Intravenous ibutilide versus intravenous amiodarone for post-operative management of atrial fibrillation following coronary artery bypass grafting: a prospective randomized controlled double blinded trial

Background: Increased incidence of post-operative atrial fibrillation (POAF) is responsible for more post-operative complications, length of hospital stay and subsequent higher costs of hospitalization. This study was done to compare the efficacy and safety of ibutilide versus amiodarone for treatment of POAF following coronary artery bypass grafting (CABG).Methods: In this prospective, randomized, double blind controlled study, 60 patients posted for CABG developing POAF, divided randomly into 30 patients each in groups A and group I. Group A received IV amiodarone at 3 mg/kg over 20 minutes and group I received IV ibutilide at 0.01 mg/kg over 10 minutes (weight 60 kg). Patients underwent standard anesthetic technique and monitoring for CABG. All the demographic data, hemodynamic data were recorded in a structured manner.Results: Ibutilide showed significantly faster resolution of AF at 12.47±5.3 versus 22.9±7.68 minutes by amiodarone (p=0.000). Ibutilide was found to have significantly higher incidences of recurrence at 23.3% versus 0% by amiodarone (p=0.0048). Ibutilide showed significantly lesser hypotension 0% versus 26.67% with amiodarone (p=0.002).Conclusions: This study concluded that ibutilide was found to be better suited to treat POAF patients, who underwent CABG; due to its early and efficient resolution and reduced risk of hypotension

Construction of static and dynamic multi-layer petrophysical models in Camisea gas reservoirs, Peru

textEstimation of static and dynamic petrophysical properties of multi-layer hydrocarbon reservoirs is crucial for the assessment of storage and flow capacities, compartmentalization, and for best primary or enhanced recovery practices. Interactive numerical simulation to reproduce field logs and core data is a reliable procedure to estimate static and dynamic petrophysical properties of complex rock formations. Previously, Voss et al. (2009) introduced the concept of Common Stratigraphic Framework (CSF) to construct and cross-validate multi-layer static/dynamic petrophysical models by invoking the interactive, numerical simulation of well logs both before and after invasion. This thesis documents the successful implementation of the CSF concept to examine and quantify the effects of mud-filtrate invasion on apparent resistivity, nuclear, and magnetic resonance logs acquired in San Martin, Cashiriari and Pagoreni gas fields in Camisea, Peru. Conventional petrophysical interpretation methods yield abnormally high estimates of water saturation in some of the reservoir units that produce gas with null water influx. This anomalous behavior is due to relatively low values of deep apparent electrical resistivity, and has otherwise been attributed to the presence of clay-coating grains and/or electrically conductive grain minerals. On the other hand, electrical resistivity logs exhibit substantial invasion effects as evidenced by the separation of apparent resistivity logs (both LWD and wireline) with multiple radial lengths of investigation. In extreme cases, apparent resistivity logs “stack” because of very deep invasion. We diagnose and quantify invasion effects on resistivity and nuclear logs with interactive numerical modeling before and after invasion. The assimilation of such effects in the interpretation consistently decreases previous estimates of water saturation to those of irreducible water saturation inferred from core data. It is shown that capillary pressure effects are responsible for the difference in separation of resistivity curves in some of the reservoir units. The final multi-layer CSF is in agreement with gas production measurements and permits reliable flow predictions to assist in reservoir engineering and production studies.Petroleum and Geosystems Engineerin

Multi-Objective Optimization of Torque Distribution inHybrid Vehicles

Electrification is one of the mega-trends in the transportation and automotive industry today. Boththe alarming environmental conditions and the ever decreasing fuel reserves are driving the shifttowards hybrid, all electric and alternative fuel source vehicles. This thesis work is another smallstep towards studying, addressing and handling this issue while also laying the groundwork for developingand moving towards more efficient and commercially viable vehicles.This thesis work aims at investigating the trade-off offered by optimal control techniques betweenenergy consumption and reference tracking for torque allocation to the various actuators available topropel a hybrid electric vehicle. The particular vehicle under consideration has two electric motorsat the rear wheels and an internal combustion engine along with an integrator starter generatordriving the front wheels. The torque allocation problem is originally solved by proposing a one stageoptimization strategy (OSOS) that takes into account actuator limits, losses, and objectives throughconstraints. The performance of this formulation is presented over two simulated test tracks on apareto front where the advantage on relaxing complete reference tracking becomes visible. Next,two new formulations each as a two stage optimization strategies (TSOS) are proposed, the mainobjective being to split the original formulation into two parts. One addressing energy optimalityand the other addressing reference tracking of total wheel torque and yaw moment request fulfilment.These formulations are then similarly investigated and presented in comparison with the originalformulation. In developing the formulations, an assumption about the loss models is made andthe problem size of the second stage quadratic program is significantly reduced. The problems areappropriately scaled and made mathematically robust to handle the constraints and inputs in theoperating range. As reference tracking for the vehicle is split into lateral and longitudinal torquerequests from the vehicle, this becomes a multi-objective optimization problem. To further studythe behaviour of these formulations, they are given constant inputs and simulated over a single timestep. The effect of changing hybridization level, i.e, the amount of electrical energy used comparedto fuel energy on the behaviour of these formulations is also explored. One of the effects of the twostage formulations was the confinement of solutions within a reasonable error for the majority ofchosen weights due to the energy considerations in the first stage. The proposed formulations wereable to generate results close but not equal to the original formulation on the pareto front. Anotherfinding was that due to the implementation of two actuators at the rear of the vehicle, a desired yawrate could be achieved at no additional energy cost because of regenerative and propulsive torquesgenerated respectively on either side of rear axle for torque vectoring. Furthermore with a dedicatedsolver, the TSOS could present an interesting alternative to enhance independent development invehicle dynamics control and energy management of the vehicle.För att minska miljöpåverkan av utsläpp från bilkörning är det ett ökat fokus på elektrifieringav bilar och förnybara bränslen. Detta examensarbete försöker att bidra till smartare användningav energiresurser under körning. Syftet är att bygga upp kunskap om effektiv energihantering ihybridfordon. En optimeringsbaserad reglerteknik används för att allokera drivmoment till olikaaktuatorer på drivlinan av ett hybridfordon och bestämma en balans mellan energieffektivitet ochmomenthantering för bättre körbarhet. Det studerade hybridfordonet har två elektriska motorermonterade på bakaxeln därtill har en förbränningsmotor och integrerad startmotor och generator påframaxeln. Momentallokeringsproblemet är ursprungligen löst med hjälp av en optimeringsstrategisom sker i ett steg som tar hänsyn till exempelvis systemets begränsningar och energiförluster.Denna formulering är förändrad för att skapa två olika formuleringar av en optimeringsstrategi somsker i två steg. Prestandan för de olika strategierna jämförs därefter på två olika simulerade testbanoroch visualiserades med hjälp av en paretofront. Syftet med att dela upp beräkningen i tvåsteg är för att göra det modulärt och förenkla gränssnittet mellan fordonsdynamik och fordonsenergihantering.Med denna uppdelning kan det ske oberoende forskning och utveckling inom bådaområdena. Det första steget hanterar energin och det andra steget hanterar hur väl systemet kanuppnå referensfördelningen av drivmoment och girmoment. De nya formuleringarna är baserade påen antagen förlustmodell och är omvandlade via skalning för att därefter jämföras med den ursprungligaformuleringen för att identifiera unika beteenden. En effekt av två-stegsformuleringen var attlösningarna begränsades inom ett rimligt felområde som en följd av energihanteringen i det förstasteget . Lösningarna från två-stegsformuleringen kom väldigt nära resultaten för den ursprungligaformuleringen. Två-stegsformuleringen kan vara ett bättre alternativ för att ha en modulär reglersystemsarkitekturom den kan utvecklas vidare med en dedikerad programvara i fordonets styrenhetsom använder ett lämpligt sätt för att räkna ut det optimeringsproblemet

Multi-Objective Optimization of Torque Distribution inHybrid Vehicles

Electrification is one of the mega-trends in the transportation and automotive industry today. Boththe alarming environmental conditions and the ever decreasing fuel reserves are driving the shifttowards hybrid, all electric and alternative fuel source vehicles. This thesis work is another smallstep towards studying, addressing and handling this issue while also laying the groundwork for developingand moving towards more efficient and commercially viable vehicles.This thesis work aims at investigating the trade-off offered by optimal control techniques betweenenergy consumption and reference tracking for torque allocation to the various actuators available topropel a hybrid electric vehicle. The particular vehicle under consideration has two electric motorsat the rear wheels and an internal combustion engine along with an integrator starter generatordriving the front wheels. The torque allocation problem is originally solved by proposing a one stageoptimization strategy (OSOS) that takes into account actuator limits, losses, and objectives throughconstraints. The performance of this formulation is presented over two simulated test tracks on apareto front where the advantage on relaxing complete reference tracking becomes visible. Next,two new formulations each as a two stage optimization strategies (TSOS) are proposed, the mainobjective being to split the original formulation into two parts. One addressing energy optimalityand the other addressing reference tracking of total wheel torque and yaw moment request fulfilment.These formulations are then similarly investigated and presented in comparison with the originalformulation. In developing the formulations, an assumption about the loss models is made andthe problem size of the second stage quadratic program is significantly reduced. The problems areappropriately scaled and made mathematically robust to handle the constraints and inputs in theoperating range. As reference tracking for the vehicle is split into lateral and longitudinal torquerequests from the vehicle, this becomes a multi-objective optimization problem. To further studythe behaviour of these formulations, they are given constant inputs and simulated over a single timestep. The effect of changing hybridization level, i.e, the amount of electrical energy used comparedto fuel energy on the behaviour of these formulations is also explored. One of the effects of the twostage formulations was the confinement of solutions within a reasonable error for the majority ofchosen weights due to the energy considerations in the first stage. The proposed formulations wereable to generate results close but not equal to the original formulation on the pareto front. Anotherfinding was that due to the implementation of two actuators at the rear of the vehicle, a desired yawrate could be achieved at no additional energy cost because of regenerative and propulsive torquesgenerated respectively on either side of rear axle for torque vectoring. Furthermore with a dedicatedsolver, the TSOS could present an interesting alternative to enhance independent development invehicle dynamics control and energy management of the vehicle.För att minska miljöpåverkan av utsläpp från bilkörning är det ett ökat fokus på elektrifieringav bilar och förnybara bränslen. Detta examensarbete försöker att bidra till smartare användningav energiresurser under körning. Syftet är att bygga upp kunskap om effektiv energihantering ihybridfordon. En optimeringsbaserad reglerteknik används för att allokera drivmoment till olikaaktuatorer på drivlinan av ett hybridfordon och bestämma en balans mellan energieffektivitet ochmomenthantering för bättre körbarhet. Det studerade hybridfordonet har två elektriska motorermonterade på bakaxeln därtill har en förbränningsmotor och integrerad startmotor och generator påframaxeln. Momentallokeringsproblemet är ursprungligen löst med hjälp av en optimeringsstrategisom sker i ett steg som tar hänsyn till exempelvis systemets begränsningar och energiförluster.Denna formulering är förändrad för att skapa två olika formuleringar av en optimeringsstrategi somsker i två steg. Prestandan för de olika strategierna jämförs därefter på två olika simulerade testbanoroch visualiserades med hjälp av en paretofront. Syftet med att dela upp beräkningen i tvåsteg är för att göra det modulärt och förenkla gränssnittet mellan fordonsdynamik och fordonsenergihantering.Med denna uppdelning kan det ske oberoende forskning och utveckling inom bådaområdena. Det första steget hanterar energin och det andra steget hanterar hur väl systemet kanuppnå referensfördelningen av drivmoment och girmoment. De nya formuleringarna är baserade påen antagen förlustmodell och är omvandlade via skalning för att därefter jämföras med den ursprungligaformuleringen för att identifiera unika beteenden. En effekt av två-stegsformuleringen var attlösningarna begränsades inom ett rimligt felområde som en följd av energihanteringen i det förstasteget . Lösningarna från två-stegsformuleringen kom väldigt nära resultaten för den ursprungligaformuleringen. Två-stegsformuleringen kan vara ett bättre alternativ för att ha en modulär reglersystemsarkitekturom den kan utvecklas vidare med en dedikerad programvara i fordonets styrenhetsom använder ett lämpligt sätt för att räkna ut det optimeringsproblemet

When CKD-MBD is not just CKD-MBD, a case of humoral hypercalcemia of malignancy in a dialysis patient

Patients on maintenance hemodialysis have dysregulations of calcium and phosphorus homeostasis which results in a plethora of mineral and bone pathologies. Management is typically focused on maintenance eucalcemia and limiting hyperphosphatemia while avoiding extremes of intact parathyroid hormone. Hypercalcemia in this setting is often iatrogenic. We present a case of humoral hypercalcemia of malignancy initially thought to be iatrogenic due to mineral bone management and discuss the overlap of management of hypercalcemia and management of mineral bone disease in end stage kidney disease. We highlight the relationship between malignancy and end stage kidney disease and the increased risk of hypercalcemia associated with malignancy

Successful treatment of COVID-19-associated collapsing glomerulopathy: 22 months of follow-up

The term COVAN (COVID-19-associated nephropathy) has been used to describe collapsing focal segmental glomerulosclerosis (FSGS) in individuals who have been infected with the SARS-CoV-2. This helps differentiate it from the majority of cases of acute kidney injury in COVID-19 patients, which are typically caused by acute tubular injury. The exact pathophysiology is unclear but is proposed to involve pro-inflammatory cytokines such as type 1 interferons, which are thought to increase expression of the gene in glomerular epithelial cells. This triggers a cascade of inflammatory events that cause damage to the epithelia and underlying podocytes. The treatment of COVAN is centered on general supportive measures including dietary sodium restriction, optimization of hyperlipidemia and hypertension, RAAS blockade, and diuresis for edema. There is limited data to support the use of glucocorticoids in COVAN; however, the mechanism of podocytopathy is similar to that in HIVAN (HIV-associated nephropathy), with high disease burden in those with gene mutation. Based on previous experience, treatment of HIVAN with glucocorticoids is beneficial and safe in selected patients. Here we present a case of COVAN which was successfully treated with glucocorticoids, and at 22-month follow-up patient remained in full remission (proteinuria \u3c 1,000 mg/g) with stable kidney function

SURGICAL OUTCOMES IN SECONDARY HYPOSPADIAS PATIENTS IN A TERTIARY CARE CENTRE – OVER A DECADE EXPERIENCE

Objective: The objective of this study is to analyze the surgical outcomes in secondary hypospadias patients over 10 years in a tertiary care center. Material & Methods: From January 2010 – December 2019, 68 patients with secondary hypospadias were managed in our department. The age at surgery, location of meatus at presentation, associated chordee, meatal stenosis, and fistula were noted. Techniques used for correction and postoperative complications with overall success rate were studied. Primary hypospadias cases (n=303) were excluded from this study. Results: Age varied from 6 months to 32 years (mean - 11.06 years).   The most common presentation was dehiscence of repair with resultant hypospadias (n=43) and their meatal position was distal 44.1% (n=30) followed by middle in 14.7 % (n=10) & proximal in 4.4% (n=3) patients after orthoplasty. Chordee was present in 67.64% (n=46) cases. (<30o in 50%, n=34; 30-600 in 14.7%, n=10; >60o in 2.9%, n=2).  Also, 17.6% (n=12) patients had urethrocutaneous fistula(UCF) and 19.1% (n=13) patients had meatal stenosis. Urethral closure was done using tubularized incise plate (TIP) alone in 4.4% (n=3) cases, TIP and spongioplasty in 48.5% (n=33) cases. The urethral plate was augmented (Snodgraft) in 26 cases (inner prepuce, n=5 and BMG, n=21). Urethral reconstruction was staged in 10.3% (n=7) cases. Meatoplasty was done in 19.1 (n=13) cases and fistula closure was done in 17.6% (n=12) cases. The success rate in secondary cases was 79.2% in our series. Fourteen patients required revision surgeries of which 7 had UCF (Fistula repair), meatal stenosis (n=1, meatoplasty), Glanular dehiscence (n=5, Glanuloplasty and Meatoplasty), stricture (n=1, urethroplasty). Conclusion: Hypospadias surgery in secondary cases is difficult owing to fibrosis, loss of local tissue, and difficult dissection. Glanular dehiscence was most common followed by fistula in our series. We also reported the effectiveness of buffering layers and urethral augmentation in secondary cases but without statistical significance.   Keywords: Secondary hypospadias, urethrocutaneous fistula, chordee. &nbsp