Delayed mechanical ventilation with prolonged high-flow nasal cannula exposure time as a risk factor for mortality in acute respiratory distress syndrome due to SARS-CoV-2

High-Flow Nasal Cannula Application After Extubation in Acute Respiratory Failure Patients

Background: The optimal timing of high-flow nasal cannula (HFNC) application in acute respiratory failure patients remains uncertain. This study aimed to investigate the impact of HFNC on the outcomes of patients with acute respiratory failure, focusing on its use after extubation. Methods: This multicenter retrospective study enrolled adult acute respiratory failure patients requiring invasive mechanical ventilation during the first major outbreak of the COVID-19 pandemic in Taiwan from April to July 2021. Endpoints included prognosis after extubation as 28-day post-extubation mortality. Results: Among the patients, 107 received HFNC before intubation and 461 received conventional oxygen therapy (COT). Pre-intubation HFNC failure did not significantly affect hospital mortality but was associated with prolonged durations of mechanical ventilation and intensive care unit stay. Among 375 patients who underwent planned extubation, 158 received post-extubation HFNC and 217 received COT. HFNC application after extubation was associated with significantly reduced post-extubation 28-day mortality compared with COT. Conclusions: HFNC application after extubation is associated with reduced post-extubation 28-day mortality risks in acute respiratory failure patients who received planned extubation.

Serial biomarker measurements may be helpful to predict the successful application of high flow nasal cannula in COVID-19 pneumonia patients

High flow nasal cannula (HFNC) can reduce the need for intubation in patients with coronavirus disease-19 (COVID-19) pneumonia induced acute hypoxemic respiratory failure (AHRF), but predictors of HFNC success could be characterized better. C-reactive protein (CRP) and D-dimer are associated with COVID-19 severity and progression. However, no one has evaluated the use of serial CRP and D-dimer ratios to predict HFNC success. We retrospectively studied 194 HFNC-treated patients admitted between August 2020 and October 2022. CRP and D-dimer levels relative to baseline at HFNC initiation were calculated up to three days thereafter. Intubated and non-intubated patient comparisons were assessed by the Kruskal-Wallis rank sum test and t-test. Ninety-two patients were intubated and 102 were not. Median CRP ratios were lower in non-intubated versus intubated patients (0.69 v. 0.96, p = 0.050 for Day 1; 0.49 v. 0.61, p = 0.028 for Day 2; 0.33 v. 0.64, p = 0.008 for Day 3). D-dimer ratios did not change. CRP ratio monitoring in patients with AHRF due to COVID-19 within the first three days of HFNC application can serve as an objective adjunctive clinical tool to identify individuals who can continue to be supported with HFNC without escalating to invasive mechanical ventilation.

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

Diagnosis and Management of Acute Respiratory Failure

Acute hypoxemic respiratory failure is defined by Pao2 less than 60 mm Hg or SaO2 less than 88% and may result from V/Q mismatch, shunt, hypoventilation, diffusion limitation, or low inspired oxygen tension. Acute hypercapnic respiratory failure is defined by Paco2 ≥ 45 mm Hg and pH less than 7.35 and may result from alveolar hypoventilation, increased fraction of dead space, or increased production of carbon dioxide. Early diagnostic maneuvers, such as measurement of SpO2 and arterial blood gas, can differentiate the type of respiratory failure and guide next steps in evaluation and management.