Pre-emptive analgesia with ropivacaine in adult tonsillectomy

Aim of investigation: We examined whether a pre-emptive analgesic effect co uld be achieved with ropivacaine,which has less cardiovascular and central nervous system toxicity than bupivacaine, in adults undergoing tonsillectom y. Methods: The study was carried out in 80 patients in a randomised, double-b lind fashion,The patients were randomly assigned to one of four groups. In group I, 3 ml ropivacaine 7,5 mg/ml were injected pre-operatively 5 minutes before the start of OR into each tonsil bed. In group II, 3 ml ropivacaine 7,5 mg/ml were injected post-operatively into each tonsil bed. In group II I, 3 ml NaCl were injected pre-operatively 5 minutes before the start of OR into each tonsil bed. In group IV, 3 ml NaCl were injected post-operativel y into each tonsil bed. The analgesic effectiveness was measured post-opera tively by the use of a visual analogue scale, a numeric rating scale (at re st and during activity) and by measuring the total analgesic comsumption (m efenamic acid) in the first 192 hours. In addition the time of first analge sic request was noted. Vital parameters and side-effects were documented. Results: There was no significant difference between the groups in the time of first analgesic request. Likewise, there was no significant difference in the post-operative cumulative analgesic consumption between the four gro ups. The post-operative administration of ropivacaine resulted in significa ntly lower pain scores at certain time points compared with the other group s as measured both with the visual analogue scale and the numeric rating sc ale (at rest). It must be emphasized, that the pain scores both at rest and with exertion remain high and that the net analgesic consumption (per day) remains constant for the first 8 post-operative days. Conclusions: We could demonstrate no significant pre-emptive analgesic effe ct with ropivacaine in adults undergoing tonsillectomy in our study. One ca n, however, recommend the administration of ropivacaine post-operatively af ter tonsillectomy, since a reduction of pain scores can thereby be achieved . For post-operative analgesia we recommend the combination of a non-opioid analgesic with a weak opioid.