Daily Ards Research Analysis

Introduction: The understanding of the interaction of closed-loop control of ventilation and oxygenation, specifically fraction of inspired oxygen (FiO 2 ) and positive end-expiratory pressure (PEEP), and fluid resuscitation after burn injury and acute lung injury from smoke inhalation is limited. We compared the effectiveness of FiO 2 , PEEP, and ventilation adjusted automatically using adaptive support ventilation (ASV) and decision support fluid resuscitation based on urine output in a clinically relevant conscious ovine model of lung injury secondary to combined smoke inhalation and major burn injury. Methods: Sheep were subjected to burn and smoke inhalation injury under deep anesthesia and analgesia. After injury, sheep were randomly allocated to two groups. 1) Closed-loop group: automated mechanical ventilation (ASV), oxygen FiO 2 and PEEP (n = 9); and 2) control group: mechanically ventilated with standard ASV mode (n = 8). FiO 2 , PEEP, and the percentage of the minute volume (%MV) were automatically adjusted in group 1, whereas PEEP was held at 5 cmH 2 O, and FiO 2 and %MV were manually adjusted in group 2. Decision support fluid resuscitation was guided based on urine output. Cardiopulmonary hemodynamics were monitored for 48 h. Results: There were no differences in body weight and the severity of smoke injury between the two groups. The closed-loop group resulted in significantly higher PEEP, %MV, static lung compliance, and survival rate; the driving pressure was significantly lower compared to the control group. In the closed-loop group, the net fluid balance at 48 h was significantly greater than in the control group. Conclusion: Closed-loop ventilation and oxygenation with decision support fluid resuscitation improve lung mechanics and survival in sheep with combined burn and smoke inhalation. There were no negative interactions observed between automated PEEP control and fluid management.

Epidemiology, ventilator management, and outcomes in patients with acute respiratory distress syndrome (ARDS) because of coronavirus disease 2019 (COVID-19) have been described extensively but have never been compared between countries. We performed an individual patient data analysis of four observational studies to compare epidemiology, ventilator management, and outcomes. We used propensity score weighting to control for confounding factors. The analysis included 6,702 patients: 1,500 from Argentina, 844 from Brazil, 975 from the Netherlands, and 3,383 from Spain. There were substantial differences in baseline characteristics between countries. There were small differences in ventilation management. Intensive care unit mortality was higher in Argentina and Brazil compared with the Netherlands and Spain (59.6% and 56.6% versus 32.1% and 34.7%; P <0.001). The median number of days free from ventilation and alive at day 28 was equally low (0 [0-7], 0 [0-18], 1 [0-16], and 0 [0-16] days, respectively; P = 0.03), and the median number of days free from ventilation and alive at day 60 was higher in the Netherlands and Spain (0 [0-37], 0 [0-50], 33 [0-48], and 26 [0-48] days, respectively; P <0.001). Propensity score matching confirmed the outcome differences. Thus, the outcome of COVID-19 ARDS patients in Argentina and Brazil was substantially worse compared with that of patients in the Netherlands and Spain. It is unlikely that this results from differences in case mix or ventilation management.

INTRODUCTION: Nasal synchronized intermittent positive pressure ventilation (nSIPPV) is an effective non-invasive ventilation technique, especially for preterm infants. Patient-ventilator synchrony is essential for providing effective respiratory support; however, no automated system is currently available for monitoring this parameter. A new tool for automatic assessment of patient-ventilator synchrony, the SyncNIV system, was developed and applied in this pilot study to evaluate differences between nSIPPV and non-synchronized nasal intermittent positive pressure ventilation (nIPPV) in preterm infants with respiratory distress. METHODS: This study involved designing a custom algorithm for signal analysis. Data were collected through a polygraph that could simultaneously gather respiratory data from the patients and the ventilator. Patient-ventilator synchrony was evaluated by applying the SyncNIV system in a randomized crossover study designed to compare nSIPPV and nIPPV. The primary outcome was the mean instant Synchrony Index (i-SI), defined as the portion of the inspiration effort sustained by ventilator inflation, expressed as a percentage. RESULTS: Fourteen infants with a median (IQR) gestational age of 28.6 (25.6-30.3) were enrolled. We analyzed 43,304 ventilator inflations and 50,221 patient breaths. The i-SI was 54.69% (44.49-60.09) in nSIPPV and 39.54% (33.40-48.75) in nIPPV, p < 0.05. CONCLUSION: The SyncNIV system confirmed better i-SI during nSIPPV than during nIPPV, demonstrating its effectiveness in assessing the differences between these two modes of non-invasive ventilation in preterm infants. The SyncNIV system could be a useful tool for optimizing the ventilation parameters and improving the effectiveness and comfort of respiratory support systems.