Minimal alveolar concentration for deep sedation (MAC-DS) in intensive care unit patients sedated with sevoflurane: A physiological study

Blanchard, Florian; Parratte, Sébastien; James, Arthur; Verdonk, Franck; Godet, Thomas; Bazin, Jean-Étienne; Pereira, Bruno; Lambert, Céline; Constantin, Jean-Michel

doi:10.1016/j.accpm.2020.04.002

Cited by 11 publications

(5 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Regarding the ICU, most authors chose to deliver variable MAC values around 0.5, above the MAC awake threshold [5][6][7][8]. Nonetheless, we found no study related to our primary hypothesis: despite stable ageadjusted MAC, the sedation depth deepens over time.…”

Section: Introductionmentioning

confidence: 67%

Negative drift of sedation depth in critically ill patients receiving constant minimum alveolar concentration of isoflurane, sevoflurane, or desflurane: a randomized controlled trial

et al. 2021

View full text Add to dashboard Cite

Background Intensive care unit (ICU) physicians have extended the minimum alveolar concentration (MAC) to deliver and monitor long-term volatile sedation in critically ill patients. There is limited evidence of MAC’s reliability in controlling sedation depth in this setting. We hypothesized that sedation depth, measured by the electroencephalography (EEG)-derived Narcotrend-Index (burst-suppression N_Index 0—awake N_Index 100), might drift downward over time despite constant MAC values. Methods This prospective single-centre randomized clinical study was conducted at a University Hospital Surgical Intensive Care Unit and included consecutive, postoperative ICU patients fulfilling the inclusion criteria. Patients were randomly assigned to receive uninterrupted inhalational sedation with isoflurane, sevoflurane, or desflurane. The end-expiratory concentration of the anaesthetics and the EEG-derived index were measured continuously in time-stamped pairs. Sedation depth was also monitored using Richmond-Agitation-Sedation-Scale (RASS). The paired t-test and linear models (bootstrapped or multilevel) have been employed to analyze MAC, N_Index and RASS across the three groups. Results Thirty patients were recruited (female/male: 10/20, age 64 ± 11, Simplified Acute Physiology Score II 30 ± 10). In the first 24 h, 21.208 pairs of data points (N_Index and MAC) were recorded. The median MAC of 0.58 ± 0.06 remained stable over the sedation time in all three groups. The t-test indicated in the isoflurane and sevoflurane groups a significant drop in RASS and EEG-derived N_Index in the first versus last two sedation hours. We applied a multilevel linear model on the entire longitudinal data, nested per patient, which produced the formula N_Index = 43 − 0.7·h (R2 = 0.76), showing a strong negative correlation between sedation’s duration and the N_Index. Bootstrapped linear models applied for each sedation group produced: N_Index of 43–0.9, 45–0.8, and 43–0.4·h for isoflurane, sevoflurane, and desflurane, respectively. The regression coefficient for desflurane was almost half of those for isoflurane and sevoflurane, indicating a less pronounced time-effect in this group. Conclusions Maintaining constant MAC does not guarantee stable sedation depth. Thus, the patients necessitate frequent clinical assessments or, when unfeasible, continuous EEG monitoring. The differences across different volatile anaesthetics regarding their time-dependent negative drift requires further exploration. Trial registration: NCT03860129.

show abstract

Section: Introductionmentioning

confidence: 67%

Negative drift of sedation depth in critically ill patients receiving constant minimum alveolar concentration of isoflurane, sevoflurane, or desflurane: a randomized controlled trial

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Finally, although bronchodilation has been reported with higher but also lower dose of sevoflurane, the dose/bronchodilation effect is controversial [ 8 , 10 , 37 ]. We therefore opted for a pragmatic approach that balances the need for deep sedation typically achieved with an expiratory fraction from 0.8 to 1% in the critically ill patients [ 38 ], the potential for bronchodilation and the high risk of volatile sedation-induced hypotension in this critically ill population.…”

Section: Discussionmentioning

confidence: 99%

Early and late effects of volatile sedation with sevoflurane on respiratory mechanics of critically ill COPD patients

Jung,

Fosset,

Amalric

et al. 2024

Ann. Intensive Care

View full text Add to dashboard Cite

Background The objective was to compare sevoflurane, a volatile sedation agent with potential bronchodilatory properties, with propofol on respiratory mechanics in critically ill patients with COPD exacerbation. Methods Prospective study in an ICU enrolling critically ill intubated patients with severe COPD exacerbation and comparing propofol and sevoflurane after 1:1 randomisation. Respiratory system mechanics (airway resistance, PEEPi, trapped volume, ventilatory ratio and respiratory system compliance), gas exchange, vitals, safety and outcome were measured at inclusion and then until H48. Total airway resistance change from baseline to H48 in both sevoflurane and propofol groups was the main endpoint. Results Sixteen patients were enrolled and were sedated for 126 h(61–228) in the propofol group and 207 h(171–216) in the sevoflurane group. At baseline, airway resistance was 21.6cmH2O/l/s(19.8–21.6) in the propofol group and 20.4cmH2O/l/s(18.6–26.4) in the sevoflurane group, (p = 0.73); trapped volume was 260 ml(176–290) in the propofol group and 73 ml(35–126) in the sevoflurane group, p = 0.02. Intrinsic PEEP was 1.5cmH2O(1–3) in both groups after external PEEP optimization. There was neither early (H4) or late (H48) significant difference in airway resistance and respiratory mechanics parameters between the two groups. Conclusions In critically ill patients intubated with COPD exacerbation, there was no significant difference in respiratory mechanics between sevoflurane and propofol from inclusion to H4 and H48.

show abstract

“…As intravenous sedation has to be titrated by ICU teams, inhaled sedation should be managed by an “inhaled titration” of volatile anesthetics agents using scales such as the RASS. All the more, the end-tidal gas concentration monitoring and RASS are correlated in ICU patients [ 39 ]. No data are available to date on the safety and efficacy to manage inhaled sedation only using clinical sedation scores.…”

Section: Discussionmentioning

confidence: 99%

Use of volatile anesthetics for sedation in the ICU during the COVID-19 pandemic: A national survey in France (VOL’ICU 2 study)

et al. 2022

View full text Add to dashboard Cite

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.

show abstract

Minimal alveolar concentration for deep sedation (MAC-DS) in intensive care unit patients sedated with sevoflurane: A physiological study

Cited by 11 publications

References 32 publications

Negative drift of sedation depth in critically ill patients receiving constant minimum alveolar concentration of isoflurane, sevoflurane, or desflurane: a randomized controlled trial

Negative drift of sedation depth in critically ill patients receiving constant minimum alveolar concentration of isoflurane, sevoflurane, or desflurane: a randomized controlled trial

Early and late effects of volatile sedation with sevoflurane on respiratory mechanics of critically ill COPD patients

Use of volatile anesthetics for sedation in the ICU during the COVID-19 pandemic: A national survey in France (VOL’ICU 2 study)

Contact Info

Product

Resources

About