26 research outputs found
Frequency of Gross Total Resection in Intra-axial Brain Tumors with Help of Neuronavigation
Introduction: Neuronavigation has become a ubiquitous tool in the surgical management of brain tumors. Neuronavigation is most useful as an adjunct to other brain-mapping techniques such as awake mapping and electrocorticography in the resection of lesions within eloquent motor and language areas. Neuronavigation is also commonly used in skull base tumors, especially for planning an operative trajectory in regions containing vital neurovascular structures and may be used for cerebrovascular surgery. The current study was planned to determine the frequency of gross total resection in intra-axial brain tumors with the help of neuronavigation.Material and Methods: This cross sectional study was carried out in the Department of Neurosurgery, Nishtar Medical College & Hospital, Multan, from September 2014 to March 2015. After approval from institutional ethical committee, seventy seven patients fulfilling the inclusion criteria were selected from the patient admitted in the Neurosurgical Department through the Out Patient Department and patients referred from other departments. After thorough counseling with the patient and his/her relatives, informed consent for procedure was taken.Results: Total 78 patients were included in the study. Out of these 78 (100%), 41 (52.6%) were male and 37 (47.4%) were female. As concern to the outcome variable (gross total resection), out of 78 (100%), in 61 (78.2%) patients gross total resection was present. On cross tabulation it was further clarified that in male patients’ gross total resection present in 32 patients and absent in 9 patients. Similarly in female patients gross total resection present in 29 patients and absent in 8 patients. P value was 0.747. Conclusion: Conclusion of our study is that neuronevigation is a usefull technique in for better gross total resection of intra axial brain tumor
Safety and effectiveness of ultrasound guided peripheral nerve blocks: Audit at tertiary care hospital
Objective: To assess the safety and effectiveness of peripheral nerve blocks using ultrasound.Methods: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of all patients who received peripheral nerve blocks as part of anaesthesia care between January 2015 and January 2017. The data included outcomes of peripheral nerve block effectiveness, complications and limb conditions after the block. Peripheral nerve block effectiveness was assessed by monitoring pain scores at rest and on movement, and the requirement of co-analgesia. Complications, like numbness, motor block, metallic taste, hypotension and respiratory depression, were also assessed. Data was analysed using SPSS 19.Results: There were 299 patients who received ultrasound-guided peripheral nerve blocks. The overall mean age was 44.57±16.64 years. Of the total, 140 (47%) received transversus abdominis plane block, followed by supraclavicular block 49(16.7%). The most common complication in the recovery room was numbness 19 (6.2%). Overall, 70% patients remained pain-free, while 16% had moderate pain on movement 12 hours postoperatively.Conclusions: Ultrasound-guided regional anaesthesia was found to provide effective analgesia during and after surgery. Nerve blocks proved to be safe when used with ultrasound
Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial
Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma.
Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We
aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding.
Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries.
Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the
minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and
had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were
randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical
apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to
100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a
maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h
for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to
allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients
who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable.
This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124.
Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid
(5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated
treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the
tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18).
Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and
placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein
thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of
5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98).
Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our
results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a
randomised trial
The CMS GEM Detector Front-end Electronics – Characterization and Implementation
This research work is a contribution to the CMS GEM upgrade. From 2026, the CERN Large Hadron Collider (LHC) will enter the High Luminosity phase, also known as phase-2, where the machine will almost double the number of proton collisions per second. This luminosity increase brings challenges to the LHC experiments, like CMS, particularly to their most forward detector sub-systems closer to the beamline. The higher particle rates and radiation levels challenge the detectors and their read-out electronics, the trigger, and the data acquisition systems of the experiment.In CMS, new Triple-GEM detectors are being installed in the forward part of the muon spectrometer. A first ring, called GE1/1, has been deployed during the current LHC Long Shutdown (2019-2021), and two other rings, GE2/1 and ME0, will be installed within a couple of years. The objective of the new TripleGEM detector sub-system is to improve the CMS’s muon tracking and triggering capabilities. This thesis is devoted to the VFAT3, a front-end chip that has been designed for the CMS GEM upgrade project. The VFAT3 is a 128 channel ASIC providing both trigger and tracking data. In CMS, the VFAT3 chip is assembled on a small (5 x 5 cm2 ) PCB, called the VFAT3 hybrid. For GE1/1, 5,000 VFAT3 chips and hybrids had to be mass-produced. This mass production required a full characterization of the chip on the hybrid, including its radiation hardness and the study of the VFAT3 performance once it is integrated into the CMS GEM detectors. The objective of my work was to demonstrate the adequacy of the VFAT3 chip and VFAT3 hybrid for the CMS GEM phase-2 application and design the challenging hardware, software, and firmware tools required to reach that goal. The thesis is structured as follows: Chapter 1 introduces the CERN, the LHC, and the CMS projects. The phase-2 upgrade of the LHC is also described, and planned muon endcap upgrades are discussed. Chapter 2 details the GEM detectors and the first CMS GEM ring, GE1/1. The GE1/1 performance parameters achieved over ten years of GEM global collaboration R&D are also presented. Chapter 3 elaborated the VFAT3 chip, its design, and architecture. The key design goals of the chip design and optimization for GEM charge are also discussed. Chapter 4 presents the functional characterization of the VFAT3. The dedicated setup is described in detail, and the VFAT3 characterization performance is discussed. The phase-2 compatibility results of the VFAT3 are demonstrated as well. Chapter 5 is then devoted to the comprehensive study of the radiation hardness of the chip. Different test facilities and test setups designed to perform the radiation characterization are discussed. VFAT3 radiation-tolerance conformance to GEM operation is presented. In Chapter 6, the performance of the VFAT3 with the first CMS GE1/1 detector prototypes is evaluated. Various compatibility challenges and their mitigation strategies are presented as well. Chapter 7 presents the production of the VFAT3 hybrid, the manufacturing issues which had to be tackled, and finally, the results and final yield of the production of 5000 pieces for GE1/1 is described. Ultimately, Chapter 8 introduces the future CMS GEM rings, GE2/1 and ME0. The impact of my GE1/1 work and its future prospects towards GE2/1 & ME0 are also discussed.Doctorat en Sciences de l'ingénieur et technologieinfo:eu-repo/semantics/nonPublishe
Production and Quality Control of VFAT3 Front-end Hybrids for the CMS GE1/1 Upgrade
The CMS experiment is planning to install Gaseous Electron Multiplier (GEM) chambers as part of the Muon upgrade for High Luminosity Operation at the LHC. The front-end ASIC (VFAT3) has been produced in volume together with its hybrid PCB. This paper describes the design of a custom test bench for the production Quality Control (QC) of the VFAT3 hybrids. The full QC procedure incorporates calibration and performance measurements, database entries and statistical data analysis. The paper details the optimization of firmware and software functions, reducing the test time per hybrid from 30 to 2 minutes. The test system produced an overall 89 production yield including the wafer dicing and hybrid assembly losses
TWEPP 2021 Topical Workshop on Electronics for Particle Physics
The CMS detector will see the replacement of its existing endcap calorimeter with a new high granularity calorimeter (HGCAL), which will need to withstand much higher radiation levels than the present endcaps. This poses tight constraints on the front-end electronics, including the powering chain. As part of this chain, a low-dropout linear regulator (LDO) has been designed and prototyped for post-regulation for HGCAL, providing extremely low noise stable power to the analog front-end. We present results from tests of the LDO, including from a detailed irradiation campaign (TID, SEE, neutrons)
Irradiation of VFAT3: A 128-channel charge-sensitive front-end chip for the CMS GEM phase-2 upgrade
VFAT3 is the 128-channel charge-sensitive front-end chip explicitly designed for the CMS GEM phase-2 upgrades. LHC is undergoing major high luminosity upgrades for HL-LHC where the particle rate is expected to increase up to 5 times with respect to the nominal LHC luminosity of 10\textsuperscript{34}cm\textsuperscript{-2}s\textsuperscript{-1}. It is therefore necessary to monitor the evolution of the VFAT3 response due to aging in the radiation environment by total ionizing dose (TID) tests. The device operation could also be interrupted by a single high-energy particle. Thus, the estimation of the single event upset (SEU) cross-section is essential as well. This contribution summarizes all the irradiation test results that validate the suitability of VFAT3 for CMS GEM phase-2 upgrade
The radiation tolerance of a low voltage LDO developed for the CMS HGCAL on-detector electronics system
The CMS detector will undergo the replacement of its current endcap calorimeter by a new high granularity calorimeter (HGCAL). The new HGCAL will need to withstand much higher radiation levels than the present endcaps. This poses tight requirements on the front-end electronics, including the powering chain. As part of this chain, a low-dropout linear regulator (LDO) has been designed and prototyped for post-regulation for HGCAL, providing extremely low noise and stable power to the analog front-end. We present results from tests of the LDO, including from a detailed irradiation campaign.SCOPUS: cp.jDecretOANoAutActifinfo:eu-repo/semantics/publishe
REVIEW ARTICLE – Intravenous paracetamol in pediatrics: A global perspective
Intravenous (IV) Paracetamol is an excellent post operative analgesic and antipyretic in children. Efficacy and tolerability of IV Propacetamol have been established in pediatric practice. It is believed that paracetamol works by inhibiting cyclooxygenase-2 (COX-2) enzymes. Studies bring to light that therapeutic doses of IV acetaminophen are effective and tolerable in children with least chances of hepatotoxicity. However, overdose toxicity has been reported in children and drug induced hypotension in febrile critically ill patients. Therapeutic doses according to body weight of neonates and children can be administered in hospital settings. Special education of health care staff regarding precise dose and solution is necessary to assess the role of IV paracetamol preparation in pediatric practice