Tài Pham

Epidemiology, Patterns of Care, and Mortality for Patients With Acute Respiratory Distress Syndrome in Intensive Care Units in 50 Countries

IMPORTANCE Limited information exists about the epidemiology, recognition, management, and outcomes of patients with the acute respiratory distress syndrome (ARDS). OBJECTIVES To evaluate intensive care unit (ICU) incidence and outcome of ARDS and to assess clinician recognition, ventilation management, and use of adjuncts-for example prone positioning-in routine clinical practice for patients fulfilling the ARDS Berlin Definition. DESIGN, SETTING, AND PARTICIPANTS The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents. EXPOSURES Acute respiratory distress syndrome. MAIN OUTCOMES AND MEASURES The primary outcome was ICU incidence of ARDS. Secondary outcomes included 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. RESULTS Of 29,144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0% (95% CI, 28.2%-31.9%); of moderate ARDS, 46.6% (95% CI, 44.5%-48.6%); and of severe ARDS, 23.4% (95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4% (95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5% (95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1% (95% CI, 38.2-42.1), whereas 82.6% (95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3% (95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% (95% CI, 31.4%-38.5%) for those with mild, 40.3% (95% CI, 37.4%-43.3%) for those with moderate, and 46.1% (95% CI, 41.9%-50.4%) for those with severe ARDS. CONCLUSIONS AND RELEVANCE Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02010073.

Extracorporeal membrane oxygenation for pandemic influenza A(H1N1)-induced acute respiratory distress syndrome: a cohort study and propensity-matched analysis.

RATIONALE Many patients with severe acute respiratory distress syndrome (ARDS) caused by influenza A(H1N1) infection receive extracorporeal membrane oxygenation (ECMO) as a rescue therapy. OBJECTIVES To analyze factors associated with death in ECMO-treated patients and the influence of ECMO on intensive care unit (ICU) mortality. METHODS Data from patients admitted for H1N1-associated ARDS to French ICUs were prospectively collected from 2009 to 2011 through the national REVA registry. We analyzed factors associated with in-ICU death in ECMO recipients, and the potential benefit of ECMO using a propensity score-matched (1:1) cohort analysis. MEASUREMENTS AND MAIN RESULTS A total of 123 patients received ECMO. By multivariate analysis, increasing values of age, lactate, and plateau pressure under ECMO were associated with death. Of 103 patients receiving ECMO during the first week of mechanical ventilation, 52 could be matched to non-ECMO patients of comparable severity, using a one-to-one matching and using control subjects only once. Mortality did not differ between the two matched cohorts (odds ratio, 1.48; 95% confidence interval, 0.68-3.23; P = 0.32). Interestingly, the 51 ECMO patients who could not be matched were younger, had lower Pa(o(2))/Fi(o(2)) ratio, had higher plateau pressure, but also had a lower ICU mortality rate than the 52 matched ECMO patients (22% vs. 50%; P < 0.01). CONCLUSIONS Under ECMO, an ultraprotective ventilation strategy minimizing plateau pressure may be required to improve outcome. When patients with severe influenza A(H1N1)-related ARDS treated with ECMO were compared with conventionally treated patients, no difference in mortality rates existed. The unmatched, severely hypoxemic, and younger ECMO-treated patients had, however, a lower mortality.

Heated and Humidified High-Flow Oxygen Therapy Reduces Discomfort During Hypoxemic Respiratory Failure

BACKGROUND: Non-intubated critically ill patients are often treated by high-flow oxygen for acute respiratory failure. There is no current recommendation for humidification of oxygen devices. METHODS: We conducted a prospective randomized trial with a final crossover period to compare nasal airway caliber and respiratory comfort in patients with acute hypoxemic respiratory failure receiving either standard oxygen therapy with no humidification or heated and humidified high-flow oxygen therapy (HHFO2) in a medical ICU. Nasal airway caliber was measured using acoustic rhinometry at baseline, after 4 and 24 hours (H4 and H24), and 4 hours after crossover (H28). Dryness of the nose, mouth, and throat was auto-evaluated and assessed blindly by an otorhinolaryngologist. After the crossover, the subjects were asked which system they preferred. RESULTS: Thirty subjects completed the protocol and were analyzed. Baseline median oxygen flow was 9 and 12 L/min in the standard and HHFO2 groups, respectively (P = .21). Acoustic rhinometry measurements showed no difference between the 2 systems. The dryness score was significantly lower in the HHFO2 group at H4 (2 vs 6, P = .007) and H24 (0 vs 8, P = .004). During the crossover period, dryness increased promptly after switching to standard oxygen and decreased after switching to HHFO2 (P = .008). Sixteen subjects (53%) preferred HHFO2 (P = .01), especially those who required the highest flow of oxygen at admission (P = .05). CONCLUSIONS: Upper airway caliber was not significantly modified by HHFO2, compared to standard oxygen therapy, but HHFO2 significantly reduced discomfort in critically ill patients with respiratory failure. The system is usually preferred over standard oxygen therapy.

Noninvasive Ventilation of Patients with Acute Respiratory Distress Syndrome. Insights from the LUNG SAFE Study

Rationale: Noninvasive ventilation (NIV) is increasingly used in patients with acute respiratory distress syndrome (ARDS). The evidence supporting NIV use in patients with ARDS remains relatively sparse. Objectives: To determine whether, during NIV, the categorization of ARDS severity based on the PaO2/FiO2 Berlin criteria is useful. Methods: The LUNG SAFE (Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure) study described the management of patients with ARDS. This substudy examines the current practice of NIV use in ARDS, the utility of the PaO2/FiO2 ratio in classifying patients receiving NIV, and the impact of NIV on outcome. Measurements and Main Results: Of 2,813 patients with ARDS, 436 (15.5%) were managed with NIV on Days 1 and 2 following fulfillment of diagnostic criteria. Classification of ARDS severity based on PaO2/FiO2 ratio was associated with an increase in intensity of ventilatory support, NIV failure, and intensive care unit (ICU) mortality. NIV failure occurred in 22.2% of mild, 42.3% of moderate, and 47.1% of patients with severe ARDS. Hospital mortality in patients with NIV success and failure was 16.1% and 45.4%, respectively. NIV use was independently associated with increased ICU (hazard ratio, 1.446 [95% confidence interval, 1.159‐1.805]), but not hospital, mortality. In a propensity matched analysis, ICU mortality was higher in NIV than invasively ventilated patients with a PaO2/FiO2 lower than 150 mm Hg. Conclusions: NIV was used in 15% of patients with ARDS, irrespective of severity category. NIV seems to be associated with higher ICU mortality in patients with a PaO2/FiO2 lower than 150 mm Hg. Clinical trial registered with www.clinicaltrials.gov (NCT 02010073).

Epidemiology of Weaning Outcome according to a New Definition. The WIND Study

Rationale: The weaning process concerns all patients receiving mechanical ventilation. A previous classification into simple, prolonged, and difficult weaning ignored weaning failure and presupposed the use of spontaneous breathing trials. Objectives: To describe the weaning process, defined as starting with any attempt at separation from mechanical ventilation and its prognosis, according to a new operational classification working for all patients under ventilation. Methods: This was a multinational prospective multicenter observational study over 3 months of all patients receiving mechanical ventilation in 36 intensive care units, with daily collection of ventilation and weaning modalities. Pragmatic definitions of separation attempt and weaning success allowed us to allocate patients in four groups. Measurements and Main Results: A total of 2,729 patients were enrolled. Although half of them could not be classified using the previous definition, 99% entered the groups on the basis of our new definition as follows: 24% never started a weaning process, 57% had a weaning process of less than 24 hours (group 1), 10% had a difficult weaning of more than 1 day and less than 1 week (group 2), and 9% had a prolonged weaning duration of 1 week or more (group 3). Duration of ventilation, intensive care unit stay, and mortality (6, 17, and 29% for the three groups, respectively) all significantly increased from one group to the next. The unadjusted risk of dying was 19% after the first separation attempt and increased to 37% after 10 days. Conclusions: A new classification allows us to categorize all weaning situations. Every additional day without a weaning success after the first separation attempt increases the risk of dying.

Fifty Years of Research in ARDS.The Epidemiology of Acute Respiratory Distress Syndrome. A 50th Birthday Review

&NA; Since its first description 50 years ago, no other intensive care syndrome has been as extensively studied as acute respiratory distress syndrome (ARDS). Despite this extensive body of research, many basic epidemiologic questions remain unsolved. The lack of gold standard tests jeopardizes accurate diagnosis and translational research. Wide variation in the population incidence has been reported, making even simple estimates of the burden of disease problematic. Despite these limitations, there has been an increase in the understanding of pathophysiology and important risk factors both for the development of ARDS and for important patient‐centered outcomes like mortality. In this Critical Care Perspective, we discuss the historical context of ARDS description and attempts at its definition. We highlight the epidemiologic challenges of studying ARDS, as well as other intensive care syndromes, and propose solutions to address them. We update the current knowledge of ARDS trends in incidence and mortality, risk factors, and recently described endotypes.

Interest of a simple on-line screening registry for measuring ICU burden related to an influenza pandemic

IntroductionThe specific burden imposed on Intensive Care Units (ICUs) during the A/H1N1 influenza 2009 pandemic has been poorly explored. An on-line screening registry allowed a daily report of ICU beds occupancy rate by flu infected patients (Flu-OR) admitted in French ICUs.MethodsWe conducted a prospective inception cohort study with results of an on-line screening registry designed for daily assessment of ICU burden.ResultsAmong the 108 centers participating to the French H1N1 research network on mechanical ventilation (REVA) - French Society of Intensive Care (SRLF) registry, 69 ICUs belonging to seven large geographical areas voluntarily participated in a website screening-registry. The aim was to daily assess the ICU beds occupancy rate by influenza-infected and non-infected patients for at least three weeks. Three hundred ninety-one critically ill infected patients were enrolled in the cohort, representing a subset of 35% of the whole French 2009 pandemic cohort; 73% were mechanically ventilated, 13% required extra corporal membrane oxygenation (ECMO) and 22% died. The global Flu-OR in these ICUs was only 7.6%, but it exceeded a predefined 15% critical threshold in 32 ICUs for a total of 103 weeks. Flu-ORs were significantly higher in University than in non-University hospitals. The peak ICU burden was poorly predicted by observations obtained at the level of large geographical areas.ConclusionsThe peak Flu-OR during the pandemic significantly exceeded a 15% critical threshold in almost half of the ICUs, with an uneven distribution with time, geographical areas and between University and non-University hospitals. An on-line assessment of Flu-OR via a simple dedicated registry may contribute to better match resources and needs.

Prevalence and Impact on Weaning of Pleural Effusion at the Time of Liberation from Mechanical Ventilation: A Multicenter Prospective Observational Study

Background: Pleural effusion is frequent in intensive care unit patients, but its impact on the outcome of weaning remains unknown. Methods: In a prospective study performed in three intensive care units, pleural ultrasound was performed at the first spontaneous breathing trial to detect and quantify pleural effusion (small, moderate, and large). Weaning failure was defined by a failed spontaneous breathing trial and/or extubation requiring any form of ventilatory support within 48 h. The primary endpoint was the prevalence of pleural effusion according to weaning outcome. Results: Pleural effusion was detected in 51 of 136 (37%) patients and was quantified as moderate to large in 18 (13%) patients. As compared to patients with no or small pleural effusion, their counterparts were more likely to have chronic renal failure (39 vs. 7%; P = 0.01), shock as the primary reason for admission (44 vs. 19%; P = 0.02), and a greater weight gain (+4 [0 to 7] kg vs. 0 [−1 to 5] kg; P = 0.02). The prevalence of pleural effusion was similar in weaning success and weaning failure patients (odds ratio, 1.23; 95% CI, 0.61 to 2.49; P = 0.56), as was the prevalence of moderate to large pleural effusion (odds ratio, 0.89; 95% CI, 0.33 to 2.41; P = 1.00). Duration of mechanical ventilation and intensive care unit length of stay were similar between patients with no or small pleural effusion and those with moderate to large pleural effusion. Conclusions: Significant pleural effusion was observed in 13% of patients at the time of liberation from mechanical ventilation and was not associated with an alteration of weaning outcome. (ANESTHESIOLOGY 2017; 126:1107–15)

Does my patient really have ARDS

How often does ARDS go unrecognized in our ICUs? A recent international observation study launched by the working group of the European Society of Intensive Care Medicine after the release of the new Berlin definition of ARDS has brought many important results [1]. One of the most surprising—and challenging—findings was the large amount of under-recognition by clinicians. Indeed, this study included all hypoxemic patients (PaO2/FiO2 ratio below 300 mmHg) under mechanical ventilation and the diagnosis was made automatically when criteria for the definition were fulfilled [2]. Both on admission and at discharge, the question was specifically asked whether the patient, at any time during the ICU stay, was qualified as having ARDS. Clinician recognition of ARDS ranged from only 51.3 % (95 % CI, 47.5–55.0 %) for mild ARDS to 78.5 % (95 % CI, 74.8–81.8 %) for severe ARDS. This had clear consequences since ventilatory settings were different in those with “unrecognized” ARDS. Not surprisingly, the patients with recognized ARDS were sicker in all categories. Interestingly also, the number of patients per physician or nurse in a given ICU negatively influenced this recognition. Therefore it seems important to understand why this syndrome is so often unrecognized (Fig. 1).

Incidence of Acute Respiratory Distress Syndrome—Reply

remains unresolved.2,3 For example, among dual users of VA and Medicare services, Medicare data alone captures 80% of a veteran’s total illness burden, whereas VA data only captures 33%.2 The VA does not have the same financial incentives to code that exist in non-VA health systems; thus, the true burden of disease among veterans is not fully captured by examining administrative claims alone. It is incumbent upon the VA to ensure that clinicians accurately code to reflect their patients’ true burden of disease, thus ensuring that future riskadjusted comparisons between VA and non-VA care reflect the true quality of care available within the VA.