Triggered Gate Opening and Breathing Effects during Selective CO2 Adsorption by Merlinoite Zeolite.

Zeolites with flexible structures that adapt to coordinate extraframework cations when dehydrated show a rich variety of gas adsorption behavior and can be tuned to optimize kinetics and selectivity. Merlinoite zeolite (topology type MER) with Si/Al = 3.8 has been prepared in Na, K, and Cs forms and its structural response to dehydration measured: the unit cell volumes decrease by 9.8%, 7.7%, and 7.1% for Na-, K-, and Cs-MER, respectively. Na-MER adopts Immm symmetry, while K- and Cs-MER display P42/nmc symmetry, the difference attributed to the preferred locations of the smaller and larger cations. Their performance in CO2 adsorption has been measured by single-component isotherms and by mixed gas (CO2/CH4/He) breakthrough experiments. The differing behavior of the cation forms can be related to structural changes during CO2 uptake measured by variable-pressure PXRD. All show a "breathing" transition from narrow to wide pore forms. Na- and Cs-MER show non-Type I isotherms and kinetically-limited CO2 adsorption and delivery of pure CH4 in CO2/CH4 separation. However, K-MER shows good uptake of CO2 (3.5 mmol g-1 at 1 bar and 298 K), rapid adsorption and desorption kinetics, and promising CO2/CH4 separation. Furthermore, the narrow-to-wide pore transition occurs rapidly and at very low pCO2 via a "triggered" opening. This has the consequence that whereas no CH4 is adsorbed from a pure stream, addition of low levels of CO2 can result in pore opening and uptake of both CO2 and CH4, although in a continuous stream the CH4 is replaced selectively by CO2. This observed cation size-dependent adsorption behavior derives from a fine energetic balance between different framework configurations in these cation-controlled molecular sieves.

Endovascular management of traumatic peripheral arterial injuries.

BACKGROUND: Traumatic injuries to peripheral arterial vessels are increasingly managed with endovascular techniques. Early small series have suggested that endovascular therapy is feasible and decreases operative blood loss, but these data are limited. The purpose of this study was to evaluate the feasibility and outcomes of endovascular management of nonaortic arterial trauma. MATERIALS AND METHODS: We reviewed records of traumatic nonaortic arterial injuries presenting at an urban level 1 trauma center from December 2009-July 2013. Patients undergoing treatment in interventional radiology and patients whose injuries occurred >72 h before presentation were excluded. Demographics, indicators of injury severity, operative blood loss, transfusion requirements, and clinical outcome were compared between patients undergoing endovascular and open management using appropriate inferential statistics. RESULTS: During the study period, 17 patients underwent endovascular interventions and 20 had open surgery. There were 19 upper extremity and/or thoracic outlet arterial injuries, 15 lower extremity injuries and 11 pelvic injuries. Endovascular cases were completed using a vascular imaging C-arm in a standard operating room. Estimated blood loss during the primary procedure was significantly lower with endovascular management (150 versus 825 cc, P < 0.001). No differences were observed between cohorts in age, injury severity score, intensive care unit length of stay, arterial pH, transfusion requirements, inpatient complication rate, or mortality. CONCLUSIONS: Our experience with endovascular management demonstrates its feasibility with commonly available tools. Operative blood loss may be significantly decreased using endovascular techniques. Further study is needed to refine patient selection criteria and to define long-term outcomes.

Surgical follow-up costs disproportionately impact low-income patients.

BACKGROUND: Surgical procedures have significant costs at the national level, but the financial burden on patients is equally important. Patients' out-of-pocket costs for surgery and surgical care include not only direct medical costs but also the indirect cost of lost wages and direct nonmedical costs including transportation and childcare. We hypothesized that the nonmedical costs of routine postoperative clinic visits disproportionately impact low-income patients. MATERIALS AND METHODS: This was a cross-sectional study performed in the postoperative acute care surgery clinic at a large, urban county hospital. A survey containing items about social, demographic, and financial data was collected from ambulatory patients. Nonmedical costs were calculated as the sum of transportation, childcare, and lost wages. Costs and cost to income ratios were compared between income strata. RESULTS: Ninety-seven patients responded to the survey of which 59 reported all items needed for cost calculations. The median calculated cost of a clinic visit was $27 (interquartile range $18-59). Components of this cost were $16 ($14-$20) for travel, $22 ($17-$50) for childcare among patients requiring childcare, and $0 ($0-$30) in lost wages. Low-income patients had significantly higher (P = 0.0001) calculated cost to income ratios, spending nearly 10% of their monthly income on these costs. CONCLUSIONS: The financial burden of routine postoperative clinic visits is significant. Consistent with our hypothesis, the lowest income patients are disproportionately impacted, spending nearly 10% of their monthly income on costs associated with the clinic visit. Future cost-containment efforts should examine alternative, lower cost methods of follow-up, which reduce financial burden.

Utility of routine postoperative visit after appendectomy and cholecystectomy with evaluation of mobile technology access in an urban safety net population.

BACKGROUND: The value of routine postoperative visits after general surgery remains unclear. The objective of this study was to evaluate the utility of routine postoperative visits after appendectomy and cholecystectomy and to determine access to mobile technology as an alternative platform for follow-up. METHODS: Retrospective review of 219 appendectomies and 200 cholecystectomies performed at a safety net hospital. One patient underwent both surgeries. Patient demographics, duration of clinic visit, and need for additional imaging, tests or readmissions were recorded. Access to mobile technology was surveyed by a validated questionnaire. RESULTS: Of 418 patients, 84% percent completed a postoperative visit. At follow-up, 58 patients (14%) required 70 interventions, including staple removal (16, 23%), suture removal (4, 6%), drain removal (8, 11%), additional follow-up (20, 28%), medication action (16, 21%), additional imaging (3, 4%), and readmission (1, 1%). Occupational paperwork (62) and nonsurgical clinic referrals (28) were also performed. Average check-in to check-out time was 100 ± 54 min per patient. One intervention was performed for every 7.8 h of time in the clinic. Additionally, 88% of the surveyed population reported access to cell phone technology, and 69% of patients <40 y had smartphone access. CONCLUSIONS: Routine in-person follow-up after surgery consumes significant time and resources for patients and healthcare systems but has little impact on patient care. Most of the work done in the clinic is administrative and could be completed using mobile technology, which is pervasive in our population.

Constructing post-surgical discharge instructions through a Delphi consensus methodology.

OBJECTIVE: Patient education materials are a crucial part of physician-patient communication. We hypothesize that available discharge instructions are difficult to read and fail to address necessary topics. Our objective is to evaluate readability and content of surgical discharge instructions using thyroidectomy to develop standardized discharge materials. METHODS: Thyroidectomy discharge materials were analyzed for readability and assessed for content. Fifteen endocrine surgeons participated in a modified Delphi consensus panel to select necessary topics. Using readability best practices, we created standardized discharge instructions which included all selected topics. RESULTS: The panel evaluated 40 topics, selected 23, deemed 4 inappropriate, consolidated 5, and did not reach consensus on 8 topics after 4 rounds. The evaluated instructions' reading levels ranged from grade 6.5 to 13.2; none contained all consensus topics. CONCLUSION: Current post surgical thyroidectomy discharge instructions are more difficult to read than recommended by literacy standards and omit consensus warning signs of major complications. Our easy-to-read discharge instructions cover pertinent topics and may enhance patient education. Delphi methodology is useful for developing post-surgical instructions. PRACTICE IMPLICATIONS: Patient education materials need appropriate readability levels and content. We recommend the Delphi method to select content using consensus expert opinion whenever higher level data is lacking.

Mixed-Methods Analysis of Factors Impacting Use of a Postoperative mHealth App.

BACKGROUND: Limited communication and care coordination following discharge from hospitals may contribute to surgical complications. Smartphone apps offer a novel mechanism for communication and care coordination. However, factors which may affect patient app use in a postoperative, at-home setting are poorly understood. OBJECTIVE: The objectives of this study were to (1) gauge interest in smartphone app use among patients after colorectal surgery and (2) better understand factors affecting patient app use in a postoperative, at-home setting. METHODS: A prospective feasibility study was performed at a hospital that principally serves low socioeconomic status patients. After colorectal surgery, patients were enrolled and given a smartphone app, which uses previously validated content to provide symptom-based recommendations. Patients were instructed to use the app daily for 14 days after discharge. Demographics and usability data were collected at enrollment. Usability was measured with the System Usability Scale (SUS). At follow-up, the SUS was repeated and patients underwent a structured interview covering ease of use, willingness to use, and utility of use. Two members of the research team independently reviewed the field notes from follow-up interviews and extracted the most consistent themes. Chart and app log reviews identified clinical endpoints. RESULTS: We screened 115 patients, enrolled 20 patients (17.4%), and completed follow-up interviews with 17 patients (85%). Reasons for nonenrollment included: failure to meet inclusion criteria (47/115, 40.9%), declined to participate (26/115, 22.6%), and other reasons (22/115, 19.1%). There was no difference in patient ratings between usability at first-use and after extended use, with SUS scores greater than the 95th percentile at both time points. Despite high usability ratings, 6/20 (30%) of patients never used the app at home after hospital discharge and 2/20 (10%) only used the app once. Interviews revealed three themes related to app use: (1) patient-related barriers could prevent use even though the app had high usability scores; (2) patients viewed the app as a second opinion, rather than a primary source of information; and (3) many patients viewed the app as an external burden. CONCLUSIONS: Use patterns in this study, and response rates after prompts to contact the operative team, suggest that apps need to be highly engaging to be adopted by patients. The growing penetration of smartphones and the proliferation of app-based interventions are unlikely to improve care coordination and communication, unless apps address the barriers and patient perceptions identified in this study. This study shows that high usability alone is not sufficient to motivate patients to use smartphone apps in the postoperative period.