Performance of acute respiratory distress syndrome definitions in a high acuity paediatric intensive care unit

Background For years, paediatric critical care practitioners used the adult American European Consensus Conference (AECC) and revised Berlin Definition (BD) for acute respiratory distress syndrome (ARDS) to study the epidemiology of paediatric ARDS (PARDS). In 2015, the paediatric specific definition, Paediatric Acute Lung Injury Consensus Conference (PALICC) was developed. The use of non-invasive metrics of oxygenation to stratify disease severity were introduced in this definition, although this potentially may lead to a confounding effect of disease severity since it is more common to place indwelling arterial lines in sicker patients. We tested the hypothesis that PALICC outperforms AECC/BD in our high acuity PICU, which employs a liberal use of indwelling arterial lines and high-frequency oscillatory ventilation (HFOV). Methods We retrospectively collected data from children < 18 years mechanically ventilated for at least 24 h in our tertiary care, university-affiliated paediatric intensive care unit. The primary endpoint was the difference in the number of PARDS cases between AECC/BD and PALICC. Secondary endpoints included mortality and ventilator free days. Performance was assessed by the area under the receiver operating characteristics curve (AUC-ROC). Results Data from 909 out of 2433 patients was eligible for analysis. AECC/BD identified 35 (1.4%) patients (mortality 25.7%), whereas PALICC identified 135 (5.5%) patients (mortality 14.1%). All but two patients meeting AECC/Berlin criteria were also identified by PALICC. Almost half of the cohort (45.2%) had mild, 33.3% moderate and 21.5% severe PALICC PARDS at onset. Highest mortality rates were seen in patients with AECC acute lung injury (ALI)/mild Berlin and severe PALICC PARDS. The AUC-ROC for Berlin was the highest 24 h (0.392 [0.124–0.659]) after onset. PALICC showed the highest AUC-ROC at the same moment however higher than Berlin (0.531 [0.345–0.716]). Mortality rates were significantly increased in patients with bilateral consolidations (9.3% unilateral vs 26.3% bilateral, p = 0.025). Conclusions PALICC identified more new cases PARDS than the AECC/Berlin definition. However, both PALICC and Berlin performed poorly in terms of mortality risk stratification. The presence of bilateral consolidations was associated with a higher mortality rate. Our findings may be considered in future modifications of the PALICC criteria.

COVID-19: Up to 82% critically ill patients had low Vitamin C values

There are limited proven therapeutic options for the prevention and treatment of COVID-19. We underwent an observational study with the aim of measure plasma vitamin C levels in a population of critically ill COVID-19 adult patients who met ARDS criteria according to the Berlin definition. This epidemiological study brings to light that up to 82% had low Vitamin C values. Notwithstanding the limitation that this is a single-center study, it nevertheless shows an important issue. Given the potential role of vitamin C in sepsis and ARDS, there is gathering interest of whether supplementation could be beneficial in COVID-19.

Accuracy of the Radiographic Assessment of Lung Edema Score for the Diagnosis of ARDS

Background: Bilateral opacities on chest radiographs are part of the Berlin Definition for Acute Respiratory Distress Syndrome (ARDS) but have poor interobserver reliability. The “Radiographic Assessment of Lung Edema” (RALE) score was recently proposed for evaluation of the extent and density of alveolar opacities on chest radiographs of ARDS patients. The current study determined the accuracy of the RALE score for the diagnosis and the prognosis of ARDS.Methods:Post-hoc analysis of a cohort of invasively ventilated intensive care unit (ICU) patients expected to need invasive ventilation for &gt;24 h. The Berlin Definition was used as the gold standard. The RALE score was calculated for the first available chest radiograph after start of ventilation in the ICU. The primary endpoint was the diagnostic accuracy for ARDS of the RALE score. Secondary endpoints included the prognostic value of the RALE score for ICU and hospital mortality, and the association with ARDS severity, and the PaO2/FiO2. Receiver operating characteristic (ROC) curves were constructed, and the optimal cutoff was used to determine sensitivity, specificity and the negative and positive predictive value of the RALE score for ARDS.Results: The study included 131 patients, of whom 30 had ARDS (11 mild, 15 moderate, and 4 severe ARDS). The first available chest radiograph was obtained median 0 [0 to 1] days after start of invasive ventilation in ICU. Compared to patients without ARDS, a higher RALE score was found in patients with ARDS (24 [interquartile range (IQR) 16–30] vs. 6 [IQR 3–11]; P &lt; 0.001), with RALE scores of 20 [IQR 14–24], 26 [IQR 16–32], and 32 [IQR 19–36] for mild, moderate and severe ARDS, respectively, (P = 0.166). The area under the ROC for ARDS was excellent (0.91 [0.86–0.96]). The best cutoff for ARDS diagnosis was 10 with 100% sensitivity, 71% specificity, 51% positive predictive value and 100% negative predictive value. The RALE score was not associated with ICU or hospital mortality, and weakly correlated with the PaO2/FiO2.Conclusion: In this cohort of invasively ventilated ICU patients, the RALE score had excellent diagnostic accuracy for ARDS.

Derivation and Validation of an Automated Search Strategy to Retrospectively Identify Acute Respiratory Distress Patients Per Berlin Definition

Purpose: Acute respiratory distress syndrome (ARDS) is common in critically ill patients and linked with serious consequences. A manual chart review for ARDS diagnosis could be laborious and time-consuming. We developed an automated search strategy to retrospectively identify ARDS patients using the Berlin definition to allow for timely and accurate ARDS detection.Methods: The automated search strategy was created through sequential steps, with keywords applied to an institutional electronic medical records (EMRs) database. We included all adult patients admitted to the intensive care unit (ICU) at the Mayo Clinic (Rochester, MN) from January 1, 2009 to December 31, 2017. We selected 100 patients at random to be divided into two derivation cohorts and identified 50 patients at random for the validation cohort. The sensitivity and specificity of the automated search strategy were compared with a manual medical record review (gold standard) for data extraction of ARDS patients per Berlin definition.Results: On the first derivation cohort, the automated search strategy achieved a sensitivity of 91.3%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 93.1%. On the second derivation cohort, it reached the sensitivity of 90.9%, specificity of 100%, PPV of 100%, and NPV of 93.3%. The strategy performance in the validation cohort had a sensitivity of 94.4%, specificity of 96.9%, PPV of 94.4%, and NPV of 96.9%.Conclusions: This automated search strategy for ARDS with the Berlin definition is reliable and accurate, and can serve as an efficient alternative to time-consuming manual data review.

Association Between Obesity and Short-And Long-Term Mortality in Patients With Acute Respiratory Distress Syndrome Based on the Berlin Definition

PurposeAcute respiratory distress syndrome (ARDS) is one of the most common causes of death in intensive care units (ICU). Previous studies have reported the potential protective effect of obesity on ARDS patients. However, these findings are inconsistent, in which less was reported on long-term prognosis and diagnosed ARDS by Berlin definition. This study aimed to investigate the relationship between obesity and short-term and long-term mortality in patients with ARDS based on the Berlin Definition.MethodsThis is a retrospective cohort study from the Medical Information Mart for Intensive Care III (MIMIC-III) database, in which all the patients were diagnosed with ARDS according to the Berlin definition. The patients were divided into four groups according to the WHO body mass index (BMI) categories. The multivariable logistic regression and Cox regression analysis were used to investigate the relationship between BMI and short-term and long-term mortality.ResultA total of 2,378 patients with ARDS were enrolled in our study. In-hospital mortality was 27.92%, and 1,036 (43.57%) patients had died after 1-year follow-up. After adjusting for confounders, the in-hospital and 1-year mortality risks of obese patients were significantly lower than those of normal weight (OR 0.72, 95%CI 0.55–0.94, P=0.0168; HR 0.80, 95%CI 0.68–0.94 P=0.0084; respectively), while those mortality risks of underweight patients were higher than normal weight patients (P=0.0102, P=0.0184; respectively). The smooth curve showed that BMI, which was used as a continuous variable, was negatively correlated with in-hospital and 1-year mortality. The results were consistent after being stratified by age, gender, race, type of admission, severity of organ dysfunction, and severity of ARDS. The Kaplan-Meier survival curves showed that obese patients had significant lower 1-year mortality than normal weight patients.ConclusionWe found that obesity was associated with decreased risk of short-term and long-term mortality in patients with ARDS.

Acute respiratory distress syndrome (ARDS)

The incidence of describing acute respiratory distress syndrome (ARDS) is approximately 23% in mechanically ventilated patients. The diagnosis of ARDS varies widely; studies report a variation in the population diagnosed with ARDS, from 10 to 86 cases per 100,000. Complications of mechanical ventilation are common and include ventilator-associated pneumonia (VAP), barotrauma from excessive airway pressures, and volutrauma from excessive tidal volumes which may both worsen ARDS. Pneumothorax occurs in some patients, necessitating the placement of chest drains. This chapter starts with describing ARDS and the Berlin Definition, and its incidence. It also covers aetiology and physiology, then goes on to its treatment and general management. This includes respiratory support, position changes, and other treatments. Situation-dependent prognoses are outlined. Specific nursing care is also described.