The endogenous circadian system worsens asthma at night independent of sleep and other daily behavioral or environmental cycles.

Asthma often worsens at night. To determine if the endogenous circadian system contributes to the nocturnal worsening of asthma, independent of sleep and other behavioral and environmental day/night cycles, we studied patients with asthma (without steroid use) over 3 wk in an ambulatory setting (with combined circadian, environmental, and behavioral effects) and across the circadian cycle in two complementary laboratory protocols performed in dim light, which separated circadian from environmental and behavioral effects: 1) a 38-h "constant routine," with continuous wakefulness, constant posture, 2-hourly isocaloric snacks, and 2) a 196-h "forced desynchrony" incorporating seven identical recurring 28-h sleep/wake cycles with all behaviors evenly scheduled across the circadian cycle. Indices of pulmonary function varied across the day in the ambulatory setting, and both laboratory protocols revealed significant circadian rhythms, with lowest function during the biological night, around 4:00 AM, uncovering a nocturnal exacerbation of asthma usually unnoticed or hidden by the presence of sleep. We also discovered a circadian rhythm in symptom-based rescue bronchodilator use (ß2-adrenergic agonist inhaler) whereby inhaler use was four times more likely during the circadian night than day. There were additive influences on asthma from the circadian system plus sleep and other behavioral or environmental effects. Individuals with the lowest average pulmonary function tended to have the largest daily circadian variations and the largest behavioral cycle effects on asthma. When sleep was modeled to occur at night, the summed circadian, behavioral/environmental cycle effects almost perfectly matched the ambulatory data. Thus, the circadian system contributes to the common nocturnal worsening of asthma, implying that internal biological time should be considered for optimal therapy.

Critical Care Pharmacist Attitudes and Perceptions of Neuromuscular Blocker Infusions in ARDS.

BACKGROUND: Current critical care pharmacist (CCP) practices and perceptions related to neuromuscular infusion (NMBI) use for acute respiratory distress syndrome (ARDS) maybe different with the COVID-19 pandemic and the publication of 2020 NMBI practice guidelines. OBJECTIVE: To evaluate CCP practices and perceptions regarding NMBI use for patients with moderate-severe ARDS. METHODS: We developed, tested, and electronically administered a questionnaire (7 parent-, 42 sub-questions) to 409 American College of Clinical Pharmacy (ACCP) Critical Care Practice and Research Network members in 12 geographically diverse states. The questionnaire focused on adults with moderate-severe ARDS (PaO2:FiO2<150) whose causes of dyssynchrony were addressed. Two reminders were sent at 10-day intervals. RESULTS: Respondents [131/409 (32%)] primarily worked in a medical intensive care unit (ICU) 102 (78%). Compared to COVID-negative(-) ARDS patients, COVID positive(+) ARDS patients were twice as likely to receive a NMBI (34 ± 18 vs.16 ± 17%; P < 0.01). Respondents somewhat/strongly agreed a NMBI should be reserved until after trials of deep sedation (112, 86%) or proning (92, 81%) and that NMBI reduced barotrauma (88, 67%), dyssynchrony (87, 66%), and plateau pressure (79, 60%). Few respondents somewhat/strongly agreed that a NMBI should be initiated at ARDS onset (23, 18%) or that NMBI reduced 90-day mortality (12, 10%). Only 2/14 potential NMBI risks [paralysis awareness (101, 82%) and prolonged muscle weakness (84, 68%)] were frequently reported to be of high/very high concern. Multiple NMBI titration targets were assessed as very/extremely important including arterial pH (109, 88%), dyssynchrony (107, 86%), and PaO2: FiO2 ratio (82, 66%). Train-of-four (55, 44%) and BIS monitoring (36, 29%) were deemed less important. Preferred NMBI discontinuation criteria included absence of dysschrony (84, 69%) and use ≥48 hour (72, 59%). CONCLUSIONS AND RELEVANCE: Current critical care pharmacists believe NMBI for ARDS patients are best reserved until after trials of deep sedation or proning; unique considerations exist in COVID+ patients. Our results should be considered when ICU NMBI protocols are being developed and bedside decisions regarding NMBI use in ARDS are being formulated.

Effect of Hydroxychloroquine on Clinical Status at 14 Days in Hospitalized Patients With COVID-19: A Randomized Clinical Trial.

Importance: Data on the efficacy of hydroxychloroquine for the treatment of coronavirus disease 2019 (COVID-19) are needed. Objective: To determine whether hydroxychloroquine is an efficacious treatment for adults hospitalized with COVID-19. Design, Setting, and Participants: This was a multicenter, blinded, placebo-controlled randomized trial conducted at 34 hospitals in the US. Adults hospitalized with respiratory symptoms from severe acute respiratory syndrome coronavirus 2 infection were enrolled between April 2 and June 19, 2020, with the last outcome assessment on July 17, 2020. The planned sample size was 510 patients, with interim analyses planned after every 102 patients were enrolled. The trial was stopped at the fourth interim analysis for futility with a sample size of 479 patients. Interventions: Patients were randomly assigned to hydroxychloroquine (400 mg twice daily for 2 doses, then 200 mg twice daily for 8 doses) (n = 242) or placebo (n = 237). Main Outcomes and Measures: The primary outcome was clinical status 14 days after randomization as assessed with a 7-category ordinal scale ranging from 1 (death) to 7 (discharged from the hospital and able to perform normal activities). The primary outcome was analyzed with a multivariable proportional odds model, with an adjusted odds ratio (aOR) greater than 1.0 indicating more favorable outcomes with hydroxychloroquine than placebo. The trial included 12 secondary outcomes, including 28-day mortality. Results: Among 479 patients who were randomized (median age, 57 years; 44.3% female; 37.2% Hispanic/Latinx; 23.4% Black; 20.1% in the intensive care unit; 46.8% receiving supplemental oxygen without positive pressure; 11.5% receiving noninvasive ventilation or nasal high-flow oxygen; and 6.7% receiving invasive mechanical ventilation or extracorporeal membrane oxygenation), 433 (90.4%) completed the primary outcome assessment at 14 days and the remainder had clinical status imputed. The median duration of symptoms prior to randomization was 5 days (interquartile range [IQR], 3 to 7 days). Clinical status on the ordinal outcome scale at 14 days did not significantly differ between the hydroxychloroquine and placebo groups (median [IQR] score, 6 [4-7] vs 6 [4-7]; aOR, 1.02 [95% CI, 0.73 to 1.42]). None of the 12 secondary outcomes were significantly different between groups. At 28 days after randomization, 25 of 241 patients (10.4%) in the hydroxychloroquine group and 25 of 236 (10.6%) in the placebo group had died (absolute difference, -0.2% [95% CI, -5.7% to 5.3%]; aOR, 1.07 [95% CI, 0.54 to 2.09]). Conclusions and Relevance: Among adults hospitalized with respiratory illness from COVID-19, treatment with hydroxychloroquine, compared with placebo, did not significantly improve clinical status at day 14. These findings do not support the use of hydroxychloroquine for treatment of COVID-19 among hospitalized adults. Trial Registration: ClinicalTrials.gov: NCT04332991.

Semi-quantitative visual assessment of chest radiography is associated with clinical outcomes in critically ill patients.

BACKGROUND: Respiratory pathology is a major driver of mortality in the intensive care unit (ICU), even in the absence of a primary respiratory diagnosis. Prior work has demonstrated that a visual scoring system applied to chest radiographs (CXR) is associated with adverse outcomes in ICU patients with Acute Respiratory Distress Syndrome (ARDS). We hypothesized that a simple, semi-quantitative CXR score would be associated with clinical outcomes for the general ICU population, regardless of underlying diagnosis. METHODS: All individuals enrolled in the Registry of Critical Illness at Brigham and Women's Hospital between June 2008 and August 2018 who had a CXR within 24 h of admission were included. Each patient's CXR was assigned an opacification score of 0-4 in each of four quadrants with the total score being the sum of all four quadrants. Multivariable negative binomial, logistic, and Cox regression, adjusted for age, sex, race, immunosuppression, a history of chronic obstructive pulmonary disease, a history of congestive heart failure, and APACHE II scores, were used to assess the total score's association with ICU length of stay (LOS), duration of mechanical ventilation, in-hospital mortality, 60-day mortality, and overall mortality, respectively. RESULTS: A total of 560 patients were included. Higher CXR scores were associated with increased mortality; for every one-point increase in score, in-hospital mortality increased 10% (OR 1.10, CI 1.05-1.16, p < 0.001) and 60-day mortality increased by 12% (OR 1.12, CI 1.07-1.17, p < 0.001). CXR scores were also independently associated with both ICU length of stay (rate ratio 1.06, CI 1.04-1.07, p < 0.001) and duration of mechanical ventilation (rate ratio 1.05, CI 1.02-1.07, p < 0.001). CONCLUSIONS: Higher values on a simple visual score of a patient's CXR on admission to the medical ICU are associated with increased in-hospital mortality, 60-day mortality, overall mortality, length of ICU stay, and duration of mechanical ventilation.

Hospital Length of Stay With a Proactive Psychiatric Consultation Model in the Medical Intensive Care Unit: A Prospective Cohort Analysis.

BACKGROUND: Previous studies have demonstrated that proactive psychiatric consultation reduces hospital length of stay (LOS) in the general medical setting; however this model has not been studied in the intensive care unit (ICU). OBJECTIVE: To compare outcomes between a conventional consultation model and a proactive psychiatric consultation model. METHODS: Two medical ICUs (MICUs) were randomized to proactive psychiatric consultation vs conventional consultation psychiatric models. Proactive consultation included embedding a psychiatrist into daily MICU team rounds on all patients. In the conventional consultation MICU, psychiatric consultations were activated when deemed necessary. Primary outcomes were hospital LOS and MICU LOS. Secondary outcomes included delirium-coma-free hours and ventilator-free hours. RESULTS: A total of 429 patients were admitted to the proactive consultation MICU; 393 patients were admitted to the conventional consultation MICU. The consultation rate for the intervention group was 24.2% vs 6.1% in the control group (p < 0.001). Time to psychiatric consultation was shorter in the intervention group. Median hospital LOS was 6.92 days, interquartile range 3.70-14.31 in the intervention group vs 7.69 days, interquartile range 3.95-16.21 in the control group (p = 0.113). MICU LOS, delirium-coma-free hours, and ventilator-free hours were not significantly different between the 2 groups. Among the respiratory failure subgroup, hospital LOS was shorter in the intervention vs control group (median 9.46 days, interquartile range 4.95-17.56 vs 12.29 days, interquartile range 6.58-21.10, p = 0.011). CONCLUSIONS: Proactive psychiatric consultation in a MICU was associated with decreased time to consultation among all patients and shorter hospital LOS among patients with respiratory failure.

Compliance With the National SEP-1 Quality Measure and Association With Sepsis Outcomes: A Multicenter Retrospective Cohort Study.

OBJECTIVES: Many septic patients receive care that fails the Centers for Medicare and Medicaid Services' SEP-1 measure, but it is unclear whether this reflects meaningful lapses in care, differences in clinical characteristics, or excessive rigidity of the "all-or-nothing" measure. We compared outcomes in cases that passed versus failed SEP-1 during the first 2 years after the measure was implemented. DESIGN: Retrospective cohort study. SETTING: Seven U.S. hospitals. PATIENTS: Adult patients included in SEP-1 reporting between October 2015 and September 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 851 sepsis cases in the cohort, 281 (33%) passed SEP-1 and 570 (67%) failed. SEP-1 failures had higher rates of septic shock (20% vs 9%; p < 0.001), hospital-onset sepsis (11% vs 4%; p = 0.001), and vague presenting symptoms (46% vs 30%; p < 0.001). The most common reasons for failure were omission of 3- and 6-hour lactate measurements (228/570 failures, 40%). Only 86 of 570 failures (15.1%) had greater than 3-hour delays until broad-spectrum antibiotics. Cases that failed SEP-1 had higher in-hospital mortality rates (18.4% vs 11.0%; odds ratio, 1.82; 95% CI, 1.19-2.80; p = 0.006), but this association was no longer significant after adjusting for differences in clinical characteristics and severity of illness (adjusted odds ratio, 1.36; 95% CI, 0.85-2.18; p = 0.205). Delays of greater than 3 hours until antibiotics were significantly associated with death (adjusted odds ratio, 1.94; 95% CI, 1.04-3.62; p = 0.038), whereas failing SEP-1 for any other reason was not (adjusted odds ratio, 1.10; 95% CI, 0.70-1.72; p = 0.674). CONCLUSIONS: Crude mortality rates were higher in sepsis cases that failed versus passed SEP-1, but there was no difference after adjusting for clinical characteristics and severity of illness. Delays in antibiotic administration were associated with higher mortality but only accounted for a small fraction of SEP-1 failures. SEP-1 may not clearly differentiate between high- and low-quality care, and detailed risk adjustment is necessary to properly interpret associations between SEP-1 compliance and mortality.

Opening the Door: The Experience of Chronic Critical Illness in a Long-Term Acute Care Hospital.

OBJECTIVE: Chronically critically ill patients have recurrent infections, organ dysfunction, and at least half die within 1 year. They are frequently cared for in long-term acute care hospitals, yet little is known about their experience in this setting. Our objective was to explore the understanding and expectations and goals of these patients and surrogates. DESIGN: We conducted semi-structured interviews with chronically critically ill long-term acute care hospital patients or surrogates. Conversations were recorded, transcribed, and analyzed. SETTING: One long-term acute care hospital. SUBJECTS: Chronically critically ill patients, defined by tracheotomy for prolonged mechanical ventilation, or surrogates. INTERVENTION: Semi-structured conversation about quality of life, expectations, and planning for setbacks. MEASUREMENTS AND MAIN RESULTS: A total of 50 subjects (30 patients and 20 surrogates) were enrolled. Thematic analyses demonstrated: 1) poor quality of life for patients; 2) surrogate stress and anxiety; 3) optimistic health expectations; 4) poor planning for medical setbacks; and 5) disruptive care transitions. Nearly 80% of patient and their surrogate decision makers identified going home as a goal; 38% were at home at 1 year. CONCLUSIONS: Our study describes the experience of chronically critically ill patients and surrogates in an long-term acute care hospital and the feasibility of patient-focused research in this setting. Our findings indicate overly optimistic expectations about return home and unmet palliative care needs, suggesting the need for integration of palliative care within the long-term acute care hospital. Further research is also needed to more fully understand the challenges of this growing population of ICU survivors.

Prospective Evaluation of a Multifaceted Intervention to Improve Outcomes in Intensive Care: The Promoting Respect and Ongoing Safety Through Patient Engagement Communication and Technology Study.

OBJECTIVES: Studies comprehensively assessing interventions to improve team communication and to engage patients and care partners in ICUs are lacking. This study examines the effectiveness of a patient-centered care and engagement program in the medical ICU. DESIGN: Prospective intervention study. SETTING: Medical ICUs at large tertiary care center. PATIENTS: Two thousand one hundred five patient admissions (1,030 before and 1,075 during the intervention) from July 2013 to May 2014 and July 2014 to May 2015. INTERVENTIONS: Structured patient-centered care and engagement training program and web-based technology including ICU safety checklist, tools to develop shared care plan, and messaging platform. Patient and care partner access to online portal to view health information, participate in the care plan, and communicate with providers. MEASUREMENTS AND MAIN RESULTS: Primary outcome was aggregate adverse event rate. Secondary outcomes included patient and care partner satisfaction, care plan concordance, and resource utilization. We included 2,105 patient admissions, (1,030 baseline and 1,075 during intervention periods). The aggregate rate of adverse events fell 29%, from 59.0 per 1,000 patient days (95% CI, 51.8-67.2) to 41.9 per 1,000 patient days (95% CI, 36.3-48.3; p < 0.001), during the intervention period. Satisfaction improved markedly from an overall hospital rating of 71.8 (95% CI, 61.1-82.6) to 93.3 (95% CI, 88.2-98.4; p < 0.001) for patients and from 84.3 (95% CI, 81.3-87.3) to 90.0 (95% CI, 88.1-91.9; p < 0.001) for care partners. No change in care plan concordance or resource utilization. CONCLUSIONS: Implementation of a structured team communication and patient engagement program in the ICU was associated with a reduction in adverse events and improved patient and care partner satisfaction.

User-Centered Collaborative Design and Development of an Inpatient Safety Dashboard.

Patient safety remains a key concern in hospital care. This article summarizes the iterative participatory development, features, functions, and preliminary evaluation of a patient safety dashboard for interdisciplinary rounding teams on inpatient medical services. This electronic health record (EHR)-embedded dashboard collects real-time data covering 13 safety domains through web services and applies logic to generate stratified alerts with an interactive check-box function. The technological infrastructure is adaptable to other EHR environments. Surveyed users perceived the tool as highly usable and useful. Integration of the dashboard into clinical care is intended to promote communication about patient safety and facilitate identification and management of safety concerns.

Diagnosing sepsis is subjective and highly variable: a survey of intensivists using case vignettes.

BACKGROUND: Sepsis is the focus of national quality improvement programs and a recent public reporting measure from the Centers for Medicare and Medicaid Services. However, diagnosing sepsis requires interpreting nonspecific signs and can therefore be subjective. We sought to quantify interobserver variability in diagnosing sepsis. METHODS: We distributed five case vignettes of patients with suspected or confirmed infection and organ dysfunction to a sample of practicing intensivists. Respondents classified cases as systemic inflammatory response syndrome, sepsis, severe sepsis, septic shock, or none of the above. Interobserver variability was calculated using Fleiss' κ for the five-level classification, and for answers dichotomized as severe sepsis/septic shock versus not-severe sepsis/septic shock and any sepsis category (sepsis, severe sepsis, or septic shock) versus not-sepsis. RESULTS: Ninety-four physicians completed the survey. Most respondents (88%) identified as critical care specialists; other specialties included pulmonology (39%), anesthesia (19%), surgery (9%), and emergency medicine (9%). Respondents had been in practice for a median of 8 years, and 90% practiced at academic hospitals. Almost all respondents (83%) felt strongly or somewhat confident in their ability to apply the traditional consensus sepsis definitions. However, overall interrater agreement in sepsis diagnoses was poor (Fleiss' κ 0.29). When responses were dichotomized into severe sepsis/septic shock versus not-severe sepsis/septic shock or any sepsis category versus not-sepsis, agreement was still poor (Fleiss' κ 0.23 and 0.18, respectively). Seventeen percent of respondents classified one of the five cases as severe sepsis/septic shock, 27.7% rated two cases, 33.0% respondents rated three cases, 19.2% rated four cases, and 3.2% rated all five cases as severe sepsis/septic shock. Among respondents who felt strongly confident in their ability to use sepsis definitions (n = 45), agreement was no better (Fleiss' κ 0.28 for the five-category classification, and Fleiss' κ 0.21 for the dichotomized severe sepsis/septic shock classification). Cases were felt to be extremely or very realistic in 74% of responses; only 3% were deemed unrealistic. CONCLUSIONS: Diagnosing sepsis is extremely subjective and variable. Objective criteria and standardized methodology are needed to enhance consistency and comparability in sepsis research, surveillance, benchmarking, and reporting.

Integrative "omic" analysis of experimental bacteremia identifies a metabolic signature that distinguishes human sepsis from systemic inflammatory response syndromes.

RATIONALE: Sepsis is a leading cause of morbidity and mortality. Currently, early diagnosis and the progression of the disease are difficult to make. The integration of metabolomic and transcriptomic data in a primate model of sepsis may provide a novel molecular signature of clinical sepsis. OBJECTIVES: To develop a biomarker panel to characterize sepsis in primates and ascertain its relevance to early diagnosis and progression of human sepsis. METHODS: Intravenous inoculation of Macaca fascicularis with Escherichia coli produced mild to severe sepsis, lung injury, and death. Plasma samples were obtained before and after 1, 3, and 5 days of E. coli challenge and at the time of killing. At necropsy, blood, lung, kidney, and spleen samples were collected. An integrative analysis of the metabolomic and transcriptomic datasets was performed to identify a panel of sepsis biomarkers. MEASUREMENTS AND MAIN RESULTS: The extent of E. coli invasion, respiratory distress, lethargy, and mortality was dependent on the bacterial dose. Metabolomic and transcriptomic changes characterized severe infections and death, and indicated impaired mitochondrial, peroxisomal, and liver functions. Analysis of the pulmonary transcriptome and plasma metabolome suggested impaired fatty acid catabolism regulated by peroxisome-proliferator activated receptor signaling. A representative four-metabolite model effectively diagnosed sepsis in primates (area under the curve, 0.966) and in two human sepsis cohorts (area under the curve, 0.78 and 0.82). CONCLUSIONS: A model of sepsis based on reciprocal metabolomic and transcriptomic data was developed in primates and validated in two human patient cohorts. It is anticipated that the identified parameters will facilitate early diagnosis and management of sepsis.

Circulating mitochondrial DNA in patients in the ICU as a marker of mortality: derivation and validation.

BACKGROUND: Mitochondrial DNA (mtDNA) is a critical activator of inflammation and the innate immune system. However, mtDNA level has not been tested for its role as a biomarker in the intensive care unit (ICU). We hypothesized that circulating cell-free mtDNA levels would be associated with mortality and improve risk prediction in ICU patients. METHODS AND FINDINGS: Analyses of mtDNA levels were performed on blood samples obtained from two prospective observational cohort studies of ICU patients (the Brigham and Women's Hospital Registry of Critical Illness [BWH RoCI, n = 200] and Molecular Epidemiology of Acute Respiratory Distress Syndrome [ME ARDS, n = 243]). mtDNA levels in plasma were assessed by measuring the copy number of the NADH dehydrogenase 1 gene using quantitative real-time PCR. Medical ICU patients with an elevated mtDNA level (≥3,200 copies/µl plasma) had increased odds of dying within 28 d of ICU admission in both the BWH RoCI (odds ratio [OR] 7.5, 95% CI 3.6-15.8, p = 1×10(-7)) and ME ARDS (OR 8.4, 95% CI 2.9-24.2, p = 9×10(-5)) cohorts, while no evidence for association was noted in non-medical ICU patients. The addition of an elevated mtDNA level improved the net reclassification index (NRI) of 28-d mortality among medical ICU patients when added to clinical models in both the BWH RoCI (NRI 79%, standard error 14%, p<1×10(-4)) and ME ARDS (NRI 55%, standard error 20%, p = 0.007) cohorts. In the BWH RoCI cohort, those with an elevated mtDNA level had an increased risk of death, even in analyses limited to patients with sepsis or acute respiratory distress syndrome. Study limitations include the lack of data elucidating the concise pathological roles of mtDNA in the patients, and the limited numbers of measurements for some of biomarkers. CONCLUSIONS: Increased mtDNA levels are associated with ICU mortality, and inclusion of mtDNA level improves risk prediction in medical ICU patients. Our data suggest that mtDNA could serve as a viable plasma biomarker in medical ICU patients.

Inflammasome-regulated cytokines are critical mediators of acute lung injury.

RATIONALE: Despite advances in clinical management, there are currently no reliable diagnostic and therapeutic targets for acute respiratory distress syndrome (ARDS). The inflammasome/caspase-1 pathway regulates the maturation and secretion of proinflammatory cytokines (e.g., IL-18). IL-18 is associated with injury in animal models of systemic inflammation. OBJECTIVES: We sought to determine the contribution of the inflammasome pathway in experimental acute lung injury and human ARDS. METHODS: We performed comprehensive gene expression profiling on peripheral blood from patients with critical illness. Gene expression changes were assessed using real-time polymerase chain reaction, and IL-18 levels were measured in the plasma of the critically ill patients. Wild-type mice or mice genetically deficient in IL-18 or caspase-1 were mechanically ventilated using moderate tidal volume (12 ml/kg). Lung injury parameters were assessed in lung tissue, serum, and bronchoalveolar lavage fluid. MEASUREMENTS AND MAIN RESULTS: In mice, mechanical ventilation enhanced IL-18 levels in the lung, serum, and bronchoalveolar lavage fluid. IL-18-neutralizing antibody treatment, or genetic deletion of IL-18 or caspase-1, reduced lung injury in response to mechanical ventilation. In human patients with ARDS, inflammasome-related mRNA transcripts (CASP1, IL1B, and IL18) were increased in peripheral blood. In samples from four clinical centers, IL-18 was elevated in the plasma of patients with ARDS (sepsis or trauma-induced ARDS) and served as a novel biomarker of intensive care unit morbidity and mortality. CONCLUSIONS: The inflammasome pathway and its downstream cytokines play critical roles in ARDS development.

Correlates of individual participation in boundary patrols by male chimpanzees.

Group territory defence poses a collective action problem: individuals can free-ride, benefiting without paying the costs. Individual heterogeneity has been proposed to solve such problems, as individuals high in reproductive success, rank, fighting ability or motivation may benefit from defending territories even if others free-ride. To test this hypothesis, we analysed 30 years of data from chimpanzees (Pan troglodytes) in the Kasekela community, Gombe National Park, Tanzania (1978-2007). We examined the extent to which individual participation in patrols varied according to correlates of reproductive success (mating rate, rank, age), fighting ability (hunting), motivation (scores from personality ratings), costs of defecting (the number of adult males in the community) and gregariousness (sighting frequency). By contrast to expectations from collective action theory, males participated in patrols at consistently high rates (mean ± s.d. = 74.5 ± 11.1% of patrols, n = 23 males). The best predictors of patrol participation were sighting frequency, age and hunting participation. Current and former alpha males did not participate at a higher rate than males that never achieved alpha status. These findings suggest that the temptation to free-ride is low, and that a mutualistic mechanism such as group augmentation may better explain individual participation in group territorial behaviour. This article is part of the theme issue 'Intergroup conflict across taxa'.

Predicting hospitalization of COVID-19 positive patients using clinician-guided machine learning methods.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) is a resource-intensive global pandemic. It is important for healthcare systems to identify high-risk COVID-19-positive patients who need timely health care. This study was conducted to predict the hospitalization of older adults who have tested positive for COVID-19. METHODS: We screened all patients with COVID test records from 11 Mass General Brigham hospitals to identify the study population. A total of 1495 patients with age 65 and above from the outpatient setting were included in the final cohort, among which 459 patients were hospitalized. We conducted a clinician-guided, 3-stage feature selection, and phenotyping process using iterative combinations of literature review, clinician expert opinion, and electronic healthcare record data exploration. A list of 44 features, including temporal features, was generated from this process and used for model training. Four machine learning prediction models were developed, including regularized logistic regression, support vector machine, random forest, and neural network. RESULTS: All 4 models achieved area under the receiver operating characteristic curve (AUC) greater than 0.80. Random forest achieved the best predictive performance (AUC = 0.83). Albumin, an index for nutritional status, was found to have the strongest association with hospitalization among COVID positive older adults. CONCLUSIONS: In this study, we developed 4 machine learning models for predicting general hospitalization among COVID positive older adults. We identified important clinical factors associated with hospitalization and observed temporal patterns in our study cohort. Our modeling pipeline and algorithm could potentially be used to facilitate more accurate and efficient decision support for triaging COVID positive patients.

Physicians' attitudes and perceptions of neuromuscular blocker infusions in ARDS.

PURPOSE: The perceptions and practices of ICU physicians regarding initiating neuromuscular blocker infusions (NMBI) in acute respiratory distress syndrome (ARDS) may not be evidence-based amidst the surge of severe ARDS during the SARS-CoV-2 pandemic and new practice guidelines. We identified ICU physicians' perspectives and practices regarding NMBI use in adults with moderate-severe ARDS. MATERIALS AND METHODS: After extensive development and testing, an electronic survey was distributed to 342 ICU physicians from three geographically-diverse U.S. health systems(n = 12 hospitals). RESULTS: The 173/342 (50.5%) respondents (75% medical) somewhat/strongly agreed a NMBI should be reserved until: after a trial of deep sedation (142, 82%) or proning (59, 34%) and be dose-titrated based on train-of-four monitoring (107, 62%). Of 14 potential NMBI risks, 2 were frequently reported to be of high/very high concern: prolonged muscle weakness with steroid use (135, 79%) and paralysis awareness due to inadequate sedation (114, 67%). Absence of dyssychrony (93, 56%) and use ≥48 h (87, 53%) were preferred NMBI stopping criteria. COVID-19 + ARDS patients were twice as likely to receive a NMBI (56 ± 37 vs. 28 ± 19%, p < 0.01). CONCLUSIONS: Most intensivists agreed NMBI in ARDS should be reserved until after a deep sedation trial. Stopping criteria remain poorly defined. Unique considerations exist regarding the role of paralysis in COVID-19+ ARDS.

Comparison of a Voluntary Safety Reporting System to a Global Trigger Tool for Identifying Adverse Events in an Oncology Population.

OBJECTIVE: There is a lack of research on adverse event (AE) detection in oncology patients, despite the propensity for iatrogenic harm. Two common methods include voluntary safety reporting (VSR) and chart review tools, such as the Institute for Healthcare Improvement's Global Trigger Tool (GTT). Our objective was to compare frequency and type of AEs detected by a modified GTT compared with VSR for identifying AEs in oncology patients in a larger clinical trial. METHODS: Patients across 6 oncology units (from July 1, 2013, through May 29, 2015) were randomly selected. Retrospective chart reviews were conducted by a team of nurses and physicians to identify AEs using the GTT. The VSR system was queried by the department of quality and safety of the hospital. Adverse event frequencies, type, and harm code for both methods were compared. RESULTS: The modified GTT detected 0.90 AEs per patient (79 AEs in 88 patients; 95% [0.71-1.12] AEs per patient) that were predominantly medication AEs (53/79); more than half of the AEs caused harm to the patients (41/79, 52%), but only one quarter were preventable (21/79; 27%). The VSR detected 0.24 AEs per patient (21 AEs in 88 patients; 95% [0.15-0.37] AEs per patient), a large plurality of which were medication/intravenous related (8/21); more than half did not cause harm (70%). Only 2% of the AEs (2/100) were detected by both methods. CONCLUSIONS: Neither the modified GTT nor the VSR system alone is sufficient for detecting AEs in oncology patient populations. Further studies exploring methods such as automated AE detection from electronic health records and leveraging patient-reported AEs are needed.

Serial Perioperative Assessment of Free Flap Perfusion With Laser Angiography.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Reconstruction with microvascular free flaps is quite predictable but excessive fluids intraoperatively and excessive use of vasopressors have been implicated in postoperative complications. However, vasopressors assist in limiting fluid administration and counteract vasodilatory effects of general anesthetics, while maintaining proper intravascular volume. This is of paramount importance during surgery to ensure adequate tissue and organ perfusion. The purpose of this study is to quantify perfusion changes in free flaps at specific time points during peri- and postoperative periods, incorporating SPY technology. METHODS: A prospective study of patients who underwent free flap reconstruction was conducted (n = 9), using SPY laser angiography with indocyanine green to assess effects of general anesthetics and vasopressors on flap perfusion. Free flaps were evaluated prior to pedicle division, after inset and anastomosis, and in the immediate postoperative setting. Mean perfusion, mean arterial pressure, total operative time, fluid shifts, and vasopressor use were recorded. Data were analyzed with univariate and multivariable analyses. RESULTS: Those with major complications in this cohort, on average received less vasopressors, had shorter operation times and less blood loss, however, they received more fluids intraoperatively. CONCLUSION: Changes in mean perfusion to the free flap during the intraoperative and immediate postoperative period are nominal.

Feasibility of extracorporeal membrane oxygenation cardiopulmonary resuscitation by low volume centers in Belgium.

OBJECTIVE: To assess the feasibility of delivering extracorporeal cardiopulmonary resuscitation (ECPR) in refractory out-of-hospital cardiac arrests (OHCA) by low volume extracorporeal membrane oxygenation (ECMO) centers and to explore pre-ECPR predictors of survival. METHODS: Between 2016 and 2020, we studied 21 ECPR patients admitted in 2 tertiary ECMO centers in Liège, Belgium. Our ECPR protocol was based on 6 prehospital criteria (no flow < 3 minutes, low flow < 60 minutes, initial shockable rhythm, end-tidal CO2 > 15 mmHg, age < 65 years, and absence of comorbidities). A dedicated training, prehospital checklist and call number for 24/7 ECMO team assistance were implemented. Hemodynamics and blood gases on admission also were assessed. RESULTS: Twenty-one (28%) out of 75 refractory OHCA patients referred were treated by ECPR, with a hospital survival rate of 43% (n = 9/21), comparable to ECPR results from the international extracorporeal life support organization registry. Transient return of spontaneous circulation before ECPR (89% in survivors vs 17% in non-survivors, P = 0.002) and higher initial serum bicarbonate (med [P25-P75] 14.0 [10.6-15.2] vs 7.5 [3.7-10.5] mmol/L, P = 0.019) or lower initial base deficit (14.9 [11.9-18.2] vs 21.6 [17.9-28.9] mmol/L, P = 0.039) were associated with a more favorable outcome. CONCLUSION: In low volume ECMO centers, the implementation of a specific ECPR protocol for refractory OHCA patients is feasible and provides potential clinical benefit. Highly selective inclusion criteria seem essential to select candidates for ECPR. Initial serum bicarbonate and base deficit integrating cumulative cell failure may be relevant pre-ECMO prognostic factors and require larger-scale evaluation.