RESUMEN
The effects of anesthetic gases [N2O/O2 and Halothane of Enflurane] and muscle relaxants [Pancronium or Atracurium] on Lower Esophageal Sphincter Pressure [LESP] were studied in 20 ASA I or II patients, by a perfused 8-channel probe constructing an imaginary 3-dimensional image of the asymmetric lower esophageal sphincter [LES]. The inhalation of N2O/O2 alone or in combination with 2 MAC Halothane or Enflurane resulted in a highly significant pressure drop [P <0.05] at LES. After Pancronium 0.1 mg/kg IV, there was a significant increase in LESP from control values. The findings of this pilot study suggest that pancuronium may be beneficial in induction than atracurium and that silent regurgitation is always a risk during maintenance of anesthesia because of the complex pharmacological actions of N2O/O2, Halothane or Enflurane upon the LESP