Local anesthesia for pain relief after surgery

Postoperative pain is a common problem in spite of increased awareness among patients and healthcare professionals. The prevailing practice is still to administer opiates, which have a good painrelieving potential but opiates also have a number of negative sideffects. In this Thesis 1 have analysed the use of local anesthetics in various forms as an alternate means of pain relief after surgery. Paper I: Twentyone patients operated with an open cholecystectomy received an intrapleural catheter for administration of bupivacaine-adrenaline in various dose regimens. Pain relief and ventilatory parameters were recorded before and after administration. Plasma concentration of bupivacaine was assessed. A double-blind comparison was made in six of the patients. Five patients received an injection of local anesthesia with contrast to determine the distribution of the fluid within the pleura.The intrapleural treatment resulted in an effective pain relieving effect with an improved pulmonary function. The local anesthetic was distributed dorsally in the pleura from the base to the apex. No patient in the placebo group experienced pain relief or improved lungfunction, while the patients in the treatmentgroup were improved. Paper II: Twenty patients operated with open cholecystectomy received an intrapleural catheter for postoperative painrelief. The studied parameters were: analgesic effect (n=20), temperature and pain sense (n7=20), cutaneous bloodflow (n=9) and phrenic nerve stimulation (n=4). All patients reported reduced pain scores after treatment with 20 nil 0.25% bupivacaine, eleven patients had a loss of their temperature sense on the right side and of these ten also lost their pain sense after treatment, but all had reduced VAS scores. A sligh t increase in blood flow was recorded without difference between the sides, the phrenic nerve was not affected by the local anesthetic. Paper III: Twenty males undergoing inguinal hernia repair were subjected to treatment with infiltration of ropivacaine postoperatively. Ten patients received 300 mg and ten 375 mg in a double blind design. VAS scores and consumption of additional anIgesics were followed. Plasma concentrations were determined as well as blood samples and a close monitoring of adverse events was instituted. Both groups reported similar reduction of VAS scores and both groups required the same amount of additional analgesics. Plasma concentrations of ropivacaine were well below the estimated toxic levels a