Pragmatic recommendations for the management of COVID-19 patients with shock in low- and middle-income countries

As some patients infected with the novel coronavirus progress to critical illness, a subset will eventually develop shock. High-quality data on management of these patients are scarce, and further investigation will provide valuable information in the context of the pandemic. A group of experts identify a set of pragmatic recommendations for the care of patients with SARS-CoV-2 and shock in resource-limited environments. We define shock as life-threatening circulatory failure that results in inadequate tissue perfusion and cellular dysoxia/hypoxia, and suggest that it can be operationalized via clinical observations. We suggest a thorough evaluation for other potential causes of shock and suggest against indiscriminate testing for coinfections. We suggest the use of the quick Sequential Organ Failure Assessment (qSOFA) as a simple bedside prognostic score for COVID-19 patients and point-of-care ultrasound (POCUS) to evaluate the etiology of shock. Regarding fluid therapy for the treatment of COVID-19 patients with shock in low-middle–income countries, we favor balanced crystalloids and recommend using a conservative fluid strategy for resuscitation. Where available and not prohibited by cost, we recommend using norepinephrine, given its safety profile. We favor avoiding the routine use of central venous or arterial catheters, where availability and costs are strong considerations. We also recommend using low-dose corticosteroids in patients with refractory shock. In addressing targets of resuscitation, we recommend the use of simple bedside parameters such as capillary refill time and suggest that POCUS be used to assess the need for further fluid resuscitation, if available

Cascading and Parallelising Curvilinear Inertial Focusing Systems for High Volume, Wide Size Distribution, Separation and Concentration of Particles

Inertial focusing is a microfluidic based separation and concentration technology that has expanded rapidly in the last few years. Throughput is high compared to other microfluidic approaches although sample volumes have typically remained in the millilitre range. Here we present a strategy for achieving rapid high volume processing with stacked and cascaded inertial focusing systems, allowing for separation and concentration of particles with a large size range, demonstrated here from 30 μm–300 μm. The system is based on curved channels, in a novel toroidal configuration and a stack of 20 devices has been shown to operate at 1 L/min. Recirculation allows for efficient removal of large particles whereas a cascading strategy enables sequential removal of particles down to a final stage where the target particle size can be concentrated. The demonstration of curved stacked channels operating in a cascaded manner allows for high throughput applications, potentially replacing filtration in applications such as environmental monitoring, industrial cleaning processes, biomedical and bioprocessing and many more