Bilateral intrapleural regional analgesia for postoperative pain control: a dose-finding study

Postoperative pain management for major abdominal or thoracoabdominal procedures requires bilateral multisegmental intercostal nerve blocks or epidural analgesia. This study was undertaken to examine the possible role of bilateral intrapleural regional analgesia (BIRA) and to select the proper dose for this new technique. Bilateral intrapleural catheters were inserted after surgery, using a Mancao dual-cannula system. Bupivacaine with epinephrine 1/200,000 (BE) was administered in each side as 20 mL of 0.5% in three patients. When this dose was found to be ineffective, 30 mL of 0.75% BE was administered in five patients; however, two patients complained of tinnitus and visual disturbances. Subsequently, 20 mL of 0.75% BE was used in five patients and was found to be satisfactory. Thirteen additional patients received the latter dose. Arterial blood levels of bupivacaine were determined at 15, 30, 60, and 120 minutes. The group of 18 patients (group I) who received 20 mL of 0.75% BE bilaterally were compared with a second group (group II) of 16 patients undergoing similar surgery who received only parenteral narcotics for pain management. BIRA was considered effective when patients denied pain or discomfort and when narcotics were not required in the postanesthesia recovery unit. Patients in groups I and II received narcotic medication whenever they felt pain or discomfort. The duration of BIRA was considered to be from the injection of the drug until the time a narcotic was administered to the patient. Demographic variables, changes in BP and heart rate after surgery, frequency of narcotic administration during the first four postoperative days, and postoperative hospital stay were compared in groups I and II.(ABSTRACT TRUNCATED AT 250 WORDS)