Comparison of three purse-string suture techniques for prevention of anal leakage during surgery

OBJECTIVE To compare 3 anal purse-string suture techniques for resistance to leakage and to identify the suture technique requiring the fewest tissue bites to create a consistent leak-proof orifice closure. ANIMALS 18 large-breed canine cadavers. PROCEDURES 3 purse-string suture techniques (3 bites with 0.5 cm between bites [technique A], 5 bites with 0.5 cm between bites [technique B], and 3 bites with 1.0 cm between bites [technique C]) were evaluated. Each technique involved 2-0 monofilament nylon suture that was placed in the cutaneous tissue around the anus and knotted with 6 square throws. Standardized 2.0-cm-diameter circular templates with the designated bite number and spacing indicated were used for suture placement. Leak-pressure testing was performed, and the pressure at which saline was first observed leaking from the anus was recorded. The median and interquartile (25th to 75th percentile) range (IQR) were compared among 3 techniques. RESULTS Median leak pressure for technique A (101 mm Hg; IQR, 35 to 131.3 mm Hg) was significantly greater than that for technique C (19 mm Hg; IQR, 14.3 to 25.3 mm Hg). Median pressure did not differ between techniques A and B (50 mm Hg; IQR, 32.5 to 65 mm Hg) or between techniques B and C. CLINICAL RELEVANCE Placement of an anal purse-string suture prevented leakage at physiologic colonic and rectal pressures, regardless of technique. Placement of 3 bites 0.5 cm apart (technique A) is recommended because it used the fewest number of bites and had the highest resistance to leakage.

A Success Story of Critical Data Gathering During the Development Phase of Extreme ERD Well Drilling

This paper discusses a holistic combination of advanced formation evaluation techniques with pressure testing and reservoir navigation services to mitigate uncertainty related challenges in real time and successfully drill & place ERD laterals targeting Jurassic carbonate reservoirs. A meticulously planned approach to navigate the well trajectory by tracking the desired properties, informed decision-making while drilling and accurate data acquisition for aiding appropriate selection and placement in-flow control device (ICD) in lower completion design and future reservoir management contributed to the success of these complex wells in carbonate reservoirs. The first well in this study, involved drilling and evaluating a long lateral section as single oil producer targeting a carbonate reservoir. While no tar presence was expected, a combination of density, neutron porosity and nuclear magnetic resonance (NMR) logs while drilling resulted in identifying a deficit NMR porosity when compared to density porosity. Deployment of a formation pressure testing while drilling (FPWD) tool enabled measurement of the formation mobility and validate the presence of a tar. Using the same combination of measurements in the subsequent wells for delineating the tar enabled accurate planning of injection wells on the periphery of the field. Approximately 3 days were saved compared to the first well where the drill string had to be POOH to run-in with FPWD service. Hence, having FPWD tool in the same string helped in confirming the formation mobility in real time to call for critical decision making like changing the well trajectory or calling an early TD. Across all the wells drilled in this field, the formation pressure, mobility and porosity measurements provided valuable input for optimum ICD placement and design. Successful identification of unexpected tar resulted in substantial rig time savings, accurate planning of asset utilization and added confidence in design and placement of lower completions by utilizing LWD data. Benefits of integrated data and services combination became clear for applications involving advanced reservoir characterization and enhanced well placement in complex carbonate reservoirs. From the offset wells, a tar was seen in deeper formations but the integration of LWD NMR and mobility data from this well confirmed the presence of a tar within the zone of interest. The study established a cost-effective workflow for mitigating uncertainties related to tar encountered while drilling extreme ERD laterals in an offshore environment where any lost time results in significant increase in expenditures during the development phase. A systematic approach to tackle these uncertainties along with acquisition of critical data for the design & placement of completion results in optimum production from the reserves.

Lessons Learnt from a Successful Sampling While Drilling Campaign Delivering Formation Oil Samples and Saturation Pressure Measurements in High H2S Carbonates

As island development strategies gain focus for capitalizing deep offshore assets, limitations like fixed slot location bring about the need for drilling extended reach (ERD) wells with multiple drain holes and complex well geometry to maximize the reservoir coverage for increased production. Pressure testing and reservoir fluid sampling operations require long stationary time and pose a risk of differential sticking. Deploying a pressure testing and fluid sampling tool into the drilling bottom-hole assembly (BHA) helps in maintaining well control through continuous circulation and providing measures to retrieve the tool by rotation and jarring in case of pipe sticking. This paper presents the successful deployment of sampling while drilling tools in three ERD wells drilled using water based and oil based muds to acquire representative formation oil samples from a high H2S carbonate reservoir. The formation oil samples were collected immediately after drilling the well to the target depth for limiting the invasion to collect clean samples in shorter pump-out volume and time. After securing the samples, a phase separation test was performed by fluid expansion in a closed chamber to measure the saturation pressure of the oil. A 30-min long pressure build up was also performed for pressure transient analysis to estimate permeability. Formation fluid samples were collected, while pulling out the drilling BHA, within 12-48 hours of drilling the well by pumping out 100-170 liters of fluid from the formation in 4-6 hours. During clean up, absorbance spectroscopy identifies the fluid phases – gas, oil and water. Prominent trends observed in compressibility, mobility, sound slowness and refractive index measurements add confidence to the fluid identification and provide accurate contamination measurements. Single-phase tanks charged with nitrogen were used to assure quality samples for PVT analysis. The sample tanks are made of MP35N alloy and the flow lines are made of titanium that are both H2S resistant and non-scavenging materials and hence, a separate coat of non-scavenging material was not required. In highly deviated wells, sampling while drilling technology can close the gaps of the conventional wireline operation on pipe conveyed logging in addition to saving 5-days of rig time by eliminating the need for conditioning trips, a dedicated run for pressure testing and sampling and minimizing the risk of stuck pipe and well control incidents The results from downhole fluid analysis and PVT lab are compared in this paper. Going forward, this technology can eliminate the requirement of a pilot hole for pressure testing & sampling by enabling sampling in complex well geometries in landing sections and ERD wells. The paper concludes with discussions on suggested improvements in the tool design and capability and recommendations on best practices to align with the lessons learnt in this sampling while drilling campaign.

Clinical foot measurements as a proxy for plantar pressure testing in people with diabetes

Background High plantar pressures are associated with increased foot ulcer risk in people with diabetes. Identification of high plantar pressures in people with diabetes is clinically challenging due to time and cost constraints of plantar pressure testing. Factors affecting foot biomechanics, including reduced joint range of motion and foot deformity, are implicated in the development of high plantar pressures and may provide a method to clinically identify those at risk of pressure related complications. The aim of this study was to investigate the contribution of joint range of motion and foot deformity measures on plantar pressures in a community dwelling group with diabetes. Methods Barefoot (Tekscan HR Mat™) and in-shoe (Novel Pedar-X®) plantar pressure variables, weight bearing ankle dorsiflexion, hallux range of motion, lesser toe deformities and hallux abductus (HAV) scale were assessed in 136 adults with diabetes (52.2% male; mean age 68.4 years). Multivariate multiple linear regression was used to assess the effect of the four biomechanical factors plus neuropathy and body mass index on plantar pressure variables. Non-parametric bootstrapping was employed to determine the difference in plantar pressure variables for participants with two or more foot biomechanical pathologies compared to those with less than two pathologies. Results Almost one third (32%) of the cohort had two or more foot biomechanical pathologies. Participants with two or more foot biomechanical pathologies displayed significant increases in all barefoot plantar pressure regions (except forefoot), compared to those with less than two pathologies. No significant changes were found for the in-shoe plantar pressure variables. The regression model explains between 9.9% (95%CI: 8.4 to 11.4%) and 29.6% (95% CI: 28.2 to 31%), and between 2.5% (1.0 to 4.0%) and 43.8% (95% CI: 42.5–44.9%), of the variance in the barefoot and in-shoe plantar pressure variables respectively. Conclusions Participants presenting with two or more factors affecting foot biomechanics displayed higher peak pressures and pressure time integrals in all foot regions compared to those with less than two factors. The tests used in this study could help clinicians detect elevated plantar pressures in people with diabetes and present an opportunity for early preventative interventions.

Positive Pressure Testing Booths Development and Deployment in Response to the COVID-19 Outbreak

The COVID-19 pandemic left an unprecedented impact on the general public health, resulting in hundreds of thousands of deaths in the US alone. Nationwide testing plans were initiated, with drive-through being the currently dominant testing approach, which, however, exhausts personal protective equipment supplies, and is unfriendly to individuals not owning a vehicle. Walk-up positive pressure testing booths are a safe alternative, whereby a health care provider situated on the inside of an enclosed and positively pressurized booth swabs a patient on the outside through chemical resistant gloves. The booths, however, are too prohibitively priced on the market to allow for nationwide deployment. To mitigate this, we present in this paper a safe, accessible, mobile and affordable design of positive-pressure COVID-19 testing booths. The booths have successfully passed the CDC and HICPAC pressure, air exchange, and air quality requirements for positive-pressure rooms, following the guidelines for environmental infection control in health care facilities. The booths are manufactured using primarily off-the-shelf components from US vendors with minimized customization, and the final bill of materials does not surpass USD 3,900. Since August 2019, five booths were deployed and used at the Johns Hopkins University School of Nursing, Baltimore City Health Department, and two community health centers in Baltimore. No health care provider was infected when using our booths, which have shown to facilitate walk-up testing with decreased PPE consumption, reduced risk of infection, and enhanced accessibility to lower-income communities and non-drivers.

Leak Testing

While the exercise of pressurizing a piping system and checking for leaks is sometimes called pressure testing, the Code refers to it as leak testing. The main purpose of the test is to demonstrate that the piping can confine fluid without leaking. When the piping is leak tested at pressures above the design pressure, the test also demonstrates that the piping is strong enough to withstand the pressure. For large bore piping where the pipe wall thickness is close to the minimum required by the Code, being strong enough to withstand the pressure is an important test. For small bore piping that typically has a significant amount of extra pipe wall thickness, being strong enough is not in question. Making sure that the piping is leak free is important for all piping systems.