Search

Buttonhole cannulation, or buttonhole needling, is one of several methods of vascular access for dialysis patients. While this is a well-established technique, practices continue to vary across the UK. Catherine Fielding, Pat Cain, Paula Debling et al outline the new clinical practice recommendations that were introduced to help standardise and improve this vascular access technique.

Background Central venous stenosis and occlusion (CVO) is an increasing problem in the growing hemodialysis population. Sequelae include loss of access, loss of sites suitable for future venous access, and venous hypertension. Endoluminal techniques are often unsuitable to treat long-standing stenoses, and open surgery confers higher morbidity and is not appropriate in many patients. Case We present a case of long-standing central venous stenosis with an ipsilateral functioning fistula but with significant symptoms and signs of venous hypertension. The stenosis was not considered appropriate for endoluminal treatment, and the patient was considered to be at too high risk for open surgery. The Hemodialysis Reliable Outflow (HeRO) (Merit Medical Systems, UT) device was used to bypass the fistula to the superior vena cava via the contralateral internal jugular vein. Conclusions This case demonstrates the utility of the HeRO device in cases of long-standing CVO necessitating contralateral bypass. This technique confers the benefits of open surgery while minimizing the associated risks.

Scope & ObjectiveUnderbalanced coiled tubing drilling (UBCTD) is one of the keys to unlock the true potential of the tight and abrasive sandstone.The sandstone formation is mainly characterized by hard and abrasive sandstones interbedded with shale and siltstone. Typically, the sandstone formations are encountered at very deep depths. They are the most difficult sandstone formations to drill, with rock unconfined compressive strength (UCS) of up to 35,000 psi and internal friction angles ranging from 25 to 60 degrees. These conditions make it very difficult to drill and reach optimal lateral lengths. Additionally, it is very difficult to perform an openhole sidetrack (OHST) in such hard and abrasive formations, compared to more porous carbonates.Methods Procedures & ProcessThis paper will cover some of the key steps in optimizing underbalanced coiled tubing drilling in hard sandstones from different aspects such as drilling challenging profiles at high build rates, optimizing the rate of penetration (ROP), and also increasing formation contact by successfully performing OHST to deliver multiple laterals. The paper covers the following topics:Results, Observations, ConclusionsThe combination of technology and process has so far resulted in successful delivery of many sandstone wells with multiple laterals drilled on most of the wells, totalling more than 35000 ft in this hard and abrasive formation. The first-time success rate of openhole sidetracks was 96%. The average ROP and bit run lengths have also improved consistently.Novel/Additive InformationIt is expected that the recent improvements and consistency in delivering the sandstone UBCTD wells, will enable engineers to expand the horizon of UBCTD to several other fields, and tap the true potential of sandstone formations.

When fully suppressive regimens are not available, incompletely suppressive regimens also provide immunologic benefits. In this study, with stable background therapy, human immunodeficiency virus (HIV)-infected patients who were randomized to receive atazanavir or boosted atazanavir, compared with those who continued boosted protease inhibitor therapy, maintained similar virologic and immunologic control, resistance-mutation patterns, and replication capacities with reduced use of lipid-lowering medication.

Through tubing reentry drilling (3⅝") operations were first commenced in Saudi Arabia in 2008. Since then the application has proven to be an efficient and reservoir friendly method of reentry drilling. Old vertical and sometimes deviated candidate wells are screened and worked over bysetting a through tubing whipstock in the 4½", 5½" and 7" casings then exiting in a 3⅝" hole size. A curve section is then drilled at 20° to 35°/100 ft build up rate (BUR) and subsequently, lateral sections of 2,000 to 3,000 ft are drilled in the reservoir. Despite the good learning curve, certain technical challenges are limiting the operating envelope of 3⅝" through tubing re-entry drilling (TTRD). Some of these challenges are: surface setup and pressure deployment, inefficient tool face control, vibration, releasing a stuck bottom-hole assembly (BHA), etc. Other challenges related to drilling snadestone reservoirs. Keeping these challenges in mind, Saudi Aramco and Schlumberger (SLB) embarked on a project to develop a new drilling system, which would prevent and mitigate the risks highlighted above and allow safe application of 3⅝" TTRD to areas and fields where it was previously not practicable. This new drilling system was successfully deployed to the field in June 2012. The paper will cover some of the key features of the new drilling system, which were proven during the first job. Shorter BHA coupled with a customized tower, thereby eliminating the need for pressure deployment, greatly enhances safety and efficiency. Secondary release mechanism allowing for 90% recovery of BHA in case of a stuck bit.High precision and variable speed orienting system for more precise tool face control.A single ball valve in the upper BHA eliminates the need to bleed off the coil tubing (CT) pressure during deployment operations when drilling with nitrogen, saving time and money.Ultra-sensitive vibration sensors coupled with a 2-3 second update rate allows for quick identification of performance drilling motor (PDM) or turbine stalls.Coupled with high buildup rate turbodrills, the new drilling system is capable of drilling tight curves and laterals through compact and abrasive pre-Khuff sandstones at more than double the rate of penetration (ROP) previously possible with PDMs in a reduced number of trips. Wider deployment of this new drilling system would potentially unlock the true potential of the tight and abrasive pre-Khuff sandstone reservoir.

Raltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.To characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.In patients with viral load50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.Fourteen patients with a median CD4+ T-cell count of 420 cells/microL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.A switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.

Background. We sought to determine the safety of treatment interruption (TI) and to identify parameters that would define patients with human immunodeficiency virus (HIV) for whom TI is safer. Methods. AIDS Clinical Trials Group 5170 was a multicenter, 96-week-long, prospective study of HIV-infected patients receiving antiretroviral therapy (ART) who had CD4 + cell counts >350 cells/mm 3 and who underwent TI. Results. A total of 167 patients were enrolled. The median nadir in CD4 + cell count was 436 cells/mm 3 . The initial decrease (i.e., during the first 8 weeks) in CD4 + cell count after ART interruption was 20 cells/mm 3 /week; the subsequent decrease was 2.0 cells/mm 3 /week until week 96. Both the CD4+ cell count before enrollment and the increase in CD4+ cell count during ART predicted early decrease; later decrease was predicted by the level ofinterleukin-7 at enrollment. A Centers for Disease Control and Prevention (CDC) diagnosis of a category B or C event was made for 2 and 2 patients, respectively (all had CD4 + cell counts >350 cells/mm 3 ). At week 96, 17 patients had CD4 + cell counts ≤250 cells/mm 3 , and 46 patients had resumed ART; 5 patients died (unrelated to HIV or acquired immunodeficiency syndrome). In a multivariate analysis, a higher nadir in CD4 + cell count (>400 cells/mm 3 ), a lower HIV load (