Intra-operative electroencephalogram frontal alpha-band spectral analysis and postoperative delirium in cardiac surgery: A prospective cohort study.

BACKGROUND: Postoperative delirium (POD) remains a frequent complication after cardiac surgery, with pre-operative cognitive status being one of the main predisposing factors. However, performing complete pre-operative neuropsychological testing is challenging. The magnitude of frontal electroencephalographic (EEG) α oscillations during general anaesthesia has been related to pre-operative cognition and could constitute a functional marker for brain vulnerability. OBJECTIVE: We hypothesised that features of intra-operative α-band activity could predict the occurrence of POD. DESIGN: Single-centre prospective observational study. SETTING: University hospital, from 15 May 2019 to 15 December 2021. PATIENTS: Adult patients undergoing elective cardiac surgery. MAIN OUTCOME MEASURES: Pre-operative cognitive status was assessed by neuropsychological tests and scored as a global z score. A 5-min EEG recording was obtained 30 min after induction of anaesthesia. Anaesthesia was maintained with sevoflurane. Power and peak frequency in the α-band were extracted from the frequency spectra. POD was assessed using the Confusion Assessment Method for Intensive Care Unit, the Confusion Assessment Method and a chart review. RESULTS: Sixty-five (29.5%) of 220 patients developed POD. Delirious patients were significantly older with median [IQR] ages of 74 [64 to 79] years vs. 67 [59 to 74] years; P  < 0.001) and had lower pre-operative cognitive z scores (-0.52 ±â€Š1.14 vs. 0.21 ±â€Š0.84; P  < 0.001). Mean α power (-14.03 ±â€Š4.61 dB vs. -11.59 ±â€Š3.37 dB; P  < 0.001) and maximum α power (-11.36 ±â€Š5.28 dB vs. -8.85 ±â€Š3.90 dB; P  < 0.001) were significantly lower in delirious patients. Intra-operative mean α power was significantly associated with the probability of developing POD (adjusted odds ratio, 0.88; 95% confidence interval (CI), 0.81 to 0.96; P  = 0.007), independently of age and only whenever cognitive status was not considered. CONCLUSION: A lower intra-operative frontal α-band power is associated with a higher incidence of POD after cardiac surgery. Intra-operative measures of α power could constitute a means of identifying patients at risk of this complication. TRIAL REGISTRATION: NCT03706989.

Propofol plus low-dose dexmedetomidine infusion and postoperative delirium in older patients undergoing cardiac surgery.

BACKGROUND: Postoperative delirium (POD) is a frequent complication in older patients. Dexmedetomidine might be effective in decreasing the incidence of POD. We hypothesised that adding low-dose rate dexmedetomidine infusion to a propofol sedation regimen would have fewer side-effects and would counteract the possible delirium producing properties of propofol, resulting in a lower risk of POD than propofol with placebo. METHODS: In this double-blind placebo-controlled trial, patients ≥60 yr old undergoing on-pump cardiac surgery were randomised 1:1 to the following postoperative sedative regimens: a propofol infusion and dexmedetomidine (0.4 µg kg-1 h-1) or a propofol infusion and saline 0.9% (placebo group). The study drug was started at chest closure and continued for 10 h. The primary endpoint was in-hospital POD, assessed using the Confusion Assessment Method and chart review method. RESULTS: POD over the course of hospital stay occurred in 31/177 (18%) and 33/172 (19%) patients in the dexmedetomidine and placebo arm, respectively (P=0.687; odds ratio=0.89; 95% confidence interval, 0.52-1.54). The incidence of POD in the intensive care alone, or on the ward alone, was also not significantly different between the groups. Subjects in the dexmedetomidine group spent less median time in a delirious state (P=0.026). Median administered postoperative norepinephrine was significantly higher in the dexmedetomidine group (P<0.001). One patient in the dexmedetomidine group and 10 patients in the placebo group died in the hospital. CONCLUSIONS: Adding low-dose rate dexmedetomidine to a sedative regimen based on propofol did not result in a different risk of in-hospital delirium in older patients undergoing cardiac surgery. With a suggestion of both harm and benefit in secondary outcomes, supplementing postoperative propofol with dexmedetomidine cannot be recommended based on this study. CLINICAL TRIAL REGISTRATION: NCT03388541.

Robotic-Assisted Lobectomy Favors Early Lung Recovery versus Limited Thoracotomy.

BACKGROUND: Postoperative pulmonary recovery after lobectomy has showed early benefits for the video-assisted thoracoscopic surgery and sparing open techniques over nonsparing techniques. Robotic-assisted procedures offer benefits in term of clinical outcomes, but their advantages on pulmonary recovery and quality of life have not yet been distinctly prospectively studied. METHODS: Eighty-six patients undergoing lobectomy over a period of 29 months were prospectively studied for their pulmonary function recovery and pain score level during the in-hospital stay and at 1, 2, and 6 months. Quality of life was evaluated at 2 and 6 months. Forty-five patients were operated by posterolateral limited thoracotomy and 41 patients by robotic approach. The postoperative analgesia protocol differed for the two groups, being lighter for the robotic group. RESULTS: The pulmonary tests were not significantly different during the in-hospital stay. At 1 month, the forced expiratory volume in 1 second, forced vital capacity, vital capacity, and maximal expiratory pressure were significantly better for the robotic group (p = 0.05, 0.04, 0.05, and 0.02, respectively). There was no significant difference left at 2 and 6 months. Pain intensity was equivalent during the in-hospital stay but was significantly lower for the robotic group at 1 month (p = 0.02). At 2 and 6 months, pain and quality of life were comparable. CONCLUSION: Robotic technique can offer similar pulmonary and pain recovery during the in-hospital stay with a lighter analgesia protocol. It clearly favors the early term recovery compared with the open limited technique. The objective and subjective functional recovery becomes equivalent at 2 and 6 months.

Combined Use of Rotational Thromboelastometry (Rotem) and Platelet Impedance Aggregometry (Multiplate Analyzer) in Cyanotic and Acyanotic Infants and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass: Subgroup Analysis of a Randomized Clinical Trial.

OBJECTIVES: Few studies have investigated the Multiplate platelet function analyzer in pediatrics. The authors evaluated Multiplate combined with Rotem in terms of guiding platelet transfusion after pediatric cardiac surgery with cardiopulmonary bypass (CPB). The authors further compared coagulation parameters between cyanotic and acyanotic patients. DESIGN: Subgroup analysis of a randomized clinical trial. SETTING: Tertiary hospital. PARTICIPANTS: Patients weighing between seven and 15 kg. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Rotem and Multiplate tests were performed (1) after anesthesia induction, (2) upon CPB separation, and (3) upon intensive care unit arrival. Among a total of 59 subjects, 9 patients required platelet transfusion. In multivariate linear regression, analysis EXTEM maximum clot firmness upon CPB separation was associated with the volume of transfused platelets (regression coefficient = -0.348 [95% confidence interval -1.006 to -0.028]; p = 0.039). No such association was found for the Multiplate test. Acyanotic and cyanotic heart disease were present in 32 and 27 children, respectively. There were no significant differences between these two groups in terms of platelet count and function. Postoperative blood loss was significantly higher in the cyanotic group compared with the acyanotic arm (p = 0.015; difference [95% confidence interval -2.40 {-4.20 to -0.60}]). There were no differences between groups regarding transfusion of allogeneic blood products. CONCLUSIONS: This study showed that Rotem, but not Multiplate results, were associated with platelet transfusion in pediatric cardiac surgery with no intake of platelet inhibitors. The usefulness of combining these tests in platelet transfusion decision-making needs to be evaluated in larger populations.

Assessing Gender-Affirming Chest Surgery Outcomes: Does Gender Identity Alter Gaze?

BACKGROUND: Outcomes of gender-affirming chest surgery can be variable. Placement of nipple-areolar complexes and orientation of scars can drastically affect the aesthetic outcomes of these procedures, as may observer gender identity. Here, we compared attention and perception of outcomes following gender-affirming chest surgery between laypersons, based on gender identity. METHODS: Transgender and cisgender participants were enrolled and shown images of surgery naïve chests and postoperative masculinized and feminized chests, blinded to the gender identity of the photographed subject. Gaze data were captured using the Tobii X2 60 eye-tracking device. Participants scored the perceived gender and aesthetic appearance of each image. RESULTS: Eighteen cisgender and 14 transgender participants were enrolled. When viewing male chests, transgender participants spent significantly longer fixated on the nipples (naïve: 802 vs. 395 ms; p = 0.02, masculinized: 940 vs. 692 ms, p = 0.002). For masculinized chests, cisgender participants spent significantly longer fixated on the inframammary scar (483 vs. 391 ms; p = 0.04). On images of feminized chests, transgender participants spent longer viewing the nipples when compared to cisgender participants (1017 vs. 847 ms; p = 0.04). Cisgender viewers spent longer fixating on the postoperative scar on feminized chests (113 vs. 59 ms; p = 0.02) and also viewed feminized chests as significantly more masculine and masculinized chests as more feminine, when compared to transgender participants (p < 0.05). CONCLUSIONS: This is the first study to use eye-tracking to assess how laypersons assess chests for gender determination. The findings suggest that observer gender identity has an effect on areas of focus and gender perception of chests that underwent gender-affirmation surgery. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

Fresh Frozen Plasma versus Crystalloid Priming of Cardiopulmonary Bypass Circuit in Pediatric Surgery: A Randomized Clinical Trial.

BACKGROUND: In congenital cardiac surgery, priming cardiopulmonary bypass (CPB) with fresh frozen plasma (FFP) is performed to prevent coagulation abnormalities. The hypothesis was that CPB priming with crystalloids would be different compared with FFP in terms of bleeding and/or need for blood product transfusion. METHODS: In this parallel-arm double-blinded study, patients weighing between 7 and 15 kg were randomly assigned to a CPB priming with 15 ml · kg PlasmaLyte or 15 ml · kg FFP in addition to a predefined amount of packed red blood cells used in all patients. The decision to transfuse was clinical and guided by point-of-care tests. The primary endpoints included postoperative bleeding tracked by chest tubes, number of patients transfused with any additional blood products, and the total number of additional blood products administered intra- and postoperatively. The postoperative period included the first 6 h after intensive care unit arrival. RESULTS: Respectively, 30 and 29 patients in the FFP and in the crystalloid group were analyzed in an intention-to-treat basis. Median postoperative blood loss was 7.1 ml · kg (5.1, 9.4) in the FFP group and 5.7 ml · kg (3.8, 8.5) in the crystalloid group (P = 0.219); difference (95% CI): 1.2 (-0.7 to 3.2). The proportion of patients additionally transfused was 26.7% (8 of 30) and 37.9% (11 of 29) in the FFP and the crystalloid groups, respectively (P = 0.355; odds ratio [95% CI], 1.7 [0.6 to 5.1]). The median number of any blood products transfused in addition to priming was 0 (0, 1) and 0 (0, 2) in the FFP and crystalloid groups, respectively (P = 0.254; difference [95% CI], 0 [0 to 0]). There were no study-related adverse events. CONCLUSIONS: The results demonstrate that in infants and children, priming CPB with crystalloids does not result in a different risk of postoperative bleeding and need for transfusion of allogeneic blood products.

Predicting postoperative delirium and postoperative cognitive decline with combined intraoperative electroencephalogram monitoring and cerebral near-infrared spectroscopy in patients undergoing cardiac interventions.

Studies have associated electroencephalogram (EEG) suppression with postoperative delirium (POD) and postoperative cognitive decline (POCD). Otherwise, improving cerebral tissue oxygen saturation (rScO2) seems beneficial. No study has evaluated the impact of EEG suppression and decreased rScO2 on the incidence of POD and POCD when the intraoperative management of patients is performed with a depth-of-anesthesia (DOA) monitor and a cerebral oximetry. In this prospective study patients undergoing cardiac interventions were monitored with the NeuroSENSE® DOA monitor and bilateral cerebral oximetry. An algorithm was used to optimize cerebral oxygenation. EEG suppression was presented as total area under the curve (AUC) of suppression ratio (SR) > 0 s (AUCEEGSR>0s). Cerebral desaturation was defined as AUC of 25% drop of oximetry values as compared to baseline. POD was evaluated by the chart review method. POCD was defined as a Z-score ≤ 2 based on Mini Mental State Examination at baseline and day 5 or if the patient reported any cognitive decline at 3 and at 6 months postoperatively. Among the 1616 patients, 1513 underwent normothermic surgery and were further analyzed. POD and POCD were respectively evaluated in 1504 and 1350 patients of whom 303 (20%) and 270 (20%) were respectively diagnosed positive. Having experienced high magnitudes of EEG suppression (fourth quartile of AUCEEGSR>0s) was significantly associated with POD (OR = 2.247; 95% CI = 1.414-3.571; P = 0.001). Low rScO2 at the end of surgery was statistically associated with POCD (OR = 0.981; 95% CI = 0.965-0.997; P = 0.018). The results of our study show that the degree of intraoperative EEG suppression on one hand, and low rScO2 at the end of procedure on the other hand, are associated with respectively POD and POCD in patients undergoing cardiac interventions.

Pain, Quality of Life, and Clinical Outcomes after Robotic Lobectomy.

Background To evaluate pulmonary function, pain, and quality of life at midterm after robotic lobectomy performed in a single institution. Methods Sixty-five consecutive patients underwent robotic thoracic surgery over 32 months using a complete four-arm portal technique. Sixty-one patients underwent lobectomies predominantly for stage I non-small cell lung cancer. Pulmonary function tests were repeated at midterm follow-up. Pain and quality of life were evaluated during the follow-up on a subgroup of 39 patients, excluding the learning period. Results At a mean of 7-month follow-up, there was no significant difference in preoperative and midterm postoperative pulmonary function. A total of 62.5% of the patients reported a variable intensity of discomfort or pain at the surgical site, with a mean pain intensity score of 2.1 ± 1.4. Mean pain interference score were weak (1.8 ± 1.9), with patients with moderate pain reporting significantly higher pain interference scores than those with mild pain (p = 0.0025). Only one patient suffered from neuropathic-like pain. Quality of life was globally favorable and related to the pain level, with a significant interference on the physical component. Conclusion Robotic lobectomy does not appear to have an impact on midterm pulmonary function. Persistent postoperative pain is mild, nonneuropathic-like, with weak interference on daily activities. Quality of life is satisfactory but related to the pain level.

A novel thermal compression device for perioperative warming: a randomized trial for feasibility and efficacy.

BACKGROUND: Inadvertent perioperative hypothermia (IPH) leads to surgical complications and increases length of stay. IPH rates are high with the current standard of care, forced air warming (FAW). Our hypothesis is that a prototype thermal compression device that heats the popliteal fossa and soles of the feet, with lower leg compression, increases perioperative temperatures and reduces IPH compared to the current standard of care. METHODS: Thirty six female breast surgery patients, at a tertiary academic hospital, were randomized to the device or intraoperative FAW (stage I) with a further 18 patients randomized to the device with a single heating area only (stage II, popliteal fossa or sole of the feet). Stage I: 37 patients recruited (final 36). Stage II: 18 patients recruited (final 18). INCLUSION CRITERIA: general anesthesia with esophageal monitoring for over 30 min, legs available and able to fit the device and no contraindications to leg heating or compression. The intervention was: Stage I: Investigational prototype thermal compression device (full device group) or intraoperative FAW. Stage II: Device with only a single heating location. Primary outcomes were perioperative temperatures and incidence of IPH. Secondary outcomes were local skin temperature, general and thermal comfort scores and presence of perioperative complications, including blood loss. RESULTS: Mean temperatures in the full device group were significantly higher than the FAW group in the pre-operative (36.7 vs 36.4 °C, p < 0.001), early intraoperative (36.3 vs 35.9 °C, p < 0.001), intraoperative (36.6 vs 36.2 °C, p < 0.001) and postoperative periods (36.8 vs 36.5 °C, p < 0.001). The incidence of IPH in the device group was also significantly lower (16.7% vs 72.0%, p = 0.001). Thermal comfort scores were significantly higher in the full device group and hypothermia associated wound complications were higher in the FAW group. CONCLUSIONS: The thermal compression device is feasible and has efficacy over the FAW. Further studies are recommended to investigate clinically significant outcomes. TRIAL REGISTRATION: clinicaltrials.gov ( NCT02155400 ).

Molecular origin of a loading-induced black layer in the deep region of articular cartilage at the magic angle.

PURPOSE: To investigate the molecular origin of an unusual low-intensity layer in the deep region of articular cartilage as seen in magnetic resonance imaging (MRI) when the tissue is imaged under compression and oriented at the magic angle. MATERIALS AND METHODS: Microscopic MRI (µMRI) T2 and T1 ρ experiments were carried out on 18 specimens, both native and degraded (treated with trypsin). The glycosaminoglycan (GAG) concentrations in the specimens were quantified by both sodium ICP-OES and µMRI Gd(DTPA)(2-) -contrast methods. The mechanical modulus of the specimens was also measured. RESULTS: Native tissue shows no load-induced layer, while the trypsin-degraded tissue shows clearly the low-intensity line at the deep part of tissue. The GAG reductions were confirmed by the sodium ICP-OES (from 81.7 ± 5.4 mg/mL to 9.2 ± 3.4 mg/mL), MRI GAG quantification (from 72.4 ± 6.7 mg/mL to 11.2 ± 2.9 mg/mL). The modulus reduction was confirmed by biomechanics (from 4.3 ± 0.7 MPa to 0.3 ± 0.1 MPa). CONCLUSION: Both T2 and T1 ρ profiles in native and degraded cartilage show strongly strain-, depth-, and angle-dependence using high-resolution MRI. The GAG reduction is responsible for the visualization of a low-intensity layer in deep cartilage when it is loaded and oriented at 55°.

Effects of cryopreservation on the depth-dependent elastic modulus in articular cartilage and implications for osteochondral grafting.

Cryopreservation of articular cartilage is often used in storage of experimental samples and osteochondral grafts, but the depth-dependence and concentration of glycosaminoglycan (GAG) are significantly altered when cryogenically stored without a cryoprotectant, which will reduce cartilage stiffness and affect osteochondral graft function and long-term viability. This study investigates our ability to detect changes due to cryopreservation in the depth-dependent elastic modulus of osteochondral samples. Using a direct-visualization method requiring minimal histological alterations, unconfined stepwise stress relaxation tests were performed on four fresh (never frozen) and three cryopreserved (-20 °C) canine humeral head osteochondral slices 125 ± 5 µm thick. Applied force was measured and tissue images were taken at the end of each relaxation phase using a 4× objective. Intratissue displacements were calculated by tracking chondrocytes through consecutive images for various intratissue depths. The depth-dependent elastic modulus was compared between fresh and cryopreserved tissue for same-depth ranges using analysis of variance (ANOVA) with Tukey post-test with a 95% confidence interval. Cryopreservation was found to significantly alter the force-displacement profile and reduce the depth-dependent modulus of articular cartilage. Excessive collagen fiber folding occurred at 40-60% relative depth, producing a "black line" in cryopreserved tissue. Force-displacement curves exhibited elongated toe-region in cryopreserved tissue while fresh tissue had nonmeasurable toe-region. Statistical analysis showed significant reduction in the elastic modulus and GAG concentration throughout the tissue between same-depth ranges. This method of cryopreservation significantly reduces the depth-dependent modulus of canine humeral osteochondral samples.

Intraoperative imaging of nipple perfusion patterns and ischemic complications in nipple-sparing mastectomies.

BACKGROUND: Nipple-sparing mastectomies (NSM) have gained acceptance in the field of breast oncology. Ischemic complications involving the nipple-areolar complex (NAC) occur in 3-37 % of cases. Skin perfusion can be monitored intraoperatively using indocyanine green (IC-GREEN™, ICG) and a specialized infrared camera-computer system (SPY Elite™). The blood flow pattern to the breast skin and the NAC were evaluated and a classification scheme was developed. METHODS: Preincision baseline and postmastectomy skin perfusion studies were performed intraoperatively using 3 mL of ICG. The pattern of arterial blood inflow was classified according to whether perfusion appeared to originate predominantly from the underlying breast tissue (V1), the surrounding skin (V2), or a combination of V1 and V2 (V3). Ischemia, resection, or delayed complications of NAC were recorded. RESULTS: Thirty-nine breasts were interrogated. Seven (18 %) demonstrated a V1 pattern, 18 (46 %) a V2 pattern, and 14 (36 %) a V3 pattern. Seven (18 %) NACs were removed; six intraoperatively and the seventh in a delayed fashion. Notably, five of the seven resected NACs had a V1 pattern. Overall, 71 % of all V1 cases demonstrated profound ischemic changes by intraoperative clinical judgment and SPY imaging. The rates of resection of the NAC differed significantly between perfusion patterns (Fisher's exact test, p = 0.0003). CONCLUSIONS: Three perfusion patterns for the NAC are defined. The V1 pattern had the highest rate of NAC ischemia in NSM. Imaging NAC and skin perfusion during NSMs is a useful adjunctive tool with potential to direct placement of mastectomy incisions and minimize ischemic complications.

Topographical variations of the strain-dependent zonal properties of tibial articular cartilage by microscopic MRI.

The topographical variations of the zonal properties of canine articular cartilage over the medial tibia were evaluated as the function of external loading by microscopic magnetic resonance imaging (µMRI). T2 and T1 relaxation maps and GAG (glycosaminoglycan) images from a total of 70 specimens were obtained with and without the mechanical loading at 17.6 µm depth resolution. In addition, mechanical modulus and water content were measured from the tissue. For the bulk without loading, the means of T2 at magic angle (43.6 ± 8.1 ms), absolute thickness (907.6 ± 187.9 µm) and water content (63.3 ± 9.3%) on the meniscus-covered area were significantly lower than the means of T2 at magic angle (51.1 ± 8.5 ms), absolute thickness (1251.6 ± 218.4 µm) and water content (73.2 ± 5.6%) on the meniscus-uncovered area. However GAG (86.0 ± 15.3 mg/ml) on the covered area was significantly higher than GAG (70.0 ± 8.8 mg/ml) on the uncovered area. Complex relationships were found in the tissue properties as the function of external loading. The tissue parameters in the superficial zone changed more profoundly than the same properties in the radial zone. The tissue parameters in the meniscus-covered areas changed differently when comparing with the same parameters in the uncovered areas. This project confirms that the load-induced changes in the molecular distribution and structure of cartilage are both depth-dependent and topographically distributed. Such detailed knowledge of the tibial layer could improve the early detection of the subtle softening of the cartilage that will eventually lead to the clinical diseases such as osteoarthritis.

A microbial risk assessor's guide to Valley Fever (Coccidioides spp.): Case study and review of risk factors.

Valley Fever is a respiratory disease caused by inhalation of arthroconidia, a type of spore produced by fungi within the genus Coccidioides spp. which are found in dry, hot ecosystems of the Western Hemisphere. A quantitative microbial risk assessment (QMRA) for the disease has not yet been performed due to a lack of dose-response models and a scarcity of quantitative occurrence data from environmental samples. A literature review was performed to gather data on experimental animal dosing studies, environmental occurrence, human disease outbreaks, and meteorological associations. As a result, a risk framework is presented with information for parameterizing QMRA models for Coccidioides spp., with eight new dose-response models proposed. A probabilistic QMRA was conducted for a Southwestern US agricultural case study, evaluating eight scenarios related to farming occupational exposures. Median daily workday risks for developing severe Valley Fever ranged from 2.53 × 10-7 (planting by hand while wearing an N95 facemask) to 1.33 × 10-3 (machine harvesting while not wearing a facemask). The literature review and QMRA synthesis confirmed that exposure to aerosolized arthroconidia has the potential to result in high attack rates but highlighted that the mechanistic relationships between environmental conditions and disease remain poorly understood. Recommendations for Valley Fever risk assessment research needs in order to reduce disease risks are discussed, including interventions for farmers.

Multimodal single-neuron, intracranial EEG, and fMRI brain responses during movie watching in human patients.

We present a multimodal dataset of intracranial recordings, fMRI, and eye tracking in 20 participants during movie watching. Recordings consist of single neurons, local field potential, and intracranial EEG activity acquired from depth electrodes targeting the amygdala, hippocampus, and medial frontal cortex implanted for monitoring of epileptic seizures. Participants watched an 8-min long excerpt from the video "Bang! You're Dead" and performed a recognition memory test for movie content. 3 T fMRI activity was recorded prior to surgery in 11 of these participants while performing the same task. This NWB- and BIDS-formatted dataset includes spike times, field potential activity, behavior, eye tracking, electrode locations, demographics, and functional and structural MRI scans. For technical validation, we provide signal quality metrics, assess eye tracking quality, behavior, the tuning of cells and high-frequency broadband power field potentials to familiarity and event boundaries, and show brain-wide inter-subject correlations for fMRI. This dataset will facilitate the investigation of brain activity during movie watching, recognition memory, and the neural basis of the fMRI-BOLD signal.

An Update of a Clinical Practice Guideline for the Management of Patients With Acute Spinal Cord Injury: Recommendations on the Role and Timing of Decompressive Surgery.

STUDY DESIGN: Clinical practice guideline development. OBJECTIVES: Acute spinal cord injury (SCI) can result in devastating motor, sensory, and autonomic impairment; loss of independence; and reduced quality of life. Preclinical evidence suggests that early decompression of the spinal cord may help to limit secondary injury, reduce damage to the neural tissue, and improve functional outcomes. Emerging evidence indicates that "early" surgical decompression completed within 24 hours of injury also improves neurological recovery in patients with acute SCI. The objective of this clinical practice guideline (CPG) is to update the 2017 recommendations on the timing of surgical decompression and to evaluate the evidence with respect to ultra-early surgery (in particular, but not limited to, <12 hours after acute SCI). METHODS: A multidisciplinary, international, guideline development group (GDG) was formed that consisted of spine surgeons, neurologists, critical care specialists, emergency medicine doctors, physical medicine and rehabilitation professionals, as well as individuals living with SCI. A systematic review was conducted based on accepted methodological standards to evaluate the impact of early (within 24 hours of acute SCI) or ultra-early (in particular, but not limited to, within 12 hours of acute SCI) surgery on neurological recovery, functional outcomes, administrative outcomes, safety, and cost-effectiveness. The GRADE approach was used to rate the overall strength of evidence across studies for each primary outcome. Using the "evidence-to-recommendation" framework, recommendations were then developed that considered the balance of benefits and harms, financial impact, patient values, acceptability, and feasibility. The guideline was internally appraised using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool. RESULTS: The GDG recommended that early surgery (≤24 hours after injury) be offered as the preferred option for adult patients with acute SCI regardless of level. This recommendation was based on moderate evidence suggesting that patients were 2 times more likely to recover by ≥ 2 ASIA Impairment Score (AIS) grades at 6 months (RR: 2.76, 95% CI 1.60 to 4.98) and 12 months (RR: 1.95, 95% CI 1.26 to 3.18) if they were decompressed within 24 hours compared to after 24 hours. Furthermore, patients undergoing early surgery improved by an additional 4.50 (95% 1.70 to 7.29) points on the ASIA Motor Score compared to patients undergoing surgery after 24 hours post-injury. The GDG also agreed that a recommendation for ultra-early surgery could not be made on the basis of the current evidence because of the small sample sizes, variable definitions of what constituted ultra-early in the literature, and the inconsistency of the evidence. CONCLUSIONS: It is recommended that patients with an acute SCI, regardless of level, undergo surgery within 24 hours after injury when medically feasible. Future research is required to determine the differential effectiveness of early surgery in different subpopulations and the impact of ultra-early surgery on neurological recovery. Moreover, further work is required to define what constitutes effective spinal cord decompression and to individualize care. It is also recognized that a concerted international effort will be required to translate these recommendations into policy.

Fibrinogen concentration significantly decreases after on-pump versus off-pump coronary artery bypass surgery: a systematic point-of-care ROTEM analysis.

OBJECTIVES: Studies have emphasized the importance of normal fibrinogen concentrations in surgical patients. The primary hypothesis of this study was that fibrinogen levels significantly decrease in on-pump coronary artery bypass graft (CABG) surgery versus off-pump coronary artery bypass graft (OPCAB) surgery. The second objective was to show that ROTEM (TEM International, GmbH, Munich, Germany) rapidly detects these abnormalities compared with standard tests. DESIGN: A prospective, nonrandomized study. SETTING: A university hospital. PARTICIPANTS: Forty-two and 62 patients in the CABG and OPCAB groups, respectively, undergoing first-time bypass surgery were included. INTERVENTIONS: CABG versus OPCAB surgery. MEASUREMENTS AND MAIN RESULTS: Routine coagulation tests and ROTEM values were measured before anesthesia (T0), after the first dose of heparin (T1), after protamine (T2), upon intensive care unit arrival (T3), and 4 hours postoperatively (T4). The outcome measures were followed until 4 hours postoperatively. Fibrinogen concentrations were significantly lower in the CABG versus the OPCAB group at T2 (170 ± 44 v 243 ± 73 mg/dL, p < 0.001) and T3 (179 ± 42 v 232 ± 68 mg/dL, p < 0.001). This was confirmed by significantly lower FIBTEM maximal clot firmness values at T2 (9 ± 4 v 14 ± 5 mm, p < 0.001) and T3 (9 ± 4 v 13 ± 6 mm, p < 0.001). In the CABG group, patients received significantly more transfusions of all blood products except fresh frozen plasma. CONCLUSIONS: Fibrinogen concentration significantly decreases after cardiopulmonary bypass. ROTEM helps in its fast detection.

Confounding of norm-based and adaptation effects in brain responses.

Separate neuroscience experiments have examined two properties of neural coding for perceptual stimuli. Adaptation studies seek a graded recovery from neural adaptation with ever greater dissimilarity between pairs of stimuli. Studies of prototype effects test for a larger absolute response to a stimulus which is distant from the center of a stimulus space. While intellectually distinct, these effects are confounded in measurement in standard neuroscience paradigms and can be mistaken for one another. Stimuli which are more distinctive are less subject to adaptation from perceptual neighbors. Therefore, a putative prototype effect may simply result from greater adaptation of prototypical stimuli by other stimuli in the experiment. Conversely, stimulus pairs which are the most perceptually distant from one another, and therefore expected to show the greatest recovery from adaptation, disproportionately draw from the extremes of the stimulus space. Thus, an apparent neural similarity effect may be created by an underlying prototype representation. We simulate BOLD fMRI results driven by each possible effect and demonstrate spurious results in support of the complementary effect. We then present an example fMRI experiment that demonstrates the confound and how it may be minimized. Finally, we discuss the implications of this intrinsic confound for studies of perceptual representation, neural coding, and category learning.

An increase in endogenous erythropoietin concentrations has no cardioprotective effects in patients undergoing coronary artery bypass graft surgery.

OBJECTIVE: Preliminary data showed an increase in endogenous erythropoietin (EPO) concentrations after acute normovolemic hemodilution (ANH) in patients undergoing coronary artery bypass graft (CABG) surgery. Numerous studies have shown the organ protective properties of EPO. The aim of this study was to investigate the cardioprotective effects of these increased EPO concentrations that resulted from ANH during cardiac surgery. DESIGN: A prospective, randomized, blind study. SETTING: A university hospital. PARTICIPANTS: A total of 93 patients undergoing isolated CABG surgery with or without cardiopulmonary bypass (CPB). INTERVENTIONS: Subjects with CPB were randomized into the control (C) or ANH group. Those in the off-pump coronary artery bypass group underwent no treatment. In the ANH group, a precalculated amount of blood was withdrawn and replaced by colloids after the induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Hemodynamic parameters were recorded intra- and postoperatively. Troponin concentrations were measured as a routine parameter postoperatively. Upon intensive care unit arrival, the EPO levels were higher in the ANH group than in the C group. There was no significant difference between the troponin values of the C and the ANH groups at 4 hours postoperatively. CONCLUSIONS: In patients undergoing CABG surgery on CPB, an increase in endogenous EPO concentrations in the physiologic range has no cardioprotective effects.