Abstract
Background: Coronavirus disease 2019 (COVID-19) patients are at high risk of neurological complications consequent to several factors including persistent hypotension. There is a paucity of data on the effects of therapeutic interventions designed to optimize systemic hemodynamics on cerebral autoregulation (CA) in this group of patients.Methods: Single-center, observational prospective study conducted at San Martino Policlinico Hospital, Genoa, Italy, from October 1 to December 15, 2020. Mechanically ventilated COVID-19 patients, who had at least one episode of hypotension and received a passive leg raising (PLR) test, were included. They were then treated with fluid challenge (FC) and/or norepinephrine (NE), according to patients' clinical conditions, at different moments. The primary outcome was to assess the early effects of PLR test and of FC and NE [when clinically indicated to maintain adequate mean arterial pressure (MAP)] on CA (CA index) measured by transcranial Doppler (TCD). Secondary outcomes were to evaluate the effects of PLR test, FC, and NE on systemic hemodynamic variables, cerebral oxygenation (rSo2), and non-invasive intracranial pressure (nICP).Results: Twenty-three patients were included and underwent PLR test. Of these, 22 patients received FC and 14 were treated with NE. The median age was 62 years (interquartile range = 57–68.5 years), and 78% were male. PLR test led to a low CA index [58% (44–76.3%)]. FC and NE administration resulted in a CA index of 90.8% (74.2–100%) and 100% (100–100%), respectively. After PLR test, nICP based on pulsatility index and nICP based on flow velocity diastolic formula was increased [18.6 (17.7–19.6) vs. 19.3 (18.2–19.8) mm Hg, p = 0.009, and 12.9 (8.5–18) vs. 15 (10.5–19.7) mm Hg, p = 0.001, respectively]. PLR test, FC, and NE resulted in a significant increase in MAP and rSo2.Conclusions: In mechanically ventilated severe COVID-19 patients, PLR test adversely affects CA. An individualized strategy aimed at assessing both the hemodynamic and cerebral needs is warranted in patients at high risk of neurological complications.
Highlights
Severe hypoxemic respiratory failure is the main reason for intensive care unit (ICU) admission in coronavirus disease 2019 (COVID-19) patients [1,2,3].COVID-19 is a multisystemic disease [4], with significant implications for the brain [5,6,7]
passive leg raising (PLR) test was positive, and in 22 cases, fluid challenge (FC) was used as first-line treatment
In one patient, who presented with important fluid overload and respiratory failure, NE was started even with a positive PLR, based on the recommendation of ICU physician and patient’s clinical conditions
Summary
Severe hypoxemic respiratory failure is the main reason for intensive care unit (ICU) admission in coronavirus disease 2019 (COVID-19) patients [1,2,3].COVID-19 is a multisystemic disease [4], with significant implications for the brain [5,6,7]. Different mechanisms related to neurological damage have been proposed, such as a direct viral neurotropism, hypercoagulable state, and systemic complications including hypoxia and hypotension [8]. The current target of mean arterial pressure (MAP) commonly used in the general ICU population (>65 mm Hg) [7] may not always be sufficient to ensure adequate cerebral perfusion, as the brain might potentially require higher values of MAP to optimize cerebral perfusion pressure (CPP) and maintain cerebral autoregulation (CA) [9, 10], especially in the COVID19 patients who often present altered cerebrovascular dynamics [5]. Coronavirus disease 2019 (COVID-19) patients are at high risk of neurological complications consequent to several factors including persistent hypotension. There is a paucity of data on the effects of therapeutic interventions designed to optimize systemic hemodynamics on cerebral autoregulation (CA) in this group of patients
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
