There is convincing preclinical evidence that early decompression in the setting of spinal cord injury (SCI) improves neurologic outcomes. However, the effect of early surgical decompression in ...patients with acute SCI remains uncertain. Our objective was to evaluate the relative effectiveness of early (<24 hours after injury) versus late (≥ 24 hours after injury) decompressive surgery after traumatic cervical SCI.
We performed a multicenter, international, prospective cohort study (Surgical Timing In Acute Spinal Cord Injury Study: STASCIS) in adults aged 16-80 with cervical SCI. Enrolment occurred between 2002 and 2009 at 6 North American centers. The primary outcome was ordinal change in ASIA Impairment Scale (AIS) grade at 6 months follow-up. Secondary outcomes included assessments of complications rates and mortality.
A total of 313 patients with acute cervical SCI were enrolled. Of these, 182 underwent early surgery, at a mean of 14.2(± 5.4) hours, with the remaining 131 having late surgery, at a mean of 48.3(± 29.3) hours. Of the 222 patients with follow-up available at 6 months post injury, 19.8% of patients undergoing early surgery showed a ≥ 2 grade improvement in AIS compared to 8.8% in the late decompression group (OR = 2.57, 95% CI:1.11,5.97). In the multivariate analysis, adjusted for preoperative neurological status and steroid administration, the odds of at least a 2 grade AIS improvement were 2.8 times higher amongst those who underwent early surgery as compared to those who underwent late surgery (OR = 2.83, 95% CI:1.10,7.28). During the 30 day post injury period, there was 1 mortality in both of the surgical groups. Complications occurred in 24.2% of early surgery patients and 30.5% of late surgery patients (p = 0.21).
Decompression prior to 24 hours after SCI can be performed safely and is associated with improved neurologic outcome, defined as at least a 2 grade AIS improvement at 6 months follow-up.
Finding alternative optoelectronic mechanisms that overcome the limitations of conventional semiconductor devices is paramount for detecting and harvesting low-energy photons. A highly promising ...approach is to drive a current from the thermal energy added to the free-electron bath as a result of light absorption. Successful implementation of this strategy requires a broadband absorber where carriers interact among themselves more strongly than with phonons, as well as energy-selective contacts to extract the excess electronic heat. Here we show that graphene-WSe2-graphene heterostructure devices offer this possibility through the photo-thermionic effect: the absorbed photon energy in graphene is efficiently transferred to the electron bath leading to a thermalized hot carrier distribution. Carriers with energy higher than the Schottky barrier between graphene and WSe2 can be emitted over the barrier, thus creating photocurrent. We experimentally demonstrate that the photo-thermionic effect enables detection of sub-bandgap photons, while being size-scalable, electrically tunable, broadband and ultrafast.
Options for mechanical circulatory support as a bridge to heart transplantation in children with severe heart failure are limited.
We conducted a prospective, single-group trial of a ventricular ...assist device designed specifically for children as a bridge to heart transplantation. Patients 16 years of age or younger were divided into two cohorts according to body-surface area (cohort 1, <0.7 m(2); cohort 2, 0.7 to <1.5 m(2)), with 24 patients in each group. Survival in the two cohorts receiving mechanical support (with data censored at the time of transplantation or weaning from the device owing to recovery) was compared with survival in two propensity-score-matched historical control groups (one for each cohort) undergoing extracorporeal membrane oxygenation (ECMO).
For participants in cohort 1, the median survival time had not been reached at 174 days, whereas in the matched ECMO group, the median survival was 13 days (P<0.001 by the log-rank test). For participants in cohort 2 and the matched ECMO group, the median survival was 144 days and 10 days, respectively (P<0.001 by the log-rank test). Serious adverse events in cohort 1 and cohort 2 included major bleeding (in 42% and 50% of patients, respectively), infection (in 63% and 50%), and stroke (in 29% and 29%).
Our trial showed that survival rates were significantly higher with the ventricular assist device than with ECMO. Serious adverse events, including infection, stroke, and bleeding, occurred in a majority of study participants. (Funded by Berlin Heart and the Food and Drug Administration Office of Orphan Product Development; ClinicalTrials.gov number, NCT00583661.).
Graphene is a promising material for ultrafast and broadband photodetection. Earlier studies have addressed the general operation of graphene-based photothermoelectric devices and the switching ...speed, which is limited by the charge carrier cooling time, on the order of picoseconds. However, the generation of the photovoltage could occur at a much faster timescale, as it is associated with the carrier heating time. Here, we measure the photovoltage generation time and find it to be faster than 50 fs. As a proof-of-principle application of this ultrafast photodetector, we use graphene to directly measure, electrically, the pulse duration of a sub-50 fs laser pulse. The observation that carrier heating is ultrafast suggests that energy from absorbed photons can be efficiently transferred to carrier heat. To study this, we examine the spectral response and find a constant spectral responsivity of between 500 and 1,500 nm. This is consistent with efficient electron heating. These results are promising for ultrafast femtosecond and broadband photodetector applications.
Background
Recently, the randomized EINSTEIN‐Jr study showed similar efficacy and safety for rivaroxaban and standard anticoagulation for treatment of pediatric venous thromboembolism (VTE). The ...rivaroxaban dosing strategy was established based on phase 1 and 2 data in children and through pharmacokinetic (PK) modeling.
Methods
Rivaroxaban treatment with tablets or the newly developed granules‐for‐oral suspension formulation was bodyweight‐adjusted and administered once‐daily, twice‐daily, or thrice‐daily for children with bodyweights of ≥30, ≥12 to <30, and <12 kg, respectively. Previously, these regimens were confirmed for children weighing ≥20 kg but only predicted in those <20 kg. Based on sparse blood sampling, the daily area under the plasma concentration–time curve AUC(0‐24)ss and trough Ctrough,ss and maximum Cmax,ss steady‐state plasma concentrations were derived using population PK modeling. Exposure‐response graphs were generated to evaluate the potential relationship of individual PK parameters with recurrent VTE, repeat imaging outcomes, and bleeding or adverse events. A taste‐and‐texture questionnaire was collected for suspension‐recipients.
Results
Of the 335 children (aged 0‐17 years) allocated to rivaroxaban, 316 (94.3%) were evaluable for PK analyses. Rivaroxaban exposures were within the adult exposure range. No clustering was observed for any of the PK parameters with efficacy, bleeding, or adverse event outcomes. Results were similar for the tablet and suspension formulation. Acceptability and palatability of the suspension were favorable.
Discussion
Based on this analysis and the recently documented similar efficacy and safety of rivaroxaban compared with standard anticoagulation, we conclude that bodyweight‐adjusted pediatric rivaroxaban regimens with either tablets or suspension are validated and provide for appropriate treatment of children with VTE.
Recent data suggest that the Berlin Heart EXCOR Pediatric ventricular assist device is superior to extracorporeal membrane oxygenation for bridge to heart transplantation. Published data are limited ...to 1 in 4 children who received the device as part of the US clinical trial. We analyzed outcomes for all US children who received the EXCOR to characterize device outcomes in an unselected cohort and to identify risk factors for mortality to facilitate patient selection.
This multicenter, prospective cohort study involved all children implanted with the Berlin Heart EXCOR Pediatric ventricular assist device at 47 centers from May 2007 through December 2010. Multiphase nonproportional hazards modeling was used to identify risk factors for early (<2 months) and late mortality. Of 204 children supported with the EXCOR, the median duration of support was 40 days (range, 1-435 days). Survival at 12 months was 75%, including 64% who reached transplantation, 6% who recovered, and 5% who were alive on the device. Multivariable analysis identified lower weight, biventricular assist device support, and elevated bilirubin as risk factors for early mortality and bilirubin extremes and renal dysfunction as risk factors for late mortality. Neurological dysfunction occurred in 29% and was the leading cause of death.
Use of the Berlin Heart EXCOR has risen dramatically over the past decade. The EXCOR has emerged as a new treatment standard in the United States for pediatric bridge to transplantation. Three-quarters of children survived to transplantation or recovery; an important fraction experienced neurological dysfunction. Smaller patient size, renal dysfunction, hepatic dysfunction, and biventricular assist device use were associated with mortality, whereas extracorporeal membrane oxygenation before implantation and congenital heart disease were not.
Abstract Background Pediatric arterial ischemic stroke remains incompletely understood. Population-based epidemiological data inform clinical trial design but are scant in this condition. We aimed to ...determine age-specific epidemiological characteristics of arterial ischemic stroke in neonates (birth - 28 days) and older children (29 days - 18 years). Methods We conducted a 16-year, prospective, national population-based study, the Canadian Pediatric Ischemic Stroke Registry across all 16 Canadian acute children’s hospitals. We prospectively enrolled children with arterial ischemic stroke from January 1992 - December 2001 and documented disease incidence, presentations, risk factors and treatments. Study outcomes were assessed throughout 2008 including abnormal clinical outcomes (stroke-related death or neurological deficit) and recurrent arterial ischemic stroke or transient ischemic attack. Results Among 1,129 children enrolled with arterial ischemic stroke, stroke incidence was 1.72/100,000/year, (neonates 10.2/100,000 live births). Detailed clinical and radiological information were available for 933 children (232 neonates and 701 older children, 55% male). Predominant clinical presentations were seizures in neonates (88%), focal deficits in older children (77%), and diffuse neurological signs (54%) in both. Among neonates, 44% had no discernible risk factors. In older children, arteriopathy (49% of patients with vascular imaging), cardiac (28%) and prothrombotic disorders (35% of patients tested) predominated. Antithrombotic treatment increased during the study period (p<0.001). Stroke-specific mortality was 5%. Outcomes included neurological deficits in 60% of neonates and 70% of older children. Among neonates, deficits emerged during follow-up in 39%. Overall an initial decreased level of consciousness, non-specific systemic presentation and the presence of stroke risk factors predicted abnormal outcomes. For neonates, predictors were decreased level of consciousness, non-specific systemic presentation, and basal ganglia infarcts. For older children, predictors were initial seizures, non-specific systemic presentation, risk factors and lack of antithrombotic treatment. Recurrent arterial ischemic stroke or transient ischemic attack developed in 12% of older children and was predicted by arteriopathy, presentation without seizures, and lack of antithrombotic treatment. Emerging deficit was predicted by neonatal age at stroke and by cardiac disease. Conclusions This national data set provides a population-based disease incidence rate and demonstrates a protective effect of antithrombotic treatment in older children, and frequent long-term emerging deficits in neonates and in children with cardiac disorders. Further clinical trials are required to develop effective age-appropriate treatments for children with acute arterial ischemic stroke.
Studies on outcomes after four-level anterior cervical discectomy and fusion (ACDF) are limited in the literature. The purpose of this study was to report on clinical outcomes and revision rates ...following four-level ACDF. Patients operated with four-level ACDF were identified in a prospectively accrued single institution database. Outcome scores included the Neck Disability Index (NDI) and Visual Analogue Scale (VAS) for neck and arm pain. Reoperation rates were determined. Any complications were identified from a review of the medical records. Twenty-eight patients with a minimum of 12 months follow up were included in the analysis. The mean age at surgery was 58.5 years. The median radiographic follow up time was 23 (IQR = 16-31.25) months. Cervical lordosis was significantly improved postoperatively (- 1 to - 13, p < 0.001). At the median 24 (IQR = 17.75-39.50) months clinical follow up time, there was a significant improvement in the NDI (38 to 28, p = 0.046) and VAS for neck pain scores (5.1 to 3, p = 0.012). The most common perioperative complication was transient dysphagia (32%) followed by hoarseness (14%). Four (14%) patients required revision surgery at a median 11.5 (IQR = 2-51) months postoperatively. The results of this study indicate that patients who undergo four-level ACDF have a significant improvement in clinical outcomes at median 24 months follow up. Stand-alone four-level ACDF is a valid option for the management of complex cervical degenerative conditions.
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