title: Continuous measurement of cardiac output with the electrical velocimetry method in patients under spinal anesthesia for cesarean delivery.
abstract: In this study, we aimed to continuously measure cardiac output (CO) with the electrical velocimetry (EV) method and characterize the hemodynamic profile of patients undergoing spinal anesthesia for elective cesarean delivery (CD), and to discuss the potential benefit of using real time CO monitoring to guide patient management. Forty-two patients scheduled for elective CD under spinal anesthesia were enrolled in this observational study. A non-invasive CO monitor incorporating the electrical velocimetry algorithm, ICON(®) (Cardiotronic(®), La Jolla, California, USA), was used to measure CO and stroke volume (SV) continuously. Peripheral venous pressure was measured intermittently at pre-defined time points. Systemic vascular resistance was calculated retrospectively after completion of the study. Hemodynamic changes at pre-defined time points and caused by phenylephrine administration were analyzed. Hypotension (MAP reduction more than 20% from baseline values) occurred in 71.1% of patients after spinal anesthesia, while the coinstantaneous CO was increased ≥20% from baseline in the majority of patients (76.3%) at the same time. Significant increase in CO took place at 3-2 min before the administration of phenylephrine bolus. Treatment of hypotension with phenylephrine was associated with significant decrease in CO. Continuous CO monitoring with EV enables clinicians to determine CO and SV changes prior to onset of hypotension and to better understand patients' hemodynamics. It is an important addition to the current monitoring. The benefit of routinely using this technique remains to be determined in term of the patient outcomes.
authors.affiliation: Anesthesia and Operation Center, Chinese PLA General Hospital, Beijing, China.|Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: May C M
authors.initials: MC
authors.lastname: Pian-Smith
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Leffert
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: Rebecca D
authors.initials: RD
authors.lastname: Minehart
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Torri
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Coté
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA.|Department of Respiratory Care, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kacmarek
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Jackson 422, Boston, MA, 02114, USA. yjiang@partners.org.
authors.forename: Yandong
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000775:Anesthesia, Spinal / Q000379:methods*; D002302:Cardiac Output; D002307:Cardiography, Impedance / Q000379:methods*; D002585:Cesarean Section / Q000379:methods*; D005260:Female; D006334:Heart Function Tests / Q000379:methods*; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Cardiac output; Cesarean delivery; Electrical velocimetry; Obstetric; Spinal anesthesia