Near-Infrared Spectroscopy for Evaluation of Cerebral Autoregulation During Orthotopic Liver Transplantation

Abstract

We find that NIRS is a ready available non-invasive technology for evaluation of cerebral autoregulation in patients undergoing orthotopic liver transplantation.

Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair: relation to end-tidal CO2 tension

“…Also it is important that NIRS detects the lower limit for cerebral autoregulation [5,6] and thereby allows for interventions aimed to maintain S c O 2 and thereby improve postoperative outcome [7][8][9][10][11][12]. The CO 2 -reactivity, however, varies among patient groups, e.g.…”

Influence of Changes in Blood Pressure on Cerebral Perfusion and Oxygenation

“…11 Thus, despite the extensive use and reference to static CA, quantification of CA has not been clearly identified for human experimentation. In addition, near infrared spectroscopy (NIRS) for the monitoring of local cerebral oxygenation has been used in the clinical assessment of CA, 12 in addition to the assessment of cerebral ischemia. 13 The use of NIRS is attractive because it is noninvasive, does not require frequent calibration, is robust, and, unlike transcranial Doppler, the problem of a constant and precise location of the probes is less of an issue.…”

Cardiovascular Monitoring and Substitution of the Blood Volume During Liver Transplantation

“…Cerebral perfusion may be followed by transcranial Doppler (TCD) derived middle cerebral artery mean blood velocity (MCA V mean ) (Pott et al, 1995) and evaluation of cerebral tissue flow by clearance of 133 Xe has been carried out during OLT (Larsen et al, 1999). However, it remains that NIRS is, by far the most feasible method for routine monitoring of cerebral perfusion during surgery (Nissen et al, 2009a;Steiner et al, 2009). NIRS reflects changes in brain capillary saturation and mitochondrial oxygen tension in response to manipulation of the inspired oxygen and CO 2 tensions (Rasmussen et al, 2007) although a potential influence of skin blood flow needs to be considered (Sato et al, 2011).…”

“…A given MAP therefore does not guarantee that cerebral perfusion is secured leading to the conclusion that CBF or, more likely, S c O 2 should be monitored during the operation (Nissen et al, 2009a). Also it is to be considered that administration of phenylephrine in case of a low blood pressure, in an attempt to increase blood pressure to above what is might present the lower limit of cerebral autoregulation, is associated with a decrease rather than with the probably intended increase in S c O 2 (Nissen et al, 2010).…”

“…Despite these limitations in the use of HR and MAP to detect deviations in CBV, the capability to balance CBV is of importance for tissue perfusion and oxygenation and notably for oxygenation of the brain (S c O 2 ) (Nissen et al, 2009a), indicating that advanced cardiovascular monitoring is required to secure the well-being of the patient (Yao et al, 2004;Bundgaard-Nielsen et al, 2007a;Murkin et al, 2007) In order to maintain CBV during surgery, it is important that normovolaemia is defined. For supine humans the heart operates on the upper flat part of the Frank-Starling curve (Harms et al, 2003) and to establish and to maintain a maximal resting stroke volume for the heart (or CO) secures that the patient remains normovolaemic during the operation and that fluid administration strategy reduces postoperative complications to an extent that affects the hospital stay (Bundgaard-Nielsen et al, 2007a).…”