title: The Role of Elevated Lactate as a Risk Factor for Pulmonary Morbidity After Early Fixation of Femoral Shaft Fractures.
abstract: OBJECTIVE
  To evaluate lactate levels before reamed intramedullary nailing (IMN) of femur fractures treated with early fixation.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Three academic, tertiary care trauma centers.
  
  
  METHODS
  Age ≥18 years, injury severity score ≥17, admission lactate ≥ 2.5 mmol/L, elevated preoperative lactate = preoperative lactate ≥ 2.5 mmol/L.
  
  
  METHODS
  Reamed IMN of femur fracture within 24 hours.
  
  
  METHODS
  Total duration of mechanical ventilation, pulmonary complications (PC) = duration of mechanical ventilation ≥5 days.
  
  
  RESULTS
  Four hundred and fourteen patients identified; 294/414 (71.0%) with admission lactate ≥ 2.5 mmol/L. No difference in PC among the groups (86/294, 29.3% vs. 28/120, 23.3%; P = 0.22). Median admission lactate: 3.7 (interquartile range: 3.0-4.6); median preoperative lactate: 2.8 (interquartile range: 1.9-3.5). 184/294 (62.6%) demonstrated an elevated preoperative lactate (≥ 2.5 mmol/L) before fracture fixation. No difference in elevated preoperative lactate and vent days (4.8 ± 9.9 vs. 3.9 ± 6.0, P = 0.41) or PC (50/86, 58.1% vs. 134/208, 64.4%; P = 0.31). There was no difference in PC when preoperative lactate was considered separately for a lactate ≥3.0 (34/123, 27.6% vs. 52/171, 30.4%; P = 0.61), ≥3.5 (21/79, 26.6% vs. 65/215, 30.2%; P = 0.54), or ≥4.0 (14/50, 28.0% vs. 72/244, 29.5%; P = 0.83). Multivariable linear regression modeling demonstrated that admission lactate [coefficient of variation: 0.84, standard error: 0.33, 95% confidence interval (CI): 0.20-1.49] was correlated with duration of mechanical ventilation, after adjusting for emergency department Glasgow Coma Scale, age, chest Abbreviated Injury Scale (AIS) score, abdominal AIS, and admission glucose. Logistic regression demonstrated admission lactate was also significantly associated with PC (odds ratio: 1.26, 95% CI: 1.03-1.53) after controlling for age, admission Glasgow Coma Scale, chest AIS, abdominal AIS, admission pulse and admission glucose; preoperative lactate was not a risk factor (odds ratio: 0.84, 95% CI: 0.65-1.09) for PC.
  
  
  CONCLUSIONS
  Median admission lactate of 3.7 mmol/L was associated with duration of mechanical ventilation ≥5 days, whereas median preoperative lactate of 2.8 mmol/L was not, when multisystem trauma patients with a femoral shaft fracture were treated with reamed IMN within 24 hours after admission.
  
  
  METHODS
  Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: *Division of Trauma Anesthesiology, R Adams Cowley Shock Trauma Center, Baltimore, MD; †Department of Orthopaedics, R Adams Cowley Shock Trauma Center, Baltimore, MD; ‡Department of Orthopaedics, Carolinas Medical Center, Charlotte, NC; §Vanderbilt Orthopaedic Institute, Vanderbilt University School of Medicine, Nashville, TN; ‖Division of Trauma, Emergency Surgery, and Surgical Critical Care, Vanderbilt University Medical Center, Nashville, TN; and ¶Division of Orthopaedic Trauma, Vanderbilt Orthopaedic Institute, Nashville, TN.
authors.forename: Justin E
authors.initials: JE
authors.lastname: Richards
authors.forename: Paul E
authors.initials: PE
authors.lastname: Matuszewski
authors.forename: Sean M
authors.initials: SM
authors.lastname: Griffin
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Koehler
authors.forename: Oscar D
authors.initials: OD
authors.lastname: Guillamondegui
authors.forename: Robert V
authors.initials: RV
authors.lastname: OʼToole
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bosse
authors.forename: William T
authors.initials: WT
authors.lastname: Obremskey
authors.forename: Jason M
authors.initials: JM
authors.lastname: Evans
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005264:Femoral Fractures / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects* / Q000379:methods; D015600:Glasgow Coma Scale; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D007773:Lactates / Q000097:blood*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D015999:Multivariate Analysis; D011300:Preoperative Care / Q000379:methods; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D014193:Trauma Centers; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007773:Lactates