Two strategies of morphine administration on the control of post-surgical pain after anesthesia with remifentanil

Abstract

AIM: The post-operative pain (POP) is accompanied by autonomic, psychological and behavioural responses which can result in a significant increase in morbidity and mortality. The purpose of this study was to compare the efficacy and safety of intravenous bolus administration of morphine versus subcutaneous administration.

MATERIAL OF STUDY: Fifty subjects scheduled for elective abdominal surgery were randomized into a group S (n = 26) and group E (n = 24). The first group was administered morphine (0.35 mg/kg) subcutaneously immediately after induction of anesthesia, while the second group the same drug at a dose of 0.25 mg/kg was administered intravenously 45’ before the end of the intervention. All patients received intraoperative remifentanil (0,25-0,50 µg/kg/min), and at the end of surgery paracetameolo 1g and ondansetron 4mg. Upon awakening, the DPO has been reviewed by the NRS (numerical scale of pain) at time zero (T0), after 30’ (t1), 1h (T2) and 24h (T3). Furthermore, it was annotated request for rescue doses of morphine and the collateral effects.

RESULTS: The two study groups did not show significant differences related to the anthropometric characteristics, duration of surgery, type of surgery, ASA class. No difference between the two groups was highlighted during the evaluation of POP, through NRS scale and quantity of “rescue” doses requested. In group E there was a single case of respiratory depression.

CONCLUSIONS: Our study suggests that whether intravenous or subcutaneous administration of morphine, both simple and economical analgesic techniques, they are able to guarantee the same quality control of POP in patients undergoing abdominal surgery.