title: Noninvasive continuous cardiac output monitoring in perioperative and intensive care medicine.
abstract: The determination of blood flow, i.e. cardiac output, is an integral part of haemodynamic monitoring. This is a review on noninvasive continuous cardiac output monitoring in perioperative and intensive care medicine. We present the underlying principles and validation data of the following technologies: thoracic electrical bioimpedance, thoracic bioreactance, vascular unloading technique, pulse wave transit time, and radial artery applanation tonometry. According to clinical studies, these technologies are capable of providing cardiac output readings noninvasively and continuously. They, therefore, might prove to be innovative tools for the assessment of advanced haemodynamic variables at the bedside. However, for most technologies there are conflicting data regarding the measurement performance in comparison with reference methods for cardiac output assessment. In addition, each of the reviewed technology has its own limitations regarding applicability in the clinical setting. In validation studies comparing cardiac output measurements using these noninvasive technologies in comparison with a criterion standard method, it is crucial to correctly apply statistical methods for the assessment of a technology's accuracy, precision, and trending capability. Uniform definitions for 'clinically acceptable agreement' between innovative noninvasive cardiac output monitoring systems and criterion standard methods are currently missing. Further research must aim to further develop the different technologies for noninvasive continuous cardiac output determination with regard to signal recording, signal processing, and clinical applicability.
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg 20246, Germany bernd.saugel@gmx.de.
authors.forename: B
authors.initials: B
authors.lastname: Saugel
authors.affiliation: Anaesthesia and Intensive Care, St George's Hospital and Medical School, London SW17 0QT, UK.
authors.forename: M
authors.initials: M
authors.lastname: Cecconi
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg 20246, Germany.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wagner
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, Hamburg 20246, Germany.
authors.forename: D A
authors.initials: DA
authors.lastname: Reuter
mesh_terms: D002302:Cardiac Output; D003422:Critical Care; D017097:Electric Impedance; D006801:Humans; D008991:Monitoring, Physiologic; D019990:Perioperative Care; D063177:Pulse Wave Analysis; D017534:Radial Artery / Q000502:physiology
keywords: cardiac output; intensive care unit; monitoring, intraoperative