Search

The aim of this case series report is to provide a new topical view of styletubation (video intubating stylet technique) in obese patients undergoing bariatric surgeries. In contrast to various conventional direct laryngoscopes (DLs), videolaryngoscopes (VLs) have been applied in such obese populations with potentially difficult airway complications. The safety and effectiveness of VLs have been repeatedly studied, and the superiority of VLs has then been observed in and advocated for routine use. In this article, among our vast use experiences with styletubation (more than 54,998 patients since 2016) for first-line routine tracheal intubation, we present the unique experience to apply the styletubation technique in obese patients undergoing bariatric surgery. Consistent with the experiences applied in other patient populations, we found the styletubation technique itself to be swift (the time to intubate from 5 s to 24 s), smooth (first-attempt success rate: 100%), safe (no airway complications), and easy (high subjective satisfaction). The learning curve is steep, but competency can be enhanced if technical pitfalls can be avoided. We, therefore, propose that the styletubation technique can be feasibly and routinely applied as a first-line airway modality in obese patients undergoing bariatric surgery. [ABSTRACT FROM AUTHOR]

Laryngoscopy for tracheal intubation has been developed for many decades. Among various conventional laryngoscopes, videolaryngoscopes (VLs) have been applied in different patient populations, including difficult airways. The safety and effectiveness of VLs have been repeatedly studied in both normal and difficult airways. The superiority of VLs then has been observed and is advocated as the standard of care. In contrast to laryngoscopy, the development of video-assisted intubating stylet (VS, also named as styletubation) was noticed two decades ago. Since then, sporadic clinical experiences of use have appeared in the literature. In this review article, we presented our vast use experiences of the styletubation (more than 55,000 patients since 2016). We found this technique to be swift (the time to intubate from 3 s to 10 s), smooth (first-attempt success rate: 100%), safe (no airway complications), and easy (high subjective satisfaction and fast learning curve for the novice trainees) in both normal and difficult airway scenarios. We, therefore, propose that the styletubation technique can be feasibly applied as universal routine use for tracheal intubation. [ABSTRACT FROM AUTHOR]

Open aortic arch surgery incurs frequent neurologic complications and high mortality. The disease processes of aortic aneurysm and acute aortic dissection, and the physiological trespass of cardiopulmonary bypass and hypothermic circulatory arrest (CA), can engender neurologic dysfunction such as postoperative stroke and delirium. While deep hypothermic CA (with and without retrograde cerebral perfusion) is the major strategy for brain protection, moderate hypothermic CA with antegrade cerebral perfusion has comparable or better outcomes. Classes of neurologic complications in aortic arch surgery were defined three decades ago. In 2021, the Valve Academic Research Consortium recommended new endpoints for assessing neurologic outcomes of transcatheter and surgical aortic valve procedures. Those parameters include neuroimaging biomarkers. Overt central nervous system (CNS) injury is the severe form and delirium is the common clinical presentation. Covert CNS injury, evidenced on brain imaging, is prevalent in patients following transcatheter aortic valve replacement (TAVR). The new definition for neurologic dysfunction after TAVR could serve in the classification of neurologic dysfunction in aortic arch surgery. [ABSTRACT FROM AUTHOR]

Spin- and angle-resolved photoemission spectroscopy ("spin-ARPES") is a powerful technique for probing the spin degree-of-freedom in materials with nontrivial topology, magnetism, and strong correlations. Spin-ARPES faces severe experimental challenges compared to conventional ARPES attributed to the dramatically lower efficiency of its detection mechanism, making it crucial for instrumentation developments that improve the overall performance of the technique. In this paper, we demonstrate the functionality of our spin-ARPES setup based on time-of-flight spectroscopy and introduce our recent development of an electrostatic deflector mode to map out spin-resolved band structures without sample rotation. We demonstrate the functionality by presenting the spin-resolved spectra of the topological insulator Bi2Te3 and describe in detail the spectrum calibrations based on numerical simulations. By implementing the deflector mode, we minimize the need for sample rotation during measurements, hence improving the overall efficiency of experiments on small or inhomogeneous samples. [ABSTRACT FROM AUTHOR]

Direct laryngoscopes and videolaryngoscopes are the dominant endotracheal intubation tools. The styletubation technique (using a video-assisted intubating stylet) has shown its advantages in terms of short intubation time, high success rate, less required stimulation, and operator satisfaction. The learning curve can be steep but is easily overcome if technical pitfalls are avoided. Conditions that make styletubation challenging include secretions/blood, short/stiff neck, restricted mouth opening and cervical spine mobility, anatomical abnormalities over head and neck regions, obesity, etc. In this clinical report, we present the effectiveness and efficiency of the routine use of the styletubation for tracheal intubation in a super-super-obese patient (BMI 103 kg/m2) undergoing bariatric surgery with laparoscopic sleeve gastrectomy. [ABSTRACT FROM AUTHOR]

Direct laryngoscopy and videolaryngoscopy are currently the dominant tools for endotracheal intubation. However, the video-assisted intubating stylet, a type of videolaryngoscopy, has been shown to offer some advantages over these tools, such as rapid intubation time, high first-attempt success rates, less airway stimulation, and high subjective satisfaction. On the other hand, this optical intubating technique also has some technical limitations that need to be addressed, including camera lens fogging, airway path disorientation, and obscured visibility due to secretions. In this clinical report, we describe an approach that improves the visibility of the glottis by introducing a suctioning catheter into the nasopharyngeal airway to enhance the efficiency and accuracy of using the intubating stylet technique for tracheal intubation. [ABSTRACT FROM AUTHOR]

Direct laryngoscopy (DL) and videolaryngoscopy (VL) have been the most commonly used airway management modalities in the last several decades. Meanwhile, various optional airway tools (e.g., supraglottic devices, fiberoptic bronchoscopes) have been used for alternative rescue modalities when anticipated or unexpected difficulties in airway management has occurred. In recent decades, optical stylets and video-assisted intubating stylets have become another option for difficult airway scenarios. In contrast to other approaches, we have adopted the Shikani video-assisted intubating stylet technique (VS) for both routine and difficult airway management scenarios. In this case series report, we present the video-twin technique, combining a videolaryngoscope with a video-assisted intubating stylet in various clinical case scenarios. We propose that such a combination is easy to learn and employ and is particularly beneficial in situations where an expected difficult airway (EDA) is encountered. [ABSTRACT FROM AUTHOR]

Among all the proposed predictors of difficult intubation defined by the intubation difficulty scale, head and neck movement (motility) stands out and plays as a crucial factor in determining the success rate and the degree of ease on endotracheal intubation. Aside from other airway tools (e.g., supraglottic airway devices), optical devices have been developed and applied for more than two decades and have shown their superiority to conventional direct laryngoscopes in many clinical scenarios and settings. Although awake/asleep flexible fiberoptic bronchoscopy is still the gold standard in patients with unstable cervical spines immobilized with a rigid cervical collar or a halo neck brace, videolaryngoscopy has been repeatedly demonstrated to be advantageous. In this brief report, for the first time, we present our clinical experience on the routine use of the Shikani video-assisted intubating stylet technique in patients with traumatic cervical spine injuries immobilized with a cervical stabilizer and in a patient with a stereotactic headframe for neurosurgery. Some trouble-shooting strategies for this technique are discussed. This paper demonstrates that the video-assisted intubating stylet technique is an acceptable alternative airway management method in patients with restricted or confined neck motility. [ABSTRACT FROM AUTHOR]

As the COVID-19 pandemic evolves, infection with the Omicron variants has become a serious risk to global public health. Anesthesia providers are often called upon for endotracheal intubations for COVID patients. Expedite and safe intubation can save patient's life, while minimizing the virus exposure to the anesthesia provider and personnel involved during airway intervention is very important to protect healthcare workers and conserve the medical work force. In this paper, we share clinical experience of using a video-assisted intubating stylet technique combined with a simple plastic sheet barrier placed over the patients' mouth for tracheal intubation during the Omicron crisis in Taiwan. We demonstrated that the use of an intubating stylet combined with plastic sheet barrier is swift, safe, and accurate in securing the airway in patients with COVID-19. [ABSTRACT FROM AUTHOR]

Induction of anesthesia can be challenging for patients with difficult airways and head or neck tumors. Factors that could complicate airway management include poor dentition, limited mouth opening, restricted neck motility, narrowing of oral airway space, restricted laryngeal and pharyngeal space, and obstruction of glottic regions from the tumor. Current difficult airway management guidelines include awake tracheal intubation, anesthetized tracheal intubation, or combined awake and anesthetized intubation. Video laryngoscopy is often chosen over direct laryngoscopy in patients with difficult airways because of an improved laryngeal view, higher frequency of successful intubations, higher frequency of first-attempt intubation, and fewer intubation attempts. In this case series report, we describe the video-assisted intubating stylet technique in five patients with difficult airways. We believe that the intubating stylet is a feasible and safe airway technique for anesthetized tracheal intubation in patients with an anticipated difficult airway. [ABSTRACT FROM AUTHOR]

Hospitalized older patients who undergo elective cardiac surgery with cardiopulmonary bypass are prone to postoperative delirium. Self‐reported shorter sleep and longer sleep have been associated with impaired cognition. Few data exist to guide us on whether shorter or longer sleep is associated with postoperative delirium in this hospitalized cohort. This was a prospective, single‐site, observational study of hospitalized patients (>60 years) scheduled to undergo elective major cardiac surgery with cardiopulmonary bypass (n = 16). We collected and analysed overnight polysomnography data using the Somté PSG device and assessed for delirium twice a day until postoperative day 3 using the long version of the confusion assessment method and a structured chart review. We also assessed subjective sleep quality using the Pittsburg Sleep Quality Index. The delirium median preoperative hospital stay of 9 [Q1, Q3: 7, 11] days was similar to the non‐delirium preoperative hospital stay of 7 [4, 9] days (p =.154). The incidence of delirium was 45.5% (10/22) in the entire study cohort and 50% (8/16) in the final cohort with clean polysomnography data. The preoperative delirium median total sleep time of 323.8 [Q1, Q3: 280.3, 382.1] min was longer than the non‐delirium median total sleep time of 254.3 [210.9, 278.1] min (p =.046). This was accounted for by a longer delirium median non‐rapid eye movement (REM) stage 2 sleep duration of 282.3 [229.8, 328.8] min compared to the non‐delirium median non‐REM stage 2 sleep duration of 202.5 [174.4, 208.9] min (p =.012). Markov chain modelling confirmed these findings. There were no differences in measures of sleep quality assessed by the Pittsburg Sleep Quality Index. Polysomnography measures of sleep obtained the night preceding surgery in hospitalized older patients scheduled for elective major cardiac surgery with cardiopulmonary bypass are suggestive of an association between longer sleep duration and postoperative delirium. [ABSTRACT FROM AUTHOR]

Background: Postoperative delirium (POD) is an acute altered mental state commonly encountered after cardiac surgery. The pathophysiological mechanisms underlying POD remain unclear. We aimed to identify circulating proteins significantly altered after major cardiac surgery with cardiopulmonary bypass (CPB). We also aimed to enable inferences on associations with POD. Methods: Serum and whole blood samples were collected before CPB (n = 16 patients; n = 8 with POD) and again from the same patients on postoperative day 1. All patients were clinically evaluated for POD on postoperative days 1–3. An aptamer-based proteomics platform (SOMAscan) was used to quantify serum protein abundance in patients with POD compared with non-POD controls. We also performed a lipopolysaccharide (LPS)-based in vitro functional analysis (TruCulture) on whole blood samples from patients with POD and non-POD controls to approximate surgical stress. Cytokine levels were determined using a Luminex immunoassay. Results: Cardiac surgery with CPB resulted in a significant (p adj < 0.01) change in 48.8% (637 out of 1,305) of proteins detected by SOMAscan. Gene set enrichment showed that the most impacted biological processes involved myeloid cell activation. Specifically, activation and degranulation of neutrophils were the top five highest-scoring processes. Pathway analyses with the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that metabolic enzymes, particularly those of glycolysis, were elevated in serum concentration after surgery. Several proteins were significantly increased postoperatively in patients diagnosed with POD relative to the non-POD controls, with interleukin-6 (IL-6) showing the greatest fold-change. LPS stimulation of whole blood samples confirmed these findings. Linear regression analysis showed a highly significant correlation between Confusion Assessment Method (CAM) scores and CPB-mediated changes in cGMP-inhibited 3′,5′-cyclic phosphodiesterase A (PDE3A). Conclusions: ardiac surgery with CPB resulted in inflammasome changes accompanied by unexpected increases in metabolic pathways. In exploratory analyses, we found that POD was associated with changes in the expression level of various proteins, most notably IL-6 and PDE3A. This study and ongoing protein biomarker studies will likely help quantify risk or confirm the diagnosis for POD and increase understanding of its pathophysiological mechanisms. [ABSTRACT FROM AUTHOR]

Background: In this study, we compare the clinical characteristics, intraoperative management, and postoperative outcomes of patients with acute type A aortic dissection (ATAAD) between two academic medical hospitals in the United States and China.Methods: From January 2011 to December 2017, 641 and 150 patients from Nanjing Drum Tower Hospital (NDTH) and Massachusetts General Hospital (MGH) were enrolled. Patient demographics, clinical features, surgical techniques, and postoperative outcomes were compared.Results: The annual number of patients presenting with ATAAD at MGH remained relatively stable, while the number at NDTH increased significantly over the study period. The average age was 51 years at NDTH and 61 years at MGH (P < .001). The percentage of patients with known hypertension at the two centers was similar. The time interval from onset of symptoms to diagnosis was significantly longer at NDTH than MGH (11 vs 3.5 hours; P < .001). Associated complications at presentation were more common at NDTH than MGH. More than 90% of patients (91% NDTH and 92% MGH) underwent surgery. The postoperative stroke rate was higher at MGH (12% vs 4%; P < .001); however, the 30-day mortality rate was lower (7% vs 16%; P = .006).Conclusions: There was a significant increase in the number of ATAAD at NDTH during the study period while the number at MGH remained stable. Hypertension was a common major risk factor; however, the onset of ATAAD at NDTH was nearly one decade earlier than MGH. Chinese patients tended to have more complicated preoperative pathophysiology at presentation and underwent more extensive surgical repair. [ABSTRACT FROM AUTHOR]

Background: Migration of physicians has been a cause for global concern. In China, reforms of the higher education and healthcare systems have led to a shortage of postgraduate training positions relative to the number of medical graduates. Medical graduates opt for non-clinical roles or move abroad to pursue further training and practice opportunities. The impact of this physician migration is not known. This study quantifies where Chinese migrant physicians to the U.S. were educated, where they went to practice, and how these trends have changed over time. Methods: We combined data on physician characteristics from the 2008 and 2017 American Medical Association Physician Masterfiles with demographic information from the Educational Commission for Foreign Medical Graduates. Using a repeated cross-sectional approach, we reviewed the available data, including citizenship at entry to medical school, medical school attended, practice specialty, and practice location. Results: The number of Chinese-educated physicians (CEPs) to the United States (US) has increased over the past 10 years, from 3,878 in 2008 to 5,355 in 2017 (+38.1%). The majority held Chinese citizenship at entry to medical school (98.4% vs 97.1%) with the remainder being citizens of other East Asian nations. Of the Chinese citizens identified in 2008, 913 (19.3%) attended medical school outside of China; in 2017, 376 (6.7%) attended medical school outside of China, representing a decrease of 58.8%. Overall, in 2017, four Chinese medical schools provided 32.1% of all Chinese-educated physicians in the US. Over 50% of the CEPs were practicing in Internal Medicine, Anatomic/ Clinical Pathology, Anesthesiology, Family Medicine or Neurology. Compared with all IMGs, CEPs are more likely to be Anatomic/ Clinical Pathologists and Anesthesiologists. CEPs were concentrated in several states, including New York, California and Massachusetts. In 2017, a lower proportion of CEPs in the US healthcare workforce were in residency training, compared to 2008 (13.2% vs 22.8%). Conclusions: Unlike trends from some other South Asian countries, the number of CEPs in the US has increased over the past 10 years. Migration trends may vary depending on citizenship and country of medical school training. The majority of Chinese-educated graduates come to the US from relatively few medical schools. Fewer CEPs currently in residency training might indicate lower success rates in securing GME training in the US. [ABSTRACT FROM AUTHOR]

Introduction Delirium, which is prevalent in postcardiac surgical patients, is an acute brain dysfunction characterised by disturbances in attention, awareness and cognition not explained by a pre-existing neurocognitive disorder. The pathophysiology of delirium remains poorly understood. However, basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for the development of delirium. Dexmedetomidine is a α-2A adrenergic receptor agonist medication that patterns the activity of various arousal nuclei similar to sleep. A single night-time loading dose of dexmedetomidine promotes non-rapid eye movement sleep stages N2 and N3 sleep. This trial hypothesises dexmedetomidine-induced sleep as pre-emptive therapy for postoperative delirium. Methods and analysis The MINDDS (Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced Sleep) trial is a 370-patient block-randomised, placebocontrolled, double-blinded, single-site, parallel-arm superiority trial. Patients over 60 years old, undergoing cardiac surgery with planned cardiopulmonary bypass, will be randomised to receive a sleep-inducing dose of dexmedetomidine or placebo. The primary outcome is the incidence of delirium on postoperative day 1, assessed with the Confusion Assessment Method by staff blinded to the treatment assignment. To ensure that the study is appropriately powered for the primary outcome measure, patients will be recruited and randomised into the study until 370 patients receive the study intervention on postoperative day 0. Secondary outcomes will be evaluated by in-person assessments and medical record review for in-hospital end points, and by telephone interview for 30-day, 90-day and 180-day end points. All trial outcomes will be evaluated using an intention-to-treat analysis plan. Hypothesis testing will be performed using a two-sided significance level (type I error) of α=0.05. Sensitivity analyses using the actual treatment received will be performed and compared with the intention-to-treat analysis results. Additional sensitivity analyses will assess the potential impact of missing data due to loss of followup. Ethics and dissemination The Partners Human Research Committee approved the MINDDS trial. Recruitment began in March 2017. Dissemination plans include presentations at scientific conferences, scientific publications and popular media. [ABSTRACT FROM AUTHOR]

This paper seeks to provide new empirical evidence that demonstrates the importance of digital technologies in promoting economic growth, drawing on the literature on advances in growth and leveraging a broader and more robust country-level panel dataset. In particular, this paper estimates the long-run economic impact of digital technologies using mobile phone penetration and internet usage as broad indicators. The empirical results suggest that, between 2004 and 2014, the diffusion of digital technologies significantly improved economic output in Australia and abroad, contributing to steady-state gross domestic product per capita growth of approximately 5.8 per cent on average. These findings could serve as the starting-point for predictions about the likely impact of future technologies, providing a better understanding for policy-makers in prioritising initiatives that will continue to lift living standards in the coming years. [ABSTRACT FROM AUTHOR]

Tracheal intubation and ventilatory support are among the important treatments in patients infected with COVID-19 with acute respiratory distress syndrome (ARDS) and severe hypoxia. The intubating team often uses video-assisted intubation equipment to ensure a safe and successful tracheal intubation. In this case report, we demonstrate for the first time, the use of the Shikani video-assisted intubating stylet and the Shikani intubating technique as a safe, speedy, and effective way to intubate a critically ill and highly contagious COVID-19 patient. In addition to the conventional consensus guidelines that are currently available for good practice (such as the proper use of personal protection equipment, etc.), we demonstrated that using the Shikani video-assisted intubating stylet is a reliable and proficient technique that is easy to learn while minimizing the risk of COVID-19 exposure of the airway personnel. [ABSTRACT FROM AUTHOR]

• Ketamine is an anesthetic drug with dissociative properties. • Ketamine induces highly structured oscillations that may be used to monitor drug-induced altered arousal. • Surface electroencephalogram oscillations are unlikely to underly ketamine-induced dissociation. Ketamine is an anesthetic drug associated with dissociation. Decreased electroencephalogram alpha (8–13 Hz) and low-beta (13–20 Hz) oscillation power have been associated with ketamine-induced dissociation. We aimed to characterize surface electroencephalogram signatures that may serve as biomarkers for dissociation. We analyzed data from a single-site, open-label, high-density surface electroencephalogram study of ketamine anesthesia (2 mg/kg, n = 15). We assessed dissociation longitudinally using the Clinician Administered Dissociation States Scale (CADSS) and administered midazolam to attenuate dissociation and enable causal inference. We analyzed electroencephalogram power and global coherence with multitaper spectral methods. Mixed effects models were used to assess whether power and global coherence signatures of ketamine could be developed into dissociation-specific biomarkers. Compared to baseline, ketamine unresponsiveness was associated with increased frontal power between 0.5 to 9.3 Hz, 12.2 to 16.6 Hz, and 24.4 to 50 Hz. As subjects transitioned into a responsive but dissociated state (mean CADSS ± SD, 22.1 ± 17), there was a decrease in power between 0.5 to 10.3 Hz and 11.7 to 50 Hz. Midazolam reduced dissociation scores (14.3 ± 11.6), decreased power between 4.4 to 11.7 Hz and increased power between 14.2 to 50 Hz. Our mixed-effects model demonstrated a quadratic relationship between time and CADSS scores. When models (frontal power, occipital power, global coherence) were reanalyzed with midazolam and electroencephalogram features as covariates, only midazolam was retained. Ketamine is associated with structured electroencephalogram power and global coherence signatures that may enable principled anesthetic state but not dissociation monitoring. A neurophysiological biomarker for dissociation may lead to a better understanding of neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

Background: Type A aortic dissection presents challenges with postoperative cerebral complications, and this study evaluates the predictive value of quantitative electroencephalography for perioperative brain function prognosis., Methods and Results: Amplitude-integrated electroencephalography (aEEG) processes raw signals through filtering, amplitude integration, and time compression, displaying the data in a semilogarithmic format. Using this method, postoperative relative band power (post-RBP) α% and dynamic aEEG (ΔaEEG) grade were significantly associated with neurological dysfunction in univariate and multivariable analyses, with area under the receiver operating characteristic curve of 0.876 (95% CI, 0.825-0.926) for the combined model. Postoperative relative band power α% and ΔaEEG were significantly associated with adverse outcomes, with area under the receiver operating characteristic curve of 0.903 (95% CI, 0.835-0.971) for the combined model. Postoperative relative band power α% and ΔaEEG were significantly associated with transient neurological dysfunction and stroke, with areas under the receiver operating characteristic curve of 0.818 (95% CI, 0.760-0.876) and 0.868 (95% CI, 0.810-0.926) for transient neurological dysfunction, and 0.815 (95% CI, 0.743-0.886) and 0.831 (95% CI, 0.746-0.916) for stroke. Among 56 patients, the Alberta Stroke Program Early Computed Tomography score was superior to ΔaEEG in predicting neurological outcomes (area under the receiver operating characteristic curve of 0.872 versus 0.708 [95% CI, 0.633-0.783]; P <0.05)., Conclusions: Perioperative quantitative electroencephalography monitoring offers valuable insights into brain function changes in patients with type A aortic dissection. ∆aEEG grades can aid in early detection of adverse outcomes, while postoperative relative band power and ∆aEEG grades predict transient neurological dysfunction. Quantitative electroencephalography can assist cardiac surgeons in assessing brain function and improving outcomes in patients with type A aortic dissection., Registration: URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2200055980.

Competing Interests: Conflicts of Interest, Funding: Please see DISCLOSURES at the end of this article.

Background: The delirium-sparing effect of nighttime dexmedetomidine has not been studied after surgery. We hypothesised that a nighttime dose of dexmedetomidine would reduce the incidence of postoperative delirium as compared to placebo., Methods: This single-centre, parallel-arm, randomised, placebo-controlled superiority trial evaluated whether a short nighttime dose of intravenous dexmedetomidine (1 μg/kg over 40 min) would reduce the incidence of postoperative delirium in patients 60 years of age or older undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were randomised to receive dexmedetomidine or placebo in a 1:1 ratio. The primary outcome was delirium on postoperative day one. Secondary outcomes included delirium within three days of surgery, 30-, 90-, and 180-day abbreviated Montreal Cognitive Assessment scores, Patient Reported Outcome Measures Information System quality of life scores, and all-cause mortality. The study was registered as NCT02856594 on ClinicalTrials.gov on August 5, 2016, before the enrolment of any participants., Findings: Of 469 patients that underwent randomisation to placebo (n = 235) or dexmedetomidine (n = 234), 75 met a prespecified drop criterion before the study intervention. Thus, 394 participants (188 dexmedetomidine; 206 placebo) were analysed in the modified intention-to-treat cohort (median age 69 [IQR 64, 74] years; 73.1% male [n = 288]; 26·9% female [n = 106]). Postoperative delirium status on day one was missing for 30 (7.6%) patients. Among those in whom it could be assessed, the primary outcome occurred in 5 of 175 patients (2.9%) in the dexmedetomidine group and 16 of 189 patients (8.5%) in the placebo group (OR 0.32, 95% CI: 0.10-0.83; P = 0.029). A non-significant but higher proportion of participants experienced delirium within three days postoperatively in the placebo group (25/177; 14.1%) compared to the dexmedetomidine group (14/160; 8.8%; OR 0.58; 95% CI, 0.28-1.15). No significant differences between groups were observed in secondary outcomes or safety., Interpretation: Our findings suggested that in elderly cardiac surgery patients with a low baseline risk of postoperative delirium and extubated within 12 h of ICU admission, a short nighttime dose of dexmedetomidine decreased the incidence of delirium on postoperative day one. Although non-statistically significant, our findings also suggested a clinical meaningful difference in the three-day incidence of postoperative delirium., Funding: National Institute on Aging (R01AG053582)., Competing Interests: A.M. reports receiving funding from Roche Diagnostics and the University of Chicago for statistical consulting projects related to biomarkers in preeclampsia. T.T.H. reports receiving personal fees from Anesthesiology and Headache. L.B. receives salary support from K23 HL128882/NHLBI NIH. L.B. receives technologies and devices from iNO Therapeutics LLC, Praxair Inc., Masimo Corp., and grants from “Fast Grants for COVID-19 Research” at Mercatus Center of George Mason University and from iNO Therapeutics LLC. E.N.B. is a cofounder of PASCALL, a company developing closed-loop physiological control systems, and a cofounder of Neuradia, a company promoting the recovery of consciousness. E.N.B. and O.A. are listed as inventors on brain monitoring patents assigned to Massachusetts General Hospital. No other disclosures were reported., (© 2022 The Author(s).)

Introduction: Ketamine, an anesthetic adjunct, is routinely administered as part of a balanced general anesthetic technique. We recently showed that the acute analgesic and dissociation properties of ketamine are separable to suggest that distinct neural circuits underlie these states., Objective: We aimed to study whether this finding is robust to the substantial neural circuit alterations associated with general anesthesia., Methods: We conducted a single-site, open-label, randomized controlled, cross-over study of sevoflurane and sevoflurane-plus-ketamine (SK) general anesthesia in healthy subjects (n = 12). Before and after general anesthesia, we assessed precalibrated cuff pain intensity and nociceptive pain quality as well as dissociation using the Clinician-Administered Dissociative States Scale (CADSS). For statistical inference, we ran a variation of backward elimination repeated-measures analysis of covariance. Models with CADSS as a covariate term were used to assess whether dissociation mediated the effect of ketamine on pain intensity and quality., Results: Sevoflurane-plus-ketamine general anesthesia was associated with a significant ( P = 0.0002) pain intensity decline of 3 (SE, 0.44). There was an order effect for dissociation such that SK was associated with a significant ( P = 0.0043) CADSS increase of 17.8 (3.2) when the SK treatment came first. When the pain intensity model was reanalyzed with CADSS as an additional covariate, the effect of CADSS was not significant. These results were also conserved for pain quality., Conclusions: Our findings suggest that the analgesic and dissociation properties of ketamine remain separable despite general anesthesia. Thus, ketamine may be used as a probe to advance our knowledge of dissociation independent pain circuits., Competing Interests: O. Akeju has received speaker's honoraria from Masimo Corporation and is listed as an inventor on pending patents on EEG monitoring and oral dexmedetomidine assigned to Massachusetts General Hospital. The remaining authors have no conflicts of interest to declare. NIH NIA RO1AG053582 to O. Akeju; and, Innovation funds from the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital to O. Akeju; funds from División de Anestesiología, Escuela de Medicina, Pontificia Universidad Católica de Chile to J.C. Pedemonte.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The International Association for the Study of Pain.)