title: The Effects of Short-Term Propofol and Dexmedetomidine on Lung Mechanics, Histology, and Biological Markers in Experimental Obesity.
abstract: BACKGROUND
  Administering anesthetics to the obese population requires caution because of a variety of reasons including possible interactions with the inflammatory process observed in obese patients. Propofol and dexmedetomidine have protective effects on pulmonary function and are widely used in short- and long-term sedation, particularly in intensive care unit settings in lean and obese subjects. However, the functional and biological effects of these drugs in obesity require further elucidation. In a model of diet-induced obesity, we compared the short-term effects of dexmedetomidine versus propofol on lung mechanics and histology, as well as biological markers of inflammation and oxidative stress modulation in obesity.
  
  
  METHODS
  Wistar rats (n = 56) were randomly fed a standard diet (lean) or experimental diet (obese) for 12 weeks. After this period, obese animals received sodium thiopental intraperitoneally and were randomly allocated into 4 subgroups: (1) nonventilated (n = 4) for molecular biology analysis only (control); (2) sodium thiopental (n = 8); (3) propofol (n = 8); and (4) dexmedetomidine (n = 8), which received continuous IV administration of the corresponding agents and were mechanically ventilated (tidal volume = 6 mL/kg body weight, fraction of inspired oxygen = 0.4, positive end-expiratory pressure = 3 cm H2O) for 1 hour.
  
  
  RESULTS
  Compared with lean animals, obese rats did not present increased body weight but had higher total body and trunk fat percentages, airway resistance, and interleukin-6 levels in the lung tissue (P = 0.02, P = 0.0027, and P = 0.01, respectively). In obese rats, propofol, but not dexmedetomidine, yielded increased airway resistance, bronchoconstriction index (P = 0.016, P = 0.02, respectively), tumor necrosis factor-α, and interleukin-6 levels, as well as lower levels of nuclear factor-erythroid 2-related factor-2 and glutathione peroxidase (P = 0.001, Bonferroni-corrected t test).
  
  
  CONCLUSIONS
  In this model of diet-induced obesity, a 1-hour propofol infusion yielded increased airway resistance, atelectasis, and lung inflammation, with depletion of antioxidative enzymes. However, unlike sodium thiopental and propofol, short-term infusion of dexmedetomidine had no impact on lung morphofunctional and biological variables.
authors.affiliation: From the *Laboratory of Pulmonary Investigation, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; †Department of Surgical and Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; ‡Faculty of Medicine, Laboratory of Experimental Surgery, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; §Laboratory of Molecular Endocrinology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; ‖Department of Surgical Sciences and Integrated Diagnostics, IRCCS AOU San Martino-IST, University of Genoa, Genoa, Italy; and ¶Division of Anesthesiology, Department of Surgery, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Luciana Boavista Barros
authors.initials: LB
authors.lastname: Heil
authors.forename: Cíntia L
authors.initials: CL
authors.lastname: Santos
authors.forename: Raquel S
authors.initials: RS
authors.lastname: Santos
authors.forename: Cynthia S
authors.initials: CS
authors.lastname: Samary
authors.forename: Vinicius C M
authors.initials: VC
authors.lastname: Cavalcanti
authors.forename: Mariana M P N
authors.initials: MM
authors.lastname: Araújo
authors.forename: Hananda
authors.initials: H
authors.lastname: Poggio
authors.forename: Lígia de A
authors.initials: Lde A
authors.lastname: Maia
authors.forename: Isis Hara
authors.initials: IH
authors.lastname: Trevenzoli
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Fatima C
authors.initials: FC
authors.lastname: Fernandes
authors.forename: Nivaldo R
authors.initials: NR
authors.lastname: Villela
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Silva
authors.forename: Patricia R M
authors.initials: PR
authors.lastname: Rocco
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D020927:Dexmedetomidine / Q000008:administration & dosage*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009765:Obesity / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D015742:Propofol / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial / Q000009:adverse effects; D015656:Respiratory Mechanics / Q000187:drug effects* / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D020927:Dexmedetomidine; D015742:Propofol