Drainage Rate Research Articles

Abstract 4114994: Nursing Management Practice Variations related to Externalized Ventricular and Lumbar Drains

Introduction/Background: Nursing management of neurologic patients may include placement of externalized ventricular drains (EVDs) or lumbar drains (LDs) to monitor/drain cerebrospinal fluid (CSF), but knowledge and practice related to EVD management varies widely, despite a high potential for life-threatening complications. Limited data exists relative to the relationship between intracranial pressure (ICP) and CSF drainage. These gaps may undermine patient safety. Research Question: What are the nursing practices and perspectives regarding management of EVDs and LDs? Methods/Approach: A 16-question multiple-choice/text entry survey was distributed electronically to nurses and advanced practice nurses who were members of the American Association of Neuroscience Nurses. Data analysis included chi-square test for multiple choice responses, and qualitative data was analyzed using a six-step thematic analysis and an inductive approach. Results/Data: Of 219 participants, 42.8% reported roles as Neuroscience ICU nurses, and 39.2% managed an EVD at least 75% of the time. Neuro ICU nurses were most likely to have a patient with an EVD ( p =.002). Approximately 63% of respondents reported consulting with colleagues about EVDs nearly every time they cared for a patient with an EVD. Nurses reported a very high care burden, including re-leveling the transducer 4 or more times per shift (n=76), and re-zeroing every 8 hours (n=72) to assure accurate calibration. Of these 82.2% reported that they re-zeroed the EVD more often to obtain an accurate reading. Approximately 25% reported accidental over-drainage, some with negative outcomes. Many (79.3%) reported caring for patients with LDs, 47.4% to diagnose normal pressure hydrocephalus. The nursing care workload was described as 30-120 minutes each shift. Conclusion: A wide heterogeneity of nursing practices was revealed in EVD and LD management. No standardized nursing care practices have been adopted by nurses for the management of CSF. The complications of these practice variations have been shown to result in untoward patient outcomes. Increased patient morbidity and mortality are linked to catheter infection and over/under drainage of CSF and may be directly related nursing practice. This reveals critical need for improved, standardized care nursing practices in the management of EVDs and LDs, and an empiric understanding of the relationship between intracranial pressure and the volume and rate of CSF drainage.

Multi-scale reservoir response characteristics of coalbed methane development through stress relief via horizontal well cavity completion in tectonically deformed coals

China’s coalbed methane (CBM) resources hold significant potential. However, the widespread presence of soft and low-permeability tectonically deformed coal (TDC) presents a challenge to the efficient development of CBM. The development of CBM through stress relief via horizontal well cavity completion (HWCC) offers a promising innovative solution to this problem. To elucidate the multi-scale reservoir response characteristics of CBM development through stress relief via HWCC in TDCs, this article comprehensively employs particle discrete element and finite element numerical simulation methods, and carries out the numerical simulation studies of cyclic seepage at the specimen scale, HWCC at the coal seam scale, and CBM development at the coal seam group scale. The main findings are summarized as follows. Unlike the stress-compression specimens, which exhibited overall failure, the differential distribution of pressure gradients within the specimens during the gas seepage experiments resulted in the development of microcracks concentrated at the bottom of the specimens. With the escalation of coal body structural damage, the permeability stress compression coefficient during the elastic deformation stage shows an increasing trend. Upon entering the plastic deformation stage, the specimen’s permeability shifts from a decreasing to an increasing trend. Increasing the lower limit pressure ratio, upper limit pressure ratio, and cycle rate of gas injection pressure could accelerate the failure efficiency of the specimens. Increasing the lower limit pressure ratio has a more pronounced effect on the TDC specimens, while increasing the upper limit pressure ratio has a more significant impact on the primary undeformed and cataclastic coal specimens. In TDCs, the phenomenon of wellbore collapse and cavity expansion becomes more pronounced. The cavity volume tends to increase with the increase in the initial well diameter, in-situ stress, and alternating bottom-hole pressure differences. The HWCC could enhances reservoir permeability and production in both the cavity completed and adjacent coal seams. For two horizontal wells with cavity completions in the same layer, excessively close well spacing is unfavorable for fostering inter-well interference and reservoir pressure drop. When the HWCC is applied to thin coal seams, the enhancement of permeability and production is limited. Reasonable optimization of drainage rates could effectively mitigate the reservoir permeability velocity-sensitive damage. The research findings extend related theories and provide a robust reference for subsequent practical engineering applications.

Clean Intermittent Catheterisation via a Mitrofanoff is superior to long term Suprapubic Catheters for Bladder Drainage.

AimSome children require long-term drainage of the bladder but do not tolerate clean intermittent catheterisation (CIC) urethrally. We aimed to compare long term suprapubic catheter (SPC) drainage vs Mitrofanoff conduit (allowing CIC) by comparing the survival of the drainage methods and rates of urinary tract infection (UTI). MethodRetrospective review of a single surgeon’s experience (2007-2023). Data collection included diagnosis, age at procedures, date of surgery, date of most recent follow-up and date and reason for unplanned surgery. For SPCs, initial insertion of SPC and then conversion to a Foley catheter under GA was taken as normal (event free survival) and only further operations were counted as complication events. For Mitrofanoffs, any subsequent operation was counted as a complication.Data were given as a number (%) or median (interquartile range) as appropriate. Data analysed by Fisher exact and Mann-Whitney U-test. Kaplan Meier (KM) survival of drainage routes was compared, P<0.05 taken as significant. ResultsThere were 45 patients (n = 86 SPC episodes) compared to 108 patients (n = 110 Mitrofanoff procedures). Data were available in 73 SPC episodes and 109 Mitrofanoff episodes, including 3 redo procedures (one from another centre). There was no difference in gender (SPC group, 67% male vs. Mitrofanoff group, 77%; N.S.). There was no difference in age at procedure [7.5 (2.9 - 11.5) years vs 8.3 (5.9 - 11.4) years respectively; N.S.)KM comparison showed that Mitrofanoff have a better event-free survival than SPC (91% vs 52% at 1 year; 80% vs. 13% at 5 years; P<0.0001). Paired data showed a significant (86%) reduction in rate of UTI with conversion from SPC to Mitrofanoff drainage in 15 patients; SPC: 0.13 (0 - 0.46) UTIs/month vs subsequent Mitrofanoff: 0.02(0 - 0.08) UTI/month, P=0.04). ConclusionSPCs had a much higher rate of unplanned surgery than Mitrofanoffs, creating a considerable unplanned burden of care for families and clinical staff. For long-term bladder drainage CIC via a Mitrofanoff conduit should be considered in preference to SPC where urethral CIC is not possible.

Short-Term Bed Rest is not a Risk Factor for Venous Thromboembolism After Endoscopic Skull Base Surgery

IntroductionDeep venous thromboembolisms (DVT) increase morbidity in postoperative patients, and no current guidelines identify which patients undergoing endoscopic endonasal approach (EEA) to the skull base may be at increased risk. Postoperative care for these patients often includes a period of inactivity to prevent transient ICP shifts which may impact skull base reconstruction. We seek to characterize if postoperative bedrest puts EEA patients at increased risk of developing thromboembolic complications. MethodsRetrospective chart review of patients undergoing intradural surgery with primary skull base reconstruction for intraoperative CSF leak via EEA for any skull base pathology between July 2018 and May 2024 was performed yielding 221 patients who met inclusion criteria. Univariate and multivariable regression were performed with patient demographics, extent of approach, intraoperative leak flow rate, bedrest duration, presence and length of postoperative lumbar drainage (LD), and use of postoperative mechanical VT prophylaxis. ResultsThe mean age of included patients was 52.6 ± 16.8 years, 48% were male, and 3.6% of patients had DVTs. Age (OR 1.01, 95% CI 0.96-1.06, p=0.83), sex (OR 0.40, 95% CI 0.05-2.19, p=0.31), BMI (OR 0.98, 95% CI 0.87-1.07, p=0.74), extended approach (OR 0.80, 95% CI 0.13-4.36, p=0.80), CSF leak flow rate (OR 5.71, 95% CI 0.77-118.90, p=0.14), bedrest duration (OR 1.06, 95% CI 0.77-1.27, p=0.60), and presence of LD (OR 1.10, 95% CI 0.55-2.02, p=0.76) were not significant predictors of postoperative VTE incidence on multivariable analysis. ConclusionShort-term bedrest after EEA is not a risk factor for development of VTE in the immediate postoperative period.

On the non-linearity of rheological film condensation

Condensation of non-Newtonian fluids is a less explored research field but has tremendous potential in the industry. We propose a mathematical theory to model the behaviour of non-Newtonian film condensation on vertical surfaces. The simple theory can contribute to understanding the operation of many engineering appliances using motor oils, polymeric liquids, and fuels. The well-known power-law model approximates the viscosity of condensate. We vary the power-law index (n) within 0.8≤n≤1.2 to encompass the behaviour of shear-thinning, Newtonian and shear-thickening films, while the flow consistency index (μ0) remains constant throughout the study. Since the film flow is gravity-driven, stream-wise advection is expected to dominate over cross-stream advection. We, however, establish the subtle role of cross-stream advection within the thin condensate film. We have identified a thinner film, a lower condensate drainage rate and a greater average heat transfer coefficient (hm) as an influence of the cross-stream advection. An exclusion of cross-stream advection transforms temperature distribution across the film from non-linear to linear. The linear temperature distribution is unrealistic for Ja≥0.5. We illustrate approximately 5% error incurred for neglecting cross-stream advection in estimating hm at Ja=0.81 and n=0.8. The error increases with a further decrease in n values or an increase in the Ja. The exclusion of cross-stream advection affects the film-thickness and average heat transfer disproportionately in shear-thinning and shear-thickening regimes. Finally, we propose mathematical expressions to estimate heat transfer coefficient and Nusselt number, which would be helpful for field engineers.

Numerical Comparative Investigating of PEMFC with Novel Hybrid Zigzag Channels: Reaction, Transport and Drainage Enhancements

The impact of flow channel design on mass transport and drainage in proton exchange membrane fuel cells (PEMFCs) is significant, thereby influencing the reaction rate. Based on conventional wavy design, this study introduces two novel hybrid zigzag flow channels (asynchronous and synchronous) with both zigzag sidewalls and bottom wall, aiming in further improving mass and heat transfer, as well as drainage capacity to achieve better fuel cell performance. Numerical simulations demonstrate that the net power densities of both asynchronous and synchronous hybrid zigzag channels show a 28.7% and 44.4% improvement at low voltage, respectively. The implementation of the asynchronous hybrid zigzag flow channel has been observed to result in a notable reduction in pressure drop, amounting to 9.2%, while concurrently enhancing power output by 10.7% in comparison to a conventional zigzag channel. Additionally, the novel hybrid zigzag designs improve mass transfer efficiency at high current density and exhibits better temperature distribution uniformity. Moreover, the volume of fluid simulations illustrate that hybrid zigzag channels are highly effective in removing accumulated water, surpassing the straight channel with a drainage rate exceeding 54%, as well as a lower surface liquid coverage.

Enhanced rheology and firefighting performance of fluorine-free soft foams through the assembly of cellulose nanofibres and cellulose nanocrystals at the air–liquid interface

In this work, we developed soft and highly stable perfluorocarbon-free foams based on cellulose nanofibres (CNFs), cellulose nanocrystals (CNCs) and alkyl polyglycoside (APG). Neither the CNCs nor the CNFs can effectively stabilise the APG foam, which is reflected in the spontaneous degradation of the foam. Interestingly, blending these two nanocelluloses and foaming resulted in an ultrastable foam. The reflective optical interference technique was used to visualise liquid flow in the liquid film, and the results showed that the foam film with a thickness of only a few tens of nanometres gained excellent mechanical stability by tuning the assembly of CNCs and CNFs at the air–liquid interface. Moreover, the interfibril interactions at the Plateau borders reduce the bubble coarsening rate and drainage rate. In pool fire extinguishing tests, increasing the total concentration of CNCs and CNFs improved the foam stability, but increasing the viscosity led to a decrease in the foam spreading rate. Thus, a formulation with 0.4 % nanocellulose has poorer firefighting performance than a formulation with 0.15 % nanocellulose. When the ratios of CNCs and CNFs are properly controlled, the burnback performance of perfluorocarbon-free foam is better than that of state-of-the-art fluorinated AFFFs for n-heptane pool fires. The sustainability of the firefighting process is considerably improved by switching to the nonperfluorinated liquid foam developed in this work.

Utilisation of a post-Fontan management pathway reduces chest tube drainage and hospital readmission rates.

Complications following the Fontan procedure include prolonged pleural drainage and readmission for effusions. To address these complications, a post-Fontan management pathway was implemented with primary goals of reducing chest tube duration/reinsertion rates and decreasing hospital length of stay and readmissions. Fontan patients were identified by retrospective chart review (2017-2019) to obtain baseline data for chest tube duration/reinsertion rates, hospital length of stay, and readmission rates for effusion. A post-Fontan management pathway was implemented (2020-2021) utilising post-operative vasopressin, nasal cannula oxygen until chest tube removal, and discharge regimen of three times daily diuretics, sildenafil, and afterload reducing medications. Patients were followed to evaluate primary outcomes. The pre- and post-pathway groups were similar in single ventricle morphology, demographics, and pre-operative haemodynamics. Forty-three and 36 patients were included in the pre- and post-pathway cohorts, respectively. There were statistically significant reductions in chest tube duration (8 vs. 5 days, p ≤ 0.001), chest tube output on post-operative day 4 (20.4 vs. 9.9 mL/kg/day, p = 0.003), and hospital readmission rates for effusion (13[30%] vs. 3[8%], p = 0.02) compared to baseline. There was an absolute reduction in hospital length of stay (11 vs. 9.5 days, p = 0.052). When combining average cost savings for the Fontan hospitalisations, readmissions for effusion, and cardiac catheterisations within 6 months of Fontan completion, there was a $325,144 total cost savings for 36 patients following pathway implementation. Implementation of a post-Fontan management pathway resulted in significant reductions in chest tube duration and output, and readmission rates for effusion in the perioperative period.

Optimizing Methane Control in Composite Goaf Areas: Insights from Multisource Emission Analysis and Numerical Modeling in the Tongxin Coal Mine.

Coal mine methane poses a threat to both coal production and the well-being of workers. This study investigates the complex challenge of managing methane emissions from multiple sources in coal mines prone to gas. Coal mining creates multiple air leakage channels in the mine goaf, increasing the risk of gas explosions. Tracer SF6 measurements were employed to identify multiple air leakage channels. A comprehensive numerical model, incorporating multiple air leakage channels, was developed to simulate methane distribution in the goaf and upper corner. By adjusting the combination of gas drainage rate (U) and working face ventilation flux (Q), the concentration of methane at the upper corner is expected to be decrease, ensuring safe production at the Tongxin mine. A total of 48 simulation cases were conducted, determining that U = 1080 m3/min and Q = 2250 m3/min are recommended for the 8201 working face in the Tongxin coal mine. This combination provides not only an effective solution but also a cost-efficient one for methane control. The findings offer a new insight into effective methane control providing a foundation for improving mine safety.

Modeling of Drain Consolidation in the Quick Triaxial Test and Its Analytical Solution

ABSTRACTSand columns have been widely used to accelerate drainage and then improving the mechanical properties of soft soil foundations. The sand column has also been introduced into the triaxial test by researchers, in the center of the cylindrical specimen, to greatly accelerate drainage and consolidation process. The objective of this paper is to evaluate the consolidation properties of the triaxial cylindrical specimen considering the presence of a sand column, and then to propose a consolidation model that simulates the consolidation process of the triaxial test. The consolidation equations were derived considering the drainage of the specimen with a sand column composed of both vertical and double‐radial flows. Then the analytical solution of the model was obtained based on specific initial and boundary conditions. The comparison between the consolidation model and the laboratory tests yielded highly consistent. The case study demonstrated that the proposed consolidation model accurately simulates the evolution of average pore pressure and degree of consolidation in triaxial specimens containing a sand column. The studies on the consolidation parameters showed that there were different effects on the drainage rate for the diameter of specimen, the permeability coefficients of specimen and sand column, as well as the radius of the sand column.

Comparative analysis of clinical efficacy of stereotactic robot-guided puncture hematoma drainage and conventional puncture hematoma drainage in the treatment of intracerebral hemorrhage.

To compare and analyze the clinical effectiveness of conventional puncture hematoma drainage and stereotactic robot-guided puncture hematoma drainage in managing intracerebral hemorrhage. This is clinical comparative research. One hundred and twenty patients with the intracerebral hemorrhage who underwent puncture hematoma drainage in Baoding No.1 Central Hospital from March 2020 to May 2023 were included and were assigned into the control groups(n=60) and experimental groups(n=60) according to different treatment methods. The experimental group underwent stereotactic robot-guided puncture hematoma drainage, while the control group underwent conventional puncture hematoma drainage treatment. The duration and situation of surgery, levels of inflammatory factors, as well as preoperative and 1-week postoperative GCS scores and NIHSS scores were compared and analyzed between the two groups. In comparison with the control group, the experimental group exhibited considerably less surgical duration(p=0.00), higher amount of intraoperative blood drainage and hematoma clearance rate(p=0.00). The experimental group possessed a substantially more reduced incidence of complications(10%) in comparison with the control group(25%), with a statistically substantial distinction(p=0.03). After therapy, CRP, TNF-a, and IL-6 degrees were considerably more decreased (p=0.00) in the experimental group in comparison with the control group, while GCS grades were considerably more prominent and NIHSS grades were considerably more reduced (p=0.00). Stereotactic robot-guided puncture hematoma drainage is a dependable and safe operative method to treat patients who had intracerebral hemorrhage, resulting in various benefits such as short length of operation, less injury, less inflammatory reaction, high hematoma clear efficiency and satisfactory recovery of neurological function.

Preparation and characterization of high-stability gel foam for fracture plugging in reservoirs

A high-stability gel foam is successfully prepared by forming a gel structure in the liquid film using polymer and crosslinker. The foaming properties, gel characteristics, foam stability, and microstructure of the high-stability gel foam are systematically studied. Although increasing the viscosity of the liquid film reduces the foam volume, it significantly enhances the foam stability. Considering the foaming properties, gel characteristics, and economic benefits, the optimal formulation of the gel foam system is determined to be 0.8% surfactant, 0.3% hydroxypropyl guar gum (HPG), and 0.2% organic titanium crosslinker (ATC). Microstructural analysis revealed that, compared to water-based and polymer foams, gel foam has smaller bubble sizes, lower drainage rates, and slower coarsening rates. This improvement is mainly attributed to the increased viscosity and thickness of the liquid film after gel and the formation of a three-dimensional network structure. Water loss rate experiment shows that the foam stability is stronger when the liquid film has certain viscosity and elasticity to resist external disturbances. However, higher viscosity and film strength do not necessarily result in better foam stability. The final water loss rate of the gel foam after being placed at 100 °C for 10 h is 74.45%, much lower than that of other higher-strength gel foams (greater than 99%). Fracture plugging experiments demonstrated that the plugging rate of gel foam is high (80%), whereas water-based foam achieved only 37.5%. The gel foam can effectively plug fractures and expand the swept volume, showing great potential for improving oil reservoir recovery.

Soft bottles drain faster but glug slower

An inverted container of water drains with a periodic glugging process where bubbles of air enter through the bottom hole, thus replacing the exiting water. If the container is soft, its walls can flex with each glug. We examine the effect of container elasticity on the drainage process. Experiments are conducted to measure the drainage rate and the glug period as water drains out of a container through a bottom hole. The container compliance is varied by varying the diameter of a soft rubber membrane comprising the lid of the container. Increasing container compliance (i.e., making the container softer) is found to increase the drainage velocity, increase the glugging period, and increase the volume of each glug. Previously, Clanet and Searby (2004) modeled the glugging process as a spring-and-mass oscillator where the compressibility of air in the headspace acts as the spring. We adapt this model so that the membrane elasticity acts in series with the air compressibility. This adapted model qualitatively agrees with the observations but underpredicts the observed effect on the glug period.

Dynamic and empirical methods for field capacity estimation in fine textured soils with a coarse interlayer

Field capacity (FC) is an important soil hydraulic concept in soil science and irrigation management. It is generally determined from soil water content in a soil layer when soil profile reaches a steady pressure head or negligible drainage flux from an initially saturated soil. However, the proposed criteria are mainly tested for uniform soils and vary with soil textures. To quantify FC in layered soils, a Richards equation-based model was used to describe water flow in fine-textured soils with a coarse interlayer. With calibrated soil hydraulic parameters for loam and sand from infiltration measurements, drainage from saturation was simulated in the loam with a sand interlayer. A relative drainage rate (δ) was defined as a function of water storage and drainage flux to analyze soil water status at FC. Soil water content in the upper loam layer of layered profiles was improved compared with that in the uniform loam, which was negatively correlated with buried depth but positively correlated with thickness of the sand layer for a specified δ. Under different buried depths and thicknesses, soil water content decreased with the decline of δ and decreased rapidly as δ reduced to 1 % d−1. The drainage flux at δ = 1 % d−1 changed within a range of 0.056–0.26 cm d−1, and soil water content reached to 0.278–0.346 cm3 cm−3, which accounted for 70–87 % of the saturated water content of loam. Although the FC in the upper fine-textured soil layer varied for different buried depths and thicknesses of coarse interlayer, the proposed dynamic method is reliable and universal to estimate the FC in the above layered soils at δ = 1 % d−1. An empirical equation was also developed to calculate the FC in fine-textured soils with different buried depths and thicknesses of a coarse interlayer based on the critical δ value.

Patterns of forearm lymphatic drainage to the epitrochlear lymph nodes in 1400 cutaneous melanoma patients.

Variations of hand and forearm lymphatic drainage to upper-arm lymphatic pathways may impact the route of melanoma metastasis. This study compared rates of lymphatic drainage to epitrochlear nodes between anatomic divisions of the hand and forearm to determine whether the anatomic distribution of hand and forearm melanomas affects the likelihood of drainage to epitrochlear lymph nodes. Using a single-institution lymphoscintigraphy database, we identified all patients with cutaneous melanoma on the hand and forearm. A body-map two-dimensional coordinate system was used to classify cutaneous melanoma sites between radial-ulnar and dorsal-volar divisions. Sentinel lymph nodes (SLNs) visualized on lymphoscintigraphy were recorded. Proportions of patients with epitrochlear SLNs were compared between anatomic divisions using χ2 analysis. Of 3628 upper extremity cutaneous melanoma patients who underwent lymphatic mapping with lymphoscintigraphy, 1400 met inclusion criteria. Twenty-one percent of patients demonstrated epitrochlear SLNs. Epitrochlear SLNs were observed in 27% of dorsal forearm melanomas and 15% of volar forearm melanomas (p < 0.001). Epitrochlear SLNs were observed in 31% of ulnar forearm melanomas and 17% of radial forearm melanomas (p < 0.001). Higher proportions of dorsal and ulnar forearm melanomas have epitrochlear SLNs. Metastasis to epitrochlear SLNs may be more likely from melanomas in these respective forearm regions.

The Success Rate Is Lower but Completion Rate of Laparoscopic Cholecystectomy Is higher in Endoscopic Transpapillary Gallbladder Drainage than Percutaneous Gallbladder Drainage for Acute Cholecystitis.

We investigated the success and complication rates of endoscopic transpapillary gallbladder drainage (ETGBD) and percutaneous transhepatic gallbladder drainage (PTGBD) and the outcomes of subsequent cholecystectomy for acute cholecystitis. Patients (N=178) who underwent cholecystectomy after ETGBD or PTGBD were retrospectively assessed. ETGBD was successful in 47 (85.5%) of 55 procedures, whereas PTGBD was successful in 123 (100%) of 123 sessions ( P <0.001). Complications related to ETGBD and PTGBD occurred in 6 (12.8%) of 47 and 16 (13.0%) of 123 patients, respectively ( P =0.97). After propensity matching, 43 patients from each group were selected. Median time from drainage to cholecystectomy was 48 (14 to 560) days with ETGBD and 35 (1 to 90) days with PTGBD ( P =0.004). Laparoscopy was selected more often in the ETGBD group (97.7%) than in the PTGBD group (79.1%) ( P =0.007), and conversion from laparoscopy to open cholecystectomy was more common with PTGBD (41.2%) than with ETGBD (7.1%) ( P <0.001). Mean operation time was significantly shorter with ETGBD (135.8±66.7min) than with PTGBD (195.8±62.2min) ( P <0.001). The incidence of Clavien-Dindo grade ≥III postoperative complications was 9.3% with ETGBD and 11.6% with PTGBD ( P =0.99). The success rate is lower but completion of laparoscopic cholecystectomy is more in endoscopic gallbladder drainage than percutaneous gallbladder drainage for acute cholecystitis.

The clinical value of carbon nanoparticles in sentinel lymph node biopsy for early vulvar cancer

ObjectiveCarbon nanoparticle (CNP)-guided sentinel lymph node biopsy (SLNB) has been extensively adopted as a cost-effective and highly efficient method for tracing malignant tumors except for those associated with vulvar cancer. The current study aimed to validate the feasibility and efficacy of CNPs in tracking sentinel lymph nodes (SLNs) in patients with early vulvar cancer. MethodsWe retrospectively reviewed patients with vulvar cancer at our institution from January 2016 to April 2022 who were pathologically diagnosed and underwent SLNB or inguinofemoral lymphadenectomy (IFLND). CNPs were the only lymphatic tracer used in SLNB. Patient demographics, perioperative outcomes and follow-up results, including overall survival (OS) and progression-free survival (PFS), were compared between the SLNB and IFLND groups. ResultsData from 52 patients were collected and investigated. Forty groins of 22 patients who underwent SLNB with CNP tracing were included. Black-stained SLNs were detected in 32 groins of 19 patients, and the rates of CNP detection by patient and by groin were 86.4 % and 80 %, respectively. Patients who underwent SLNB had better perioperative outcomes than those who underwent IFLND in certain aspects (groin drainage rate: 41.2 % and 80 %, respectively, p < 0.05; daily drainage volume (ml): 12.49 and 36.4, respectively, p < 0.05; and inguinal wound healing rate: 100 % and 80 %, respectively, p < 0.05). The results of survival analysis indicated similar prognoses for node-negative patients who underwent CNP-guided SLNB or IFLND. ConclusionsSentinel lymph node mapping with CNPs in vulvar cancer is feasible and demonstrates considerable biosecurity. With a satisfactory SLN detection rate achieved expediently, CNPs are a promising lymphatic tracer worthy of further utilization in vulvar cancer and could be an alternative option to canonical tracers.

Detecting Atypical Sentinel Lymph Nodes in Early-Stage Cervical Cancer Using a Standardized Technique with a Hybrid Tracer.

Since October 2018, lymph node status has become part of the FIGO staging, given that it is one of the most important prognostic factors among women with CC. The aim was to determine the rate of atypical lymphatic drainage in patients with clinical early-stage cervical cancer using a hybrid tracer (ICG-99mTc nanocolloid). A prospective, observational, single-centre study conducted at Son Espases University Hospital between January 2019 and October 2023. Patients with clinical early-stage CC who underwent SLN mapping were included. External iliac and obturator nodes were defined as common locations. Para-aortic, common iliac, presacral, internal iliac, and parametrial nodes were defined as atypical locations. Thirty-nine cases of CC were included. The overall SLN detection rate was 97.4%, with 89.5% bilaterally. Positive nodes were found in 21.1% of patients. Atypical lymphatic drainage was present in 8 out of 38 (21.1%) patients. Of all the SLNs biopsied (146), 10.3% corresponded to an atypical zone. SLN in the atypical area had a higher proportion of metastasis than the usual area (37.5% vs. 16.7%; p = 0.327). SLN biopsy can detect unusual drainage in a significant proportion of patients. Atypical lymph nodes have a higher percentage of metastasis, which consequently improves staging and tailoring therapy. SLN mapping performed via a standardized surgical technique using a hybrid tracer (ICG-99mTc) could help in the identification of the "true SLN".

Complications of Venous Thromboembolism Chemoprophylaxis in Lumbar Laminectomy With and Without Fusion.

The benefit of chemoprophylaxis (CPX) agents in preventing venous thromboembolism must be weighed against potential risks. Current literature regarding the efficacy of CPX after laminectomies with or without fusion is limited, with no clear consensus to inform guidelines. This study evaluated the association between CPX and surgical complications after lumbar laminectomy with and without fusion. Retrospective study of patients at a single large academic institution. The medical records of patients who underwent lumbar laminectomies with or without lumbar fusion from 2018 to 2020 were reviewed for demographics, surgical characteristics, CPX agents, postoperative complications, epidural hematomas, and wound drainage. Patients receiving CPX (n = 316) were compared with patients not receiving CPX (n = 316) via t test following propensity score matching, and patients on CPX were further stratified by fusion status. The CPX group had higher body mass index and American Society of Anesthesiologists grades. Rates of venous thromboembolism, epidural hematomas, infections, postoperative incision and drainage, transfusions, wound dehiscence, and reoperation were not associated with CPX. Moist dressings were more frequent, and average days of drain duration were longer with CPX. Overall postoperative complication rate and length of stay (LOS) were greater with CPX. The fusion subgroup had a lower Charlson Comorbidity Index, had a lower American Society of Anesthesiologists grade, was younger, had more women, and underwent more minimally invasive laminectomies. While estimated blood loss, operative times, and LOS were significantly greater in the fusion group, there was no difference in rate of intraoperative and postoperative complications. CPX after lumbar laminectomies with or without fusion was not associated with increased rates of epidural hematomas, wound complications, or reoperation. Patients receiving CPX had more postoperative cardiac complications, but it is possible that surgeons were more likely to prescribe CPX for higher-risk patients. They also had higher rates of ileus and moist dressings, greater LOS, and longer length of drain duration. Patients who underwent lumbar laminectomy with fusion on CPX tended to be lower risk yet incurred greater blood loss, operative times, LOS, cardiac complications, and hematomas/seromas than patients not undergoing fusion. This retrospective study compared surgical complications of lumbar laminectomies in patients who received chemoprophylaxis vs patients who did not. Chemoprophylaxis was not associated with increased rates of epidural hematomas, wound complications, or reoperation, but it was associated with higher rates of postoperative cardiac complications and ileus.

Study on the Distribution Law of External Water Pressure with Limited Discharge during Shield Construction of Soft Rock Tunnel in Western Henan Province

When shield tunneling is carried out in poor geological areas with high water head and low strength, there is a great construction risk, and the external water pressure is one of the key factors affecting the stability and safety of the tunnel during shield tunneling. Taking the Yinguruxin tunnel of Xin’an County as the engineering background, the geological conditions and water-bearing characteristics of the water-rich area in the tunnel excavation path are analyzed by means of drilling and high-density electrical method, and the pumping test is used to evaluate the groundwater linkage in the water-rich area. The 2022 version of Midas GTS NX is used to study the distribution characteristics of external water pressure during tunnel excavation in fault zones, and the influence of different drainage rates on the external water pressure of the tunnel is analyzed. The results show that the rock mass in the unfavorable geological section of the tunnel excavation is broken and rich in water, but the complexity of the stratum leads to uneven water richness in the axis direction of the tunnel. The drainage rate is the key to affecting the external water pressure of the lining. The drainage rate is the key to affecting the external water pressure of the tunnel. The correct drainage rate is an effective measure to reduce the external water pressure of the tunnel. The internal and external water pressure of the tunnel decreases with the increase of the drainage rate. When the drainage rate reaches 66.67% of the water inflow, the external water pressure of the tunnel can be reduced to 0.3 MPa to ensure the safety of the earth pressure balance shield machine in the tunneling process. The conclusion provides a useful reference for the high water pressure control of the tunnel shield tunneling process.