Shining a light on cerebral autoregulation: Are we anywhere near the truth?

The near-infrared spectroscopy (NIRS)-derived cerebral oximetry index (COx) has become popularized for non-invasive neuromonitoring of cerebrovascular function in post-cardiac arrest patients with hypoxic-ischemic brain injury (HIBI). We provide commentary on the physiologic underpinnings and assumptions of NIRS and the COx, potential confounds in the context of HIBI, and the implications for the assessment of cerebral autoregulation.

Impact of Skin Pigmentation on Cerebral Regional Saturation of Oxygen Using Near-Infrared Spectroscopy: A Systematic Review.

OBJECTIVES: Near-infrared spectroscopy (NIRS) is used in critical care settings to measure regional cerebral tissue oxygenation (rSo2). However, the accuracy of such measurements has been questioned in darker-skinned individuals due to the confounding effects of light absorption by melanin. In this systematic review, we aim to synthesize the available evidence on the effect of skin pigmentation on rSo2 readings. DATA SOURCES: We systematically searched MEDLINE, Cochrane Database of Systematic Reviews, Embase, and Google Scholar from inception to July 1, 2023. STUDY SELECTION: In compliance with our PROSPERO registration (CRD42022347548), we selected articles comparing rSo2 measurements in adults either between racial groups or at different levels of skin pigmentation. Two independent reviewers conducted full-text reviews of all potentially relevant articles. DATA EXTRACTION: We extracted data on self-reported race or level of skin pigmentation and mean rSo2 values. DATA SYNTHESIS: Of the 11,495 unique records screened, two studies (n = 7,549) met our inclusion criteria for systematic review. Sun et al (2015) yielded significantly lower rSo2 values for African Americans compared with Caucasians, whereas Stannard et al (2021) found little difference between self-reported racial groups. This discrepancy is likely because Stannard et al (2021) used a NIRS platform which specifically purports to control for the effects of melanin. Several other studies that did not meet our inclusion criteria corroborated the notion that skin pigmentation results in lower rSo2 readings. CONCLUSIONS: Skin pigmentation likely results in attenuated rSo2 readings. However, the magnitude of this effect may depend on the specific NIRS platform used.

Cerebral hemodynamics after cardiac arrest: implications for clinical management.

Following resuscitation from cardiac arrest, hypoxic ischemic brain injury (HIBI) ensues, which is the primary determinant of adverse outcome. The pathophysiology of HIBI can be compartmentalized into primary and secondary injury, resulting from cerebral ischemia during cardiac arrest and reperfusion following successful resuscitation, respectively. During the secondary injury phase, increased attention has been directed towards the optimization of cerebral oxygen delivery to prevent additive injury to the brain. During this phase, cerebral hemodynamics are characterized by early hyperemia following resuscitation and then a protracted phase of cerebral hypoperfusion termed "no-reflow" during which additional hypoxic-ischemic injury can occur. As such, identification of therapeutic strategies to optimize cerebral delivery of oxygen is at the forefront of HIBI research. Unfortunately, randomized control trials investigating the manipulation of arterial carbon dioxide tension and mean arterial pressure augmentation as methods to potentially improve cerebral oxygen delivery have shown no impact on clinical outcomes. Emerging literature suggests differential patient-specific phenotypes may exist in patients with HIBI. The potential to personalize therapeutic strategies in the critical care setting based upon patient-specific pathophysiology presents an attractive strategy to improve HIBI outcomes. Herein, we review the cerebral hemodynamic pathophysiology of HIBI, discuss patient phenotypes as it pertains to personalizing care, as well as suggest future directions.

High-normal versus low-normal mean arterial pressure thresholds in critically ill patients: a systematic review and meta-analysis of randomized trials.

PURPOSE: Targeted blood pressure thresholds remain unclear in critically ill patients. Two prior systematic reviews have not shown differences in mortality with a high mean arterial pressure (MAP) threshold, but there have been new studies published since. Thus, we conducted an updated systematic review and meta-analysis of randomized controlled trials (RCTs) that compared the effect of a high-normal vs low-normal MAP on mortality, favourable neurologic outcome, need for renal replacement therapy, and adverse vasopressor-induced events in critically ill patients. SOURCE: We searched six databases from inception until 1 October 2022 for RCTs of critically ill patients targeted to either a high-normal vs a low-normal MAP threshold for at least 24 hr. We assessed study quality using the revised Cochrane risk-of-bias 2 tool and the risk ratio (RR) was used as the summary measure of association. We used the Grading of Recommendations Assessment, Development, and Evaluation framework to assess the certainty of evidence. PRINCIPAL FINDINGS: We included eight RCTs with 4,561 patients. Four trials were conducted in patients following out-of-hospital cardiac arrest, two in patients with distributive shock requiring vasopressors, one in patients with septic shock, and one in patients with hepatorenal syndrome. The pooled RRs for mortality (eight RCTs; 4,439 patients) and favourable neurologic outcome (four RCTs; 1,065 patients) were 1.06 (95% confidence interval [CI], 0.99 to 1.14; moderate certainty) and 0.99 (95% CI, 0.90 to 1.08; moderate certainty), respectively. The RR for the need for renal replacement therapy (four RCTs; 4,071 patients) was 0.97 (95% CI, 0.87 to 1.08; moderate certainty). There was no statistical between-study heterogeneity across all outcomes. CONCLUSION: This updated systematic review and meta-analysis of RCTs found no differences in mortality, favourable neurologic outcome, or the need for renal replacement therapy between critically ill patients assigned to a high-normal vs low-normal MAP target. STUDY REGISTRATION: PROSPERO (CRD42022307601); registered 28 February 2022.

RéSUMé: OBJECTIF: Les seuils de pression artérielle ciblés demeurent incertains chez les patient·es gravement malades. Deux revues systématiques antérieures n'ont pas montré de différences dans la mortalité avec un seuil élevé de pression artérielle moyenne (PAM), mais de nouvelles études ont été publiées depuis. Pour cette raison, nous avons réalisé une revue systématique mise à jour et une méta-analyse d'études randomisées contrôlées (ERC) comparant l'effet d'une PAM normale élevée vs normale faible sur la mortalité, les devenirs neurologiques favorables, la nécessité d'un traitement substitutif de l'insuffisance rénale et les événements indésirables induits par les vasopresseurs chez les patient·es gravement malades. SOURCES: Nous avons effectué des recherches dans six bases de données depuis leur création jusqu'au 1er octobre 2022 pour trouver des ERC portant sur des patient·es gravement malades chez lesquel·les un seuil de PAM normale élevée ou normale faible a été ciblé pendant au moins 24 heures. Nous avons évalué la qualité des études à l'aide de l'outil de risque de biais 2 révisé de Cochrane, et le risque relatif (RR) a été utilisé comme mesure sommaire de l'association. Nous avons utilisé le système de notation GRADE (Grading of Recommendations Assessment, Development, and Evaluation) pour évaluer la certitude des données probantes. CONSTATATIONS PRINCIPALES: Nous avons inclus huit ERC portant sur 4561 personnes traitées. Quatre études ont été menées chez des patient·es à la suite d'un arrêt cardiaque hors de l'hôpital, deux chez des patient·es présentant un choc distributif nécessitant des vasopresseurs, une chez des patient·es présentant un choc septique et une chez des patient·es atteint·es d'un syndrome hépato-rénal. Les RR combinés pour la mortalité (huit ERC; 4439 personnes) et les devenirs neurologiques favorables (quatre ERC; 1065 personnes) étaient respectivement de 1,06 (intervalle de confiance [IC] à 95 %, 0,99 à 1,14; certitude modérée) et de 0,99 (IC 95 %, 0,90 à 1,08; certitude modérée). Le RR pour le besoin de traitement substitutif de l'insuffisance rénale (quatre ERC; 4071 patient·es) était de 0,97 (IC 95 %, 0,87 à 1,08; certitude modérée). Il n'y avait pas d'hétérogénéité statistique entre les études pour tous les critères d'évaluation. CONCLUSION: Ces revue systématique et méta-analyse mises à jour des ERC n'ont révélé aucune différence dans la mortalité, les devenirs neurologiques favorables ou la nécessité d'un traitement substitutif de l'insuffisance rénale entre les patient·es gravement malades assigné·es à une cible de PAM normale élevée vs normale faible. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42022307601); enregistrée le 28 février 2022.

Non-contrast-enhancing subdural empyema: illustrative case.

BACKGROUND: Subdural empyema (SDE) is a life-threatening intracranial infection that, without timely surgical intervention and appropriate antibiotic treatment, is inevitably fatal. SDE is classically recognized on brain imaging as a subdural collection surrounded by a contrast-enhancing ring. OBSERVATIONS: The authors describe the case of a 41-year-old male with clinical features consistent with SDE but without any contrast enhancement on multiple computed tomography scans obtained more than 48 hours apart. Given the high clinical suspicion for SDE, a craniotomy was performed that demonstrated frank pus that eventually grew Streptococcus pyogenes. LESSONS: This case demonstrates that SDE may present without ring enhancement on contrast-enhanced imaging. In critically ill patients with a high clinical suspicion for SDE despite lack of contrast enhancement, we demonstrate that exploratory burr holes or craniotomy can provide diagnostic confirmation and source control.

Therapeutic hypothermia attenuates physiologic, histologic, and metabolomic markers of injury in a porcine model of acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a lung injury characterized by noncardiogenic pulmonary edema and hypoxic respiratory failure. The purpose of this study was to investigate the effects of therapeutic hypothermia on short-term experimental ARDS. Twenty adult female Yorkshire pigs were divided into four groups (n = 5 each): normothermic control (C), normothermic injured (I), hypothermic control (HC), and hypothermic injured (HI). Acute respiratory distress syndrome was induced experimentally via intrapulmonary injection of oleic acid. Target core temperature was achieved in the HI group within 1 h of injury induction. Cardiorespiratory, histologic, cytokine, and metabolomic data were collected on all animals prior to and following injury/sham. All data were collected for approximately 12 h from the beginning of the study until euthanasia. Therapeutic hypothermia reduced injury in the HI compared to the I group (histological injury score = 0.51 ± 0.18 vs. 0.76 ± 0.06; p = 0.02) with no change in gas exchange. All groups expressed distinct phenotypes, with a reduction in pro-inflammatory metabolites, an increase in anti-inflammatory metabolites, and a reduction in inflammatory cytokines observed in the HI group compared to the I group. Changes to respiratory system mechanics in the injured groups were due to increases in lung elastance (E) and resistance (R) (ΔE from pre-injury = 46 ± 14 cmH2 O L-1 , p < 0.0001; ΔR from pre-injury: 3 ± 2 cmH2 O L-1  s- , p = 0.30) rather than changes to the chest wall (ΔE from pre-injury: 0.7 ± 1.6 cmH2 O L-1 , p = 0.99; ΔR from pre-injury: 0.6 ± 0.1 cmH2 O L-1  s- , p = 0.01). Both control groups had no change in respiratory mechanics. In conclusion, therapeutic hypothermia can reduce markers of injury and inflammation associated with experimentally induced short-term ARDS.

Neurologic Prognostication After Cardiac Arrest Using Brain Biomarkers: A Systematic Review and Meta-analysis.

IMPORTANCE: Brain injury biomarkers released into circulation from the injured neurovascular unit are important prognostic tools in patients with cardiac arrest who develop hypoxic ischemic brain injury (HIBI) after return of spontaneous circulation (ROSC). OBJECTIVE: To assess the neuroprognostic utility of bloodborne brain injury biomarkers in patients with cardiac arrest with HIBI. DATA SOURCES: Studies in electronic databases from inception to September 15, 2021. These databases included MEDLINE, Embase, Evidence-Based Medicine Reviews, CINAHL, Cochrane Database of Systematic Reviews, and the World Health Organization Global Health Library. STUDY SELECTION: Articles included in this systmatic review and meta-analysis were independently assessed by 2 reviewers. We included studies that investigated neuron-specific enolase, S100 calcium-binding protein ß, glial fibrillary acidic protein, neurofilament light, tau, or ubiquitin carboxyl hydrolase L1 in patients with cardiac arrest aged 18 years and older for neurologic prognostication. We excluded studies that did not (1) dichotomize neurologic outcome as favorable vs unfavorable, (2) specify the timing of blood sampling or outcome determination, or (3) report diagnostic test accuracy or biomarker concentration. DATA EXTRACTION AND SYNTHESIS: Data on the study design, inclusion and exclusion criteria, brain biomarkers levels, diagnostic test accuracy, and neurologic outcome were recorded. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. MAIN OUTCOMES AND MEASURES: Summary receiver operating characteristic curve analysis was used to calculate the area under the curve, sensitivity, specificity, and optimal thresholds for each biomarker. Risk of bias and concerns of applicability were assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. RESULTS: We identified 2953 studies, of which 86 studies with 10 567 patients (7777 men [73.6] and 2790 women [26.4]; pooled mean [SD] age, 62.8 [10.2] years) were included. Biomarker analysis at 48 hours after ROSC demonstrated that neurofilament light had the highest predictive value for unfavorable neurologic outcome, with an area under the curve of 0.92 (95% CI, 0.84-0.97). Subgroup analyses of patients treated with targeted temperature management and those who specifically had an out-of-hospital cardiac arrest showed similar results (targeted temperature management, 0.92 [95% CI, 0.86-0.95] and out-of-hospital cardiac arrest, 0.93 [95% CI, 0.86-0.97]). CONCLUSIONS AND RELEVANCE: Neurofilament light, which reflects white matter damage and axonal injury, yielded the highest accuracy in predicting neurologic outcome in patients with HIBI at 48 hours after ROSC. TRIAL REGISTRATION: PROSPERO Identifier: CRD42020157366.

The Use of Near-Infrared Spectroscopy and/or Transcranial Doppler as Non-Invasive Markers of Cerebral Perfusion in Adult Sepsis Patients With Delirium: A Systematic Review.

BACKGROUND: Several studies have previously reported the presence of altered cerebral perfusion during sepsis. However, the role of non-invasive neuromonitoring, and the impact of altered cerebral perfusion, in sepsis patients with delirium remains unclear. METHODS: We performed a systematic review of studies that used near-infrared spectroscopy (NIRS) and/or transcranial Doppler (TCD) to assess adults (≥18 years) with sepsis and delirium. From study inception to July 28, 2020, we searched the following databases: Ovid MedLine, Embase, Cochrane Library, and Web of Science. RESULTS: Of 1546 articles identified, 10 met our inclusion criteria. Although NIRS-derived regional cerebral oxygenation was consistently lower, this difference was only statistically significant in one study. TCD-derived cerebral blood flow velocity was inconsistent across studies. Importantly, both impaired cerebral autoregulation during sepsis and increased cerebrovascular resistance were associated with delirium during sepsis. However, the heterogeneity in NIRS and TCD devices, duration of recording (from 10 seconds to 72 hours), and delirium assessment methods (e.g., electronic medical records, confusion assessment method for the intensive care unit), precluded meta-analysis. CONCLUSION: The available literature demonstrates that cerebral perfusion disturbances may be associated with delirium in sepsis. However, future investigations will require consistent definitions of delirium, delirium assessment training, harmonized NIRS and TCD assessments (e.g., consistent measurement site and length of recording), as well as the quantification of secondary and tertiary variables (i.e., Cox, Mxa, MAPOPT), in order to fully assess the relationship between cerebral perfusion and delirium in patients with sepsis.

Brain Hypoxia Is Associated With Neuroglial Injury in Humans Post-Cardiac Arrest.

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Intraparenchymal Neuromonitoring of Cerebral Fat Embolism Syndrome.

OBJECTIVES: We aimed to characterize the cerebrovascular physiology of cerebral fat embolism using invasive multimodal neuromonitoring. DATA SOURCES: ICU, Vancouver General Hospital, Vancouver, BC, Canada. STUDY SELECTION: Case report. DATA EXTRACTION: Patient monitoring software (ICM+, Cambridge, United Kingdom), clinical records, and surgical records. DATA SYNTHESIS: None. CONCLUSIONS: Our integrated assessment of the cerebrovascular physiology of fat embolism syndrome provides a physiologic basis to investigate the importance of augmenting mean arterial pressure to optimize cerebral oxygen delivery for the mitigation of long-term neurologic ischemic sequelae of cerebral fat embolism.

Duraplasty in Traumatic Thoracic Spinal Cord Injury: Impact on Spinal Cord Hemodynamics, Tissue Metabolism, Histology, and Behavioral Recovery Using a Porcine Model.

After acute traumatic spinal cord injury (SCI), the spinal cord can swell to fill the subarachnoid space and become compressed by the surrounding dura. In a porcine model of SCI, we performed a duraplasty to expand the subarachnoid space around the injured spinal cord and evaluated how this influenced acute intraparenchymal hemodynamic and metabolic responses, in addition to histological and behavioral recovery. Female Yucatan pigs underwent a T10 SCI, with or without duraplasty. Using microsensors implanted into the spinal cord parenchyma, changes in blood flow (ΔSCBF), oxygenation (ΔPO2), and spinal cord pressure (ΔSCP) during and after SCI were monitored, alongside metabolic responses. Behavioral recovery was tested weekly using the Porcine Injury Behavior Scale (PTIBS). Thereafter, spinal cords were harvested for tissue sparing analyses. In both duraplasty and non-animals, the ΔSCP increased ∼5 mm Hg in the first 6 h post-injury. After this, the SCP appeared to be slightly reduced in the duraplasty animals, although the group differences were not statistically significant after controlling for injury severity in terms of impact force. During the first seven days post-SCI, the ΔSCBF or ΔPO2 values were not different between the duraplasty and control animals. Over 12 weeks, there was no improvement in hindlimb locomotion as assessed by PTIBS scores and no reduction in tissue damage at the injury site in the duraplasty animals. In our porcine model of SCI, duraplasty did not provide any clear evidence of long-term behavioral or tissue sparing benefit after SCI.

Goal-Directed Care Using Invasive Neuromonitoring Versus Standard of Care After Cardiac Arrest: A Matched Cohort Study.

PURPOSE: Following return of spontaneous circulation after cardiac arrest, hypoxic ischemic brain injury is the primary cause of mortality and disability. Goal-directed care using invasive multimodal neuromonitoring has emerged as a possible resuscitation strategy. We evaluated whether goal-directed care was associated with improved neurologic outcome in hypoxic ischemic brain injury patients after cardiac arrest. DESIGN: Retrospective, single-center, matched observational cohort study. SETTING: Quaternary academic medical center. PATIENTS: Adult patients admitted to the ICU following return of spontaneous circulation postcardiac arrest with clinical evidence of hypoxic ischemic brain injury defined as greater than or equal to 10 minutes of cardiac arrest with an unconfounded postresuscitation Glasgow Coma Scale of less than or equal to 8. INTERVENTIONS: We compared patients who underwent goal-directed care using invasive neuromonitoring with those treated with standard of care (using both total and matched groups). MEASUREMENTS AND MAIN RESULTS: Goal-directed care patients were matched 1:1 to standard of care patients using propensity scores and exact matching. The primary outcome was a 6-month favorable neurologic outcome (Cerebral Performance Category of 1 or 2). We included 65 patients, of whom 21 received goal-directed care and 44 patients received standard of care. The median age was 50 (interquartile range, 35-61), 48 (74%) were male, and seven (11%) had shockable rhythms. Favorable neurologic outcome at 6 months was significantly greater in the goal-directed care group (n = 9/21 [43%]) compared with the matched (n = 2/21 [10%], p = 0.016) and total (n = 8/44 [18%], p = 0.034) standard of care groups. Goal-directed care group patients had higher mean arterial pressure (p < 0.001 vs total; p = 0.0060 vs matched) and lower temperature (p = 0.007 vs total; p = 0.041 vs matched). CONCLUSIONS: In this preliminary study of patients with hypoxic ischemic brain injury postcardiac arrest, goal-directed care guided by invasive neuromonitoring was associated with a 6-month favorable neurologic outcome (Cerebral Performance Category 1 or 2) versus standard of care. Significant work is required to confirm this finding in a prospectively designed study.

Transport Time and Mortality in Critically Ill Patients with Severe Traumatic Brain Injury.

PURPOSE: Severe traumatic brain injury (TBI) is a major cause of morbidity and mortality in critically ill patients. Pre-hospital care and transportation time may impact their outcomes. METHODS: Using the British Columbia Trauma Registry, we included 2,860 adult (≥18 years) patients with severe TBI (abbreviated injury scale head score ≥4), who were admitted to an intensive care unit (ICU) in a centre with neurosurgical services from January 1, 2000 to March 31, 2013. We evaluated the impact of transportation time (time of injury to time of arrival at a neurosurgical trauma centre) on in-hospital mortality and discharge disposition, adjusting for age, sex, year of injury, injury severity score (ISS), revised trauma score at the scene, location of injury, socio-economic status and direct versus indirect transfer. RESULTS: Patients had a median age of 43 years (interquartile range [IQR] 26-59) and 676 (23.6%) were female. They had a median ISS of 33 (IQR 26-43). Median transportation time was 80 minutes (IQR 40-315). ICU and hospital length of stay were 6 days (IQR 2-12) and 20 days (IQR 7-42), respectively. Six hundred and ninety-six (24.3%) patients died in hospital. After adjustment, there was no significant impact of transportation time on in-hospital mortality (odds ratio 0.98, 95% confidence interval 0.95-1.01). There was also no significant effect on discharge disposition. CONCLUSIONS: No association was found between pre-hospital transportation time and in-hospital mortality in critically ill patients with severe TBI.

Determining Optimal Mean Arterial Pressure After Cardiac Arrest: A Systematic Review.

The use of cerebral autoregulation monitoring to identify patient-specific optimal mean arterial pressure (MAPOPT) has emerged as a technique to augment cerebral oxygen delivery in post-cardiac arrest patients. Our systematic review aims to determine (a) the average MAPOPT in these patients, (b) the feasibility of identifying MAPOPT, (c) the brain tissue oxygenation levels when MAP is within proximity to the MAPOPT and (d) the relationship between neurological outcome and MAPOPT-targeted resuscitation strategies. We carried out this review in accordance with the PRISMA guidelines. We included all studies that used cerebral autoregulation to determine MAPOPT in adult patients (> 16 years old) who achieved return of spontaneous circulation (ROSC) following cardiac arrest. All studies had to include our primary outcome of MAPOPT. We excluded studies where the patients had any history of traumatic brain injury, ischemic stroke or intracranial hemorrhage. We identified six studies with 181 patients. There was wide variability in cerebral autoregulation monitoring methods, length of monitoring, calculation and reporting of MAPOPT. Amongst all studies, the median or mean MAPOPT was consistently above 65 mmHg (range 70-114 mmHg). Definitions of feasibility varied among studies and were difficult to summarize. Only one study noted that brain tissue oxygenation increased as patients' MAP approached MAPOPT. There was no consistent association between targeting MAPOPT and improved neurological outcome. There is considerable heterogeneity in MAPOPT due to differences in monitoring methods of autoregulation. Further research is needed to assess the clinical utility of MAPOPT-guided strategies on decreasing secondary injury and improving neurological outcomes after ROSC.

Caractéristiques de départ et issues chez des patients atteints de COVID-19 hospitalisés dans des unités de soins intensifs à Vancouver (Canada) : série de cas.

CONTEXTE: La pandémie de maladie à coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2) est associée à une mortalité élevée dans les unités de soins intensifs (USI). Nous avons voulu décrire les caractéristiques cliniques et les issues des patients gravement atteints de la maladie à coronavirus 2019 (COVID-19) en contexte canadien. MÉTHODES: Nous avons procédé à l'étude rétrospective d'une série de cas graves d'infection au SRAS-CoV-2 confirmée en laboratoire hospitalisés dans l'une des 6 USI du Vancouver métropolitain, en Colombie-Britannique (Canada), entre le 21 février et le 14 avril 2020. Les données démographiques, les renseignements sur la prise en charge et les résultats ont été recueillis à partir des dossiers médicaux, électroniques ou non, des patients. RÉSULTATS: Entre le 21 février et le 14 avril 2020, 117 patients ont été admis dans une USI avec un diagnostic confirmé de COVID-19. L'âge médian était de 69 ans (écart interquartile [EI] 60­75 ans); et 38 (32,5 %) étaient des femmes. Au moins une comorbidité était présente chez 86 patients (73,5 %). La ventilation mécanique a été nécessaire chez 74 patients (63,2 %). La durée de la ventilation mécanique a été de 13,5 jours (EI 8­22 jours) dans l'ensemble et de 11 jours (II 6­16) chez les patients qui ont reçu leur congé de l'USI. Du tocilizumab a été administré à 4 patients et de l'hydroxychloroquine à 1 patient. En date du 5 mai 2020, 18 patients (15,4 %) étaient décédés, 12 (10,3 %) étaient toujours à l'USI, 16 (13,7 %) avaient obtenu leur congé de l'USI, mais restaient hospitalisés, et 71 (60,7 %) avaient pu retourner à la maison. INTERPRÉTATION: Dans cette étude, la mortalité chez les patients gravement malades de la COVID-19 hospitalisés dans une USI a été moins élevée que chez les patients d'études précédentes. Ces résultats donnent à penser que le pronostic des cas graves de COVID-19 pourrait ne pas être aussi sombre que ce qui avait d'abord été rapporté.