Analysis and Research on Ventilation Strategy of the Common Forms of Windows Based on CFD Simulation

Based on the common forms of window opening in board hotels, PHOENICS software and CFD technology were used to simulate a variety of indoor wind environment. The open area, height of window sill, window form, position and shape of the window were varied for the simulation. The freshness of the air, relative to the appropriate wind speed, and the number of ventilation in the bathroom were adopted to evaluate the strategy analysis of the ventilation from different forms of windows. Suggestion strategy was given according to different needs for specific window.

Effects of individualized positive end-expiratory pressure combined with recruitment maneuver on intraoperative ventilation during abdominal surgery: a systematic review and network meta-analysis of randomized controlled trials

Low tidal volume ventilation strategy may lead to atelectasis without proper positive end-expiratory pressure (PEEP) and recruitment maneuver (RM) settings. RM followed by individualized PEEP was a new method to optimize the intraoperative pulmonary function. We conducted a systematic review and network meta-analysis of randomized clinical trials to compare the effects of individualized PEEP + RM on intraoperative pulmonary function and hemodynamic with other PEEP and RM settings. The primary outcomes were intraoperative oxygenation index and dynamic compliance, while the secondary outcomes were intraoperative heart rate and mean arterial pressure. In total, we identified 15 clinical trials containing 36 randomized groups with 3634 participants. Ventilation strategies were divided into eight groups by four PEEP (L: low, M: moderate, H: high, and I: individualized) and two RM (yes or no) settings. The main results showed that IPEEP + RM group was superior to all other groups regarding to both oxygenation index and dynamic compliance. LPEEP group was inferior to LPEEP + RM, MPEEP, MPEEP + RM, and IPEEP + RM in terms of oxygenation index and LPEEP + RM, MPEEP, MPEEP + RM, HPEEP + RM, IPEEP, and IPEEP + RM in terms of dynamic compliance. All comparisons were similar for secondary outcomes. Our analysis suggested that individualized PEEP and RM may be the optimal low tidal volume ventilation strategy at present, while low PEEP without RM is not suggested.

Mechanical Ventilation. Total Eclipse of the Heart (Editorial)

Results from recent large randomized trials investigating the use of high PEEP in patients without ARDS all evidence that high levels may increase mortality due to hypotension and bradycardia. A careful assessment of cardiac function – with particular focus on the right ventricle – should be performed before planning our ventilation strategy in any setting, including COVID-19 and ARDS in general. Mechanical ventilation should be respectful in regards of heart function, and tolerant with moderate hypoxia and hypercapnia, noninvasive (as soon as possible) and synchronized.