Acute Respiratory Distress Syndrome

Author(s):  
Richard K. Patch ◽  
James Y. Findlay

Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by acute hypoxemic respiratory failure. Patients with ARDS have pulmonary damage from an acute, usually severe, diffuse inflammatory lung injury that leads to increased vascular permeability and loss of aerated tissue. Mortality from ARDS is estimated to range from 26% to 58%, and in-hospital mortality is high (46.1%) for those with severe ARDS. Survivors have extensive morbidity, including neurocognitive dysfunction, physical disabilities, and psychiatric illnesses such as depression, anxiety, and posttraumatic stress disorder. Lung function may be compromised for as long as 5 years.

1998 ◽  
Vol 7 (5) ◽  
pp. 335-345 ◽  
Author(s):  
MA Curley ◽  
JC Fackler

OBJECTIVE: The purpose of the study was to describe the patterns of weaning from mechanical ventilation in young children recovering from acute hypoxemic respiratory failure. METHODS: Decision-making rules on progressive weaning were developed and applied to existing data on 82 patients 2 weeks to 6 years old in the Pediatric Acute Respiratory Distress Syndrome Data Set. RESULTS: Three patterns of weaning progress were detected: sprint, consistent, and inconsistent. Length of ventilation and weaning progressively increased from the sprint, to the consistent, to the inconsistent subset. Patients in the inconsistent subset were most likely to have a systemic (sepsis or shock) trigger of acute respiratory distress syndrome and to be rated as having at least moderate disability at discharge. Hypothesis-generating univariate and then multivariate logistic regression analyses indicated that patients who experienced more days of mechanical ventilation before the start of weaning and who had a higher oxygenation index during the weaning process were most likely to have an inconsistent pattern of weaning. CONCLUSION: Patterns of weaning are discernible in a population of young children and indicate a subset at risk for inconsistent weaning. Knowing the patterns of weaning may help clinicians anticipate, perhaps plot, and then modulate a patient's weaning trajectory.


2020 ◽  
Author(s):  
Neha Alhad Sathe ◽  
Leila R. Zelnick ◽  
Carmen Mikacenic ◽  
Eric D. Morrell ◽  
Pavan K. Bhatraju ◽  
...  

Abstract Background Identifying effective therapies in heterogeneous conditions like acute hypoxemic respiratory failure (AHRF) depends on defining sub-phenotypes with distinct prognosis or therapeutic response. Prior efforts have focused on acute respiratory distress syndrome (ARDS), although ARDS is a minority of all AHRF patients, has limited reliability in research, and is similarly heterogeneous. We propose a novel AHRF sub-phenotype called persistent hypoxemic respiratory failure (PHRF), defined by PaO2:FiO2 ratio ≤ 300 in individuals still requiring mechanical ventilation on day 3 following intubation. We hypothesized individuals with PHRF (+ PHRF) have greater mortality than individuals without PHRF (-PHRF), irrespective of ARDS (+/-ARDS). Methods We included mechanically ventilated AHRF patients (n = 768) from a single-center prospective cohort of medical and surgical ICU patients. We estimated the relative risk of 28-day inpatient mortality associated with + PHRF compared to -PHRF using generalized linear models. We also compared mortality and baseline log-transformed plasma biomarkers of inflammation and endothelial activation/dysfunction in + PHRF/-ARDS, -PHRF/+ARDS, and + PHRF/+ARDS compared to -PHRF/-ARDS. Results Cumulative incidence of + PHRF was 53% (n = 408), of whom 51% were + ARDS by ICU day 3 (n = 209). +PHRF was associated with a 1.55-fold higher risk of death (95% CI: 1.02, 2.34) compared to -PHRF, adjusting for demographics, chronic respiratory disease, and APACHE-III. Absolute mortality was higher in + PHRF/+ARDS (23%) and + PHRF/+ARDS (15%) patients than -PHRF/+ARDS (12%) and -PHRF/-ARDS (7%) patients. Interleukin-6 was 2.36-fold (95% CI: 1.47, 3.80) and 2.62-fold (1.63, 4.20) higher in + PHRF/-ARDS and + PHRF/+ARDS compared to -PHRF/-ARDS; granulocyte-colony stimulating factor was 1.96-fold (95% CI: 1.28, 3.01) and 1.82-fold (95% CI: 1.16, 2.85) higher; angiopoeitin-2 was 1.32-fold (95% CI: 1.01, 1.73) and 1.59-fold (95% CI: 1.21, 2.09) higher. In contrast, -PHRF/+ARDS patients did not have significantly different mortality or plasma biomarkers from -PHRF/-ARDS patients in adjusted models. Conclusions PHRF represents a common sub-phenotype of patients with AHRF, characterized by higher mortality and higher biomarkers of inflammation and endothelial dysfunction than -PHRF. PHRF captures many high-risk patients not included in current ARDS definition who may share biologic features with ARDS. Identifying patients with PHRF can support clinical prognostication and targeted trial enrollment for investigational therapies in the broad AHRF population.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jesús Villar ◽  
Carlos Ferrando ◽  
Gerardo Tusman ◽  
Lorenzo Berra ◽  
Pedro Rodríguez-Suárez ◽  
...  

The acute respiratory distress syndrome (ARDS) is a severe form of acute hypoxemic respiratory failure caused by an insult to the alveolar-capillary membrane, resulting in a marked reduction of aerated alveoli, increased vascular permeability and subsequent interstitial and alveolar pulmonary edema, reduced lung compliance, increase of physiological dead space, and hypoxemia. Most ARDS patients improve their systemic oxygenation, as assessed by the ratio between arterial partial pressure of oxygen and inspired oxygen fraction, with conventional intensive care and the application of moderate-to-high levels of positive end-expiratory pressure. However, in some patients hypoxemia persisted because the lungs are markedly injured, remaining unresponsive to increasing the inspiratory fraction of oxygen and positive end-expiratory pressure. For decades, mechanical ventilation was the only standard support technique to provide acceptable oxygenation and carbon dioxide removal. Mechanical ventilation provides time for the specific therapy to reverse the disease-causing lung injury and for the recovery of the respiratory function. The adverse effects of mechanical ventilation are direct consequences of the changes in pulmonary airway pressures and intrathoracic volume changes induced by the repetitive mechanical cycles in a diseased lung. In this article, we review 14 major successful and unsuccessful randomized controlled trials conducted in patients with ARDS on a series of techniques to improve oxygenation and ventilation published since 2010. Those trials tested the effects of adjunctive therapies (neuromuscular blocking agents, prone positioning), methods for selecting the optimum positive end-expiratory pressure (after recruitment maneuvers, or guided by esophageal pressure), high-frequency oscillatory ventilation, extracorporeal oxygenation, and pharmacologic immune modulators of the pulmonary and systemic inflammatory responses in patients affected by ARDS. We will briefly comment physiology-based gaps of negative trials and highlight the possible needs to address in future clinical trials in ARDS.


2021 ◽  
pp. 088506662110190
Author(s):  
Saminder Singh Kalra ◽  
Johnny Jaber ◽  
Bashar N. Alzghoul ◽  
Ryan Hyde ◽  
Sarina Parikh ◽  
...  

Background: Patients with acute respiratory distress syndrome (ARDS) are highly susceptible to developing delirium for a multitude of reasons. Previous studies have linked pre-existing depression with an increased risk of postoperative delirium in patients undergoing cardiac and non-cardiac surgery. However, the evidence regarding the association between pre-existing psychiatric illnesses and delirium in ARDS patients is unknown. In this study, we aim to determine the relationship between pre-existing psychiatric illness and the risk of development of delirium amongst ARDS patients. Study Design and Methods: We performed a retrospective study of a mixed group of patients admitted to the intensive care unit (ICU) between January 2016 and December 2019 with a diagnosis of ARDS per the Berlin definition. The study group was divided into 2 cohorts: subjects with delirium and subjects without delirium. Comparison between the 2 groups was conducted to examine the impact of pre-existing psychiatric illnesses including major depressive disorder (MDD), generalized anxiety disorder (GAD), bipolar disorder, schizophrenia, or post-traumatic stress disorder. Multivariable logistic regression analysis was performed adjusting for benzodiazepine use, sedatives, analgesics, sequential organ failure assessment score, and corticosteroid use to determine the association between pre-existing psychiatric disorders and delirium. Results: 286 patients with ARDS were identified; 124 (43%) of whom were diagnosed with ICU delirium. In patients diagnosed with ICU delirium, 49.2% were found to have preexisting psychiatric illnesses, compared to 34.0% without any preexisting psychiatric illness (OR = 1.94, P = 0.01). In a subgroup analysis of individual psychiatric illnesses, GAD and MDD were associated with the development of delirium (OR = 1.88, P = 0.04 and OR = 1.76, P = 0.05 respectively). Interpretation: ARDS patients with preexisting psychiatric illnesses, particularly GAD and MDD are associated with an increased risk of developing ICU delirium. Clinicians should be aware of the effect of psychiatric co-morbidities on developing delirium in critically ill patients.


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