title: Effects of mechanical ventilation on release of cytokines into systemic circulation in patients with normal pulmonary function.
abstract: BACKGROUND
  Mechanical ventilation with high tidal volumes (V(T)) in contrast to mechanical ventilation with low V(T) has been shown to increase plasma levels of proinflammatory and antiinflammatory mediators in patients with acute lung injury. The authors hypothesized that, in patients without previous lung injury, a conventional potentially injurious ventilatory strategy with high V(T) and zero end-expiratory pressure (ZEEP) will not cause a cytokine release into systemic circulation.
  
  
  METHODS
  A total of 39 patients with American Society of Anesthesiologists physical status I-II and without signs of systemic infection scheduled for elective surgery with general anesthesia were randomized to receive mechanical ventilation with either (1) V(T) = 15 ml/kg ideal body weight on ZEEP, (2) V(T) = 6 ml/kg ideal body weight on ZEEP, or (3) V(T) = 6 ml/kg ideal body weight on positive end-expiratory pressure of 10 cm H2O. Plasma levels of proinflammatory and antiinflammatory mediators tumor necrosis factor, interleukin (IL)-6, IL-10, and IL-1 receptor antagonist were determined before and 1 h after the initiation of mechanical ventilation.
  
  
  RESULTS
  Plasma levels of all cytokines remained low in all settings. IL-6, tumor necrosis factor, and IL-1 receptor antagonist did not change significantly after 1 h of mechanical ventilation. IL-10 was below the detection limit (10 pg/ml) in 35 of 39 patients. There were no differences between groups.
  
  
  CONCLUSIONS
  Initiation of mechanical ventilation for 1 h in patients without previous lung injury caused no consistent changes in plasma levels of studied mediators. Mechanical ventilation with high V(T) on ZEEP did not result in higher cytokine levels compared with lung-protective ventilatory strategies. Previous lunge damage seems to be mandatory to cause an increase in plasma cytokines after 1 h of high V(T) mechanical ventilation.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University of Bonn, Germany. hwrigge@uni-bonn.de
authors.forename: H
authors.initials: H
authors.lastname: Wrigge
authors.forename: J
authors.initials: J
authors.lastname: Zinserling
authors.forename: F
authors.initials: F
authors.lastname: Stüber
authors.forename: T
authors.initials: T
authors.lastname: von Spiegel
authors.forename: R
authors.initials: R
authors.lastname: Hering
authors.forename: S
authors.initials: S
authors.lastname: Wetegrove
authors.forename: A
authors.initials: A
authors.lastname: Hoeft
authors.forename: C
authors.initials: C
authors.lastname: Putensen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D002245:Carbon Dioxide; D016207:Cytokines / Q000097:blood*; D005260:Female; D006612:High-Frequency Ventilation / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011175:Positive-Pressure Respiration / Q000009:adverse effects; D013997:Time Factors
chemical_list: D015415:Biomarkers; D016207:Cytokines; D002245:Carbon Dioxide