Matthieu Conseil

Sepsis is associated with a preferential diaphragmatic atrophy: a critically ill patient study using tridimensional computed tomography.

Background: Diaphragm and psoas are affected during sepsis in animal models. Whether diaphragm or limb muscle is preferentially affected during sepsis in the critically ill remains unclear. Methods: Retrospective secondary analysis study including 40 patients, comparing control (n = 17) and critically ill patients, with (n = 14) or without sepsis (n = 9). Diaphragm volume, psoas volume, and cross-sectional area of the skeletal muscles at the third lumbar vertebra were measured during intensive care unit (ICU) stay using tridimensional computed tomography scan volumetry. Diaphragm strength was evaluated using magnetic phrenic nerve stimulation. The primary endpoint was the comparison between diaphragm and peripheral muscle volume kinetics during the ICU stay among critically ill patients, with or without sepsis. Results: Upon ICU admission, neither diaphragm nor psoas muscle volumes were significantly different between critically ill and control patients (163 ± 53 cm3 vs. 197 ± 82 cm3 for the diaphragm, P = 0.36, and 272 ± 116 cm3 vs. to 329 ± 166 cm3 for the psoas, P = 0.31). Twenty-five (15 to 36) days after admission, diaphragm volume decreased by 11 ± 13% in nonseptic and by 27 ± 12% in septic patients, P = 0.01. Psoas volume decreased by 11 ± 10% in nonseptic and by 19 ± 13% in septic patients, P = 0.09. Upon ICU admission, diaphragm strength was correlated with diaphragm volume and was lower in septic (6.2 cm H2O [5.6 to 9.3]) than that in nonseptic patients (13.2 cm H2O [12.3 to 15.6]), P = 0.01. Conclusions: During the ICU stay, both diaphragm and psoas volumes decreased. In septic patients, the authors report for the first time in humans preferential diaphragm atrophy compared with peripheral muscles.

Prospective randomized crossover study of a new closed-loop control system versus pressure support during weaning from mechanical ventilation.

Background:Intellivent is a new full closed-loop controlled ventilation that automatically adjusts both ventilation and oxygenation parameters. The authors compared gas exchange and breathing pattern variability of Intellivent and pressure support ventilation (PSV). Methods:In a prospective, randomized, single-blind design crossover study, 14 patients were ventilated during the weaning phase, with Intellivent or PSV, for two periods of 24 h in a randomized order. Arterial blood gases were obtained after 1, 8, 16, and 24 h with each mode. Ventilatory parameters were recorded continuously in a breath-by-breath basis during the two study periods. The primary endpoint was oxygenation, estimated by the calculation of the difference between the PaO2/FIO2 ratio obtained after 24 h of ventilation and the PaO2/FIO2 ratio obtained at baseline in each mode. The variability in the ventilatory parameters was also evaluated by the coefficient of variation (SD to mean ratio). Results:There were no adverse events or safety issues requiring premature interruption of both modes. The PaO2/FIO2 (mean ± SD) ratio improved significantly from 245 ± 75 at baseline to 294 ± 123 (P = 0.03) after 24 h of Intellivent. The coefficient of variation of inspiratory pressure and positive end-expiratory pressure (median [interquartile range]) were significantly higher with Intellivent, 16 [11–21] and 15 [7–23]%, compared with 6 [5–7] and 7 [5–10]% in PSV. Inspiratory pressure, positive end-expiratory pressure, and FIO2 changes were adjusted significantly more often with Intellivent compared with PSV. Conclusions:Compared with PSV, Intellivent during a 24-h period improved the PaO2/FIO2 ratio in parallel with more variability in the ventilatory support and more changes in ventilation settings.

Comparative evaluation of three interfaces for non-invasive ventilation: a randomized cross-over design physiologic study on healthy volunteers

IntroductionInterface choice is crucial for non-invasive ventilation (NIV) success. We compared a new interface, the helmet next (HN), with the facial mask (FM) and the standard helmet (HS) in twelve healthy volunteers.MethodsIn this study, five NIV trials were randomly applied, preceded and followed by a trial of unassisted spontaneous breathing (SB). Baseline settings, for example, 5 cmH2O of both inspiratory pressure support (PS) and positive end-expiratory pressure (PEEP), were applied through FM, HS and HN, while increased settings (PS and PEEP of 8 cmH2O) were only applied through HS and HN. We measured flow, airway, esophageal and gastric pressures, and calculated inspiratory effort indexes and trigger delays. Comfort was assessed with a visual-analog-scale.ResultsWe found that FM, HS and HN at baseline settings were not significantly different with respect to inspiratory effort indexes and comfort. Inspiratory trigger delay and time of synchrony (TI,synchrony) were significantly improved by FM compared to both helmets, whereas expiratory trigger delay was shorter with FM, as opposed to HS only. HN at increased settings performed better than FM in decreasing inspiratory effort measured by pressure-time product of transdiaphragmatic pressure (PTPdi)/breath (10.7 ± 9.9 versus 17.0 ± 11.0 cmH2O*s), and PTPdi/min (128 ± 96 versus 204 ± 81 cmH2O*s/min), and PTPdi/L (12.6 ± 9.9 versus 30.2 ± 16.8 cmH2O*s/L). TI, synchrony was inferior between HN and HS at increased settings and FM.ConclusionsHN might hold some advantages with respect to interaction and synchrony between subject and ventilator, but studies on patients are needed to confirm these findings.Trial registrationClinicalTrials.gov NCT01610960

Differential Perceptions of Noninvasive Ventilation in Intensive Care among Medical Caregivers, Patients, and Their Relatives: A Multicenter Prospective Study—the Parvenir Study

Background:Noninvasive ventilation (NIV) requires a close “partnership” between a conscious patient and the patient’s caregivers. Specific perceptions of NIV stakeholders and their impact have been poorly described to date. The objectives of this study were to compare the perceptions of NIV by intensive care unit (ICU) physicians, nurses, patients, and their relatives and to explore factors associated with caregivers’ willingness to administer NIV and patients’ and relatives’ anxiety in relation to NIV. Methods:This is a prospective, multicenter questionnaire-based study. Results:Three hundred and eleven ICU physicians, 752 nurses, 396 patients, and 145 relatives from 32 ICUs answered the questionnaire. Nurses generally reported more negative feelings and more frequent regrets about providing NIV (median score, 3; interquartile range, [1 to 5] vs. 1 [1 to 5]; P < 0.0001) compared to ICU physicians. Sixty-four percent of ICU physicians and only 32% of nurses reported a high level of willingness to administer NIV, which was independently associated with NIV case-volume and workload. A high NIV session–related level of anxiety was observed in 37% of patients and 45% of relatives. “Dyspnea during NIV,” “long NIV session,” and “the need to have someone at the bedside” were identified as independent risk factors of high anxiety in patients. Conclusions:Lack of willingness of caregivers to administer NIV and a high level of anxiety of patients and relatives in relation to NIV are frequent in the ICU. Most factors associated with low willingness to administer NIV by nurses or anxiety in patients and relatives may be amenable to change. Interventional studies are now warranted to evaluate how to reduce these risk factors and therefore contribute to better management of a potentially traumatic experience. (Anesthesiology 2016; 124:1347-59)