title: Intraoperative lactate measurements are not predictive of death in high risk surgical patients.
abstract: OBJECTIVE
  An increased lactate level is classically considered a marker for poorer prognosis, however little information is available on intraoperative lactate's kinetics and its connection with prognosis. This study aimed to evaluate the time when perioperative lactate is most relevant for prognosis.
  
  
  METHODS
  This was an observational prospective study conducted in a tertiary hospital. Patients with requested intensive care unit postoperative stay, aged > 18 years, undergoing major surgery were included. Palliative surgery patients and those with heart and/or severe liver failure were excluded. Arterial lactate levels were measured immediately before the surgery start (T0), after anesthesia induction (T1), 3 hours after the surgery start (T2), intensive care unit admission (T3) and 6 hours after the intensive care unit admission (T4).
  
  
  RESULTS
  Sixty seven patients were included. The mean lactate values for the patients' T0, T1, T2 and T4 were 1.5 ± 0.8 mmol/L, 1.5 ± 0.7 mmol/L, 1.8 ± 1.2 mmol/L, 2.7 ± 1.7 mmol/L and 3.1 ± 2.0 mmol/L, respectively. The hospital mortality rate was 25.8%, and surviving and non-surviving patients lactate values in the intensive care unit were 2.5 ± 1. and 4.8 ± 2.8 mmol/L (P < 0.0001), respectively. The other times measurements showed no statistically significant differences between the groups.
  
  
  CONCLUSIONS
  In surgical patients, intraoperative arterial lactate levels failed to show a predictive value; however during the postoperative period, this assessment was shown to be useful for hospital mortality prediction.
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: João Manoel
authors.initials: JM
authors.lastname: Silva Junior
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Amanda Maria Ribas Rosa
authors.initials: AM
authors.lastname: Oliveira
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Bruno Ricciardi
authors.initials: BR
authors.lastname: Silveira
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Ulisses Pinto
authors.initials: UP
authors.lastname: Ferreira
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Rodrigo Natal
authors.initials: RN
authors.lastname: Albretht
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Tiago Bertacini
authors.initials: TB
authors.lastname: Gonzaga
authors.affiliation: Hospital do Servidor Público Estadual Francisco Morato de Oliveira, São Paulo, SP, Brasil.
authors.forename: Ederlon
authors.initials: E
authors.lastname: Rezende