Faculty Bibliography

BACKGROUND:Despite evidence associating inflammatory biomarkers with worse outcomes in hospitalized adults with COVID-19, trials of immunomodulatory therapies have met with mixed results, likely due in part to biological heterogeneity of participants. Latent class analysis (LCA) of clinical and protein biomarker data has identified two subtypes of non-COVID acute respiratory distress syndrome (ARDS) with different clinical outcomes and treatment responses. We studied biological heterogeneity and clinical outcomes in a multi-institutional platform randomized controlled trial of adults with severe COVID-19 hypoxemic respiratory failure (I-SPY COVID). METHODS:Clinical and plasma protein biomarker data were analyzed from 400 trial participants enrolled from September 2020 until October 2021 with severe COVID-19 requiring ≥ 6 L/min supplemental oxygen. Seventeen hypothesis-directed protein biomarkers were measured at enrollment using multiplex Luminex panels or single analyte enzyme linked immunoassay methods (ELISA). Biomarkers and clinical variables were used to test for latent subtypes and longitudinal biomarker changes by subtype were explored. A validated parsimonious model using interleukin-8, bicarbonate, and protein C was used for comparison with non-COVID hyper- and hypo-inflammatory ARDS subtypes. RESULTS:Average participant age was 60 ± 14 years; 67% were male, and 28-day mortality was 25%. At trial enrollment, 85% of participants required high flow oxygen or non-invasive ventilation, and 97% were receiving dexamethasone. Several biomarkers of inflammation (IL-6, IL-8, IL-10, sTNFR-1, TREM-1), epithelial injury (sRAGE), and endothelial injury (Ang-1, thrombomodulin) were associated with 28- and 60-day mortality. Two latent subtypes were identified. Subtype 2 (27% of participants) was characterized by persistent derangements in biomarkers of inflammation, endothelial and epithelial injury, and disordered coagulation and had twice the mortality rate compared with Subtype 1. Only one person was classified as hyper-inflammatory using the previously validated non-COVID ARDS model. CONCLUSIONS:We discovered evidence of two novel biological subtypes of severe COVID-19 with significantly different clinical outcomes. These subtypes differed from previously established hyper- and hypo-inflammatory non-COVID subtypes of ARDS. Biological heterogeneity may explain inconsistent findings from trials of hospitalized patients with COVID-19 and guide treatment approaches.

Persistent infections, whether viral, bacterial or parasitic, including Helicobacter pylori infection, have been implicated in non-communicable diseases, including dementia and other neurodegenerative diseases. In this cross-sectional study, data on 635 cognitively normal participants from the UK Biobank study (2006-21, age range: 40-70 years) were used to examine whether H. pylori seropositivity (e.g. presence of antibodies), serointensities of five H. pylori antigens and a measure of total persistent infection burden were associated with selected brain volumetric structural MRI (total, white, grey matter, frontal grey matter (left/right), white matter hyperintensity as percent intracranial volume and bi-lateral sub-cortical volumes) and diffusion-weighted MRI measures (global and tract-specific bi-lateral fractional anisotropy and mean diffusivity), after an average 9-10 years of lag time. Persistent infection burden was calculated as a cumulative score of seropositivity for over 20 different pathogens. Multivariable-adjusted linear regression analyses were conducted, whereby selected potential confounders (all measures) and intracranial volume (sub-cortical volumes) were adjusted, with stratification by Alzheimer's disease polygenic risk score tertile when exposures were H. pylori antigen serointensities. Type I error was adjusted to 0.007. We report little evidence of an association between H. pylori seropositivity and persistent infection burden with various volumetric outcomes (P > 0.007, from multivariable regression models), unlike previously reported in past research. However, H. pylori antigen serointensities, particularly immunoglobulin G against the vacuolating cytotoxin A, GroEL and outer membrane protein antigens, were associated with poorer tract-specific white matter integrity (P < 0.007), with outer membrane protein serointensity linked to worse outcomes in cognition-related tracts such as the external capsule, the anterior limb of the internal capsule and the cingulum, specifically at low Alzheimer's disease polygenic risk. Vacuolating cytotoxin A serointensity was associated with greater white matter hyperintensity volume among individuals with mid-level Alzheimer's disease polygenic risk, while among individuals with the highest Alzheimer's disease polygenic risk, the urease serointensity was consistently associated with reduced bi-lateral caudate volumes and the vacuolating cytotoxin A serointensity was linked to reduced right putamen volume (P < 0.007). Outer membrane protein and urease were associated with larger sub-cortical volumes (e.g. left putamen and right nucleus accumbens) at middle Alzheimer's disease polygenic risk levels (P < 0.007). Our results shed light on the relationship between H. pylori seropositivity, H. pylori antigen levels and persistent infection burden with brain volumetric structural measures. These data are important given the links between infectious agents and neurodegenerative diseases, including Alzheimer's disease, and can be used for the development of drugs and preventive interventions that would reduce the burden of those diseases.

BACKGROUND:CC-115, a dual mTORC1/2 and DNA-PK inhibitor, has promising antitumour activity when combined with androgen receptor (AR) inhibition in pre-clinical models. METHODS:Phase 1b multicentre trial evaluating enzalutamide with escalating doses of CC-115 in AR inhibitor-naive mCRPC patients (n = 41). Primary endpoints were safety and RP2D. Secondary endpoints included PSA response, time-to-PSA progression, and radiographic progression. RESULTS:Common adverse effects included rash (31.7% Grades 1-2 (Gr); 31.7% Gr 3), pruritis (43.9% Gr 1-2), diarrhoea (37% Gr 1-2), and hypertension (17% Gr 1-2; 9.8% Gr 3). CC-115 RP2D was 5 mg twice a day. In 40 evaluable patients, 80% achieved ≥50% reduction in PSA (PSA50), and 58% achieved ≥90% reduction in PSA (PSA90) by 12 weeks. Median time-to-PSA progression was 14.7 months and median rPFS was 22.1 months. Stratification by PI3K alterations demonstrated a non-statistically significant trend towards improved PSA50 response (PSA50 of 94% vs. 67%, p = 0.08). Exploratory pre-clinical analysis suggested CC-115 inhibited mTOR pathway strongly, but may be insufficient to inhibit DNA-PK at RP2D. CONCLUSIONS:The combination of enzalutamide and CC-115 was well tolerated. A non-statistically significant trend towards improved PSA response was observed in patients harbouring PI3K pathway alterations, suggesting potential predictive biomarkers of response to a PI3K/AKT/mTOR pathway inhibitor. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov identifier: NCT02833883.

BACKGROUND:The last national estimates of US ICU physician staffing are 25 years old and lack information about interprofessional teams. RESEARCH QUESTION/OBJECTIVE:How are US adult ICUs currently staffed? STUDY DESIGN AND METHODS/METHODS:We conducted a cross-sectional survey (May 4, 2022-February 2, 2023) of adult ICU clinicians (targeting nurse/physician leadership) contacted using 2020 American Hospital Association (AHA) database information and, secondarily, through professional organizations. The survey included questions about interprofessional ICU staffing availability and roles at steady state (pre-COVID-19). We linked survey data to hospital data in the AHA database to create weighted national estimates by extrapolating ICU staffing data to nonrespondent hospitals based on hospital characteristics. RESULTS:The cohort consisted of 596 adult ICUs (response rates: AHA contacts: 2.1%; professional organizations: unknown) with geographic diversity and size variability (median, 20 beds; interquartile range, 12-25); most cared for mixed populations (414 [69.5%]), yet medical (55 [9.2%]), surgical (70 [11.7%]), and specialty (57 [9.6%]) ICUs were well represented. A total of 554 (93.0%) had intensivists available, with intensivists covering all patients in 75.6% of these and onsite 24 h/d in one-half (53.3% weekdays; 51.8% weekends). Of all ICUs, 69.8% had physicians-in-training and 77.7% had nurse practitioners/physician assistants. For patients on mechanical ventilation, nurse to patient ratios were 1:2 in 89.6% of ICUs. Clinical pharmacists were available in 92.6%, and respiratory therapists were available in 98.8%. We estimated 85.1% (95% CI, 85.7%-84.5%) of hospitals nationally had ICUs with intensivists, 51.6% (95% CI, 50.6%-52.5%) had physicians-in-training, 72.1% (95% CI, 71.3%-72.9%) had nurse practitioners/physician assistants, 98.5% (95% CI, 98.4%-98.7%) had respiratory therapists, and 86.9% (95% CI, 86.4%-87.4%) had clinical pharmacists. For patients on mechanical ventilation, 86.4% (95% CI, 85.8%-87.0%) used 1:2 nurses/patients. INTERPRETATION/CONCLUSIONS:We found that intensivist presence in adult US ICUs has greatly increased over 25 years. Intensivists, respiratory therapists, and clinical pharmacists are commonly available, and each nurse usually provides care for two patients on mechanical ventilation. However, team composition and workload vary.

RATIONALE & OBJECTIVE/UNASSIGNED:This study aimed to assess the effect of exposure to organic pollutants in adults with chronic kidney disease (CKD). STUDY DESIGN/UNASSIGNED:This was a cross-sectional and longitudinal analysis. SETTING AND PARTICIPANTS/UNASSIGNED:Forty adults enrolled in the Chronic Renal Insufficiency Cohort (CRIC). EXPOSURES/UNASSIGNED:Exposure at baseline and longitudinally to various organic chemical pollutants. OUTCOMES/UNASSIGNED:The outcomes were as follows: death; composite of congestive heart failure, myocardial infarction, and stroke; event-free survival from kidney failure or ≥50% decline in estimated glomerular filtration rate (eGFR); and longitudinal trajectory of eGFR. ANALYTICAL APPROACH/UNASSIGNED:We used high-performance liquid chromatography with tandem mass spectrometry to measure urinary concentrations of bisphenols, phthalates, organophosphate pesticides, polycyclic aromatic hydrocarbons, melamine, and cyanuric acid at years 1, 3, and 5 after enrollment in the CRIC. Univariate and multivariable logistic regression were used to examine the association of individual compounds and classes of pollutants with the outcomes. The Cox proportional hazards model and Kaplan-Meier method were used to calculate hazard ratios and 95% CIs for each class of pollutants. RESULTS/UNASSIGNED:and 0.58 mg/g, respectively. Of 52 compounds assayed, 30 were detectable in ≥50% of participants. Urinary chemical concentrations were comparable in patients with CKD and healthy individuals from contemporaneous National Health and Nutrition Examination Survey cohorts. Phthalates were the only class with a trend toward higher exposure in patients with CKD. There was an inverse relationship between exposure and the eGFR slopes for bisphenol F, mono-(3-carboxypropyl) phthalate, mono-benzyl phthalate, mono-[2-(carboxymethyl)hexyl] phthalate, and melamine. There were no associations between organic pollutant exposure and cardiovascular outcomes. LIMITATIONS/UNASSIGNED:Small sample size, evaluation of single rather than combined exposures. CONCLUSIONS/UNASSIGNED:Simultaneous measurement of multiple organic pollutants in adults with CKD is feasible. Exposure levels are comparable with healthy individuals. Select contaminants, especially in the phthalate class, may be associated with more rapid deterioration in kidney function.

OBJECTIVE/UNASSIGNED:The objective of this review is to discuss acid-base physiology, describe the essential steps for interpreting an arterial blood gas and relevant laboratory tests, and review the 4 distinct types of acid-base disorders. DATA SOURCES/UNASSIGNED:A comprehensive literature search and resultant bibliography review of PubMed from inception through March 7, 2023. STUDY SELECTION AND DATA EXTRACTION/UNASSIGNED:Relevant English-language articles were extracted and evaluated. DATA SYNTHESIS/UNASSIGNED:Critically ill patients are prone to significant acid-base disorders that can adversely affect clinical outcomes. Assessing these acid-base abnormalities can be complex because of dynamic aberrations in plasma proteins, electrolytes, extracellular volume, concomitant therapies, and use of mechanical ventilation. This article provides a systematic approach to acid-base abnormalities which is necessary to facilitate prompt identification of acid-base disturbances and prevent untoward morbidity and mortality. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE/UNASSIGNED:Many acid-base disorders result from medication therapy or are treated with medications. Pharmacists are uniquely poised as the medication experts on the multidisciplinary team to assist with acid-base assessments in the context of pharmacotherapy. CONCLUSION/UNASSIGNED:The use of a systematic approach to address acid-base disorders can be performed by all pharmacists to improve pharmacotherapy and optimize patient outcomes.

PURPOSE:This study aimed to survey critical care clinicians and characterize their perception of antimicrobial dosing strategies in patients receiving extracorporeal membrane oxygenation (ECMO). METHODS:International, cross-sectional survey distributed to members of the Society of Critical Care Medicine in October 2022. RESULTS:Respondents were primarily physicians (45%), with 92% practicing in North America. Ninety-seven percent of respondents reported antimicrobial dosing in critically ill patients to be challenging, due to physiological derangements seen in the patient population. Eighty-seven percent reported consideration of physicochemical drug properties when dosing antimicrobials in ECMO-supported patients, with lipophilicity (83%) and degree of protein binding (74%) being the two most common. Respondents' approach to antimicrobial dosing strategies did not significantly differ in critically ill ECMO-supported patients, compared to patients with equal severity of illness not receiving ECMO support. CONCLUSION:Approaches to antimicrobial dosing strategies do not significantly differ among respondents between critically ill patients on ECMO support, compared to patients with equal severity of illness not receiving ECMO support. These findings were unexpected considering the added physiologic complexity of the ECMO circuit to critically ill adult patients and the need for well designed and adequately powered studies to inform empiric dosing guidance for ECMO-supported patients.

People living with HIV (PLH) who live in rural areas of the United States (US) face more challenges to obtaining medical care and suffer higher mortality rates compared to non-rural PLH. Compared with younger PLH, older PLH (age 50+) also face additional challenges to maintaining their health and wellbeing. Despite the heightened barriers to receiving care and remaining adherent to treatment among older rural PLH, few interventions to increase viral suppression and improve quality of life exist for this population. We pilot-tested four remotely-delivered interventions-group-based social support, group-based stigma-reduction, individual strengths-based case management, and individual technology detailing-aimed to improve care engagement and quality of life in rural older PLH in the southern US. Participants (N = 61, M_age = 58, 75% male) completed surveys and self-collected blood specimens at baseline and 3 months; in between, they were randomized to 0-4 interventions. We assessed feasibility, acceptability, and preliminary impact on medication adherence, viral suppression, quality of life, depressive symptoms, and hypothesized mediating mechanisms. More than 80% participated in assigned intervention(s), and 84% completed the study. Interventions were highly acceptable to participants, with more than 80% reporting they would recommend interventions to peers. More than 80% found the social support and case management interventions to be relevant and enjoyable. We found promising preliminary impact of interventions on quality of life, medication adherence, depressive symptoms, internalized stigma, and loneliness. Remotely-delivered interventions targeting rural older PLH are feasible to conduct and acceptable to participants. Larger scale study of these interventions is warranted.

Suicide screening is critical in pediatric emergency departments (EDs). Behavioral measures of suicide risk may complement self-report measures. The current study examines suicide-specific behavioral measures and tests their potential short-term within-person effects among respondents, ability to discriminate future suicide attempt from suicidal ideation, and translation into interpretable categorical composite scores. The sample included 167 youth (10-17 years), presenting for suicide-related reasons to a pediatric psychiatric ED. During their ED visit, participants completed the Death/Life Implicit Association Test (IAT) and the Suicide Stroop Task. Recurrent suicidal thoughts and attempts were assessed within 6 months of the ED visit via medical records and email surveys. Youth displayed a decrease in the levels of distress and self-injurious desires (negative mood, desire to hurt themselves, and desire to die) after completing the behavioral tasks. The Death/Life IAT prospectively differentiated with 68% accuracy between youth who attempted suicide after their ED visit and those who had suicidal ideation but no attempt, p = 0.04, OR = 5.65, although this effect became marginally significant after controlling for self-report and demographic covariates. Neither the Suicide Stroop Task, nor the categorical composite scores predicted suicide attempts, ps = 0.08-0.87, ORs = 0.96-3.95. Behavioral measures of suicide risk administered in the ED do not appear to increase distress or self-injurious desires. They may be able to distinguish those who go on to attempt suicide (vs. consider suicide) within six months after discharge.