title: Effects of different concentrations of isoflurane pretreatment on respiratory mechanics, oxygenation and hemodynamics in LPS-induced acute respiratory distress syndrome model of juvenile piglets.
abstract: OBJECTIVE
  This study was prospectively designed to investigate the effects of different concentrations of isoflurane (ISO) pretreatment on respiratory mechanics, oxygenation, and hemodynamics in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) model of juvenile piglets.
  
  
  METHODS
  Twenty-four piglets (9-14 kg, 5-6 weeks old) were randomly assigned to four groups (n = 6): LPS group, which was injected with LPS (20 μg/kg) to induce ARDS; 0.5 ISO-LPS, 1.0 ISO-LPS, and 1.3 ISO-LPS groups, which were pretreated with 0.5, 1.0, and 1.3 minimum alveolar concentrations (MAC) ISO for 30 min before immediate LPS infusion, respectively. After establishment of ARDS, respiratory mechanism, oxygenation and hemodynamics parameters were measured at baseline, and 0, 1, 2, 3, and 4 hours after induction of ARDS.
  
  
  RESULTS
  After induction of ARDS, there were increases in alveolar-arterial oxygen difference (A-aDO2), oxygenation index (OI), mean airway pressure (MAP), dead space-to-tidal volume ratio, heart rate (HR), dP/dtmax, extravascular lung water index, pulmonary vascular permeability index, and PaCO2, and decreases in PaO2/FIO2, respiratory rate (RR), dynamic lung compliance (Cdyn), mean arterial blood pressure (MABP) and systemic vascular resistance (SVR) compared with baseline (P(time) < 0.05). Pretreatment with 1.0 and 1.3 MAC ISO alleviated changes in dP/dtmax and PaCO2 at ARDS 0-2 hours, SVR at 0-3 hours, PaO2/FIO2, RR, and MABP at 1-2 hours, HR at 2-3 hours, A-aDO2 at 3-4 hours, and OI at 4 hours (P(group) < 0.05).
  
  
  CONCLUSIONS
  Pretreatment with 1.0 and 1.3 MAC ISO had protective effects on respiratory mechanics, oxygenation, and hemodynamics in piglets with LPS-induced ARDS.
authors: a Department of Anesthesiology , The Eye Ear Nose and Throat Hospital, Fudan University , Shanghai , China.
authors: Haibin
authors: H
authors: Fu
authors: b Department of Anesthesiology , Zhongshan Hospital, Fudan University , Shanghai , China.
authors: Minli
authors: M
authors: Sun
authors: c Department of Anesthesiology , Shanghai Cancer Center, Fudan University , Shanghai , China.
authors: Changhong
authors: C
authors: Miao
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis / Q000379:methods; D015633:Extravascular Lung Water / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D007530:Isoflurane / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008170:Lung Compliance / Q000187:drug effects / Q000502:physiology; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D011659:Pulmonary Gas Exchange / Q000187:drug effects / Q000502:physiology; D012119:Respiration / Q000187:drug effects; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000187:drug effects* / Q000502:physiology; D013552:Swine
chemical_list: D008070:Lipopolysaccharides; D007530:Isoflurane; D010100:Oxygen
keywords: ARDS; acute respiratory distress syndrome; endotoxin; isoflurane pretreatment; lipopolysaccharide; piglet