Asymmetric Cerebral Perfusion in Comatose Extracorporeal Membrane Oxygenation Patients

Asymmetric cerebral perfusion can occur when extracorporeal membrane oxygenation (ECMO) flow competes with native cardiac circulation. It is unclear whether this phenomenon associates with brain injury. Diffuse correlation spectroscopy (DCS) provides continuous, laser-based, non-invasive, bedside monitoring of relative cerebral blood flow (rCBF). This study measured rCBF in ECMO patients via DCS to determine whether comatose patients experience asymmetric cerebral perfusion. Adults receiving ECMO for any indication were prospectively recruited from 12/2019-3/2021. Patients with prior neurologic injury, scalp/facial lacerations, and SARS-CoV-2 infection were excluded. DCS monitoring was performed daily during ECMO support with sensors placed on bilateral foreheads. Mean arterial pressure (MAP) was continuously recorded from the bedside monitor. The Glasgow Coma Scale (GCS) was assessed by clinical staff multiple times daily with sedation pauses, if possible, per standard of care. rCBF was calculated by comparing continuous cerebral blood flow (CBF) measurements to the daily median CBF, then averaged at each MAP value. Daily rCBF asymmetry was calculated by summing the absolute difference of rCBF between the two hemispheres at each MAP value, normalized for the total MAP range experienced by the patient that day. Twelve subjects were enrolled in this study (ages 21-78, 6 with cardiac arrest, 4 with acute heart failure, 2 with ARDS) and grouped by maximum GCS motor (GCS-M) score during ECMO, with 3 "comatose" subjects (GCS-M <= 4), and 9 "awake" subjects (GCS-M > 4). DCS was performed over 66 sessions with a mean duration of 131.83 +/- 1.13 minutes. Comatose subjects exhibited more rCBF asymmetry than awake subjects (0.28 +/- 0.06 mmHg-1 vs. 0.10 +/- 0.001 mmHg-1, p=0.045). No difference in asymmetry was noted between patients with or without cardiac arrest. We found that comatose ECMO subjects exhibited higher inter-hemispheric rCBF asymmetry over a range of blood pressures than awake subjects. Though our comatose sample is small, further validation of this finding and its causes, such as cerebrovascular dysregulation, is warranted.

Alternatives to tackle climate crisis. How do non-hegemonic vehicles defend the common goods?

This article aims, from the perspective of Journalism studies, to discuss how the representation of solutions or responses associated with the climate crisis can help to sustain or break with the causes of environmental destruction, especially in the context of recovery from the covid-19 pandemic. For this, it analyzes the climate coverage of Colabora and Conexao Planeta in 2020, vehicles considered non-hegemonic dedicated to environmental issues. Based on the Critical Discourse Analysis, it seeks to verify what forms of confronting the climate crisis they make visible. Although the studied vehicles do not follow the logic of mainstream journalism, it is identified that the responses presented in the coverage of climate change in the analyzed vehicles do not always systematically and/or forcefully question the hegemonic system, based on the exploration of nature, offering palliative solutions which contribute to maintaining the status quo.