Continuous Right Thoracic Paravertebral Block For Postoperative Pain Treatment In Right Lobe Hepatectomy

ObjectiveTo observe the effect of continuous right thoracic paravertebral block for postoperativepain treatment in right lobe hepatectomy, and to guide the treatment of acute pain after liverresection.MethodsForty-eight patients undergoing right lobe hepatectomy were randomized to receiveeither continuous right thoracic paravertebral block (group P, n=24) or not (group C, n=24).Simple randomization was done by independent research staff using48opaque sealedenvelopes,24for each group, indicating group assignment and describing the anestheticprotocol.Before anesthesia, the group P had continuous right thoracic paravertebral block of T7performed under ultrasound guidance in the lateral position via a percutaneous intercostalsapproach. In the group C, the skin was penetrated1cm with a Tuohy needle at the same siteas in the group P and a catheter was fixed out of the skin. Thirty minutes before the end ofsurgery, group P had a10ml bolus of plain lidocaine1%via the paravertebral catheter,followed by an infusion of ropivacaine0.2%at6ml/h for24hrs. In the control group, nolocal anesthetics were injected and pumped. The syringes were covered with the samedressing to mask patient allocation. Patients were sent to the postanesthesia care unit(PACU) after postoperative awake and extubated. Once arrival at the PACU, all patientswere placed on a postoperative analgesic regimen that included patient-controlledintravenous analgesia (PCIA) with sufentanil for48hrs. Time to arrival at the PACU became time0for pain assessments. Pain at rest and oncoughing was recorded for each patient using NRS (0-10) at1,4,8,16, and24hrs sincePACU arrival. Analgesics use, postoperative nausea and vomiting events and satisfactionwith pain management during the first24hrs were also recorded. The length of hospital stayafter surgery of patients in the both groups were recorded.Results1. A total of48patients were prospectively enrolled in the study. Two patients in group Pwere excluded because of catheter obstruction and change of operation plan,respectively. Two patients were excluded from the control group because of change ofoperation plan and unplanned postoperative mechanical ventilation, respectively. Thus,data were analyzed on22patients in each group. The baseline characteristics ofpatients, such as ratio of gender, age, weight, height, ASA class, preoperative NRS, andduration of surgery were similar in both groups (P>0.05).2. The pain intensity at rest and on coughing using the NRS score was less in theparavertebral group compared with the control group for each time point (P<0.05). Thecumulative sufentanil consumption and frequency of PCIA at each time point in thecontrol group was significantly more compared with the paravertebral group (P <0.05).The cumulative sufentanil consumption of PCIA in group P (54.27±12.06μg) at24postoperative hours was more than20%below that in group C (68.05±9.86μg).3. The difference of MAP before and after paravertebral block was not obvious and theopioid consumption, blood loss, urine output, intra-operative fluids and transfusionrequirements between two groups were also similar (P>0.05).4. The indexes of liver function between the two groups were not significantly differentbefore and24hrs after surgery (P>0.05).5. No significant differences of adverse effect such as PONV, bloating, d izziness andrespiratory depression in the both groups were found (P>0.05). 6. The patient satisfaction was8.09in the paravertebral group and6.73in the controlgroup which had statistically significant difference (P<0.05).7. During the first24hrs, tramadol was administered to two patients in the control groupand no patient needed in paravertebral group. This difference between two groups wasnot obvious (P>0.05).8. The length of hospital stay after surgery of patients in group P (13.91±4.75) was longerthan that in group C (12.68±4.08), but the difference was not statistically significant (P=0.36).9. Twenty-two patients were all successfully blocked under the ultrasound guidance.There were no complications from the block procedure, such as bleeding, infection,intravascular injection, intrapleural injection, or local anesthetic toxicity.ConclusionContinuous thoracic paravertebral block has opioid sparing effect on sufentanil basePCIA for right lobe hepatectomy patients, reduced the incidence of PONV and respiratorydepression and could be incorporated into multimodal analgesic regimes as part ofenhanced recovery programmes for right lobe hepatectomy patients.