Clinical practice and effect of carbon dioxide on outcomes in mechanically ventilated acute brain-injured patients: a secondary analysis of the ENIO study
Chiara Robba, Denise Battaglini, Abbas Abbas, Ezequiel Sarrió, Raphaël Cinotti, Karim Asehnoune, Fabio Silvio Taccone, Patrícia R. M. Rocco, Marcus J. Schultz, Giuseppe Citerio, Robert D. Stevens, Rafael Badenes, the ENIO collaborators, Paër-Sélim Abback, Anaïs Codorniu, Giuseppe Citerio, V. Sala, Marinella Astuto, Eleonora Tringali, Daniela Alampi, Monica Rocco, Jessica Giuseppina Maugeri, Agrippino Bellissima, Matteo Filippini, Nicoletta Lazzeri, Andrea Cortegiani, Mariachiara Ippolito, Chiara Robba, Denise Battaglini, Patrick Biston, Mohamed Fathi Al-Gharyani, Russell Chabanne, Léo Astier, Benjamin Soyer, Samuel Gaugain, Alice Zimmerli, Urs Pietsch, Miodrag Filipovic, Giovanna Brandi, Giulio Bicciato, Ainhoa Serrano, Berta Monleon, Peter van Vliet, Benjamin Marcel Gerretsen, Iris Xóchitl Ortiz-Macías, Jun Oto, Noriya Enomoto, Tomomichi Matsuda, Nobutaka Masui, Pierre Garçon, Jonathan Zarka, Wytze J. Vermeijden, Alexander D. Cornet, S. Gard, Rafael Cirino Lara Domínguez, Maria Mercedes Bellini, Maria Milagros Gomez Haedo, Laura Lamot, Jose Orquera, Matthieu Biais, Delphine Georges, Arvind Baronial, Roberto Carlos Miranda-Ackerman, Francisco José Barbosa‐Camacho, John Porter, Miguel Lopez-Morales, Thomas Geeraerts, Baptiste Companion, David Pérez-Torres, Estefanía Prol‐Silva, Hana Basheer Yahya, Ala Khaled, Mohamed Ghulam, Cracchiolo Neville Andrea, Palma Maria Daniela, Cristian Deana, Luigi Vetrugno, Manuel J. Rivera Chavez, Rocio Mendoza Trujillo, Vincent Legros, Benjamin Brochet, Olivier Huet, Marie Geslain, Mathieu van der Jagt, Job van Steenkiste, Hazem Ahmed, Alexander Edward Coombs, Jessie Welbourne, Ana Alícia Velarde Pineda, Víctor Hugo Nubert Castillo, Mohammed A. Azab, Ahmed Y. Azzam, David Michael Paul van Meenen, Gilberto Adrian Gasca, Alfredo Arellano, Forttino Galicia-Espinosa, José Carlos García-Ramos, Ghanshyam Yadav, Amarendra Kumar Jha, Vincent Robert-Edan
Abstract
The use of arterial partial pressure of carbon dioxide (PaCO2) as a target intervention to manage elevated intracranial pressure (ICP) and its effect on clinical outcomes remain unclear. We aimed to describe targets for PaCO2 in acute brain injured (ABI) patients and assess the occurrence of abnormal PaCO2 values during the first week in the intensive care unit (ICU). The secondary aim was to assess the association of PaCO2 with in-hospital mortality. We carried out a secondary analysis of a multicenter prospective observational study involving adult invasively ventilated patients with traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), intracranial hemorrhage (ICH), or ischemic stroke (IS). PaCO2 was collected on day 1, 3, and 7 from ICU admission. Normocapnia was defined as PaCO2 > 35 and to 45 mmHg; mild hypocapnia as 32–35 mmHg; severe hypocapnia as 26–31 mmHg, forced hypocapnia as < 26 mmHg, and hypercapnia as > 45 mmHg. 1476 patients (65.9% male, mean age 52 $$\pm$$ 18 years) were included. On ICU admission, 804 (54.5%) patients were normocapnic (incidence 1.37 episodes per person/day during ICU stay), and 125 (8.5%) and 334 (22.6%) were mild or severe hypocapnic (0.52 and 0.25 episodes/day). Forced hypocapnia and hypercapnia were used in 40 (2.7%) and 173 (11.7%) patients. PaCO2 had a U-shape relationship with in-hospital mortality with only severe hypocapnia and hypercapnia being associated with increased probability of in-hospital mortality (omnibus p value = 0.0009). Important differences were observed across different subgroups of ABI patients. Normocapnia and mild hypocapnia are common in ABI patients and do not affect patients' outcome. Extreme derangements of PaCO2 values were significantly associated with increased in-hospital mortality.