Optimizing cerebral oxygen delivery after cardiac arrest: A role for neuromonitoring

Restoration and maintenance of end-organ oxygen delivery are fundamental goals of critical care medicine. 1. Smith J. Penninckx J.J. Kampschulte S. Safar P. Need for oxygen enrichment in myocardial infarction, shock and following cardiac arrest. Acta Anaesthesiol Scand Suppl. 1968; 29: 127-145 Crossref PubMed Scopus (8) Google Scholar Measuring mixed or central venous oxygen saturation allows the adequacy of systemic oxygen delivery to be estimated. When oxygen delivery is insufficient to meet metabolic demand, the fraction of arterial oxygen extracted and utilized by tissue increases and venous oxygen saturation falls, eventually heralding cellular hypoxia, anaerobic metabolism, and organ damage. While systemic venous saturation monitoring has a biological rationale and face validity, randomized controlled trials have failed to demonstrate benefit to patient centered outcomes. 2. Harvey S. Harrison D.A. Singer M. et al. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): a randomised controlled trial. Lancet. 2005; 366: 472-477 Abstract Full Text Full Text PDF PubMed Scopus (794) Google Scholar , 3. Rhodes A. Cusack R.J. Newman P.J. Grounds R.M. Bennett E.D. A randomised, controlled trial of the pulmonary artery catheter in critically ill patients. Intensive Care Med. 2002; 28: 256-264 Crossref PubMed Scopus (213) Google Scholar This may be explained in part by complexity identifying the correct underlying pathophysiologic cause(s) of abnormal values. 4. Woda R.P. Dzwonczyk R.D. Orlowski J.P. Van Lente F. Lynn L.A. Effect of measurement error on calculated variables of oxygen transport. J Appl Physiol. 1985; 1996: 559-563 Google Scholar Thus, there remains great interest in pushing oxygen monitoring to the level of the end organs that drive clinical outcomes. 5. Ellis C.G. Jagger J. Sharpe M. The microcirculation as a functional system. Crit Care. 2005; 9: S3-S8 Crossref PubMed Scopus (122) Google Scholar , 6. Stocchetti N. Longhi L. Moving from macro- to microcirculation in head injury. Crit Care Med. 2004; 32: 1429-1430 Crossref PubMed Scopus (3) Google Scholar Brain injury is the primary determinant of outcome in comatose patients resuscitated from out-of-hospital cardiac arrest (OHCA), and prevention of secondary brain injury may save lives and improve quality of recovery. 7. Sekhon M.S. Ainslie P.N. Griesdale D.E. Clinical pathophysiology of hypoxic ischemic brain injury after cardiac arrest: a "two-hit" model. Crit Care. 2017; 21: 90 Crossref PubMed Scopus (236) Google Scholar Akin to systemic venous oxygen monitoring, it is possible that insight into the dynamics of cerebral oxygen delivery and consumption can be gained by sampling cerebral venous outflow at the jugular bulb. 8. Macmillan C.S. Andrews P.J. Cerebrovenous oxygen saturation monitoring: practical considerations and clinical relevance. Intensive Care Med. 2000; 26: 1028-1036 Crossref PubMed Scopus (83) Google Scholar Elevated jugular venous oxygen saturation after cardiac arrestResuscitationVol. 169PreviewWe performed a retrospective analysis of our earlier study on cerebral oxygenation monitoring by jugular venous oximetry (SjvO2) in patients of out-of-hospital cardiac arrest (OHCA). The study was focused on high SjvO2 values (≥75%) and their association with neurological outcomes and serum neuron-specific enolase (NSE) concentration. Full-Text PDF Open Access