Plasma ropivacaine concentrations after ultrasound-guided transversus abdominis plane block

The analgesic efficacy of subcostal transversus abdominis plane block with Mercedes incision

Background

Conventional perioperative analgesic modalities (e.g. opioids, epidural analgesia) have their own drawbacks, which limit their clinical application. This study investigated the opioid-sparing effectsof the oblique subcostal transversus abdominis plane (OSTAP) blockade with ropivacaine for the patients undergoing open liver resection with a Mercedes incision.

Methods

126 patients who were scheduled for open liver resection were enrolled in this study. Patients were randomly assigned to receive bilateral ultrasound-guided OSTAPblocks with either 0.375% ropivacaine (groupT) or 0.9% isotonic saline (group C). Both groups also received intravenous patient-controlled analgesia and intravenous 40 mg parecoxib every 12 h for a total of 3 days. Preoperative and intraoperative parameters, plus intraoperative and postoperative cumulative sufentanil consumption, were recorded.

Results

70 patients were enrolled in the study finally. There were no significant differences between the two groups with respect to preoperative parameters, and surgical and anesthetic characteristics. The intraoperative sufentanil use, cumulative sufentanil consumption at 5 min after extubation, 2 h, 4 h,12 h and 24 h after operation in group T was significantly less than that in group C (P = 0.001, 0.001, 0.000, 0.000, 0.001 and 0.044, respectively). Compared with group C, postoperative NRS pain scores at rest were significantly lower at 2 h and 4 h postoperatively in group T (P = 0.04and 0.02, respectively); NRS scores at the time of coughing were also significantly lower in group T than in group C at all time points except 5 min after extubation (all P < 0.001). Furthermore, compared with group C, the number of intraoperative vasodilator use, the extubation time and the incidence of nausea was reduced in group T.

Conclusion

Ultrasound-guided OSTAP block with ropivacaine can significantly decrease the perioperative cumulative dosage of analgesics and improve analgesic effect without obvious side effects for the patients who underwent an open liver resection with Mercedes incision when compared tothe ultrasound-guided OSTAP block with saline.

Trial registration

The study protocol was registered at http://www.chictr.org.cn (ChiCTR-TRC- 14004827) on February 19, 2014.

Preperitoneal postcesarean section bupivacaine analgesia: Comparison between dexamethasone and dexmedetomidine as adjuvants

Background:

The peritoneal wound is frequently neglected during laparotomy. The preperitoneal local anesthetics and many adjuvants were effective for postcesarean analgesia. Analgesia may involve somatic and autonomic components. The preperitoneal bupivacaine and the promising adjuvants dexamethasone or dexmedetomidine were compared in this study.

Patients and Methods:

Sixty patients subjected to a cesarean section (CS) under general anesthesia divided into two groups using a bolus of preperitoneal bupivacaine 0.7 mg/kg with either 1ug/kg dexmedetomidine (Group P) or 8 mg dexamethasone (Group D). The time to the first analgesic request was the primary outcome.

Results:

There was a significantly prolonged time to the first analgesic request in the Group P than the Group D and less required preperitoneal injections in the Group P, also pain assessed by Numerical Rating Scale (NRS) was lower in the Group P than the Group D after 6 h postoperatively up to 24 h.

Conclusions:

Dexmedetomidine provided better analgesia than dexamethasone as an adjuvant to preperitoneal bupivacaine post-CS.

Comparison of ultrasound-guided posterior transversus abdominis plane block and lateral transversus abdominis plane block for postoperative pain management in patients undergoing cesarean section: a randomized double-blind clinical trial study

Background

Due to the importance of pain control after abdominal surgery, several methods such as transversus abdominis plane (TAP) block are used to reduce the pain after surgery. TAP blocks can be performed using various ultrasound-guided approaches. Two important approaches to do this are ultrasound-guided lateral and posterior approaches. This study aimed to compare the two approaches of ultrasound-guided lateral and posterior TAP blocks to control pain after cesarean section.

Materials and methods

In this double-blind clinical trial study, 76 patients scheduled for elective cesarean section were selected and randomly divided into two groups of 38 and underwent spinal anesthesia. For pain management after the surgery, one group underwent lateral TAP block and the other group underwent posterior TAP block using 20cc of ropivacaine 0.2% on both sides. Pain intensity was evaluated based on Numerical Analog Scale (NAS) at rest and when coughing, 2, 4, 6, 12, 24 and 36 hours after surgery.

Results

The pain at rest in the posterior group at all hours post surgery was lower than the lateral group, especially at 6, 12 and 24 hours after the surgery and the difference was statistically significant (p=0.03, p<0.004, p=0.001).

Conclusion

The results of this study show that ultrasound-guided posterior TAP block compared with the lateral TAP block was more effective in pain control after cesarean section.

Randomised Comparison of Three Types of Continuous Anterior Abdominal Wall Block after Midline Laparotomy for Gynaecological Oncology Surgery

Effective analgesia after midline laparotomy surgery is essential for enhanced recovery programs. We compared three types of continuous abdominal wall block for analgesia after midline laparotomy for gynaecological oncology surgery. We conducted a single-centre, double-blind randomised controlled trial. Ninety-four patients were randomised into three groups to receive two days of programmed intermittent boluses of ropivacaine (18 ml 0.5% ropivacaine every four hours) via either a transversus abdominis plane (TAP) catheter, posterior rectus sheath (PRS) catheter, or a subcutaneous (SC) catheter. All groups received patient-controlled analgesia with morphine, and regular paracetamol and non-steroidal anti-inflammatory medication. Measured outcomes included analgesic and antiemetic usage and visual analog scores for pain, nausea, vomiting, and satisfaction. Eighty-eight patients were analysed (29 SC, 29 PRS and 30 TAP). No differences in the primary outcome were found (median milligrams morphine usage on day two SC 28, PRS 25, TAP 21, P=0.371). There were differences in secondary outcomes. Compared with the SC group, the TAP group required less morphine in recovery (0 mg versus 6 mg, P=0.01) and reported less severe pain on day one (visual analog scores 36.3 mm versus 55 mm, P=0.04). The TAP group used fewer doses of tropisetron on day one compared with the PRS group (8 versus 21, P=0.016). Programmed intermittent boluses of ropivacaine delivered via PRS, TAP and SC catheters can be provided safely to patients undergoing midline laparotomy surgery. Initially TAP catheters appear superior, reducing early opioid and antiemetic requirements and severe pain, but these advantages are lost by day two.

Effect of Adding Dexmedetomidine to Ropivacaine on Ultrasound-Guided Dual Transversus Abdominis Plane Block after Gastrectomy

OBJECTIVES

Transversus abdominis plane (TAP) block is an analgesic technique. Adding dexmedetomidine can enhance regional anesthesia. This study's aim was to evaluate whether dexmedetomidine prolonged analgesic time of TAP block after gastrectomy.

METHODS

Patients scheduled for gastrectomy were randomly assigned to receive a TAP block with saline (group S), ropivacaine (group R), or ropivacaine and dexmedetomidine (group RD). Visual analogue scale (VAS) scores, postoperative nausea and vomiting (PONV) scores, sedation scores, tramadol consumption, ropivacaine concentration, and Quality of Recovery Questionnaire 40 (QoR-40) were recorded.

RESULTS

Patients in group R and group RD had lower VAS scores 2, 4, 12, and 24 h after surgery compared with group S (P < 0.05). PONV scores were lower in group R and group RD compared with group S after 2, 12, 24, and 36 h (P < 0.05). Patients in group R and group RD required less tramadol and had better QoR-40 scores than those in group S (P < 0.05). The aforementioned variables and ropivacaine concentrations did not differ between group R and group RD (P > 0.05). Sedation scores were similar between three groups (P > 0.05).

CONCLUSIONS

TAP block can provide analgesia and improve the quality of recovery. Adding dexmedetomidine does not significantly improve the quality or duration of TAP block.

[Why and how to perform an ultrasound-guided transversus abdominis plane block: A step-by-step approach]

Used in clinical practice as part of a multimodal analgesic regimen, the transversus abdominis plane block (TAP block) is a relative novel procedure in which local anaesthetic agents are injected into the anatomic neurofascial space between the internal oblique and the transversus abdominis muscle. It allows a significantly prolonged duration of analgesia during the early postoperative stage in abdominal surgery. This regional anesthesia technique provides analgesia to the skin, muscles of the anterior abdominal wall and parietal peritoneum in order to decrease the incision-related pain. Thus, it reduces postoperative opiate requirements and opioids-related side effects (nausea, vomiting, delayed resumption of intestinal transit, drowsiness, respiratory depression, urine retention). Additionally, the TAP block appears particularly interesting when neuraxial techniques or opioids are contraindicated. Moreover, the ultrasound-guided procedure provides a significant success rate of this block and additionally avoids major complications. We describe our technique of ultrasound-guided TAP block and discuss its indications, contraindication and potential complications.

Levobupivacaine absorption pharmacokinetics with and without epinephrine during TAP block: analysis of doses based on the associated risk of local anaesthetic toxicity

PURPOSE

Cases of local anaesthetic systemic toxicity (LAST) periodically occur following transversus abdominal plane (TAP) blocks. The aim of this study was to characterize levobupivacaine absorption pharmacokinetics, with and without epinephrine, and estimate the risk of LAST, based on a previously reported toxic threshold.

METHODS

Previously reported data from 11 volunteers receiving ultrasound-guided TAP blocks with and without epinephrine on two independent occasions were analysed. Serial venous concentrations were measured for 90 min. A pharmacokinetic analysis was performed using the NONMEM statistical programme. The use of epinephrine in the solution was included in the analysis of covariates. The associated risk of LAST symptoms associated with different levobupivacaine dose schemes with and without epinephrine was estimated in 1000 simulated subjects.

RESULTS

A one-compartment first-order input and elimination model adequately fit the levobupivacaine data. Epinephrine prolonged the levobupivacaine absorption half-life {4.22 [95 % confidence interval (CI) 2.53-6.50] vs. 7.02 [95 % CI 3.74-14.1]; p < 0.05} and reduced its relative bioavailability (0.84; 95 % CI 0.72-0.97; p < 0.05) The derived model predicts that levobupivacaine dose schemes should be halved from 3 mg kg(-1) body weight with epinephrine to 1.5 mg kg(-1) without epinephrine to obtain a comparable risk of anaesthetic toxicity symptoms of approximately 0.1 %.

CONCLUSIONS

Our results strongly support the addition of epinephrine to the local anaesthetic solution, especially when doses of levobupivacaine of >1.5 mg kg(-1) are required. Recommendations regarding the maximum allowable doses of local anaesthetics should consider population analysis to determine safer dosage ranges.

Adding a transversus abdominis plane block to parenteral opioid for postoperative analgesia following trans-abdominal hysterectomy in a low resource setting: a prospective, randomised, double blind, controlled study

Background

The current gold standard treatment for acute postoperative pain after major abdominal surgery is multimodal analgesia using patient controlled analgesia delivery systems. Patient controlled analgesia systems are expensive and their routine use in very low income countries is not practical. The use of ultrasound in anaesthesia has made some regional anaesthesia blocks technically easy and safe to perform. This study aimed to determine whether adding an ultrasound guided transversus abdominis plane block as an adjunct to the current parenteral opioid based regimen would result in superior pain relief after a trans abdominal hysterectomy compared to using parenteral opioids alone.

Methods

Thirty-two elective patients having trans abdominal hysterectomy were recruited into a prospective randomised double-blind, controlled study comparing a bilateral transversus abdominis plane block using 21 ml of 0.25 % bupivacaine and 4.0 mg dexamethasone with a sham block containing 21 ml 0.9 % saline. Sixteen patients were allocated to each group. Anaesthesia and postoperative analgesia was left to the attending anaesthetist’s discretion. Primary outcome was visual analogue scale for pain at 2 h and 4 h. Secondary outcomes were time to first request for analgesia, visual analogue scale for comfort and bother. The data were analysed using the Statistical Package for Social Sciences (SPSS version 16).

Results

There was no statistically significant difference in the demographics of the two groups regarding weight, height, physical status and type of surgical incision. There was a statistically significant difference in visual analogue scale for pain at 4 h during movement with lower pain scales in the test group (p = 0.034). Women in the control group had an average pain free period of 56.8 min (median 56.5 min) before requesting a rescue analgesic compared to 116.5 min (median 103 min) in the study group. The between group difference in the average total analgesia duration was statistically significant at the 0.05 level (p = 0.005).

Conclusion

The addition of a bupivacaine–dexamethasone transverse abdominis plane block to intramuscular opioid does produce superior acute post-operative pain relief following a hysterectomy. However a single-shot block has a limited duration of action, and we recommend a repeat block.

Trial registration: Clinical trials registration was obtained PACTR201501000965252.http//www.pactr.org/ATMWeb/appmanager/atm/atmregistry?_nfpb=true&_windowLabel=BasicSearchUpdateController_1&BasicSearchUpdateController_1_actionOverride=%2Fpageflows%2Ftrial%2FbasicSearchUpdate%2FviewTrail&BasicSearchUpdateController_1id=965. The trial was registered on the 12th Dec 2014

Ropivacaine (total and unbound) and AGP concentrations after transversus abdominis plane block for analgesia after abdominal surgery

BACKGROUND

The goal of this study was to assess the safety of single bolus dose of ropivacaine (ROP) followed by continuous infusion through transversus abdominis plane block catheter. The aim was to determine ROP absorbed from the infusion site, changes in protein binding after surgery, and clinical determinants of adverse effects.

METHODS

Twelve patients undergoing laparotomy, received bilateral transversus abdominis plane block under ultrasound guidance using a 20-mL bolus of 0.5% ROP followed by 10 mL/h of 0.2% ROP infusion for 48 hours. Serial blood samples were drawn presurgery and to 48 hours postbolus. Plasma concentrations of total and unbound ROP were measured by high performance liquid chromatography with ultraviolet detection. Alpha-1 acid glycoprotein concentrations were measured by enzyme-linked immunosorbent assay. Patients were monitored for any signs or symptoms of central nervous system and chorionic villus sampling toxicity.

RESULTS

After the bolus dose, the mean (±SD) peak plasma total (bound plus unbound) ROP concentration (Cmax) was 2.1 (±0.8) mg/L and unbound ROP concentration was 0.04 (±0.02) mg/L. During the infusion phase, total ROP concentration continued to rise to a mean (±) Cmax of 3.3 (±1.6) mg/L, and the peak unbound concentration was 0.06 (±0.0) mg/L. No patients showed symptoms of ROP toxicity or unacceptable QTc intervals.

CONCLUSIONS

Although the total ROP concentrations approached or exceeded reported neurotoxicity thresholds, no patients had unbound ROP concentrations approaching the unbound toxicity threshold, nor showed any signs or symptoms of toxicity. This result was consistent with changes in protein binding to alpha-1 acid glycoprotein after surgery.

Transversus abdominis plane block vs. wound infiltration in Caesarean section: a randomised controlled trial

BACKGROUND

Multiple studies suggest that transversus abdominis plane (TAP) block (without intrathecal morphine) after Caesarean section (CS) reduces post-operative morphine consumption. In our study, we wanted to compare the analgesic effect of TAP block with infiltration of the wound after CS.

METHODS

We included 60 pregnant women scheduled for elective CS under spinal anaesthesia in a randomised, single-centre, double-blind study. Thirty patients received ultrasound-guided TAP block using 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml bilaterally and 20 ml normal saline as wound infiltration (TAP group). The other 30 patients (the control group) received normal saline 20 ml bilaterally in the TAP, and 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml as wound infiltration. The main outcome was cumulative morphine consumption at 48 h after surgery. In addition, continuous morphine consumption, pain scores and side effects were registered.

RESULTS

Fifty-seven patients completed the study. Cumulative morphine consumption at 48 h (mean±standard deviation) was 41±34 mg in the TAP group and 38±27 mg in the control group (P=0.7); a difference of 3 mg (95% confidence interval -13 to 19 mg). Morphine consumption at any time up to 48 h was virtually identical in both groups. Side effects were similar, except for a higher degree of sedation in the TAP group (P=0.04).

CONCLUSION

Compared with wound infiltration with local anaesthetics, TAP block did not reduce cumulative morphine consumption following CS. The TAP block was associated with more pronounced sedation.

The analgesic efficacy of ultrasound-guided transversus abdominis plane block with mid-axillary approach after gynecologic laparoscopic surgery: A randomized controlled trial

Background and Aims:

The transversus abdominis plane (TAP) block is widely used in clinical practice as a part of the multimodal analgesic regimen after abdominal surgery. The analgesic efficacy of ultrasound (US)-guided TAP block with the mid-axillary approach was investigated in patients undergoing laparoscopic gynecologic surgery in a randomized controlled clinical trial.

Materials and Methods:

Adult patients (n = 119) undergoing laparoscopic gynecologic surgery were randomized to undergo either TAP block with ropivacaine (Group A, n = 60) or that with saline (Group B, n = 59), in a blinded manner. Following general anesthesia, TAP block was performed bilaterally by infusion of either 20-mL 0.375% ropivacaine/one side in Group A or 20-mL saline/one side in Group B, under US guidance with a mid-axillary approach. Patient-controlled analgesia (PCA) was performed postoperatively with tramadol. The analgesic effect was postoperatively evaluated using a four-grade pain score and the prince Henry pain scale (PHS) at 0, 6, 12, and 24 h. Postoperative tramadol PCA consumption and vomiting/nausea were recorded. Statistical analyses were performed using the Mann-Whitney U-test or Fisher's exact probability test. A P < 0.05 was considered significant.

Results:

There was no statistically significant difference in background characteristics. The dose of remifentanil was significantly higher in Group B (P = 0.01). The pain score (P = 0.02) and PHS (P = 0.01) were significantly lower in Group A at 0 h. Tramadol PCA consumption in the period of 0-6 h (P = 0.01) and postoperative nausea (P = 0.04) were significantly less in Group A.

Conclusion:

Postoperative pain/nausea and PCA consumption were significantly lower in patients with TAP block in the early postoperative stage. TAP block with a mid-axillary approach holds considerable promise as a part of a balanced postoperative analgesic regimen following laparoscopic gynecologic surgery.

Ultrasound-guided tranversus abdominis plane block for herniorrhaphy in children: what is the optimal dose of levobupivacaine?

BACKGROUND

Regional anaesthesic techniques are commonly used for the management of pain following lower abdominal surgery in children. The transversus abdominis plane (TAP) block has shown promise for perioperative analgesia, but data on the optimal dose regimen are limited.

OBJECTIVE

To evaluate the optimal dose of levobupivacaine for successful ultrasound-guided TAP block in children.

DESIGN

A dose finding prospective study using Dixon's up-and-down sequential method.

SETTING

University Hospital Paediatric Anaesthesia Unit.

PATIENTS

Twenty-seven consecutive children aged 1 to 5 years scheduled for day-case elective herniorrhaphy.

INTERVENTION

After standardised induction of general anaesthesia, ultrasound-guided TAP block was performed with a fixed volume of 0.2  ml  kg(-1) of levobupivacaine solution. The dose of levobupivacaine was determined by Dixon's up-and-down method starting from 0.5  mg  kg(-1)with an interval of 0.1 mg   kg(-1). Block failure was defined as a 20% increase in heart rate or mean arterial pressure from baseline. Rescue analgesia consisted of intravenous remifentanil infusion during surgery and intravenous nalbuphine in the postanaesthetic care unit (PACU). Patients were assessed using the FLACC (face, legs, activity, cry and consolability) pain scale, the rescue analgesic consumption in the PACU and day-case unit and the postoperative pain measure for parents score at home.

MAIN OUTCOME MEASURES

The mean effective dose of levobupivacaine resulting in an effective TAP block in 50% of cases (ED50) obtained by using Dixon's up-and-down sequential method. The ED50 and ED95 were further estimated by bootstrapping.

RESULTS

The ED50 according to the up-and-down staircase method was 0.22  mg   kg(-1) [95% confidence interval (CI) 0.19 to 0.25]. Bootstrap replicates of the original dataset resulted in ED50 and ED95 estimates of 0.16  mg    kg(-1) (95% CI 0.11 to 0.24) and 0.43 mg  kg(-1)(95% CI 0.30 to 0.57), respectively.

CONCLUSION

As part of a multimodal analgesia strategy, ultrasound-guided TAP block with 0.2  ml  kg(-1)of 0.2% levobupivacaine provides successful peroperative analgesia in 95% of children who underwent herniorrhaphy.

Is transverse abdominis plane block effective following local anesthetic infiltration in laparoscopic totally extraperitoneal hernia repair?

Background

Transverse abdominis plane (TAP) block can be recommended as a multimodal method to reduce postoperative pain in laparoscopic abdominal surgery. However, it is unclear whether TAP block following local anesthetic infiltration is effective. We planned this study to evaluate the effectiveness of the latter technique in laparoscopic totally extraperitoneal hernia repair (TEP).

Methods

We randomly divided patients into two groups: the control group (n = 37) and TAP group (n = 37). Following the induction of general anesthesia, as a preemptive method, all of the patients were subjected to local anesthetic infiltration at the trocar sites, and the TAP group was subjected to ultrasound-guided bilateral TAP block with 30 ml of 0.375% ropivacaine in addition before TEP. Pain was assessed in the recovery room and post-surgery at 4, 8, and 24 h. Additionally, during the postoperative 24 h, the total injected dose of analgesics and incidence of nausea were recorded.

Results:

On arrival in the recovery room, the pain score of the TAP group (4.33 ± 1.83) was found to be significantly lower than that of the control group (5.73 ± 2.04). However, the pain score was not significantly different between the TAP group and control group at 4, 8, and 24 h post-surgery. The total amounts of analgesics used in the TAP group were significantly less than in the control group. No significant difference was found in the incidence of nausea between the two groups.

Conclusions

TAP block following local infiltration had a clinical advantage only in the recovery room.

Regional anesthesia for vascular surgery

Patients presenting for vascular surgery present a challenge to anesthesiologists because of their severe systemic comorbidities. Regional anesthesia has been used as a primary anesthetic technique for many vascular procedures to avoid the cardiovascular and pulmonary perturbations associated with general anesthesia. In this article the use of regional anesthesia for carotid endarterectomy, open and endovascular abdominal aortic aneurysm repair, infrainguinal arterial bypass, lower extremity amputation, and arteriovenous fistula formation is described. A focus is placed on reviewing the literature comparing anesthetic techniques, with brief descriptions of the techniques themselves.

Ultrasound-guided rectus sheath block or wound infiltration in children: a randomized blinded study of analgesia and bupivacaine absorption

BACKGROUND

Rectus sheath block can provide analgesia following umbilical hernia repair. However, conflicting reports on its analgesic effectiveness exist. No study has investigated plasma local anesthetic concentration following ultrasound-guided rectus sheath block (USGRSB) in children.

OBJECTIVES

Compare the effectiveness and bupivacaine absorption following USGRSB or wound infiltration (WI) for umbilical hernia repair in children.

METHODS

A randomized blinded study comparing WI with USGRSB in 40 children undergoing umbilical hernia repair was performed. Group WI (n = 20) received wound infiltration 1 mg·kg(-1) 0.25% bupivacaine. Group RS (n = 20) received USGRSB 0.5 mg·kg(-1) 0.25% bupivacaine per side in the posterior rectus sheath compartment. Pain scores and rescue analgesia were recorded. Blood samples were drawn at 0, 10, 20, 30, 45, and 60 min.

RESULTS

Patients in the WI group had a twofold increased risk of requiring morphine (hazard ratio 2.06, 95% CI 1.01, 4.20, P = 0.05). When required, median time to first morphine dose was longer in the USGRSB group (65.5 min vs. 47.5 min, P = 0.049). Peak plasma bupivacaine concentration was higher following USGRSB than WI (median: 631.9 ng·ml(-1) IQR: 553.9-784.1 vs. 389.7 ng·ml(-1) IQR: 250.5-502.7, P = 0.002). Tmax was longer in the USGRSB group (median 45 min IQR: 30-60 vs. 20 min IQR: 20-45, P = 0.006).

CONCLUSIONS

USGRSB provides more effective analgesia than WI for umbilical hernia repair. USGRSB with 1 mg·kg(-1) 0.25% bupivacaine is associated with safe plasma bupivacaine concentration that peaks higher and later than WI. Caution against using larger volumes of higher concentration local anesthetic for USGRSB is advised.

Comparing the effectiveness of ropivacaine 0.5% versus ropivacaine 0.2% for transabdominis plane block in providing postoperative analgesia after appendectomy

OBJECTIVE

The basis for the transversus abdominis plane (TAP) block involves infiltration of a local anesthetic into the neurofascial plane between the internal oblique and the transversus abdominis muscles, causing a regional block that spreads between the L1 and T10 dermatomes. Thus, the TAP block is said to be suitable for lower abdominal surgery. This study was designed to compare the analgesic efficacy of two different concentrations of ropivacaine for TAP block in patients undergoing appendectomy.

METHODS

Fifty-six patients with American Society of Anesthesiologists physical status I or II, aged 18 years and above, undergoing appendectomy were recruited in this prospective, randomized, double-blind study. They were divided into two groups: Group A patients who received 0.5 mL/kg of ropivacaine 0.5% and Group B patients who received 0.5 mL/kg of ropivacaine 0.2% via TAP block under ultrasound guidance. Postoperative pain was assessed using the visual analog scale upon arrival at the recovery room in the operating theatre, just prior to being discharged to the ward, and at 6 hours, 12 hours, 18 hours, and 24 hours postoperatively to compare the effectiveness of analgesia.

RESULTS

Intraoperatively, patients in Group B required a significantly greater amount of additional intravenous fentanyl than those in Group A. There were no significant statistical differences in pain scores at rest and on movement at all assessment times as well as in the dose of 24-hour intravenous morphine consumption given via patient-controlled analgesia postoperatively between the two groups.

CONCLUSION

The effectiveness of two different concentrations of ropivacaine (0.5% versus 0.2%) given via TAP block was comparable in providing postoperative analgesia for patients undergoing appendectomy.

Intravenous patient-controlled fentanyl with and without transversus abdominis plane block in cirrhotic patients post liver resection

Background

Coagulation changes can complicate liver resection, particularly in patients with cirrhosis. The aim of this prospective hospital-based comparative study was to compare the postoperative analgesic efficacy of intravenous fentanyl patient-controlled analgesia (IVPCA) with and without transversus abdominis plane (TAP) block.

Methods

Fifty patients with Child’s A cirrhosis undergoing liver resection were randomly divided into two groups for postoperative analgesia, ie, an IVPCA group receiving a 10 μg/mL fentanyl bolus of 15 μg with a 10-minute lockout and a maximum hourly dose of 90 μg, and an IVPCA + TAP group that additionally received TAP block (15 mL of 0.375% bupivacaine) on both sides via a posterior approach with ultrasound guidance before skin incision. Postoperatively, bolus injections of bupivacaine 0.375% were given every 8 hours through a TAP catheter inserted by the surgeon in the open space during closure of the inverted L-shaped right subcostal with midline extension (subcostal approach) guided by the visual analog scale score (<3, 5 mL; 3 to <6, 10 mL; 6–10, 15–20 mL) according to weight (maximum 2 mg/kg). The top-up dosage of local anesthetic could be omitted if the patient was not in pain. Coagulation was monitored using standard coagulation tests.

Results

Age, weight, and sex were comparable between the groups (P>0.05). The visual analog scale score was significantly lower at 12, 18, 24, 48, and 72 hours (P<0.01) in IVPCA + TAP group. The Ramsay sedation score was lower only after 72 hours in the IVPCA + TAP group when compared with the IVPCA group (1.57±0.74 versus 2.2±0.41, respectively, P<0.01). Heart rate, systolic blood pressure, and fentanyl consumption were lower in the IVPCA + TAP group at 24, 48, and 72 hours (P<0.05). Intensive care unit stays were significantly shorter with TAP (2.61±0.74 days versus 4.35±0.79 days, P<0.01). Prothrombin time and International Normalized Ratio indicated temporary hypocoagulability in both groups.

Conclusion

Combining TAP with IVPCA improved postoperative pain management and reduced fentanyl consumption, with a shorter stay in intensive care. TAP block can be included as part of a balanced multimodal postoperative pain regimen.

Transversus abdominis plane block does not improve early or late pain outcomes after Cesarean delivery: a randomized controlled trial

OBJECTIVES

Cesarean delivery is a common surgical procedure with anticipated substantial postoperative pain. The addition of a transversus abdominis plane block (TAPB) to a multimodal analgesic regimen that includes intrathecal morphine may provide improved early pain outcomes and decrease the risk of chronic post-surgical pain. The purpose of this research was to assess the ability of an ultrasound-guided TAPB with low-dose ropivacaine to decrease early postoperative pain, opioid consumption, and risk of developing persistent pain when compared with a placebo block.

METHODS

Eighty-three women were randomly assigned to either a treatment (0.25% ropivacaine) or control group (0.9% saline) in this double-blind trial, and 74 women were included in the final analysis. Ultrasound-guided TAPBs were performed with an injection of 20 mL of study solution per side. The primary outcome measures of this study were: pain at rest and pain after movement measured with a numeric rating scale, results of the Quality of Recovery-40 (QoR-40) questionnaire, and opioid consumption at 24 hr. These were used with an a priori sample size calculation to detect a 30% reduction in pain scores, a 10% improvement in QoR-40 score, and a 50% reduction in opioid consumption. Health quality and physical functioning were assessed using the Short Form 36 (SF-36®) Health Survey at 30 days and six months.

RESULTS

Assessment at 24 hr after Cesarean delivery revealed no clinically important differences between groups in postoperative pain, QoR-40, or opioid consumption. There were no clinically important differences between groups regarding measures of nausea, pruritus, vomiting, urine retention (2, 24, and 48 hr postoperatively), 24-hr QoR-40 sub-dimensions, or the SF-36 Health Survey (30 days and six months postoperatively).

CONCLUSIONS

Ultrasound-guided TAPB did not improve postoperative pain, quality of recovery, or opioid consumption 24 hr following surgery. Similar health and functioning (SF-36) at 30 days and six months were reported by both groups. This trial was registered at ClinicalTrials.gov number: NCT01261637.

Ultrasound-guided transversus abdominis plane (TAP) block for laparoscopic gastric-bypass surgery: a prospective randomized controlled double-blinded trial

BACKGROUND

Despite the laparoscopic approach, patients can suffer moderate to severe pain following bariatric surgery. This randomized controlled double-blinded trial investigated the analgesic efficacy of ultrasound-guided transversus abdominis plane (TAP) blocks for laparoscopic gastric-bypass surgery.

METHODS

Seventy patients undergoing laparoscopic gastric-bypass surgery were randomized to receive either bilateral ultrasound-guided subcostal TAP block injections after induction of general anesthesia or none. All patients received trocar insertion site local anesthetic infiltration and systemic analgesia. The primary outcome was cumulative opioid consumption (IV morphine equivalent) during the first 24 h postoperatively. Interval opioid consumption, pain severity scores, rates of nausea or vomiting, and rates of pruritus were measured during phase I recovery, and at 24 and 48 h postoperatively.

RESULTS

There was no difference in cumulative opioid consumption during the first 24 h postoperatively between the TAP (32.2 mg [95% CI, 27.6-36.7]) and control (35.6 mg [95% CI, 28.6-42.5]; P = 0.41) groups. Postoperative opioid consumptions during phase I recovery and the 24-48-h interval were similar between groups, as were pain scores at rest and with movement during all measured intervals. The rates of nausea or vomiting and pruritus were equivalent.

CONCLUSIONS

Bilateral TAP blocks do not provide additional analgesic benefit when added to trocar insertion site local anesthetic infiltration and systemic analgesia for laparoscopic gastric-bypass surgery.

Transversus abdominis plane block following abdominally based breast reconstruction: study protocol for a randomized controlled trial

BACKGROUND

Breast reconstruction using the free muscle-sparing transversus abdominus myocutaneous or deep inferior epigastric perforator flaps are common methods for restoring mastectomy defects for breast cancer patients. Despite its increasing popularity and safety, the abdominal donor site remains a major source of postoperative pain. Conventional postoperative pain relief protocol consists primarily of a patient-controlled anesthesia device delivering intravenous opioids. Opioids can cause numerous side effects such as sedation, headache, nausea, vomiting, breathing difficulties and bladder and bowel dysfunction. A promising approach to provide postoperative pain control of the abdominal incision is the newly developed transversus abdominis plane peripheral nerve block.

METHODS/DESIGN

This study is a double-blind, placebo-controlled, randomized controlled trial designed to rigorously test the effectiveness of a transversus abdominis plane catheter delivering intermittent local anesthetic in reducing postoperative abdominal pain following abdominal tissue breast reconstruction. The primary objective of this study is compare the mean total opioid consumption in the first postoperative 48 hours between the control and study groups including the patient-controlled anesthesia amounts and oral narcotic doses converted to intravenous morphine equivalent units. The secondary outcome measures include the following parameters: total in-hospital cumulative opioid consumption; daily patient-reported pain scores; total in-hospital cumulative anti-nausea consumption; nausea and sedation scores; and Quality of Recovery score; time to first bowel movement, ambulation, and duration of hospital stay.

DISCUSSION

Autologous breast reconstruction using abdominal tissue is rapidly becoming the reconstructive option of choice for postmastectomy patients across North America. A substantial component of the pain experienced by patients after this abdominally based procedure is derived from the abdominal wall incision. By potentially decreasing the need for systemic opioids and their associated side effects, this transversus abdominis plane block study will utilize the most scientifically rigorous double-blind, placebo-controlled, randomized controlled trial methodology to potentially improve both clinical care and health outcomes in breast cancer surgery patients.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01398982.

Bilateral transversus abdominis plane (TAP) block with 24 hours ropivacaine infusion via TAP catheters: A randomized trial in healthy volunteers

Background

The analgesic effect of a TAP block has been investigated in various surgical settings. There are however limited information about block level and block duration. Furthermore, there is a lack of information about continuous TAP block after ultrasound-guided posterior TAP blocks.

The aim of this double-blind randomized study was therefore to investigate the effect of an ultrasound-guided posterior TAP block with 24 hours local anesthetic infusion via a TAP catheter.

Methods

In this randomized study 8 male volunteers received a bilateral TAP block (20 mLs 0.5% ropivacaine) and were allocated to receive active infusion (ropivacaine 0.2% 5 mL/hr) via a TAP catheter on one side and placebo infusion on the other side. Primary outcome: Dermatomal sensory block involvement after 24 hours evaluated with pinprick. Secondary outcomes: Sensory block involvement evaluated with cold test and heat-pain detection thresholds (HPDT) on the abdominal wall. Assessment points: 15 min before block performance and 1, 4, 8, 12 and 24 hours after block performance.

Results

The TAP block primarily involved sensory changes in the Th10 to Th12 dermatomes. On the placebo side there was a decrease in extension beginning at 4–8 hours after block performance and with no detectable effect beyond 12 hours. Median number of dermatomes anesthetized (pinprick) at 24 hours after block performance was 1.5 (0–3) on the active side compared with 0 (0–0) on the placebo side (P = 0.039).

There were no statistical significant between-side differences in HPDT measurements at 24 hours after block performance.

Conclusions

The spread of sensory block following ultrasound-guided posterior TAP block is partly maintained by a continuous 24 hour ropivacaine infusion through a TAP catheter.

Trial registration

The study was registered at NCT01577940