A survey of combined epidural-propofol anesthesia with noninvasive positive pressure ventilation as a minimally invasive anesthetic protocol.

Background: Combined epidural-propofol anesthesia with use of noninvasive positive pressure ventilation (NPPV) via the nose has been used routinely in our operating theaters. The purpose of this report was to present a survey of this anesthesia.

Material/methods: 265 adult patients undergoing lower extremity or lower abdominal gynecological surgery during 1999 were examined. After epidural anesthesia, patients were given propofol infusion. NPPV was applied with an inspiratory/expiratory positive airway pressure of 14/8 cm H2O, a respiratory rate of 10 breaths/min, and oxygen delivery into the nasal mask resulting in a concentration of 40% or an inspiratory oxygen fraction of 0.35. Epidural anesthesia was continuously applied after surgery for postoperative pain relief. Various data related to the surgery or anesthesia were evaluated both on the day of surgery and on postoperative day 1.

Results: Of 265 patients, 3 patients could not receive our anesthetic protocol. Of the residual 262 patients, no patients showed serious clinical problems during anesthesia, excluding for hypotension, which was observed in 31-56% patients and was treated with ephedrine injection. Patients informed us of good analgesia (98%), feelings (78%) and dreams (47%). On postoperative day 1, postoperative analgesia and mood conditions were satisfactory. There were no patients complaining of intraoperative awareness.

Conclusions: The principle of our anesthesia consists of epidural anesthesia, sole propofol infusion and noninvasive airway management, so as to provide an anesthetic technique with minimal invasiveness. Although airway maintenance by NPPV is not always suitable, our anesthesia is practicable for certain kinds of operations.