A novel speckle-tracking echocardiography parameter assessing left ventricular afterload.

BACKGROUND: Left ventricular stroke work index (LVSWI) and afterload-related cardiac performance (ACP) consider left ventricular (LV) afterload and could be better prognosticators in septic cardiomyopathy. However, their invasive nature prevents their routine clinical applications. This study aimed to investigate (1) whether a proposed speckle-tracking echocardiography parameter, Pressure-Strain Product (PSP), can non-invasively predict catheter-based LVSWI, ACP and serum lactate in an ovine model of septic cardiomyopathy; and (2) whether PSP can distinguish the sub-phenotypes of acute respiratory distress syndrome (ARDS) with or without sepsis-like conditions. METHODS: Sixteen sheep with ARDS were randomly assigned to either (1) sepsis-like (n = 8) or (2) non-sepsis-like (n = 8) group. Each ARDS and sepsis-like condition was induced by intravenous infusion of oleic acid and lipopolysaccharide, respectively. Pulmonary artery catheter-based LVSWI (the product of stroke work index, mean arterial pressure and .0136), ACP (the percentage of cardiac output measured to cardiac output predicted as normal) and serum lactate were measured simultaneously with transthoracic echocardiography. Two PSP indices were calculated by multiplying the mean arterial blood pressure and either global circumferential strain (PSPcirc) or radial strain (PSPrad). RESULTS: PSPcirc showed a significant correlation with LVSWI (r2 = .66, p < .001) and ACP (r2 = .82, p < .001) in the sepsis-like group. Although PSP could not distinguish subphenotypes, PSPcirc predicted LVSWI (AUC .86) and ACP (AUC .88), and PSPrad predicted serum lactate (AUC .75) better than LV ejection fraction, global circumferential and radial strain. CONCLUSIONS: A novel PSP has the potential to non-invasively predict catheter-based LVSWI and ACP, and was associated with serum lactate in septic cardiomyopathy.

A novel echocardiographic parameter considering left ventricular afterload during V-A ECMO support.

BACKGROUND: Left ventricular stroke work index (LVSWI) and cardiac power index (CPI) account for the haemodynamic load of the left ventricle and are promising prognostic values in cardiogenic shock. However, accurately and non-invasively measuring these parameters during veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is challenging and potentially biased by the extracorporeal circulation. This study aimed to investigate, in an ovine model of cardiogenic shock, whether Pressure-Strain Product (PSP), a novel speckle-tracking echocardiography parameter, (1) can correlate with pressure-volume catheter-based LVSWI and CPI, and (2) can be load-independent during the flow modification of V-A ECMO. METHODS: Nine Dorset-cross ewes (51 ± 4 kg) were included. After cardiogenic shock was induced, full support V-A ECMO (X L/min based on 60 mL/kg/min) commenced. At seven time points during 24-h observation, echocardiographic parameters as well as pressure-volume catheter-based LVSWI and CPI were simultaneously measured with X and following X-1 L/min of ECMO flow. PSP was calculated by multiplying global circumferential strain or global radial strain, and mean arterial pressure, for PSPcirc or PSPrad, respectively. RESULTS: PSPcirc showed a stronger correlation with LVSWI (correlation coefficient, CC = .360, p < .001) and CPI (CC = .283, p < .001) than other echocardiographic parameters. The predictability of PSPcirc for pressure-volume catheter-based LVSWI (AUC .82) and CPI (AUC .80) was also higher than other echocardiographic parameters. No statistically significant differences were identified between the two ECMO flow variations in PSPcirc (p = .558). CONCLUSIONS: A novel echocardiographic parameter, PSP, may non-invasively predict pressure-volume catheter-based LVSWI and CPI in a load-independent manner in a cardiogenic shock supported by V-A ECMO.

Echocardiographic surrogate of left ventricular stroke work in a model of brain stem death donors.

BACKGROUND: The commonest echocardiographic measurement, left ventricular ejection fraction, can not necessarily predict mortality of recipients following heart transplantation potentially due to afterload dependency. Afterload-independent left ventricular stroke work index (LVSWI) is alternatively recommended by the current guideline; however, pulmonary artery catheters are rarely inserted in organ donors in most jurisdictions. We propose a novel non-invasive echocardiographic parameter, Pressure-Strain Product (PSP), as a potential surrogate of catheter-based LVSWI. This study aimed to investigate if PSP could correlate with catheter-based LVSWI in an ovine model of brain stem death (BSD) donors. The association between PSP and myocardial mitochondrial function in the post-transplant hearts was also evaluated. METHODS: Thirty-one female sheep (weight 47 ± 5 kg) were divided into two groups; BSD (n = 15), and sham neurologic injury (n = 16). Echocardiographic parameters including global circumferential strain (GCS) and global radial strain (GRS) and pulmonary artery catheter-based LVSWI were simultaneously measured at 8-timepoints during 24-h observation. PSP was calculated as a product of GCS or GRS, and mean arterial pressure for PSPcirc or PSPrad, respectively. Myocardial mitochondrial function was evaluated following 6-h observation after heart transplantation. RESULTS: In BSD donor hearts, PSPcirc (n = 96, rho = .547, p < .001) showed the best correlation with LVSWI among other echocardiographic parameters. PSPcirc returned AUC of .825 to distinguish higher values of cardiomyocyte mitochondrial function (cut-off point; mean value of complex 1,2 O2 Flux) in post-transplant hearts, which was greater than other echocardiographic parameters. CONCLUSIONS: PSPcirc could be used as a surrogate of catheter-based LVSWI reflecting mitochondrial function.

Neurological manifestations of COVID-19 in adults and children.

Different neurological manifestations of coronavirus disease 2019 (COVID-19) in adults and children and their impact have not been well characterized. We aimed to determine the prevalence of neurological manifestations and in-hospital complications among hospitalized COVID-19 patients and ascertain differences between adults and children. We conducted a prospective multicentre observational study using the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) cohort across 1507 sites worldwide from 30 January 2020 to 25 May 2021. Analyses of neurological manifestations and neurological complications considered unadjusted prevalence estimates for predefined patient subgroups, and adjusted estimates as a function of patient age and time of hospitalization using generalized linear models. Overall, 161 239 patients (158 267 adults; 2972 children) hospitalized with COVID-19 and assessed for neurological manifestations and complications were included. In adults and children, the most frequent neurological manifestations at admission were fatigue (adults: 37.4%; children: 20.4%), altered consciousness (20.9%; 6.8%), myalgia (16.9%; 7.6%), dysgeusia (7.4%; 1.9%), anosmia (6.0%; 2.2%) and seizure (1.1%; 5.2%). In adults, the most frequent in-hospital neurological complications were stroke (1.5%), seizure (1%) and CNS infection (0.2%). Each occurred more frequently in intensive care unit (ICU) than in non-ICU patients. In children, seizure was the only neurological complication to occur more frequently in ICU versus non-ICU (7.1% versus 2.3%, P < 0.001). Stroke prevalence increased with increasing age, while CNS infection and seizure steadily decreased with age. There was a dramatic decrease in stroke over time during the pandemic. Hypertension, chronic neurological disease and the use of extracorporeal membrane oxygenation were associated with increased risk of stroke. Altered consciousness was associated with CNS infection, seizure and stroke. All in-hospital neurological complications were associated with increased odds of death. The likelihood of death rose with increasing age, especially after 25 years of age. In conclusion, adults and children have different neurological manifestations and in-hospital complications associated with COVID-19. Stroke risk increased with increasing age, while CNS infection and seizure risk decreased with age.

Transcriptomic profiling of cardiac tissues from SARS-CoV-2 patients identifies DNA damage.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to present with pulmonary and extra-pulmonary organ complications. In comparison with the 2009 pandemic (pH1N1), SARS-CoV-2 infection is likely to lead to more severe disease, with multi-organ effects, including cardiovascular disease. SARS-CoV-2 has been associated with acute and long-term cardiovascular disease, but the molecular changes that govern this remain unknown. In this study, we investigated the host transcriptome landscape of cardiac tissues collected at rapid autopsy from seven SARS-CoV-2, two pH1N1, and six control patients using targeted spatial transcriptomics approaches. Although SARS-CoV-2 was not detected in cardiac tissue, host transcriptomics showed upregulation of genes associated with DNA damage and repair, heat shock, and M1-like macrophage infiltration in the cardiac tissues of COVID-19 patients. The DNA damage present in the SARS-CoV-2 patient samples, were further confirmed by γ-H2Ax immunohistochemistry. In comparison, pH1N1 showed upregulation of interferon-stimulated genes, in particular interferon and complement pathways, when compared with COVID-19 patients. These data demonstrate the emergence of distinct transcriptomic profiles in cardiac tissues of SARS-CoV-2 and pH1N1 influenza infection supporting the need for a greater understanding of the effects on extra-pulmonary organs, including the cardiovascular system of COVID-19 patients, to delineate the immunopathobiology of SARS-CoV-2 infection, and long term impact on health.

Morbid obesity's impact on COVID-19 patients requiring venovenous extracorporeal membrane oxygenation: The covid-19 critical care consortium database review.

Introduction: Obesity is associated with a worse prognosis in COVID-19 patients with acute respiratory distress syndrome (ARDS). Veno-venous (V-V) Extracorporeal Membrane Oxygenation (ECMO) can be a rescue option, however, the direct impact of morbid obesity in this select group of patients remains unclear.Methods: This is an observational study of critically ill adults with COVID-19 and ARDS supported by V-V ECMO. Data are from 82 institutions participating in the COVID-19 Critical Care Consortium international registry. Patients were admitted between 12 January 2020 to 27 April 2021. They were stratified based on Body Mass Index (BMI) at 40 kg/m2. The endpoint was survival to hospital discharge.Results: Complete data available on 354 of 401 patients supported on V-V ECMO. The characteristics of the high BMI (>40 kg/m2) and lower BMI (≤40 kg/m2) groups were statistically similar. However, the 'high BMI' group were comparatively younger and had a lower APACHE II score. Using survival analysis, older age (Hazard Ratio, HR 1.49 per-10-years, CI 1.25-1.79) and higher BMI (HR 1.15 per-5 kg/m2 increase, CI 1.03-1.28) were associated with a decreased patient survival. A safe BMI threshold above which V-V ECMO would be prohibitive was not apparent and instead, the risk of an adverse outcome increased linearly with BMI.Conclusion: In COVID-19 patients with severe ARDS who require V-V ECMO, there is an increased risk of death associated with age and BMI. The risk is linear and there is no BMI threshold beyond which the risk for death greatly increases.

Beneficial Effect of Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019.

OBJECTIVES: The study investigated the impact of prone positioning during venovenous extracorporeal membrane oxygenation support for coronavirus disease 2019 acute respiratory failure on the patient outcome. DESIGN: An observational study of venovenous extracorporeal membrane oxygenation patients. We used a multistate survival model to compare the outcomes of patients treated with or without prone positioning during extracorporeal membrane oxygenation, which incorporates the dynamic nature of prone positioning and adjusts for potential confounders. SETTING: Seventy-two international institutions participating in the Coronavirus Disease 2019 Critical Care Consortium international registry. PATIENTS: Coronavirus disease 2019 patients who were supported by venovenous extracorporeal membrane oxygenation during the study period. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: There were 232 coronavirus disease 2019 patients at 72 participating institutions who were supported with venovenous extracorporeal membrane oxygenation during the study period from February 16, 2020, to October 31, 2020. Proning was used in 176 patients (76%) before initiation of extracorporeal membrane oxygenation and in 67 patients (29%) during extracorporeal membrane oxygenation. Survival to hospital discharge was 33% in the extracorporeal membrane oxygenation prone group versus 22% in the extracorporeal membrane oxygenation supine group. Prone positioning during extracorporeal membrane oxygenation support was associated with reduced mortality (hazard ratio, 0.31; 95% CI, 0.14-0.68). CONCLUSIONS: Our study highlights that prone positioning during venovenous extracorporeal membrane oxygenation support for refractory coronavirus disease 2019-related acute respiratory distress syndrome is associated with reduced mortality. Given the observational nature of the study, a randomized controlled trial of prone positioning on venovenous extracorporeal membrane oxygenation is needed to confirm these findings.

Tracheostomy outcomes in critically ill patients with COVID-19: a systematic review, meta-analysis, and meta-regression.

BACKGROUND: We performed a systematic review of mechanically ventilated patients with COVID-19, which analysed the effect of tracheostomy timing and technique (surgical vs percutaneous) on mortality. Secondary outcomes included intensive care unit (ICU) and hospital length of stay (LOS), decannulation from tracheostomy, duration of mechanical ventilation, and complications. METHODS: Four databases were screened between January 1, 2020 and January 10, 2022 (PubMed, Embase, Scopus, and Cochrane). Papers were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Population or Problem, Intervention or exposure, Comparison, and Outcome (PICO) guidelines. Meta-analysis and meta-regression for main outcomes were performed. RESULTS: The search yielded 9024 potentially relevant studies, of which 47 (n=5268 patients) were included. High levels of between-study heterogeneity were observed across study outcomes. The pooled mean tracheostomy timing was 16.5 days (95% confidence interval [CI]: 14.7-18.4; I2=99.6%). Pooled mortality was 22.1% (95% CI: 18.7-25.5; I2=89.0%). Meta-regression did not show significant associations between mortality and tracheostomy timing, mechanical ventilation duration, time to decannulation, and tracheostomy technique. Pooled mean estimates for ICU and hospital LOS were 29.6 (95% CI: 24.0-35.2; I2=98.6%) and 38.8 (95% CI: 32.1-45.6; I2=95.7%) days, both associated with mechanical ventilation duration (coefficient 0.8 [95% CI: 0.2-1.4], P=0.02 and 0.9 [95% CI: 0.4-1.4], P=0.01, respectively) but not tracheostomy timing. Data were insufficient to assess tracheostomy technique on LOS. Duration of mechanical ventilation was 23.4 days (95% CI: 19.2-27.7; I2=99.3%), not associated with tracheostomy timing. Data were insufficient to assess the effect of tracheostomy technique on mechanical ventilation duration. Time to decannulation was 23.8 days (95% CI: 19.7-27.8; I2=98.7%), not influenced by tracheostomy timing or technique. The most common complications were stoma infection, ulcers or necrosis, and bleeding. CONCLUSIONS: In patients with COVID-19 requiring tracheostomy, the timing and technique of tracheostomy did not clearly impact on patient outcomes. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42021272220.

Impact of renin-angiotensin-aldosterone system inhibition on mortality in critically ill COVID-19 patients with pre-existing hypertension: a prospective cohort study.

BACKGROUND: The influence of renin-angiotensin-aldosterone system (RAAS) inhibitors on the critically ill COVID-19 patients with pre-existing hypertension remains uncertain. This study examined the impact of previous use of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) on the critically ill COVID-19 patients. METHODS: Data from an international, prospective, observational cohort study involving 354 hospitals spanning 54 countries were included. A cohort of 737 COVID-19 patients with pre-existing hypertension admitted to intensive care units (ICUs) in 2020 were targeted. Multi-state survival analysis was performed to evaluate in-hospital mortality and hospital length of stay up to 90 days following ICU admission. RESULTS: A total of 737 patients were included-538 (73%) with pre-existing hypertension had received ACEi/ARBs before ICU admission, while 199 (27%) had not. Cox proportional hazards model showed that previous ACEi/ARB use was associated with a decreased hazard of in-hospital death (HR, 0.74, 95% CI 0.58-0.94). Sensitivity analysis adjusted for propensity scores showed similar results for hazards of death. The average length of hospital stay was longer in ACEi/ARB group with 21.2 days (95% CI 19.7-22.8 days) in ICU and 6.7 days (5.9-7.6 days) in general ward compared to non-ACEi/ARB group with 16.2 days (14.1-18.6 days) and 6.4 days (5.1-7.9 days), respectively. When analysed separately, results for ACEi or ARB patient groups were similar for both death and discharge. CONCLUSIONS: In critically ill COVID-19 patients with comorbid hypertension, use of ACEi/ARBs prior to ICU admission was associated with a reduced risk of in-hospital mortality following adjustment for baseline characteristics although patients with ACEi/ARB showed longer length of hospital stay. Clinical trial registration The registration number: ACTRN12620000421932; The date of registration: 30, March 2020; The URL of the registration: https://www.australianclinicaltrials.gov.au/anzctr/trial/ACTRN12620000421932 .

Ischemic and Hemorrhagic Stroke Among Critically Ill Patients With Coronavirus Disease 2019: An International Multicenter Coronavirus Disease 2019 Critical Care Consortium Study.

OBJECTIVES: Stroke has been reported in observational series as a frequent complication of coronavirus disease 2019, but more information is needed regarding stroke prevalence and outcomes. We explored the prevalence and outcomes of acute stroke in an international cohort of patients with coronavirus disease 2019 who required ICU admission. DESIGN: Retrospective analysis of prospectively collected database. SETTING: A registry of coronavirus disease 2019 patients admitted to ICUs at over 370 international sites was reviewed for patients diagnosed with acute stroke during their stay. PATIENTS: Patients older than 18 years old with acute coronavirus disease 2019 infection in ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 2,699 patients identified (median age 59 yr; male 65%), 59 (2.2%) experienced acute stroke: 0.7% ischemic, 1.0% hemorrhagic, and 0.5% unspecified type. Systemic anticoagulant use was not associated with any stroke type. The frequency of diabetes, hypertension, and smoking was higher in patients with ischemic stroke than in stroke-free and hemorrhagic stroke patients. Extracorporeal membrane oxygenation support was more common among patients with hemorrhagic (56%) and ischemic stroke (16%) than in those without stroke (10%). Extracorporeal membrane oxygenation patients had higher cumulative 90-day probabilities of hemorrhagic (relative risk = 10.5) and ischemic stroke (relative risk = 1.7) versus nonextracorporeal membrane oxygenation patients. Hemorrhagic stroke increased the hazard of death (hazard ratio = 2.74), but ischemic stroke did not-similar to the effects of these stroke types seen in noncoronavirus disease 2019 ICU patients. CONCLUSIONS: In an international registry of ICU patients with coronavirus disease 2019, stroke was infrequent. Hemorrhagic stroke, but not ischemic stroke, was associated with increased mortality. Further, both hemorrhagic stroke and ischemic stroke were associated with traditional vascular risk factors. Extracorporeal membrane oxygenation use was strongly associated with both stroke and death.

Comparative efficacy of linezolid and vancomycin for endotracheal tube MRSA biofilms from ICU patients.

PURPOSE: To compare the efficacy of systemic treatment with linezolid (LNZ) versus vancomycin (VAN) on methicillin-resistant Staphylococcus aureus (MRSA) burden and eradication in endotracheal tube (ETT) biofilm and ETT cuff from orotracheally intubated patients with MRSA respiratory infection. METHODS: Prospective observational clinical study was carried out at four European tertiary hospitals. Plasma and endotracheal aspirate (ETA) levels of LNZ and VAN were determined 72 h after treatment initiation through high-performance liquid chromatography or bioassay. LNZ or VAN concentration in the ETT biofilm and MRSA burden and eradication was determined upon extubation. The minimum inhibitory concentration (MIC) for LNZ and VAN was assessed by E-test strips (Biomerieux®). Scanning electron microscopy images were obtained, and ETT biofilm thickness was compared between groups. RESULTS: Twenty-five patients, 15 treated with LNZ and 10 with VAN, were included in the study. LNZ presented a significantly higher concentration (µg/mL) than VAN in ETT biofilm (72.8 [1.3-127.1] vs 0.4 [0.4-1.3], p < 0.001), although both drugs achieved therapeutic plasma levels 72 h after treatment initiation. Systemic treatment with LNZ achieved lower ETT cuff MRSA burdens than systemic treatment with VAN. Indeed, LNZ increased the MRSA eradication rate in ETT cuff compared with VAN (LNZ 75%, VAN 20%, p = 0.031). CONCLUSIONS: In ICU patients with MRSA respiratory infection intubated for long periods, systemic treatment with LNZ obtains a greater beneficial effect than VAN in limiting MRSA burden in ETT cuff.

New Sepsis Definition (Sepsis-3) and Community-acquired Pneumonia Mortality. A Validation and Clinical Decision-Making Study.

RATIONALE: The Sepsis-3 Task Force updated the clinical criteria for sepsis, excluding the need for systemic inflammatory response syndrome (SIRS) criteria. The clinical implications of the proposed flowchart including the quick Sequential (Sepsis-related) Organ Failure Assessment (qSOFA) and SOFA scores are unknown. OBJECTIVES: To perform a clinical decision-making analysis of Sepsis-3 in patients with community-acquired pneumonia. METHODS: This was a cohort study including adult patients with community-acquired pneumonia from two Spanish university hospitals. SIRS, qSOFA, the Confusion, Respiratory Rate and Blood Pressure (CRB) score, modified SOFA (mSOFA), the Confusion, Urea, Respiratory Rate, Blood Pressure and Age (CURB-65) score, and Pneumonia Severity Index (PSI) were calculated with data from the emergency department. We used decision-curve analysis to evaluate the clinical usefulness of each score and the primary outcome was in-hospital mortality. MEASUREMENTS AND MAIN RESULTS: Of 6,874 patients, 442 (6.4%) died in-hospital. SIRS presented the worst discrimination, followed by qSOFA, CRB, mSOFA, CURB-65, and PSI. Overall, overestimation of in-hospital mortality and miscalibration was more evident for qSOFA and mSOFA. SIRS had lower net benefit than qSOFA and CRB, significantly increasing the risk of over-treatment and being comparable with the "treat-all" strategy. PSI had higher net benefit than mSOFA and CURB-65 for mortality, whereas mSOFA seemed more applicable when considering mortality/intensive care unit admission. Sepsis-3 flowchart resulted in better identification of patients at high risk of mortality. CONCLUSIONS: qSOFA and CRB outperformed SIRS and presented better clinical usefulness as prompt tools for patients with community-acquired pneumonia in the emergency department. Among the tools for a comprehensive patient assessment, PSI had the best decision-aid tool profile.

Body Position and Ventilator-Associated Pneumonia Prevention.

Seminal studies have demonstrated that tracheally intubated, mechanically ventilated patients, positioned in supine horizontal position, are at a high risk of developing ventilator-associated pneumonia, through aspiration of gastric pathogens. In the 1990s, innovative clinical findings promoted a radical change in practice, through the use of the semirecumbent position in all mechanically ventilated patients. Here, we critically review the main indications, pulmonary effects, and controversies on the use of the semirecumbent position. Also, we will depict potential roles of prone and lateral positions in the prevention of ventilator-associated pneumonia. Our review will span from preclinical experimental insights to clinical evidence, and we will discuss potential controversies on the use of the semirecumbent position as the standard of care. We will also detail potential alternatives to ultimately improve outcomes of tracheally intubated and mechanically ventilated patients.

Ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is an iatrogenic pulmonary infection that develops in tracheally intubated patients on mechanical ventilation for at least 48 hours. VAP is the nosocomial infection with the greatest impact on patient outcomes and health care costs. Endogenous colonization by aerobic gram-negative pathogens, that is, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus play a pivotal role in the pathogenesis of VAP. Several preventive strategies have shown efficacy in decreasing VAP incidence and are often implemented altogether as a prevention bundle. In patients with clinical suspicion of VAP, respiratory samples should be promptly collected. The empiric treatment should be based on the local prevalence of pathogens, duration of hospital stay, and prior antimicrobial therapy. The antibiotics can be stopped or adjusted to more narrow-spectrum once cultures and susceptibilities are available.

The efficacy of telavancin in comparison with linezolid on endotracheal tube biofilm in pigs with methicillin-resistant Staphylococcus aureus pneumonia.

BACKGROUND: The effect of systemic treatment of ventilator-associated pneumonia (VAP) with telavancin, a semisynthetic lipoglycopeptide with good penetration in vitro biofilms, has not been tested in vivo during mechanical ventilation. This study examined the efficacy of telavancin compared with linezolid against endotracheal tube (ETT) biofilms in a porcine model of methicillin-resistant Staphylococcus aureus (MRSA) VAP. METHODS: VAP was induced in 18 pigs by instilling 107 colony-forming units (CFU/mL) of an MRSA strain susceptible to telavancin and linezolid into each pulmonary lobe. Randomization into three groups was done at pneumonia diagnosis: control (IV glucose 0.5% solution q24); linezolid (10 mg/kg q12) and telavancin groups (22.5 mg/kg q24). After 72 h of MV, data regarding bronchoalveolar lavage (BAL), tracheal aspirate (TA), ETT MRSA biofilm load and thickness measured by scanning electron microscopy were obtained. RESULTS: All 18 pigs completed the study. MRSA was isolated in 100% of ETTs from the control and linezolid groups and in 67% from the telavancin group. Telavancin treatment presented a lower MRSA load compared to the control and linezolid treatments (telavancin median [interquartile range (IQR)] = 1.94 [0.00-5.45], linezolid 3.99 [3.22-4.68] and control 4.93 [4.41-5.15], P = 0.236). Telavancin treatment also resulted in the lowest biofilm thickness according to the SEM (4.04 [2.09-6.00], P < 0.001). We found a positive correlation between ETT and BAL load (rho = 0.511, P = 0.045). CONCLUSIONS: In our VAP model, systemic telavancin treatment reduced ETT MRSA occurrence, load, and biofilm thickness. Our findings may have a bearing on ICU patients' clinical outcomes.

Variability of oxygen requirements in critically ill COVID-19 patients.

Background: The global scarcity of medical oxygen has proven to be catastrophic during the surges in COVID-19 cases over the past two years, with the heaviest burden felt in low- and middle-income countries. Despite its criticality, data and analyses of oxygen consumption, even for typical clinical cases, are missing. Consequently, planning oxygen needs, particularly with variable surges in COVID-19 cases, has presented a substantial challenge to policymakers and hospital decision-makers. Methods: We performed a sub-analysis of the COVID-19 Critical Care Consortium database assessing the oxygen consumption requirements of COVID-19 patients admitted to intensive care units between February 2020 and October 2021. We calculated descriptive statistics for oxygen flow-rates, stratified by oxygen supplementation method, and developed a multi-state model for estimating the frequency, therapy duration, probability of transition, and number of oxygen therapy modes per patient. Results: Overall, 12 429 patients from 35 countries received oxygen support on at least one day of their hospitalisation. Of the patients with measurable flow rates, 6142 received invasive mechanical ventilation, 838 received high-flow nasal oxygen, and 257 received both modalities. The median flow rate for mechanical ventilation was 3.2 L per minute (interquartile range (IQR) = 2.0-4.9), with a median duration of 12 days (IQR = 6-24), while the median flow rate for high-flow nasal cannula was 40 L per minute (IQR = 15-55), with a median duration of three days (IQR = 2-6). Conclusions: Oxygen consumption among critical COVID-19 patients varies by mode of delivery (invasive ventilation vs high-flow nasal cannula), across patients, and over treatment duration. Therefore, it is essential that health facilities routinely monitor oxygen utilization to better inform oxygen delivery system design and regular supply planning. Registration: ClinicalTrials.gov: CTG2021-01 ACTRN12620000421932.