title: The effects of varying volumes of crystalloid administration before cesarean delivery on maternal hemodynamics and colloid osmotic pressure.
abstract: The value of intravenous crystalloid administration in preventing spinal-induced hypotension in the parturient has recently been questioned. Also, the association between increasing crystalloid volume and decreasing postpartum colloid osmotic pressure (COP) raises concern regarding the risk of maternal and fetal pulmonary edema. To study the dose-response effect of varying amounts of crystalloid volume prior to spinal anesthesia, we measured maternal hemodynamic variables and maternal and fetal COP in three groups of healthy parturients receiving spinal anesthesia for elective cesarean delivery. Fifty-five parturients were randomized in a double-blind fashion to receive one of 10, 20, or 30 mL/kg of crystalloid volumes prior to induction of spinal anesthesia. Measurements included mean arterial blood pressure (MAP), cardiac index (CI), and systemic vascular resistance index (SVRI) recorded using noninvasive thoracic impedance monitoring until delivery. Maternal and neonatal COP were measured. All groups showed declines in MAP and SVRI from baseline at 5 min after spinal anesthesia, but the amount of decline did not differ among groups. Total ephedrine and additional intravenous (i.v.) fluid administered did not differ among groups. The 20- and 30- mL/kg groups showed a larger decline in maternal COP than the 10-mL/kg group; no differences in neonatal COP were seen with varying preload. We conclude that increasing the amount of i.v. crystalloid administered to 30 mL/kg in the healthy parturient does not significantly alter maternal hemodynamics or ephedrine requirements after spinal anesthesia and has no apparent benefit.
authors.affiliation: Department of Anesthesia, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Park
authors.forename: M A
authors.initials: MA
authors.lastname: Hauch
authors.forename: F
authors.initials: F
authors.lastname: Curlin
authors.forename: S
authors.initials: S
authors.lastname: Datta
authors.forename: A M
authors.initials: AM
authors.lastname: Bader
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002307:Cardiography, Impedance; D002585:Cesarean Section; D000077324:Crystalloid Solutions; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D004809:Ephedrine / Q000008:administration & dosage; D005260:Female; D005315:Fetal Diseases / Q000209:etiology; D006801:Humans; D007022:Hypotension / Q000517:prevention & control; D007231:Infant, Newborn; D007552:Isotonic Solutions; D008991:Monitoring, Physiologic; D009997:Osmotic Pressure; D010952:Plasma Substitutes / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D049590:Postpartum Period; D011247:Pregnancy; D011654:Pulmonary Edema / Q000209:etiology; D015532:Rehydration Solutions / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000008:administration & dosage
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D015532:Rehydration Solutions; D014662:Vasoconstrictor Agents; D004809:Ephedrine