Restoring brain connectivity by phrenic nerve stimulation in sedated and mechanically ventilated patients

Thiago Bassi; Elizabeth Rohrs E; Melodie Parfait; Brett C Hannigan; Steven Reynolds; Julien Mayaux; Maxens Decavèle; Jose Herrero; Alexandre Demoule; Thomas Similowski; Martin Dres

doi:10.1038/s43856-024-00662-0

Restoring brain connectivity by phrenic nerve stimulation in sedated and mechanically ventilated patients

Commun Med (Lond). 2024 Nov 18;4(1):235. doi: 10.1038/s43856-024-00662-0.

Authors

Thiago Bassi^{1

2}, Elizabeth Rohrs E³, Melodie Parfait⁴, Brett C Hannigan⁵, Steven Reynolds³, Julien Mayaux⁴, Maxens Decavèle⁴, Jose Herrero^{6

7}, Alexandre Demoule⁴, Thomas Similowski⁸, Martin Dres⁹

Affiliations

¹ Lungpacer Medical Inc., Vancouver, BC, Canada. [email protected].
² Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, ON, Canada. [email protected].
³ Advancing Innovation in Medicine Institute, New Westminster, BC, Canada.
⁴ Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, AP-HP. Sorbonne Université, Hôpital Pitié-Salpêtrière- Service de Médecine Intensive et Réanimation, Paris, France.
⁵ ETH Zurich, Department of Health Sciences and Technology, Zurich, Switzerland.
⁶ The Feinstein Institutes for Medical Research, Northwell Health, New York, NY, 11030, USA.
⁷ Hofstra Northwell School of Medicine, New York, NY, 11549, USA.
⁸ Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, AP-HP. Sorbonne Université, Hôpital Pitié-Salpêtrière- (Département "R3S"), F-75013, Paris, France.
⁹ Sorbonne Université, INSERM, UMRS1158 Neurophysiologie respiratoire expérimentale et clinique, AP-HP. Sorbonne Université, Hôpital Pitié-Salpêtrière- Service de Médecine Intensive et Réanimation, Paris, France. [email protected].

Abstract

Background: In critically ill patients, deep sedation and mechanical ventilation suppress the brain-diaphragm-lung axis and are associated with cognitive issues in survivors.

Methods: This exploratory crossover design study investigates whether phrenic nerve stimulation can enhance brain activity and connectivity in six deeply sedated, mechanically ventilated patients with acute respiratory distress syndrome.

Results: Our findings indicate that adding phrenic stimulation on top of invasive mechanical ventilation in deeply sedated, critically ill, moderate acute respiratory distress syndrome patients increases cortical activity, connectivity, and synchronization in the frontal-temporal-parietal cortices.

Conclusions: Adding phrenic stimulation on top of invasive mechanical ventilation in deeply sedated, critically ill, moderate acute respiratory distress syndrome patients increases cortical activity, connectivity, and synchronization. The observed changes resemble those during diaphragmatic breathing in awake humans. These results suggest that phrenic nerve stimulation has the potential to restore the brain-diaphragm-lung crosstalk when it has been shut down or impaired by mechanical ventilation and sedation. Further research should evaluate the clinical significance of these results.

Plain language summary

Critically ill patients receive sedation and mechanical ventilation as life support measures. Sedation and mechanical ventilation impact the ability of the brain, lungs and diaphragm to communicate as normal. We studied whether stimulating a nerve involved in breathing, called the phrenic nerve, would lead to brain activity in deeply sedated and mechanically ventilated patients. Stimulating the phrenic nerve increased the amount of communication within the brain and the communication seen was similar to that seen in studies in healthy participants. These data suggest that stimulating the phrenic nerve could restore the brain-diaphragm-lung crosstalk when it has been shut down or impaired by mechanical ventilation and sedation which could prevent cognitive impairment in critically ill patients.