Proximal CA1 20-40 Hz power dynamics reflect trial-specific information processing supporting nonspatial sequence memory.

The hippocampus is known to play a critical role in processing information about temporal context. However, it remains unclear how hippocampal oscillations are involved, and how their functional organization is influenced by connectivity gradients. We examined local field potential activity in CA1 as rats performed a nonspatial odor sequence memory task. We found that odor sequence processing epochs were characterized by distinct spectral profiles and proximodistal CA1 gradients of theta and 20-40 Hz power than track running epochs. We also discovered that 20-40 Hz power was predictive of sequence memory performance, particularly in proximal CA1 and during the plateau of high power observed in trials in which animals had to maintain their decision until instructed to respond. Altogether, these results provide evidence that dynamics of 20-40 Hz power along the CA1 axis are linked to trial-specific processing of nonspatial information critical to order judgments and are consistent with a role for 20-40 Hz power in gating information processing

Evaluation of the criteria for angiotomography indications in the diagnosis of carotid and vertebral arterial injury associated with blunt trauma

Abstract Background Blunt carotid and vertebral artery injury (BCVI) occur infrequently. The incidence of this type of injury is difficult to determine as many emergency room patients are neurologically asymptomatic. The statistics have not been reported in Brazil. The objectives of the current study were: To evaluate the accuracy of criteria used to recommend angiotomography in the diagnosis of cervical BCVI in 100 patients with blunt cervical trauma in the trauma services section of a Brazilian quaternary care hospital. Methods During a 30-month (2006-2008), all patients admitted to the emergency room of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo with blunt cervical trauma and potential risk of cervical vessel injury, were subjected to cervical angiotomography to diagnose BCVI. The data analyzed are presented as mean ± standard deviation, and statistical analyses included Chi-square and Fisher's exact tests, and the Mann-Whitney test. Results During the study period 2467 blunt trauma patients were admitted. In 100 patients that met the criteria for inclusion in the study, angiotomography identified 23 with BCVI, including 17 males and six females. The mean patient age was 34.81 ± 14.84 years. Car crash (49%) and car-pedestrian accidents (24%) were the most frequent causes of injury. Ten patients had internal carotid artery injuries, two patients had common carotid artery injuries, and 11 patients had vertebral artery injuries. Seven patients presented with Degree I arterial injuries, 10 patients presented with Degree II artery injuries, four patients presented with Degree IV artery injuries, one patient presented with a Degree V artery injury, and one patient had a carotid fistula. Seven out of the 23 patients with BCVI (30.4%) presented with cervical vertebrae fractures, and 11 out of the 23 patients with BCVI (47.8%) presented with facial fractures (LeFort II and III). Conclusions Although there is no consensus regarding the criteria that should be used to indicate angiotomography for BCVI diagnosis, we conclude that the criteria used in the current study led to a diagnosis of BCVI in 0.93% of 2,467 trauma patients, BCVI injuries were associated with more severe traumas and did not affect mortality.</p

Decompressive craniectomy and cerebral blood flow regulation in head injured patients: A case studied by perfusion CT

Previous studies have reported increased cerebral blood flow (CBF) velocity after decompressive craniectomy in traumatic brain injury (TBI) patients. A 27-year-old man presented with clinical and tomographic signs of cerebral herniation secondary to TBI. Prior to decompressive craniectomy, hemodynamic study by perfusion computed tomography (CT) indicated diffuse cerebral hyperperfusion. Following surgical decompression, the patient recovered neurologically and perfusion CT disclosed a decrease in the intensity of cerebral perfusion. The patient's blood pressure levels were similar at both pre- and postoperative perfusion CT examinations. This finding provides indirect evidence that decompressive craniectomy may improve mechanisms of CBF regulation in TBI, providing pathophysiological insights in the cerebral hemodynamics of TBI patients. This is the first report analyzing the hemodynamic changes through perfusion CT (PCT) in a patient with decompressive craniotomy due to TBI. (C) 2012 Elsevier Masson SAS. All rights reserved

Computed Tomography Angiography for Detection of Middle Meningeal Artery Lesions Associated with Acute Epidural Hematomas

Background. The natural history of traumatic aneurysms of the middle meningeal artery (MMA) is not well known, but patients with these lesions are more likely to have delayed bleeds. In this paper, we described a series of patients with epidural hematoma who underwent angiotomography (CTA) for MMA vascular lesion diagnosis. Methods. Eleven patients admitted to our emergency unit with small acute epidural hematoma were prospectively studied. All patients with temporal acute epidural hematomas underwent CTA and cerebral angiogram at our institution for diagnosis of posttraumatic lesions of middle meningeal artery. The findings of angiotomography and digital angiography were reviewed by radiologist and angiographers, respectively, to ensure that the lesions were readily diagnosed without knowing the results of angiotomography and to compare CTA findings with standard angiogram. Results. The causes of head injury were traffic accidents, falls, and aggression. Three of these patients presented traumatic MMA pseudoaneurysm. CT angiography was able to diagnose all of them, with dimensions ranging from 1.5 to 2.8 mm. Conventional angiography confirmed the findings of CT angiography, and the lesions presented with similar dimensions at both methods. Conclusions. We believe that angiotomography can be a useful technique for diagnosis of vascular lesion associated with small epidural hematoma

A Bayesian reanalysis of the Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial

Background Timing of initiation of kidney-replacement therapy (KRT) in critically ill patients remains controversial. The Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial compared two strategies of KRT initiation (accelerated versus standard) in critically ill patients with acute kidney injury and found neutral results for 90-day all-cause mortality. Probabilistic exploration of the trial endpoints may enable greater understanding of the trial findings. We aimed to perform a reanalysis using a Bayesian framework. Methods We performed a secondary analysis of all 2927 patients randomized in multi-national STARRT-AKI trial, performed at 168 centers in 15 countries. The primary endpoint, 90-day all-cause mortality, was evaluated using hierarchical Bayesian logistic regression. A spectrum of priors includes optimistic, neutral, and pessimistic priors, along with priors informed from earlier clinical trials. Secondary endpoints (KRT-free days and hospital-free days) were assessed using zero–one inflated beta regression. Results The posterior probability of benefit comparing an accelerated versus a standard KRT initiation strategy for the primary endpoint suggested no important difference, regardless of the prior used (absolute difference of 0.13% [95% credible interval [CrI] − 3.30%; 3.40%], − 0.39% [95% CrI − 3.46%; 3.00%], and 0.64% [95% CrI − 2.53%; 3.88%] for neutral, optimistic, and pessimistic priors, respectively). There was a very low probability that the effect size was equal or larger than a consensus-defined minimal clinically important difference. Patients allocated to the accelerated strategy had a lower number of KRT-free days (median absolute difference of − 3.55 days [95% CrI − 6.38; − 0.48]), with a probability that the accelerated strategy was associated with more KRT-free days of 0.008. Hospital-free days were similar between strategies, with the accelerated strategy having a median absolute difference of 0.48 more hospital-free days (95% CrI − 1.87; 2.72) compared with the standard strategy and the probability that the accelerated strategy had more hospital-free days was 0.66. Conclusions In a Bayesian reanalysis of the STARRT-AKI trial, we found very low probability that an accelerated strategy has clinically important benefits compared with the standard strategy. Patients receiving the accelerated strategy probably have fewer days alive and KRT-free. These findings do not support the adoption of an accelerated strategy of KRT initiation

Initiation of continuous renal replacement therapy versus intermittent hemodialysis in critically ill patients with severe acute kidney injury: a secondary analysis of STARRT-AKI trial

Background: There is controversy regarding the optimal renal-replacement therapy (RRT) modality for critically ill patients with acute kidney injury (AKI). Methods: We conducted a secondary analysis of the STandard versus Accelerated Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial to compare outcomes among patients who initiated RRT with either continuous renal replacement therapy (CRRT) or intermittent hemodialysis (IHD). We generated a propensity score for the likelihood of receiving CRRT and used inverse probability of treatment with overlap-weighting to address baseline inter-group differences. The primary outcome was a composite of death or RRT dependence at 90-days after randomization. Results: We identified 1590 trial participants who initially received CRRT and 606 who initially received IHD. The composite outcome of death or RRT dependence at 90-days occurred in 823 (51.8%) patients who commenced CRRT and 329 (54.3%) patients who commenced IHD (unadjusted odds ratio (OR) 0.90; 95% confidence interval (CI) 0.75-1.09). After balancing baseline characteristics with overlap weighting, initial receipt of CRRT was associated with a lower risk of death or RRT dependence at 90-days compared with initial receipt of IHD (OR 0.81; 95% CI 0.66-0.99). This association was predominantly driven by a lower risk of RRT dependence at 90-days (OR 0.61; 95% CI 0.39-0.94). Conclusions: In critically ill patients with severe AKI, initiation of CRRT, as compared to IHD, was associated with a significant reduction in the composite outcome of death or RRT dependence at 90-days

Regional Practice Variation and Outcomes in the Standard Versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) Trial: A Post Hoc Secondary Analysis.

ObjectivesAmong patients with severe acute kidney injury (AKI) admitted to the ICU in high-income countries, regional practice variations for fluid balance (FB) management, timing, and choice of renal replacement therapy (RRT) modality may be significant.DesignSecondary post hoc analysis of the STandard vs. Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial (ClinicalTrials.gov number NCT02568722).SettingOne hundred-fifty-three ICUs in 13 countries.PatientsAltogether 2693 critically ill patients with AKI, of whom 994 were North American, 1143 European, and 556 from Australia and New Zealand (ANZ).InterventionsNone.Measurements and main resultsTotal mean FB to a maximum of 14 days was +7199 mL in North America, +5641 mL in Europe, and +2211 mL in ANZ (p p p p p p p p = 0.007).ConclusionsAmong STARRT-AKI trial centers, significant regional practice variation exists regarding FB, timing of initiation of RRT, and initial use of continuous RRT. After adjustment, such practice variation was associated with lower ICU and hospital stay and 90-day mortality among ANZ patients compared with other regions