Sevoflurane in combination with esketamine is an effective sedation regimen in COVID-19 patients enabling assisted spontaneous breathing even during prone positioning.

BACKGROUND: Effective analgosedation for control of dyspnoea and for toleration of prone positioning (PP) in severe coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS) is difficult to adjust. This study was designed to evaluate the feasibility and safety of sedation with inhaled sevoflurane in combination with intravenous esketamine during PP in patients with COVID-19-ARDS (CARDS). METHODS: All mechanically ventilated COVID-19 patients admitted to the departmental intensive care unit from March to June 2020 were included in this epidemiological cohort study. Patients were sedated with inhaled sevoflurane in combination with eske-tamine during PP and not or only lightly sedated during the supine position. Assisted spontaneous breathing was applied in both prone and supine position. RESULTS: Adverse events were documented prospectively, and routine ventilation parameters, hemodynamic parameters, Richmond Agitation and Sedation Scale (RASS) and sevoflurane consumption were monitored. Altogether, 146 episodes of PP in 15 patients were observed. No severe sedation-related event was observed during 2610 hours of PP. In 2498 hours (96%) patients were successfully converted to a pressure-supported spontaneous breathing mode. CONCLUSIONS: Inhaled sedation with the AnaConDa-S-System (Sedana Medical AB, Danderyd, Sweden) alone is insufficient as soon as minute volume exceeds 7-8 L min-1, most likely due to technical reasons. Inhaled sedation with sevoflurane in combination with esketamine, however, safely enables prolonged prone positioning in patients with CARDS. Moreover, sedation depth was light enough to enable assisted spontaneous breathing during prone positioning.

Factors Associated With Spontaneous Awakening Trial and Spontaneous Breathing Trial Performance in Adults With Critical Illness: Analysis of a Multicenter, Nationwide, Cohort Study.

BACKGROUND: Broad-scale adoption of spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs) into everyday practice has been slow, and uncertainty exists regarding what factors facilitate or impede their routine delivery. RESEARCH QUESTION: What patient, practice, and pharmacologic factors are associated with SAT and SBT performance and to what extent do they predict overall SAT/SBT performance? STUDY DESIGN AND METHODS: This secondary analysis used data collected from a national quality improvement collaborative composed of 68 diverse ICUs. Adults with critical illness adults who received mechanical ventilation and/or continuously infused sedative medications were included. We performed mixed-effects logistic regression modeling, created receiver operating characteristic curves, and calculated the area under the curve (AUC). RESULTS: Included in the SAT and SBT analysis were 4,847 and 4,938 patients, respectively. In multivariable models controlling for admitting patient characteristics, factors independently associated with higher odds of a next-day SAT and SBT included physical restraint use (adjusted odds ratio [AOR], 1.63; 95% CI, 1.42-1.87; AOR, 1.83; 95% CI, 1.60-2.09), documented target sedation level (AOR, 1.68; 95% CI, 1.41-2.01; AOR, 1.46; 95% CI, 1.24-1.72), more frequent level of arousal assessments (AOR, 1.22; 95% CI, 1.03-1.43; AOR, 1.32; 95% CI, 1.13-1.54), and dexmedetomidine administration (AOR, 1.23; 95% CI, 1.05-1.45; AOR, 1.52; 95% CI, 1.27-1.80). Factors independently associated with lower odds of a next-day SAT and SBT included deep sedation/coma (AOR, 0.69; 95% CI, 0.60-0.80; AOR, 0.33; 95% CI, 0.28-0.37) and benzodiazepine (AOR, 0.83; 95% CI, 0.72-0.95; AOR, 0.67; 95% CI, 0.59-0.77) or ketamine (AOR, 0.34; 95% CI, 0.16-0.71; AOR, 0.40; 95% CI, 0.18-0.88) administration. Models incorporating admitting, daily, and unit variations displayed moderate discriminant accuracy in predicting next-day SAT (AUC, 0.73) and SBT (AUC, 0.72) performance. INTERPRETATION: There are a number of modifiable factors associated with SAT/SBT performance that are amenable to the development and testing of implementation interventions.

Comparison of Geometrical Lung Models to Calculate Tidal Volumes during Spontaneous Breathing

Demographic changes, increasing air pollution and the ongoing Covid-19 pandemic, causing virus-induced respiratory failures, monitoring of respiratory parameters is the focus of international interest. In this study, motioncapture- system data was used to get circumferences of the human thorax while executing different breathing patterns. Four geometric models were used to model tidal volumes of the tracked person while using spirometry data as a reference. The results show that all four introduced models can be used for tidal volume calculation based on changes in the thoracic circumference. In terms of accuracy, the use-case must be considered © 2021 by Walter de Gruyter Berlin/Boston.

High-Dose Nitric Oxide From Pressurized Cylinders and Nitric Oxide Produced by an Electric Generator From Air.

BACKGROUND: High-dose (≥ 80 ppm) inhaled nitric oxide (INO) has antimicrobial effects. We designed a trial to test the preventive effects of high-dose NO on coronavirus disease 2019 (COVID-19) in health care providers working with patients with COVID-19. The study was interrupted prematurely due to the introduction of COVID-19 vaccines for health care professionals. We thereby present data on safety and feasibility of breathing 160 ppm NO using 2 different NO sources, namely pressurized nitrogen/NO cylinders (INO) and electric NO (eNO) generators. METHODS: NO gas was inhaled at 160 ppm in air for 15 min twice daily, before and after each work shift, over 14 d by health care providers (NCT04312243). During NO administration, vital signs were continuously monitored. Safety was assessed by measuring transcutaneous methemoglobinemia (SpMet) and the inhaled nitrogen dioxide (NO2) concentration. RESULTS: Twelve healthy health care professionals received a collective total of 185 administrations of high-dose NO (160 ppm) for 15 min twice daily. One-hundred and seventy-one doses were delivered by INO and 14 doses by eNO. During NO administration, SpMet increased similarly in both groups (P = .82). Methemoglobin decreased in all subjects at 5 min after discontinuing NO administration. Inhaled NO2 concentrations remained between 0.70 ppm (0.63-0.79) and 0.75 ppm (0.67-0.83) in the INO group and between 0.74 ppm (0.68-0.78) and 0.88 ppm (0.70-0.93) in the eNO group. During NO administration, peripheral oxygen saturation and heart rate did not change. No adverse events occurred. CONCLUSIONS: This pilot study testing high-dose INO (160 ppm) for 15 min twice daily using eNO seems feasible and similarly safe when compared with INO.

Noninvasive respiratory support and patient self-inflicted lung injury in COVID-19: a narrative review.

COVID-19 pneumonia is associated with hypoxaemic respiratory failure, ranging from mild to severe. Because of the worldwide shortage of ICU beds, a relatively high number of patients with respiratory failure are receiving prolonged noninvasive respiratory support, even when their clinical status would have required invasive mechanical ventilation. There are few experimental and clinical data reporting that vigorous breathing effort during spontaneous ventilation can worsen lung injury and cause a phenomenon that has been termed patient self-inflicted lung injury (P-SILI). The aim of this narrative review is to provide an overview of P-SILI pathophysiology and the role of noninvasive respiratory support in COVID-19 pneumonia. Respiratory mechanics, vascular compromise, viscoelastic properties, lung inhomogeneity, work of breathing, and oesophageal pressure swings are discussed. The concept of P-SILI has been widely investigated in recent years, but controversies persist regarding its mechanisms. To minimise the risk of P-SILI, intensivists should better understand its underlying pathophysiology to optimise the type of noninvasive respiratory support provided to patients with COVID-19 pneumonia, and decide on the optimal timing of intubation for these patients.

Spontaneous Breathing and Evolving Phenotypes of Lung Damage in Patients with COVID-19: Review of Current Evidence and Forecast of a New Scenario.

The mechanisms of acute respiratory failure other than inflammation and complicating the SARS-CoV-2 infection are still far from being fully understood, thus challenging the management of COVID-19 patients in the critical care setting. In this unforeseen scenario, the role of an individual's excessive spontaneous breathing may acquire critical importance, being one potential and important driver of lung injury and disease progression. The consequences of this acute lung damage may impair lung structure, forecasting the model of a fragile respiratory system. This perspective article aims to analyze the progression of injured lung phenotypes across the SARS-CoV-2 induced respiratory failure, pointing out the role of spontaneous breathing and also tackling the specific respiratory/ventilatory strategy required by the fragile lung type.

Prone Positioning in Spontaneously Breathing Subjects With Moderate or Severe ARDS During Invasive Ventilation.

BACKGROUND: Prone positioning (PP) during invasive mechanical ventilation improves outcomes of patients with severe ARDS. Recent studies suggest that PP in spontaneously breathing, nonintubated patients with acute respiratory failure is well tolerated and improves oxygenation. However, little is known regarding patient triggered ventilation in intubated patients with ARDS undergoing PP. We conducted a retrospective review of our experience with placing patients in the prone position in 2 cohorts of subjects with moderate and severe ARDS (ie, one cohort with ARDS related to COVID-19, the other with ARDS unrelated to COVID-19), many of whom were receiving pressure support ventilation (PSV). METHODS: We conducted a retrospective analysis in a single 22-bed mixed ICU. The subjects included in the analysis were ≥ 18 y old, met the Berlin definition for moderate or severe ARDS (whether related COVID-19 or not), and underwent PP during invasive ventilation. RESULTS: 39 subjects were included in the analysis: 20 subjects had ARDS related to COVID-19, while 19 had ARDS related to other etiologies. A total of 113 PP episodes were analyzed: 84 during PSV and 29 during volume control continuous mandatory ventilation. PP during PSV was well tolerated and was effective in improving arterial oxygenation (ie, an increase of median [Formula: see text] from 100 mm Hg [interquartile range 75-120] before PP to 135 mm Hg [interquartile range 111-161] at the end of the PP session, P < .0001). No significant difference between continuous mandatory ventilation and PSV was noted regarding arterial oxygenation during PP. Compared with continuous mandatory ventilation mode, PP during PSV was associated with a significant decrease in the use of neuromuscular blocking agents (4% vs 69% of subjects, P < .001), while sedative requirements remained unchanged. CONCLUSIONS: In a retrospective analysis of consecutive intubated subjects with moderate or severe ARDS, related or not to COVID-19, spontaneous breathing during PP was well tolerated and achieved significant improvement in arterial oxygenation.