Safety and Efficacy of Volatile Anesthetic Agents Compared With Standard Intravenous Midazolam/Propofol Sedation in Ventilated Critical Care Patients

Medication burden in patients with dialysis-dependent CKD: a systematic review

This systematic review aimed to statistically profile the medication burden and associated influencing factors, and outcomes in patients with dialysis-dependent chronic kidney disease (DD-CKD). Studies of medication burden in patients with DD-CKD in the last 10 years from 1 January 2013 to 31 March 2024 were searched from PubMed, Embase, and Cochrane databases. Newcastle-Ottawa Scale (NOS) or Agency for Healthcare Research and Quality (AHRQ) methodology checklist was used to evaluate quality and bias. Data extraction and combining from multiple groups of number (n), mean, and standard deviation (SD) were performed using R programming language (version4.3.1; R Core Team, Vienna, Austria). A total of 10 studies were included, and the results showed a higher drug burden in patients with DD-CKD. The combined pill burden was 14.57 ± 7.56 per day in hemodialysis (HD) patients and 14.63 ± 6.32 in peritoneal dialysis (PD) patients. The combined number of medications was 9.74 ± 3.37 in HD and 8 ± 3 in PD. Four studies described the various drug classes and their proportions, in general, antihypertensives and phosphate binders were the most commonly used drugs. Five studies mentioned factors associated with medication burden. A total of five studies mentioned medication burden-related outcomes, with one study finding that medication-related burden was associated with increased treatment burden, three studies finding that poor medication adherence was associated with medication burden, and another study finding that medication complexity was not associated with self-reported medication adherence. Limitations: meta-analysis was not possible due to the heterogeneity of studies.

Practical approach to inhaled sedation in the critically ill patient. Sedation, analgesia and Delirium Working Group (GTSAD) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC)

The use of sedatives in Intensive Care Units (ICU) is essential for relieving anxiety and stress in mechanically ventilated patients, and it is related to clinical outcomes, duration of mechanical ventilation, and length of stay in the ICU. Inhaled sedatives offer benefits such as faster awakening and extubation, decreased total opioid and neuromuscular blocking agents (NMB) doses, as well as bronchodilator, anticonvulsant, and cardiopulmonary and neurological protective effects. Inhaled sedation is administered using a specific vaporizer. Isoflurane is the recommended agent due to its efficacy and safety profile. Inhaled sedation is recommended for moderate and deep sedation, prolonged sedation, difficult sedation, patients with acute respiratory distress syndrome (ARDS), status asthmaticus, and super-refractory status epilepticus. By offering these significant advantages, the use of inhaled sedatives allows for a personalized and controlled approach to optimize sedation in the ICU.

Sedaconda ACD-S for Sedation with Volatile Anaesthetics in Intensive Care: A NICE Medical Technologies Guidance

Intensive care unit (ICU) patients receive highly complex care and often require sedation as part of their management. ICU sedation has traditionally been delivered using intravenous (IV) agents due to the impractical use of anaesthetic machines in this setting, which are used to deliver volatile sedation. Sedaconda anaesthetic conserving device (ACD)-S (previously known as AnaConDa-S) is a device which allows for the delivery of volatile sedation via the majority of mechanical ventilators by being inserted in the breathing circuit where the heat and moisture exchanger is normally placed. The National Institute of Health and Care Excellence (NICE), as part of the Medical Technologies Evaluation Programme, considered the potential benefits of using Sedaconda ACD-S compared to standard IV sedation in ICU patients. Here we describe the evidence evaluation undertaken by NICE on this technology, supported by CEDAR. CEDAR considered the evidence present in 21 publications that compared the clinical outcomes of patients receiving Sedaconda ACD-S-delivered sedation and IV sedation, and critiqued the economic model provided by the manufacturer. Clinical expert input during the evaluation process was used extensively to ensure that the relevant clinical evidence was captured and that the economic model was suitable for the UK setting. Due to the uncertainty of the evidence, sensitivity analysis was carried out on the key economic inputs to ensure the reliability of the results. Economic modelling has shown that Sedaconda ACD-S-delivered isoflurane sedation is cost saving on a 30-day horizon compared to IV sedation by £3833.76 per adult patient and by £2837.41 per paediatric patient. Clinical evidence indicated that Sedaconda ACD-S-delivered isoflurane sedation is associated with faster patient wake-up times than standard of care. Consequently, NICE recommended Sedaconda ACD-S as an option for delivering sedation in the ICU setting, but noted that further research should inform whether Sedaconda ACD-S-delivered sedation is of benefit to any particular subgroup of patients.

Volatile Anesthetic Sedation for Critically Ill Patients

Volatile anesthetics have multiple properties that make them useful for sedation in the intensive care unit. The team-based approach to volatile anesthetic sedation leverages these properties to provide a safe and effective alternative to intravenous sedatives.

Sedation modality in acute respiratory distress syndrome: does method of sedation affect length of stay, outcomes, or adverse events? A systematic review

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is a life-threatening, diffuse inflammatory pulmonary condition characterised by the Berlin criteria. Incidence of ARDS is estimated at 2.5-19% globally with high mortality and morbidity. Interest has been increasing in the use of inhaled sedatives because of a more rapid awakening and fewer adverse effects compared with intravenous propofol. The primary aim of this systematic review protocol is to investigate the length of critical care stay between ARDS patients who have been mechanically ventilated with inhaled anaesthetic sedatives (ie, sevoflurane and isoflurane) compared with those patients who are prescribed conventional sedatives (ie, propofol).

METHODS AND ANALYSIS

Cochrane Central Register of Controlled Trials, Ovid (Embase, MEDLINE), PubMed, EBSCO (CINAHL Plus), Google Scholar will be searched and stratified by the reviewers. The literature search will be limited to English articles. Published full text peer-reviewed articles will be included.The International Prospective Register of Systematic Reviews (PROSPERO) Registration number is: CRD42023390988.

ETHICS AND DISSEMINATION

Ethics approval is not required for this systematic review. The results will be presented at local/regional meetings and dissemination will occur through peer-reviewed publication.

Volatile versus propofol sedation after cardiac valve surgery: a single-center prospective randomized controlled trial

BACKGROUND

Optimal intensive care of patients undergoing valve surgery is a complex balancing act between sedation for monitoring and timely postoperative awakening. It remains unclear, if these requirements can be fulfilled by volatile sedations in intensive care medicine in an efficient manner. Therefore, this study aimed to assess the time to extubation and secondary the workload required.

METHODS

We conducted a prospective randomized single-center trial at a tertiary university hospital to evaluate the postoperative management of open valve surgery patients. The study was randomized with regard to the use of volatile sedation compared to propofol sedation. Sedation was discontinued 60 min after admission for critical postoperative monitoring.

RESULTS

We observed a significantly earlier extubation (91 ± 39 min vs. 167 ± 77 min; p < 0.001), eye-opening (86 ± 28 min vs. 151 ± 71 min; p < 0.001) and command compliance (93 ± 38 min vs. 164 ± 75 min; p < 0.001) using volatile sedation, which in turn was associated with a significantly increased workload of a median of 9:56 min (± 4:16 min) set-up time. We did not observe any differences in complications. Cardiopulmonary bypass time did not differ between the groups 101 (IQR 81; 113) versus 112 (IQR 79; 136) minutes p = 0.36.

CONCLUSIONS

Using volatile sedation is associated with few minutes additional workload in assembling and enables a significantly accelerated evaluation of vulnerable patient groups. Volatile sedation has considerable advantages and emerges as a safe sedation technique in our vulnerable study population.

TRIAL REGISTRATION

Clinical trials registration (NCT04958668) was completed on 1 July 2021.

Early sevoflurane sedation in severe COVID-19-related lung injury patients. A pilot randomized controlled trial

BACKGROUND

This study aimed to assess a potential organ protective effect of volatile sedation in a scenario of severe inflammation with an early cytokine storm (in particular IL-6 elevation) in patients suffering from COVID-19-related lung injury with invasive mechanical ventilation and sedation.

METHODS

This is a small-scale pilot multicenter randomized controlled trial from four tertiary hospitals in Switzerland, conducted between April 2020 and May 2021. 60 patients requiring mechanical ventilation due to severe COVID-19-related lung injury were included and randomized to 48-hour sedation with sevoflurane vs. continuous intravenous sedation (= control) within 24 h after intubation. The primary composite outcome was determined as mortality or persistent organ dysfunction (POD), defined as the need for mechanical ventilation, vasopressors, or renal replacement therapy at day 28. Secondary outcomes were the length of ICU and hospital stay, adverse events, routine laboratory parameters (creatinine, urea), and plasma inflammatory mediators.

RESULTS

28 patients were randomized to sevoflurane, 32 to the control arm. The intention-to-treat analysis revealed no difference in the primary endpoint with 11 (39%) sevoflurane and 13 (41%) control patients (p = 0.916) reaching the primary outcome. Five patients died within 28 days in each group (16% vs. 18%, p = 0.817). Of the 28-day survivors, 6 (26%) and 8 (30%) presented with POD (p = 0.781). There was a significant difference regarding the need for vasopressors (1 (4%) patient in the sevoflurane arm, 7 (26%) in the control one (p = 0.028)). Length of ICU stay, hospital stay, and registered adverse events within 28 days were comparable, except for acute kidney injury (AKI), with 11 (39%) sevoflurane vs. 2 (6%) control patients (p = 0.001). The blood levels of IL-6 in the first few days after the onset of the lung injury were less distinctly elevated than expected.

CONCLUSIONS

No evident benefits were observed with short sevoflurane sedation on mortality and POD. Unexpectedly low blood levels of IL-6 might indicate a moderate injury with therefore limited improvement options of sevoflurane. Acute renal issues suggest caution in using sevoflurane for sedation in COVID-19.

TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov (NCT04355962) on 2020/04/21.

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.

Sedation for Patients with Sepsis: Towards a Personalised Approach

This article looks at the challenges of sedoanalgesia for sepsis patients, and argues for a personalised approach. Sedation is a necessary part of treatment for patients in intensive care to reduce stress and anxiety and improve long-term prognoses. Sepsis patients present particular difficulties as they are at increased risk of a wide range of complications, such as multiple organ failure, neurological dysfunction, septic shock, ARDS, abdominal compartment syndrome, vasoplegic syndrome, and myocardial dysfunction. The development of any one of these complications can cause the patient's rapid deterioration, and each has distinct implications in terms of appropriate and safe forms of sedation. In this way, the present article reviews the sedative and analgesic drugs commonly used in the ICU and, placing special emphasis on their strategic administration in sepsis patients, develops a set of proposals for sedoanalgesia aimed at improving outcomes for this group of patients. These proposals represent a move away from simplistic approaches like avoiding benzodiazepines to more "objective-guided sedation" that accounts for a patient's principal pathology, as well as any comorbidities, and takes full advantage of the therapeutic arsenal currently available to achieve personalised, patient-centred treatment goals.

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).

Sevoflurane sedation in COVID-19 acute respiratory distress syndrome: an observational study with a propensity score matching model

Introduction

The management of severe COVID-19-induced acute respiratory distress syndrome (C-ARDS) often involves deep sedation. This study evaluated the efficacy of sevoflurane, a volatile anesthetic, as an alternative to traditional intravenous sedation in this patient population.

Methods

This single-center, retrospective cohort study enrolled 112 patients with C-ARDS requiring invasive mechanical ventilation. A propensity score matching model was utilized to pair 56 patients receiving sevoflurane sedation with 56 patients receiving intravenous sedation. The primary outcome was mortality, with secondary outcomes being changes in oxygenation (PaO2/FiO2 ratio), pulmonary compliance, and levels of D-Dimer, CRP, and creatinine.

Results

The use of sevoflurane was associated with a statistically significant reduction in mortality (OR 0.40, 95% CI 0.18-0.87, beta = -0.9, p = 0.02). In terms of secondary outcomes, an increase in the PaO2/FiO2 ratio and pulmonary static compliance was observed, although the results were not statistically significant. No significant differences were noted in the levels of D-Dimer, CRP, and creatinine between the two groups.

Conclusion

Our findings suggest an association between the use of sevoflurane and improved outcomes in C-ARDS patients requiring invasive mechanical ventilation. However, due to the single-center, retrospective design of the study, caution should be taken in interpreting these results, and further research is needed to corroborate these findings. The study offers promising insights into potential alternative sedation strategies in the management of severe C-ARDS.

Effect of inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults: a systematic review and meta-analysis

BACKGROUND

Sedation of critically ill patients with inhaled anaesthetics may reduce lung inflammation, time to extubation, and ICU length of stay compared with intravenous (i.v.) sedatives. However, the impact of inhaled anaesthetics on cognitive and psychiatric outcomes in this population is unclear. In this systematic review, we aimed to summarise the effect of inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults.

METHODS

We searched MEDLINE, EMBASE, and PsycINFO for case series, retrospective, and prospective studies in critically ill adults sedated with inhaled anaesthetics. Outcomes included delirium, psychomotor and neurological recovery, long-term cognitive dysfunction, ICU memories, anxiety, depression, post-traumatic stress disorder (PTSD), and instruments used for assessment.

RESULTS

Thirteen studies were included in distinct populations of post-cardiac arrest survivors (n=4), postoperative noncardiac patients (n=3), postoperative cardiac patients (n=2), and mixed medical-surgical patients (n=4). Eight studies reported delirium incidence, two neurological recovery, and two ICU memories. One study reported on psychomotor recovery, long-term cognitive dysfunction, anxiety, depression, and PTSD. A meta-analysis of five trials found no difference in delirium incidence between inhaled and i.v. sedatives (relative risk 0.95 [95% confidence interval: 0.59-1.54]). Compared with i.v. sedatives, inhaled anaesthetics were associated with fewer hallucinations and faster psychomotor recovery but no differences in other outcomes. There was heterogeneity in the instruments used and timing of these assessments.

CONCLUSIONS

Based on the limited evidence available, there is no difference in cognitive and psychiatric outcomes between adults exposed to volatile sedation or intravenous sedation in the ICU. Future studies should incorporate outcome assessment with validated tools during and after hospital stay.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021236455.

Balanced volatile sedation with isoflurane in critically ill patients with aneurysmal subarachnoid hemorrhage - a retrospective observational study

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 low-dose 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.

Sedation with Sevoflurane versus Propofol in COVID-19 Patients with Acute Respiratory Distress Syndrome: Results from a Randomized Clinical Trial

BACKGROUND

Acute respiratory distress syndrome (ARDS) related to COVID-19 (coronavirus disease 2019) led to intensive care units (ICUs) collapse. Amalgams of sedative agents (including volatile anesthetics) were used due to the clinical shortage of intravenous drugs (mainly propofol and midazolam).

METHODS

A multicenter, randomized 1:1, controlled clinical trial was designed to compare sedation using propofol and sevoflurane in patients with ARDS associated with COVID-19 infection in terms of oxygenation and mortality.

RESULTS

Data from a total of 17 patients (10 in the propofol arm and 7 in the sevoflurane arm) showed a trend toward PaO₂/FiO₂ improvement and the sevoflurane arm's superiority in decreasing the likelihood of death (no statistical significance was found).

CONCLUSIONS

Intravenous agents are the most-used sedative agents in Spain, even though volatile anesthetics, such as sevoflurane and isoflurane, have shown beneficial effects in many clinical conditions. Growing evidence demonstrates the safety and potential benefits of using volatile anesthetics in critical situations.

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.

Prolonged sedation with sevoflurane in comparison to intravenous sedation in critically ill patients - A randomized controlled trial

BACKGROUND

Volatile anesthetics are used more commonly for sedation in the intensive-care-unit (ICU). However, evidence for long-term use remains low. We therefore conducted a randomized-controlled trial comparing sevoflurane with intravenous sedation with particular focus on efficacy and safety.

METHODS

In this prospective, randomized-controlled phase-IIb monocentric clinical-trial ICU patients requiring at least 48 h of sedation were randomized to receive sevoflurane (S) or propofol/midazolam (P). Sedation quality was monitored using the Richmond-Agitation-Sedation-Scale. Following termination of sedation, the time to spontaneous breathing and extubation, opioid consumption, hemodynamics, ICU and hospital length of stay (LOS) and adverse events were recorded.

RESULTS

79 patients were eligible to randomization. Sedation quality was comparable between sevoflurane (n = 39) and propofol (n = 40). However, the use of sevoflurane lead to a reduction in time to spontaneous breathing (26 min vs. 375 min, P < 0.001). Patients sedated with propofol had lower opioid requirements (remifentanil:400 μg/h vs. 500 μg/h, P = 0.007; sufentanil:40 μg/h vs. 30 μg/h, P = 0.007) while hemodynamics, LOS or the occurrence of adverse events did not differ.

CONCLUSION

ICU patients sedated with sevoflurane >48 h may return to spontaneous breathing faster, while the quality of sedation is comparable to a propofol-based sedation regime. Sevoflurane might be considered to be safe for long-term sedation in this patient population, while being non-inferior compared to propofol.

The impact of the coronavirus pandemic on sedation in critical care: volatile anesthetics in the ICU

PURPOSE OF REVIEW

To reflect on the impact of the coronavirus pandemic on sedation for mechanically ventilated patients.

RECENT FINDINGS

Shortages of intravenous sedatives during coronavirus pandemic renewed interest in using widely available inhaled anaesthetics for sedation of critically ill patients. Universally used for surgical anaesthesia, inhaled anaesthetics may offer therapeutic advantages in patients with acute lung injury with good sedation profiles, rapid clearance and lower lung inflammation in pilot trials. However, enabling ICU sedation with inhaled anaesthetics required technological and human resource innovation during the chaos of the global pandemic. The disruption of standard sedation practices is challenging during normal operations, yet pandemic facilitated innovation in this field by fostering cross-discipline collaboration supported by healthcare professionals, hospitals, research institutes and regulators.

SUMMARY

Although further research is needed to establish the role of inhaled anaesthetics in critical care sedation toolkit, maintaining the spirit of innovation ignited during the recent coronavirus pandemic would require ongoing collaboration and streamlining of processes among healthcare, research and regulatory institutions.

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.

Inhaled Sedation in Patients with COVID-19-Related Acute Respiratory Distress Syndrome: An International Retrospective Study

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.

Sevoflurane Ameliorates Schizophrenia in a Mouse Model and Patients: A Pre-Clinical and Clinical Feasibility Study

BACKGROUND

GABAergic deficits have been considered to be associated with the pathophysiology of schizophrenia, and hence, GABA receptors subtype A (GABA_ARs) modulators, such as commonly used volatile anesthetic sevoflurane, may have therapeutic values for schizophrenia. The present study investigates the therapeutic effectiveness of low-concentration sevoflurane in MK801-induced schizophrenia-like mice and schizophrenia patients.

METHODS

Three weeks after MK801 administration (0.5 mg kg^-1, i.p. twice a day for 5 days), mice were exposed to 1% sevoflurane 1hr/day for 5 days. Behavioral tests, immunohistochemical analysis, western blot assay, and electrophysiology assessments were performed 1-week post-exposure. Ten schizophrenia patients received 1% sevoflurane 5 hrs per day for 6 days and were assessed with the Positive and Negative Syndrome Scale (PANSS) and the 18-item Brief Psychiatric Rating Scale (BPRS-18) at week 1 and week 2.

RESULTS

MK801 induced hypolocomotion and social deficits, downregulated expression of NMDARs subunits and postsynaptic density protein 95 (PSD95), reduced parvalbumin - and GAD67-positive neurons, altered amplitude and frequency of mEPSCs and mIPSCs, and increased the excitation/inhibition ratio. All these changes induced by MK-801 were attenuated by sevoflurane administration. Six and eight patients achieved a response defined as a reduction of at least 30% in the PANSS total score at 1st and 2nd week after treatments. The BPRS-18 total score was found to be significantly decreased by 38% at the 2nd week (p < 0.01).

CONCLUSION

Low-concentration sevoflurane effectively reversed MK801-induced schizophrenialike disease in mice and alleviated schizophrenia patients' symptoms. Our work suggests sevoflurane to be a valuable therapeutic strategy for treating schizophrenia patients.

50% effective concentration of sevoflurane for immobility in cerebral palsy children undergoing botulinum toxin injection

BACKGROUND

This prospective study aimed to determine the optimum end-tidal sevoflurane concentration required for immobility during botulinum toxin injection in spontaneously breathing children with cerebral palsy (CP).

METHODS

Twenty-three children with spastic CP, aged 3 to 12 years, with American Society of Anesthesiologists (ASA) physical status I and II, scheduled to receive botulinum toxin type A injection were enrolled in the study. After induction of deep sedation using pre-filled 8% sevoflurane in oxygen and maintenance of the predetermined end-tidal sevoflurane concentration, the botulinum toxin was injected in spontaneously breathing children. The response to the botulinum toxin injection was classified as "movement" or "no movement" by an independent investigator who was blinded to the predetermined end-tidal sevoflurane concentration and bispectral index (BIS) value. The end-tidal sevoflurane concentration was predetermined, initiating at 2.0% with 0.2% as a step size in the next patient depending on the previous patient's response using the modified Dixon's up-and-down method.

RESULTS

Of 21 children, 12 (57.1%) showed "no movement" in response to the botulinum toxin injection. By Dixon's up-and-down method, the 50% effective end-tidal concentration (EC50) of sevoflurane for successful botulinum toxin injection was 1.76 ± 0.15% (95% CI 1.62-1.90). Based on the dose-response curve using probit analysis, the predicted EC50 and 95% effective end-tidal concentrations (EC95) of sevoflurane without movement were 1.77% (95% CI 1.59-2.35) and 2.09% (95% CI 1.89-5.80), respectively.

CONCLUSION

Botulinum toxin injection can be successfully accomplished at an end-tidal sevoflurane concentration of 1.76 ± 0.15% in 50% of spontaneously breathing children with CP aged 3-12 years.

Volatile Anaesthesia versus Total Intravenous Anaesthesia for Cardiac Surgery—A Narrative Review

Recent research has contested the previously accepted paradigm that volatile anaesthetics improve outcomes in cardiac surgery patients when compared to intravenous anaesthesia. In this review we summarise the mechanisms of myocardial ischaemia/reperfusion injury and cardioprotection in cardiac surgery. In addition, we make a comprehensive analysis of evidence comparing outcomes in patients undergoing cardiac surgery under volatile or intravenous anaesthesia, in terms of mortality and morbidity (cardiac, neurological, renal, pulmonary).

100 Years of Critical Care in the Pages of Anesthesia & Analgesia

The founding of Anesthesia & Analgesia (A&A) in 1922 was roughly contemporaneous with the creation of the first intensive care unit (ICU) in the United States at Johns Hopkins in 1923. Throughout the next 100 years, the pages of A&A have mirrored the development of critical care as its own distinct specialty. Although primarily a journal focused on intraoperative anesthesia, A&A has maintained a small but steady presence in critical care research. This review highlights the history and development of critical care publications in the pages of A&A from early observations on the physiology of critical illness (1922-1949) to the groundbreaking work of Peter Safar and others on cardiopulmonary resuscitation (1950-1970), the growth of modern critical care (1970-2010), and the 2020 to 2022 coronavirus disease 2019 (COVID-19) era.

Inhaled Anesthetics for Sedation in ICU: Widening Horizons!

How to cite this article: Krishna B. Inhaled Anesthetics for Sedation in ICU: Widening Horizons! Indian J Crit Care Med 2022;26(8):889–891.

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.

Inhaled Sedation for Invasively Ventilated COVID-19 Patients: A Systematic Review

Background: Volatile anesthetics were used as sedative agents in COVID-19 (Coronavirus Disease 2019) invasively ventilated patients for their potentially beneficial pharmacological effects and due to the temporary shortages of intravenous agents during the pandemic crisis. Methods: Online databases (PubMed, EMBASE, The Cochrane Central Register of Controlled Trial) and the “clinicaltrials.gov” website were searched for studies reporting the use of isoflurane, sevoflurane or desflurane. Results: We identified three manuscripts describing the beneficial effects of isoflurane on 41 COVID-19 patients with acute respiratory distress syndrome (ARDS) in Germany (n = 2) and in the USA (n = 1), in terms of reduction in the use of opioids and other sedatives. We also found a case report of two patients with transient nephrogenic diabetes insipidus, which started after 6 and 8 days of sevoflurane sedation. We identified two randomized controlled trials (RCTs; 92 patients overall), two observational studies (238 patients) on the use of volatile anesthetics in COVID-19 patients that were completed but not yet published, and one RCT interrupted for a low recruitment ratio (19 patients) and thus not published. We also identified five ongoing RCTs on the use of inhaled sedation in ARDS, which are also likely to be recruiting COVID-19 patients and which have currently enrolled a total of >1643 patients. Conclusion: Isoflurane was the most frequently used volatile agent in COVID-19 patients and allowed a reduction in the use of other sedative and analgesic drugs. Randomized evidence is building up and will be useful to confirm or challenge these findings.

Sevoflurane Dampens Acute Pulmonary Inflammation via the Adenosine Receptor A2B and Heme Oxygenase-1

Acute respiratory distress syndrome is a life-threatening disease associated with high mortality. The adenosine receptor A2B (Adora2b) provides anti-inflammatory effects, which are also associated with the intracellular enzyme heme oxygenase-1 (HO-1). Our study determined the mechanism of sevoflurane’s protective properties and investigated the link between sevoflurane and the impact of a functional Adora2b via HO-1 modulation during lipopolysaccharide (LPS)-induced lung injury. We examined the LPS-induced infiltration of polymorphonuclear neutrophils (PMNs) into the lung tissue and protein extravasation in wild-type and Adora2b−/− animals. We generated chimeric animals, to identify the impact of sevoflurane on Adora2b of hematopoietic and non-hematopoietic cells. Sevoflurane decreased the LPS-induced PMN-infiltration and diminished the edema formation in wild-type mice. Reduced PMN counts after sevoflurane treatment were detected only in chimeric mice, which expressed Adora2b exclusively on leukocytes. The Adora2b on hematopoietic and non-hematopoietic cells was required to improve the permeability after sevoflurane inhalation. Further, sevoflurane increased the protective effects of HO-1 modulation on PMN migration and microvascular permeability. These protective effects were abrogated by specific HO-1 inhibition. In conclusion, our data revealed new insights into the protective mechanisms of sevoflurane application during acute pulmonary inflammation and the link between sevoflurane and Adora2b, and HO-1 signaling, respectively.

Nephrogenic Diabetes Insipidus following an Off-Label Administration of Sevoflurane for Prolonged Sedation in a COVID-19 Patient and Possible Influence on Aquaporin-2 Renal Expression

During the recent COVID-19 pandemic, the rapidly progressive shortage of intravenous sedative drugs led numerous intensive care units to look for potential alternatives in patients requiring mechanical ventilation for severe acute respiratory distress syndrome (ARDS). Inhalational sedation using the AnaConDa® device for sevoflurane administration is a possible option. In a 54-year-old COVID-19 patient with severe ARDS requiring extracorporeal membranous oxygenation (ECMO), sevoflurane on AnaConDa® device was administered for 8 days but was complicated by the development of nephrogenic diabetes insipidus (NDI). Other causes of NDI or central diabetes insipidus were reasonably excluded, as in other previously published cases of NDI in ICU patients receiving prolonged sevoflurane-based sedation. In addition, the postmortem examination suggested a lower expression of aquaporin-2 in renal tubules. This observation should prompt further investigations to elucidate the role of aquaporin-2 in sevoflurane-related NDI. Inhaled isoflurane sedation is a possible alternative.

Intensive care nurses' experiences using volatile anaesthetics in the intensive care unit: An exploratory study

OBJECTIVE

To explore the experiences intensive care nurses have with volatile anaesthetics in the intensive care unit.

RESEARCH METHODOLOGY AND DESIGN

A qualitative exploratory and descriptive design was used. Data were collected in 2019 from individual interviews with nine intensive care nurses, who were recruited using purposive sampling. Data were analysed using systematic text condensation.

SETTING

The study was undertaken in two general intensive care units from different university hospitals in Norway where volatile anaesthetics were utilised.

FINDINGS

Three categories emerged from the data analysis: experiencing the benefits of volatile anaesthetics; coping with unfamiliarity in handling volatile anaesthetics; and meeting challenges related to volatile anaesthetics in practice.

CONCLUSION

The intensive care nurses had positive experiences related to administering volatile anaesthetics in the intensive care unit and responded positively to the prospect of using it more often. Because volatile anaesthetics were rarely used in their units, the participants felt uncertain regarding its use due to unfamiliarity. Collegial support and guidelines were perceived as pivotal in helping them cope with this uncertainty. The participants also experienced several challenges in using volatile anaesthetics in the intensive care unit, with ambient pollution being regarded as the main challenge.

Effect of sedation with inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults: a systematic review protocol

INTRODUCTION

The COVID-19 pandemic has renewed interest in the use of inhaled anaesthetics for sedation of ventilated critically ill patients. Preliminary data show that inhaled anaesthetics reduce lung inflammation, time to extubation and intensive care unit length of stay compared with intravenous sedatives. However, the impact of inhaled anaesthetics on cognitive and psychiatric outcomes is not well described in this setting. Randomised controlled trials are underway to establish if inhaled anaesthetics affect these and other patient and health system outcomes. Our aim is to summarise the known effects of inhaled sedatives on cognitive and psychiatric outcomes.

METHODS AND ANALYSIS

In this systematic review, we will use MEDLINE, EMBASE, and PsycINFO to identify studies from 1970 to 2021 that assessed cognitive and psychiatric outcomes in critically ill adult patients sedated with inhaled anaesthetics. We will include case series, observational and cohort studies and randomised controlled trials. We will exclude case studies due to the heterogeneity of reporting in these studies. For randomised controlled trials comparing inhaled to intravenous sedation, we will report cognitive and psychiatric outcomes for both study arms. Studies will be selected based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Data will be extracted using a standardised data extraction tool by two independent reviewers. Studies will be assessed for bias using the Cochrane risk of bias tool for randomised controlled trials, or the Newcastle-Ottawa Scale for cohort and case-control studies. Findings will be reported according to outcome and descriptive statistics will be used to illustrate findings in a narrative fashion.

ETHICS AND DISSEMINATION

The systematic review uses published data and therefore does not require ethics approval. Results will be disseminated via publication in peer-reviewed journals and presentation at conferences related to the field.

PROSPERO REGISTRATION NUMBER

CRD42021236455.

TIVA versus Inhalational Agents for Pediatric Cardiac Intensive Care

The field of pediatric intensive care has come a long way, especially with the recognition that adequate sedation and analgesia form an imperative cornerstone of patient management. With various drugs available for the same, the debate continues as to which is the better: total intravenous anesthesia (TIVA) or inhalational agents. While each have their own advantages and disadvantages, in the present era of balance toward the IV agents, we should not forget the edge our volatile agents (VAs) might have in special scenarios. And ultimately as anesthesiologists, let us not forget that be it knob and dial, or syringe and plunger, our aim is to put pain to sleep and awaken a new faith to breathe.

Sevoflurane Exerts Protective Effects in Murine Peritonitis-induced Sepsis via Hypoxia-inducible Factor 1α/Adenosine A2B Receptor Signaling

BACKGROUND

Sepsis is one of the leading causes of mortality in intensive care units, and sedation in the intensive care unit during sepsis is usually performed intravenously. The inhalative anesthetic sevoflurane has been shown to elicit protective effects in various inflammatory studies, but its role in peritonitis-induced sepsis remains elusive. The hypothesis was that sevoflurane controls the neutrophil infiltration by stabilization of hypoxia-inducible factor 1α and elevated adenosine A2B receptor expression.

METHODS

In mouse models of zymosan- and fecal-induced peritonitis, male mice were anesthetized with sevoflurane (2 volume percent, 30 min) after the onset of inflammation. Control animals received the solvent saline. The neutrophil counts and adhesion molecules on neutrophils in the peritoneal lavage of wild-type, adenosine A2B receptor -/-, and chimeric animals were determined by flow cytometry 4 h after stimulation. Cytokines and protein release were determined in the lavage. Further, the adenosine A2B receptor and its transcription factor hypoxia-inducible factor 1α were evaluated by real-time polymerase chain reaction and Western blot analysis 4 h after stimulation.

RESULTS

Sevoflurane reduced the neutrophil counts in the peritoneal lavage (mean ± SD, 25 ± 17 × 105vs. 12 ± 7 × 105 neutrophils; P = 0.004; n = 19/17) by lower expression of various adhesion molecules on neutrophils of wild-type animals but not of adenosine A2B receptor -/- animals. The cytokines concentration (means ± SD, tumor necrosis factor α [pg/ml], 523 ± 227 vs. 281 ± 101; P = 0.002; n = 9/9) and protein extravasation (mean ± SD [mg/ml], 1.4 ± 0.3 vs. 0.8 ± 0.4; P = 0.002; n = 12/11) were also lower after sevoflurane only in the wild-type mice. Chimeric mice showed the required expression of the adenosine A2B receptor on the hematopoietic and nonhematopoietic compartments for the protective effects of the anesthetic. Sevoflurane induced the expression of hypoxia-inducible factor 1α and adenosine A2B receptor in the intestine, liver, and lung.

CONCLUSIONS

Sevoflurane exerts various protective effects in two murine peritonitis-induced sepsis models. These protective effects were linked with a functional adenosine A2B receptor.

EDITOR’S PERSPECTIVE

Comparison of isoflurane and propofol sedation in critically ill COVID-19 patients-a retrospective chart review

Purpose

In this retrospective study, we compared inhaled sedation with isoflurane to intravenous propofol in invasively ventilated COVID-19 patients with ARDS (Acute Respiratory Distress Syndrome).

Methods

Charts of all 20 patients with COVID-19 ARDS admitted to the ICU of a German University Hospital during the first wave of the pandemic between 22/03/2020 and 21/04/2020 were reviewed. Among screened 333 days, isoflurane was used in 97 days, while in 187 days, propofol was used for 12 h or more. The effect and dose of these two sedatives were compared. Mixed sedation days were excluded.

Results

Patients’ age (median [interquartile range]) was 64 (60–68) years. They were invasively ventilated for 36 [21–50] days. End-tidal isoflurane concentrations were high (0.96 ± 0.41 Vol %); multiple linear regression yielded the ratio (isoflurane infusion rate)/(minute ventilation) as the single best predictor. Infusion rates were decreased under ECMO (3.5 ± 1.4 versus 7.1 ± 3.2 ml∙h⁻¹; p < 0.001). In five patients, the maximum recommended dose of propofol of 4 mg∙hour⁻¹∙kg⁻¹ABW was exceeded on several days. On isoflurane compared to propofol days, neuro-muscular blocking agents (NMBAs) were used less frequently (11% versus 21%; p < 0.05), as were co-sedatives (7% versus 31%, p < 0.001); daily opioid doses were lower (720 [720–960] versus 1080 [720–1620] mg morphine equivalents, p < 0.001); and RASS scores indicated deeper levels of sedation (− 4.0 [− 4.0 to − 3.0] versus − 3.0 [− 3.6 to − 2.5]; p < 0.01).

Conclusion

Isoflurane provided sufficient sedation with less NMBAs, less polypharmacy and lower opioid doses compared to propofol. High doses of both drugs were needed in severely ill COVID-19 patients.

Sedation in the Intensive Care Unit

Purpose of Review

This narrative review illustrates literature over the last 5 years relating to sedation delivery to mechanically ventilated adult patients in intensive care units.

Recent Findings

There has been an increase in dexmedetomidine-related publications but although systematic reviews suggest dexmedetomidine reduces delirium, agitation, and length of stay, clinical trials have not supported these findings. It is likely to be useful for the managing patients with persisting agitation. Guidelines continue to recommend lightly sedating patients but considerable variation remains in clinical practice and in research trials. Protocols with no sedative infusions and morphine boluses as needed are feasible and safe, while educational interventions can decrease sedation-related adverse events.

Summary

Research trials have mainly focused on individual drugs rather than practice. Given evidence is slow to translate into practice; work is needed to understand and respond to the concerns of clinicians regarding deep sedation and agitation.

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

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.

Standard Sedation and Sedation With Isoflurane in Mechanically Ventilated Patients With Coronavirus Disease 2019

Objectives:

To describe sedative and analgesic drug utilization in a cohort of critically ill patients with coronavirus disease 2019 and compare standard sedation with an alternative approach using inhaled isoflurane.

Design:

This was a retrospective cohort study designed to compare doses of sedatives between ICU patients receiving standard IV sedation and patients receiving mixed sedation including inhaled isoflurane. Data were obtained from electronic medical records.

Setting:

ICU at large academic medical center where mechanical ventilation was delivered with Draeger Apollo (Draeger Medical, Telford, PA) anesthesia machines.

Patients:

Consecutive adult patients (≥ 18 yr) with confirmed coronavirus disease 2019 admitted to ICU between April 2, 2020, and May 4, 2020.

Interventions:

None.

Measurements and Main Results:

Thirty-five mechanically ventilated patients were included in the study, with a mean (sd) age of 59.4 (12.8) years. Twenty-three patients (65.7%) were men. Seventeen patients (48.6%) received standard IV sedation, whereas 18 (51.4%) also received isoflurane. The mean duration of mechanical ventilation (sd) was 23.3 (11.6) days in the standard sedation group and 23.8 (12.5) days in the isoflurane group. Mean (sd) duration of isoflurane exposure was 5.61 (2.99) days, representing 29.1% of total sedation time (sd, 20.4). Cumulative opioid exposure did not differ between the standard sedation and isoflurane sedation groups (mean morphine milligram equivalent 6668 [sd, 1,346] vs 6678 [sd, 2,000] mg). However, the initiation of isoflurane in patients was associated with decreased utilization of propofol (mean daily amount 3,656 [sd, 1,635] before vs 950 [sd, 1,804] mg during isoflurane) and hydromorphone (mean daily amount 48 [sd, 30] before vs 23 [sd, 27] mg).

Conclusions:

In the subjects that received isoflurane, its use was associated with significant decreases in propofol and hydromorphone infusions.

Inased (inhaled sedation in ICU) trial protocol: a multicentre randomised open-label trial

INTRODUCTION

The use of sedation in intensive care units (ICUs) is necessary and ubiquitous. The impact of sedation strategy on outcome, particularly when delivered early after initiation of mechanical ventilation, is unknown. Evidence is increasing that volatile anaesthetic agents could be associated with better outcome. Their use in delirium prevention is unknown.

METHODS AND ANALYSIS

This study is an investigator-initiated, prospective, multicentre, two-arm, randomised, control, open-trial comparing inhaled sedation strategy versus intravenous sedation strategy in mechanically ventilated patients in ICU. Two hundred and fifty patients will be randomly assigned to the intravenous sedation group or inhaled sedation group, with a 1:1 ratio in two groups according to the sedation strategy. The primary outcome is the occurrence of delirium assessed using two times a day confusion assessment method for the ICU (CAM-ICU). Secondary outcomes include cognitive and functional outcomes at 3 and 12 months.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Ethics Committee (CPP Ouest) and national authorities (ANSM). The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04341350.

Volatile Sedation for Acute Respiratory Distress Syndrome Patients on Venovenous Extracorporeal Membrane Oxygenation and Ultraprotective Ventilation

Supplemental Digital Content is available in the text.

Patients on extracorporeal support for severe acute respiratory distress syndrome may require a prolonged period of deep sedation. In these patients, volatile sedation may represent a valid alternative to IV drugs. The aim of our study was to describe the feasibility of volatile sedation in a large cohort of acute respiratory distress syndrome patients undergoing venovenous extracorporeal membrane oxygenation and ultraprotective ventilation.

Sedating Mechanically Ventilated COVID-19 Patients with Volatile Anesthetics: Insights on the Last-Minute Potential Weapons

Coronavirus Disease 2019 (COVID-19) has spread globally with the number of cases exceeding seventy million. Although trials on potential treatments of COVID-19 Acute Respiratory Distress Syndrome (ARDS) are promising, the introduction of an effective therapeutic intervention seems elusive. In this review, we explored the potential therapeutic role of volatile anesthetics during mechanical ventilation in the late stages of the disease. COVID-19 is thought to hit the human body via five major mechanisms: direct viral damage, immune overactivation, capillary thrombosis, loss of alveolar capillary membrane integrity, and decreased tissue oxygenation. The overproduction of pro-inflammatory cytokines will eventually lead to the accumulation of inflammatory cells in the lungs, which will lead to ARDS requiring mechanical ventilation. Respiratory failure resulting from ARDS is thought to be the most common cause of death in COVID-19. The literature suggests that these effects could be directly countered by using volatile anesthetics for sedation. These agents possess multiple properties that affect viral replication, immunity, and coagulation. They also have proven benefits at the molecular, cellular, and tissue levels. Based on the comprehensive understanding of the literature, short-term sedation with volatile anesthetics may be beneficial in severe stages of COVID-19 ARDS and trials to study their effects should be encouraged.