Design and performance testing of a novel emergency ventilator for in-hospital use.

BACKGROUND: The rapidly evolving COVID-19 pandemic has led to increased use of critical care resources, particularly mechanical ventilators. Amidst growing concerns that the health care system could face a shortage of ventilators in the future, there is a need for an affordable, simple, easy to use, emergency stockpile ventilator. METHODS: Our team of engineers and clinicians designed and tested an emergency ventilator that uses a single limb portable ventilator circuit. The circuit is controlled by a pneumatic signal with electronic microcontroller input, using air and oxygen sources found in standard patient rooms. Ventilator performance was assessed using an IngMar ASL 5000 breathing simulator, and it was compared with a commercially available mechanical ventilator. RESULTS: The emergency ventilator provides volume control mode, intermittent mandatory ventilation and continuous positive airway pressure. It can generate tidal volumes between 300 and 800 mL with <10% error, with pressure, volume, and waveforms substantially equivalent to existing commercial ventilators. CONCLUSIONS: We describe a cost effective, safe, and easy to use ventilator that can be rapidly manufactured to address ventilator shortages in a pandemic setting. It meets basic clinical needs and can be provided for emergency use in cases requiring mechanical ventilation because of complications due to respiratory failure from infectious diseases.

Neighborhood Socioeconomic Disadvantage Associated With Increased 90-Day Mortality Following Radical Cystectomy.

OBJECTIVE: To examine relationships between neighborhood socioeconomic disadvantage and outcomes following radical cystectomy (RC). MATERIALS AND METHODS: A retrospective single institution study of consecutive RCs performed for bladder cancer between 2011 and 2019. Major complications, mortality and survival outcomes were compared using Cochran-Armitage or Kruskal-Wallis tests. Cox proportional hazards models were used for time-to-event analyses. RESULTS: A total of 906 patients were included in analysis. Overall 90-day mortality was 2.98% (27/906). Ninety-day mortality rates observed in the least (first) and most (fourth) disadvantaged ADI quartiles were 0% (0/115) and 6.5% (12/185), respectively. Patients from the fourth quartile demonstrated worse overall survival and recurrence free survival than those in the first quartile. ADI quartile was positively associated with muscle invasive (P = .0006) and node positive (P = .042) disease. ADI percentile was an independent predictor for 90-day mortality (adjusted OR: 1.022, CI: 1.004-1.04, P = .015). CONCLUSION: Higher rates of mortality and worse oncologic outcomes were observed for patients residing in the most disadvantaged quartile. ADI was associated with higher likelihood of 90-day mortality and may therefore be useful in patient counseling, risk stratification, and post-discharge management.

Comparison of Major Complications at 30 and 90 Days Following Radical Cystectomy.

OBJECTIVES: To better understand the time-course in which major complications occur after radical cystectomy and to describe associations with complications at 30 and 90 days. METHODS: A database of radical cystectomy cases was queried for preoperative, perioperative, and postoperative data. Follow-up extended to 90 days postsurgery and included major complications (Clavien III-V). Early (30-day) and late (90-day) complication rates were compared via McNemar's test, and patient characteristics were compared across complication time groups by one-way ANOVA or Fisher's exact tests. Multinomial logistic regression was used to explore associations between patient characteristics and complication timing. RESULTS: Of 969 patients undergoing radical cystectomy, 210/969 (21.7%) experienced a complication within 90 days. The rate of major complication significantly differed at 30 and 90 days (14.4% [conflict of interest (CI): 12.4%-16.9%] vs 21.7% [CI: 19.2%-24.4%] respectively, P ≤.0001). Chronic obstructive pulmonary disease (COPD) (P = .03), Charlson Comorbidity Index (P = .02), and Indiana pouch diversion (P = .002) were significant predictors of early complication. Diabetes was the strongest predictor for late complication (OR: 2.42; P = 0.01). Diabetes was also a significant predictor for late genitourinary complications (OR 3.39; P = .01), and smoking history was a significant predictor for late infectious complications (OR 3.61; P = .01). CONCLUSION: We identified a significant number of complications occurring after 30 days postcystectomy, including the majority of deaths and genitourinary complications. These findings suggest that assessment of complications exclusively at 30 days would fail to capture a large proportion of major complications and deaths. Understanding the time-course of complications postcystectomy will serve to better inform design of future outcome studies.

Uretero-Enteric Anastomotic Stricture Following Radical Cystectomy: A Comparison of Open, Robotic Extracorporeal, and Robotic Intracorporeal Approaches.

OBJECTIVES: To compare the incidence of benign uretero-enteric anastomotic strictures between open cystectomy, robotic cystectomy with extracorporeal urinary diversion, and robotic cystectomy with intracorporeal urinary diversion. The effect of surgeon learning curve on stricture incidence following intracorporeal diversion was investigated as a secondary outcome. PATIENTS AND METHODS: Patients who underwent radical cystectomy at an academic hospital between 2011 and 2018 were retrospectively reviewed. The primary outcome, incidence of anastomotic stricture over time, was assessed by a multivariable Cox proportional hazards regression. A Cox regression model adjusting for sequential case number in a surgeon's experience was used to assess intracorporeal learning curve. RESULTS: Nine hundred sixty-eight patients were included: 279 open, 382 robotic extracorporeal, and 307 robotic intracorporeal. Benign stricture incidence was 11.3% overall: 26 (9.3%) after open, 43 (11.3%) after robotic extracorporeal, and 40 (13.0%) after robotic intracorporeal. An intracorporeal approach was associated with anastomotic stricture on multivariable analysis (HR 1.66; P = .05). After 75 intracorporeal cases, stricture incidence declined from 17.5% to 4.9%. Higher sequential case volume was independently associated with reduced stricture incidence (Hazard Ratio per 10 cases: 0.90; P = .02). CONCLUSION: An intracorporeal approach to urinary reconstruction following robotic radical cystectomy was associated with an increased risk of benign uretero-enteric anastomotic stricture. In surgeons' early experience with intracorporeal diversion the difference in stricture incidence was more pronounced compared to alternative approaches; however, increased intracorporeal case volume was associated with a decline in stricture incidence leading to a modest difference between the 3 surgical approaches overall.

Application of strain and calibration of Förster Resonance Energy Transfer (FRET) emission for in vitro live cell response to cytoskeletal deformation.

Cellular mechanotransduction is an integral part of many crucial physiological processes, but non-invasive tools for quantifying intracellular strain in vivo are not available for complex tissues such as bone. As a first step to address this gap, we have utilized a novel, non-invasive approach to quantify cellular strain in vitro by employing a transfected alpha-actinin Förster Resonance Energy Transfer (FRET) sensor. Following validation experiments, mouse fibroblasts transfected to express FRET sensors were seeded to a silicone membrane and subjected to up to 10% tensile strain mounted on a multi-photon microscope. During tensile strain, fluorescent emission of acceptor (YFP) and donor (CFP) proteins was quantified. YFP/CFP ratio was normalized to the initial baseline (unstretched) ratio for each cell which demonstrates a negative linear correlation between the relative proximity ratio of emission spectra and cell strain, with a mean decrease of 1.017% normalized ratio for every percent strain experienced by the cell. The exciting implications of our findings are that the discovery of the stable correlation between loss of FRET and experimentally applied strain opens intriguing possibilities for future use of this technology with in vivo research, leading to discoveries improving disease treatments in mechanically sensitive tissues such as bone.