Severe Parainfluenza Viral Infection-A Retrospective Study of Adult Intensive Care Patients.

There is little known about parainfluenza virus (PIV) infection in adult intensive care unit (ICU) patients. Here, we aim to describe the characteristics, clinical course and outcomes of PIV infection in adults requiring intensive care. In this retrospective study of consecutive patients admitted to our ICU with confirmed PIV infection over a 7-year period, we report the patient characteristics, laboratory tests and prognostic scores on ICU admission. The main outcomes reported are 30-day mortality and organ support required. We included 50 patients (52% male, mean age 67.6 years). The mean PaO2/FiO2 and neutrophil/lymphocyte ratios on ICU admission were 198 ± 82 mmHg and 15.7 ± 12.5. Overall, 98% of patients required respiratory support and 24% required cardiovascular support. The median length of ICU stay was 5.9 days (IQR 3.7-9.1) with a 30-day mortality of 40%. In conclusion, PIV infection in adult ICU patients is associated with significant mortality and morbidity. There were significant differences between patients who presented with primary hypoxemic respiratory failure and hypercapnic respiratory failure.

Prone Positioning in Mechanically Ventilated COVID-19 Patients: Timing of Initiation and Outcomes.

The COVID-19 pandemic led to a broad implementation of proning to enhance oxygenation in both self-ventilating and mechanically ventilated critically ill patients with acute severe hypoxic respiratory failure. However, there is little data on the impact of the timing of the initiation of prone positioning in COVID-19 patients receiving mechanical ventilation. In this study, we analyzed our proning practices in mechanically ventilated COVID-19 patients. There were 931 total proning episodes in 144 patients, with a median duration of 16 h (IQR 15-17 h) per proning cycle. 563 proning cycles were initiated within 7 days of intubation (early), 235 within 7-14 days (intermediate), and 133 after 14 days (late). The mean change in oxygenation defined as the delta PaO2/FiO2 ratio (ΔPF) after the prone episode was 16.6 ± 34.4 mmHg (p < 0.001). For early, intermediate, and late cycles, mean ΔPF ratios were 18.5 ± 36.7 mmHg, 13.2 ± 30.4 mmHg, and 14.8 ± 30.5 mmHg, with no significant difference in response between early, intermediate, and late proning (p = 0.2), respectively. Our findings indicate a favorable oxygenation response to proning episodes at all time points, even after >14 days of intubation. However, the findings cannot be translated directly into a survival advantage, and more research is needed in this area.

Non-Invasive Ventilation for Community-Acquired Pneumonia: Outcomes and Predictors of Failure from an ICU Cohort.

Background and Objectives: The use of non-invasive ventilation (NIV) for community-acquired pneumonia (CAP) remains controversial. NIV failure in the setting of acute hypoxemic respiratory failure is associated with increased mortality, highlighting the need for careful patient selection. Methods and Methods: This is a retrospective observational cohort study. We included 140 patients with severe CAP, treated with either NIV or invasive mechanical ventilation (IMV) as their primary oxygenation strategy. Results: The median PaO2/FiO2 ratio and SOFA score upon ICU admission were 151 mmHg and 6, respectively. We managed 76% of patients with NIV initially and report an NIV success rate of 59%. Overall, the 28-day mortality was 25%, whilst for patients with NIV success, the mortality was significantly lower at 13%. In the univariate analysis, NIV failure was associated with the SOFA score (OR 1.33), the HACOR score (OR 1.14) and the presence of septic shock (OR 3.99). The SOFA score has an AUC of 0.75 for NIV failure upon ICU admission, whilst HACOR has an AUC of 0.76 after 2 h of NIV. Conclusions: Our results suggest that a SOFA ≤ 4 and an HACOR ≤ 5 are reasonable thresholds to identify patients with severe CAP likely to benefit from NIV.

Detailed Analysis of Primary Non-invasive Respiratory Support and Outcomes of Subjects With COVID-19 Acute Hypoxaemic Respiratory Failure.

Background The role of non-invasive (continuous positive airway pressure (CPAP) or Non-invasive ventilation (NIV)) respiratory support (NIRS) as a primary oxygenation strategy for COVID-19 patients with acute severe hypoxic respiratory failure (AHRF), as opposed to invasive mechanical ventilation (invasive-MV), is uncertain. While NIRS may prevent complications related to invasive MV, prolonged NIRS and delays in intubation may lead to adverse outcomes. This study was conducted to assess the role of NIRS in COVID-19 hypoxemic respiratory failure and to explore the variables associated with NRIS failure. Methods This is a single-center, observational study of two distinct waves of severe COVID-19 patients admitted to the ICU. Patients initially managed with non-invasive respiratory support with laboratory-confirmed SARS-CoV-2 in acute hypoxaemic respiratory failure were included. Demographics, comorbidities, admission laboratory variables, and ICU admission scores were extracted from electronic health records. Univariate and multiple logistic regression was used to identify predictive factors for invasive mechanical ventilation. Kaplan-Meier survival curves were used to summarise survival between the ventilatory and time-to-intubation groups. Results There were 291 patients, of which 232 were managed with NIRS as an initial ventilation strategy. There was a high incidence of failure (48.7%). Admission APACHE II score, SOFA score, HACOR score, ROX index, and PaO2/FiO2 were all predictive of NIRS failure. Daily (days 1-4) HACOR scores and ROX index measurements highly predicted NIRS failure. Late NIRS failure (>24 hours) was independently associated with increased mortality (44%). Conclusion NIRS is effective as first-line therapy for COVID-19 patients with AHRF. However, failure, particularly delayed failure, is associated with significant mortality. Early prediction of NIRS failure may prevent adverse outcomes.

Body mass index and clinical outcome of severe COVID-19 patients with acute hypoxic respiratory failure: Unravelling the "obesity paradox" phenomenon.

BACKGROUND AND AIMS: Although obesity have been generally shown to be an independent risk factor for poor outcomes in COVID-19 infection, some studies demonstrate a paradoxical protective effect ("obesity paradox"). This study examines the influence of obesity categories on clinical outcomes of severe COVID-19 patients admitted to an intensive care unit with acute hypoxic respiratory failure requiring either non-invasive or invasive mechanical ventilation. METHODS: This is a single centre, retrospective study of consecutive COVID-19 patients admitted to the intensive care unit between 03/2020 to 03/2021. Patients were grouped according to the NICE Body Mass Index (BMI) category. Admission variables including age, sex, comorbidities, and ICU severity indices (APACHE-II, SOFA and PaO2/FiO2) were collected. Data were compared between BMI groups for outcomes such as need for invasive mechanical ventilation (IMV), renal replacement therapy (RRT) and 28-day and overall hospital mortality. RESULTS: 340 patients were identified and of those 333 patients had their BMI documented. Just over half of patients (53%) had obesity. Those with extreme obesity (obesity groups II and III) were younger with fewer comorbidities, but were more hypoxaemic at presentation, than the healthy BMI group. Although non-significant, obesity groups II and III paradoxically showed a lower in-hospital mortality than the healthy weight group. However, adjusted (age, sex, APACHE-II and CCI) competing risk regression analysis showed three-times higher mortality in obese category I (sub-distribution hazard ratio = 3.32 (95% CI 1.30-8.46), p = 0.01) and a trend to higher mortality across all obesity groups compared to the healthy weight group. CONCLUSIONS: In this cohort, those with obesity were at higher risk of mortality after adjustment for confounders. We did not identify an "obesity paradox" in this cohort. The obesity paradox may be explained by confounding factors such as younger age, fewer comorbidities, and less severe organ failures. The impact of obesity on indicators of morbidity including likelihood of requirement for organ support measures was not conclusively demonstrated and requires further scrutiny.

Dynamic blood oxygen indices in mechanically ventilated COVID-19 patients with acute hypoxic respiratory failure: A cohort study.

BACKGROUND: Acute hypoxic respiratory failure (AHRF) is a hallmark of severe COVID-19 pneumonia and often requires supplementary oxygen therapy. Critically ill COVID-19 patients may require invasive mechanical ventilation, which carries significant morbidity and mortality. Understanding of the relationship between dynamic changes in blood oxygen indices and clinical variables is lacking. We evaluated the changes in blood oxygen indices-PaO2, PaO2/FiO2 ratio, oxygen content (CaO2) and oxygen extraction ratio (O2ER) in COVID-19 patients through the first 30-days of intensive care unit admission and explored relationships with clinical outcomes. METHODS AND FINDINGS: We performed a retrospective observational cohort study of all adult COVID-19 patients in a single institution requiring invasive mechanical ventilation between March 2020 and March 2021. We collected baseline characteristics, clinical outcomes and blood oxygen indices. 36,383 blood gas data points were analysed from 184 patients over 30-days. Median participant age was 59.5 (IQR 51.0, 67.0), BMI 30.0 (IQR 25.2, 35.5) and the majority were men (62.5%) of white ethnicity (70.1%). Median duration of mechanical ventilation was 15-days (IQR 8, 25). Hospital survival at 30-days was 72.3%. Non-survivors exhibited significantly lower PaO2 throughout intensive care unit admission: day one to day 30 averaged mean difference -0.52 kPa (95% CI: -0.59 to -0.46, p<0.01). Non-survivors exhibited a significantly lower PaO2/FiO2 ratio with an increased separation over time: day one to day 30 averaged mean difference -5.64 (95% CI: -5.85 to -5.43, p<0.01). While all patients had sub-physiological CaO2, non-survivors exhibited significantly higher values. Non-survivors also exhibited significantly lower oxygen extraction ratio with an averaged mean difference of -0.08 (95% CI: -0.09 to -0.07, p<0.01) across day one to day 30. CONCLUSIONS: As a novel cause of acute hypoxic respiratory failure, COVID-19 offers a unique opportunity to study a homogenous cohort of patients with hypoxaemia. In mechanically ventilated adult COVID-19 patients, blood oxygen indices are abnormal with substantial divergence in PaO2/FiO2 ratio and oxygen extraction ratio between survivors and non-survivors. Despite having higher CaO2 values, non-survivors appear to extract less oxygen implying impaired oxygen utilisation. Further exploratory studies are warranted to evaluate and improve oxygen extraction which may help to improve outcomes in severe hypoxaemic mechanically ventilated COVID-19 patients.

Distribution of High-Sensitivity Troponin Taken Without Conventional Clinical Indications in Critical Care Patients and Its Association With Mortality.

OBJECTIVES: To describe the distribution of high-sensitivity troponin in a consecutive cohort of patients in critical care units, regardless of clinical indication, and its association with clinical outcomes. DESIGN: Prospective observational study. SETTING: Single-center teaching hospital. PATIENTS: Consecutive patients admitted to two adult critical care units (general critical care unit and neuroscience critical care unit) over a 6-month period. INTERVENTIONS: All patients had high-sensitivity troponin tests performed at admission and tracked throughout their critical care stay, regardless of whether the supervising team felt there was a clinical indication. The results were not revealed to patients or clinicians unless clinically requested. MEASUREMENTS AND MAIN RESULTS: There were 1,033 patients in the study cohort (general critical care unit 750 and neuroscience critical care unit 283). The median high-sensitivity troponin was 21 ng/L (interquartile range, 7-86 ng/L), with 560 patients (54.2%) above the upper limit of normal as defined by the manufacturer. Admission high-sensitivity troponin concentrations above the upper limit of normal in general critical care unit and neuroscience critical care unit were associated with increasing age, comorbidity, markers of illness severity, and the need for organ support. On adjusted analysis, the high-sensitivity troponin concentration remained an independent predictor of critical care mortality in general critical care unit and neuroscience critical care unit. CONCLUSIONS: High-sensitivity troponin elevation, taken outside the context of conventional clinical indications, was common in the critically ill. Such elevations were associated with increasing age, comorbidity, illness severity, and the need for organ support. Admission high-sensitivity troponin concentration is an independent predictor of critical care mortality and as such may represent a novel prognostic biomarker at admission.

Conscious prone positioning during non-invasive ventilation in COVID-19 patients: experience from a single centre.

Critically ill patients admitted to hospital following SARS-CoV-2 infection often experience hypoxic respiratory failure and a proportion require invasive mechanical ventilation to maintain adequate oxygenation. The combination of prone positioning and non-invasive ventilation in conscious patients may have a role in improving oxygenation. The purpose of this study was to assess the effect of prone positioning in spontaneously ventilating patients receiving non-invasive ventilation admitted to the intensive care.  Clinical data of 81 patients admitted with COVID 19 pneumonia and acute hypoxic respiratory failure were retrieved from electronic medical records and examined. Patients who had received prone positioning in combination with non-invasive ventilation were identified. A total of 20 patients received prone positioning in conjunction with non-invasive ventilation. This resulted in improved oxygenation as measured by a change in PaO 2/FiO 2 (P/F) ratio of 28.7 mmHg while prone, without significant change in heart rate or respiratory rate. Patients on average underwent 5 cycles with a median duration of 3 hours. There were no reported deaths, 7 of the 20 patients (35%) failed non-invasive ventilation and subsequently required intubation and mechanical ventilation. In our cohort of 20 COVID-19 patients with moderate acute hypoxic respiratory failure, prone positioning with non-invasive ventilation resulted in improved oxygenation. Prone positioning with non-invasive ventilation may be considered as an early therapeutic intervention in COVID-19 patients with moderate acute hypoxic respiratory failure.