title: Associated factors to empyema in post-traumatic hemotorax.
abstract: OBJECTIVE
  to analyze the associated factors with empyema in patients with post-traumatic retained hemothorax.
  
  
  METHODS
  prospective observational study. Data were collected in patients undergoing PD during emergency duty. Variables analyzed were age, sex, mechanism of injury, side of the chest injury, intrathoracic complications of RH, laparotomy, specific injuries, rib fractures, trauma scores, days to diagnosis, diagnostic method of RH, primary indication of PD, initial volume drained, length of the first tube removal, surgical procedure. Cumulative incidence of empyema, pneumonia and pulmonary contusion and the proportion of patients with empyema or without empyema in each category of each variable analyzed were obtained.
  
  
  RESULTS
  the cumulative incidence of PD among trauma patients was 1.83% and the RH among those with PD was 10.63%. There were 20 cases of empyema (32.8%). Most were male in the age from 20 to 29, victims of injury by firearm on the left side of the thorax. The incidence of empyema in patients with injury by firearms was lower compared to those with stab wound or blunt trauma; higher among those with drained volume between 300 and 599 ml. The median hospital lenght of stay was higher among those with empyema.
  
  
  CONCLUSIONS
  the incidence of PD was 1.83% and RH was 10.63%, these results are consistent with the low severity of the patients involved in this study and consistent with the literature. The incidence of empyema proved to be negatively associated with the occurrence of injury by firearms and positively associated with a drained volume between 300 and 599 ml, compared with lower or higher volumes.
authors.affiliation: Hospital Risoleta Tolentino Neves, Fundep/UFMG, Brazil.
authors.forename: Mario
authors.initials: M
authors.lastname: Pastore Neto
authors.affiliation: Departamento de Cirurgia, Faculdade de Medicina, UFMG, Brazil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Resende
authors.affiliation: Departamento de Medicina Preventiva e Social, Faculdade de Medicina, UFMG, Brazil.
authors.forename: Carla Jorge
authors.initials: CJ
authors.lastname: Machado
authors.affiliation: Hospital Risoleta Tolentino Neves, Fundep/UFMG, Brazil.
authors.forename: Emanuelle Maria Sávio
authors.initials: EM
authors.lastname: de Abreu
authors.affiliation: St. Michael's Hospital, Department of Surgery, University of Toronto, Canada.
authors.forename: João Baptista
authors.initials: JB
authors.lastname: de Rezende Neto
authors.affiliation: Departamento de Cirurgia, Faculdade de Medicina, UFMG, Brazil.
authors.forename: Marcelo Dias
authors.initials: MD
authors.lastname: Sanches
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004653:Empyema / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006491:Hemothorax / Q000150:complications* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013898:Thoracic Injuries / Q000150:complications*; D055815:Young Adult