Ketamine Activates Breathing and Abolishes the Coupling between Loss of Consciousness and Upper Airway Dilator Muscle Dysfunction

• DOI: 10.1097/aln.0b013e31823d010a
• Publication Date: 2011-11-22T11:26:06Z
• Authors: Matthias Eikermann; Martina Grosse-Su...; Sebastian Zaremba; Mark E. Henry; Edward A. Bittner; Ulrike Hoffmann; Nancy L. Chamberlin
• Keywords: Genioglossus; Dilator

Procedural sedation is frequently performed in spontaneously breathing patients, but hypnotics and opioids decrease respiratory drive place the upper airway at risk for collapse.In a randomized, controlled, cross-over, pharmaco-physiologic study 12 rats, we conducted acute experiments to compare genioglossus electromyogram activity equianesthetic concentrations of ketamine, noncompetitive N-methyl-D-aspartate receptor antagonist that combines potent analgesic with hypnotic action effects, versus propofol. In 10 chronically instrumented rats resting plethysmograph, measured these variables as well electroencephalography during five conditions: quiet wakefulness, nonrapid-eye-movement sleep, rapid eye movement low-dose (60 mg/kg intraperitoneally) high-dose ketamine anesthesia (125 intraperitoneally).Ketamine was associated markedly increased (1.5 fivefold higher values electromyogram) compared sleep- propofol-induced unconsciousness. Plethysmography revealed stimulating effect: flow rate, duty-cycle (effective inspiratory time, 1.5-to-2-fold values). During wakefulness normal δ (f = 6.51, P 0.04) electroencephalogram power spectrum an independent predictor activity, indicating association between electroencephalographic determinants consciousness activity. Following administration, dissociated (P 0.9 relationship δ/θ electromyogram).Ketamine stimulant abolishes coupling loss-of-consciousness dilator muscle dysfunction wide dose-range. Ketamine propofol might help stabilize patency anesthesia.