title: The use of the oesophageal Doppler in perioperative medicine: new opportunities in research and clinical practice.
abstract: The oesophageal Doppler (OD) is a minimally invasive haemodynamic monitor used in the surgical theatre and the ICU. Using the OD, goal-directed therapy (GDT) has been shown to reduce perioperative complications in high-risk surgical patients. However, most GDT protocols currently in use are limited to stroke volume optimisation. In the present manuscript, we examine the conceptual models behind new OD-based measurements. These would provide the clinician with a comprehensive view of haemodynamic pathophysiology; including pre-load, contractility, and afterload. Specifically, volume status could be estimated using mean systemic filling pressure (MSFP), the pressure to which all intravascular pressures equilibrate during asystole. Using the OD, MSFP could be readily estimated by simultaneous measurements of aortic blood flow and arterial pressure with sequential manoeuvres of increasing airway pressure. This would result in subsequent reductions in cardiac output and arterial pressure and would allow for a linear extrapolation of a static MSFP value to a "zero flow" state. In addition, we also demonstrate that EF is proportional to mean blood flow velocity measured in the descending thoracic aorta with the OD. Furthermore, OD-derived indexes of blood flow velocity and acceleration, as well as force and kinetic energy, can be derived and used for continuous assessment of cardiac contractility at the bedside. Using OD-derived parameters, the different components of afterload: inertia, resistance and elastance, could also be individually determined. The integration of these additional haemodynamic parameters could assist the clinician in optimising and individualising haemodynamic performance in unstable patients.
authors: Department of Anaesthesiology, Pharmacology, and Intensive Care, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland. bernardo.bollenpinto@hcuge.ch.
authors: Bernardo Bollen
authors: BB
authors: Pinto
authors: Department of Anaesthesiology, Rutgers New Jersey Medical School, 185 South Orange Avenue, Newark, NJ, 07103, USA.|Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ, 07030-5991, USA.
authors: Glen
authors: G
authors: Atlas
authors: Department of Anaesthesiology, Academic Medical Centre, Meibergdreef 9, 1005 AZ, Amsterdam, The Netherlands.
authors: Bart F
authors: BF
authors: Geerts
authors: Department of Anaesthesiology, Pharmacology, and Intensive Care, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland.
authors: Karim
authors: K
authors: Bendjelid
mesh_terms: D001011:Aorta / Q000502:physiology; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D002302:Cardiac Output / Q000502:physiology; D003422:Critical Care; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D004947:Esophagus / Q000000981:diagnostic imaging*; D005440:Fluid Therapy; D006439:Hemodynamics; D006801:Humans; D007362:Intensive Care Units; D007700:Kinetics; D009200:Myocardial Contraction; D059035:Perioperative Period; D011312:Pressure; D013318:Stroke Volume; D018608:Ultrasonography, Doppler; D016277:Ventricular Function, Left
keywords: Doppler technique; Haemodynamic monitoring; Intensive care; Perioperative