Coronavirus disease 2019 and the placenta: A literature review.

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been implicated in the clinical pathology of multiple organs and organ systems. Due to the novelty of the disease, there is a need to review emerging literature to understand the profile of SARS-CoV-2 in the placenta. This review sought to evaluate the literature on the mediators, mechanism of entry, pathogenesis, detection, and pathology of SARS-CoV-2 in the placenta. Systematic literature searches found 96 eligible studies. Our review revealed that SARS-CoV-2 canonical mediators, angiotensin-converting enzyme-2 (ACE2), and transmembrane serine protease-2 (TMPRSS2) are variably expressed in various placenta compartments, including the villous cytotrophoblasts, syncytiotrophoblasts (STBs), and extravillous trophoblasts (EVTs) throughout pregnancy. Placental SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs), including basigin (BSG/CD147), dipeptidyl peptidase-4 (DPP4/CD26), cathepsin B/L (CTL B/L), furin, interferon-induced transmembrane protein (IFITM1-3), and lymphocyte antigen 6E (LY6E) may increase or reduce the permissiveness of the placenta to SARS-CoV-2. EVTs express genes that code for proteins that may drive viral pathogenesis in the placenta. Viral RNA, proteins, and particles were detected primarily in the STBs by in situ hybridization, immunohistochemistry, electron microscopy, and polymerase chain reaction. Placental pathology in SARS-CoV-2-infected placentas included maternal and fetal vascular malperfusion and a generally nonspecific inflammatory-immune response. The localization of SARS-CoV-2 receptors, proteases, and genes involved in coding proteins that drive viral pathogenesis in the placenta predisposes the placenta to SARS-CoV-2 infection variably in all pregnancy trimesters, with antecedent placental pathology. There is a need for further studies to explicate the mechanism of entry and pathogenesis of SARS-CoV-2 in the placenta.

Pragmatic sedation strategies to prevent secondary brain injury in low-resource settings.

Traumatic brain injury is the alteration in brain function due to an external force. It is common and affects millions of people worldwide annually. The World Health Organization estimates that 90% of global deaths caused by injuries occur in low- and middle-income countries, with traumatic brain injury contributing up to half of these trauma-related deaths. Patients with traumatic brain injury in low- and middle-income countries have twice the odds of dying compared with their counterparts in high-income countries. Sedation is a key element of care in the management of traumatic brain injury, used for its neuroprotective effects and to prevent secondary brain injury. While sedatives have the potential to improve outcomes, they can be challenging to administer and have potentially dangerous complications. Sedation in low-resource settings should aim to be effective, safe, affordable and feasible. In this paper, we summarise the indications for sedation in traumatic brain injury, the choice of sedative drugs and the pragmatic management and monitoring of sedated traumatic brain injury patients in low-resource settings.