Continuous transversus abdominis plane (TAP) blocks for postoperative pain control after hernia surgery: a randomized, triple-masked, placebo-controlled study.

BACKGROUND: Single-injection transversus abdominis plane (TAP) block provides postoperative analgesia and decreases supplemental analgesic requirements. However, there is currently no evidence from randomized, controlled studies investigating the possible benefits of continuous TAP blocks. Therefore, the aim of this randomized, triple-masked, placebo-controlled study was to determine if benefits are afforded by adding a multiple-day, ambulatory, continuous ropivacaine TAP block to a single-injection block following hernia surgery. METHODS: Preoperatively, subjects undergoing unilateral inguinal (N=19) or peri-umbilical (N=1) hernia surgery received unilateral or bilateral TAP perineural catheter(s), respectively. All received a ropivacaine 0.5% (20 mL) bolus via the catheter(s). Subjects were randomized to either postoperative perineural ropivacaine 0.2% or normal saline using portable infusion pump(s). Subjects were discharged home where the catheter(s) were removed the evening of postoperative day (POD) 2. Subjects were contacted on POD 0-3. The primary endpoint was average pain with movement (scale: 0-10) queried on POD 1. RESULTS: Twenty subjects of a target 30 were enrolled due to the primary surgeon's unanticipated departure from the institution. Average pain queried on POD 1 for subjects receiving ropivacaine (N=10) was a mean (standard deviation) of 3.0 (2.6) vs 2.8 (2.7) for subjects receiving saline (N=10; 95% confidence interval difference in means -2.9 to 3.4; P=0.86). There were no statistically significant differences detected between treatment groups in any secondary endpoint. CONCLUSIONS: The results of this study do not support adding an ambulatory, continuous ropivacaine infusion to a single-injection ropivacaine TAP block for hernia surgery. However, the present investigation was underpowered, and further study is warranted.

Preliminary experience with a novel ultrasound-guided supraclavicular perineural catheter insertion technique for perioperative analgesia of the upper extremity.

OBJECTIVE: Brachial plexus perineural catheters provide specific analgesia for upper extremity surgery. Although single-injection ultrasound-guided supraclavicular blocks have been described, little is known about the efficacy of perineural catheters inserted using this approach. We present our experience with ultrasound-guided supraclavicular perineural catheters for distal upper extremity surgery. METHODS: In this case series, 10 patients who underwent upper extremity surgery for orthopedic trauma at a tertiary care university hospital received a supraclavicular brachial plexus perineural catheter for postoperative pain management. In all patients, a nonstimulating catheter was inserted using an ultrasound-guided technique with the catheter tip remaining under direct vision until placement needle withdrawal. Postoperatively, a perineural ropivacaine, 0.2%, infusion was administered at a basal rate of 6 mL/h with a patient-controlled bolus of 4 mL and a lockout interval of 30 minutes. RESULTS: Of the 10 patients, all had successful perineural catheter placement. Patients required a median (range) of 0 (0-100) µg of fentanyl for catheter insertion analgesia. There were no vascular punctures or other direct procedure-related complications. Catheters were maintained for a median (range) of 4 (2-5) days in both hospitalized and ambulatory patients. Median (range) pain scores on postoperative days 1 and 2 were 5 (0-7) and 4 (3-6), respectively, on a numeric rating scale. Three patients' catheters were removed by patient request or dislodged on postoperative day 1. CONCLUSIONS: Supraclavicular brachial plexus perineural catheter insertion using ultrasound guidance is feasible and deserves further study with a randomized controlled trial comparing this relatively new technique with more established approaches.

Pharmacokinetic Profile and Tolerability of Liposomal Bupivacaine Following a Repeated Dose via Local Subcutaneous Infiltration in Healthy Volunteers.

BACKGROUND: Liposomal bupivacaine is indicated for administration into the surgical site to produce post-surgical analgesia. OBJECTIVES: The objectives of this study were to characterize the pharmacokinetic and safety profiles of liposomal bupivacaine following a repeated dose in healthy volunteers. METHODS: Healthy adults were assigned to receive liposomal bupivacaine via subcutaneous infiltration in a single 266 mg dose (cohort 1) or in two 266 mg doses, with the second dose given immediately, 24, 48, or 72 h after the first dose (cohorts 2-5). Pharmacokinetic parameters were estimated from blood samples collected up to day 14. Subjects were monitored for adverse events and assessed for neurologic function, cardiac function, and infiltration area abnormalities. RESULTS: Twelve subjects were assigned to each cohort. The mean ± standard deviation maximum observed plasma concentration (C max) of bupivacaine after a single dose was 129 ± 47 ng/mL. The mean C max after the second dose was higher, but always less than double the C max for cohort 1. The highest individual C max (589 ng/mL) was observed in a subject who received the second dose 24 h after the first dose (cohort 4), but was well below the reported thresholds for neurotoxicity and cardiac toxicity (2000 and 4000 ng/mL, respectively). A single and repeated dose were well-tolerated, and there were no clinically meaningful findings regarding neurologic examinations and electrocardiography. CONCLUSIONS: The mean C max following a repeated dose of liposomal bupivacaine remained well below accepted values for central nervous system and cardiac toxicity. Liposomal bupivacaine was well-tolerated and revealed no clinically important safety signals. CLINICALTRIALS. GOV IDENTIFIER: NCT02210247.

Retrospective analysis of quality improvement when using liposome bupivacaine for postoperative pain control.

BACKGROUND/OBJECTIVE: Liposome bupivacaine, a prolonged-release bupivacaine formulation, recently became available at the Naval Medical Center San Diego (NMCSD); before availability, postsurgical pain for large thoracic/abdominal procedures was primarily managed with opioids with/without continuous thoracic epidural (CTE) anesthesia. This retrospective chart review was part of a clinical quality initiative to determine whether postsurgical outcomes improved after liposome bupivacaine became available. METHODS: Data from patients who underwent laparotomy, sternotomy, or thoracotomy at NMCSD from May 2013 to May 2014 (after liposome bupivacaine treatment became available) were compared with data from patients who underwent these same procedures from December 2011 to May 2012 (before liposome bupivacaine treatment became available). Collected data included demographics, postoperative pain control methods, opioid consumption, perioperative pain scores, and lengths of intensive care unit and overall hospital stays. RESULTS: Data from 182 patients were collected: 88 pre-liposome bupivacaine (laparotomy, n=52; sternotomy, n=26; and thoracotomy, n=10) and 94 post-liposome bupivacaine (laparotomy, n=49; sternotomy, n=31; and thoracotomy, n=14) records. Mean hospital stay was 7.0 vs 5.8 days (P=0.009) in the pre- and post-liposome bupivacaine groups, respectively, and mean highest reported postoperative pain score was 7.1 vs 6.2 (P=0.007), respectively. No other significant between-group differences were observed for the overall population. In the laparotomy subgroup, there was a reduction in the proportion of patients who received CTE anesthesia post-liposome bupivacaine (22% [11/49] vs 35% [18/52] pre-liposome bupivacaine). CONCLUSION: Surgeons and anesthesiologists have changed the way they manage postoperative pain since the time point that liposome bupivacaine was introduced at NMCSD. Our findings suggest that utilization of liposome bupivacaine may be a useful alternative to epidural anesthesia.

Ultrasound-guided transversus abdominis plane catheters and ambulatory perineural infusions for outpatient inguinal hernia repair.

BACKGROUND AND OBJECTIVES: Transversus abdominis plane (TAP) blocks anesthetize the lower abdominal wall, and TAP catheters have been used to provide prolonged postoperative analgesia after laparotomy. The use of TAP catheters on an outpatient basis has not yet been described. We present our experience with ultrasound-guided TAP perineural catheter insertion and subsequent management of ambulatory TAP local anesthetic infusions after inguinal hernia repair. METHODS: Three patients scheduled for unilateral open inguinal hernia repair underwent preoperative posterior TAP catheter placement for postoperative pain management using a technique employing ultrasound guidance alone. A bolus of local anesthetic solution was injected via the catheter in divided doses, and block onset was confirmed before surgery. Postoperatively, a continuous infusion of ropivacaine 0.2% was delivered using a portable infusion pump, and patients were discharged with a prescription for oral analgesics for breakthrough pain and perineural infusion instructions. Patients were followed up daily by telephone. RESULTS: All patients underwent successful TAP catheter insertion and maintained their catheters until postoperative day 2. All patients reported minimal pain for the duration of infusion without the need for any supplemental opioid analgesics, high satisfaction with postoperative analgesia, and no infusion-related complications. CONCLUSIONS: An ultrasound-guided TAP catheter and ambulatory local anesthetic perineural infusion are a promising option for prolonged postoperative analgesia after outpatient inguinal hernia repair. A posterior insertion permits preoperative placement by keeping the catheter away from the planned surgical field.