Cardiovascular changes induced by targeted mild hypercapnia after out of hospital cardiac arrest. A sub-study of the TAME cardiac arrest trial

Mathias Baumann Melberg; Arnljot Flaa; Geir Øystein Andersen; Kjetil Sunde; Rinaldo Bellomo; Glenn Eastwood; Theresa Mariero Olasveengen; Eirik Qvigstad

doi:10.1016/j.resuscitation.2023.109970

Cardiovascular changes induced by targeted mild hypercapnia after out of hospital cardiac arrest. A sub-study of the TAME cardiac arrest trial

Resuscitation. 2023 Dec:193:109970. doi: 10.1016/j.resuscitation.2023.109970. Epub 2023 Sep 15.

Authors

Mathias Baumann Melberg¹, Arnljot Flaa², Geir Øystein Andersen², Kjetil Sunde³, Rinaldo Bellomo⁴, Glenn Eastwood⁵, Theresa Mariero Olasveengen³, Eirik Qvigstad²

Affiliations

¹ Department of Research and Development, Division of Emergencies and Critical Care, Department of Cardiology, Division of Medicine, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Norway. Electronic address: mb.melberg@gmail.com.
² Department of Cardiology, Division of Medicine, Oslo University Hospital, Oslo, Norway.
³ Department of Anaesthesiology and Intensive Care, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Norway.
⁴ Department of Intensive Care, Austin Hospital, Heidelberg, Victoria, Australia; Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, Victoria, Australia; Department of Critical Care, Melbourne University, Melbourne, Australia; Department of Intensive Care, Royal Melbourne Hospital, Melbourne, Australia.
⁵ Department of Intensive Care, Austin Hospital, Heidelberg, Victoria, Australia; Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, Victoria, Australia.

PMID: 37716401
DOI: 10.1016/j.resuscitation.2023.109970

Abstract

Aim: Hypercapnia may elicit detrimental haemodynamic effects in critically ill patients. We aimed to investigate the consequences of targeted mild hypercapnia versus targeted normocapnia on pulmonary vascular resistance and right ventricular function in patients resuscitated from out-of-hospital cardiac arrest (OHCA).

Methods: Pre-planned, single-centre, prospective, sub-study of the Targeted Therapeutic Mild Hypercapnia After Resuscitated Cardiac Arrest (TAME) trial. Patients were randomised to mild hypercapnia (PaCO₂ = 6.7-7.3 kPa) or normocapnia (PaCO₂ = 4.7-6.0 kPa) for 24 hours. Haemodynamic assessment was performed with right heart catheterisation and serial blood-gas analyses every4th hour for 48 hours.

Results: We studied 84 patients. Mean pH was 7.24 (95% CI 7.22-7.30) and 7.32 (95% CI 7.31-7.34) with hypercapnia and normocapnia, respectively (P-group < 0.001). Pulmonary vascular resistance index (PVRI), pulmonary artery pulsatility index, and right atrial pressure did not differ between groups (P-group > 0.05). Mean cardiac index was higher with mild hypercapnia (P-group < 0.001): 2.0 (95% CI 1.85-2.1) vs 1.6 (95% CI 1.52-1.76) L/min/m². Systemic vascular resistance index was 2579 dyne-sec/cm-5/ m² (95% CI 2356-2830) with hypercapnia, and 3249 dyne-sec/cm-5/ m² (95% CI 2930-3368) with normocapnia (P-group < 0.001). Stroke volumes (P-group = 0.013) and mixed venous oxygen saturation (P-group < 0.001) were higher in the hypercapnic group.

Conclusion: In resuscitated OHCA patients, targeting mild hypercapnia did not increase PVRI or worsen right ventricular function compared to normocapnia. Mild hypercapnia comparatively improved cardiac performance and mixed venous oxygen saturation.

Keywords: Out-of-hospital cardiac arrest; Post-cardiac arrest care; Right heart catheterisation; TAME cardiac arrest trial; Targeted mild hypercapnia.

Publication types

Randomized Controlled Trial

MeSH terms

Blood Gas Analysis
Carbon Dioxide
Hemodynamics
Humans
Hypercapnia* / etiology
Out-of-Hospital Cardiac Arrest* / therapy
Prospective Studies

Substances

Carbon Dioxide