ICU Respiratory Distress Often Goes Unrecognized

Michael’s Hospital (Toronto, Canada), the University of Milan-Bicocca (Monza, Italy), and other institutions reported results of an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation. The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was conducted during four consecutive weeks in the winter of 2014 in a convenience sample of 459 ICU’s from 50 countries across five continents.

The object of the study was to evaluate ICU incidence and outcome of ARDS, and to assess clinician recognition, ventilation management, and use of adjuncts, such as prone positioning, in routine clinical practice for patients fulfilling the ARDS Berlin definition. The main outcome of the study was ICU incidence of ARDS, with secondary outcomes including assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS.

The results revealed that 3,022 (10.4%) of the 29,144 patients admitted to the ICU over the course of the study were found to have ARDS, but only about 60% of the cases were identified during the ICU stay. Clinical ARDS recognition ranged from 51.3% in mild cases to 78.5% in severe cases, and was associated with higher positive end-expiratory pressure (PEEP), greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% among mild ARDS and 40.3% and 46.1% among patients with moderate and severe ARDS, respectively. The study was presented at the Society for Critical Care Medicine Critical Care Congress, held during February 2016 in Orlando (FL, USA).

“ARDS is an acute, inflammatory lung condition characterized by increased pulmonary vascular permeability, increased lung weight, and loss of aerated lung tissue,” said study author John Laffey, MD, of St. Michaels Hospital. “We don't have major therapies that can arrest the course of this disease, but we do know that the way we support ventilation and gas exchange can have an impact. And other supportive care, such as prone positioning and giving muscle relaxers, may also help.”

ARDS is a disease of the alveoli of the lungs that leads to decreased exchange of oxygen and carbon dioxide (CO2). It is associated with several pathologic changes: the release of inflammatory chemicals, breakdown of the cells lining the lung's blood vessels, surfactant loss leading to increased surface tension in the lung, fluid accumulation in the lung, and excessive fibrous connective tissue formation. The condition affects an estimated 2.2 million people worldwide each year, and has a high mortality rate of 20%–50%.

Related Links:
St. Michael’s Hospital
University of Milan-Bicocca