title: [Cardiocirculatory effects of intravenous anesthetic induction in an experimental model of acute hypovolemia].
abstract: OBJECTIVE
  To evaluate the cardiovascular effects of ketamine, midazolam, thiopentone and propofol in acutely hypovolemic pigs and to determine whether the association of ketamine and midazolam offers any advantage.
  
  
  METHODS
  Twenty-two Landrace-Large-White pigs. After monitoring was begun, acute hypovolemia was induced by means of rapid exsanguination of 30% of calculated volume. Hemodynamic variables were measured: a) at baseline; b) after exsanguination; c) 2 min after anesthetic induction; d) 10 min after anesthetic induction, and e) after reinfusion of the exsanguinated volume.
  
  
  RESULTS
  All pressures, cardiac output, cardiac index, and mixed venous oxygen saturation fell significantly with the induction of hypovolemia. Heart rate, systemic vascular resistances and arteriovenous oxygen differential increased. Ten min after anesthetic induction, heart rate in the midazolam group was significantly lower than in the ketamine-midazolam group. Arterial pressures decreased significantly after anesthetic induction with all drugs. The decrease in systolic arterial pressure was smaller in thiopenthal-anesthetized pigs than in pigs receiving either midazolam or propofol at the 10 min recording. The decrease in mean arterial and diastolic pressure after 10 min was smaller with thiopental than with any other drug. The decrease in mean arterial pressure was less in the thiopental and ketamine-midazolam groups than in the others after reinfusion. Diastolic arterial pressure at 10 min and after reinfusion had decreased less in the thiopental and ketamine-midazolam groups than in the propofol group. After anesthetic induction, the post-hypovolemic figures for cardiac output and cardiac index held steady or changes were slightly accentuated, with no statistically significant differences among the groups.
  
  
  CONCLUSIONS
  The intravenous anesthetics evaluated were detrimental to cardiovascular function in acute hypovolemic pigs. Low-dose thiopental and ketamine plus midazolam may be the anesthetics of choice in this setting. Propofol caused the greatest degree of hemodynamic instability.
authors.affiliation: Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital General Universitario de Valencia.
authors.forename: C L
authors.initials: CL
authors.lastname: Errando
authors.forename: J C
authors.initials: JC
authors.lastname: Valía
authors.forename: C
authors.initials: C
authors.lastname: Sifre
authors.forename: S
authors.initials: S
authors.lastname: Moliner
authors.forename: F
authors.initials: F
authors.lastname: Gil
authors.forename: O
authors.initials: O
authors.lastname: Gimeno
authors.forename: J M
authors.initials: JM
authors.lastname: Palanca
mesh_terms: D000208:Acute Disease; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous; D000818:Animals; D006439:Hemodynamics / Q000187:drug effects*; D007431:Intraoperative Complications / Q000188:drug therapy*; D012771:Shock, Hemorrhagic / Q000503:physiopathology*; D013552:Swine
chemical_list: D018686:Anesthetics, Intravenous
vernacular_title: Efectos cardiocirculatorios de la inducción anestésica intravenosa en un modelo experimental de hipovolemia aguda.