Evaluation of Inhaled Nitric Oxide Generation Systems at Altitude.

INTRODUCTION: Inhaled nitric oxide (INO) is a selective pulmonary vasodilator delivered from compressed gas cylinders filled to 2,200 psig (137.8 bar) with 800 ppm of NO in a balance of nitrogen. NO is currently FDA-approved for use in term or near-term infants with hypoxemia and signs of pulmonary hypertension in the absence of cardiac disease. INO has also been shown to improve oxygenation in adults with refractory hypoxemia. Current doctrine precludes the use of NO during military aeromedical transport owing to the requirement for large compressed gas cylinders. We performed a bench evaluation of 2 delivery systems that create NO from room air without the need for pressurized cylinders. MATERIALS AND METHODS: We evaluated 2 portable nitric oxide INO generation systems (LungFit PH, Beyond Air Inc, Garden City, NJ and a prototype NO generator, Odic Inc, Littleton, MA) at ground level, 8,000, and 14,000 feet (2,437 and 4,267 meter) simulated altitude in an altitude chamber. The output from each device was injected into the inspiratory limb of the ventilator circuit that was attached to a test lung. A 731 ventilator (Zoll Medical, Chelmsford, MA) and T1 (Hamilton Medical, Reno, NV) were used employing 24 combinations of ventilator settings each repeated in duplicate. An INOmax DS IR was used to measure delivered INO and NO2 via a sampling line attached in the ventilator circuit inspiratory limb. A fast response oxygen analyzer (O2CAP, Oxigraf Inc, Sunnyvale, CA) was used to measure inspired FiO2. Target INO concentration was 20 ppm. RESULTS: Across all ventilator settings, the LungFit device delivered INO was 19.8 ± 1.6 ppm, 16.1 ± 1.9 ppm, and 11.6 ± 1.7 ppm at ground level, 8,000 ft (2,437 meter), and 14,000 ft (4,267 meter), respectively. The Odic device delivered INO dose was 20.6 ± 1.4 ppm, 21.3 ± 5.5 ppm, and 20.4 ± 9.1 ppm at ground level, 8,000 ft (2,437 meter), and 14,000 ft (4,267 meter), respectively. CONCLUSIONS: Both devices delivered a reliable INO dose at ground level. Altitude significantly affected INO delivery accuracy at 14,000 ft (4,267 meter) (P < 0.01) with both devices and at 8,000 ft (2,437 meter) (P < 0.01) with LungFit. Differences in INO dosage were not statistically significant with the Odic device at 8,000 ft (2,437 meter)(P > 0.05) although there were large variations with selected ventilator settings. With careful monitoring, devices creating INO from room air without cylinders could be used during aeromedical transport without the need for pressurized cylinders.

Individual and neighborhood-level social and deprivation factors impact kidney health in the GLOMMS-CORE study.

Prospective cohort studies of kidney equity are limited by a focus on advanced rather than early disease and selective recruitment. Whole population studies frequently rely on area-level measures of deprivation as opposed to individual measures of social disadvantage. Here, we linked kidney health and individual census records in the North of Scotland (Grampian area), 2011-2021 (GLOMMS-CORE) and identified incident kidney presentations at thresholds of estimated glomerular filtration rate (eGFR) under 60 (mild/early), under 45 (moderate), under 30 ml/min/1.73m2 (advanced), and acute kidney disease (AKD). Household and neighborhood socioeconomic measures, living circumstances, and long-term mortality were compared. Case-mix adjusted multivariable logistic regression (living circumstances), and Cox models (mortality) incorporating an interaction between the household and the neighborhood were used. Among census respondents, there were 48546, 29081, 16116, 28097 incident presentations of each respective eGFR cohort and AKD. Classifications of socioeconomic position by household and neighborhood were related but complex, and frequently did not match. Compared to households of professionals, people with early kidney disease in unskilled or unemployed households had increased mortality (adjusted hazard ratios: 95% confidence intervals) of (1.26: 1.19-1.32) and (1.77: 1.60-1.96), respectively with adjustment for neighborhood indices making little difference. Those within either a deprived household or deprived neighborhood experienced greater mortality, but those within both had the poorest outcomes. Unskilled and unemployed households frequently reported being limited by illness, adverse mental health, living alone, basic accommodation, lack of car ownership, language difficulties, and visual and hearing impairments. Thus, impacts of deprivation on kidney health are spread throughout society-complex, serious, and not confined to those living in deprived neighborhoods.

Protocol for the development and validation of a Polypharmacy Assessment Score.

BACKGROUND: An increasing number of people are using multiple medications each day, named polypharmacy. This is driven by an ageing population, increasing multimorbidity, and single disease-focussed guidelines. Medications carry obvious benefits, yet polypharmacy is also linked to adverse consequences including adverse drug events, drug-drug and drug-disease interactions, poor patient experience and wasted resources. Problematic polypharmacy is 'the prescribing of multiple medicines inappropriately, or where the intended benefits are not realised'. Identifying people with problematic polypharmacy is complex, as multiple medicines can be suitable for people with several chronic conditions requiring more treatment. Hence, polypharmacy is often potentially problematic, rather than always inappropriate, dependent on clinical context and individual benefit vs risk. There is a need to improve how we identify and evaluate these patients by extending beyond simple counts of medicines to include individual factors and long-term conditions. AIM: To produce a Polypharmacy Assessment Score to identify a population with unusual levels of prescribing who may be at risk of potentially problematic polypharmacy. METHODS: Analyses will be performed in three parts: 1. A prediction model will be constructed using observed medications count as the dependent variable, with age, gender and long-term conditions as independent variables. A 'Polypharmacy Assessment Score' will then be constructed through calculating the differences between the observed and expected count of prescribed medications, thereby highlighting people that have unexpected levels of prescribing. Parts 2 and 3 will examine different aspects of validity of the Polypharmacy Assessment Score: 2. To assess 'construct validity', cross-sectional analyses will evaluate high-risk prescribing within populations defined by a range of Polypharmacy Assessment Scores, using both explicit (STOPP/START criteria) and implicit (Medication Appropriateness Index) measures of inappropriate prescribing. 3. To assess 'predictive validity', a retrospective cohort study will explore differences in clinical outcomes (adverse drug reactions, unplanned hospitalisation and all-cause mortality) between differing scores. DISCUSSION: Developing a cross-cutting measure of polypharmacy may allow healthcare professionals to prioritise and risk stratify patients with polypharmacy using unusual levels of prescribing. This would be an improvement from current approaches of either using simple cutoffs or narrow prescribing criteria.

Evaluation of a Rebreathing System for Use with Portable Mechanical Ventilators.

INTRODUCTION: Maximizing the capabilities of available lowflow oxygen is key to providing adequate oxygen to prevent/treat hypoxemia and conserve oxygen. We designed a closed-circuit system that allows rebreathing of gases while scrubbing carbon dioxide (CO2) in conjunction with portable mechanical ventilators in a bench model. METHODS: We evaluated the system using two portable mechanical ventilators currently deployed by the Department of Defense-Zoll 731 and AutoMedx SAVe II-over a range of ventilator settings and lung models, using 1 and 3L/min low-flow oxygen into a reservoir bag. We measured peak inspired oxygen concentration (FiO2), CO2-absorbent life, gas temperature and humidity, and the effect of airway suctioning and ventilator disconnection on FiO2 on ground and at altitude. RESULTS: FiO2 was =0.9 across all ventilator settings and altitudes using both oxygen flows. CO2-absorbent life was >7 hours. Airway humidity range was 87%-97%. Mean airway temperature was 25.4°C (SD 0.5°C). Ten-second suctioning reduced FiO2 22%-48%. Thirtysecond ventilator disconnect reduced FiO2 29%-63% depending on oxygen flow used. CONCLUSION: Use of a rebreathing system with mechanical ventilation has the potential for oxygen conservation but requires diligent monitoring of inspired FiO2 and CO2 to avoid negative consequences.

Defining, identifying and addressing problematic polypharmacy within multimorbidity in primary care: a scoping review.

INTRODUCTION: Polypharmacy and multimorbidity pose escalating challenges. Despite numerous attempts, interventions have yet to show consistent improvements in health outcomes. A key factor may be varied approaches to targeting patients for intervention. OBJECTIVES: To explore how patients are targeted for intervention by examining the literature with respect to: understanding how polypharmacy is defined; identifying problematic polypharmacy in practice; and addressing problematic polypharmacy through interventions. DESIGN: We performed a scoping review as defined by the Joanna Briggs Institute. SETTING: The focus was on primary care settings. DATA SOURCES: Medline, Embase, Cumulative Index to Nursing and Allied Health Literature and Cochrane along with ClinicalTrials.gov, Science.gov and WorldCat.org were searched from January 2004 to February 2024. ELIGIBILITY CRITERIA: We included all articles that had a focus on problematic polypharmacy in multimorbidity and primary care, incorporating multiple types of evidence, such as reviews, quantitative trials, qualitative studies and policy documents. Articles focussing on a single index disease or not written in English were excluded. EXTRACTION AND ANALYSIS: We performed a narrative synthesis, comparing themes and findings across the collective evidence to draw contextualised insights and conclusions. RESULTS: In total, 157 articles were included. Case-finding methods often rely on basic medication counts (often five or more) without considering medical history or whether individual medications are clinically appropriate. Other approaches highlight specific drug indicators and interactions as potentially inappropriate prescribing, failing to capture a proportion of patients not fitting criteria. Different potentially inappropriate prescribing criteria also show significant inconsistencies in determining the appropriateness of medications, often neglecting to consider multimorbidity and underprescribing. This may hinder the identification of the precise population requiring intervention. CONCLUSIONS: Improved strategies are needed to target patients with polypharmacy, which should consider patient perspectives, individual factors and clinical appropriateness. The development of a cross-cutting measure of problematic polypharmacy that consistently incorporates adjustment for multimorbidity may be a valuable next step to address frequent confounding.

Systemic Inflammatory Effect of Hypobaria During Aeromedical Evacuation after Porcine Traumatic Brain Injury.

BACKGROUND: Traumatic brain injury (TBI)-related morbidity is caused largely by secondary injury resulting from hypoxia, excessive sympathetic drive, and uncontrolled inflammation. Aeromedical evacuation (AE) is used by the military for transport of wounded soldiers to higher levels of care. We hypothesized that the hypobaric, hypoxic conditions of AE may exacerbate uncontrolled inflammation after TBI that could contribute to more severe TBI-related secondary injury. STUDY DESIGN: Thirty-six female pigs were used to test TBI vs Sham TBI, hypoxia vs normoxia, and hypobaria vs ground conditions. TBI was induced by controlled cortical injury, hypobaric conditions of 12,000 ft were established in an altitude chamber, and hypoxic exposure was titrated to 85% SpO 2 while at altitude. Serum cytokines, ubiquitin C-terminal hydrolase L1, and TBI biomarkers were analyzed via ELISA. Gross analysis and staining of cortex and hippocampus tissue was completed for glial fibrillary acidic protein and phosphorylated tau. RESULTS: Serum interleukin-1ß, interleukin-6, and tumor necrosis factor-α were significantly elevated after TBI in pigs exposed to altitude-induced hypobaria/hypoxia, as well as hypobaria alone, compared with ground level/normoxia. No difference in TBI biomarkers after TBI or hypobaric, hypoxic exposure was noted. No difference in brain tissue glial fibrillary acidic protein or phosphorylated tau when comparing the most different conditions of Sham TBI + ground or normoxia with the TBI + hypobaria/hypoxia group was noted. CONCLUSIONS: The hypobaric environment of AE induces systemic inflammation after TBI. Severe inflammation may play a role in exacerbating secondary injury associated with TBI and contribute to worse neurocognitive outcomes. Measures should be taken to minimize barometric and oxygenation changes during AE after TBI.

Just Say NO: Inhaled Nitric Oxide Effect on Respiratory Parameters Following Traumatic Brain Injury in Humans and a Porcine Model.

INTRODUCTION: The mechanism of post-traumatic brain injury (TBI) hypoxemia involves ventilation/perfusion mismatch and loss of pulmonary hypoxic vasoconstriction. Inhaled nitric oxide (iNO) has been studied as an adjunct treatment to avoid the use of high positive end-expiratory pressure and inspired oxygen in treatment-refractory hypoxia. We hypothesized that iNO treatment following TBI would improve systemic and cerebral oxygenation via improved matching of pulmonary perfusion and ventilation. METHODS: Thirteen human patients with isolated TBI were enrolled and randomized to receive either placebo or iNO with measured outcomes including pulmonary parameters, blood gas data, and intracranial pressure (ICP) /perfusion. To complement this study, a porcine model of TBI (including 10 swine) was utilized with measured outcomes of brain tissue blood flow and oxygenation, ventilator parameters, and blood gas data both after administration and following drug removal and clearance. RESULTS: There were no clinically significant changes in pulmonary parameters in either the human or porcine arm following administration of iNO when compared to either the placebo group (human arm) or the internal control (porcine arm). Analysis of pooled human data demonstrated the preservation of alveolar recruitment in TBI patients. There were no clinically significant changes in human ICP or cerebral perfusion pressure following iNO administration compared to controls. CONCLUSIONS: iNO had no significant effect on clinically relevant pulmonary parameters or ICPs following TBI in both human patients and a porcine model. The pressure-based recruitment of the human lungs following TBI was preserved. Further investigation will be needed to determine the degree of utility of iNO in the setting of hypoxia after polytrauma.

A primary care research agenda for multiple long-term conditions: a Delphi study.

BACKGROUND: Multiple long-term conditions (MLTC), also known as multimorbidity, has been identified as a priority research topic globally. Research priorities from the perspectives of patients and research funders have been described. Although most care for MLTC is delivered in primary care, the priorities of academic primary care have not been identified. AIM: To identify and prioritise the academic primary care research agenda for MLTC. DESIGN AND SETTING: This was a three-phase study with primary care MLTC researchers from the UK and other high-income countries. METHOD: The study consisted of: an open-ended survey question, a face-to-face workshop to elaborate questions with researchers from the UK and Ireland, and a two-round Delphi consensus survey with international multimorbidity researchers. RESULTS: Twenty-five primary care researchers responded to the initial open-ended survey and generated 84 potential research questions. In the subsequent workshop discussion (n = 18 participants), this list was reduced to 31 questions. The longlist of 31 research questions was included in round 1 of the Delphi; 27 of the 50 (54%) round 1 invitees and 24 of the 27 (89%) round 2 invitees took part in the Delphi. Ten questions reached final consensus. These questions focused broadly on addressing the complexity of the patient group with development of new models of care for multimorbidity, and methods and data development. CONCLUSION: These high-priority research questions offer funders and researchers a basis on which to build future grant calls and research plans. Addressing complexity in this research is needed to inform improvements in systems of care and for disease prevention.

Informing understanding of coordination of care for patients with heart failure with preserved ejection fraction: a secondary qualitative analysis.

BACKGROUND: Patients with heart failure with preserved ejection fraction (HFpEF) are a complex and underserved group. They are commonly older patients with multiple comorbidities, who rely on multiple healthcare services. Regional variation in services and resourcing has been highlighted as a problem in heart failure care, with few teams bridging the interface between the community and secondary care. These reports conflict with policy goals to improve coordination of care and dissolve boundaries between specialist services and the community. AIM: To explore how care is coordinated for patients with HFpEF, with a focus on the interface between primary care and specialist services in England. METHODS: We applied systems thinking methodology to examine the relationship between work-as-imagined and work-as-done for coordination of care for patients with HFpEF. We analysed clinical guidelines in conjunction with a secondary applied thematic analysis of semistructured interviews with healthcare professionals caring for patients with HFpEF including general practitioners, specialist nurses and cardiologists and patients with HFpEF themselves (n=41). Systems Thinking for Everyday Work principles provided a sensitising theoretical framework to facilitate a deeper understanding of how these data illustrate a complex health system and where opportunities for improvement interventions may lie. RESULTS: Three themes (working with complexity, information transfer and working relationships) were identified to explain variability between work-as-imagined and work-as-done. Participants raised educational needs, challenging work conditions, issues with information transfer systems and organisational structures poorly aligned with patient needs. CONCLUSIONS: There are multiple challenges that affect coordination of care for patients with HFpEF. Findings from this study illuminate the complexity in coordination of care practices and have implications for future interventional work.

Risk of Falls and Fractures in Individuals With Cataract, Age-Related Macular Degeneration, or Glaucoma.

Importance: Three leading disease causes of age-related visual loss are cataract, age-related macular degeneration (AMD), and glaucoma. Although all 3 eye diseases have been implicated with falls and fracture risk, evidence is mixed, with the contribution of different eye diseases being uncertain. Objective: To examine whether people with cataract, AMD, or glaucoma have higher risks of falls or fractures than those without. Design, Setting, and Participants: This cohort study was a population-based study in England using routinely collected electronic health records from the Clinical Practice Research Datalink (CPRD) GOLD and Aurum primary care databases with linked hospitalization and mortality records from 2007 to 2020. Participants were people with cataract, AMD, or glaucoma matched to comparators (1:5) by age, sex, and general practice. Data were analyzed from May 2021 to June 2023. Exposures: For each eye disease, we estimated the risk of falls or fractures using separate multivariable Cox proportional hazards regression models. Main Outcomes: Two primary outcomes were incident falls and incident fractures derived from general practice, hospital, and mortality records. Secondary outcomes were incident fractures of specific body sites. Results: A total of 410 476 people with cataract, 75 622 with AMD, and 90 177 with glaucoma were matched (1:5) to 2 034 194 (no cataract), 375 548 (no AMD), and 448 179 (no glaucoma) comparators. The mean (SD) age was 73.8 (11.0) years, 79.4 (9.4) years, and 69.8 (13.1) years for participants with cataract, AMD, or glaucoma, respectively. Compared with comparators, there was an increased risk of falls in those with cataract (adjusted hazard ratio [HR], 1.36; 95% CI, 1.35-1.38), AMD (HR, 1.25; 95% CI, 1.23-1.27), and glaucoma (HR, 1.38; 95% CI, 1.35-1.41). Likewise for fractures, there were increased risks in all eye diseases, with an HR of 1.28 (95% CI, 1.27-1.30) in the cataract cohort, an HR of 1.18 (95% CI, 1.15-1.21) for AMD, and an HR of 1.31 (95% CI, 1.27-1.35) for glaucoma. Site-specific fracture analyses revealed increases in almost all body sites (including hip, spine, forearm, skull or facial bones, pelvis, ribs or sternum, and lower leg fractures) compared with matched comparators. Conclusions and Relevance: The results of this study support recognition that people with 1 or more of these eye diseases are at increased risk of both falls and fractures. They may benefit from improved advice, access, and referrals to falls prevention services.

Validation of Preload Assessment Technologies at Altitude in a Porcine Model of Hemorrhage.

INTRODUCTION: Dynamic preload assessment measures including pulse pressure variation (PPV), stroke volume variation (SVV), pleth variability index (PVI), and hypotension prediction index (HPI) have been utilized clinically to guide fluid management decisions in critically ill patients. These values aid in the balance of correcting hypotension while avoiding over-resuscitation leading to respiratory failure and increased mortality. However, these measures have not been previously validated at altitude or in those with temporary abdominal closure (TAC). METHODS: Forty-eight female swine (39 ± 2 kg) were separated into eight groups (n = 6) including all combinations of flight versus ground, hemorrhage versus no hemorrhage, and TAC versus no TAC. Flight animals underwent simulated aeromedical evacuation via an altitude chamber at 8000 ft. Hemorrhagic shock was induced via stepwise hemorrhage removing 10% blood volume in 15-min increments to a total blood loss of 40% or a mean arterial pressure of 35 mmHg. Animals were then stepwise transfused with citrated shed blood with 10% volume every 15 min back to full blood volume. PPV, SVV, PVI, and HPI were monitored every 15 min throughout the simulated aeromedical evacuation or ground control. Blood samples were collected and analyzed for serum levels of serum IL-1ß, IL-6, IL-8, and TNF-α. RESULTS: Hemorrhage groups demonstrated significant increases in PPV, SVV, PVI, and HPI at each step compared to nonhemorrhage groups. Flight increased PPV (P = 0.004) and SVV (P = 0.003) in hemorrhaged animals. TAC at ground level increased PPV (P < 0.0001), SVV (P = 0.0003), and PVI (P < 0.0001). When TAC was present during flight, PPV (P = 0.004), SVV (P = 0.003), and PVI (P < 0.0001) values were decreased suggesting a dependent effect between altitude and TAC. There were no significant differences in serum IL-1ß, IL-6, IL-8, or TNF-α concentration between injury groups. CONCLUSIONS: Based on our study, PPV and SVV are increased during flight and in the presence of TAC. Pleth variability index is slightly increased with TAC at ground level. Hypotension prediction index demonstrated no significant changes regardless of altitude or TAC status, however this measure was less reliable once the resuscitation phase was initiated. Pleth variability index may be the most useful predictor of preload during aeromedical evacuation as it is a noninvasive modality.

Providing care to marginalised communities: a qualitative study of community pharmacy teams.

BACKGROUND: Health inequalities in the UK are widening, particularly since the COVID-19 pandemic. Community pharmacies are the most visited healthcare provider in England and are ideally placed to provide and facilitate access to care for those most disadvantaged. AIM: To explore the experiences and needs of community pharmacy teams in providing care for marginalised groups and how this has changed since the COVID-19 pandemic. DESIGN AND SETTING: A qualitative study in community pharmacy and across primary care. METHOD: Semi-structured interviews were undertaken with members of community pharmacy teams, primary care network (PCN) pharmacists, GPs, and nurses in the North of England. RESULTS: In total, 31 individuals participated in an interview (26 pharmacy staff, three GPs, and two nurses). Most participants acknowledged that their pharmacy had become busier since COVID-19 because of increased footfall compounded by patient difficulties in navigating remote digital systems. Few participants had received any formal training on working with marginalised communities; however, organisational barriers (such as lack of access to translation facilities) combined with interorganisational barriers (such as lack of integrated care) made it more difficult to provide care for some marginalised groups. Despite this, the continuity of care provided by many pharmacies was viewed as an important factor in enabling marginalised groups to access and receive care. CONCLUSION: There are opportunities to better utilise the skills of community pharmacy teams. Resources, such as access to translation services, and interventions to enable better communication between community pharmacy teams and other primary care services, such as general practice, are essential.

Effectiveness of Negative Pressure Wound Therapy During Aeromedical Evacuation Following Soft Tissue Injury and Infection.

INTRODUCTION: Negative pressure wound therapy (NPWT) is utilized early after soft tissue injury to promote tissue granulation and wound contraction. Early post-injury transfers via aeromedical evacuation (AE) to definitive care centers may actually induce wound bacterial proliferation. However, the effectiveness of NPWT or instillation NPWT in limiting bacterial proliferation during post-injury AE has not been studied. We hypothesized that instillation NPWT during simulated AE would decrease bacterial colonization within simple and complex soft tissue wounds. METHODS: The porcine models were anesthetized before any experiments. For the simple tissue wound model, two 4-cm dorsal wounds were created in 34.9 ± 0.6 kg pigs and were inoculated with Acinetobacter baumannii (AB) or Staphylococcus aureus 24 hours before a 4-hour simulated AE or ground control. During AE, animals were randomized to one of the five groups: wet-to-dry (WTD) dressing, NPWT, instillation NPWT with normal saline (NS-NPWT), instillation NPWT with Normosol-R® (NM-NPWT), and RX-4-NPWT with the RX-4 system. For the complex musculoskeletal wound, hind-limb wounds in the skin, subcutaneous tissue, peroneus tertius muscle, and tibia were created and inoculated with AB 24 hours before simulated AE with WTD or RX-4-NPWT dressings. Blood samples were collected at baseline, pre-flight, and 72 hours post-flight for inflammatory cytokines interleukin (IL)-1ß, IL-6, IL-8 and tumor necrosis factor alpha. Wound biopsies were obtained at 24 hours and 72 hours post-flight, and the bacteria were quantified. Vital signs were measured continuously during simulated AE and at each wound reassessment. RESULTS: No significant differences in hemodynamics or serum cytokines were noted between ground or simulated flight groups or over time in either wound model. Simulated AE alone did not affect bacterial proliferation compared to ground controls. The simple tissue wound arm demonstrated a significant decrease in Staphylococcus aureus and AB colony-forming units at 72 hours after simulated AE using RX-4-NPWT. NS-NPWT during AE more effectively prevented bacterial proliferation than the WTD dressing. There was no difference in colony-forming units among the various treatment groups at the ground level. CONCLUSION: The hypoxic, hypobaric environment of AE did not independently affect the bacterial growth after simple tissue wound or complex musculoskeletal wound. RX-4-NPWT provided the most effective bacterial reduction following simulated AE, followed by NS-NPWT. Future research will be necessary to determine ideal instillation fluids, negative pressure settings, and dressing change frequency before and during AE.

Treatment burden in multiple long-term conditions: a mixed-methods study protocol.

BACKGROUND: Treatment burden represents the work patients undertake because of their health care, and the impact of that effort on the patient. Most research has focused on older adults (aged >65 years) with multiple long-term conditions (multimorbidity) (MLTC-M), but there are now more younger adults (aged 18-65 years) living with MLTC-M and they may experience treatment burden differently. Understanding experiences of treatment burden, and identifying those most at risk of high treatment burden, are important for designing primary care services to meet their needs. AIM: To understand the treatment burden associated with MLTC-M, for people aged 18-65 years, and how primary care services affect this burden. DESIGN & SETTING: Mixed-methods study in up to 33 primary care practices in two UK regions. METHOD: The following two approaches will be used: (i) in-depth qualitative interviews with adults living with MLTC-M (approximately 40 participants) to understand their experiences of treatment burden and the impact of primary care, with a think-aloud aspect to explore face validity of a novel short treatment burden questionnaire (STBQ) for routine clinical use in the initial 15 interviews; (ii) cross-sectional patient survey (approximately 1000 participants), with linked routine medical record data to examine the factors associated with treatment burden for people living with MLTC-M, and to test the validity of STBQ. CONCLUSION: This study will generate in-depth understanding of the treatment burden experienced by people aged 18-65 years living with MLTC-M, and how primary care services affect this burden. This will inform further development and testing of interventions to reduce treatment burden, and potentially influence MLTC-M trajectories and improve health outcomes.

Cumulative complexity: a qualitative analysis of patients' experiences of living with heart failure with preserved ejection fraction.

AIMS: To investigate how heart failure with preserved ejection fraction (HFpEF), within the context of limited clinical services, impacts patients' lives. METHODS AND RESULTS: Secondary thematic analysis informed by the cumulative complexity model (CCM), of interview transcripts from 77 people diagnosed with HFpEF and their carers. Four themes corresponding to the core concepts of workload, capacity, access, and outcome described in the CCM were generated. Theme 1: Shouldering a heavy workload described the many tasks expected of people living with HFpEF. Theme 2: The multiple threats to capacity described how patients and carers strived to engage with this work, but were often faced with multiple threats such as symptoms and mobility limitations. Deficient illness identity (Theme 3) reflects how HFpEF either was not recognized or was perceived as a more benign form of HF and therefore afforded less importance or priority. These themes contributed to a range of negative physical, social, and psychological outcomes and the perception of loss of control described in Theme 4: Spiraling complexity. CONCLUSIONS: The constellation of HFpEF, multi-morbidity, and ageing creates many demands that people with HFpEF are expected to manage. Concurrently, the same syndromes threaten their ability to physically enact this work. Patients' recollections of their interactions with health professionals suggest that there is a widespread misunderstanding of HFpEF, which can prohibit access to care that could potentially reduce or prevent deterioration.

Medication Holds in CKD During Acute Volume-Depleting Illnesses: A Randomized Controlled Trial of a "Sick-Day" Protocol.

Rationale & Objective: Some drugs prescribed for chronic kidney disease (CKD) may become hazardous on sick days with volume depletion by increasing the risk of acute kidney injury (AKI) and kidney function loss; however, the risks and benefits of their use during intercurrent illness is unknown. Study Design: 6-month pragmatic trial examining a sick-day protocol to determine if withholding prespecified drugs during a volume-depleting illness reduces the incidence AKI or kidney function loss in CKD. Setting & Participants: 315 veterans with stage 3-5 CKD, treated with a renin-angiotensin-aldosterone inhibitor blocker, diuretic, nonsteroidal anti-inflammatory drug, or metformin were randomized into the study with n = 159 and n = 156 in sick-day protocol and usual care groups, respectively. Intervention: Sick-day protocol administered via interactive voice response system (IVRS) or usual care with 6-month follow-up. Outcomes: The outcomes of the study are as follows: (1) Change in kidney function, (2) incidence of AKI based on International Classification of Diseases, Tenth Revision codes and ambulatory laboratory testing, (3) urgent service utilizations, and (4) sick days. Results: The mean age was 70.1 ± 7.4 and 69.2 ± 8.1 years, with a mean baseline glomerular filtration rate (GFR) of 43.1 ± 13.1 and 43.8 ± 13.0 mL/min/1.73 m2, and 112 (70%) and 100 (64%) of participants with diabetes in the sick-day protocol and usual care groups, respectively. The mean change in GFR in the sick-day protocol and usual care groups from baseline to 6-month follow-up, adjusting for baseline GFR, was -0.71 (95% CI, -2.11 to 0.69) and -0.72 (95% CI, -2.12 to 0.68), respectively, with no significant difference, P = 0.99. Hospitalizations in the sick-day protocol and usual care groups were 11.5/100 and 8.4/100 events per person-months, respectively, with the adjusted rate ratio not significantly increased (prevalence ratio, 1.30; 95% CI, 0.96-1.76). Participants interacted with the IVRS in 81% of expected weeks and 19 had one or more qualifying events. In 33 true sick days, participants correctly followed the protocol in only 14. Limitations: Low incidence of sick days over the 6-month period of the study. Conclusions: The sick-day protocol was not associated with a significant reduction in AKI episodes or kidney function loss in a high-risk CKD population. Engagement with the IVRS was high, but successful implementation of the sick-day protocol was not optimal. Trial Registration: ClinicalTrials.gov; NCT03141905.

Postinjury Treatment to Mitigate the Effects of Aeromedical Evacuation After Traumatic Brain Injury in a Porcine Model.

INTRODUCTION: Early aeromedical evacuation after traumatic brain injury (TBI) has been associated with worse neurologic outcomes in murine studies and military populations. The goal of this study was to determine if commonly utilized medications, including allopurinol, propranolol, or tranexamic acid (TXA), could mitigate the secondary traumatic brain injury experienced during the hypobaric and hypoxic environment of aeromedical evacuation. METHODS: Porcine TBI was induced via controlled cortical injury. Twenty nonsurvival pigs were separated into four groups (n = 5 each): TBI+25 mL normal saline (NS), TBI+4 mg propranolol, TBI+100 mg allopurinol, and TBI+1g TXA. The pigs then underwent simulated AE to an altitude of 8000 ft for 4 h with an SpO2 of 82-85% and were sacrificed 4 h later. Hemodynamics, serum cytokines, and hippocampal p-tau accumulation were assessed. An additional survival cohort was partially completed with TBI/NS (n = 5), TBI/propranolol (n = 2) and TBI/allopurinol groups (n = 2) survived to postinjury day 7. RESULTS: There were no significant differences in hemodynamics, tissue oxygenation, cerebral blood flow, or physiologic markers between treatment groups and saline controls. Transient differences in IL-1b and IL-6 were noted but did not persist. Neurological Severity Score (NSS) was significantly lower in the TBI + allopurinol group on POD one compared to NS and propranolol groups. P-tau accumulation was decreased in the nonsurvival animals treated with allopurinol and TXA compared to the TBI/NS group. CONCLUSIONS: Allopurinol, propranolol, and TXA, following TBI, do not induce adverse changes in systemic or cerebral hemodynamics during or after a simulated postinjury flight. While transient changes were noted in systemic cytokines and p-tau accumulation, further investigation will be needed to determine any persistent neurological effects of injury, flight, and pharmacologic treatment.

Oxygenation and Respiratory System Compliance Associated With Pulmonary Contusion.

BACKGROUND: Blunt pulmonary contusions are associated with severe chest injuries and are independently associated with worse outcomes. Previous preclinical studies suggest that contusion progression precipitates poor pulmonary function; however, there are few current clinical data to corroborate this hypothesis. We examined pulmonary dynamics and oxygenation in subjects with pulmonary contusions to evaluate for impaired respiratory function. METHODS: A chest injury database was reviewed for pulmonary contusions over 5 years at an urban trauma center. This database was expanded to capture mechanical ventilation parameters for the first 7 days on all patients with pulmonary contusion and who were intubated. Daily [Formula: see text]:[Formula: see text], oxygenation indexes (OI), and dynamic compliances were calculated. Pulmonary contusions were stratified by severity. The Fisher exact and chi square tests were performed on categorical variables, and Mann-Whitney U-tests were performed on continuous variables. Significance was assessed at a level of 0.05. RESULTS A TOTAL OF: 1,176 patients presented with pulmonary contusions, of whom, 301 subjects (25.6%) required intubation and had available invasive mechanical ventilation data. Of these, 144 (47.8%) had mild-moderate pulmonary contusion and 157 (52.2%) had severe pulmonary contusion. Overall injury severity score was high, with a median injury severity score of 29 (interquartile range, 22-38). The median duration of mechanical ventilation for mild-moderate pulmonary contusion was 7 d versus 10 d for severe pulmonary contusion (P = .048). All the subjects displayed moderate hypoxemia, which worsened until day 4-5 after intubation. Severe pulmonary contusion was associated with significantly worse early hypoxia on day 1 and day 2 versus mild-moderate pulmonary contusion. Severe pulmonary contusion also had a higher oxygenation index than mild-moderate pulmonary contusion. This trend persisted after adjustment for other factors, including transfusion and fluid administration. CONCLUSIONS: Pulmonary contusions played an important role in the course of subjects who were acutely injured and required mechanical ventilation. Contusions were associated with hypoxemia not fully characterized by [Formula: see text]: [Formula: see text], and severe contusions had durable elevations in the oxygenation index despite confounders.