Annika Nelskylä1, Jouni Nurmi2, Milla Jousi2, Alexey Schramko3, Eero Mervaala4, Giuseppe Ristagno5, Markus B Skrifvars6. 1. Division of Intensive Care, Department of Anaesthesiology, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Finland. 2. Emergency Medicine and Services, Helsinki University Hospital and Department of Emergency Medicine, University of Helsinki, Finland. 3. Division of Anaesthesia, Department of Anaesthesiology, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Finland. 4. Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 5. Department of Cardiovascular Research, IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy. 6. Division of Intensive Care, Department of Anaesthesiology, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Finland; Australian and New Zealand Intensive Care Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. Electronic address: markus.skrifvars@monash.edu.
Abstract
BACKGROUND AND AIM: We hypothesised that the use of 50% compared to 100% oxygen maintains cerebral oxygenation and ameliorates the disturbance of cardiac mitochondrial respiration during cardiopulmonary resuscitation (CPR). METHODS: Ventricular fibrillation (VF) was induced electrically in anaesthetised healthy adult pigs and left untreated for seven minutes followed by randomisation to manual ventilation with 50% or 100% oxygen and mechanical chest compressions (LUCAS®). Defibrillation was performed at thirteen minutes and repeated if necessary every two minutes with 1mg intravenous adrenaline. Cerebral oxygenation was measured with near-infrared spectroscopy (rSO2, INVOS™5100C Cerebral Oximeter) and with a probe (NEUROVENT-PTO, RAUMEDIC) in the frontal brain cortex (PbO2). Heart biopsies were obtained 20min after the return of spontaneous circulation (ROSC) with an analysis of mitochondrial respiration (OROBOROS Instruments Corp., Innsbruck, Austria), and compared to four control animals without VF and CPR. Brain rSO2 and PbO2 were log transformed and analysed with a mixed linear model and mitochondrial respiration with an analysis of variance. RESULTS: Of the twenty pigs, one had a breach of protocol and was excluded, leaving nine pigs in the 50% group and ten in the 100% group. Return of spontaneous circulation (ROSC) was achieved in six pigs in the 50% group and eight in the 100% group. The rSO2 (p=0.007) was lower with FiO2 50%, but the PbO2 was not (p=0.93). After ROSC there were significant interactions between time and FiO2 regarding both rSO2 (p=0.001) and PbO2 (p=0.004). Compared to the controls, mitochondrial respiration was decreased, with adenosine diphosphate (ADP) levels of 57 (17)pmols-1mg-1 compared to 92 (23)pmols-1mg-1 (p=0.008), but there was no difference between different oxygen fractions (p=0.79). CONCLUSIONS: The use of 50% oxygen during CPR results in lower cerebral oximetry values compared to 100% oxygen but there is no difference in brain tissue oxygen. Cardiac arrest disturbs cardiac mitochondrial respiration, but it is not alleviated with the use of 50% compared to 100% oxygen (Ethical and hospital approvals ESAVI/1077/04.10.07/2016 and HUS/215/2016, §7 30.3.2016, Funding Helsinki University and others).
BACKGROUND AND AIM: We hypothesised that the use of 50% compared to 100% oxygen maintains cerebral oxygenation and ameliorates the disturbance of cardiac mitochondrial respiration during cardiopulmonary resuscitation (CPR). METHODS:Ventricular fibrillation (VF) was induced electrically in anaesthetised healthy adult pigs and left untreated for seven minutes followed by randomisation to manual ventilation with 50% or 100% oxygen and mechanical chest compressions (LUCAS®). Defibrillation was performed at thirteen minutes and repeated if necessary every two minutes with 1mg intravenous adrenaline. Cerebral oxygenation was measured with near-infrared spectroscopy (rSO2, INVOS™5100C Cerebral Oximeter) and with a probe (NEUROVENT-PTO, RAUMEDIC) in the frontal brain cortex (PbO2). Heart biopsies were obtained 20min after the return of spontaneous circulation (ROSC) with an analysis of mitochondrial respiration (OROBOROS Instruments Corp., Innsbruck, Austria), and compared to four control animals without VF and CPR. Brain rSO2 and PbO2 were log transformed and analysed with a mixed linear model and mitochondrial respiration with an analysis of variance. RESULTS: Of the twenty pigs, one had a breach of protocol and was excluded, leaving nine pigs in the 50% group and ten in the 100% group. Return of spontaneous circulation (ROSC) was achieved in six pigs in the 50% group and eight in the 100% group. The rSO2 (p=0.007) was lower with FiO2 50%, but the PbO2 was not (p=0.93). After ROSC there were significant interactions between time and FiO2 regarding both rSO2 (p=0.001) and PbO2 (p=0.004). Compared to the controls, mitochondrial respiration was decreased, with adenosine diphosphate (ADP) levels of 57 (17)pmols-1mg-1 compared to 92 (23)pmols-1mg-1 (p=0.008), but there was no difference between different oxygen fractions (p=0.79). CONCLUSIONS: The use of 50% oxygen during CPR results in lower cerebral oximetry values compared to 100% oxygen but there is no difference in brain tissue oxygen. Cardiac arrest disturbs cardiac mitochondrial respiration, but it is not alleviated with the use of 50% compared to 100% oxygen (Ethical and hospital approvals ESAVI/1077/04.10.07/2016 and HUS/215/2016, §7 30.3.2016, Funding Helsinki University and others).
Authors: Filippo Annoni; Lorenzo Peluso; Lucas Akira Hirai; Giovanni Babini; Amina Khaldi; Antoine Herpain; Lorenzo Pitisci; Lorenzo Ferlini; Bruno Garcia; Fabio Silvio Taccone; Jacques Creteur; Fuhong Su Journal: Animal Model Exp Med Date: 2022-01-28
Authors: Mervyn Singer; Paul J Young; John G Laffey; Pierre Asfar; Fabio Silvio Taccone; Markus B Skrifvars; Christian S Meyhoff; Peter Radermacher Journal: Crit Care Date: 2021-12-19 Impact factor: 9.097