Smischney, Nathan J.

Abstract Introduction Sedation is routinely administered to facilitate comfort and tolerance of life support for critically ill adults dependent on invasive mechanical ventilation. Isoflurane, a widely used anesthetic during surgery, has properties that may also benefit ICU patients requiring continuous sedation. However, efficacy as a sedative and safety in this population is not well established. Methods We conducted two identically designed multicenter randomized trials, INSPIRE ICU1 and INSPIRE ICU2, at hospitals across the US. Ventilator-dependent adults were randomly assigned in a 1.5:1 ratio to receive either inhaled isoflurane or intravenous propofol as the first-line sedative for up to 48 ± 6 hours, targeting a sedation depth between Richmond agitation-sedation scale (RASS) -1 (drowsy) to -4 (responsive only to physical stimuli). Isoflurane was administered via an anesthetic conserving device (Sedaconda ACD-S). In both arms, opioids were permitted at the lowest dose required to achieve freedom from pain. The primary outcome was the percentage of time at target sedation level, assessed as a noninferiority outcome with pre-specified margin of 15%. Secondary outcomes included opioid exposure, wake-up time after end of treatment, time to extubation, and proportion of time with spontaneous breathing effort. Results A total of 470 combined participants were included in the two trials. In each trial, 142 patients were randomly assigned to isoflurane and 93 to propofol. In INSPIRE ICU1, percentage of time within target sedation depth was 77.1 [53.2, 89.9] % with isoflurane and 80.9 [58.2, 96.4] % with propofol (difference -1.5 [-8.9, >99] %; p < 0.01 for noninferiority). In INSPIRE ICU2, percentage of time within target sedation depth was 72.6 [66.4, 78.9] % with isoflurane and 74.5 [67.5, 81.5] % with propofol (difference -1.9 [-9.4, >99] %; p < 0.01 for noninferiority). In both trials, patients assigned to isoflurane received significantly less opioid, measured as fentanyl equivalents, during the treatment period. In INSPIRE ICU2, participants receiving isoflurane were significantly likelier to exhibit spontaneous breathing efforts, but this finding was not replicated in INSPIRE ICU1. There were no significant differences in time to wake-up or time to extubation between groups in either trial. No episodes of malignant hyperthermia or propofol infusion syndrome were reported. Adverse events were comparable in type and frequency between groups. Conclusions In two US multicenter trials, isoflurane was noninferior to propofol for maintaining target sedation depth in adults undergoing invasive ventilation, and was associated with significantly lower opioid exposure. (NCT05327296, NCT05312385) This abstract is funded by: Sedana Medical

While the field of anesthesiology has a storied history of innovation, especially related to patient safety, contemporary anesthesiologists face growing barriers to innovation from complex regulatory requirements and financial constraints. The Biodesign framework offers a systematic approach to medical technology development that can be applied to the perioperative space to address these challenges. This process begins with identification and screening of high-value clinical needs, followed by generation and evaluation of potential solutions, and culminates in strategy development, business planning, and fundraising. Each stage is designed to guide clinicians from early observation through translation into viable technologies. By adopting this structured method, anesthesiologists are well-positioned to transform clinical insights into scalable solutions, ensuring the specialty continues to advance patient safety and care in the face of evolving clinical demands.

OBJECTIVE: Volatile anesthetics (VAs) are gaining renewed interest as a sedation strategy in the intensive care, offering an alternative to traditional IV agents. VAs provide several pharmacologic advantages, including rapid onset and offset, minimal systemic metabolism, and favorable recovery profiles. Advances in delivery systems enabled the safe and practical administration of volatile agents in the ICU. Thus, we aimed to describe the pharmacology and safety aspects of inhaled agents as well as the systems designed to deliver VAs in the ICU. DATA SOURCES: Relevant literature was identified through PubMed and MEDLINE databases. STUDY SELECTION: Original research, review articles, commentaries, and guidelines addressing safety, efficacy, and use of VAs in adult ICU patients were included. DATA EXTRACTION: Studies were reviewed by the authors, with key findings summarized and organized by pharmacologic properties, delivery systems, and safety domains. DATA SYNTHESIS: VAs are halogenated hydrocarbons whose mechanism of action is not fully understood. Although the CNS is the primary site of action, the end-tidal concentration of exhaled anesthetic is used to monitor clinical effects such as immobility to a noxious stimulus. Inhaled agents have unique pharmacokinetics, minimal metabolisms, and distinct recovery. The side effect profile is also unique, with malignant hyperthermia being the most feared, yet rare complication. Two systems for inhalational sedation delivery are available internationally, with one currently under evaluation in the United States. The systems are composed of a miniature vaporizer, delivery controller, and a monitor. The systems have distinct safety considerations, such as tidal volume limits. CONCLUSIONS: VAs can be used as sedative agents in the ICU. This article comprehensively reviews the pharmacology of VAs along with their safety profile and describes the structure and function of miniature vaporizers currently available on the world market.

Summary Introduction Postoperative delirium is a common complication following cardiac surgery. Despite its known impact on patient outcomes, effective preventative strategies remain elusive. We aimed to perform a comprehensive Bayesian network meta‐analysis of randomised controlled trials assessing the effect of pharmacological interventions on the incidence of postoperative delirium. Methods Databases were searched from inception to September 2024. Our search was updated in January 2025. Eligible studies included randomised controlled trials reporting the incidence of postoperative delirium in patients having cardiac surgery treated with pharmacological interventions. Bayesian models were used to estimate risk ratios (RR) and mean differences with 95%CrI through Markov chain Monte Carlo. Interventions were ranked using the surface under the cumulative ranking curve. Sensitivity analyses and grading of recommendations, assessment, development and evaluation assessment were conducted to evaluate the robustness and certainty of evidence. Results Seventy‐nine randomised controlled trials comprising 24,827 patients were included, with 29 pharmacological interventions compared. Dexmedetomidine combined with melatonin was the most effective intervention, reducing the incidence of postoperative delirium compared with placebo (risk ratio 0.31, 95%CrI 0.13–0.69; low certainty). Dexmedetomidine with melatonin also significantly decreased intensive care unit stay (2.4 days, 95%CrI ‐3.50–1.10) and hospital stay (1.32 days, 95%CrI ‐2.09 to ‐0.57). Other interventions, including ketamine and risperidone, showed potential efficacy but with low or very low certainty of evidence. Discussion We identified dexmedetomidine with melatonin as the most effective pharmacological strategy for preventing postoperative delirium following cardiac surgery. Whilst these findings highlight potential benefits, the low certainty of evidence underscores the need for more high‐quality primary evidence.

Objective Specific sedative hypnotic agents, administered to facilitate endotracheal intubation (ETI) in critically ill adults, may lead to adverse outcomes such as peri-intubation cardiovascular collapse. However, little is known from systematic investigations of the impact these individual agents have on cardiovascular function or other clinical outcomes. Data sources MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, Scopus and Web of science databases. Study selection We conducted a systematic search for randomized and non-randomized studies that evaluated adult (≥18 years) critically ill patients who were sedated to facilitate ETI with ketamine, propofol, ketamine/propofol, etomidate, or a benzodiazepine and who had data on peri-intubation hemodynamics and at least one other outcome involving acute kidney injury, delirium, opioid use, intubation difficulty, sequential organ failure assessment, length of stay, or mortality. Eighty-five studies were identified for eligibility assessment with 23 included in the analysis. Data extraction Two reviewers independently screened articles, extracted data from selected articles, and assessed risk of bias using ROBINS-I for observational studies and revised Cochrane Risk of Bias tool for randomized controlled trials. Data synthesis Acute cardiovascular dysfunction (peri-intubation hemodynamic instability and/or cardiac arrest) was similar between etomidate and ketamine with more events seen when propofol versus non-propofol sedation was administered. However, exploratory meta-analysis demonstrated no difference between etomidate and ketamine (OR 1.05 [95%CI 0.60-1.84]) or between etomidate and propofol (OR 0.91 [95%CI 0.33-2.46]). Compared to ketamine, etomidate demonstrated lower survival to hospital discharge in the included studies in exploratory meta-analysis OR 0.76 (95%CI 0.62-0.92). Limited data existed for other outcomes with no discernible differences between sedative agents. Conclusions Acute cardiovascular dysfunction was more common when propofol, as compared to non-propofol sedation, was administered, although not statistically significant in exploratory meta-analysis. In addition, etomidate conferred lower survival to hospital discharge versus non-etomidate sedation, which was confirmed in exploratory meta-analysis of etomidate versus ketamine.

Objective Extracorporeal cardiopulmonary resuscitation (ECPR) utilizes veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in cardiac arrest patients to reduce the risk of mortality and multiorgan dysfunction from systemic hypoperfusion. We aimed to compare clinical outcomes of patients receiving ECPR versus conventional cardiopulmonary resuscitation (CCPR) for refractory cardiac arrest. Data Sources This was a systematic review and meta-analysis. A librarian searched the main databases, Ovid MEDLINE (including epub ahead of print, in-process & other non-indexed citations), Ovid EMBASE and Ovid Cochrane Central Register of Controlled Trials from inception through July 2024. Study Selection We included randomized controlled trials and observational studies that compared the outcomes of ECPR to CCPR in cardiac arrest patients. Primary outcomes were neurological sequelae and survival. Data Extraction We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two reviewers independently screened articles, extracted data on selected articles and performed risk of bias assessments using ROBINS-I for non-randomized controlled trials and the revised Cochrane risk of bias tool for randomized controlled trials with disagreements settled by a third independent reviewer. Data Synthesis Out of 3458 studies identified and screened, 28 studies including 304,360 cardiac arrest patients met eligibility criteria and were included. Survival at hospital discharge was 20% for ECPR versus 3.3% for CCPR (OR 0.48 [CI 0.27, 0.84]). Favorable neurological outcome at hospital discharge was 11.8% for ECPR versus 1.9% for CCPR (OR 0.41 [CI 0.17, 1.01]). Complications from bleeding were ten times higher in the ECPR group (35.3% vs 3.7%; OR 0.08 [0.03, 0.24]). Conclusions ECPR appeared to be superior to CCPR for improved neurological outcome and survival in cardiac arrest patients, although bleeding was increased. There was large heterogeneity in the included studies and outcomes reported. Future prospective studies may improve the identification of subgroups of patients that will benefit most from ECPR. Systematic review and meta-analysis registration: PROSPERO - CRD42023394128.

Background Based on current evidence, there appears to be an association between peri-intubation hypotension and patient morbidity and mortality. Studies have identified shock indices as possible pre-intubation risk factors for peri-intubation hypotension. Thus, we sought to evaluate the association between shock index (SI), modified shock index (MSI), and diastolic shock index (DSI) and peri-intubation hypotension along with other outcomes. Methods The present study is a sub-study of a randomized controlled trial involving critically ill patients undergoing intubation. We defined peri-intubation hypotension as a decrease in mean arterial pressure <65 mm Hg and/or a reduction of 40% from baseline; or the initiation of, or increase in infusion dosage of, any vasopressor medication (bolus or infusion) during the 30-min period following intubation. SI, MSI, and DSI were analyzed as continuous variables and categorically using pre-established cut-offs. We also explored the effect of age on shock indices. Results A total of 151 patients were included in the analysis. Mean pre-intubation SI was 1.0 ± 0.3, MSI 1.5 ± 0.5, and DSI 1.9 ± 0.7. Increasing SI, MSI, and DSI were significantly associated with peri-intubation hypotension (OR [95% CI] per 0.1 increase = 1.16 [1.04, 1.30], P = .009 for SI; 1.14 [1.05, 1.24], P = .003 for MSI; and 1.11 [1.04, 1.19], P = .003 for DSI). The area under the ROC curves did not differ across shock indices (0.66 vs 0.67 vs 0.69 for SI, MSI, and DSI respectively; P = .586). Increasing SI, MSI, and DSI were significantly associated with worse sequential organ failure assessment (SOFA) score (spearman rank correlation: r = 0.30, r = 0.40, and r = 0.45 for SI, MSI, and DSI, respectively, all P < .001) but not with other outcomes. There was no significant impact when incorporating age. Conclusions Increasing SI, MSI, and DSI were all significantly associated with peri-intubation hypotension and worse SOFA scores but not with other outcomes. Shock indices remain a useful bedside tool to assess the potential likelihood of peri-intubation hypotension. Trial registration ClinicalTrials.gov identifier - NCT02105415

Background: Cardiovascular instability occurring during endotracheal intubation (ETI) in the critically ill is a commonly recognized phenomenon. However, this complication has not been evaluated in terms of the physiological cause (ie, decreased preload, contractility, or afterload) leading to the instability. Thus, the aim of the current investigation was to describe the hemodynamics occurring during ETI with noninvasive physiologic monitoring and to collect preliminary data on the hemodynamic effects of induction agents and positive pressure ventilation. Methods: A multicenter prospective study enrolling adult (≥18 years) critically ill patients undergoing ETI with noninvasive cardiac output monitoring in a medical/surgical intensive care unit from June 2018 to May 2019 was conducted. This study used the Cheetah Medical noninvasive cardiac output monitor to collect hemodynamic data during the peri-intubation period. Additional data collected included baseline characteristics such as illness severity, peri-intubation pharmacologic administration, and mechanical ventilation settings. Results: From the original 27 patients, only 19 (70%) patients had complete data and were included in the final analysis. Propofol was the most common sedative 8 (42%) followed by ketamine 6 (32%) and etomidate 5 (26%). Patients given propofol demonstrated a decrease in total peripheral resistance index (delta change [dynes × s/cm −5 /m 2 ]: −2.7 ± 778.2) but stabilization in cardiac index (delta change (L/min/m 2 ]: 0.1 ± 1.5) while etomidate and ketamine demonstrated increases in total peripheral resistance index (etomidate delta change [dynes × s/cm −5 /m 2 ]: 302.1 ± 414.3; ketamine delta change [dynes × s/cm −5 /m 2 ]: 278.7 ± 418.9) but only etomidate resulted in a decrease in cardiac index (delta change [L/min/m 2 ]: −0.3 ± 0.5). Positive pressure ventilation resulted in minimal changes to hemodynamics during ETI. Conclusions: The current study demonstrates that although propofol administration leads to a decrease in total peripheral resistance index, cardiac index is maintained while etomidate leads to a decrease in cardiac index with both etomidate and ketamine increasing total peripheral resistance index. These hemodynamic profiles are minimally affected by positive pressure ventilation. Study registration: ClinicalTrials.gov ID, NCT03525743.

Introduction High-dose catecholamines can impair hypoxic pulmonary vasoconstriction and increase shunt fraction. We aimed to determine if Angiotensin II (Ang-2) is associated with improved PaO 2 /FiO 2 and SpO 2 /FiO 2 in patients in shock. Methods Adult patients at four tertiary care centers and one community hospital in the United States who received Ang-2 from July 2018-September 2020 were included in this retrospective, observational cohort study. PaO 2 , SpO 2 , and FiO 2 were measured at 13 timepoints during the 48-h before and after Ang-2 initiation. Piecewise linear mixed models of PaO 2 /FiO 2 and SpO 2 /FiO 2 were created to evaluate hourly changes in oxygenation after Ang-2 initiation. The difference in the proportion of patients with PaO 2 /FiO 2 ≤ 300 mm Hg at the time of Ang-2 initiation and 48 h after was also examined. Results The study included 254 patients. In the 48 h prior to Ang-2 initiation, oxygenation was significantly declining (hourly PaO 2 /FiO 2 change −4.7 mm Hg/hr, 95% CI − 6.0 to −3.5, p < .001; hourly SpO 2 /FiO 2 change −3.1/hr, 95% CI−3.7 to −2.4, p < .001). Ang-2 treatment was associated with significant improvements in PaO 2 /FiO 2 and SpO 2 /FiO 2 in the 48-h after initiation (hourly PaO 2 /FiO 2 change +1.5 mm Hg/hr, 95% CI 0.5-2.5, p = .003; hourly SpO 2 /FiO 2 change +0.9/hr, 95% CI 0.5-1.2, p < .001). The difference in the hourly change in oxygenation before and after Ang-2 initiation was also significant ( p interaction < 0.001 for both PaO 2 /FiO 2 and SpO 2 /FiO 2 ). This improvement was associated with significantly fewer patients having a PaO 2 /FiO 2 ≤ 300 mm Hg at 48 h compared to baseline (mean difference −14.9%, 95% CI −25.3% to −4.6%, p = .011). Subgroup analysis found that patients with either a baseline PaO 2 /FiO 2 ≤ 300 mm Hg or a norepinephrine-equivalent dose requirement >0.2 µg/kg/min had the greatest associations with oxygenation improvement. Conclusions Ang-2 is associated with improved PaO 2 /FiO 2 and SpO 2 /FiO 2 . The mechanisms for this improvement are not entirely clear but may be due to catecholamine-sparing effect or may also be related to improved ventilation-perfusion matching, intrapulmonary shunt, or oxygen delivery.