Impacts of different administration modes of dexmedetomidine with 0.5% ropivacaine on intercostal nerve block

To investigate the effectiveness and rationality of different administration modes of dexmedetomidine with 0.5% ropivacaine on intercostal nerve block.

In total, 150 patients aged from 20-45 years with a body mass index (BMI): 18.5-23.9 kg/m2, met the criteria from the American Society of Anesthesiologists (ASA) class: I-II, and underwent lumpectomy in our center were equally randomized into three groups using a table of random numbers. Group D1: perineural administration of dexmedetomidine 0.5 µg/kg + intercostal nerve block with 0.5% ropivacaine; group D2: intravenous infusion of dexmedetomidine0.5 µg/kg + intercostal nerve block with 0.5% ropivacaine; and group R: intercostal nerve block with 0.5% ropivacaine. The Numerical Rating Scale (NRS) of pain and the Ramsay Sedation Scale were used for assessing pain and sedation levels 4, 8, 12, and 24 hours after the operation. The total duration of analgesia, total requirement of rescue analgesia, and adverse reactions were recorded.

The NRS scores in groups D1 and D2 were significantly lower than that in group R, 8 hours after the operation (both P<0.05), and the NRS score in group D1 was significantly lower than in group D2 12 hours after the operation (P<0.05). The Ramsay scores showed no significant differences among all three groups at all time points after surgery. The duration of analgesia in group D1 was significantly longer than in group D2 (P<0.05). No rescue analgesia was needed in all three groups, and no adverse reactions such as dizziness, dry mouth, nausea, vomiting, and respiratory depression were reported.

The combinations of dexmedetomidine with ropivacaine for intercostal nerve blocking can prolong the duration of analgesia after lumpectomy; however, the duration of analgesia is longer via the perineural route than via the intravenous route.