Continuous interpleural infusion of bupivacaine for postoperative analgesia after surgery with flank incisions: a double-blind comparison of 0.25% and 0.5% solutions.

Postoperative analgesia, as assessed by visual analogue scale scores (0-10) and patient-controlled analgesia morphine requirements, pulmonary function (forced vital capacity and forced expiratory volume in 1 s), and plasma bupivacaine concentrations were studied in patients receiving interpleural blockade with bupivacaine after surgery with a flank incision. Two groups of 10 patients received either 0.5% or 0.25% bupivacaine, both with epinephrine (5 micrograms/mL). Pain relief was initiated when patients had visual analogue scale scores greater than or equal to 4. Patients received 21 mL of bupivacaine 0.25% or 0.5% in a double-blind fashion. One hour later, a continuous infusion of 5 mL/h of the study solution was started. At the same time, patient-controlled analgesia became accessible to the patients. The onset time of pain relief and the area under the visual analogue scale score-time curves over the first 8 h were similar in both groups. Patient-controlled analgesia morphine use was also similar in the 0.25% (21.3 +/- 14.6 mg) and 0.5% (21.0 +/- 16.0 mg) groups (mean +/- SD). In both groups, forced vital capacity and forced expiratory volume in 1 s improved significantly within 60 min (P less than 0.05). Peak plasma concentrations (Cmax) and the area under the plasma concentration-time curve (AUC) over 24 h were higher (P less than 0.001) in the 0.5% group (Cmax, 1.47 +/- 0.37 micrograms/mL; AUC, 1511 +/- 323 micrograms.mL-1.min) than those in the 0.25% group (Cmax, 0.55 +/- 0.22 micrograms/mL; AUC, 680 +/- 118 micrograms.mL-1.min) (mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)

Uptake of sufentanil, alfentanil and morphine in the lungs of patients about to undergo coronary artery surgery.

We have studied the pulmonary extraction and retention of sufentanil, alfentanil and morphine using a double indicator technique in 30 patients undergoing elective aortocoronary bypass surgery. Patients were allocated to three groups (10 each) to receive sufentanil 43 micrograms, alfentanil 672 micrograms or morphine 1887 micrograms, mixed with indocyanine green as indicator. After sufentanil, mean peak extraction was 93.7% (95% confidence interval 87.1-100.4%) and release occurred after 16.1 (13.8-18.4) s; first-pass retention was 61.1 (51.3-70.9)%. After alfentanil, peak extraction was 67.4 (42.7-92.0)% and release occurred after 9.9 (8.5-11.3) s; first-pass retention was 10.1 (3.5-16.7)%. After morphine, peak extraction was 58.3 (44.4-72.2)% and release occurred after 7.2 (4.4-10.1) s; first-pass retention was 7.1 (-4.7-19.9)%. Both peak extraction and first-pass retention were significantly greater after sufentanil. There was no significant difference in the peak extraction and first-pass retention between alfentanil and morphine.