A Systematic Review and Meta-analysis of the Analgesic Effects of Lidocaine Administered Intravenously or Intraperitoneally Post-Abdominal Surgery

BACKGROUND

Reducing postoperative pain is still a tremendous challenge for perioperative clinicians. Lidocaine is a local anesthetic that belongs to the amide class and has anti-inflammatory, anti-hyperalgesic, and analgesic effects. Extensive research has been conducted to determine the optimal route for its administration.

OBJECTIVE

To compare the efficacy of perioperative intravenous lidocaine with that of intraperitoneal lidocaine on postoperative analgesia in patients undergoing abdominal surgery.

STUDY DESIGN

EMBASE, PubMed, and The Cochrane Library were searched for randomized controlled trials published through December 2022 that compared patients receiving perioperative intravenous lidocaine with those receiving intraperitoneal lidocaine. The primary outcome measures included the pain score, as evaluated by the Visual Analog Scale, and opioid analgesia requirements. The secondary outcome measures were hospitalization length, gastrointestinal function recovery, etc. The data were acquired and recorded in electronic spreadsheets that had been designed for this purpose.

METHODS

This systematic review's design was based on the Cochrane Handbook for Systematic Reviews of Interventions and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method was used to examine the certainty of the evidence. Furthermore, we examined the dependability of the calculated (favorable) treatment effects through considerations of information size and modified significance thresholds (trial sequential analysis).

RESULTS

Seven trials including 478 patients were included. Our meta-analysis demonstrates that compared with intravenous lidocaine, patients who received intraperitoneal lidocaine had lower pain scores at 4 hours (mean difference [MD] 1.40; 95% CI, 0.22 to 2.59); 12 hours (MD 0.18; 95% CI, 0.06 to 0.30); and 24 hours (MD -0.12; 95% CI -0.40 to 0.17) postsurgery. However, no obvious difference in opioid consumption (P > 0.05) was found. In addition, the intraperitoneal lidocaine group had a longer postsurgery hospital stay than the intravenous lidocaine group (95%CI, -0.17 to -0.00; I2 = 0%). Intravenous lidocaine was more beneficial for achieving gastrointestinal return than intraperitoneal lidocaine (95% CI, -0.26 to -0.10; I2 = 2%).

LIMITATIONS

The sample size of enrolled RCTs was small, which could potentially result in an overestimation or underestimation of the treatment effect in the collected data. There was high heterogeneity among the studies.

CONCLUSION

This meta-analysis suggests that post-abdominal surgery intraperitoneal lidocaine administration has a better analgesic effect than intravenous lidocaine, with a lower pain score. However, intravenous lidocaine is more beneficial for gastrointestinal recovery after abdominal surgery.

Erector Spinae Plane Block versus Transversus Abdominis Plane Block for Robotic Inguinal Hernia Repair: A Blinded, Active-Controlled, Randomized Trial

BACKGROUND

Regional anesthetic nerve blocks are widely used in the treatment of pain after outpatient surgery to reduce opioid consumption. Erector spinae plane (ESP) block is a recently described technique with promising results in different scenarios.

OBJECTIVES

To compare ESP block efficacy with the commonly used transversus abdominis plane (TAP) block in patients undergoing robot-assisted inguinal hernia repair.

STUDY DESIGN

This was a randomized, blinded, active controlled, superiority trial with 2 parallel groups. The study was approved by the local ethics committee. Registration took place on; www.

CLINICALTRIALS

gov with the identifier NCT04750512.

SETTING

Adults undergoing robotic inguinal hernia repair were recruited between January 2021 and April 2022 in a single referral center of southern Switzerland.

METHODS

To ensure blinding, the study employed a "double dummy" design, where all patients underwent both TAP and ESP blocks, but only one block was therapeutically active. The therapeutic block contained ropivacaine 0.2%, while the other infiltration contained placebo. The therapeutic intervention varied between groups, with one group receiving the TAP block as the active treatment and the other group receiving the ESP block as the active treatment. Computer generated 1:1 randomization determined allocation, which took place immediately prior to the intervention. As a result, blinding included patients, anesthesia, and surgery providers, outcome assessors and statistical analysts. The main outcome measure was the highest reported pain score on a Visual Analog Scale (VAS) during the 6 hours following the end of general anesthesia. Secondary outcomes included pain scores at set intervals, analgesic consumption, and complications.

RESULTS

A total of 50 patients (25 per arm) were enrolled and included in the analysis. The study found no significant difference in the mean maximal VAS scores between the 2 groups (TAP block 22.2, ESP block 20, difference 2.2, 95% CI is -12.1 to 16.5). Secondary endpoints, including VAS pain scores at different time points, use of rescue analgesics, time to first walk, duration of stay, and frequency of adverse events, did not show any significant differences between the 2 groups. However, post-hoc analysis suggested a more stable effect over time for the ESP block compared to the TAP block.

LIMITATIONS

The main limitation is a higher variance in VAS scores than expected in the power calculations.

CONCLUSIONS

ESP block was not superior to TAP block in the treatment of post-operative pain among patients undergoing robotic inguinal hernia repair.

Effect of S-ketamine on Postoperative Pain in Adults Post-Abdominal Surgery: A Systematic Review and Meta-analysis

BACKGROUND

S-ketamine is the S-enantiomer of ketamine, which exerts anesthetic and analgesic effects through noncompetitive antagonism of N-methyl-D-aspartate (NMDA) receptors.

OBJECTIVE

We aimed to define the relative risk of post-abdominal surgery pain in adults who were administered perioperative S-ketamine.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Two reviewers independently screened the articles from the titles and abstracts based on our eligibility criteria, evaluated the risk of bias by using the Cochrane Collaboration Risk of Bias tool in randomized controlled trials, and extracted the data from the included studies according to a prespecified protocol; any disagreements were solved by consultation. The level of certainty for the main results were evaluated according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

Of the 1,621 studies identified, 9 studies were included; they were published from 2004 through 2022. Only one study involved epidural anesthesia, whereas the other 8 studies included general anesthesia. The pain at rest scores at 4 and 24 hours post-abdominal surgery were significantly lower in the S-ketamine group, respectively. However, there was no significant difference between the 2 groups in the pain at rest scores at 48 hours post-abdominal surgery. S-ketamine infusion reduced pain during movement 24 hours post-abdominal surgery, but not at 48 hours, respectively. The incidence of postoperative nausea and vomiting, as well as psychotomimetic adverse effects post-abdominal surgery were similar between the 2 groups, respectively. A subgroup analysis revealed that the pain at rest score at 4 hours post-abdominal surgery in patients in the intraoperative use group was remarkably reduced, compared with the patients who received S-ketamine perioperatively. Otherwise, the pain at rest score at 24 hours post-abdominal surgery in the perioperative use group was significantly reduced versus intraoperative use group.

LIMITATION

The number of trials included was small. The remarkable heterogeneity found in the pooled results at each time point post-abdominal surgery might affect the credibility of the results.

CONCLUSIONS

S-ketamine is effective in reducing the early postoperative pain of patients who received abdominal surgery, and may not increase the incidence of postoperative complications.

Comparison of Intercostal Block and Epidural Analgesia for Post-thoracotomy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Thoracotomy is associated with severe postoperative pain. Effective management of acute pain after thoracotomy may reduce complications and chronic pain. Epidural analgesia (EPI) is considered the gold standard for postthoracotomy analgesia; however, it is associated with complications and limitations. Emerging evidence suggests that an intercostal nerve block (ICB) has a low risk of severe complications. Anesthetists will benefit from a review that assesses the advantages and disadvantages associated with ICB and EPI in thoracotomy.

OBJECTIVES

This meta-analysis aimed to evaluate the analgesic efficacy and adverse effects of ICB and EPI for pain treatment after thoracotomy.

STUDY DESIGN

Systematic review.

METHODS

This study was registered in the International Prospective Register of Systematic Reviews (CRD42021255127). Relevant studies were searched for in PubMed, Embase, Cochrane, and Ovid databases. Primary (postoperative pain at rest and during cough) and secondary (nausea and vomiting, morphine consumption, and length of hospital stay) outcomes were analyzed. The standard mean difference for continuous variables and the risk ratio for dichotomous variables were calculated.

RESULTS

Nine randomized controlled studies with a total of 498 patients who underwent thoracotomy were included. The results of the meta-analysis demonstrated no statistically significant differences between the 2 methods in terms of the Visual Analog Scale scores for pain at 6-8, 12-15, 24-25, and 48-50 hours at rest and at 24 hours during coughing after surgery. There were no significant differences in nausea and vomiting, morphine consumption, or length of hospital stay between the ICB and EPI groups.

LIMITATIONS

The number of included studies was small, and the quality of evidence was low.

CONCLUSIONS

ICB may be as effective as EPI for pain relief after thoracotomy.

Regional Analgesia for Laparoscopic Cholecystectomy Using Ultrasound-guided Quadratus Lumborum Block or Erector Spinae Block: A Randomized Controlled Trial

BACKGROUND

Postoperative pain increases the incidence of venous thrombosis and respiratory complications, prevents early postoperative ambulation, and prolongs hospital stay. Fascial plane injections such as erector spinae plane (ESP) block and quadratus lumborum (QL) blocks are popular methods for postoperative pain control and reducing opioid consumption.

OBJECTIVES

We aimed to evaluate the analgesic effects of ultrasound-guided ESP versus QL block during laparoscopic cholecystectomy for the reduction of pain and analgesic consumption.

STUDY DESIGN

Prospective, double-blind, single-center, randomized controlled clinical trial.

SETTING

Minia University Hospital, Minia Governorate, Egypt.

METHODS

Patients scheduled for laparoscopic cholecystectomy from April 2019 through December 2019 were randomly allocated into 3 groups. After induction of general anesthesia, Group A received an ESP block, group B received a QL block, and group C didn't receive any block (control). The main outcome was the time to the first analgesic request. Secondary outcomes were the pain intensity measured by the Visual Analog Scale at one, 2, 4, 6, 8, 12, 16, 20, and 24 hours postoperatively at rest and cough. The total analgesic requirement during the first 24 postoperative hours, hemodynamics, and any complications were recorded.

RESULTS

Sixty patients scheduled for elective laparoscopic cholecystectomy were enrolled; the clinical and demographic data were similar in the 3 groups. Groups A and B had lower VAS scores at cough than Group C in the first postoperative 2 hours. Compared to Group C, a higher score was reported at 8, 12, and 16 hours in Group A, and at 8 and 16 hours in Group B. Group B had a higher score at 4 hours than Group A. At rest, Group C showed higher scores than Groups A and B in the first 2 hours, while higher scores were noted at 16 hours in Group A and 12 hours in Group B. Time to first request of analgesia was significantly prolonged in Group A than in Groups B and C (P < 0.001). Our study showed that Groups A and B had lower postoperative analgesic requirements than Group C (P < 0.05).

LIMITATIONS

This study had a small number of patients enrolled.

CONCLUSIONS

Both ESP and QL blocks effectively reduced VAS scores at both cough and rest. There was a decreased total consumption of analgesics in the first postoperative 24 hours with a longer duration of analgesia, which lasted 16 hours in the ESP group and 12 hours in the QL group.

Does the Choice of Operative Side Affect the Clinical Outcome of Unilateral Percutaneous Kyphoplasty for Osteoporotic Vertebral Compression Fracture?

BACKGROUND

Studies have found that the rate of improvement in pain after percutaneous kyphoplasty (PKP) is 49% to 90%, and there are still some patients who may continue to sustain intractable back pain after surgery.

OBJECTIVES

To compare the clinical efficacy and imaging results between unilateral PKP performed from the symptom-dominating side and the non-dominating side in OVCF treatment.

STUDY DESIGN

Prospective study.

SETTING

All data were from Honghui Hospital in Xi'an.

METHODS

One hundred forty-two patients of osteoporotic vertebral compression fracture (OVCF) treated with unilateral PKP were eventually recruited and randomly assigned to either the A or B group. Patients in group A received PKP from the symptom-dominating side; patients in group B received PKP from the symptom non-dominating side. The demographic characteristics, related surgical information, and complications observed within both groups were recorded. The clinical outcomes evaluation included the visual analog scale (VAS) score for low back pain and the Oswestry Disability Index (ODI). Evaluation of imaging results included anterior height (AH), kyphosis angulation (KA), and contralateral distribution rate of bone cement.

RESULTS

One hundred eighteen patients (48 men and 70 women; age range: 60-83 years), including 59 patients in the A group and 59 patients in the B group, were available for the complete assessment. There were 5 cases and 7 cases of bone cement leakage in groups A and B, respectively, which were asymptomatic para-vertebral or inter-vertebral leakage without intra-spinal leakage. Compared with the preoperative data, significant improvements in the VAS scores and ODI were observed at each follow-up interval. The VAS score and ODI in the A group were significantly lower than in the B group only within 2 months (P < 0.05). Compared with the preoperative data, the AH and KA in the 2 groups were improved (P < 0.05). There was no significant difference in AH and KA between the 2 groups at each follow-up interval (P > 0.05).

LIMITATIONS

A single-center study.

CONCLUSIONS

The unilateral PKP performed via the symptom-dominating side can effectively relieve back pain and improve the patient's quality of life at the early stage.

Erector spinae plane block, neuropathic pain and quality of life after video-assisted thoracoscopy surgery. Pilot, observational study

BACKGROUND

The erector spinae plane block (ESPB) is a valuable alternative for pain management after video-assisted thoracoscopy surgery (VATS). The incidence of postoperative chronic neuropathic pain (CNP) is high while the quality of life (QoL) after VATS remains unknown. We hypothesised that patients with ESPB would have a low incidence of acute and CNP and would report a good QoL up to three months after VATS.

METHODS

We conducted a single-centre prospective pilot cohort study from January to April 2020. ESPB after VATS was the standard practice. The primary outcome was the incidence of CNP three months postoperatively. Secondary outcomes included QoL assessed by the EuroQoL questionnaire three months after surgery and pain control at the Post-Anaesthesia Care Unit (PACU), 12 and 24 hours postoperatively.

RESULTS

We conducted a single-centre prospective pilot cohort study from January to April 2020. ESPB after VATS was the standard practice. The primary outcome was the incidence of CNP three months postoperatively. Secondary outcomes included QoL assessed by the EuroQoL questionnaire three months after surgery and pain control at the Post-Anaesthesia Care Unit (PACU), 12 and 24 hours postoperatively.

CONCLUSIONS

We conducted a single-centre prospective pilot cohort study from January to April 2020. ESPB after VATS was the standard practice. The primary outcome was the incidence of CNP three months postoperatively. Secondary outcomes included QoL assessed by the EuroQoL questionnaire three months after surgery and pain control at the Post-Anaesthesia Care Unit (PACU), 12 and 24 hours postoperatively.

Continuous lumbar erector spinae plane block as an alternative to epidural analgesia in pain treatment in patients undergoing hip replacement surgery - a prospective pilot study

INTRODUCTION

Postoperative pain associated with hip replacement surgery can be severe, decreasing the patient's mobility and satisfaction with perioperative treatment. Regional techniques are commonly used as postoperative analgesia in hip surgery patients.

MATERIAL AND METHODS

We performed a prospective pilot study on patients undergoing hip replacement surgery. We anesthetized each participant with spinal technique and allocated patients according to postoperative analgesia to the continuous epidural group and the continuous lumbar erector spinae plane block (ESPB) group. We measured postope-rative oxycodone consumption with patient-controlled analgesia (PCA) demands. At several points, we evaluated the patients' pain at rest and during activity on the visual analog scale (VAS, 0-10), their quadriceps femoris' muscle strength on the Lovett scale (0-5), and their ability to sit, stand upright, and walk on the Timed Up and Go test. Moreover, we assessed the patients' recovery through the Quality of Recovery 40 (QoR-40) questionnaire on the first postoperative day.

RESULTS

We found lower oxycodone consumption via PCA in the epidural than in the ESPB group (9.1 (mean) mg (5.2-13.0) (confidence interval) vs. 15.5 mg (9.8-21.3), P = 0.049). Patients in the ESPB group had more demands with PCA than participants in the epidural group (10.5 (median) (6-16) (interquartile range) vs. 25 (16-51), P = 0.016). We did not find differences between the groups in the other outcomes or in terms of postoperative complications.

CONCLUSIONS

The results suggest that the continuous lumbar ESPB group is equivalent to epidural analgesia as a pain treatment technique in patients undergoing hip replacement surgery.

Does Intraoperative Multi-Drug Wound Infiltration Relieve Postoperative Pain Following Single-Level TLIF Surgery? A Randomized Controlled Trial

BACKGROUND

How to minimize postoperative pain following spinal surgery has been a great challenge for both surgeons and patients. We hypothesized that intraoperative multi-drug wound infiltration could relieve postoperative pain following single-level transforaminal lumbar interbody fusion (TLIF) surgery.

OBJECTIVES

To evaluate the effect of intraoperative multi-drug wound infiltration for postoperative pain following single-level TLIF surgery.

STUDY DESIGN

A randomized, double-blinded controlled trial (RCT).

SETTING

Department of Orthopaedic Surgery, Qilu Hospital of Shandong University.

METHODS

The RCT enrolled 50 patients with 25 cases in 2 groups. The study group received intraoperative wound infiltration of mixed solution with lidocaine, ropivacaine, and epinephrine before wound closure. The control group was infiltrated with an equal amount of normal saline. The primary outcome measure was the visual analog scale (VAS) of postoperative incision pain. The secondary outcome measures were the postoperative opioids dosage, the time of first analgesic demand, and the Oswestry Disability Index (ODI).

RESULTS

The VAS of postoperative pain in the study group was significantly lower than the control group within postoperative 24 hours. The opioid dosage was significantly less and the time of first analgesic demand of patient-controlled analgesia (PCA) in the study group was significantly longer than the control group. None of the patients in the study group required analgesic supplementation. The side effects of opioids were significantly less in the study group. There was no significant difference in ODI, operation time, intraoperative blood loss, postoperative drainage, and postoperative incision complications between the 2 groups.

LIMITATIONS

Single-center study for single-level TLIF surgery.

CONCLUSIONS

Intraoperative multi-drug wound infiltration before closure could significantly relieve postoperative pain following single-level TLIF surgery.

Effect of Continuous Infusion of Intravenous Nefopam on Postoperative Opioid Consumption After Video-assisted Thoracic Surgery: A Double-blind Randomized Controlled Trial

BACKGROUND

Although nefopam has been reported to have opioid-sparing and analgesic effects in postsurgical patients, its effectiveness in video-assisted thoracoscopic surgery (VATS) is unknown.

OBJECTIVES

This study aimed to investigate the opioid-sparing and analgesic effects of perioperative nefopam infusion for lung resection.

STUDY DESIGN

Double-blinded randomized controlled trial.

SETTING

Operating room, postoperative recovery room, and ward at a single tertiary university hospital.

METHODS

Ninety patients scheduled for elective VATS for lung resection were randomized to either the nefopam (group N) or control group (group C). Group N received 20 mg nefopam over 30 minutes immediately after the induction of anesthesia. Nefopam was administered continuously for 24 hours postoperative, using a dual-channel elastomeric infusion pump combined with fentanyl-based intravenous patient-controlled analgesia. Group C received the same volume of normal saline as nefopam solution administered in the same manner. The primary outcome measure was fentanyl consumption for the first postoperative 24 hours. The secondary outcome measures were the cumulative fentanyl consumption during the first postoperative 48 hours, pain intensity at rest and during coughing evaluated using an 11-point numeric rating scale, quality of recovery at postoperative time points 24 hours and 48 hours, and the occurrence of analgesic-related side effects during the first postoperative 24 hours and postoperative 24 to 48 hour period. Variables related to chronic postsurgical pain (CPSP) were also investigated by telephone interviews with patients at 3 months postoperative. This prospective randomized trial was approved by the appropriate institutional review board and was registered in the ClinicalTrials.gov registry.

RESULTS

A total of 83 patients were enrolled. Group N showed significantly lower fentanyl consumption during the first postoperative 24 hours and 48 hours (24 hours: median difference: -270 µg [95%CI, -400 to -150 µg], P < 0.001); 48 hours: median difference: -365 µg [95% CI: -610 to -140 µg], P < 0.001). Group N also showed a significantly lower pain score during coughing at 24 hours postoperative (median difference, -1 [corrected 95% CI: -2.5 to 0], adjusted P = 0.040). However, there were no significant between-group differences in the postoperative quality of recovery, occurrence of analgesic-related side effects, length of hospital stay, and occurrence of CPSP.

LIMITATIONS

Despite the significant opioid-sparing effect of perioperative nefopam infusion, it would have been difficult to observe significant improvements in other postoperative outcomes owing to the modest sample size.

CONCLUSION

Perioperative nefopam infusion using a dual-channel elastomeric infusion pump has a significant opioid-sparing effect in patients undergoing VATS for lung resection. Therefore, it could be a feasible option for multimodal analgesia in these patients.

Postoperative Pain in Adolescent Idiopathic Scoliosis Surgery: A Randomized Controlled Trial

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis, and its treatment is essentially surgical for curves above 40 degrees. Posterior spinal instrumentation (PI) is the usual technique, while the vertebral body tethering (VBT) method is tested technique for this study as a new treatment option.

OBJECTIVES

To compare postoperative pain outcomes between PI and VBT with mini-thoracotomy surgeries performed in AIS patients.

STUDY DESIGN

Prospective, randomized controlled study registered with the Clinical Trials Portal (NCT04822935).

SETTING

Department of Anesthesiology.

METHODS

We randomly divided 31 adolescents (28 women, 3 men) aged 11 to 18, with a diagnosis of AIS into 2 groups using computer software: the PI and the VBT groups. Postoperative morphine consumption and the Numeric Pain Rating Scale (NRS) scores at the 1st, 4th, 8th, 12th, 24th, and 48th hours and at 4 weeks were recorded. Length of hospital stays, length of intensive care unit (ICU) stays, duration of operation, postoperative patient satisfaction with the Likert scale, and complications such as bleeding and respiratory distress were recorded. Preoperative and follow-up Oswestry Disability Index (ODI) questionnaires were obtained to assess patient outcomes at 4 weeks postoperatively.

RESULTS

Postoperative morphine consumption and the NRS scores at the 1st, 4th, 8th, 12th, 24th, and 48th hours were significantly higher in group VBT (P < 0.05). The amount of bleeding was significantly higher in group PI (P = 0.002). The ICU and the hospital length of stays in the VBT group were significantly higher (respectively, P = 0.011; P = 0.032). Discharge NRS scores, ODI scores as well as patients' satisfaction were similar in both groups (P > 0.05).

LIMITATIONS

Firstly, this was a single-centered study with a small sample owing to the rarity of AIS surgeries. Moreover, double-blinding was not applied to the patients and doctors because of the surgery incision places.

CONCLUSION

From our results, both techniques can be employed for AIS surgery, but a meticulous approach is essential for the prevention of acute pain for VBT.

Effect of Intravenous Dexamethasone on Postoperative Pain in Patients Undergoing Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative pain after total knee arthroplasty (TKA) is intense and remains an unsolved problem. Some studies show that perioperative, multimodal analgesia, including intravenous dexamethasone, can provide a better analgesic effect; however, the validity of studies has raised concerns and questions remain around the efficacy, dosing, and safety of dexamethasone in patients undergoing total knee arthroplasty.

OBJECTIVES

The purpose of this systematic review and meta-analysis was to evaluate the impact of intravenous dexamethasone on postoperative pain among patients undergoing TKA.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING

Web of Science, Embase, PubMed, and the Cochrane Central Register of Controlled Trials were searched to identify relevant randomized controlled trials. The last search was in August 2021.

METHODS

The risk of bias of the included trials was assessed by the Cochrane Risk of Bias Tool. The primary outcome was postoperative visual analog scale (VAS) pain scores and secondary outcomes included cumulative equivalent intravenous morphine consumption, number of patients requiring rescue analgesic, length of hospital stay, and adverse events. We assessed the certainty of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Eleven studies with 1,671 patients were included. The pooled results indicated that patients receiving dexamethasone had lower VAS pain scores at rest (24 h, MD = -0.68, [95% CI: -0.87 to -0.49]; 48 h, MD = -0.33, [95% CI: -0.46 to -0.21]) and at movement (24 h, MD = -0.74, [95% CI: -1.10 to -0.37]; 48 h, MD = -0.46, [95% CI: -0.66 to -0.26]), required less morphine (24 h, MD = -2.84 mg, [95% CI: -5.13 to -0.54]; 48 h, MD= -4.16 mg, [95% CI: -5.55 to -2.78]) and rescue analgesics, and had shorter hospitalization. There was no increase in infection, gastrointestinal hemorrhage, wound healing problems, or blood glucose levels with dexamethasone. Subgroup analysis did not observe difference between single dose and repeat dose groups.

LIMITATIONS

The perioperative multimodal analgesia measures were varied throughout the studies. The sample size was small for some outcomes and high heterogeneity was observed.

CONCLUSIONS

Our results supported the addition of perioperative intravenous dexamethasone to multimodal analgesia in total knee arthroplasty to reduce postoperative pain, opioids consumption, and length of hospital stay. Current evidence did not support the superiority of repeated-dose dexamethasone over single-dose dexamethasone; thus, we recommended perioperative 8-10 mg intravenous dexamethasone to be used based on adequate basic analgesia; however, the results may have been affected by small sample sizes and heterogeneity.

Identification of Preoperative Serum Metabolites Associated With Postoperative Opioid Consumption in Gastric Cancer Patients by Extreme Phenotype Sampling

BACKGROUND

Postoperative pain increases patients' risk and opioids remain the main analgesics to relieve it. However, improper use of opioids causes many side effects and identification of suitable preoperative biomarkers that predict postoperative opioid consumption may aid clinicians in improving analgesic strategies for patients. The activity of metabolites modulates multiple phenotypes and can function as biomarkers for disease prediction and diagnosis.

OBJECTIVES

In this study, we explore whether preoperative serum metabolites are associated with postoperative opioid consumption in gastric cancer patients by extreme phenotype sampling.

STUDY DESIGN

This was a case-control, observational study.

SETTING

This study was conducted at Beijing Cancer Hospital.

METHODS

One hundred and sixty-nine gastric cancer patients participated in this study. After exclusion of 51 patients, postoperative pain intensity and opioid consumption data of 118 patients were collected. Patients were sorted by gender and classified into 2 groups based on opioid consumption during the 24h postoperative period. Patients in the sufentanil high consumption (SHC) group and patients in the sufentanil low consumption (SLC) group were ranked in the top or bottom 30% of sufentanil consumption, respectively. Untargeted metabolomic analysis of preoperative serum samples from both groups was performed by ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and orthogonal partial least square discriminant analysis. Allele frequencies of DAO rs10156191 and MAOB rs1799836 SNPs in both groups were detected by Sanger sequencing.

RESULTS

Thirty-five metabolites in preoperative serum were significantly different between the SLC and SHC groups. Hydrogen phosphate had the highest area under the curve in a ROC analysis (0.98), suggesting that it may serve as a predictive biomarker for postoperative opioid consumption. Differential metabolites unique to the male and female subgroups were also identified. Histidine metabolism was the most altered pathway between the SLC and SHC groups. There were no significant differences in the allele frequencies of 2 SNPs associated with histamine degradation; however, 2 metabolites of histamine degradation, imidazole-4-acetaldehyde, and methylimidazole acetaldehyde, showed different trends in the 2 groups.

LIMITATIONS

Our study was restricted to gastric cancer patients with strict exclusion criteria, which may limit the generalizability to other groups.

CONCLUSION

Preoperative serum metabolites were associated with postoperative opioid consumption. Different efficiencies of histamine degradation may be one cause of the variable sensitivity of patients to acute pain and warrants further study.

Efficacy of type-I and type-II pectoral nerve blocks (PECS I and II) in patients undergoing mastectomy: a prospective randomised clinical trial

INTRODUCTION

The benefits of type I/II pectoral nerve blocks (PECS I/II), which can be dose dependent, have been examined in different studies. Nonetheless, few randomised trials have been performed in South America. The present randomised trial examined the efficacy of PECS I/II with a higher dose of the local anaesthetic to manage perioperative pain after mastectomy in Brazil.

MATERIAL AND METHODS

This was a randomised, parallel, single-centre, and single-blind trial. Eighty participants undergoing elective mastectomy were randomised (1 : 1) to receive PECS I/II plus ultrasound-guided ropivacaine (0.5%) or standard general anaesthesia. The primary outcome was pain intensity at rest 24 hours after surgery, assessed with a numerical rating scale. Haemodynamic outcomes, consumption of opioids, anaesthe-tics and antiemetics, and post-anaesthetic recovery times were also recorded.

RESULTS

Sixty participants (75%) completed the study. The mean age was 54 years, with 57% of participants undergoing mastectomy and 43% undergoing quadrantectomy. Median pain intensity (interquartile range) at rest (24 h postoperatively) was lower in the PECS I/II group compared to the control group: 0 (0-1.75) vs. 1 (1-2), P = 0.021. A smaller number of patients in the PECS I/II group required intraoperative fentanyl (23.3% vs. 83.3%; P < 0.001) and postoperative tramadol (20.0 vs. 76.7%; P < 0.001). Mean doses of fentanyl and tramadol were about 4-5 times lower in the PECS I/II group (P < 0.001). PECS I/II significantly reduced sevoflurane consumption during surgery (P = 0.01). No difference was observed regarding adverse effects.

CONCLUSIONS

PECS I/II blockade with high-dose local anaesthetic is efficacious and safe, resulting in lower levels of perioperative pain after mastectomy compared to standard general anaesthesia.

Patterns of Use of Opioid Sparing Adjuncts for Perioperative Pain Management of Patients on Chronic Opioids

BACKGROUND

Perioperative pain management of patients on chronic opioids is challenging. Although experts recommend regional anesthesia and multimodal analgesics for their opioid sparing effects, their use and predictors of use are unknown.

OBJECTIVES

To examine the patterns and predictors of use of regional anesthesia and multimodal analgesics for perioperative pain control of patients on chronic opioids. A secondary objective was to examine the association of patient and surgical factors with 24-hour postoperative opioid use.

STUDY DESIGN

Retrospective cross sectional.

SETTING

Single center tertiary care academic hospital.

METHODS

We studied patients with chronic opioid use undergoing painful operations such as abdominal, gynecologic, breast, orthopedic, spine, amputation, and laparoscopic surgeries. Chronic opioid use was identified using the narcotic score - a score generated from the state prescription drug monitoring database via the NarxCare platform. A narcotic score >= 320 corresponding to a preoperative home dose of approximately 40 milligram morphine equivalents (MMEs) daily, was chosen as a cutoff since the risk of overdose death increases above 40 MMEs. We reported the use of regional anesthesia and >= 3 multimodal analgesics in this cohort (n = 155) and examined the association of this use with patient and surgical factors such as preoperative narcotic score, age, race, comorbidity index, operative timetime, and intraoperative opioid use. In addition, we examined the association of patient and surgical factors with 24-hour postoperative opioid use.

RESULTS

Out of 2470 patients undergoing painful surgeries between July 2017and- December 2018, 155 patients had a narcotic score >= 320. The median narcotic score was 411 (interquartile range (IQR) 351-520), the median preoperative home MME dose was 67.5 (IQR 32-180) mg daily. Regional anesthesia was used in only 9.7% of cases and was associated with intraoperative opioid used, but not the preoperative narcotic score. Patients receiving 1 SD more MMEs intraoperatively had a higher odds of receiving regional anesthesia (OR = 1.57, 95% CI [1.06, 2.32]). Three or more multimodals were used in 83% of cases. Every 10-point increase in narcotic score and every additional hour of operative time was associated with higher odds of receiving >= 3 multimodals (OR = 1.05, 95% CI [1.00, 1.11] and OR = 1.49, 95% CI [1.11, 1.99] respectively). Total 24 hour post-operative opioid dose was associated with narcotic score, with an 8.6 higher mean MME for every 10-point increase in narcotic score (mean difference = 8.6, 95% CI [4.1, 13.1]). It was also moderately associated with age, where patients an year older received 4.7 MMEs less (mean difference = - 4.7, 95% CI [-9.3, -0.5]).

LIMITATIONS

This was a single center retrospective observational study. We could not adjust for inter-physician or inter-surgery effect on use of regional anesthesia or multimodal analgesics. Since this was one of the first studies to use narcotic scores to identify patients on chronic opioids, comparing the outcomes of interest to a control group was beyond the scope of the current study. Narcotic scores need to be validated to identify chronic opioid use.

CONCLUSIONS

Despite consensus guidelines, regional anesthesia remains underutilized. Multimodals are used frequently and are modestly associated with preoperative narcotic scores.

Effects of Intravenous Dexmedetomidine Versus Lidocaine on Postoperative Pain, Analgesic Consumption and Functional Recovery After Abdominal Gynecological Surgery: A Randomized Placebo-controlled Double Blind Study

BACKGROUND

The management of acute postoperative pain remains challenging, and the search for adjuvants to reduce opioid use continues.

OBJECTIVES

We studied the effect of intravenous dexmedetomidine and lidocaine on postoperative pain, opioid consumption, and functional recovery.

STUDY DESIGN

A randomized controlled trial was performed.

SETTING

The trial was conducted at Aretaieio University Hospital, Athens, Greece.

METHODS

In this double-blind study, 91 women, 30-70 years old, with an American Society of Anesthesiologists Physical Status of I or II, scheduled for abdominal hysterectomy or myomectomy, were randomized to receive either dexmedetomidine (DEX group), lidocaine (LIDO group), or placebo (CONTROL group). Before anesthesia induction, a loading intravenous dose of one of the aforementioned drugs was given to all patients (0.9mL/kg/h for 10 minutes), followed by 0.15mL/kg/h infusion until the last suture. Identical 50 mL syringes containing dexmedetomidine 4 mg/mL (bolus: 0.6 µg/kg, infusion: 0.6 µg/kg/h), or lidocaine 10 mg/mL (bolus: 1.5 mg/kg, infusion: 1.5 mg/kg/ h), or NaCl 0.9% were used. The main outcomes were cumulative morphine consumption and postoperative pain at rest and cough (Numeric Rating Scale, [NRS]: 0-10). Other measurements included anesthetic (sevoflurane) consumption, nausea/vomiting, postoperative sedation, time to first passage of flatus/stool, mobilization, sleep quality, satisfaction, discharge time, and drug side effects. Measurements were performed at Post-anesthesia Care Unit (PACU), 2 hours, 4 hours, 8 hours, 24 hours, and 48 hours.

RESULTS

Data from 81 patients were analyzed (DEX group:26, LIDO group:29, CONTROL group:26). Cumulative morphine consumption (mg) was significantly lower in the LIDO group versus the CONTROL group in the PACU (LIDO group: 8.41 ± 1.45, CONTROL group: 10.4 ± 3.29, P = 0.017); at 24 hours (LIDO group: 16.86 ± 5.85, CONTROL group: 23.4 ± 9.54, P = 0.036); and 48 hours (LIDO group: 20.45 ± 6.58, CONTROL group: 28.87 ± 12.55, P = 0.022). The DEX group experienced significantly less nausea compared to the CONTROL group in the PACU (P = 0.041). Finally, the use of vasoconstrictors was higher in the treatment groups, especially in the DEX group compared to the CONTROL group (P = 0.012). The rest of the measurements regarding NRS scores, sevoflurane consumption, bowel function, and other recovery characteristics, satisfaction, discharge time, and drug side effects did not differ significantly among the groups.

LIMITATIONS

Different doses of the studied medications were not assessed, drugs were administered only pre- and intraoperatively, and pain was not managed according to the World Health Organization (WHO) pain relief ladder. However, all patients were adequately covered with patient-controlled anesthesia morphine and acetaminophen; parecoxib (not approved for use in the United States) was preserved as a rescue analgesic.

CONCLUSIONS

Dexmedetomidine and lidocaine could be useful adjuvants for analgesia after abdominal surgery. Lidocaine significantly reduced postoperative opioid consumption, while dexmedetomidine prevented early postoperative nausea. However, hypotension and the need for vasopressors was common with both agents, especially with dexmedetomidine.

The Added Value of Sensitivity to Nonnoxious Stimuli to Predict an Individual's Sensitivity to Pain

BACKGROUND

Simple tools are needed to predict postoperative pain. Questionnaire-based tools such as the Pain Sensitivity Questionnaire (PSQ) are validated for this purpose, but prediction could be improved by incorporating other parameters.

OBJECTIVES

To explore the potency of sensitivity to nonpainful stimuli and biometric data to improve prediction of pain.

STUDY DESIGN

Transversal exploratory study.

SETTING

Single clinical investigation center.

METHODS

Eighty-five healthy volunteers of both genders underwent a multimodal exploration including biometry, questionnaire-based assessment of anxiety, depression, pain catastrophizing, sensitivity to smell, and the PSQ, followed by a psychophysical assessment of unpleasantness thresholds for light and sound, and sensitivity to mechanical, heat, and cold pain. These last 3 parameters were used to calculate a composite pain score. After a multi-step selection, multivariable analyses identified the explanative factors of experimental pain sensitivity, by including biometric, questionnaire-based, and psychophysical nonnociceptive sensitivity parameters, with the aim of having each domain represented.

RESULTS

Female gender predicted mechanical pain, a younger age and dark eyes predicted cold pain, and the PSQ predicted heat pain. Sensitivity to unpleasantness of sound predicted mechanical and heat pain, and sensitivity to unpleasantness of light predicted cold pain. Sensitivity to smell was unrelated. The predictors of the composite pain score were the PSQ, the light unpleasantness threshold, and an interaction between gender and eye color, the score being lower in light-eyed men and higher in all women. The final multivariable multi-domain model was more predictive of pain than the PSQ alone (R2 = 0.301 vs 0.122, respectively).

LIMITATIONS

Sensitivity to smell was only assessed by a short questionnaire and could lack relevance. Healthy volunteers were unlikely to elicit psychological risk factors such as anxiety, depression, or catastrophizing. These results have not been validated in a clinical setting (e.g., perioperative).

CONCLUSION

The predictive potential of the PSQ can be improved by including information about gender, eye color, and light sensitivity. However, there is still a need for a technique suitable for routine clinical use to assess light sensitivity.

Quadratus Lumborum Block is an Effective Postoperative Analgesic Technique in Pediatric Patients Undergoing Lower Abdominal Surgery: A Meta-Analysis

BACKGROUND

Quadratus lumborum (QL) block has shown promising analgesic efficacy in the adult population in previous meta-analyses. However, the response of the pediatric group to pain stimulation is stronger than that in the adult population, and the management of pediatric pain is constrained by limited available analgesia agents. All data analyzed during this study are collected from published articles.

OBJECTIVE

The purpose of our systematic review was to evaluate whether QL block is also an effective postoperative analgesic technique, compared to other analgesic skills in pediatric patients undergoing lower abdominal surgery.

STUDY DESIGN

A meta-analysis.

METHODS

We identified randomized controlled trials (RCTs) from PubMed, Embase, the Cochrane Library, Web of Science, and Science Direct to compare QL block with other analgesic methods for relief of postoperative pain in pediatric patients undergoing lower abdominal surgeries under general anesthesia. The primary outcome was the rate of postoperative rescue analgesia; secondary outcomes include: pain scores at 30 minutes and 1, 2, 4, 6, 12, and 24 hours postoperatively, patient satisfaction, and block related complications.

RESULTS

A total of 7 studies with 346 patients were included. QL block showed a significant reduction in the rate of postoperative rescue analgesia in the first 24 hours (RR = 0.41; 95% CI = 0.28 to 0.59; P < 0.001) compared to other analgesic techniques, without significant heterogeneity among the articles (I2 = 49%, P = 0.08). Compared with other analgesic methods, QL block significantly reduced the pain scores at 2 hours (Std.MD = -0.76; 95% CI = -1.16 to -0.35; P < 0.001) (I2 < 0.001%, P = 0.41), 4 hours (Std.MD = -0.34; 95% CI = -0.67 to -0.01; P = 0.04) (I2 < 0.001%, P = 0.53) and 12 hours postoperatively (Std.MD = -0.95; 95% CI = -1.44 to -0.47; P < 0.001) (I2 = 27%, P = 0.24). No significant differences were found between techniques at 30 minutes and 1, 6, or 24 hours postoperatively (P > 0.05). There was no statistically significant change in patient satisfaction (Std.MD = 0.49; 95% CI = -0.32 to 1.29; P = 0.24) or side effects (RD = -0.02; 95% CI = -0.06 to 0.02; P = 0.31) with QL block.

LIMITATIONS

The major limitation of this meta-analysis is the relatively few RCTs and limited results included. Similarly, the differences in block approaches among the control groups (TAP, ESP, caudal block, opioid-based analgesia), drug types and concentrations, and multimodal analgesia programs led to considerable heterogeneity. Furthermore, some relevant outcomes were not investigated.

CONCLUSION

Our systematic review and meta-analysis suggests QL block use for the pediatric population undergoing lower abdominal surgery, based on the current limited research evidence, as this method was an effective postoperative analgesic technique.

Chronic Pregabalin Treatment and Oxycodone Requirement after Spinal Surgery Versus Short Course Perioperative Administration: A Prospective, Nonrandomized Study

BACKGROUND

Although being controversial, pregabalin (PGB) is proposed during a short perioperative period  to improve pain relief.Comparisons between chronic and short-term users during lumbar spine surgery are lacking.

OBJECTIVES

The purpose was to compare opioid requirements and postoperative pain among PGB chronic users and naive patients receiving a 48-hour perioperative administration.

STUDY DESIGN

Prospective nonrandomized study.

SETTING

Tertiary care hospital.

METHODS

Chronic users (group PGB, n = 39) continued their treatment, naive patients (group C, n = 43) received a dose of 150 mg preoperatively and 75 mg/12 hours for 48 hours. Anesthesia and analgesia were standardized. The primary outcome was the cumulative oxycodone consumption at 24 hours, other outcomes included pain scores, DN4 (Douleur Neuropathique 4 Questions) scores, and side effects.

RESULTS

Group PGB consumed less oxycodone at 24 hours (median [interquartile range] 10 mg [10-17.5] vs. 20 mg [10-20], P = 0.013], at 48 hours (15 mg [10-20] vs. 20 mg [12.5-30], P = 0.018), and required less intraoperative remifentanil (P = 0.004). Both groups showed similar pain scores during the 48-hour follow-up and at 3 months.Based on multivariate analysis, chronic users of PGB before surgery exhibited lower oxycodone requirements at 24 hours (odds ratio, 3.98; 95% confidence interval, 1.44-7.74; P = 0.008]. No differences were noted regarding side effects and DN4 scores.

LIMITATIONS

Nonrandomized study.

CONCLUSIONS

Patients chronically treated with PGB required less opioid when compared with a short perioperative administration before spinal surgery. Further prospective studies are required to confirm these results in spinal surgeries.

Gastrointestinal Adverse Events in Hospitalized Patients Following Orthopedic Surgery: Tapentadol Immediate Release Versus Oxycodone Immediate Release

BACKGROUND

Tapentadol has relatively less effect on mu-opioid receptors compared with other opioids. This has the potential to reduce the occurrence of gastrointestinal (GI) adverse drug events (ADEs).

OBJECTIVES

To compare the GI ADEs during hospitalization between tapentadol immediate release (IR) and oxycodone IR following orthopedic surgeries.

STUDY DESIGN

Retrospective cohort study.

SETTING

A major metropolitan tertiary referral hospital in Australia.

METHODS

Data for adult orthopedic surgery patients receiving postoperative tapentadol IR or oxycodone IR during hospitalization between January 1, 2018 and June 30, 2019, were collected from electronic medical records. The primary outcome was the occurrence of postoperative GI ADEs occurring during hospitalization. This was defined as a composite of nausea, vomiting, or constipation.

RESULTS

The study cohort included 199 patients. Of these, 99 patients received tapentadol IR and 100 patients received oxycodone IR for postoperative pain during hospitalization. The mean age was 66 ± 12 years, and 111 patients (56%) were women. There was no significant difference between groups on the occurrence of GI ADEs (53% in oxycodone group and 51% in tapentadol group, difference 2%, 95% confidence interval [CI], -11% to 16%; P = 0.777). After adjusting for potential confounders, the use of tapentadol IR was not associated with a significant reduction of GI ADEs (odds ratio, 0.62; 95% CI, 0.32-1.20; P = 0.154).

LIMITATIONS

This was a single-center study and should be extrapolated with caution. As this was a retrospective study, the accuracy and availability of data were dependent on documentation in electronic medical records.

CONCLUSIONS

Tapentadol IR is associated with similar GI ADE occurrence compared with oxycodone IR in patients with orthopedic postoperative pain during hospitalization.