INTERPLEURAL ANALGESIA WITH BUPIVACAINE FOLLOWING THORACOTOMY - INEFFECTIVE RESULTS OF A CONTROLLED-STUDY AND PHARMACOKINETICS

Study Objective: To evaluate intrapleural analgesia with bupivacaine f ollowing partial pulmonary resection and to determine pharmacokinetic parameters of bupivacaine with epinephrine. Design: Prospective, rando mized study. Setting: Thoracic surgical clinic of a university-affilia ted general hospital.Patients: Eighteen consecutive patients (13 men, 5 women) scheduled for pulmonary surgery by posterolateral thoracotomy . Interventions: Bupivacaine was administered through an intrapleural catheter as a bolus dose of either 40 ml of 0.25% bupivacaine with epi nephrine (0.5 mg per 100 ml of solution) (n = 10) or 20 ml of 0.5% bup ivacaine with epinephrine (0.5 mg per 100 ml of solution) (n = 8) up t o three times daily for a maximum time of 4 days. Measurements and Mai n Results: Subjective evaluation of pain was performed using the visua l analog scale (VAS) before and after each injection by response to sp ontaneous pain, coughing, deep breathing, and incision palpation. Maxi mum peak concentration (C Max) and maximum time to reach the peak conc entration (T Max) were assessed after the first and last injections. A lthough VAS pain score decreased significantly, pain relief was not su fficient. C Max and T Max after the first and last injections were not significantly different between the two groups. In each group, C Max after the last injection was significantly higher than after the first injection. Conclusions: Intrapleural analgesia conducted with 40 ml o f 0.25% bupivacaine with epinephrine or 20 ml of 0.5% bupivacaine with epinephrine was insufficient for pain, despite high plasma bupivacain e concentration.