Programmed intermittent bolus infusion versus continuous infusion of 0.2% levobupivacaine after ultrasound-guided thoracic paravertebral block for video-assisted thoracoscopic surgery A randomised controlled trial

BACKGROUND The analgesic benefits of programmed intermittent bolus infusion for thoracic paravertebral block remain unknown. OBJECTIVE The aim of this study was to compare the analgesia from intermittent bolus infusion with that of a continuous infusion after thoracic paravertebral block. DESIGN A randomised controlled study. SETTING A single centre between December 2016 and November 2017. Seventy patients scheduled for video-assisted thoracoscopic surgery were included in the study. INTERVENTION(S) Patients were randomly assigned to receive 0.2% levobupivacaine via continuous infusion (5 ml h(-1), continuous group) or programmed intermittent bolus infusion (15 ml every 3 h, bolus group) after an initial 15-ml bolus injection of 0.2% levobupivacaine. MAIN OUTCOME MEASURES The main outcome was the amount of rescue fentanyl (per kg of body weight) consumed within 24 h after surgery. Secondary outcomes were postoperative pain scores, plasma levobupivacaine concentrations and the number of dermatomes anaesthetised. RESULTS There was no significant difference between the continuous and bolus groups in the postoperative consumption of fentanyl (median [interquartile range] 5.5 [4 to 9.5] mg kg(-1) versus 6 [3.5 to 9] mg kg(-1) respectively, P = 0.45) and postoperative pain scores within 24 h. At 20 h after initiating the infusions, there was no statistically significant difference between the two groups in terms of the plasma levobupivacaine concentration. The number of dermatomes anaesthetised to pinprick and cold testing was significantly greater in the bolus group. CONCLUSION Our findings suggest that postoperative pain and opioid usage are similar with either programmed intermittent bolus infusion or continuous infusion after thoracic paravertebral block. Programmed intermittent bolus infusion provides a wider sensory blockade and could benefit patients requiring a wider extent of anaesthesia.