Where do ICU trainees really look? An eye-tracking analysis of gaze patterns during central venous catheter insertion.

BACKGROUND: There is limited knowledge about gaze patterns of intensive care unit (ICU) trainee doctors during the insertion of a central venous catheter (CVC). The primary objective of this study was to examine visual patterns exhibited by ICU trainee doctors during CVC insertion. Additionally, the study investigated whether differences in gaze patterns could be identified between more and less experienced trainee doctors. METHODS: In a real-life, prospective observational study conducted at the interdisciplinary ICU at the University Hospital Zurich, Switzerland, ICU trainee doctors underwent eye-tracking during CVC insertion in a real ICU patient. Using mixed-effects model analyses, the primary outcomes were dwell time, first fixation duration, revisits, fixation count, and average fixation time on different areas of interest (AOI). Secondary outcomes were above eye-tracking outcome measures stratified according to experience level of participants. RESULTS: Eighteen participants were included, of whom 10 were inexperienced and eight more experienced. Dwell time was highest for CVC preparation table (p = 0.02), jugular vein on ultrasound image (p < 0.001) and cervical puncture location (p < 0.001). Concerning experience, dwell time and revisits on jugular vein on ultrasound image (p = 0.02 and p = 0.04, respectively) and cervical puncture location (p = 0.004 and p = 0.01, respectively) were decreased in more experienced ICU trainees. CONCLUSIONS: Various AOIs have distinct significance for ICU trainee doctors during CVC insertion. Experienced participants exhibited different gaze behavior, requiring less attention for preparation and handling tasks, emphasizing the importance of hand-eye coordination.

Video Laryngoscopy vs Direct Laryngoscopy for Endotracheal Intubation in the Operating Room: A Cluster Randomized Clinical Trial.

Importance: Endotracheal tubes are typically inserted in the operating room using direct laryngoscopy. Video laryngoscopy has been reported to improve airway visualization; however, whether improved visualization reduces intubation attempts in surgical patients is unclear. Objective: To determine whether the number of intubation attempts per surgical procedure is lower when initial laryngoscopy is performed using video laryngoscopy or direct laryngoscopy. Design, Setting, and Participants: Cluster randomized multiple crossover clinical trial conducted at a single US academic hospital. Patients were adults aged 18 years or older having elective or emergent cardiac, thoracic, or vascular surgical procedures who required single-lumen endotracheal intubation for general anesthesia. Patients were enrolled from March 30, 2021, to December 31, 2022. Data analysis was based on intention to treat. Interventions: Two sets of 11 operating rooms were randomized on a 1-week basis to perform hyperangulated video laryngoscopy or direct laryngoscopy for the initial intubation attempt. Main Outcomes and Measures: The primary outcome was the number of operating room intubation attempts per surgical procedure. Secondary outcomes were intubation failure, defined as the responsible clinician switching to an alternative laryngoscopy device for any reason at any time, or by more than 3 intubation attempts, and a composite of airway and dental injuries. Results: Among 8429 surgical procedures in 7736 patients, the median patient age was 66 (IQR, 56-73) years, 35% (2950) were women, and 85% (7135) had elective surgical procedures. More than 1 intubation attempt was required in 77 of 4413 surgical procedures (1.7%) randomized to receive video laryngoscopy vs 306 of 4016 surgical procedures (7.6%) randomized to receive direct laryngoscopy, with an estimated proportional odds ratio for the number of intubation attempts of 0.20 (95% CI, 0.14-0.28; P < .001). Intubation failure occurred in 12 of 4413 surgical procedures (0.27%) using video laryngoscopy vs 161 of 4016 surgical procedures (4.0%) using direct laryngoscopy (relative risk, 0.06; 95% CI, 0.03-0.14; P < .001) with an unadjusted absolute risk difference of -3.7% (95% CI, -4.4% to -3.2%). Airway and dental injuries did not differ significantly between video laryngoscopy (41 injuries [0.93%]) vs direct laryngoscopy (42 injuries [1.1%]). Conclusion and Relevance: In this study among adults having surgical procedures who required single-lumen endotracheal intubation for general anesthesia, hyperangulated video laryngoscopy decreased the number of attempts needed to achieve endotracheal intubation compared with direct laryngoscopy at a single academic medical center in the US. Results suggest that video laryngoscopy may be a preferable approach for intubating patients undergoing surgical procedures. Trial Registration: ClinicalTrials.gov Identifier: NCT04701762.

A neural circuit for vocal production responds to viscerosensory input in the songbird.

Motor performance is monitored continuously by specialized brain circuits and used adaptively to modify behavior on a moment-to-moment basis and over longer time periods. During vocal behaviors, such as singing in songbirds, internal evaluation of motor performance relies on sensory input from the auditory and vocal-respiratory systems. Sensory input from the auditory system to the motor system, often referred to as auditory feedback, has been well studied in singing zebra finches (Taeniopygia guttata), but little is known about how and where nonauditory sensory feedback is evaluated. Here we show that brief perturbations in air sac pressure cause short-latency neural responses in the higher-order song control nucleus HVC (used as proper name), an area necessary for song learning and song production. Air sacs were briefly pressurized through a cannula in anesthetized or sedated adult male zebra finches, and neural responses were recorded in both nucleus parambigualis (PAm), a brainstem inspiratory center, and HVC, a cortical premotor nucleus. These findings show that song control nuclei in the avian song system are sensitive to perturbations directly targeted to vocal-respiratory, or viscerosensory, afferents and support a role for multimodal sensory feedback integration in modifying and controlling vocal control circuits.NEW & NOTEWORTHY This study presents the first evidence of sensory input from the vocal-respiratory periphery directly activating neurons in a motor circuit for vocal production in songbirds. It was previously thought that this circuit relies exclusively on sensory input from the auditory system, but we provide groundbreaking evidence for nonauditory sensory input reaching the higher-order premotor nucleus HVC, expanding our understanding of what sensory feedback may be available for vocal control.

Postoperative oxygenation assessed by SpO2/FiO2 ratio and respiratory complications after reversal of neuromuscular block with Sugammadex or neostigmine: A retrospective cohort study.

STUDY OBJECTIVE: Residual neuromuscular block may lead to postoperative muscle weakness, inadequate oxygenation, and other pulmonary complications. Sugammadex may provide more rapid and effective restoration of neuromuscular function than neostigmine. We therefore tested the primary hypothesis that noncardiac surgical patients given sugammadex oxygenate better during initial recovery than those given neostigmine. Secondarily, we tested the hypothesis that patients given sugammadex have fewer pulmonary complications during hospitalization. DESIGN: Retrospective cohort analysis. SETTING: Postoperative recovery area of a tertiary care hospital. PATIENTS: Adults who had non-cardiothoracic surgery and were given either neostigmine or sugammadex. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was the lowest SpO2/FiO2 ratio in the post-anesthesia care unit. The secondary outcome was a composite of pulmonary complications. MAIN RESULTS: Among 71,457 cases, 10,708 (15%) were given sugammadex and 60,749 (85%) received neostigmine. After propensity weighting, the mean minimum SpO2/FiO2 ratio was 301 ± 77 (SD) in patients given sugammadex and 303 ± 71 in those given neostigmine, yielding an estimated difference in means of -3.5 (95% confidence interval: -5.3, -1.7; P = 0.0002). 4.4% of patients given sugammadex and 3.6% of patients given neostigmine had postoperative pulmonary complications (P = 0.0005, number-needed-to-be-exposed =136; 95% CI: 83, 330), with the main contributing components being new bronchospasm or exacerbation of obstructive pulmonary disease. CONCLUSIONS: Postoperative minimum SpO2/FiO2 ratio during PACU admission was similar after reversal of neuromuscular block by sugammadex and neostigmine. Reversal with sugammadex was associated with more pulmonary complications, but most were minor and of little consequence.

There is no evidence that carbon dioxide-enriched oxygen before apnea affects the time to arterial desaturation, but it might improve cerebral oxygenation in anesthetized obese patients: a single-blinded randomized crossover trial.

PURPOSE: Carbon dioxide (CO2) increases cerebral perfusion. The effect of CO2 on apnea tolerance, such as after anesthesia induction, is unknown. This study aimed to assess if cerebral apnea tolerance can be improved in obese patients under general anesthesia when comparing O2/Air (95%O2) to O2/CO2 (95%O2/5%CO2). METHODS: In this single-center, single-blinded, randomized crossover trial, 30 patients 18-65 years, with body mass index > 35 kg/m2, requiring general anesthesia for bariatric surgery, underwent two apneas that were preceded by ventilation with either O2/Air or O2/CO2 in random order. After anesthesia induction, intubation, and ventilation with O2/Air or O2/CO2 for 10 min, apnea was performed until the cerebral tissue oxygenation index (TOI) dropped by a relative 20% from baseline (primary endpoint) or oxygen saturation (SpO2) reached 80% (safety abortion criterion). The intervention was then repeated with the second substance. RESULTS: The safety criterion was reached in all patients before cerebral TOI decreased by 20%. The time until SpO2 dropped to 80% was similar in the two groups (+ 6 s with O2/CO2, 95%CI -7 to 19 s, p = 0.37). Cerebral TOI and PaO2 were higher after O2/CO2 (+ 1.5%; 95%CI: from 0.3 to 2.6; p = 0.02 and + 0.6 kPa; 95%CI: 0.1 to 1.1; p = 0.02). CONCLUSION: O2/CO2 improves cerebral TOI and PaO2 in anesthetized bariatric patients. Better apnea tolerance could not be confirmed.

Postoperative Risk of Transfusion After Reversal of Residual Neuromuscular Block With Sugammadex Versus Neostigmine: A Retrospective Cohort Study.

BACKGROUND: Sugammadex and neostigmine are routinely used to reverse residual neuromuscular blocks at the end of surgery. Sugammadex has been linked with prolongation of laboratory coagulation markers, but clinical relevance on postoperative blood loss and transfusions remains unclear. METHODS: In this retrospective, single-center, cohort study, we analyzed medical records of adult patients having noncardiac surgery who were given sugammadex or neostigmine from May 2016 to December 2020. Our primary outcome was the incidence of any postoperative transfusion of red blood cells, and/or fresh-frozen plasma, and/or platelets. Secondary outcomes were duration of hospitalization, need for resurgery, and postoperative intensive care unit (ICU) admission. After propensity score weighting, the odds ratio (OR) for postoperative transfusion was assessed in both groups (sugammadex versus neostigmine) using a generalized estimation equation to count within-subject correlation weighted by the inverse propensity score. RESULTS: Out of 39,325 eligible surgeries, 33,903 surgeries in 29,062 patients were included in the analysis; with 4581 patients receiving sugammadex and 29,322 patients receiving neostigmine. The raw incidence of postoperative transfusion was 7.40% in sugammadex and 7.45% in the neostigmine group. After weighting by propensity score, the incidence of postoperative transfusion was 8.01% in the sugammadex and 7.38% in the neostigmine group (OR, 1.11 [95% confidence interval [CI], 0.97-1.26; P = .118]). There was no difference in duration of hospitalization and need for resurgery, but odds of postoperative ICU admission were significantly higher for patients receiving sugammadex than those receiving neostigmine (OR, 1.33 [98.33% CI, 1.17-1.52; P < .0001]). Our a priori planned analysis of coagulation laboratory parameters could not be completed because of a high amount of missing laboratory data. CONCLUSIONS: There is no statistically significant nor clinically important difference in the risk of postoperative transfusion in patients receiving sugammadex or neostigmine.

Viridiplantae-specific GLXI and GLXII isoforms co-evolved and detoxify glucosone in planta.

Reactive carbonyl species (RCS) such as methylglyoxal (MGO) and glyoxal (GO) are highly reactive, unwanted side-products of cellular metabolism maintained at harmless intracellular levels by specific scavenging mechanisms.MGO and GO are metabolized through the glyoxalase (GLX) system, which consists of two enzymes acting in sequence, GLXI and GLXII. While plant genomes encode a number of different GLX isoforms, their specific functions and how they arose during evolution are unclear. Here, we used Arabidopsis (Arabidopsis thaliana) as a model species to investigate the evolutionary history of GLXI and GLXII in plants and whether the GLX system can protect plant cells from the toxicity of RCS other than MGO and GO. We show that plants possess two GLX systems of different evolutionary origins and with distinct structural and functional properties. The first system is shared by all eukaryotes, scavenges MGO and GO, especially during seedling establishment, and features Zn2+-type GLXI proteins with a metal cofactor preference that were present in the last eukaryotic common ancestor. GLXI and GLXII of the second system, featuring Ni2+-type GLXI, were acquired by the last common ancestor of Viridiplantae through horizontal gene transfer from proteobacteria and can together metabolize keto-D-glucose (KDG, glucosone), a glucose-derived RCS, to D-gluconate. When plants displaying loss-of-function of a Viridiplantae-specific GLXI were grown in KDG, D-gluconate levels were reduced to 10%-15% of those in the wild type, while KDG levels showed an increase of 48%-67%. In contrast to bacterial GLXI homologs, which are active as dimers, plant Ni2+-type GLXI proteins contain a domain duplication, are active as monomers, and have a modified second active site. The acquisition and neofunctionalization of a structurally, biochemically, and functionally distinct GLX system indicates that Viridiplantae are under strong selection to detoxify diverse RCS.

Association between body mass index and difficult intubation with a double lumen tube: A retrospective cohort study.

STUDY OBJECTIVE: Obesity, defined by the World Health Organization as body mass index (BMI) ≥ 30.0 kg/m2, is associated with adverse outcomes and challenges during surgery. Difficulties during endotracheal intubation, occur in 3-8% of procedures and are among the principal causes of anesthetic-related morbidity and mortality. Endotracheal intubation can be challenging in obese patients due to an array of anatomic and physiologic factors. Double lumen tubes (DLTs), the most commonly used airway technique to facilitate anatomic isolation of the lungs for one lung ventilation. However, DLTs can be difficult to properly position and are also more likely to cause airway injuries and bleeding when compared to conventional single lumen tubes. We investigated the association between BMI and difficult tracheal DLT intubation. DESIGN: Retrospective cohort study. SETTING: Operating room. PATIENTS: We analyzed electronic records of adults having cardiac and thoracic surgery requiring general anesthesia and endotracheal intubation with DLT at the Cleveland Clinic between 2008 and 2021. MEASUREMENTS: BMI, preoperative airway abnormalities and difficult intubation, defined as more than one intubation attempt, was assessed using multivariable logistic regression. MAIN RESULTS: Among 8641 analyzed anesthetics requiring DLT, 1459 (17%) were difficult intubations. After adjusting for confounders, each 5 kg/m2 increase in BMI was associated with a marginal increase of difficult intubation, odds ratio (OR) 1.06 (95% Confidence Interval [CI]: 1.002, 1.11; P = 0.040). Difficult intubation was not associated with airway abnormalities, estimated OR 0.85 (95% CI: 0.62, 1.17; P = 0.321). There was no interaction between known airway abnormalities and BMI (P = 0.894). CONCLUSIONS: Difficult intubations with DLT remain common, but BMI is a weak predictor thereof. For example, an increase in BMI from 20 to 40 kg/m2 corresponds to an increase in average absolute risk for difficult intubation from 16 to 19%, which probably is not clinically meaningful.

Transesophageal Echocardiography-Guided Transseptal Left Atrial Access to Improve Safety in Patients Undergoing Pulmonary Vein Isolation.

BACKGROUND: Endovascular pulmonary vein isolation (PVI) has become an important strategy for rhythm control in patients with symptomatic atrial fibrillation (AF). Transseptal access is a critical step of this procedure and can result in potentially life-threatening complications. This retrospective study evaluates the safety of standardized, transesophageal echocardiography (TEE)-guided transseptal access to the left atrium in consecutive patients who underwent PVI. METHODS: After the implementation of a standardized, TEE-guided procedure for transseptal access, the data of 404 consecutive PVI procedures using radiofrequency ablation and 3D-mapping were prospectively collected over 5 years. TEE-guided transseptal punctures were performed on 375 patients undergoing one to three PVIs. The patient cohort was retrospectively analyzed for major and minor complications, fluoroscopy time, fluoroscopy dose and ablation outcomes. RESULTS: No single complication related to transseptal access occurred, affirming the safety of the TEE-guided approach. Fluoroscopy time and fluoroscopy dose decreased significantly after 152 procedures. PVI-related minor complications occurred in 11 procedures (2.6%) and included 10 vascular-access-related complications (2.4%) and 1 TEE-related esophageal hematoma (0.2%), which healed spontaneously. CONCLUSION: Our single-center study shows that TEE guidance may allow safe transseptal access to the left atrium in patients undergoing PVI.

Proposing a neural framework for the evolution of elaborate courtship displays.

In many vertebrates, courtship occurs through the performance of elaborate behavioral displays that are as spectacular as they are complex. The question of how sexual selection acts upon these animals' neuromuscular systems to transform a repertoire of pre-existing movements into such remarkable (if not unusual) display routines has received relatively little research attention. This is a surprising gap in knowledge, given that unraveling this extraordinary process is central to understanding the evolution of behavioral diversity and its neural control. In many vertebrates, courtship displays often push the limits of neuromuscular performance, and often in a ritualized manner. These displays can range from songs that require rapid switching between two independently controlled 'voice boxes' to precisely choreographed acrobatics. Here, we propose a framework for thinking about how the brain might not only control these displays, but also shape their evolution. Our framework focuses specifically on a major midbrain area, which we view as a likely important node in the orchestration of the complex neural control of behavior used in the courtship process. This area is the periaqueductal grey (PAG), as studies suggest that it is both necessary and sufficient for the production of many instinctive survival behaviors, including courtship vocalizations. Thus, we speculate about why the PAG, as well as its key inputs, might serve as targets of sexual selection for display behavior. In doing so, we attempt to combine core ideas about the neural control of behavior with principles of display evolution. Our intent is to spur research in this area and bring together neurobiologists and behavioral ecologists to more fully understand the role that the brain might play in behavioral innovation and diversification.