Application of continuous thoracic paravertebral nerve block guided by nerve stimulator on postoperative pain relief for nephrectomy

Abstract

To evaluate the effects of continuous paravertebral nerve block after nephrectomy. 60 cases receiving simple nephrectomy,American Society of Anesthesiologists(ASA) grading status I or II, aged from 30 to 65 years, weighing from 45 to 80 kg, male or female, were randomly divided into 2 groups: control group (CEA group ) and continuous paravertebral nerve block group (PVB group ), 30 patients in each one. Both groups were performed with 0.2% ropivacaine 250 ml in continuous infusion, assisted with intravenous morphine patient-controlled analgesia. The blood gas was examined in 6, 12, 24 and 48 h postoperatively, and the VAS scores of quiet state and motion state were assessed.In 48 h postoperation, the total amount of morphine was calculated and the complications cases were recorded. Compared with the CEA group, PaO2 in PVB group increased and PaCO2 declined significantly. There was no difference of VAS score under quiet state, but under the motion state the VAS scores declined significantly, the total amount of morphine reduced[ (5.2 ± 1.2) vs (13.9 ± 1.6) mg) ], the cases of nausea, vomiting, pruritus , orthostatic hypotension decreased and the postoperative first anal exhaust time interval shortened (P < 0.05). Compared with CEA, postoperative administration of PVB for open nephrectomy results in lowering morphine dose as well as side effect related with the use of morphine.