Rapid pressure compensation by automated cuff pressure controllers worsens sealing in tracheal tubes

Background Cyclic redistribution of air within the cuff during respiratory pressure changes creates a self-sealing mechanism which allows tracheal sealing, despite tracheal airway pressure being above baseline cuff inflation pressure. The aim of the present study was to investigate the effect of continuous automated cuff pressure regulation on tracheal sealing during cyclic respiratory pressure changes. Methods In vitro tracheal sealing was studied in four different high volume-low pressure (HVLP) tracheal tube cuffs size internal diameter 8.0 and 5.0 mm in combination with a conventional pressure manometer and two different automated pressure controllers (VBM Cuff Controller; Cuff Pressure Control Tracoe™). Experiments were performed at 10, 15, 20, and 25 cm H2O cuff pressure during intermittent positive pressure ventilation with peak inspiratory pressures of 20 and 25 cm H2O. Air leakage was assessed spirometrically. Experiments were performed four times with each tube brand and size with two exemplars of each of the three cuff pressure controllers. Results Owing to immediate cuff pressure correction, tracheal sealing at cuff pressure below inspiratory pressure was reduced in most of the tracheal tube cuffs, except in those with reduced sealing characteristics when using the Pressure Control Tracoe™ compared with the conventional pressure manometer and the VBM Cuff Controller. Tracheal sealing with the Pressure Control Tracoe™ comparable with the other two devices was only achieved at cuff pressures of 20 and 25 cm H2O. Conclusions Automated cuff pressure controllers with rapid pressure correction interfere with the self-sealing mechanism of high sealing HVLP tube cuffs and reduce their improved sealing characteristic

In-line filter included into the syringe infusion pump assembly reduces flow irregularities

Purpose: To evaluate whether an in-line filter inserted in the syringe pump infusion line assembly influences start-up times and flow irregularities during vertical pump displacement at low infusion rates. Methods: Fluid delivery after syringe pump start-up and after vertical displacement of the syringe pump by −50cm was determined gravimetrically at flow rates of 0.5, 1.0 and 2.0mlh−1. Measurements were repeated for each flow rate four times with two different syringe pumps with and without an in-line filter incorporated. Data are shown as median and range. Results: Start-up times were reduced by an in-line filter at 0.5mlh−1 flow rate from 355.5s (0-660) to 115s (0-320), whereas the effect was attenuated at higher flow rates. Pooling of fluid into the infusion system after lowering the infusion syringe pump was halved in all flow rates tested. Amount of infusion bolus after elevating the syringe pump by 50cm was not affected by an in-line filter. Conclusion: In the evaluated model in-line filters help to reduce flow irregularities and delay in drug delivery of syringe pumps at low flow rates and represent an option to optimize continuous administration of highly concentrated short-acting drugs at very small infusion rate

Addressing climate change with behavioral science: a global intervention tournament in 63 countries

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors