Programmed Intermittent Bolus Versus Continuous Infusion For Thoracic Paravertebral Block After Video-assisted Thoracoscopic Surgery:a Randomized Controlled Double-blind Study

BACKGROUND: The effectiveness of programmed intermittent bolus infusion(PIBI)in postoperative analgesia for thoracic paravertebral block(TPVB)remains unclear.The aim of this study was to compare postoperative analgesia and recoveries between PIBI and continuous infusion(CI)after video-assisted thoracic surgery(VATS).METHODS: Fifty-eight patients undergoing VATS received thoracic paravertebral(T5-6)punctures and catheters inserted after general anaesthesia induction from August 2019 to January 2021.All patients were randomly assigned to receive either a PIBI or CI combined with a patient-controlled analgesia(PCA)pump.The recorded data included the number of anaesthetized dermatomes,visual analogue scale(VAS)score for pain,frequency of PCA,patients’ analgesic satisfaction,use of rescue analgesics,complications for 3 days,and postoperative recovery.RESULTS: Compared with the CI group,the PIBI group had a greater number of dermatomes anaesthetized to pinpricks at 24 h postoperatively(P<0.001)and a lower frequency of PCA within 24 h to 48 h after surgery(P=0.040).The VAS scores 24 h after VATS in the PIBI group were lower than those in the CI group at rest(P=0.026)and during coughing(P=0.010).There was no statistically significant difference between the two groups in terms of the total frequency of PCA,the patients’ analgesic satisfaction or the need for tramadol rescue.The complications and postoperative recovery were similar in the two groups.CONCLUSIONS: PIBI achieved superior pain relief,less use of analgesics and a more number of anaesthetized dermatomes than continuous TPVB in patients undergoing video-assisted thoracoscopic unilateral lung resection surgery.A paravertebral bolus can expand the reach of a sensory blockade.