Use of volatile agents for sedation in the intensive care unit: A national survey in France

Guidelines for inhaled sedation in the ICU

INTRODUCTION AND OBJECTIVES

Sedation is used in intensive care units (ICU) to improve comfort and tolerance during mechanical ventilation, invasive interventions, and nursing care. In recent years, the use of inhalation anaesthetics for this purpose has increased. Our objective was to obtain and summarise the best evidence on inhaled sedation in adult patients in the ICU, and use this to help physicians choose the most appropriate approach in terms of the impact of sedation on clinical outcomes and the risk-benefit of the chosen strategy.

METHODOLOGY

Given the overall lack of literature and scientific evidence on various aspects of inhaled sedation in the ICU, we decided to use a Delphi method to achieve consensus among a group of 17 expert panellists. The processes was conducted over a 12-month period between 2022 and 2023, and followed the recommendations of the CREDES guidelines.

RESULTS

The results of the Delphi survey form the basis of these 39 recommendations - 23 with a strong consensus and 15 with a weak consensus.

CONCLUSION

The use of inhaled sedation in the ICU is a reliable and appropriate option in a wide variety of clinical scenarios. However, there are numerous aspects of the technique that require further study.

Inhaled Volatiles for Status Asthmaticus, Epilepsy, and Difficult Sedation in Adult ICU and PICU: A Systematic Review

OBJECTIVES

Inhaled volatile anesthetics support management of status asthmaticus (SA), status epilepticus (SE), and difficult sedation (DS). This study aimed to evaluate the effectiveness, safety, and feasibility of using inhaled anesthetics for SA, SE, and DS in adult ICU and PICU patients.

DATA SOURCES

MEDLINE, Cochrane Central Register of Controlled Trials, and Embase.

STUDY SELECTION

Primary literature search that reported the use of inhaled anesthetics in ventilated patients with SA, SE, and DS from 1970 to 2021.

DATA EXTRACTION

Study data points were extracted by two authors independently. Quality assessment was performed using the Joanna Briggs Institute appraisal tool for case studies/series, Newcastle criteria for cohort/case-control studies, and risk-of-bias framework for clinical trials.

DATA SYNTHESIS

Primary outcome was volatile efficacy in improving predefined clinical or physiologic endpoints. Secondary outcomes were adverse events and delivery logistics. From 4281 screened studies, the number of included studies/patients across diagnoses and patient groups were: SA (adult: 38/121, pediatric: 28/142), SE (adult: 18/37, pediatric: 5/10), and DS (adult: 21/355, pediatric: 10/90). Quality of evidence was low, consisting mainly of case reports and series. Clinical and physiologic improvement was seen within 1-2 hours of initiating volatiles, with variable efficacy across diagnoses and patient groups: SA (adult: 89-95%, pediatric: 80-97%), SE (adults: 54-100%, pediatric: 60-100%), and DS (adults: 60-90%, pediatric: 62-90%). Most common adverse events were cardiovascular, that is, hypotension and arrhythmias. Inhaled sedatives were commonly delivered using anesthesia machines for SA/SE and miniature vaporizers for DS. Few (10%) of studies reported required non-ICU personnel, and only 16% had ICU volatile delivery protocol.

CONCLUSIONS

Volatile anesthetics may provide effective treatment in patients with SA, SE, and DS scenarios but the quality of evidence is low. Higher-quality powered prospective studies of the efficacy and safety of using volatile anesthetics to manage SA, SE, and DS patients are required. Education regarding inhaled anesthetics and the protocolization of their use is needed.

Usage of Inhalative Sedative for Sedation and Treatment of Patient with Severe Brain Injury in Germany, a Nationwide Survey

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.

Renal safety of critical care sedation with sevoflurane: a systematic review and meta-analysis

Volatile anesthetic agents are increasingly widely used for critical care sedation. There are concerns that sevoflurane presents a risk of renal injury when used in this role. RCTs comparing the use of critical care sevoflurane sedation with any control in humans were systematically identified using MEDLINE, Cochrane CENTRAL, web of Science, and CINAHL (until May 2022), if they presented comparative data on renal function or serum inorganic fluoride levels. Pooled SMDs (95% CI) were calculated where possible after assessment of quality with GRADE and risk of bias with ROB-2. Eight studies analyzing 793 patients were included. The median duration of use of critical care sevoflurane sedation was 4.8 [IQR 3.5-9.2] hours; however, most trials also included a period of prior intraoperative use. No significant difference was found in serum creatinine at 1 day (SMD 0.05, 95% CI - 0.12 to 0.21), 48 h (SMD = - 0.04; 95% Cl - 0.25 to 0.17), 72 h (SMD = - 0.15; 95% CI - 0.45 to 0.15), and at discharge (SMD = - 0.1; 95% CI - 0.3 to 0.13) between the sevoflurane group and the control groups. Creatinine clearance was measured in two studies at 48 h with no significant difference (SMD = - 0.13; 95% Cl - 0.38 to 0.11). Levels of serum inorganic fluoride were significantly elevated in patients where sevoflurane was used. Sevoflurane was not associated with renal failure when used for critical care sedation of fewer than 72-h duration, despite the elevation of serum fluoride. Longer-term studies are currently inadequate, including in patients with compromised renal function, to further evaluate the role of sevoflurane in this setting.Trial registration PROSPERO (CRD42022333099).

The advantages of inhalational sedation using an anesthetic-conserving device versus intravenous sedatives in an intensive care unit setting: A systematic review

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.

Comparison between sevoflurane and propofol on immunomodulation in an in vitro model of sepsis

Introduction

Patients with sepsis often require sedation and/or anesthesia. Although the immunomodulatory effects of anesthetics have been increasingly recognized, the molecular mechanisms require better elucidation. We compared the effects of sevoflurane with propofol on the expression of pro- and anti-inflammatory biomarkers released by monocytes/macrophages and blood/bronchoalveolar lavage fluid (BALF) neutrophils, the phagocytic capacity of monocytes/ macrophages, and neutrophil migration, as well as mediators associated with alveolar epithelial and endothelial cells obtained from rats with sepsis.

Methods

Polymicrobial sepsis was induced by cecal ligation and puncture in nine male Wistar rats. After 48 h, animals were euthanized and their monocytes/alveolar macrophages, blood and BALF neutrophils, as well as alveolar epithelial and endothelial cells were extracted, and then exposed to (1) sevoflurane (1 minimal alveolar concentration), (2) propofol (50 μM), or (3) saline, control (CTRL) for 1 h.

Results

Sevoflurane reduced interleukin (IL)-6 mRNA expression in monocytes and alveolar macrophages (p = 0.007, p = 0.029), whereas propofol decreased IL-6 mRNA only in alveolar macrophages (p = 0.027) compared with CTRL. Sevoflurane increased IL-10 expression (p = 0.0002) in monocytes compared with propofol and increased IL-10 mRNA and transforming growth factor (TGF)-β mRNA (p = 0.037, p = 0.045) compared with CTRL. Both sevoflurane and propofol did not affect mRNA expression of IL-10 and TGF-β in alveolar macrophages. The phagocytic capacity of monocytes (p = 0.0006) and alveolar macrophages (p = 0.0004) was higher with sevoflurane compared with propofol. Sevoflurane, compared with CTRL, reduced IL-1β mRNA (p = 0.003, p = 0.009) and C-X-C chemokine receptor 2 mRNA (CXCR2, p = 0.032 and p = 0.042) in blood and BALF neutrophils, and increased CXCR4 mRNA only in BALF neutrophils (p = 0.004). Sevoflurane increased blood neutrophil migration (p = 0.015) compared with propofol. Both sevoflurane and propofol increased zonula occludens-1 mRNA (p = 0.046, p = 0.003) in alveolar epithelial cells and reduced Toll-like receptor 4 mRNA (p = 0.043, p = 0.006) in alveolar endothelial cells compared with CTRL. Only propofol reduced surfactant protein B mRNA (p = 0.028) in alveolar epithelial cells.

Discussion

Sevoflurane, compared with propofol, increased anti-inflammatory biomarkers in monocytes, but not in alveolar macrophages, enhanced monocyte/alveolar macrophage phagocytic capacity and increased neutrophil migration in in vitro experimental sepsis. Both propofol and sevoflurane protected lung epithelial and endothelial cells.

Halogenated anesthetics vs intravenous hypnotics for short and long term sedation in the intensive care unit: A meta-analysis

OBJECTIVE

To comprehensively assess peer-reviewed studies using volatile (VA) or intravenous (i/v) anesthetics for sedation in intensive care units (ICUs), with the hypothesis that the type of sedation may have an impact on survival and other clinically relevant outcomes.

DESIGN

Systematic review and meta-analysis of randomized and non-randomized trials.

SETTING

ICUs.

PARTICIPANTS

Critically ill and postoperative patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Studies comparing VA versus i/v anesthetics used in the ICU settings were independently systematically searched. Finally, 15 studies (1520 patients of predominantly surgical profile needed VA sedation for less than 96h) were included. VA had no impact on all-cause mortality (very low quality of evidence, Odds Ratio=0.82 [0.60-1.12], p=0.20). However, VA were associated with a reduction in duration of mechanical ventilation (p=0.03) and increase in ventilator-free days (p<0.001). VA also reduced postoperative levels of cardiac troponin (24h), time to extubation (p<0.001) and awakening (p=0.04).

CONCLUSIONS

In this meta-analysis, volatile sedation vs propofol caused the increase in ventilator-free days, the reduction in the duration of mechanical ventilation, time to extubation and the troponin release in medical or surgical ICU patients, while in surgical ICU patients the time to awakening was shortened.

Inhaled Sedation with Volatile Anesthetics for Mechanically Ventilated Patients in Intensive Care Units: A Narrative Review

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.

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

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.

Sedation, sleep-promotion, and non-verbal and verbal communication techniques in critically ill intubated or tracheostomized patients: results of a survey

BACKGROUND

The aim of this survey was to describe, on a patient basis, the current practice of sedation, pharmacologic and non-pharmacologic measures to promote sleep and facilitation of communication in critically ill patients oro-tracheally intubated or tracheostomized.

METHODS

Cross-sectional online-survey evaluating sedation, sleep management and communication in oro-tracheally intubated (IP) or tracheostomized (TP) patients in intensive care units on a single point.

RESULTS

Eighty-one intensive care units including 447 patients (IP: n = 320, TP: n = 127) participated. A score of ≤ -2 on the Richmond Agitation Sedation Scale (RASS) was prevalent in 58.2% (IP 70.7% vs. TP 26.8%). RASS -1/0 was present in 32.2% (IP 25.9% vs. TP 55.1%) of subjects. Propofol and alpha-2-agonist were the predominant sedatives used while benzodiazepines were applied in only 12.1% of patients. For sleep management, ear plugs and sleeping masks were rarely used (< 7%). In half of the participating intensive care units a technique for phonation was used in the tracheostomized patients.

CONCLUSIONS

The overall rate of moderate and deep sedation appears high, particularly in oro-tracheally intubated patients. There is no uniform sleep management and ear plugs and sleeping masks are only rarely applied. The application of phonation techniques in tracheostomized patients during assisted breathing is low. More efforts should be directed towards improved guideline implementation. The enhancement of sleep promotion and communication techniques in non-verbal critically ill patients may be a focus of future guideline development.

Safety and Feasibility of AnaConDa™ to Deliver Inhaled Isoflurane for Sedation in Patients Undergoing Elective Postoperative Mechanical Ventilation: A Prospective, Open-label, Interventional Trial (INSTINCT I Study)

Aim

Sedation is essential during invasive mechanical ventilation, and conventionally intravenous analgesic and sedative drugs are used. Sedation with inhaled anesthetics using anesthesia conserving device (ACD) is an alternative. There is no data on the safety and ease of use of AnaConDa™ from India.

Materials and methods

After IEC approval and informed consent, we used AnaConDa™-S for Isoflurane sedation in 50 hemodynamically stable (need for <0.5 µg/kg/min of Noradrenaline infusion), ASA I and II patients aged 18-80 years, undergoing elective mechanical ventilation for up to 24 hours after elective oncosurgeries. Patients with mental obtundation (GCS <14), or if pregnant, were excluded. The primary outcome was time spent between RASS scores of -3 and -4, while secondary outcomes were incidence of delirium, technical problems with AnaConDa™, and adverse systemic effects of isoflurane. Bolus doses of isoflurane 0.2-0.5 mL were given if the Richmond agitation sedation scale (RASS) score was not achieved.

Results

Fifty patients received isoflurane infusion for a median of 720 (IQR 630-900) minutes, and all remained in the target sedation range. Median time to awakening [19 (IQR, 5-85) minutes], to follow simple verbal commands [20 (IQR 5-180) minutes], and extubation after stopping the infusion of isoflurane was quick [100 (10-470) minutes]. All patients remained hemodynamically stable. None of the patients had delirium.

Conclusion

Target sedation levels were achieved with initial boluses of isoflurane using AnaConDa™-S. Isoflurane sedation delivery using AnaConDa™-S is safe and feasible.

How to cite this article

Kulkarni AP, Bhosale SJ, Kalvit KR, Sahu TK, Mohanty R, Dhas MM, et al. Safety and Feasibility of AnaConDa™ to Deliver Inhaled Isoflurane for Sedation in Patients Undergoing Elective Postoperative Mechanical Ventilation: A Prospective, Open-label, Interventional Trial (INSTINCT I Study). Indian J Crit Care Med 2022;26(8):906-912.

Inhaled sedation in the intensive care unit

Inhaled sedation with halogenated agents, such as isoflurane or sevoflurane, is now feasible in intensive care unit (ICU) patients through dedicated vaporisers and scavenging systems. Such a sedation strategy requires specific equipment and adequate training of ICU teams. Isoflurane and sevoflurane have ideal pharmacological properties that allow efficient, well-tolerated, and titratable light-to-deep sedation. In addition to their function as sedative agents, these molecules may have clinical benefits that could be especially relevant to ICU patients. Our goal was to summarise the pharmacological basis and practical aspects of inhaled ICU sedation, review the available evidence supporting inhaled sedation as a viable alternative to intravenous sedation, and discuss the remaining areas of uncertainty and future perspectives of development.

Design and Rationale of the Sevoflurane for Sedation in Acute Respiratory Distress Syndrome (SESAR) Randomized Controlled Trial

Preclinical studies have shown that volatile anesthetics may have beneficial effects on injured lungs, and pilot clinical data support improved arterial oxygenation, attenuated inflammation, and decreased lung epithelial injury in patients with acute respiratory distress syndrome (ARDS) receiving inhaled sevoflurane compared to intravenous midazolam. Whether sevoflurane is effective in improving clinical outcomes among patients with ARDS is unknown, and the benefits and risks of inhaled sedation in ARDS require further evaluation. Here, we describe the SESAR (Sevoflurane for Sedation in ARDS) trial designed to address this question. SESAR is a two-arm, investigator-initiated, multicenter, prospective, randomized, stratified, parallel-group clinical trial with blinded outcome assessment designed to test the efficacy of sedation with sevoflurane compared to intravenous propofol in patients with moderate to severe ARDS. The primary outcome is the number of days alive and off the ventilator at 28 days, considering death as a competing event, and the key secondary outcome is 90 day survival. The planned enrollment is 700 adult participants at 37 French academic and non-academic centers. Safety and long-term outcomes will be evaluated, and biomarker measurements will help better understand mechanisms of action. The trial is funded by the French Ministry of Health, the European Society of Anaesthesiology, and Sedana Medical.

Avoiding kidney damage in ICU sedation with sevoflurane: use isoflurane instead

Intensive care unit (ICU) sedation with sevoflurane is associated with nephrogenic diabetes insipidus. Given that isoflurane is now licenced (in Europe) for ICU sedation and has Investigational New Drug status in the USA, evidence indicates that clinicians should stop using sevoflurane in this indication except in the context of clinical trials.