In COVID-19 acute hypoxemic respiratory failure, awake prone positioning vs. the supine position reduces intubations.

SOURCE CITATION: Li J, Luo J, Pavlov I, et al. Awake prone positioning for non-intubated patients with COVID-19-related acute hypoxaemic respiratory failure: a systematic review and meta-analysis. Lancet Respir Med. 2022;10:573-83. 35305308.

Prone Chest Radiographs: Distinguishing Features and Identification of Support Devices.

PURPOSE: Prone position is known to improve acute lung injury, and chest radiographs are often necessary to monitor disease and confirm support device placement. However, there is a paucity of literature regarding radiographs obtained in this position. We evaluated prone radiographs for distinguishing features and ability to identify support devices. METHODS: Pairs of prone and supine radiographs obtained during the COVID-19 pandemic were assessed retrospectively. IRB approval and waiver of informed consent were obtained. Radiographs were assessed for imaging adequacy, distinguishing features, and support device identification (endotracheal tube, enteric tube, or central line). Radiographs were reviewed by ≥ 2 cardiothoracic radiologists. RESULTS: Radiographs from 81 patients (63yo ± 13, 30% women) were reviewed. Prone and supine radiographs were comparable for imaging the lung bases (81% vs. 90%, p = 0.35) and apices (93% vs. 94%, p = 1); prone radiographs more frequently had significant rotation (36% vs. 19%, p = 0.021). To identify prone technique, scapula tip located beyond the rib border was 89% sensitive (95%CI 80-95%) and 85% specific (76-92%), and a fundal stomach bubble was 44% sensitive (33-56%) and 90% specific (81-96%). For women, displaced breast shadow was 46% sensitive (26-67%) and 92% specific (73-99%). Prone and supine radiographs each identified > 99% of support devices. Prone exams trended toward increased rate of malpositioned device (12% vs. 6%, p = 0.07). CONCLUSION: Scapula position reliably distinguishes prone from supine position; fundal stomach bubble or displaced breast shadow is specific for prone position. Prone radiographs reliably identify line and tube position, which is particularly important as prone patients appear at increased risk for malpositioned devices.

Extended prone positioning duration for COVID-19-related ARDS: benefits and detriments.

BACKGROUND: During the COVID-19 pandemic, many more patients were turned prone than before, resulting in a considerable increase in workload. Whether extending duration of prone position may be beneficial has received little attention. We report here benefits and detriments of a strategy of extended prone positioning duration for COVID-19-related acute respiratory distress syndrome (ARDS). METHODS: A eetrospective, monocentric, study was performed on intensive care unit patients with COVID-19-related ARDS who required tracheal intubation and who have been treated with at least one session of prone position of duration greater or equal to 24 h. When prone positioning sessions were initiated, patients were kept prone for a period that covered two nights. Data regarding the incidence of pressure injury and ventilation parameters were collected retrospectively on medical and nurse files of charts. The primary outcome was the occurrence of pressure injury of stage ≥ II during the ICU stay. RESULTS: For the 81 patients included, the median duration of prone positioning sessions was 39 h [interquartile range (IQR) 34-42]. The cumulated incidence of stage ≥ II pressure injuries was 26% [95% CI 17-37] and 2.5% [95% CI 0.3-8.8] for stages III/IV pressure injuries. Patients were submitted to a median of 2 sessions [IQR 1-4] and for 213 (94%) prone positioning sessions, patients were turned over to supine position during daytime, i.e., between 9 AM and 6 PM. This increased duration was associated with additional increase in oxygenation after 16 h with the PaO2/FiO2 ratio increasing from 150 mmHg [IQR 121-196] at H+ 16 to 162 mmHg [IQR 124-221] before being turned back to supine (p = 0.017). CONCLUSION: In patients with extended duration of prone position up to 39 h, cumulative incidence for stage ≥ II pressure injuries was 26%, with 25%, 2.5%, and 0% for stage II, III, and IV, respectively. Oxygenation continued to increase significantly beyond the standard 16-h duration. Our results may have significant impact on intensive care unit staffing and patients' respiratory conditions. TRIAL REGISTRATION: Institutional review board 00006477 of HUPNVS, Université Paris Cité, APHP, with the reference: CER-2021-102, obtained on October 11th 2021. Registered at Clinicaltrials (NCT05124197).

Effect of body position on the redistribution of regional lung aeration during invasive and non-invasive ventilation of COVID-19 patients.

Severe COVID-19-related acute respiratory distress syndrome (C-ARDS) requires mechanical ventilation. While this intervention is often performed in the prone position to improve oxygenation, the underlying mechanisms responsible for the improvement in respiratory function during invasive ventilation and awake prone positioning in C-ARDS have not yet been elucidated. In this prospective observational trial, we evaluated the respiratory function of C-ARDS patients while in the supine and prone positions during invasive (n = 13) or non-invasive ventilation (n = 15). The primary endpoint was the positional change in lung regional aeration, assessed with electrical impedance tomography. Secondary endpoints included parameters of ventilation and oxygenation, volumetric capnography, respiratory system mechanics and intrapulmonary shunt fraction. In comparison to the supine position, the prone position significantly increased ventilation distribution in dorsal lung zones for patients under invasive ventilation (53.3 ± 18.3% vs. 43.8 ± 12.3%, percentage of dorsal lung aeration ± standard deviation in prone and supine positions, respectively; p = 0.014); whereas, regional aeration in both positions did not change during non-invasive ventilation (36.4 ± 11.4% vs. 33.7 ± 10.1%; p = 0.43). Prone positioning significantly improved the oxygenation both during invasive and non-invasive ventilation. For invasively ventilated patients reduced intrapulmonary shunt fraction, ventilation dead space and respiratory resistance were observed in the prone position. Oxygenation is improved during non-invasive and invasive ventilation with prone positioning in patients with C-ARDS. Different mechanisms may underly this benefit during these two ventilation modalities, driven by improved distribution of lung regional aeration, intrapulmonary shunt fraction and ventilation-perfusion matching. However, the differences in the severity of C-ARDS may have biased the sensitivity of electrical impedance tomography when comparing positional changes between the protocol groups.Trial registration: ClinicalTrials.gov (NCT04359407) and Registered 24 April 2020, https://clinicaltrials.gov/ct2/show/NCT04359407 .

The effectiveness of the Safety in Interventional Radiology (SIR) Shield in reducing droplet transmission and its effect on image quality and radiation dose.

OBJECTIVE: To evaluate the efficacy of a barrier shield in reducing droplet transmission and its effect on image quality and radiation dose in an interventional suite. METHODS: A human cough droplet visualisation model in a supine position was developed to assess efficacy of barrier shield in reducing environmental contamination. Its effect on image quality (resolution and contrast) was evaluated via image quality test phantom. Changes in the radiation dose to patient post-shield utilisation was measured. RESULTS: Use of the shield prevented escape of visible fluorescent cough droplets from the containment area. No subjective change in line-pair resolution was observed. No significant difference in contrast-to-noise ratio was measured. Radiation dosage to patient was increased; this is predominantly attributed to the increased air gap and not the physical properties of the shield. CONCLUSION: Use of the barrier shield provided an effective added layer of personal protection in the interventional radiology theatre for aerosol generating procedures. ADVANCES IN KNOWLEDGE: This is the first time a human supine cough droplet visualisation has been developed. While multiple types of barrier shields have been described, this is the first systematic practical evaluation of a barrier shield designed for use in the interventional radiology theatre.

Effect of prone versus supine position in COVID-19 patients: A systematic review and meta-analysis.

STUDY OBJECTIVE: To review the effects of prone position and supine position on oxygenation parameters in patients with Coronavirus Disease 2019 (COVID-19). DESIGN: Systematic review and meta-analysis of non-randomized trials. PATIENTS: Databases of EMBASE, MEDLINE and CENTRAL were systematically searched from its inception until March 2021. INTERVENTIONS: COVID-19 patients being positioned in the prone position either whilst awake or mechanically ventilated. MEASUREMENTS: Primary outcomes were oxygenation parameters (PaO2/FiO2 ratio, PaCO2, SpO2). Secondary outcomes included the rate of intubation and mortality rate. RESULTS: Thirty-five studies (n = 1712 patients) were included in this review. In comparison to the supine group, prone position significantly improved the PaO2/FiO2 ratio (study = 13, patients = 1002, Mean difference, MD 52.15, 95% CI 37.08 to 67.22; p < 0.00001) and SpO2 (study = 11, patients = 998, MD 4.17, 95% CI 2.53 to 5.81; p ≤0.00001). Patients received prone position were associated with lower incidence of mortality (study = 5, patients = 688, Odd ratio, OR 0.44, 95% CI 0.24 to 0.80; p = 0.007). No significant difference was noted in the incidence of intubation rate (study = 5, patients = 626, OR 1.20, 95% CI 0.77 to 1.86; p = 0.42) between the supine and prone groups. CONCLUSION: Our meta-analysis demonstrated that prone position improved PaO2/FiO2 ratio with better SpO2 than supine position in COVID-19 patients. Given the limited number of studies with small sample size and substantial heterogeneity of measured outcomes, further studies are warranted to standardize the regime of prone position to improve the certainty of evidence. PROSPERO Registration: CRD42021234050.

Correlation of echocardiographic parameters in prone and supine positions in normal adults using a novel approach.

BACKGROUND: Transthoracic echocardiography (TTE) in prone position is challenging. Innovative use of transesophageal echocardiography (TEE) probe to perform TTE for such patients has been described; but reproducibility and correlation of the TTE measurements by this technique with those obtained by the standard supine TTE study are still unknown. METHODS: We enrolled 30 non-COVID-19 individuals, with a mean (SD) age 35 (10.9) years and 11 females, to study the agreement between the transthoracic measurements of the left ventricular (LV), left atrial (LA), aortic dimensions, and ejection fraction (EF) obtained in prone position using an external TEE probe versus the standard supine position using the conventional TTE probe. RESULTS: There were no significant differences between LV end-diastolic and end-systolic diameters, septal wall thickness, posterior wall thickness, and aortic root dimensions in the prone versus the supine positions, while the mean EF (60.3% vs 63.1%, P = .014) and mean LA dimensions (1.8 vs 1.9 cm/m2 , P < .001) were significantly lower in the prone position. The mean time of scans was significantly longer in the prone as compared to the supine position (12.5 vs 4.5 minutes, P < .001). All supine studies had good quality while in the prone position four studies were of poor quality, and one was nondiagnostic. CONCLUSIONS: Assessment of cardiac dimensions and systolic function in the prone position using transthoracic TEE probe was feasible. LV and aortic dimensions agreed well with the standard TTE in supine position; however, LA dimensions and EF were lower in the prone position.

Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients.

BACKGROUND: Limited data are available on the use of prone position in intubated, invasively ventilated patients with Coronavirus disease-19 (COVID-19). Aim of this study is to investigate the use and effect of prone position in this population during the first 2020 pandemic wave. METHODS: Retrospective, multicentre, national cohort study conducted between February 24 and June 14, 2020, in 24 Italian Intensive Care Units (ICU) on adult patients needing invasive mechanical ventilation for respiratory failure caused by COVID-19. Clinical data were collected on the day of ICU admission. Information regarding the use of prone position was collected daily. Follow-up for patient outcomes was performed on July 15, 2020. The respiratory effects of the first prone position were studied in a subset of 78 patients. Patients were classified as Oxygen Responders if the PaO2/FiO2 ratio increased ≥ 20 mmHg during prone position and as Carbon Dioxide Responders if the ventilatory ratio was reduced during prone position. RESULTS: Of 1057 included patients, mild, moderate and severe ARDS was present in 15, 50 and 35% of patients, respectively, and had a resulting mortality of 25, 33 and 41%. Prone position was applied in 61% of the patients. Patients placed prone had a more severe disease and died significantly more (45% vs. 33%, p < 0.001). Overall, prone position induced a significant increase in PaO2/FiO2 ratio, while no change in respiratory system compliance or ventilatory ratio was observed. Seventy-eight % of the subset of 78 patients were Oxygen Responders. Non-Responders had a more severe respiratory failure and died more often in the ICU (65% vs. 38%, p = 0.047). Forty-seven % of patients were defined as Carbon Dioxide Responders. These patients were older and had more comorbidities; however, no difference in terms of ICU mortality was observed (51% vs. 37%, p = 0.189 for Carbon Dioxide Responders and Non-Responders, respectively). CONCLUSIONS: During the COVID-19 pandemic, prone position has been widely adopted to treat mechanically ventilated patients with respiratory failure. The majority of patients improved their oxygenation during prone position, most likely due to a better ventilation perfusion matching. TRIAL REGISTRATION: clinicaltrials.gov number: NCT04388670.

Epidemic Time: Thinking from the Sickbed.

To experience an epidemic while lying on a sickbed opens up other ways of thinking through time, epidemics, and sequence from those developed by Charles Rosenberg in his 1989 essay, "What Is an Epidemic?". In this essay, a patient recovering from COVID-19 analyzes how histories of epidemics often follow the logic proposed by the discipline of epidemiology itself: a focus on acute cases and on a tracking of the "peak(s)" often means that longer temporalities of suffering are hidden. In contrast, this essay follows "Long Covid"-an illness collectively made and named by patients, which changed how the natural history of a new disease (COVID-19) was being mapped out by conventional scientific experts. Long Covid conceptualizes time differently from common categories and prefixes used in medicine and epidemiology, such as the "chronic" or the "post-." The collective labor of ill people thinking from the sickbed-both those with Long Covid and those working to bring to visibility other illnesses and the sequelae of other epidemics-has allowed other possible arrangements of sick bodies, symptoms, and diagnostic classifications to come into view. These arrangements hold potential for historians of medicine, as well as for clinical scientists.

Value of renal resistive index in covid-19 ARDS patients: an early inflammation alert for the lung-kidney cross-talk?

We analysed RRI and other hemodynamic, re-spiratory and inflammation parameters in critically ill pa-tients affected by severe covid-19 with acute distress respi-ratory syndrome (ARDS) aiming at verifying their modifica-tions during supine and prone positioning and any mutual correlation or interplay with RRI.

Abordaje hemodinámico y ventilatorio en pacientes con COVID-19.

The severe acute respiratory syndrome (SARS-Cov-2) is a clinical entity generated by this new virus a Coronavirus (COVID-19). Disease called COVID-19 (CoronaVIrus Disease 2019) by the World Health Organization. Its presentation is acute respiratory failure characterized by hyperinflation of the lung that leads to an increase in capillaries and epithelial permeability, with loss of ventilation of lung tissue and increases lung stiffness. These disturbances lead to imbalances between ventilation and perfusion ratio, which ultimately result in hypoxemia and impaired carbon dioxide clearance. For this review, a search of PubMed and Trip Database was performed. Due to the scarcity of publications, a specific search algorithm was not used. The objective is to review, the evidence and the recommendations of national and international experts, of the hemodynamic and ventilatory management of these patients.

El coronavirus del síndrome respiratorio agudo grave 2 (SARS-CoV-2, conocido previamente como nCoV-2019) es el agente causal de una nueva enfermedad denominada COVID-19 (COronaVIrus Disease 2019) por la Organización Mundial de la Salud. Su presentación es la insuficiencia respiratoria aguda caracterizada por una hiperinflación del pulmón que conduce a un incremento de los capilares y permeabilidad epitelial, con pérdida de la aireación de tejido pulmonar e incremento de la rigidez pulmonar. Estas alteraciones conducen a desequilibrios entre la ventilación y la relación de perfusión, que finalmente resultan en hipoxemia y deterioro de la depuración de dióxido de carbono. Para la presente revisión se realizó una búsqueda en PubMed y Trip Database. Debido a la escasez de publicaciones no se utilizó un algoritmo de búsqueda específico. El objetivo es dar a conocer, de acuerdo con la evidencia y las recomendaciones de expertos nacionales e internacionales, el manejo hemodinámico y ventilatorio de estos pacientes.

A novel, automated, quantification of abnormal lung parenchyma in patients with COVID-19 infection: Initial description of feasibility and association with clinical outcome.

OBJECTIVE: Ground-glass opacities are the most frequent radiologic features of COVID-19 patients. We aimed to determine the feasibility of automated lung volume measurements, including ground-glass volumes, on the CT of suspected COVID-19 patients. Our goal was to create an automated and quantitative measure of ground-glass opacities from lung CT images that could be used clinically for diagnosis, triage and research. DESIGN: Single centre, retrospective, observational study. MEASUREMENTS: Demographic data, respiratory support treatment (synthetised in the maximal respiratory severity score) and CT-images were collected. Volume of abnormal lung parenchyma was measured with conventional semi-automatic software and with a novel automated algorithm based on voxels X-Ray attenuation. We looked for the relationship between the automated and semi-automated evaluations. The association between the ground-glass opacities volume and the maximal respiratory severity score was assessed. MAIN RESULTS: Thirty-seven patients were included in the main outcome analysis. The mean duration of automated and semi-automated volume measurement process were 15 (2) and 93 (41) min, respectively (p=8.05*10-8). The intraclass correlation coefficient between the semi-automated and automated measurement of ground-glass opacities and restricted normally aerated lung were both superior to 0.99. The association between the automated measured lung volume and the maximal clinical severity score was statistically significant for the restricted normally aerated (p=0.0097, effect-size: -385mL) volumes and for the ratio of ground-glass opacities/restricted normally aerated volumes (p=0.027, effect-size: 3.3). CONCLUSION: The feasibility and preliminary validity of automated impaired lung volume measurements in a high-density COVID-19 cluster was confirmed by our results.

Effects of COVID-19 lockdown on heart rate variability.

INTRODUCTION: Strict lockdown rules were imposed to the French population from 17 March to 11 May 2020, which may result in limited possibilities of physical activity, modified psychological and health states. This report is focused on HRV parameters kinetics before, during and after this lockdown period. METHODS: 95 participants were included in this study (27 women, 68 men, 37 ± 11 years, 176 ± 8 cm, 71 ± 12 kg), who underwent regular orthostatic tests (a 5-minute supine followed by a 5-minute standing recording of heart rate (HR)) on a regular basis before (BSL), during (CFN) and after (RCV) the lockdown. HR, power in low- and high-frequency bands (LF, HF, respectively) and root mean square of the successive differences (RMSSD) were computed for each orthostatic test, and for each position. Subjective well-being was assessed on a 0-10 visual analogic scale (VAS). The participants were split in two groups, those who reported an improved well-being (WB+, increase >2 in VAS score) and those who did not (WB-) during CFN. RESULTS: Out of the 95 participants, 19 were classified WB+ and 76 WB-. There was an increase in HR and a decrease in RMSSD when measured supine in CFN and RCV, compared to BSL in WB-, whilst opposite results were found in WB+ (i.e. decrease in HR and increase in RMSSD in CFN and RCV; increase in LF and HF in RCV). When pooling data of the three phases, there were significant correlations between VAS and HR, RMSSD, HF, respectively, in the supine position; the higher the VAS score (i.e., subjective well-being), the higher the RMSSD and HF and the lower the HR. In standing position, HRV parameters were not modified during CFN but RMSSD was correlated to VAS. CONCLUSION: Our results suggest that the strict COVID-19 lockdown likely had opposite effects on French population as 20% of participants improved parasympathetic activation (RMSSD, HF) and rated positively this period, whilst 80% showed altered responses and deteriorated well-being. The changes in HRV parameters during and after the lockdown period were in line with subjective well-being responses. The observed recordings may reflect a large variety of responses (anxiety, anticipatory stress, change on physical activity…) beyond the scope of the present study. However, these results confirmed the usefulness of HRV as a non-invasive means for monitoring well-being and health in this population.