ABSTRACT
INTRODUCTION: Awake prone positioning (APP) has been widely applied in non-intubated patients with COVID-19-related acute hypoxemic respiratory failure. However, the results from randomised controlled trials (RCTs) are inconsistent. We performed a meta-analysis to assess the efficacy and safety of APP and to identify the subpopulations that may benefit the most from it. METHODS: We searched five electronic databases from inception to August 2022 (PROSPERO registration: CRD42022342426). We included only RCTs comparing APP with supine positioning or standard of care with no prone positioning. Our primary outcomes were the risk of intubation and all-cause mortality. Secondary outcomes included the need for escalating respiratory support, length of ICU and hospital stay, ventilation-free days, and adverse events. RESULTS: We included 11 RCTs and showed that APP reduced the risk of requiring intubation in the overall population (RR 0.84, 95% CI: 0.74-0.95; moderate certainty). Following the subgroup analyses, a greater benefit was observed in two patient cohorts: those receiving a higher level of respiratory support (compared with those receiving conventional oxygen therapy) and those in intensive care unit (ICU) settings (compared to patients in non-ICU settings). APP did not decrease the risk of mortality (RR 0.93, 95% CI: 0.77-1.11; moderate certainty) and did not increase the risk of adverse events. CONCLUSIONS: In patients with COVID-19-related acute hypoxemic respiratory failure, APP likely reduced the risk of requiring intubation, but failed to demonstrate a reduction in overall mortality risk. The benefits of APP are most noticeable in those requiring a higher level of respiratory support in an ICU environment.
ABSTRACT
In critically ill patients with COVID-19, concomitant abnormalities of coagulation have been seen with an unusually high incidence, often despite seemingly appropriate prophylactic anti-coagulation. It appears that standard coagulation tests are limited in their ability to accurately reflect the severity of the prothrombotic phenotype observed in severe COVID-19 infections. In this narrative review we consider the role of a global haemostatic assay, rotational thromboelastometry (ROTEM), as a near bedside test allowing a more comprehensive assessment of haemostatic function in the context of COVID-19 infection. A comprehensive literature search was conducted on PubMed using the keywords "COVID-19" OR "SARS-CoV-2" AND "Rotational thromboelastometry". Sixteen original articles were included for analysis and two existing literature reviews were considered. Whilst not the perfect substitute for in vivo coagulation, studies utilising rotational thromboelastometry assays in COVID-19 patients have demonstrated increased maximum clot firmness (consistent with hypercoagulability) and reduced maximum lysis (consistent with "fibrinolytic shutdown"). There is a possible association with disease severity and degree of hypercoagulability and hypofibrinolysis as a possible tool for risk stratification and the potential modulation of fibrinogen-dependent maximum clot firmness with enhanced anticoagulation strategies. Precisely how these coagulation abnormalities can be modified by optimum, individualised medical interventions to improve clinical outcomes, however, remains unclear.