Delayed urologic cancer care in the COVID-19 pandemic: Patients' experiences.

OBJECTIVE: To understand experiences of patients with genitourinary cancer who experienced delayed cancer care due to the COVID-19 pandemic. METHODS: We conducted a mixed methods study with an explanatory sequential design. Qualitative findings are reported here. Patients with muscle invasive bladder, advanced prostate or kidney cancer were eligible. Participants were selected for interviews if they self-reported low (0-3/10) or high (6-10/10) levels of distress on a previous survey. Participants were interviewed about their experiences. Interviews were transcribed, coded and categorised using thematic data analysis methodology. RESULTS: Eighteen patients were interviewed. Seven had prostate cancer, six bladder cancer and five kidney cancer. Six themes were derived from the interviews: (1) arriving at cancer diagnosis was hard enough, (2) response to treatment delay, (3) labelling cancer surgery as elective, (4) fear of COVID-19 infection, (5) quality of patient-provider relationship and communication and (6) what could have been done differently. CONCLUSION: These findings offer insight into the concerns of patients with genitourinary cancers who experienced treatment delays due to COVID-19. This information can be applied to support patients with cancers more broadly, should treatment delays occur in the future.

A Parametric Analysis of Capillary Height in Single-Layer, Small-Scale Microfluidic Artificial Lungs.

Microfluidic artificial lungs (µALs) are being investigated for their ability to closely mimic the size scale and cellular environment of natural lungs. Researchers have developed µALs with small artificial capillary diameters (10-50 µm; to increase gas exchange efficiency) and with large capillary diameters (~100 µm; to simplify design and construction). However, no study has directly investigated the impact of capillary height on µAL properties. Here, we use Murray's law and the Hagen-Poiseuille equation to design single-layer, small-scale µALs with capillary heights between 10 and 100 µm. Each µAL contained two blood channel types: capillaries for gas exchange; and distribution channels for delivering blood to/from capillaries. Three designs with capillary heights of 30, 60, and 100 µm were chosen for further modeling, implementation and testing with blood. Flow simulations were used to validate and ensure equal pressures. Designs were fabricated using soft lithography. Gas exchange and pressure drop were tested using whole bovine blood. All three designs exhibited similar pressure drops and gas exchange; however, the µAL with 60 µm tall capillaries had a significantly higher wall shear rate (although physiologic), smaller priming volume and smaller total blood contacting surface area than the 30 and 100 µm designs. Future µAL designs may need to consider the impact of capillary height when optimizing performance.

Sex Differences in the Relation Between Supervision and Injury Risk Across Motor Development Stages: Transitioning From Infancy Into Toddlerhood.

RATIONALE: Addressing a notable gap in research on injuries during infancy, this longitudinal study examined sex differences in the relationship between parents' typical levels of supervision and infants' injuries across motor development stages. METHOD: Parents were recruited and completed biweekly phone calls about their infant's motor skills. Once the infant was able to sit up independently, then a home visit was scheduled. Applying a participant-event monitoring method, parents were taught to complete diary forms (injury, supervision), which they started doing once the child could move from their seated location on the floor in some way (e.g., roll, crawl). Recordings continued until a month after the child could walk independently. Data (injury, supervision) were averaged within each motor development stage (low, high), and associations across stages were examined. RESULTS: Model testing indicated that supervision level moderated the relation between injury rate across motor development stages, but the strength of this association varied by sex of the child. More intense supervision predicted lower injury rates for girls more so than for boys. CONCLUSIONS: Although the emergence of motor milestones has been associated with increased risk of injury during infancy, the current findings indicate that greater supervision can reduce this risk. However, supervision alone is not as effective to moderate injury risk for boys as it is for girls. Thus, for boys, additional strategies (e.g., hazard removal) may also be warranted to maximize reduction in their risk of injury as they acquire increasing motor skills.

Assessing and improving the biocompatibility of microfluidic artificial lungs.

Microfluidic artificial lungs (µALs) have the potential to improve the treatment and quality of life for patients with acute or chronic lung injury. In order to realize the full potential of this technology (including as a destination therapy), the biocompatibility of these devices needs to be improved to produce long-lasting devices that are safe for patient use with minimal or no systemic anticoagulation. Many studies exist which probe coagulation and thrombosis on polydimethyl siloxane (PDMS) surfaces, and many strategies have been explored to improve surface biocompatibility. As the field of µALs is young, there are few studies which investigate biocompatibility of functioning µALs; and even fewer which were performed in vivo. Here, we use both in vitro and in vivo models to investigate two strategies to improve µAL biocompatibility: 1) a hydrophilic surface coating (polyethylene glycol, PEG) to prevent surface fouling, and 2) the addition of nitric oxide (NO) to the sweep gas to inhibit platelet activation locally within the µAL. In this study, we challenge µALs with clottable blood or platelet-rich plasma (PRP) and monitor the resistance to blood flow over time. Device lifetime (the amount of time the µAL remains patent and unobstructed by clot) is used as the primary indicator of biocompatibility. This study is the first study to: 1) investigate the effect of NO release on biocompatibility in a microfluidic network; 2) combine a hydrophilic PEG coating with NO release to improve blood compatibility; and 3) perform extended in vivo biocompatibility testing of a µAL. We found that µALs challenged in vitro with PRP remained patent significantly longer when the sweep gas contained NO than without NO. In the in vivo rabbit model, neither approach alone (PEG coating nor NO sweep gas) significantly improved biocompatibility compared to controls (though with larger sample size significance may become apparent); while the combination of a PEG coating with NO sweep gas resulted in significant improvement of device lifetime. STATEMENT OF SIGNIFICANCE: The development of microfluidic artificial lungs (µALs) can potentially have a massive impact on the treatment of patients with acute and chronic lung impairments. Before these devices can be deployed clinically, the biocompatibility of µALs must be improved and more comprehensively understood. This work explores two strategies for improving biocompatibility, a hydrophilic surface coating (polyethylene glycol) for general surface passivation and the addition of nitric oxide (NO) to the sweep gas to quell platelet and leukocyte activation. These two strategies are investigated separately and as a combined device treatment. Devices are challenged with clottable blood using in vitro testing and in vivo testing in rabbits. This is the first study to our knowledge that allows statistical comparisons of biocompatible µALs in animals, a key step towards eventual clinical use.

Design Analysis and Optimization of a Single-Layer PDMS Microfluidic Artificial Lung.

OBJECTIVE: Microfluidic artificial lungs (µALs) are being researched for future clinical use due to the potential for increased gas exchange efficiency, small blood contacting surface area, small priming volume, and biomimetic blood flow paths. However, a current roadblock to clinical use is the need to stack hundreds to thousands of these small-scale µALs in parallel to reach clinically relevant blood flows. The need for so many layers not only increases the complexity and projected cost to manufacture a µAL, but also could result in devices which are cumbersome, and, therefore, not suitable for portable artificial lung systems. METHODS: Here, we describe the design analysis and optimization of a single-layer µAL that simultaneously calculates rated blood flow, blood contacting surface area, blood volume, pressure drop, and shear stress as a function of blood channel height using previously developed closed-form mathematical equations. A µAL designed using this procedure is then implemented and tested. RESULTS: The resulting device exhibits a rated flow of 17 mL/min and reduces the number of layers required for clinically relevant µAL devices by a factor of up to 32X compared to previous work. CONCLUSION: This procedure could significantly reduce manufacturing complexity as well as eliminate a barrier to the clinical application of these promising devices. SIGNIFICANCE: The described method results in the highest rated flow for any single-layer µAL to date.