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OBJECTIVES The mechanisms of high-flow nasal cannula are still debated but may be mediated by the generation of low positive end-expiratory pressure and a washout of the airway dead space. The aims of this study were to assess the effects of high-flow nasal cannula on tidal volume using a noninvasive method using a time-of-flight camera, under various conditions. DESIGN A physiologic evaluation in healthy volunteers. SETTING An university hospital ICU. SUBJECTS Ten healthy volunteers were included in a physiologic study (CamOpt study, ClinicalTrials.gov identifier: NCT04096183). INTERVENTIONS All volunteers were submitted to 12 different conditions (i.e., gas flow [baseline = 0; 30-60 L/min]; mouth [open/closed]; respiratory rate [baseline; baseline + 10 breaths/min]). Tidal volume measurements were performed every minute, during a 6-minute recording period. In all combinations, reference respiratory rate was measured by using chronometric evaluation, over a 30-second period (RRREF), and by using the time-of-flight camera (RRTOF). MEASUREMENTS AND MAIN RESULTS Tidal volume increased while increasing gas flow whatever the respiratory rate and mouth condition (p < 0.001). Similar results were observed whatever the experimental conditions (p < 0.01), except one (baseline respiratory rate + 10 breaths/min and mouth closed). Tidal volume increased while decreasing respiratory rate (p < 0.001) and mouth closing (p < 0.05). Proportion of tidal volume greater than 10, 15, and 20 mL/kg changed while increasing the flow. RRTOF was in agreement with RRREF (intraclass correlation coefficient, 0.96), with a low mean bias (0.55 breaths/min) and acceptable deviation. CONCLUSIONS Time-of-flight enables to detect tidal volume changes under various conditions of high-flow nasal cannula application. Tidal volume increased significantly while increasing gas flow and mouth closing. Such technique might be useful to monitor the risk of patient self-inflicted lung injury or under assistance.

Tidal volume monitoring may help minimize lung injury during respiratory assistance. Surface imaging using time-of-flight camera is a new, non-invasive, non-contact, radiation-free, and easy-to-use technique that enables tidal volume and respiratory rate measurements. The objectives of the study were to determine the accuracy of Time-of-Flight volume (VTTOF) and respiratory rate (RRTOF) measurements at the bedside, and to validate its application for spontaneously breathing patients under high flow nasal canula. Data analysis was performed within the ReaSTOC data-warehousing project (ClinicalTrials.gov identifier NCT02893462). All data were recorded using standard monitoring devices, and the computerized medical file. Time-of-flight technique used a Kinect V2 (Microsoft, Redmond, WA, USA) to acquire the distance information, based on measuring the phase delay between the emitted light-wave and received backscattered signals. 44 patients (32 under mechanical ventilation; 12 under high-flow nasal canula) were recorded. High correlation (r = 0.84; p 8 mL/kg) and low ventilation in 6 patients (tidal volume

PURPOSE Monitoring of physiological parameters is a major concern in Intensive Care Units (ICU) given their role in the assessment of vital organ function. Within this context, one issue is the lack of efficient noncontact techniques for respiratory monitoring. In this paper, we present a novel noncontact solution for real-time respiratory monitoring and function assessment of ICU patients. METHODS The proposed system uses a Time-of-Flight depth sensor to analyze the patient's chest wall morphological changes in order to estimate multiple respiratory function parameters. The automatic detection of the patient's torso is also proposed using a deep neural network model trained on the COCO dataset. The evaluation of the proposed system was performed on a mannequin and on 16 mechanically ventilated patients (a total of 216 recordings) admitted in the ICU of the Brest University Hospital. RESULTS The estimation of respiratory parameters (respiratory rate and tidal volume) showed high correlation with the reference method (r = 0.99; P

Hypoxaemia and hyperoxaemia may occur after surgery, with related complications. This multicentre randomised trial evaluated the impact of automated closed-loop oxygen administration after high-risk abdominal or thoracic surgeries in terms of optimising the oxygen saturation measured by pulse oximetry time within target range.After extubation, patients with an intermediate to high risk of post-operative pulmonary complications were randomised to "standard" or "automated" closed-loop oxygen administration. The primary outcome was the percentage of time within the oxygenation range, during a 3-day frame. The secondary outcomes were the time with hypoxaemia and hyperoxaemia under oxygen.Among the 200 patients, time within range was higher in the automated group, both initially (≤3 h; 91.4±13.7%Automated closed-loop oxygen administration promotes greater time within the oxygenation target, as compared to standard manual administration, thus reducing the occurrence of hypoxaemia and hyperoxaemia.

IntroductionHypoxaemia and hyperoxaemia may occur after surgery, with related complications. This multicentre randomised trial evaluated the impact of automated closed-loop oxygen administration after high-risk abdominal or thoracic surgeries in terms of optimising the oxygen saturation measured by pulse oximetry time within target range.MethodsAfter extubation, patients with an intermediate to high risk of post-operative pulmonary complications were randomised to “standard” or “automated” closed-loop oxygen administration. The primary outcome was the percentage of time within the oxygenation range, during a 3-day frame. The secondary outcomes were the time with hypoxaemia and hyperoxaemia under oxygen.ResultsAmong the 200 patients, time within range was higher in the automated group, both initially (≤3 h; 91.4±13.7% versus 40.2±35.1% of time, difference +51.0% (95% CI −42.8–59.2%); pversus 62.1±23.3% of time, difference +31.9% (95% CI 26.3–37.4%); pversus 370.5±594.3 min (5.0±11.2%), difference −10.2% (95% CI −13.9–−6.6%); pversus 177.9±277.2 min (27.0±23.8%), difference −22.0% (95% CI −27.6–−16.4%); p10% of the entire monitoring time during the 3 days within the standard group, as compared to the automated group (pConclusionAutomated closed-loop oxygen administration promotes greater time within the oxygenation target, as compared to standard manual administration, thus reducing the occurrence of hypoxaemia and hyperoxaemia.

Background: Hypoxemia and hyperoxia may occur after surgery with related complications. Automated oxygen titration and weaning (FreeO2) may improve oxygenation and outcome. Aims and Objectives: To evaluate the impact of FreeO2 vs conventional O2 after surgeries at risk of desaturation, on the oxygenation parameters and patient’s outcome. Methods: This study is a prospective, multicenter, randomized, controlled, open trial. After thoracic or abdominal surgery, patients were randomly assigned to the manual O2 administration or automated O2 administration (FreeO2). Primary outcome was the percentage of time spent in the SpO2 target zone, during a 3-days time frame. Secondary outcomes were the nursing workload, the time spent with severe desaturation (SpO2 98%); the O2 consumption, the duration of O2 administration during hospitalization, the frequency of use of ventilation (invasive or noninvasive) the hospitalization length of stay and the survival rate. Results: 200 patients were enrolled and 180 randomized and analyzed. There was no significant difference in baseline characteristics. Oxygenation and primary outcome are presented in the table: Conclusion: Automated oxygen titration and weaning significantly improves oxygenation parameters, decrease both severe hypoxemia and severe hyperoxemia after major horacic or abdominal surgery.

BackgroundRespiratory rate is among the first vital signs to change in deteriorating patients. The aims of this study were to evaluate the accuracy of respiratory rate measurements using a specifically dedicated reflection-mode photoplethysmographic signal analysis in a pathological condition (PPG-RR) and to validate its implementation within medical devices.MethodsThis study is derived from a data mining project, including all consecutive patients admitted to our ICU (ReaSTOC study, ClinicalTrials.gov identifier: NCT02893462). During the evaluation phase of the algorithm, PPG-RR calculations were retrospectively performed on PPG waveforms extracted from the data warehouse and compared with RR reference values. During the prospective phase, PPG-RR calculations were automatically and continuously performed using a dedicated device (FreeO2, Oxynov, Québec, QC, Canada). In all phases, reference RR was measured continuously using electrical thoracic impedance and chronometric evaluation (Manual-RR) over a 30-s period.ResultsIn total, 201 ICU patients’ recordings (SAPS II 51.7 ± 34.6) were analysed during the retrospective evaluation phase, most of them being admitted for a respiratory failure and requiring invasive mechanical ventilation. PPG-RR determination was available in 95.5% cases, similar to reference (22 ± 4 vs. 22 ± 5 c/min, respectively;p = 1), and well correlated with reference values (R = 0.952;p r = 0.78;p ConclusionAccording to our results, PPG-RR is an interesting approach for ventilation monitoring, as this technique would make simultaneous monitoring of respiratory rate and arterial oxygen saturation possible, thus minimizing the number of sensors attached to the patient.Trial registry numberClinicalTrials.gov identifier NCT02893462

International audience; Scedosporium species are opportunistic pathogens responsible for a large variety of infections in humans. An increasing occurrence was observed in patients with underlying conditions such as immunosuppression or cystic fibrosis. Indeed, the genus Scedosporium ranks the second among the filamentous fungi colonizing the respiratory tracts of the CF patients. To date, there is very scarce information on the pathogenic mechanisms, at least in part because of the limited genetic tools available. In the present study, we successfully developed an efficient transformation and targeted gene disruption approach on the species Scedosporium aurantiacum. The disruption cassette was constructed using double-joint PCR procedure, and resistance to hygromycin B as the selection marker. This proof of concept was performed on the functional gene SODC encoding the Cu,Zn-superoxide dismutase. Disruption of the SODC gene improved susceptibility of the fungus to oxidative stress. This technical advance should open new research areas and help to better understand the biology of Scedosporium species.

IntroductionHypoxemia and hyperoxia may occur after surgery with potential related complications. The FreeO2PostOp trial is a prospective, multicentre, randomised controlled trial that evaluates the clinical impact of automated O2administration versus conventional O2therapy after major abdominal or thoracic surgeries. The study is powered to demonstrate benefits of automated oxygen titration and weaning in term of oxygenation, which is an important surrogate for complications after such interventions.Methods and analysisAfter extubation, patients are randomly assigned to theStandard(manual O2administration) orFreeO2group (automated closed-loop O2administration). Stratification is performed for the study centre and a medical history of chronic obstructive pulmonary disease (COPD). Primary outcome is the percentage of time spent in the target zone of oxygen saturation, during a 3-day time frame. In both groups, patients will benefit from continuous oximetry recordings. The target zone of oxygen saturation is SpO2=88%–92% for patients with COPD and 92%–96% for patients without COPD. Secondary outcomes are the nursing workload assessed by the number of manual O2flow adjustments, the time spent with severe desaturation (SpO22>98%), the time spent in a hyperoxia area (SpO2>98%), the VO2, the duration of oxygen administration during hospitalisation, the frequency of use of mechanical ventilation (invasive or non-invasive), the duration of the postrecovery room stay, the hospitalisation length of stay and the survival rate.Ethics and disseminationThe FreeO2PostOp study is conducted in accordance with the declaration of Helsinki and was registered on 11 September 2015 (http://www.clinicaltrials.gov). First patient inclusion was performed on 14 January 2016. The results of the study will be presented at academic conferences and submitted to peer-reviewed journals.Trial registration numberNCT02546830.