Efficacy of preemptive analgesia for wound pain after laparoscopic operations in infertile women: a randomised, double-blind and placebo control study

The role of port site local anesthetic injection in laparoendoscopic single site surgery: a prospective randomized study

Objective

To investigate the role of port-site bupivacaine hydrochloride injection in laparoendoscopic single-site surgery (LESS) as a means of postoperative umbilical pain alleviation.

Methods

A total of 200 consecutive patients who underwent LESS from October 2018 to February 2019 were included in this randomized prospective case control study. The patients were alternatively assigned to either the study group (0.25% 10-mL bupivacaine hydrochloride injection at the 1.5-cm umbilical incision site after surgery) or the control group (no injection). All patients underwent surgery at the National Health Insurance Service Ilsan Hospital under the same operational setting by 3 board-certified gynecologists. Postoperative umbilical pain scores assessed using the visual analog scale were compared between the 2 groups as the primary outcome. Student's t-test, χ² test, and a linear mixed model were used for the statistical analysis. A P-value of <0.05 was considered to be statistically significant.

Results

The patients' age, body mass index, and menopausal status; type of surgery performed; and need for additional trocar insertion exhibited a significant difference between the bupivacaine injection and non-injection groups. After adjusting for various confounding variables, the postoperative umbilical pain scores measured at postoperative 2–3 hours, 6–10 hours, 1 day, and 3 days did not exhibit a significant difference between the 2 groups.

Conclusion

Port-site bupivacaine injection in LESS did not show any additive effect in alleviation of postoperative umbilical pain.

Managing Postoperative Pain After Minimally Invasive Gynecologic Surgery in the Era of the Opioid Epidemic

In this review, we examine the evidence behind nonopioid medication alternatives, peripheral nerve blocks, surgical techniques, and postoperative recovery protocols that can help minimize and effectively treat postoperative pain after minimally invasive gynecologic surgery (MIGS). Because of the depth and heterogeneity of the data, a narrative review was performed of reported interventions. A comprehensive review was performed of PubMed, Embase, and the Cochrane Database with a focus on randomized controlled trials. In the absence of literature specific to benign gynecology, similar specialty or procedural data were reviewed. A variety of nonopioid medications, surgical techniques, and postoperative recovery protocols have shown significant improvements in postoperative pain after gynecologic surgery. Nonopioid medication options that are beneficial include acetaminophen, nonsteroidal anti-inflammatories, and antiepileptics. Incision infiltration with local anesthesia also significantly reduces pain. Surgically, minimally invasive approaches, reducing the laparoscopic trocar size to <10 mm, and evacuating the pneumoperitoneum at the end of the case all have significant benefits. Lastly, enhanced recovery pathways show promise in reducing pain after MIGS. By using a multimodal approach, minimally invasive gynecologic surgeons can help to minimize and manage postoperative pain with less reliance on opioid pain medications.

Port site infiltration of local anesthetic after laparoendoscopic single site surgery for benign adnexal disease

Objective

To determine whether local bupivacaine injection into the incision site after gynecologic laparoendoscopic single site surgery (LESS) improves postoperative pain.

Methods

This prospective cohort study included consecutive 158 patients who had LESS for benign adnexal disease from March 2013 to December 2015. Chronologically, 82 patients (March 2013 to August 2014) received no bupivacaine (group 1) and 76 (August 2014 to December 2015) received a bupivacaine block (group 2). For group 2, 10 mL 0.25% bupivacaine was injected into the 20 mm-incision site through all preperitoneal layers after LESS completion. Primary outcome is postoperative pain score using the visual analog scale (VAS).

Results

There was no difference in clinicopathological characteristics between the groups. Operating time (expressed as median [range], 92 [55–222] vs. 100 [50–185] minutes, P=0.137) and estimated blood loss (50 [30–1,500] vs. 125 [30–1,000] mL, P=0.482) were similar between the groups. Post-surgical VAS pain scores after 3 hours (3.5 [2–6] vs. 3.5 [2–5], P=0.478), 6 to 8 hours (3.5 [2–6] vs. 3 [1–8], P=0.478), and 16 to 24 hours (3 [2–4] vs. 3 [1–7], P=0.664) did not differ between groups.

Conclusion

Bupivacaine injection into the trocar site did not improve postoperative pain after LESS. Randomized trials are needed to evaluate the benefits of local bupivacaine anesthetic for postoperative pain reduction.

Duration of action of a topical anaesthetic formulation for pain management of mulesing in sheep

OBJECTIVE

To investigate the effect of topical anaesthesia on 'mothering up' of lambs after mulesing and marking, and for pain alleviation over a 24-h period.

DESIGN

Two separate trials were performed on Merino lambs undergoing the mules procedure for flystrike prevention, to assess the efficacy of immediate postoperative topical anaesthetic wound dressing containing lignocaine (hydrochloride) 40.6 g/L, bupivacaine (hydrochloride) 4.5 g/L, adrenaline (tartrate) 24.8 mg/L and cetrimide 5.0 g/L in a gel base (Bayer Animal Health, Gordon, NSW, Australia).

METHODS

In both trials, lambs were assigned to one of three treatment regimens: control, mules procedure with topical anaesthetic (0.5 mL/kg) and mules procedure without topical anaesthetic treatment. Parameters measured included body weight, assessment of skin and wound sensitivity to light touch and pain stimulation, behavioural responses and time to mother up and to feed.

RESULTS

In both trials there was rapid (1 min) and prolonged (up to 24 h) wound analgesia as shown by lower scores for light touch (P<0.001) and pain responses (P<0.001), with absent or significantly diminished primary and secondary hyperalgesia (P≤0.05) and significant reduction in pain-related behaviours (P<0.001) in treated versus untreated lambs.

CONCLUSION

Significant pain alleviation and improved recovery can be achieved in lambs for at least 24 h after mulesing through the use of topical anaesthesia. It is suggested that the haemostatic action of adrenalin, together with inhibition of the inflammatory cascade and the barrier effect of the gel within the product, may explain the prolonged anaesthesia up to 24 h observed in the present study. These results suggest that topical anaesthesia has the capacity to dramatically improve the welfare of lambs undergoing mulesing.

Topical anaesthesia alleviates short-term pain of castration and tail docking in lambs

OBJECTIVE

To investigate the effect of a topical anaesthetic formulation on pain alleviation, wound healing and systemic levels of local anaesthetic actives in lambs undergoing castration and tail docking.

DESIGN

Three placebo-controlled and/or randomised experiments were conducted using three groups of Merino lambs (n = 62, 68 and 19) undergoing routine castration and tail docking.

PROCEDURE

Surgical castration, with either surgical or hot-iron tail docking, was performed with and without the application of topical anaesthetic (Tri-Solfen) or placebo. The effects of this procedure were compared with those of rubber ring castration and tail docking, and of the handled but unmarked controls. Wound pain was assessed using calibrated Von-Frey monofilaments over a 4-h period, pain-related behaviour was assessed over 5 h, wound healing was assessed at 14 and 28 days, and the plasma levels of lignocaine and bupivacaine were determined.

RESULTS

Rapid and up to 4 h primary hyperalgesia developed following surgical castration and tail docking in the untreated and placebo-treated lambs. It was absent in the castration wounds, and significantly reduced in the tail-docking wounds, of the treated lambs. Hot-iron docking was associated with mild and transient secondary hyperalgesia, which was abolished by the topical anaesthesia. There was a significant reduction in pain-related behaviours in treated lambs, which were not significantly different in their behaviour to the sham-operation handled controls. Plasma lignocaine and bupivacaine levels were below the toxic thresholds in all tested lambs.

CONCLUSION

Topical anaesthesia alleviates wound pain and significantly reduces pain-related behaviours in lambs undergoing surgical castration plus surgical or hot-iron tail docking, without a negative effect on wound healing or a risk of systemic toxicity.

Better late than never? Impact of local analgesia timing on postoperative pain in laparoscopic surgery: a systematic review and metaanalysis

BACKGROUND

This study aimed to determine the effect of local anesthesia administered before laparoscopic surgery (preemptive anesthesia) on postoperative pain.

METHODS

The authors searched Medline, EMBase, and the Cochrane Central Register of Controlled Trials, as well as reference lists of textbooks and relevant articles. They contacted experts in the field of anesthesia and laparoscopic surgery for randomized controlled trials comparing preemptive administration of local anesthesia at the incision site or intraperitoneally with postoperative anesthesia administration or placebo. Trials were systematically assessed for eligibility and validity, and data were extracted in duplicate. The data were pooled across studies using a random effects model.

RESULTS

The 26 studies that met the inclusion criteria were included in the analysis. Preemptive incisional local anesthetic was superior to placebo in terms of visual analog pain scores (VAS) at 4 h (weighted mean difference [WMD], -9.49 mm; 95% confidence interval [CI], -15.50 to -3.48) and 24 h (WMD, -4.75 mm; 95%CI, -8.90 to 0.60). However, no difference was found between these measures and those for postoperative incision-site infiltration. Preemptive intraperitoneal local anesthetic was superior to placebo in terms of VAS at 4 h (WMD, 5.76 mm; 95%CI, -11.27 to -0.25), 8 h (WMD, -9.64 mm; 95%CI, -13.68 to -5.60), 12 h (WMD, -4.68 mm; 95%CI, -5.86 to -3.49), and 24 h (WMD, -5.57 mm; 95%CI, -8.35 to -2.79), and superior to postoperative anesthesia administration at 8 h (WMD, -7.42; 95%CI, -13.40 to -1.45), 12 h (WMD, -7.27 mm; 95%CI, -10.26 to -4.28), and 24 h (WMD, -7.95 mm; 95%CI, -12.33 to -3.56).

CONCLUSION

Preemptive administration of local anesthetic at the incision site reduces postoperative pain compared with placebo but achieves an analgesic effect similar to that of postincisional anesthetic infiltration. Preemptive local anesthetic administered intraperitoneally decreases postoperative pain compared with both placebo and postoperative infiltration. Surgeons should use local analgesia in laparoscopic surgery to decrease postoperative pain, but the timing of administration is significant only for intraperitoneal infiltration.

Prospective randomized trial of iliohypogastric-ilioinguinal nerve block on post-operative morphine use after inpatient surgery of the female reproductive tract

Objective

To determine the impact of pre-operative and intra-operative ilioinguinal and iliohypogastric nerve block on post-operative analgesic utilization and length of stay (LOS).

Methods

We conducted a prospective randomized double-blind placebo controlled trial to assess effectiveness of ilioinguinal-iliohypogastric nerve block (IINB) on post-operative morphine consumption in female study patients (n = 60). Patients undergoing laparotomy via Pfannenstiel incision received injection of either 0.5% bupivacaine + 5 mcg/ml epinephrine for IINB (Group I, n = 28) or saline of equivalent volume given to the same site (Group II, n = 32). All injections were placed before the skin incision and after closure of rectus fascia via direct infiltration. Measured outcomes were post-operative morphine consumption (and associated side-effects), visual analogue pain scores, and hospital length of stay (LOS).

Results

No difference in morphine use was observed between the two groups (47.3 mg in Group I vs. 45.9 mg in Group II; p = 0.85). There was a trend toward lower pain scores after surgery in Group I, but this was not statistically significant. The mean time to initiate oral narcotics was also similar, 23.3 h in Group I and 22.8 h in Group II (p = 0.7). LOS was somewhat shorter in Group I compared to Group II, but this difference was not statistically significant (p = 0.8). Side-effects occurred with similar frequency in both study groups.

Conclusion

In this population of patients undergoing inpatient surgery of the female reproductive tract, utilization of post-operative narcotics was not significantly influenced by IINB. Pain scores and LOS were also apparently unaffected by IINB, indicating a need for additional properly controlled prospective studies to identify alternative methods to optimize post-surgical pain management and reduce LOS.

Impact of topical anaesthesia on pain alleviation and wound healing in lambs after mulesing

OBJECTIVE

To investigate the impact of using the topical anaesthetic preparation Tri-Solfen on pain alleviation and wound healing in lambs undergoing mulesing.

DESIGN

Three separate trials, placebo controlled and/or randomised, were carried out over a 5 month period on three mobs of between 60 and 263 merino lambs undergoing routine mulesing.

PROCEDURE

Wound pain was assessed using 10 and 75 g calibrated Von-Frey monofilaments to determine sensitivity to light touch and pain stimulation over a 4 to 8 h period. Pain-related behaviour was documented by trained, blinded observers using a numerical rating scale. Wound healing rates were determined using scaled digital photography and image analysis software to calculate contraction in wound surface area 2 and 4 weeks after mulesing.

RESULTS

There was rapid (3 min) and prolonged (up to 8 h) wound analgesia as shown by pain response scores (P < or = 0.01), with absent or significantly diminished primary and secondary hyperalgesia (P < or = 0.01) and significant reduction in pain-related behaviour (P < 0.001) in treated versus untreated lambs. In addition there was improved wound healing in the treated lambs (P < or = 0.05).

CONCLUSION

Tri-Solfen effects rapid and prolonged wound analgesia, reduction in pain-related behaviour and improved wound healing in lambs undergoing routine mulesing, providing effective alleviation of pain associated with routine mulesing in sheep.

The Effect of Preemptive Pudendal Nerve Blockade on Pain After Transvaginal Pelvic Reconstructive Surgery

OBJECTIVE

To assess the effect of preemptive pudendal nerve blockade on pain and consumption of narcotic analgesia following transvaginal pelvic reconstructive surgery.

METHODS

This was a randomized, double-blind, placebo-controlled trial. Patients undergoing transvaginal pelvic reconstructive surgery under general anesthesia were randomized to receive pudendal block with either bupivacaine 0.25% or placebo (normal saline 0.9%) immediately before surgery. All patients received postoperative intravenous hydromorphone patient-controlled analgesia. Patients were asked to report on their pain intensity 1, 3, 5, 7, 18, and 24 hours postoperatively, using a validated visual analog pain scale from 0-10. Main outcome measures included postoperative pain intensity and hydromorphone consumption.

RESULTS

One hundred ten patients enrolled in the study, of whom 106 underwent randomization, and 102 received pudendal nerve blockade, 51 with bupivacaine and 51 with saline. Demographic and baseline clinical characteristics were not significantly different between the 2 patients groups. There were no significant differences in postoperative pain intensity (median scores: 1 hour, 4.0 versus 5.0; 3 hours, 3.0 versus 4.0; 7 hours, 2.0 versus 3.0; 18 hours, 3.0 versus 4.0), the consumption of hydromorphone (0-3 hours, 1.84 mg versus 1.77 mg; 4-7 hours, 1.19 mg versus 1.20 mg; 8-18 hours, 2.89 mg versus 2.35 mg), or mean hospital stay (39.6 versus 37.3 hours) between the bupivacaine and saline groups.

CONCLUSION

Preemptive pudendal nerve blockade does not affect postoperative pain intensity or the consumption of narcotic analgesia after transvaginal pelvic reconstructive surgery.

Preemptive port site local anesthesia in gynecologic laparoscopy: a randomized, controlled trial

STUDY OBJECTIVE

To assess the impact of preemptive infiltration of port site with local anesthetic on postlaparoscopy pain.

DESIGN

Randomized, double-blind, controlled trial (Canadian Task Force classification I).

SETTING

Two university hospitals.

PATIENTS

A total of 170 women scheduled for gynecologic laparoscopic procedures were randomly assigned to pre-incisional infiltration with ropivacaine (n = 86) or with saline solution (n = 84).

INTERVENTIONS

Infiltration with either local anesthetic or placebo was accomplished in each port site before skin incision. All patients underwent standard anesthesia induction and maintenance.

MEASUREMENTS AND MAIN RESULTS

Postoperative pain was evaluated with a visual analogue scale and patient interview at 1, 3, and 24 hours after surgery. No difference was found between groups in pain levels, pain location, or in the site of superficial pain at any of the postoperative time periods. The proportion of women requiring analgesia before discharge was similar in the local anesthetic group and in the saline group (22/86 [25.6%] vs 19/84 [22.6%], p = .72). The analgesic consumption in the first 24 hours after surgery and the time to first analgesic request did not differ significantly between the two groups.

CONCLUSION

Preemptive infiltration of trocar sites with ropivacaine is not effective in postoperative pain relief.

Effect of bupivacaine after operative laparoscopic gynecologic procedures

STUDY OBJECTIVE

To evaluate the effect of intraperitoneal installation and periportal infiltration of bupivacaine on postoperative pain and return of bowel function.

DESIGN

A prospective, double-blind, randomized trial (Canadian Task Force classification I).

SETTING

GATA School of Medicine, Department of Obstetrics and Gynecology, Reproductive Endocrinology Unit.

PATIENTS

Eighty patients undergoing operative gynecologic laparoscopy.

INTERVENTION

Periportal infiltration of local anesthesia with 10 mL 0.5% bupivacaine before incision and another 20 mL 0.5% bupivacaine diluted with 20 mL of saline or equal amount of physiologic saline injected into the peritoneal cavity at the end of the procedure.

MEASUREMENTS AND MAIN RESULTS

Each patient recorded the severity of her pain on a visual analog scale (VAS) at 1, 6, 18, and 24 hours and the time of first bowel movement and first flatus after surgery. Seventy-seven patients completed the study (38 in the bupivacaine group; 39 in the control group). The severity of postoperative pain, as recorded on the VAS, was significantly less at 1, 6, 18, and 24 hours after surgery in the group receiving bupivacaine compared with those in the control group. The first bowel movement in the bupivacaine group occurred earlier than in the control group (284.80 +/- 31.62 min vs 453.23 +/- 33.08 min, p <.001); similarly, the first flatus occurred earlier in the bupivacaine group than in the control group (466.2 +/- 29.59 min vs 658.80 +/- 40.92 min p <.001).

CONCLUSION

Intraperitoneal installation and periportal infiltration of bupivacaine decrease postoperative pain and hasten the return of bowel function. Both decreased postoperative pain and shortened duration for the return of bowel function are crucial for comfort and discharge of the patient.

Local analgesia in laparoscopy: a randomized trial

OBJECTIVE

To investigate whether local infiltration of bupivacaine reduces postoperative pain at trocar sites during gynecologic laparoscopy.

METHODS

This was a randomized, placebo-controlled, double-blind clinical trial, using patients as their own controls. For each patient, 2 opposite trocar sites were infiltrated. One site was randomly chosen to receive 0.5% bupivacaine, and the other received 0.9% saline. In addition, patients were randomized into 2 cohorts to receive either preincision or postsurgical infiltration. Surgeons, patients, and interviewers were blinded toward the exposure. Postoperative pain was evaluated at 1 hour, 4 hours, and 24 hours after surgery using a 100-mm visual analog scale. Patients rated their pain at each of the infiltrated trocar sites. A 20-mm difference between pain scores was considered clinically significant. A paired t test was used for analysis.

RESULTS

Infiltration of bupivacaine at completion of surgery resulted in significantly decreased pain at 1 hour postoperatively (mean pain score 25.8 versus 48.6, P = .02). Mean pain scores at 4 hours and 24 hours were decreased, but not statistically different. Patients receiving bupivacaine before surgery did not have a statistically significant decrease in pain scores.

CONCLUSION

Infiltration of bupivacaine at completion of gynecologic laparoscopic surgery decreases pain at trocar sites in the immediate postoperative period.

Pre-emptive analgesia

Transmission of pain signals evoked by tissue damage leads to sensitization of the peripheral and central pain pathways. Pre-emptive analgesia is a treatment that is initiated before the surgical procedure in order to reduce this sensitization. Owing to this 'protective' effect on the nociceptive system, pre-emptive analgesia has the potential to be more effective than a similar analgesic treatment initiated after surgery. Theoretically, immediate postoperative pain may be reduced and the development of chronic pain may be prevented. Although some clinical studies have demonstrated significant effects on acute postoperative pain, no major clinical benefits of pre-emptive analgesia have been documented. The only way to prevent sensitization of the nociceptive system might be to block completely any pain signal originating from the surgical wound from the time of incision until final wound healing. Other pharmacological interventions, including 'antihyperalgesic' drugs such as NMDA-receptor antagonists and gabapentin, may interfere with the induction and maintenance of sensitization. Future studies will investigate the analgesic effect of prolonged multimodal combinations of different classes of 'traditional' analgesics and 'antihyperalgesics' on postoperative pain.