title: [Anesthetic induction after treated hemorrhagic shock: experimental study comparing ketamine and etomidate.].
abstract: OBJECTIVE
  Bleeding causing hemorrhagic shock usually requires surgical treatment under general anesthesia. Anesthetic drugs may further compromise hemodynamics. The objective was to compare the hemodynamic effects of ketamine and etomidate during anesthetic induction in dogs submitted to an experimental model of hemorrhagic shock and resuscitation.
  
  
  METHODS
  Thirty-two mongrel dogs were submitted to a pressure-controlled hemorrhagic shock, resuscitation and anesthetic induction model. After achieving the target pressure of 40 mmHg, they were randomly assigned in two groups according to the resuscitation fluid to be used: NaCl 0.9% (32 mL.kg-1) and NaCl 7.5% (4 mL.kg-1). After volume infusion, these groups were reassigned according to anesthetic drug used: GI) NaCl 0.9% and ketamine; GII) NaCl 7.5% and ketamine; GIII) NaCl 0.9% and etomidate; and GIV) NaCl 7.5% and etomidate. Hemodynamic measurements were obtained at five moments: (M0) baseline; (M1) after bleeding to shock; (M2) after volume expansion; (M3) 5 minutes after anesthetic induction; (M4) 15 minutes after anesthetic induction. Statistical analysis was performed using Student t test and two way ANOVA. Value of p lower than 0.05, was considered significant.
  
  
  RESULTS
  After shock, both solutions restored hemodynamics to baseline values. Independently of anesthetic agent or expansion solution used, mean arterial pressure remained unaltered for all groups after induction. Central venous pressure, heart rate, pulmonary capillary wedge pressure and pulmonary vascular resistance index increased significantly after ketamine infusion. Cardiac index, systemic vascular resistance index and oxygen transport variables remained stable in all groups.
  
  
  CONCLUSIONS
  Etomidate or ketamine were able to maintain hemodynamic stability in dogs undergoing severe hemorrhagic shock treated with NaCl 0.9% or NaCl 7.5%.
authors.affiliation: Serviço de Anestesiologia, InCor, FM, USP.
authors.forename: Adilson O
authors.initials: AO
authors.lastname: Fraga
authors.forename: Luiz Marcelo Sá
authors.initials: LM
authors.lastname: Malbouisson
authors.forename: Ricardo
authors.initials: R
authors.lastname: Prist
authors.forename: Maurício
authors.initials: M
authors.lastname: Rocha E Silva
authors.forename: José Otávio Costa
authors.initials: JO
authors.lastname: Auler Júnior