents were overall satisfied with the use of inhaled sedation. Almost 80% of respondents stated that inhaled sedation was a seducing alternative to intravenous sedation for management of COVID-19 patients. Conclusion: The use of inhaled sedation in ICU has increased fastly in the last 2 years, and is frequently associated with a good satisfaction among the users. Even if the COVID-19 pandemic could have impacted the widespread use of inhaled sedation, it represents an alternative to intravenous sedation for more and more physicians. [ABSTRACT FROM AUTHOR]

Low-dose isoflurane stimulates spontaneous breathing. We, therefore, tested the hypothesis that isoflurane compared to propofol sedation for at least 48 h is associated with increased respiratory drive in intensive care patients after sedation stop. All patients in our intensive care unit receiving at least 48 h of isoflurane or propofol sedation in 2019 were included. The primary outcome was increased respiratory drive over 72 h after sedation stop, defined as an arterial carbon dioxide pressure below 35 mmHg and a base excess more than −2 mmol/L. Secondary outcomes were acid–base balance and ventilatory parameters. We analyzed 64 patients, 23 patients sedated with isoflurane and 41 patients sedated with propofol. Patients sedated with isoflurane were about three times as likely to show increased respiratory drive after sedation stop than those sedated with propofol: adjusted risk ratio [95% confidence interval]: 2.9 [1.3, 6.5], p = 0.010. After sedation stop, tidal volumes were significantly greater and arterial carbon dioxide partial pressures were significantly lower, while respiratory rates did not differ in isoflurane versus propofol-sedated patients. In conclusion, prolonged isoflurane use in intensive care patients is associated with increased respiratory drive after sedation stop. Beneficial effects of isoflurane sedation on respiratory drive may, thus, extend beyond the actual period of sedation. [ABSTRACT FROM AUTHOR]

Desflurane, isoflurane and sevoflurane, three halogenated ethers, are commonly used inhaled anesthetics, both in the operating room and in the intensive care unit (ICU). The potency and dosage of these drugs is expressed by the MAC value (minimum alveolar concentration). Their interaction with hemoglobin and its affinity for oxygen, best described by the oxygen dissociation curve (ODC), has already been investigated, with conflicting results. Altered by many factors, the ODC can be shifted to the left or to the right, therefore increasing or decreasing hemoglobin oxygen (Hb-O2) affinity. In venous blood samples of 22 healthy participants (11 female, 11 male) ODC were measured with a high-throughput method in vitro. Blood samples were either exposed to control or to three different concentrations of desflurane, isoflurane or sevoflurane prior to and during measurements (low, medium and high corresponding to MAC 0.5, MAC 1.0 and MAC 2.0). With increasing concentrations from control to medium, desflurane and isoflurane significantly decreased Hb-O2 affinity by shifting the ODC to the right (p = 0.016 and p < 0.001) but sevoflurane showed no effects. When further increasing concentrations from medium to high, all three inhaled anesthetics shifted the ODC back to the left (p < 0.001). Comparing only controls to high concentrations, a significant increase in Hb-O2 affinity for desflurane (p = 0.005) and sevoflurane (p < 0.001) was detected. Our study shows a varying effect at different doses of inhaled anesthetics on Hb-O2 affinity. While the underlying mechanisms remain unclear, these results show an effect which needs to be further investigated to determine if patients undergoing anesthesia may potentially benefit or get disadvantage from this slightly increased (e.g. impaired pulmonary oxygen uptake), or decreased Hb-O2 affinity (e.g. arterial vascular disease). Trial registration: This study is registered with clinicaltrials.gov (NCT04612270). [ABSTRACT FROM AUTHOR]

Neonatal anesthesia, while often essential for surgeries or imaging procedures, is accompanied by significant risks to redox balance in the brain due to the relatively weak antioxidant system in children. Oxidative stress is characterized by concentrations of reactive oxygen species (ROS) that are elevated beyond what can be accommodated by the antioxidant defense system. In neonatal anesthesia, this has been proposed to be a contributing factor to some of the negative consequences (e.g., learning deficits and behavioral abnormalities) that are associated with early anesthetic exposure. In order to assess the relationship between neonatal anesthesia and oxidative stress, we first review the mechanisms of action of common anesthetic agents, the key pathways that produce the majority of ROS, and the main antioxidants. We then explore the possible immediate, short-term, and long-term pathways of neonatal-anesthesia-induced oxidative stress. We review a large body of literature describing oxidative stress to be evident during and immediately following neonatal anesthesia. Moreover, our review suggests that the short-term pathway has a temporally limited effect on oxidative stress, while the long-term pathway can manifest years later due to the altered development of neurons and neurovascular interactions. [ABSTRACT FROM AUTHOR]

Isoflurane (ISO) is a widely used inhalation anesthetic in experiments with rodents and humans during surgery. Though ISO has not been reported to impart long-lasting side effects, it is unknown if ISO can influence gene regulation in certain tissues, including the heart. Such changes could have important implications for use of this anesthetic in patients susceptible to heart failure/other cardiac abnormalities. To test if ISO could alter gene regulation/expression in heart tissues, and if such changes were reversible, prolonged, or late onset with time, SHR (spontaneously hypertensive) rats were exposed by intratracheal inhalation to a 97.5% air/2.5% ISO mixture on two consecutive days (2 hr/d). Control rats breathed filtered air only. On Days 1, 30, 240, and 360 post-exposure, rat hearts were collected and total RNA was extracted from the left ventricle for global gene expression analysis. The data revealed differentially-expressed genes (DEG) in response to ISO (compared to naïve control) at all post-exposure timepoints. The data showed acute ISO exposures led to DEG associated with wounding, local immune function, inflammation, and circadian rhythm regulation at Days 1 and 30; these effects dissipated by Day 240. There were other significantly-increased DEG induced by ISO at Day 360; these included changes in expression of genes associated with cell signaling, differentiation, and migration, extracellular matrix organization, cell-substrate adhesion, heart development, and blood pressure regulation. Examination of consistent DEG at Days 240 and 360 indicated late onset DEG reflecting potential long-lasting effects from ISO; these included DEG associated with oxidative phosphorylation, ribosome, angiogenesis, mitochondrial translation elongation, and focal adhesion. Together, the data show acute repeated ISO exposures could impart variable effects on gene expression/regulation in the heart. While some alterations self-resolved, others appeared to be long-lasting or late onset. Whether such changes occur in all rat models or in humans remains to be investigated. [ABSTRACT FROM AUTHOR]

Background: Current intensive care unit (ICU) sedation guidelines recommend strategies using non-benzodiazepine sedatives. This survey was undertaken to explore inhaled ICU sedation practice in France. Methods: In this national survey, medical directors of French adult ICUs were contacted by phone or email between July and August 2019. ICU medical directors were questioned about the characteristics of their department, their knowledge on inhaled sedation, and practical aspects of inhaled sedation use in their department. Results: Among the 374 ICUs contacted, 187 provided responses (50%). Most ICU directors (73%) knew about the use of inhaled ICU sedation and 21% used inhaled sedation in their unit, mostly with the Anaesthetic Conserving Device (AnaConDa, Sedana Medical). Most respondents had used volatile agents for sedation for <5 years (63%) and in <20 patients per year (75%), with their main indications being: failure of intravenous sedation, severe asthma or bronchial obstruction, and acute respiratory distress syndrome. Sevoflurane and isoflurane were mainly used (88% and 20%, respectively). The main reasons for not using inhaled ICU sedation were: "device not available" (40%), "lack of medical interest" (37%), "lack of familiarity or knowledge about the technique" (35%) and "elevated cost" (21%). Most respondents (80%) were overall satisfied with the use of inhaled sedation. Almost 75% stated that inhaled sedation was a seducing alternative to intravenous sedation. Conclusion: This survey highlights the widespread knowledge about inhaled ICU sedation in France but shows its limited use to date. Differences in education and knowledge, as well as the recent and relatively scarce literature on the use of volatile agents in the ICU, might explain the diverse practices that were observed. The low rate of mild adverse effects, as perceived by respondents, and the users' satisfaction, are promising for this potentially important tool for ICU sedation. [ABSTRACT FROM AUTHOR]

Background: Adequate sedation is important for the treatment of ICU patients. AnaConDa (Anesthetic-Conserving-Device; ACD; Sedana Medical, Sweden), connected between ventilator and the patient, retains isoflurane during expiration, and releases it back during inspiration. The reflection efficiency (RefEff) corresponds to the percentage of expired anesthetic molecules that are re-inspired. We compared RefEff of AnaConDa-S (ACD-50) and AnaConDa-100 (ACD-100) under laboratory (DRY) and simulated clinical conditions (CLIN) using a test lung. Methods: Measurements were made under DRY and CLIN, with different tidal volumes (TV: 300 mL & 500 mL) and infusion rates (0.5–10 mL·h−1). RefEff was calculated from the isoflurane concentration in the test-lung (CISO) and plotted against the anesthetic vapor volume exhaled in one breath (V-exh = CISO·TV). Results: DRY: RefEff of both devices was ≈90% over a wide range of V-exh, but decreased when V-exh exceeded 5–7 mL (ACD-50) or 10–15 mL (ACD-100). CLIN: RefEff of ACD-50 was 70–80% (ACD-100: 80–90%), decreasing gradually with increasing V-exh. For 1 Vol.% isoflurane at TV500, the infusion rate with ACD-50 was twofold higher compared to ACD-100 (4 versus 2 mL·h−1). Conclusion: Under DRY and concentrations <1.5 Vol.%, RefEff of both devices is around 90%. Under CLIN, ACD-100 performs better with RefEff between 80% and 90% (ACD-50:70–80%), decreasing with increased vapor volume exhaled in one breath. [ABSTRACT FROM AUTHOR]

In recent years, inhaled sedation has been increasingly used in the intensive care unit (ICU). The aim of this prospective, controlled trial was to compare washout and awakening times after long term sedation with desflurane and isoflurane both administered with the Mirus™ system (TIM GmbH, Koblenz, Germany). Twenty-one consecutive critically ill patients were alternately allocated to the two study groups, obtaining inhaled sedation with either desflurane or isoflurane. After 24 h study sedation, anesthetic washout curves were recorded, and a standardized wake-up test was performed. The primary outcome measure was the time required to decrease the endtidal concentration to 50% (T50%). Secondary outcome measures were T80% and awakening times (all extremities moved, RASS −2). Decrement times (min) (desflurane versus isoflurane, median (1st quartile—3rd quartile)) (T50%: 0.3 (0.3–0.4) vs. 1.3 (0.4–2.3), log-rank test P = 0.002; P80%: 2.5 (2–5.9) vs. 12.1 (5.1–20.2), P = 0.022) and awakening times (to RASS −2: 7.5 (5.5–8.8) vs. 41.0 (24.5–43.0), P = 0.007; all extremities moved: 5.0 (4.0–8.5) vs. 13.0 (8.0–41.25), P = 0.037) were significantly shorter after desflurane compared to isoflurane. The use of desflurane with the Mirus™ system significantly shortens the washout times and leads to faster awakening after sedation of critically ill patients. [ABSTRACT FROM AUTHOR]

Background: The MIRUS™ (TIM, Koblenz, Germany) is an electronical gas delivery system, which offers an automated MAC (minimal alveolar concentration)-driven application of isoflurane, sevoflurane, or desflurane, and can be used for sedation in the intensive care unit. We investigated its consumption of volatile anesthetics at 0.5 MAC (primary endpoint) and the corresponding costs. Secondary endpoints were the technical feasibility to reach and control the MAC automatically, the depth of sedation at 0.5 MAC, and awakening times. Mechanically ventilated and sedated patients after major surgery were enrolled. Upon arrival in the intensive care unit, patients obtained intravenous propofol sedation for at least 1 h to collect ventilation and blood gas parameters, before they were switched to inhalational sedation using MIRUS™ with isoflurane, sevoflurane, or desflurane. After a minimum of 2 h, inhalational sedation was stopped, and awakening times were recorded. A multivariate electroencephalogram and the Richmond Agitation Sedation Scale (RASS) were used to assess the depth of sedation. Vital signs, ventilation parameters, gas consumption, MAC, and expiratory gas concentrations were continuously recorded. Results: Thirty patients obtained inhalational sedation for 18:08 [14:46–21:34] [median 1st–3rd quartiles] hours. The MAC was 0.58 [0.50–0.64], resulting in a Narcotrend Index of 37.1 [30.9–42.4] and a RASS of − 3.0 [− 4.0 to (− 3.0)]. The median gas consumption was significantly lowest for isoflurane ([ml h−1]: isoflurane: 3.97 [3.61–5.70]; sevoflurane: 8.91 [6.32–13.76]; and desflurane: 25.88 [20.38–30.82]; p < 0.001). This corresponds to average costs of 0.39 € h−1 for isoflurane, 2.14 € h−1 for sevoflurane, and 7.54 € h−1 for desflurane. Awakening times (eye opening [min]: isoflurane: 9:48 [4:15–20:18]; sevoflurane: 3:45 [0:30–6:30]; desflurane: 2:00 [1:00–6:30]; p = 0.043) and time to extubation ([min]: isoflurane: 10:10 [8:00–20:30]; sevoflurane: 7:30 [4:37–14:22]; desflurane: 3:00 [3:00–6:00]; p = 0.007) were significantly shortest for desflurane. Conclusions: A target-controlled, MAC-driven automated application of volatile anesthetics is technically feasible and enables an adequate depth of sedation. Gas consumption was highest for desflurane, which is also the most expensive volatile anesthetic. Although awakening times were shortest, the actual time saving of a few minutes might be negligible for most patients in the intensive care unit. Thus, using desflurane seems not rational from an economic perspective. Trial registration Clinical Trials Registry (ref.: NCT03860129). Registered 24 September 2018—Retrospectively registered. [ABSTRACT FROM AUTHOR]