Francis Bernard
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Francis Bernard has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- Alexandrine Gagnon
Division of Critical Care Medicine, Department of Medicine, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada
1 shared publication - David Williamson
Faculté de pharmacie, Université de Montréal, Montreal, QC, Canada
1 shared publication - Joanie Md Martineau
Division of Critical Care Medicine, Department of Medicine, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada
1 shared publication - Sabrina Bsn Araujo de Franca
Équipe de Recherche en Soins Intensifs, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada
1 shared publication - Virginie Williams
Équipe de Recherche en Soins Intensifs, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada
1 shared publication - Yiorgos Alexandros Cavayas
Department of Medicine, Université de Montréal, Montreal, QC, Canada.
1 shared publication
Latest Publications
- Open Access
- 2 April 2025
- Published by Wolters Kluwer Health in Critical Care Explorations
- Vol. 7 (4) , e1241
Variation in Arterial CO 2 is a Stronger Determinant of Brain Tissue Oxygenation Than its Synchronous Value in Critically Ill Patients With Acute Brain Injury
OBJECTIVES: In critically ill patients with acute brain injury (ABI), maintaining intracranial pressure (ICP) and brain tissue oxygenation (PbtO2) within targets could prevent secondary neurologic injury. Tight control of CO 2 (Paco 2), a potent regulator of cerebrovascular tone, is generally advocated, but its vasomotor effect may be short-lived. Our aim was to compare the effect of the synchronous Paco 2 vs. its variation from a previous baseline on PbtO2 and ICP. DESIGN: We performed a post hoc analysis of a prospective cohort study collecting arterial blood gas (ABG) values alongside synchronous neuromonitoring variables. Linear mixed-effects models were fitted to evaluate the association between Paco 2 and/or Paco 2 variation from its average of the last 8–24 hr vs. PbtO2 and ICP, while controlling for cerebral perfusion pressure and Pao 2. SETTING: Mixed medical-surgical ICU of Sacré-Coeur Hospital, an academic trauma center in Montreal, Canada. PATIENTS: All consecutive adult patients admitted for ABI with ICP and PbtO2 monitoring between May 2017 and November 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 78 patients with 3047 ABG-neuromonitoring couplets. The model using the variation of Paco 2 from its average of the last 24 hr displayed the best performance for the prediction of PbtO2 (coefficient 0.37; 95% CI 0.21–0.53). The strongest predictor of ICP was the variation of Paco 2 from its average of the last 8 hr (coefficient 0.17; 95% CI 0.10–0.23). CONCLUSIONS: Variation in Paco 2 from baseline is a more significant determinant of PbtO2 and ICP than the absolute Paco 2 value at a given time. There may be a baseline vasomotor reset when patients are exposed to a given level of CO2 for 8 to 24 hr. Therefore, sustained intentional manipulation of Paco 2 is unlikely to have lasting effects and slower correction rates of high or low Paco 2 could help prevent brain tissue hypoxia or intracranial hypertension, respectively.
- 2 April 2025
- Published by Wolters Kluwer Health in Critical Care Explorations
- Vol. 7 (4) , e1241
Open AccessVariation in Arterial CO 2 is a Stronger Determinant of Brain Tissue Oxygenation Than its Synchronous Value in Critically Ill Patients With Acute Brain Injury
OBJECTIVES: In critically ill patients with acute brain injury (ABI), maintaining intracranial pressure (ICP) and brain tissue oxygenation (PbtO2) within targets could prevent secondary neurologic injury. Tight control of CO 2 (Paco 2), a potent regulator of cerebrovascular tone, is generally advocated, but its vasomotor effect may be short-lived. Our aim was to compare the effect of the synchronous Paco 2 vs. its variation from a previous baseline on PbtO2 and ICP. DESIGN: We performed a post hoc analysis of a prospective cohort study collecting arterial blood gas (ABG) values alongside synchronous neuromonitoring variables. Linear mixed-effects models were fitted to evaluate the association between Paco 2 and/or Paco 2 variation from its average of the last 8–24 hr vs. PbtO2 and ICP, while controlling for cerebral perfusion pressure and Pao 2. SETTING: Mixed medical-surgical ICU of Sacré-Coeur Hospital, an academic trauma center in Montreal, Canada. PATIENTS: All consecutive adult patients admitted for ABI with ICP and PbtO2 monitoring between May 2017 and November 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 78 patients with 3047 ABG-neuromonitoring couplets. The model using the variation of Paco 2 from its average of the last 24 hr displayed the best performance for the prediction of PbtO2 (coefficient 0.37; 95% CI 0.21–0.53). The strongest predictor of ICP was the variation of Paco 2 from its average of the last 8 hr (coefficient 0.17; 95% CI 0.10–0.23). CONCLUSIONS: Variation in Paco 2 from baseline is a more significant determinant of PbtO2 and ICP than the absolute Paco 2 value at a given time. There may be a baseline vasomotor reset when patients are exposed to a given level of CO2 for 8 to 24 hr. Therefore, sustained intentional manipulation of Paco 2 is unlikely to have lasting effects and slower correction rates of high or low Paco 2 could help prevent brain tissue hypoxia or intracranial hypertension, respectively.