Epidemiology, Mechanical Power, and 3-Year Outcomes in Acute Respiratory Distress Syndrome Patients Using Standardized Screening. An Observational Cohort Study.

Rationale: Limited data on the epidemiology of acute respiratory distress syndrome (ARDS) using a standardized screening program exist.Objectives: To describe the population-based incidence of hypoxemic respiratory failure and ARDS using a prospective standardized screening protocol; and to describe the mechanical ventilation practice and the mechanical power and examine their association with 28-day and 3-year survival outcomes.Methods: A prospective standardized screening program for ARDS, as a quality improvement initiative, was initiated at four adult intensive care units over a 27-month period. An ancillary analysis of this observational cohort was performed. Patients requiring mechanical ventilation for ≥24 hours underwent prospective and consecutive screening using standardized ventilator settings. Patient physiological data and outcomes were collected prospectively through an electronic clinical-information system and retrospectively analyzed to apply Berlin criteria.Results: Screened were 7,944 patients, among which 986 (12.4%) had hypoxemic respiratory failure (arterial oxygen tension to inspired fraction of oxygen ratio ≤300), and 731 (9.2%) met criteria for ARDS. Age-adjusted incidence of hypoxemic respiratory failure and ARDS were 37.7 and 27.6 cases per 100,000 person-years, respectively. Patients sustaining the diagnosis of ARDS had a hospital mortality of 26.5% for mild, 31.8% for moderate, and 60.0% for severe ARDS and a 3-year mortality of 43.5% for mild, 46.9% for moderate, and 71.1% for severe ARDS. Mechanical power >22 J/min was associated with increased 28-day hospital and 3-year mortality. Determinants of mechanical power associated with lower 28-day hospital and 3-year survival included plateau pressure >30 cm H2O and driving pressure >15 cm H2O, but not tidal volumes >8 ml/kg of predicted body weight.Conclusions: Using standardized screening, a large proportion of patients with hypoxemic respiratory failure met criteria for ARDS. Increasing ARDS severity was associated with increased 28-day hospital and 3-year mortality. Increased mechanical power was associated with increased mortality. Potentially modifiable determinants of mechanical power associated with lower survival included plateau pressure and driving pressure.

Early life adversity potentiates expression of addiction-related traits.

Many individuals sporadically and circumstantially sample addictive drugs, yet few become addicted. The individual vulnerabilities underlying the development of addiction are not well understood. Correlational findings show that early life adversity is associated with a greater propensity to develop drug addiction. However, the mechanisms by which early life adversity increases addiction vulnerability are unknown. Separate lines of research have found that several traits are associated with addiction. Here, we examined the effects of early life adversity on addiction-related traits in adulthood. We weaned male and female Sprague-Dawley rats (postnatal day - PND21) and randomly assigned them to either a non-adversity group (N-ADV) or an adversity group (ADV). ADV rats experienced adversity from PND 21-35, they were: a) singly housed, b) food restricted for 12h/day, c) subjected to forced-swim sessions, and d) restrained and exposed to predator odour (1h). As adults, rats were tested for impulsivity, anxiety-like behaviour, novelty preference, and attribution of incentive salience to a reward cue. ADV rats showed enhanced novelty preference and attributed greater incentive value to a reward cue. Compared to N-ADV rats, a greater proportion of ADV rats expressed multiple addiction risk traits. Furthermore, fewer ADV rats expressed no addiction risk traits. This effect was most evident in female ADV rats.