• Luciana Boavista Barros Heil, Cíntia L Santos, Raquel S Santos, Cynthia S Samary, Vinicius C M Cavalcanti, Mariana M P N Araújo, Hananda Poggio, Lígia de A Maia, Isis Hara Trevenzoli, Paolo Pelosi, Fatima C Fernandes, Nivaldo R Villela, Pedro L Silva, and Patricia R M Rocco.
• 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.
• Anesth. Analg. 2016 Apr 1; 122 (4): 1015-23.

BackgroundAdministering 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.MethodsWistar 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.ResultsCompared 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).ConclusionsIn 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.

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