Defining a Strategy for Laboratory Evaluation with Expectant Management of Preeclampsia.

OBJECTIVE: The objective of this study was to compare the frequency and timing of laboratory abnormalities and evaluate optimal laboratory testing strategies in women with preeclampsia (PE) undergoing expectant management. STUDY DESIGN: Retrospective cohort study of women with inpatient expectant management of PE at ≥23 weeks at a tertiary center from 2015 to 2018 was conducted. Women ineligible for expectant management or with less than two laboratory sets (platelets, aspartate aminotransferase, and serum creatinine) before the decision to deliver were excluded. Women were categorized as per the American College of Obstetricians and Gynecologists' definitions by initial diagnosis: PE without severe features, superimposed preeclampsia (SiPE) without severe features, and their forms with severe features. The frequency and timing of laboratory abnormalities were compared across the four PE categories. Kaplan-Meier curves modeled time to a laboratory abnormality (event) with censoring for delivery and were compared using log-rank tests. Logistic regression analysis modeled the development of a laboratory abnormality as a function of testing time intervals (days) for each PE type. Receiver operating characteristic curves and areas under the curve (AUC) were calculated; optimal cut points were determined using the Liu method. RESULTS: Among 636 women who met inclusion criteria, laboratory abnormalities were uncommon (6.3%). The median time to a laboratory abnormality among all women was ≤10 days, time being shortest in women with PE with severe features. Time to laboratory abnormality development did not differ significantly between the four PE groups (p = 0.36). Laboratory assessment intervals were most predictive for PE and SiPE with severe features (AUC = 0.87, AUC = 0.72). Optimal cutoffs were every 4 days for PE without severe features, 2 days for PE with severe features, 8 days for SiPE without severe features, and 3 days for SiPE with severe features. CONCLUSION: Most laboratory abnormalities in PE occur earlier and more frequently in those with severe features. Individual phenotypes should undergo serial evaluation based on this risk stratification. KEY POINTS: · Most laboratory abnormalities occur within 10 days of diagnosis.. · Laboratory abnormalities occur more often with severe features.. · Laboratory testing should occur according to disease severity..

Venous thromboembolism and adverse outcomes in highest thromboembolism risk patients compared with those at lower risk.

BACKGROUND: A risk-based institutional protocol for inpatient heparin-based venous thromboembolism prophylaxis in a general obstetrical population previously demonstrated a greater than 2-fold increase in wound hematomas with no change in the frequency of thromboembolism. OBJECTIVE: We sought to compare the rates of thromboembolism and bleeding outcomes in patients at the highest risk for thromboembolism (eg, those with a history of thromboembolism or thrombophilia who require anticoagulation prophylaxis or therapy throughout pregnancy) than low-risk patients. STUDY DESIGN: We performed a retrospective cohort study of all deliveries >20 weeks at a single center from 2013-2018. Patients were categorized as high-risk (received outpatient heparin-based prophylaxis or treatment) or low-risk (no outpatient anticoagulation). The primary outcome was newly diagnosed postpartum thromboembolism; the main secondary outcome was wound/perineal hematoma. The outcomes were compared between the high- and low-risk cohorts. Adjusted odds ratios (with 95% confidence intervals) were calculated with the low-risk group as reference. RESULTS: Of 24,303 total deliveries, 395 (1.7%) were high-risk and 23,905 (98.3%) were low-risk. Among the low-risk patients, 8.6% received anticoagulation prophylaxis in accordance with our risk-based inpatient thromboembolism prophylaxis protocol. High-risk patients were more likely to be older and have a higher body mass index, earlier delivery gestational age, medical comorbidities, and pregnancy complications, eg, preeclampsia. Despite outpatient antepartum anticoagulation, high-risk patients had an 11-fold increased risk of thromboembolism (adjusted odds ratio, 11.1 [4.7-26.2]) than low-risk patients. High-risk patients also had significantly more wound/perineal hematomas (adjusted odds ratio, 4.8 [2.7-8.4]), overall wound complications (adjusted odds ratio, 3.0 [2.0-4.4]), blood transfusions, intensive care unit admissions, maternal deaths, and longer maternal lengths of stay. CONCLUSION: Patients at the highest risk of obstetrical thromboembolism had an 11-fold increased risk of thromboembolism with a more moderate increase (∼5-fold) in postpartum wound and bleeding complications than low-risk patients. This more favorable risk or benefit profile supports current anticoagulation recommendations in high-risk patients.

Bioinspired elastomer composites with programmed mechanical and electrical anisotropies.

Concepts that draw inspiration from soft biological tissues have enabled significant advances in creating artificial materials for a range of applications, such as dry adhesives, tissue engineering, biointegrated electronics, artificial muscles, and soft robots. Many biological tissues, represented by muscles, exhibit directionally dependent mechanical and electrical properties. However, equipping synthetic materials with tissue-like mechanical and electrical anisotropies remains challenging. Here, we present the bioinspired concepts, design principles, numerical modeling, and experimental demonstrations of soft elastomer composites with programmed mechanical and electrical anisotropies, as well as their integrations with active functionalities. Mechanically assembled, 3D structures of polyimide serve as skeletons to offer anisotropic, nonlinear mechanical properties, and crumpled conductive surfaces provide anisotropic electrical properties, which can be used to construct bioelectronic devices. Finite element analyses quantitatively capture the key aspects that govern mechanical anisotropies of elastomer composites, providing a powerful design tool. Incorporation of 3D skeletons of thermally responsive polycaprolactone into elastomer composites allows development of an active artificial material that can mimic adaptive mechanical behaviors of skeleton muscles at relaxation and contraction states. Furthermore, the fabrication process of anisotropic elastomer composites is compatible with dielectric elastomer actuators, indicating potential applications in humanoid artificial muscles and soft robots.

Evaluation of a Risk-Stratified, Heparin-Based, Obstetric Thromboprophylaxis Protocol.

OBJECTIVE: To evaluate outcomes before and after implementation of a risk-stratified heparin-based obstetric thromboprophylaxis protocol. METHODS: We performed a retrospective cohort study of all patients who delivered at our tertiary care center from 2013 to 2018. Deliveries were categorized as preprotocol (2013-2015; no standardized heparin-based thromboprophylaxis) and postprotocol (2016-2018). Patients receiving outpatient anticoagulation for active venous thromboembolism (VTE) or high VTE risk were excluded. Coprimary effectiveness and safety outcomes were postpartum VTEs and wound hematomas, respectively, newly diagnosed after delivery and up to 6 weeks postpartum. Secondary outcomes were other wound or bleeding complications, including unplanned surgical procedures (eg, hysterectomies, wound explorations) and blood transfusions. Outcomes were compared between groups, and adjusted odds ratios (aORs) and 95% CIs were calculated using the preprotocol group as reference. RESULTS: Of 24,229 deliveries, 11,799 (49%) occurred preprotocol. Although patients were more likely to receive heparin-based prophylaxis postprotocol (15.6% vs 1.2%, P<.001), there was no difference in VTE frequency between groups (0.1% vs 0.1%, odds ratio 1.0, 95% CI 0.5-2.1). However, patients postprotocol experienced significantly more wound hematomas (0.7% vs 0.4%, aOR 2.34, 95% CI 1.54-3.57), unplanned surgical procedures (aOR 1.29, 95% CI 1.06-1.57), and blood transfusions (aOR 1.34, 95% CI 1.16-1.55). CONCLUSION: Risk-stratified heparin-based thromboprophylaxis in a general obstetric population was associated with increased wound and bleeding complications without a complementary decrease in postpartum VTE. Guidelines recommending this strategy should be reconsidered.

Paper-based wearable electronics.

Skin-interfaced wearable electronics can find a broad spectrum of applications in healthcare, human-machine interface, robotics, and others. The state-of-the-art wearable electronics usually suffer from costly and complex fabrication procedures and nonbiodegradable polymer substrates. Paper, comprising entangled micro- or nano-scale cellulose fibers, is compatible with scalable fabrication techniques and emerges as a sustainable, inexpensive, disposable, and biocompatible substrate for wearable electronics. Given various attractive properties (e.g., breathability, flexibility, biocompatibility, and biodegradability) and rich tunability of surface chemistry and porous structures, paper offers many exciting opportunities for wearable electronics. In this review, we first introduce the intriguing properties of paper-based wearable electronics and strategies for cellulose modifications to satisfy specific demands. We then overview the applications of paper-based devices in biosensing, energy storage and generation, optoelectronics, soft actuators, and several others. Finally, we discuss some challenges that need to be addressed before practical uses and wide implementation of paper-based wearable electronics.

Laser-induced graphene for bioelectronics and soft actuators.

Laser-assisted process can enable facile, mask-free, large-area, inexpensive, customizable, and miniaturized patterning of laser-induced porous graphene (LIG) on versatile carbonaceous substrates (e.g., polymers, wood, food, textiles) in a programmed manner at ambient conditions. Together with high tailorability of its porosity, morphology, composition, and electrical conductivity, LIG can find wide applications in emerging bioelectronics (e.g., biophysical and biochemical sensing) and soft robots (e.g., soft actuators). In this review paper, we first introduce the methods to make LIG on various carbonaceous substrates and then discuss its electrical, mechanical, and antibacterial properties and biocompatibility that are critical for applications in bioelectronics and soft robots. Next, we overview the recent studies of LIG-based biophysical (e.g., strain, pressure, temperature, hydration, humidity, electrophysiological) sensors and biochemical (e.g., gases, electrolytes, metabolites, pathogens, nucleic acids, immunology) sensors. The applications of LIG in flexible energy generators and photodetectors are also introduced. In addition, LIG-enabled soft actuators that can respond to chemicals, electricity, and light stimulus are overviewed. Finally, we briefly discuss the future challenges and opportunities of LIG fabrications and applications.

Impact of hydrogen peroxide on nitrite formation during UV disinfection.

One concern with UV disinfection of water is the production of nitrite when polychromatic UV sources are utilized. Based on previous work, it was hypothesized that a small addition of hydrogen peroxide (H(2)O(2)) may be useful in controlling nitrite during UV disinfection. However, it was found that H(2)O(2) addition (5 or 10mg/L) during polychromatic UV irradiation of drinking water at doses used for disinfection significantly increases the levels of nitrite produced relative to solutions without H(2)O(2). Enhancement rates ranged from approximately 15% to 40% depending upon pH and H(2)O(2) concentration; the relative increase in the NO(2)(-) yield was greater at pH 6.5 than at pH 8.3. The observed effects are tentatively ascribed to a combination of enhanced superoxide production and increased hydroxyl radical scavenging when H(2)O(2) is added. These results indicate that H(2)O(2) cannot be used to control nitrite production during UV disinfection and that enhanced nitrite formation will occur if H(2)O(2) is added during UV water treatment to achieve advanced oxidation of contaminants.