Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a heterogeneous lung disease that is triggered by pulmonary and non-pulmonary pathol-ogies. It predominantly causes hypoxaemic respiratory failure and can lead to significant morbidity and mortality. Although ARDS re-mains underdiagnosed, 24% of mechanically ventilated patients in intensive care units and 33% of coronavirus disease (COVID-19) pa-tients admitted to the hospital are reported to have ARDS. Despite recent advances in treatment, mortality remains at more than 30% for all ARDS patients and 43% for severe ARDS. The pathophysiology is complex and involves acute pulmonary and systemic inflammation, alveolar oedema, and de-recruitment which lead to ventilation-perfusion mismatch, reduced lung compliance and hypoxaemia. Similarities in the pathophysiology of COVID-19 ARDS outnumber differences from non-COVID-19 ARDS. Inhomoge-neous distribution of transpulmonary pressure variation throughout the lungs in ARDS increases the risk of patient self-inflicted lung injury and ventilator-associated lung injury. Stratifying ARDS patients as per Berlin definition can help to recog-nize ARDS early, identify resource requirements and plan appropriate management. Treating the underlying cause, lung-protective ventila-tion and supportive care are the mainstays of clinical management. Multiple rescue therapies, novel treatments, and methods of facili-tating individualized ventilation have been described but many require further validation;and appropriate patient selection is warranted.

Intensive care admissions following rapid response team reviews in patients with COVID-19 in Australia

Objectives: To evaluate the epidemiology of rapid response team (RRT) reviews that led to intensive care unit (ICU) admissions, and to evaluate the frequency of in-hospital cardiac arrests (IHCAs) among ICU patients with confirmed coronavirus disease 2019 (COVID-19) in Australia. Design: Multicentre, retrospective cohort study. Setting: 48 public and private ICUs in Australia. Participants: All adults (aged ≥ 16 years) with confirmed COVID-19 admitted to participating ICUs between 25 January and 31 October 2020, as part of SPRINT-SARI (Short PeRiod IncideNce sTudy of Severe Acute Respiratory Infection) Australia, which were linked with ICUs contributing to the Australian and New Zealand Intensive Care Society Adult Patient Database (ANZICS APD). Main outcome measures and results: Of the 413 critically ill patients with COVID-19 who were analysed, 48.2% (199/413) were admitted from the ward and 30.5% (126/413) were admitted to the ICU following an RRT review. Patients admitted following an RRT review had higher Acute Physiology and Chronic Health Evaluation (APACHE) scores, fewer days from symptom onset to hospitalisation (median, 5.4 [interquartile range (IQR), 3.2–7.6] v 7.1 days [IQR, 4.1–9.8];P < 0.001) and longer hospitalisations (median, 18 [IQR, 11–33] v 13 days [IQR, 7–24];P < 0.001) compared with those not admitted via an RRT review. Admissions following RRT review comprised 60.3% (120/199) of all ward-based admissions. Overall, IHCA occurred in 1.9% (8/413) of ICU patients with COVID-19, and most IHCAs (6/8, 75%) occurred during ICU admission. There were no differences in IHCA rates or in ICU or hospital mortality rates based on whether a patient had a prior RRT review or not. Conclusions: This study found that RRT reviews were a common way for deteriorating ward patients with COVID-19 to be admitted to the ICU, and that IHCA was rare among ICU patients with COVID-19. © 2022, College of Intensive Care Medicine. All rights reserved.

Assessment of a novel marker of ICU strain, the ICU Activity Index, during the COVID-19 pandemic in Victoria, Australia

Objectives: To validate a real-time Intensive Care Unit (ICU) Activity Index as a marker of ICU strain from daily data available from the Critical Health Resource Information System (CHRIS), and to investigate the association between this Index and the need to transfer critically ill patients during the coronavirus disease 2019 (COVID-19) pandemic in Victoria, Australia. Design: Retrospective observational cohort study. Setting: All 45 hospitals with an ICU in Victoria, Australia. Participants: Patients in all Victorian ICUs and all critically ill patients transferred between Victorian hospitals from 27 June to 6 September 2020. Main outcome measure: Acute interhospital transfer of one or more critically ill patients per day from one site to an ICU in another hospital. Results: 150 patients were transported over 61 days from 29 hospitals (64%). ICU Activity Index scores were higher on days when critical care transfers occurred (median, 1.0 [IQR, 0.4-1.7] v 0.6 [IQR, 0.3-1.2];P < 0.001). Transfers were more common on days of higher ICU occupancy, higher numbers of ventilated or COVID-19 patients, and when more critical care staff were unavailable. The highest ICU Activity Index scores were observed at hospitals in northwestern Melbourne, where the COVID-19 disease burden was greatest. After adjusting for confounding factors, including occupancy and lack of available ICU staff, a rising ICU Activity Index score was associated with an increased risk of a critical care transfer (odds ratio, 4.10;95% CI, 2.34-7.18;P < 0.001). Conclusions: The ICU Activity Index appeared to be a valid marker of ICU strain during the COVID-19 pandemic. It may be useful as a real-time clinical indicator of ICU activity and predict the need for redistribution of critical ill patients.