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.

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.

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.

Clinical characteristics and outcome of critically ill COVID-19 patients with acute kidney injury: a single centre cohort study

BACKGROUND

Acute kidney injury (AKI) is a common manifestation among patients critically ill with SARS-CoV-2 infection (Coronavirus 2019) and is associated with significant morbidity and mortality. The pathophysiology of renal failure in this context is not fully understood, but likely to be multifactorial. The intensive care unit outcomes of patients following COVID-19 acute critical illness with associated AKI have not been fully explored. We conducted a cohort study to investigate the risk factors for acute kidney injury in patients admitted to and intensive care unit with COVID-19, its incidence and associated outcomes.

METHODS

We reviewed the medical records of all patients admitted to our adult intensive care unit suffering from SARS-CoV-2 infection from 14th March 2020 until 12th May 2020. Acute kidney injury was defined using the Kidney Disease Improving Global Outcome (KDIGO) criteria. The outcome analysis was assessed up to date as 3rd of September 2020.

RESULTS

A total of 81 patients admitted during this period. All patients had acute hypoxic respiratory failure and needed either noninvasive or invasive mechanical ventilatory support. Thirty-six patients (44%) had evidence of AKI (Stage I-33%, Stage II-22%, Renal Replacement Therapy (RRT)-44%). All patients with AKI stage III had RRT. Age, diabetes mellitus, immunosuppression, lymphopenia, high D-Dimer levels, increased APACHE II and SOFA scores, invasive mechanical ventilation and use of inotropic or vasopressor support were significantly associated with AKI. The peak AKI was at day 4 and mean duration of RRT was 12.5 days. The mortality was 25% for the AKI group compared to 6.7% in those without AKI. Among those received RRT and survived their illness, the renal function recovery is complete and back to baseline in all patients.

CONCLUSION

Acute kidney injury and renal replacement therapy is common in critically ill patients presenting with COVID-19. It is associated with increased severity of illness on admission to ICU, increased mortality and prolonged ICU and hospital length of stay. Recovery of renal function was complete in all survived patients.

Distribution of high sensitivity troponin taken without conventional clinical indications in critical care patients and its association with mortality

Background

High sensitivity troponin (hs-cTn) concentrations above the manufacturer's upper limit of normal (ULN) are frequently seen outside the context of MI, particularly in critical care units. The current evidence regarding the prognostic value of hs-cTn in critical care settings is discrepant.

Purpose

To describe the distribution of hs-cTn in a consecutive cohort of patients in critical care units, regardless of whether there is a conventional clinical indication, and the association of this distribution with clinical outcomes.

Methods

Consecutive patients admitted to three adult critical care units (cardiothoracic (CCU), general (GCU), neuroscience (NCU)) over a six month period had hs-cTnI tests performed serially throughout the admission, regardless of whether the supervising team felt there was a clinical indication. The results were nested and not revealed to patients or clinicians unless they were requested as part of routine care. The hs-cTnI results were correlated with parameters of clinical outcome.

Results

After excluding those diagnosed with a type 1 MI, there were 1,563 patients remaining in the study cohort (CCU 530, GCU 750, NCU 283). The median hs-cTnI was 77ng/L (IQR 11–1932ng/L, with 1081 (69.2%) patients above the manufacturer-provided ULN. Overall there was a bimodal distribution; GCU and NCU were positively skewed and CCU negatively skewed. Hs-cTnI concentrations above the ULN were associated with age, comorbidity, illness severity and need for organ support (table 1). The degree by which the hs-cTnI concentration was above the ULN remained an independent predictor of critical care mortality (figure 1) in NCU and GCU.

Conclusion

Hs-cTnI elevation taken outside the context of conventional clinical indications is common in the critically ill and is associated with age, comorbidity and illness severity. Admission hs-cTnI is an independent predictor of mortality and provides additional discriminative ability to the APACHE II score alone. This assay may represent a novel prognostic biomarker on admission in non-CCU critical care settings.

Mortality relative to ULN

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Beckman Coulter

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.

A phase I trial of the HSP90 inhibitor, alvespimycin (17-DMAG) administered weekly, intravenously, to patients with advanced, solid tumours

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Background: alvespimycin (17-dimethylaminoethylamino-17-demethoxygeldanamycin, 17-DMAG) inhibits N-terminal ATPase activity of Heat Shock Protein 90 (HSP90). Chaperone interactions are altered such that client proteins are targeted for degradation. The plethora of HSP90 client proteins offers the potential of simultaneous blockade across multiple, oncogenic signalling pathways. Methods: the maximum tolerated dose, at which ≤ 1/6 patients experienced dose limiting toxicity (DLT) was determined by dose-doubling (3+3) design. PK and PD biomarker data were used to define a biologically effective dose (BED). PK (LC/MS/MS) and PD (western blot) assays were validated and compliant with European clinical trial legislation. Cancer Research UK and the NCI were co-sponsors. Results: twenty five patients, median age 58 (range 38–78) years, received 475 infusions at doses between 2.5 and 106 mg/m2. Dose doubling was possible to 80mg/m2 when grade 2 toxicity, including dry eye and blurred vision (2/5 patients) occurred. At 106mg/m2 DLT were observed (grade 3 fatigue, diarrhoea, dehydration and grade 4 hypotension, AST rise) in 2/4 patients, one patient died from cardiac arrest. PK data were as follows; plasma t = 24.6 ± 8.6 hr, Vss 468 ± 383 L (mean ± SD) and clearance 27.7 L/hr (range 8.26 - 153). Maximum plasma concentration increased proportionally with alvespimycin dose, area under the curve was only linear ≤ 80 mg/m2. PD changes (HSP72 induction) in peripheral blood mononuclear cells were detected ≥ 20 mg/m2. HSP90 inhibition (client protein depletion and HSP72 induction) was not readily detected until 106 mg/m2. Tumour samples confirmed HSP90 inhibition 24 hours after 17-DMAG in 1/1 and 2/4 patients given 106 and 80 mg/m2, respectively. Two partial responses one, confirmed, in a patient with hormone refractory prostate cancer and one, investigator assessed, in a patient with melanoma occurred. Both remain on study after 27 and 18 months, respectively. Nine patients (36%) have been on trial ≥16 weeks. Conclusions: The recommended phase II dose of alvespimycin is 80 mg/m2 weekly. PK and PD data support this as a BED.

No significant financial relationships to disclose.

Discourse therapy in multilingual aphasia: a case study

Analysis of the strategies used in narrative and conversational discourse enables a sensitive evaluation of the deficit in mild aphasic patients and a possible alternative to the therapist dealing with multilingual patients for whom standard aphasia testing is not useful. This study describes the characterization of the communication deficit in a multilingual aphasic patient and the development and subsequent implementation of a therapy programme. Standard testing and discourse analysis took place in four languages, but therapy took place in English. Improvement in conversational skills was noted in all four languages and the patient reported increased functional ability, particularly in a work context. The implications of this approach to assessment and therapy are discussed.