The Effect of Nefopam on Postoperative Fentanyl Consumption: A Randomized, Double-blind Study

Perioperative analgesic efficacy and adverse events of fentanyl in dentistry: A systematic review

OBJECTIVES

To assess the efficacy and adverse events linked to the utilization of fentanyl for perioperative pain management in dentistry.

METHODS

This systematic review of randomized clinical trials (RCTs) adhered to the PRISMA guidelines and incorporated various databases.

RESULTS

Eleven RCTs studying 674 patients were analyzed. Perioperative pain was predominantly evaluated in patients undergoing surgery for impacted molars, although some studies also included patients with other conditions such as oral submucous fibrosis, maxillary cancer, bony temporomandibular joint ankylosis, irreversible pulpitis, among others. Combined with dexmedetomidine, fentanyl produced enhanced analgesic effects. It demonstrated comparable efficacy when compared to nefopam and nalbuphine. Both intranasal and intravenous administration routes proved equally effective. In four RCTs, the transdermal fentanyl patch outperformed the control group, except in the clinical trial where it was compared to ropivacaine. The main adverse events associated with the use of fentanyl included nausea, vomiting, drowsiness, delirium, and respiratory depression; however, they were like those reported in the comparison groups.

CONCLUSIONS

While fentanyl demonstrated satisfactory perioperative analgesic efficacy, there were other alternatives that displayed better or comparable outcomes. Due to the risks and potential for misuse of fentanyl, these alternatives must be considered although adverse events were also reported.

Optimizing patient-controlled analgesia: a narrative review based on a single center audit process

Intravenous patient-controlled analgesia (PCA) is valuable for delivering opioids in a flexible and timely manner. Although it is designed to offer personalized analgesia driven by the patients themselves, users often report insufficient pain relief, which can be addressed by optimizing its settings and multimodal analgesia. We adopted a systematic approach to modify PCA protocols by utilizing a serial audit process based on institutional PCA data. This review retrospectively examined the process, encompassing data from 13,230 patients who had used PCA devices. The two modifications to the fentanyl-based PCA protocols resulted in three distinct phases. In the first phase, high opioid consumption and unintended PCA withdrawal were the common issues. These were addressed in the second phase by omitting the routine use of basal infusion. However, this led to increased delivery-to-demand ratios, mitigated in the third phase by increasing the bolus dose from 15 μg to 20 μg. These serial protocol changes have produced varied outcomes across different surgical departments, underscoring the need for careful and gradual adjustments and thorough impact assessments. Drawing insights from this audit process, we incorporated findings from the literature on PCA settings and multimodal analgesic approaches. This review underscores the significance of iterative feedback and refinement of analgesic protocols to achieve optimal postoperative pain management. Additionally, it discusses critical considerations regarding the postoperative audit processes.

Nefopam as a multimodal analgesia in thoracoscopic surgery: a randomized controlled trial

Background

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive procedure. However, some patients still experience severe pain after VATS. Pain after VATS can disturb deep breathing and coughing, and can increase postoperative pulmonary complications. Therefore, multidisciplinary pain management is emphasized for enhanced recovery after VATS. Nefopam is a centrally-acting, non-opioid, non-steroidal analgesic drug, and its pain reduction effect in many surgeries has been reported. We sought to determine whether administration of nefopam is effective as multimodal analgesia in VATS.

Methods

This study enrolled patients aged 19 years or older, and scheduled for elective VATS lobectomy with American Society of Anesthesiologists (ASA) physical class I-III. Forty-six participants were randomly divided into a group receiving nefopam (group N), and a control group (group O) in a 1:1 ratio. The study participants, and the researcher collecting the data were blinded to the group allocation. For the group N, nefopam 20 mg was administered before surgical incision and also at the end of surgery while chest tube was inserted. For the group O, normal saline 100 mL was administered. The primary outcome of this study was the pain score, by verbal numerical rating scale, at rest and upon coughing.

Results

Forty-five participants (group N =22, group O =23) were involved in the statistical analysis. Nefopam reduced pain at rest at 0 h [8 (IQR, 5-10) vs. 4 (IQR, 2-7), P=0.01], and at 0-1 h [5 (IQR, 5-8) vs. 3 (IQR, 2-5), P=0.001]. Pain upon coughing decreased with nefopam at 0 h [9 (IQR, 6-10) vs. 6 (IQR, 2-8), P=0.009], 0-1 h [6 (IQR, 5-8) vs. 5 (IQR, 2-6), P=0.001], and at 12-24 h [4 (IQR, 3-7) vs. 3 (IQR, 1-4), P=0.03]. Injection of 20 mg of nefopam before incision and at the end of surgery relieved postoperative pain at 0 h, 1 h at rest and at 0 h, 1 h, 12-24 h with coughing after VATS.

Conclusions

Therefore, nefopam can serve as a useful component of multimodal analgesia for pain management after VATS.

Trial Registration

ClinicalTrials.gov (NCT05173337).

Evaluation of basal rate infusion in intravenous patient-controlled analgesia for post-cesarean section pain management: A randomized pilot study

OBJECTIVE

Administering opioids via intravenous patient-controlled analgesia is a prevalent approach for managing postoperative pain. Nevertheless, due to concerns about opioid-related side effects and the potential for opioid tolerance, there is a growing emphasis on adopting opioid-sparing techniques for postoperative pain management. We aimed to investigate the effect of adding a basal rate infusion in fentanyl-based IVA following a cesarean section (CS).

METHOD

Forty-eight patients, who received pain management through IVA after CS, were assigned randomly into 3 groups based on the background rate setting: Group 0 (0 mcg/hour, n = 16), Group 1 (15 mcg/hour, n = 16), and Group 2 (30 mcg/hour, n = 16). We assessed the impact of the basal infusion rate on opioid consumption and the visual analog scale (VAS) scores during the first 48 hours post-CS and also investigated opioid-induced side effects and the requirement for rescue analgesics in the ward during the first 48 hours after CS.

RESULTS

In the initial 24 hours following CS, fentanyl consumption significantly increased in Group 2 compared with Group 0 and Group 1 (P = .037). At 24 hours, VAS scores both at rest and during movement, tended to decrease, as the basal rate increased; however, no significant differences were observed between the groups (P = .218 and 0.827, respectively). Between the first 24- and 48-hours post-CS, fentanyl consumption showed a marked increase in both Group 1 and Group 2 compared to Group 0 (P < .001). At 48 hours, the VAS scores at rest displayed a trend toward reduction; however, no significant differences between groups were evident (P = .165). Although the incidence of opioid-induced complications was noted, no statistically significant differences were recorded between groups during the initial 24 hours and subsequent 24 to 48 hours period (P = .556 and P = .345, respectively).

CONCLUSION

The inclusion of a basal fentanyl infusion in the IVA protocol did not provide any advantages over an IVA devoid of a basal rate infusion in managing acute pain following CS.

Risk factors for discontinuation of intravenous patient-controlled analgesia after general surgery: a retrospective cohort study

Identifying patients at risk for developing side effects secondary to intravenous patient-controlled analgesia (IV PCA) and making the necessary adjustments in pain management are crucial. We investigated the risk factors of discontinuing IV PCA due to side effects following general surgery; adult patients who received IV PCA after general surgery (2020-2022) were included. Data on postoperative pain intensity, PCA pain relief, side effects, continuity of PCA use, and PCA pump settings were collected from the records of the acute pain management team. The primary outcome was identifying the risk factors associated with PCA discontinuation due to side effects. Of the 8745 patients included, 94.95% used opioid-containing PCA, and 5.05% used non-steroidal anti-inflammatory drug (NSAID)-only PCA; 600 patients discontinued PCA due to side effects. Female sex (adjusted odds ratio [aOR] 3.31, 95% confidence interval [CI] 2.74-4.01), hepato-pancreatic-biliary surgery (aOR 1.43, 95% CI 1.06-1.94) and background infusion of PCA (aOR 1.42, 95% CI 1.04, 1.94) were associated with an increased likelihood of PCA discontinuation. Preoperative opioid use (aOR 0.49, 95% CI 0.28-0.85) was linked with a decreased likelihood of PCA discontinuation. These findings highlight the importance of individualized pain management, considering patient characteristics and surgical procedures.

Intravenous patient-controlled analgesia regimen in postoperative pain management following elective cesarean section: A single-center retrospective evaluation

Intravenous patient-controlled analgesia (IV PCA; IVA) is the most widely used method for postoperative pain management. An appropriate IVA regimen is required, depending on the expected intensity of pain after surgery. This study expected that a decrease in the second prescription rate of IVA after elective cesarean section (CS) would help establish an appropriate regimen for the initial IVA. We retrospectively reviewed the records of 632 patients who were prescribed IVA after CS. We classified patients into phase 1 (basal rate 15.00 mcg/hours, bolus dose 15.00 mcg, total volume 100 mL) and phase 2 (basal rate 31.25 mcg/hours, bolus dose 31.25 mcg, nefopam 60 mg, paracetamol 3 g, total volume 160 mL) according to the IVA regimen, and patients in phase 2 were classified into the basal 15 group and basal 30 group according to the basal rate of IVA. We compared the rates of second prescription, drug removal, and side effects of IVA between the 2 phases and the 1 group. We analyzed the data of 631 eligible patients. The second prescription rate of IVA in phase 2 was 3.77%, a significant decrease compared to that in phase 1 (27.48%); however, the incidence of complications in phase 2 was 6.92%, a significant increase compared to that in phase 1 (0.96%). Within phase 2, in the basal 30 group, the basal rate was almost double that in the basal 15 group. However, there were no significant differences in the rate of second prescription, removed drug IVA, or adverse events between the basal 15, and 30 groups. In the case of CS, which has a high degree of postoperative pain, it is beneficial to control acute pain by properly setting the regimen of the initial IVA with a basal rate infusion to nullify a second prescription.

Postoperative analgesia of intraoperative nefopam in patients undergoing anterior cervical spine surgery: A prospective randomized controlled trial

BACKGROUND

Nefopam is a non-opioid, non-nonsteroidal anti-imflammatory drug, analgesic drug that inhibits the reuptake of serotonin, norepinephrine, and dopamine. It is widely used as an adjuvant for pain. This study investigated whether the intraoperative, intravenous infusion of nefopam (20 mg) reduces postoperative morphine consumption, pain scores, and alleviates neuropathic pain in patients undergoing cervical spine surgery.

METHODS

A prospective, paralleled design, randomized study was conducted on 50 patients (aged 18-75 years) in a university-based hospital. The patients were assigned to an intervention or a control group (25 patients in each). The intervention group received a 1-hour infusion of nefopam (20 mg) before the end of surgery. The control group received normal saline (NSS). The outcome measures were morphine consumption during the first 24 postoperative hours, numerical rating scale (NRS) pain scores, and scores for the Thai version of the Neuropathic Pain Symptom Inventory (NPSI-T) in patients with neuropathic pain and adverse drug reactions. The NPSI-T scores were assessed on the preoperative day, postoperative day 1, 3, 15, and 30. The outcome assessors were blinded to group allocation.

RESULTS

Fifty patients were analyzed. During the first 24 postoperative hours, morphine consumption was 8 mg (nefopam) and 12 mg (NSS; P = .130). The intervention and control groups demonstrated no significant differences in the median NRS scores or total NPSI-T scores or adverse drug reactions.

CONCLUSIONS

A single, intraoperative infusion of 20 mg of nefopam did not significantly reduce postoperative (24 hours) morphine consumption in patients undergoing anterior cervical spine surgery.

The usefulness of dual channel elastomeric pump for intravenous patient-controlled analgesia in geriatrics: a randomized, double-blind, prospective study

BACKGROUND

Intravenous patient-controlled analgesia (IV-PCA) is often used in the postoperative period. However, determining an appropriate opioid dose is difficult. A previous study suggested the usefulness of variable-rate feedback infusion. In this study, we used a dual-channel elastomeric infusion pump to provide changes in PCA infusion rate by pain feedback.

METHODS

Ninety patients undergoing orthopedic surgery of American Society of Anesthesiologists grade I-III and 65 to 79 years of age participated in the study. All patients were given a dual-chamber PCA. Patients were randomly allocated to a treatment group (Group D; PCA drugs divided into both chambers) or control group (Group C; PCA drugs only in the constant flow chamber with normal saline in the adjustable flow chamber). The primary outcome was the amount of fentanyl consumption via PCA bolus. The secondary outcome variables were pain score, total fentanyl consumption, rescue analgesic use, patient satisfaction, recovery scores, and adverse events including postoperative nausea and vomiting (PONV).

RESULTS

Group D showed decreased fentanyl consumption of the PCA bolus, a decrease in rescue analgesic use, and better patient satisfaction compared with group C. The incidence of PONV was much higher in group C. There was no difference in other adverse events.

CONCLUSIONS

We showed the usefulness of dual chamber IV-PCA to change the flow rate related to pain feedback without any complications. Our results suggest a noble system that might improve existing IV-PCA equipment.

TRIAL REGISTRATION

The study registered at UMIN clinical trial registry (registered date: 05/03/2020, registration number: UMIN000039702 ).

Comparison between the trapezius and adductor pollicis muscles as an acceleromyography monitoring site for moderate neuromuscular blockade during lumbar surgery

Acceleromyography at the adductor pollicis located in a distal part of the body may not reflect the degree of neuromuscular blockade (NMB) at the proximally located muscles manipulated during lumbar surgery. We investigated the usefulness and characteristics of acceleromyographic monitoring at the trapezius for providing moderate NMB during lumbar surgery. Fifty patients were randomized to maintain a train-of-four count 1–3 using acceleromyography at the adductor pollicis (group A; n = 25) or the trapezius (group T; n = 25). Total rocuronium dose administered intraoperatively [mean ± SD, 106.4 ± 31.3 vs. 74.1 ± 17.6 mg; P < 0.001] and surgical satisfaction (median [IQR], 7 [5–8] vs. 5 [4–5]; P < 0.001) were significantly higher in group T than group A. Lumbar retractor pressure (88.9 ± 12.0 vs. 98.0 ± 7.8 mmHg; P = 0.003) and lumbar muscle tone in group T were significantly lower than group A. Time to maximum block with an intubating dose was significantly shorter in group T than group A (44 [37–54] vs. 60 [55–65] sec; P < 0.001). Other outcomes were comparable. Acceleromyography at the trapezius muscle during lumbar surgery required a higher rocuronium dose for moderate NMB than the adductor pollicis muscle, thereby the consequent deeper NMB provided better surgical conditions. Trapezius as proximal muscle may better reflect surgical conditions of spine muscle.

Effect of Nefopam-Based Patient-Controlled Analgesia with and without Fentanyl on Postoperative Pain Intensity in Patients Following Laparoscopic Cholecystectomy: A Prospective, Randomized, Controlled, Double-Blind Non-Inferiority Trial

Background and Objectives: We investigated the non-inferiority of patient-controlled analgesia (PCA), using either nefopam alone or combined nefopam-fentanyl for postoperative analgesia in patients undergoing laparoscopic cholecystectomy. Materials and Methods: In this prospective, randomized, controlled study, 78 patients were allocated to receive nefopam 240 mg (Group N240) or nefopam 120 mg with fentanyl 600 μg (Group NF), equivalent to fentanyl 1200 μg, with a total PCA volume of 120 mL. Patients were given a loading dose (0.1 mL/kg) from the PCA device along with ramosetron (0.3 mg) and connected to a PCA device with a background infusion rate of 2 mL/h, bolus dose amount set at 2 mL, and lockout interval set at 15 min. Pain scores were obtained using the numeric rating scale (NRS) at 30 min after recovery room (RR) admission, as well as 8 and 24 h postoperatively. The primary outcome was analgesic efficacy evaluated using NRS-rated 8 h postoperatively. Other evaluated outcomes included the incidence rate of bolus demand, rescue analgesic and antiemetic requirements, and postoperative adverse effects. Results: NRS scores were not significantly different between the groups throughout the postoperative period (p = 0.539). NRS scores of group N240 were not inferior to those of group NF at 30 min after RR admission, or at 8 and 24 h postoperatively (mean difference [95% CI], -0.05 [-0.73 to 0.63], 0.10 [-0.29 to 0.50], and 0.28 [-0.06 to 0.62], respectively). Postoperative adverse effects were not significantly different between the two groups (p = 1.000) and other outcomes were also not significantly different between the two groups (p ≥ 0.225). Conclusions: PCA using nefopam alone has a non-inferior and effective analgesic efficacy and produces a lower incidence of postoperative adverse effects compared to a combination of fentanyl and nefopam after laparoscopic cholecystectomy.

Perioperative Intravenous Patient-Controlled Analgesic Efficacy of Morphine with Combined Nefopam and Parecoxib versus Parecoxib in Gynecologic Surgery: A Randomized, Double-Blind Study

Background

Nefopam is a non-NSAIDs and opioid sparing centrally acting drug which is effective for a multimodal postoperative analgesia. The present study aimed to evaluate the analgesic efficacy of nefopam combined with parecoxib for gynecologic surgery.

Methods

This randomized double-blinded control trial recruited participants (n = 72) who underwent gynecologic surgeries and divided them into either a nefopam or control group. The study group received parecoxib 40 mg plus nefopam 20 mg, while the control group received parecoxib 40 mg plus normal saline solution intravenously during open abdominal gynecological surgery. Both groups then received either nefopam or normal saline every 6 hours postoperatively for 24 hours. Intravenous patient-controlled analgesia with morphine was given for breakthrough pain within 24 h. The participants were evaluated for morphine consumption within 24 hours and postoperative pain using a verbal numerical rating scale (VNRS) at a postanesthetic care unit, at 6-, 12-, and 24-hour postoperative periods. Adverse effects were recorded.

Results

Morphine consumption within 24 hours and adverse effects were not significantly different between both groups. Mean difference and 95% confident interval of morphine consumption between both groups was 1.00 (−4.56, 4.76), P=0.97. The VNRS on movement at 6 hours after surgery of the nefopam group was significantly different from that of the control group [mean (SD), 4.14 (2.11) vs. 5.14 (1.80), P=0.04]. The VNRS of the nefopam group at 12 hours after operation during resting and on movement was significantly different from that of the control group ([mean (SD), 1.47 (1.80) vs. 2.54 (2.15), P=0.03], [mean (SD), 3.22 (1.84) vs 4.17 (1.74), P=0.03]), respectively.

Conclusions

The combined administration of nefopam and parecoxib during gynecologic surgery slightly reduced the VNRS at 6 and 12 hours postoperatively more than treatment with parecoxib.

Analgesic Efficacy of Nefopam as an Adjuvant in Patient-Controlled Analgesia for Acute Postoperative Pain After Laparoscopic Colorectal Cancer Surgery

Despite rapid advancements in laparoscopic surgical techniques and perioperative management, postoperative pain remains a significant clinical issue. We examined the analgesic efficacy of nefopam as an adjuvant in patient-controlled analgesia (PCA) for acute postoperative pain in patients undergoing laparoscopic colorectal cancer surgery. We retrospectively analyzed the medical records of 120 patients who did or did not receive 80 mg of nefopam as an adjuvant in fentanyl PCA; they were allocated to the nefopam (n = 60) or non-nefopam group (n = 60). The demographic, clinical, and anesthetic data, with data on pain severity and opioid administration at the postoperative anesthesia care unit (PACU) on postoperative days (PODs) 1, 3, and 5, were compared between the groups. The pain score and opioid administration did not differ at the PACU or on PODs 1, 3, or 5. The day of PCA discontinuation, time to pass flatus, length of the hospital stay, and incidence of nausea/vomiting, dizziness, and headache also did not differ between the groups. Fentanyl PCA with 80 mg of nefopam as an adjuvant did not have a superior analgesic effect after laparoscopic colorectal cancer surgery.

The Antiallodynic Effect of Nefopam on Vincristine-Induced Neuropathy in Mice

Background

Chemotherapy-induced neuropathic pain is a disabling condition following cancer treatment. Vincristine has more neurotoxicity than other vinca alkaloid agents. This study evaluated the correlation of different doses of nefopam with antiallodynic effects in a mouse vincristine neuropathy model.

Methods

A peripheral neuropathic mouse model was made by intraperitoneal injection of vincristine (0.1 mg/kg/day; 5-day-on, 2-day-off schedule over 12 days). After the development of allodynia, mice were injected intraperitoneally with 0.9% normal saline (NS group) or various doses (10, 30, 60 mg/kg) of nefopam (Nefopam group). We examined allodynia using von Frey hairs pre-administration and at 30, 60, 90, 120, 180, 240 mins, and 24 hrs after drug administration. We also measured the neurokinin-1 receptor concentrations in the spinal cord to confirm the antiallodynic effect of nefopam after drug administration.

Results

The peripheral neuropathic mouse model showed prominent mechanical allodynia. Intraperitoneal nefopam produced a clear dose-dependent increase in paw withdrawal threshold compared with pre-administration values and versus the NS group. The concentration of neurokinin-1 receptor was significantly decreased in the Nefopam group (P<0.05).

Conclusion

Intraperitoneally administered nefopam yielded a dose-dependent attenuation of mechanical allodynia and decreased neurokinin-1 receptor concentration, suggesting that the neurokinin-1 receptor is involved in the antiallodynic effects of nefopam in vincristine neuropathy.

Effects on postoperative nausea and vomiting of nefopam versus fentanyl following bimaxillary orthognathic surgery: a prospective double-blind randomized controlled trial

Background

Postoperative nausea and vomiting (PONV) frequently occurs following bimaxillary orthognathic surgeries. Compared to opioids, Nefopam is associated with lower incidences of PONV, and does not induce gastrointestinal tract injury, coagulopathy, nephrotoxicity, or fracture healing dysfunction, which are common side effects of Nonsteroidal anti-inflammatory drugs. We compared nefopam- and fentanyl-induced incidence of PONV in patients with access to patient-controlled analgesia (PCA) following bimaxillary orthognathic surgeries.

Methods

Patients undergoing bimaxillary orthognathic surgeries were randomly divided into nefopam and fentanyl groups. Nefopam 120 mg or fentanyl 700 µg was mixed with normal saline to a final volume of 120 mL. Patients were given access to nefopam or fentanyl via PCA. Postoperative pain intensity and PONV were measured at 30 minutes and 1 hour after surgery in the recovery room and at 8, 24, 48, and 72 hours after surgery in the ward. The frequency of bolus delivery was compared at each time point.

Results

Eighty-nine patients were enrolled in this study, with 48 in the nefopam (N) group and 41 in the fentanyl (F) group. PONV occurred in 13 patients (27.7%) in the N group and 7 patients (17.1%) in the F group at 8 hours post-surgery (P = 0.568), and there were no significant differences between the two groups at any of the time points. VAS scores were 4.4 ± 2.0 and 3.7 ± 1.9 in the N and F groups, respectively, at 8 hours after surgery (P = 0.122), and cumulative bolus delivery was 10.7 ± 13.7 and 8.6 ± 8.5, respectively (P = 0.408). There were no significant differences in pain or bolus delivery at any of the remaining time points.

Conclusion

Patients who underwent bimaxillary orthognathic surgery and were given nefopam via PCA did not experience a lower rate of PONV compared to those that received fentanyl via PCA. Furthermore, nefopam and fentanyl did not provide significantly different postoperative pain control.

Pain management after laparoscopic hysterectomy: systematic review of literature and PROSPECT recommendations

Background and objectives

Laparoscopic hysterectomy is increasingly performed because it is associated with less postoperative pain and earlier recovery as compared with open abdominal hysterectomy. The aim of this systematic review was to evaluate the available literature regarding the management of pain after laparoscopic hysterectomy.

Strategy and selection criteria

Randomized controlled trials evaluating postoperative pain after laparoscopic hysterectomy published between January 1996 and May 2018 were retrieved, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, from the EMBASE and MEDLINE databases and the Cochrane Register of Controlled Trials. Efficacy and adverse effects of analgesic techniques were assessed.

Results

Of the 281 studies initially identified, 56 were included. Of these, 31 assessed analgesic or anesthetic interventions and 25 assessed surgical interventions. Acetaminophen, non-steroidal anti-inflammatory drugs, and dexamethasone reduced opioid consumption. Limited evidence hindered recommendations on alpha-2-agonists. Inconsistent evidence was found in the studies investigating pregabalin and transversus abdominis plane block, and no evidence was found for intraperitoneal local anesthetics, port site infiltration, or single-port laparoscopy. Measures to lower peritoneal insufflation pressure or humidify or heat insufflated gas seem to reduce the incidence of shoulder pain, but not abdominal pain.

Conclusions

The baseline analgesic regimen for laparoscopic hysterectomy should include acetaminophen, a non-steroidal anti-inflammatory drug, dexamethasone, and opioids as rescue analgesics.

Association of nefopam use with postoperative nausea and vomiting in gynecological patients receiving prophylactic ramosetron: A retrospective study

Background

Postoperative nausea and vomiting (PONV) is a common adverse effect of opioid-based intravenous patient-controlled analgesia (IV PCA). Nefopam has been considered as a good candidate for inclusion in multimodal analgesia because of its opioid sparing effect, but it can be emetic. This study aims to examine whether the use of nefopam combined with fentanyl in IV PCA was associated with the higher incidence of PONV in patients receiving prophylactic ramosetron after gynecological surgery.

Methods

Data from 296 patients who underwent gynecological surgery were retrospectively reviewed. The patients received IV PCA containing either fentanyl 1500 μg and ketorolac 90 mg (Group K) or fentanyl 1500 μg and nefopam 80 mg (Group N). All patients in both groups received 0.3 mg of ramosetron at the end of surgery. The primary outcome measure was the incidence of PONV during the 3-day postoperative period.

Results

No difference was observed in the incidence of PONV during the 3-day postoperative period between the two groups. However, the incidence of nausea on postoperative day 2 was significantly higher in Group N (10.3%) than in Group K (2.8%) (P = 0.016). Multivariable logistic regression analysis showed that the use of nefopam was not associated with a higher incidence of PONV (adjusted odds ratio, 1.616; 95% confidence interval, 0.952–2.743, P = 0.076). There were no differences in postoperative pain scores between the two groups.

Conclusion

The combined use of nefopam with fentanyl in IV PCA was not associated with the higher incidence of PONV compared with the use of ketorolac and fentanyl combination in patients who received ramosetron as PONV prophylactic agent. However, prospective trials are required for a confirmative conclusion.

Median effective dose of nefopam to treat postoperative pain in patients who have undergone laparoscopic cholecystectomy

Objective

Nefopam is thought to reduce postoperative pain; however, the evidence is insufficient. The recommended dose is 20 mg, and the median effective dose (ED50) in the surgical setting reportedly ranges from 17 to 28 mg. However, nefopam frequently produces inadequate postoperative analgesia. We evaluated the ED50 of nefopam as a single agent in patients undergoing laparoscopic cholecystectomy.

Methods

Twenty-nine patients were scheduled for laparoscopic cholecystectomy. Postoperative pain was evaluated using a numerical pain scale (NPS). When the NPS score was >3, patients were administered a predetermined dose of nefopam. The dose was calculated using the up-and-down allocation technique based on the previous response. The initial dose was 28 mg, with adjustment intervals of 5 mg. An effective response was defined as a decrease in the NPS score to <3 at 30 minutes after infusion.

Results

The ED50 of nefopam was 62.1 mg (95% confidence interval, 52.9–72.9 mg). Eight patients reported pain upon injection, and three were excluded due to severe injection pain and phlebitis.

Conclusions

The estimated ED50 was higher than the predetermined dose based on previous studies. We recommend that the dose of nefopam be chosen after careful consideration of individual variations and clinical settings.

Intraoperative Nefopam Reduces Acute Postoperative Pain after Laparoscopic Gastrectomy: a Prospective, Randomized Study

BACKGROUND

We assessed whether intraoperative nefopam would reduce opioid consumption and relieve postoperative pain in patients undergoing laparoscopic gastrectomy.

METHODS

The 60 enrolled patients were randomly assigned to the control (n = 32) or nefopam (n = 28) group. All patients were blinded to their group assignment. We administered 100 ml of normal saline only (control group) or 20 mg of nefopam mixed in 100 ml normal saline (nefopam group) after anesthesia induction and at the end of surgery. The cumulative amount of fentanyl via intravenous patient-controlled analgesia (PCA), incidence of rescue analgesic medication, and numerical rating scale (NRS) for postoperative pain were evaluated along with the total remifentanil consumption.

RESULTS

The mean infusion rate of remifentanil was significantly lower in the nefopam group (0.08 ± 0.05 μg/kg/min) than in the control group (0.13 ± 0.06 μg/kg/min) (P < 0.001). Patients in the nefopam group required less fentanyl via intravenous PCA than those in the control group during the first 6 h after surgery (323.8 ± 119.3 μg vs. 421.2 ± 151.6 μg, P = 0.009). Additionally, fewer patients in the nefopam group than in the control group received a rescue analgesic during the initial 6 h postoperatively (78.6 vs. 96.9%, P = 0.028). The NRS measured while patients were in the post-anesthetic care unit was significantly lower in the nefopam group than in the control group (3.8 ± 1.1 vs. 4.8 ± 1.4, P = 0.012). The subsequent NRS obtained after patients had been transferred to the general ward was comparable between the two groups during the following postoperative period.

CONCLUSIONS

Intraoperative nefopam decreased postoperative pain and opioid consumption in the acute postoperative period after laparoscopic gastrectomy. Hence, nefopam may be considered as a component of multimodal analgesia after laparoscopic gastrectomy.

The efficacy and safety of nefopam for pain relief during laparoscopic cholecystectomy: A meta-analysis

BACKGROUND

Pain control after laparoscopic cholecystectomy (LC) has become an important topic. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of nefopam for pain management after LC.

METHODS

PubMed, Medline, Embase, ScienceDirect, and the Cochrane Library were searched up to November 2017 for comparative articles involving nefopam and placebo for reducing postoperative pain after LC. Primary outcomes were postoperative pain scores and opioid consumption. Secondary outcomes were length of hospital stay, opioid-related adverse effects, and postoperative complications. We assessed statistical heterogeneity for each RCT by using a standard Chi test and the I statistic. The meta-analysis was undertaken using Stata 12.0.

RESULTS

A total of 215 patients were analyzed across 4 RCTs. We found that there were significant differences between nefopam and placebo groups regarding the postoperative pain scores and opioid requirements at 6, 12, and 24 hours. Moreover, there was a decreased risk of opioid-related adverse effects in the nefopam groups. No significant differences were identified in terms of the incidence of postoperative complications.

CONCLUSION

Intravenous nefopam infusion resulted in significant reduction in postoperative pain scores and opioid requirements while decreasing opioid-related adverse effects. Additionally, no increased risk of venous thromboembolism was found. The current evidence suggests that more RCTs will be needed in further investigations.

Non-opioid pain management in benign minimally invasive hysterectomy: A systematic review

BACKGROUND

Less postoperative pain typically is associated with a minimally invasive hysterectomy compared with a laparotomy approach; however, poor pain control can still be an issue. Multiple guidelines exist for managing postoperative pain, yet most are not specialty-specific and are based on procedures that bear little relevance to a minimally invasive hysterectomy.

OBJECTIVE

The purpose of this study was to determine whether there is enough quality evidence within the benign gynecology literature to make non-opioid pain control recommendations for women who undergo a benign minimally invasive hysterectomy.

STUDY APPRAISAL AND SYNTHESIS METHODS

We queried PubMed, ClinicalTrials.gov, and Cochrane databases using MeSH terms: "postoperative pain," "perioperative pain," "postoperative analgesia," "pain management," "pain control," "minimally invasive gynecologic surgery," and "hysterectomy." A manual examination of references from identified studies was also performed. All PubMed published studies that involved minimally invasive hysterectomies through November 9, 2016, were included. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were restricted to benign minimally invasive hysterectomies evaluating non-opioid pharmacologic therapies. Primary outcomes included amount of postoperative analgesics consumed and postoperative pain scores. Two reviewers independently completed an in-depth evaluation of each study for characteristics and results using an established database, according to inclusion/exclusion criteria. A risk assessment was performed, and a quality rating was assigned with the use of the Cochrane Collaboration's Grades of Recommendation, Assessment, Development and Evaluation approach.

RESULTS

Initially 1155 studies were identified, and 24 studies met all inclusion criteria. Based on limited data of varying quality, intravenous acetaminophen, anticonvulsants and dexamethasone demonstrate opioid-sparing benefits; ketorolac shows mixed results in laparoscopic hysterectomies. Paracervical blocks provide pain-reducing benefits in vaginal hysterectomies.

CONCLUSIONS

Convincing conclusions are difficult to draw because of the heterogeneous and contradictory nature of the literature. There is a clear need for more high-quality research that will evaluate each medication type for posthysterectomy pain control.