Analgesic and respiratory effects of epidural sufentanil in patients following thoracotomy.

Immediately following thoracotomy, 22 patients were entered into a randomized, double blind study comparing the effects of three lumbar epidural doses of sufentanil on postoperative pain and respiratory pattern. Patients were given either 30 micrograms (group I), 50 micrograms (group II), or 75 micrograms (group III) of epidural sufentanil in 20 ml N saline. Repeat doses were given on request for the 24-h study period. Linear analogue pain score (PS), heart rate (HR), and mean arterial pressure (MAP) were measured at 15-min intervals after each dose. Respiratory depression was assessed by the presence of: 1) slow respiratory rate (SRR--less than 10 breaths per minute for greater than 5 min), 2) apnea (AP--cessation of tidal ventilation for greater than 15 s), and 3) increased PaCO2 in arterial blood gases (ABG) drawn at regular intervals. SRR and AP were measured using respiratory inductive plethysmography (RIP). A further group of ten patients (group IV) underwent preoperative RIP monitoring during sleep and in the absence of any drug. Maximum analgesia was achieved within 15 min after a dose of sufentanil for all groups. Analgesia was not significantly prolonged by increasing the dose of sufentanil. SRR occurred in all four groups (group I: 2/9; group II: 2/6; group III: 7/7; group IV: 2/10 P less than 0.05 I, IV:II, I, IV:III, II:III). The number of episodes of SRR/hr was highest in group II (group I: 0.6 +/- 0.8, group II: 4.12 +/- 0.6, group III: 1.8 +/- 2.0, group IV: 0.5 +/- 0.2) (NS).(ABSTRACT TRUNCATED AT 250 WORDS)