Validation of SeptiCyte RAPID to Discriminate Sepsis from Non-Infectious Systemic Inflammation

(1) Background: SeptiCyte RAPID is a molecular test for discriminating sepsis from non-infectious systemic inflammation, and for estimating sepsis probabilities. The objective of this study was the clinical validation of SeptiCyte RAPID, based on testing retrospectively banked and prospectively collected patient samples. (2) Methods: The cartridge-based SeptiCyte RAPID test accepts a PAXgene blood RNA sample and provides sample-to-answer processing in ~1 h. The test output (SeptiScore, range 0-15) falls into four interpretation bands, with higher scores indicating higher probabilities of sepsis. Retrospective (N = 356) and prospective (N = 63) samples were tested from adult patients in ICU who either had the systemic inflammatory response syndrome (SIRS), or were suspected of having/diagnosed with sepsis. Patients were clinically evaluated by a panel of three expert physicians blinded to the SeptiCyte test results. Results were interpreted under either the Sepsis-2 or Sepsis-3 framework. (3) Results: Under the Sepsis-2 framework, SeptiCyte RAPID performance for the combined retrospective and prospective cohorts had Areas Under the ROC Curve (AUCs) ranging from 0.82 to 0.85, a negative predictive value of 0.91 (sensitivity 0.94) for SeptiScore Band 1 (score range 0.1-5.0; lowest risk of sepsis), and a positive predictive value of 0.81 (specificity 0.90) for SeptiScore Band 4 (score range 7.4-15; highest risk of sepsis). Performance estimates for the prospective cohort ranged from AUC 0.86-0.95. For physician-adjudicated sepsis cases that were blood culture (+) or blood, urine culture (+)(+), 43/48 (90%) of SeptiCyte scores fell in Bands 3 or 4. In multivariable analysis with up to 14 additional clinical variables, SeptiScore was the most important variable for sepsis diagnosis. A comparable performance was obtained for the majority of patients reanalyzed under the Sepsis-3 definition, although a subgroup of 16 patients was identified that was called septic under Sepsis-2 but not under Sepsis-3. (4) Conclusions: This study validates SeptiCyte RAPID for estimating sepsis probability, under both the Sepsis-2 and Sepsis-3 frameworks, for hospitalized patients on their first day of ICU admission.

Updated guidance on the management of COVID-19: from an American Thoracic Society/European Respiratory Society coordinated International Task Force (29 July 2020)

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome-coronavirus-2. Consensus suggestions can standardise care, thereby improving outcomes and facilitating future research.

METHODS

An International Task Force was composed and agreement regarding courses of action was measured using the Convergence of Opinion on Recommendations and Evidence (CORE) process. 70% agreement was necessary to make a consensus suggestion.

RESULTS

The Task Force made consensus suggestions to treat patients with acute COVID-19 pneumonia with remdesivir and dexamethasone but suggested against hydroxychloroquine except in the context of a clinical trial; these are revisions of prior suggestions resulting from the interim publication of several randomised trials. It also suggested that COVID-19 patients with a venous thromboembolic event be treated with therapeutic anticoagulant therapy for 3 months. The Task Force was unable to reach sufficient agreement to yield consensus suggestions for the post-hospital care of COVID-19 survivors. The Task Force fell one vote shy of suggesting routine screening for depression, anxiety and post-traumatic stress disorder.

CONCLUSIONS

The Task Force addressed questions related to pharmacotherapy in patients with COVID-19 and the post-hospital care of survivors, yielding several consensus suggestions. Management options for which there is insufficient agreement to formulate a suggestion represent research priorities.

Time-Limited Trials Among Critically Ill Patients With Advanced Medical Illnesses to Reduce Nonbeneficial Intensive Care Unit Treatments: Protocol for a Multicenter Quality Improvement Study

Background

Invasive intensive care unit (ICU) treatments for patients with advanced medical illnesses and poor prognoses may prolong suffering with minimal benefit. Unfortunately, the quality of care planning and communication between clinicians and critically ill patients and their families in these situations are highly variable, frequently leading to overutilization of invasive ICU treatments. Time-limited trials (TLTs) are agreements between the clinicians and the patients and decision makers to use certain medical therapies over defined periods of time and to evaluate whether patients improve or worsen according to predetermined clinical parameters. For patients with advanced medical illnesses receiving aggressive ICU treatments, TLTs can promote effective dialogue, develop consensus in decision making, and set rational boundaries to treatments based on patients’ goals of care.

Objective

The aim of this study will be to examine whether a multicomponent quality-improvement strategy that uses protocoled TLTs as the default ICU care-planning approach for critically ill patients with advanced medical illnesses will decrease duration and intensity of nonbeneficial ICU care without changing hospital mortality.

Methods

This study will be conducted in medical ICUs of three public teaching hospitals in Los Angeles County. In Aim 1, we will conduct focus groups and semistructured interviews with key stakeholders to identify facilitators and barriers to implementing TLTs among ICU patients with advanced medical illnesses. In Aim 2, we will train clinicians to use protocol-enhanced TLTs as the default communication and care-planning approach in patients with advanced medical illnesses who receive invasive ICU treatments. Eligible patients will be those who the treating ICU physicians consider to be at high risk for nonbeneficial treatments according to guidelines from the Society of Critical Care Medicine. ICU physicians will be trained to use the TLT protocol through a curriculum of didactic lectures, case discussions, and simulations utilizing actors as family members in role-playing scenarios. Family meetings will be scheduled by trained care managers. The improvement strategy will be implemented sequentially in the three participating hospitals, and outcomes will be evaluated using a before-and-after study design. Key process outcomes will include frequency, timing, and content of family meetings. The primary clinical outcome will be ICU length of stay. Secondary outcomes will include hospital length of stay, days receiving life-sustaining treatments (eg, mechanical ventilation, vasopressors, and renal replacement therapy), number of attempts at cardiopulmonary resuscitation, frequency of invasive ICU procedures, and disposition from hospitalization.

Results

The study began in August 2017. The implementation of interventions and data collection were completed at two of the three hospitals. As of September 2019, the study was at the postintervention stage at the third hospital. We have completed focus groups with physicians at each medical center (N=29) and interviews of family members and surrogate decision makers (N=18). The study is expected to be completed in the first quarter of 2020, and results are expected to be available in mid-2020.

Conclusions

The successful completion of the aims in this proposal may identify a systematic approach to improve communication and shared decision making and to reduce nonbeneficial invasive treatments for ICU patients with advanced medical illnesses.

International Registered Report Identifier (IRRID)

DERR1-10.2196/16301

Developmental pathways and specification of intrapulmonary stem cells

Tissues have the capacity to maintain a homeostatic balance between wear-and-tear and regeneration. Repair of non-lethal injury also activates cell proliferation to repopulate the injured sites with appropriate cell types and to restore function. Although controversial, the source of the material appears to be at least partly from pools of unique, multipotent stem cells that reside in specialized locations referred to as "niches." Molecular interactions between the niche and the intracellular factors within stem cells are crucial in maintaining stem cell functions, particularly the balance between self-renewal and differentiation. Many of the mediators of the stem cell-niche interactions are similar or identical to those that control developmental pathways during organogenesis. In this review, we present a systematic discussion and evaluation of the relevant literature with a focused emphasis on three primary signaling pathways, WNT, SHH and BMP with potentially overlapping roles during both development and stem cell maintenance.

Modulation of ion conductance and active transport by TGF-beta 1 in alveolar epithelial cell monolayers

Transforming growth factor-beta1 (TGF-beta 1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-beta 1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells. Exposure to TGF-beta 1 (0.1-100 pM) from day 0 resulted in a concentration- and time-dependent decrease in transepithelial resistance (Rt) and increase in short-circuit current (Isc). Apical amiloride or basolateral ouabain on day 6 inhibited Isc by 80 and 100%, respectively. Concurrent increases in expression of Na+-K+-ATPase alpha 1- and beta 1-subunits were observed in TGF-beta 1-treated monolayers. No change in the alpha-subunit of the rat epithelial sodium channel (alpha-rENaC) was seen. Exposure of confluent monolayers to TGF-beta 1 from day 4 resulted in an initial decrease in Rt within 6 h, followed by an increase in Isc over 72-96 h. These results demonstrate that TGF-beta 1 modulates ion conductance and active transport characteristics of the alveolar epithelium, associated with increased Na+-K+-ATPase, but without a change in alpha-rENaC.

Lateral tibial avulsion fractures and disruptions to the anterior cruciate ligament. A clinical study of their incidence and correlation

Avulsion fractures of the lateral tibial plateau, known as the lateral capsular sign, are increasingly associated with anterior cruciate ligament (ACL) ruptures. This phenomenon, known as the Ségond fracture, is a bony avulsion of the menisco-tibial ligament. Stress, which can lead to an avulsion of this kind, almost always occurs during knee flexion and internal tibial rotation, and in most cases only after damage to the primary ACL stabilizer. Examination of 151 ACL ruptures revealed a Ségond fracture in 9% of patients. Nearly all were caused by sports injuries and, understandably, the accident mechanism always included knee flexion and internal rotation of the tibial. In a similarly large number of other knee injuries without damage to the ACL, only one case of a Ségond fracture was found. This phenomenon, which is easy to detect by radiograph, can thus be regarded as a strong indication of the presence of a ligament injury.

Changes in serum angiotensin-converting enzyme during cardiopulmonary bypass in humans

In 15 male patients 45 to 74 yr of age, we measured angiotensin-converting enzyme (ACE) activity during and after cardiopulmonary bypass (all values were corrected for hemodilution occurring during surgery). Baseline ACE measurements (prior to onset of bypass) were 17.6 +/- 6.7 nmol of hippuric acid formed/min/ml (mean +/- SD). After the lung was isolated, serum ACE activity fell rapidly (half-clearance time, 39.5 min) and after 20 min during bypass reached a new steady state 33% below baseline values. Within 10 min of lung reperfusion, serum ACE rose to 90% of baseline values. ACE activity fell (half-clearance time, 198.3 min) and was again significantly below baseline for the period from 60 to 300 min after the end of cardiopulmonary bypass. Serum ACE activity had again returned to baseline when assessed 24 h after surgery; ACE activity in serum fluctuates rapidly, and it is rapidly cleared from serum at a site distant from the lung, probably the liver. Secretion of ACE into the vascular compartment by the lung is impaired in the period immediately after cardiopulmonary bypass.