INTERCOSTAL NERVE BLOCK FOR LUMPECTOMY - SUPERIOR POSTOPERATIVE PAIN RELIEF WITH BUPIVACAINE

Study Objectives: To investigate whether equipotent doses of lidocaine and bupivacaine were equally effective for intercostal nerve blockade (ICNB) and whether a lower amount of lidocaine would be comparably ef fective. To see whether plasma levels of lidocaine with and without ep inephrine and of plain bupivacaine would reach toxic ranges. Finally, to evaluate the duration of postoperative analgesia following general anesthesia and regional anesthesia with two different local anesthetic s. Design: Randomized, double-blind study, with central group administ ered general anesthesia. Setting: Gynecologic operating room of a univ ersity hospital. Patients: 48 adult ASA physical status I and II other wise healthy patients undergoing lumpectomy. Interventions: 36 patient s received ICNB of T-3-T-6 unilaterally using either 4 ml/ segment of 1.5% lidocaine with epinephrine 3.75 mu g/ml (n = 10, Group A), 4 ml/ segment of 2% lidocaine with epinephrine 5 mu g/ml (n = 13 Group B), o r 4 ml/segment of plain 0.5% bupivacaine (n = 13, Group C). The contro l group consisted of 12 patients (Group D) who received a general anes thetic using propofol, alfentanil, and nitrous oxide in oxygen for ind uction and maintenance of anesthesia. Measurements and Main Results: I n all three ICNB groups, the highest plasma concentrations were reache d after 5 to 10 minutes following ICNB-i.e., a lidocaine plasma level of 2.77 +/- 0.5 mu g/ml (mean +/- SEM) in Group A, a lidocaine plasma level of 2.78 +/- 0.2 mu g/ml in Group B, and a bupivacaine plasma lev el of 1.44 +/- 0.2 mu g/ml in Group C. There were no significant diffe rences in plasma levels between 1.5% lidocaine and 2 % lidocaine. For the first 90 minutes after surgery, higher postoperative pain scores w ere found in the control group than in the ICNB groups. Notably longer -lasting postoperative pain relief was achieved with plain bupivacaine . The number of women requiring postoperative analgesic medication, th e time of first request, and the total amount of analgesic drugs admin istered during the 24 hours postoperatively were significantly lower i n the regional anesthesia groups than in the general anesthesia group (p<005). Conclusions: ICNB is an alternative to general anesthesia for female breast surgery. Both lidocaine with epinephrine and plain bupi vacaine in the doses used did not raise venous plasma concentrations t o levels considered potentially toxic. With respect to duration of pos toperative pain relief and analgesic drug request, the local anestheti cs (in particular bupivacaine) were found to be superior to general an esthesia.