Preventive Analgesia: Quo Vadimus?

Comparison of postoperative pain in children after maintenance anaesthesia with propofol or sevoflurane: a systematic review and meta-analysis

BACKGROUND

Propofol and sevoflurane are two of the most commonly used anaesthetics for paediatric surgery. Data from some clinical trials suggest that postoperative pain incidence is lower when propofol is used for maintenance of anaesthesia compared with sevoflurane, although this is not clear.

METHODS

This meta-analysis compared postoperative pain following maintenance of anaesthesia with propofol or sevoflurane in paediatric surgeries. PubMed Medline, Embase, Scopus, Web of Science and Cochrane Library were searched for randomised controlled trials (RCTs) that compared postoperative pain between sevoflurane and propofol anaesthesia in children. After quality assessment, a meta-analysis was carried out using bias-adjusted inverse heterogeneity methods, heterogeneity using I2 and publication bias using Doi plots.

RESULTS

In total, 13 RCTs with 1174 children were included. The overall synthesis suggested nearly two-fold higher odds of overall postoperative pain in the sevoflurane group compared with the propofol group (odds ratio [OR] 1.88, 95% confidence interval [CI] 1.12-3.15, I2=58.2%). Further, children in the sevoflurane group had higher odds of having higher pain scores (OR 3.18, 95% CI 1.83-5.53, I2=20.9%), and a 60% increase in the odds of requiring postoperative rescue analgesia compared with propofol (OR 1.60, 95% CI 0.89-2.88, I2=58.2%).

CONCLUSIONS

Children maintained on inhalational sevoflurane had higher odds of postoperative pain compared with those maintained on propofol. The results also suggest that sevoflurane is associated with higher odds of needing postoperative rescue analgesia compared with propofol.

REGISTRATION

The protocol for this systematic review and meta-analysis was registered on the International Prospective Register of Systematic Reviews (PROSPERO) with registration ID CRD42023445913.

Effects of Ultrasound-Guided Thoracic Paravertebral Nerve Block Combined with Perineural or IV Dexmedetomidine on Acute and Chronic Pain After Thoracoscopic Resection of Lung Lesions: A Double-Blind Randomized Trial

Background

Thoracic paravertebral block (TPVB) analgesia can be prolonged by local anesthetic adjuvants such as dexmedetomidine. This study aimed to evaluate the two administration routes of dexmedetomidine on acute pain and chronic neuropathic pain (NeuP) prevention compared with no dexmedetomidine.

Methods

A total of 216 patients were randomized to receive TPVB using 0.4% ropivacaine alone (R Group), with perineural dexmedetomidine 0.5 μg·kg-1 (RD0.5 Group) or 1.0 μg·kg-1 (RD1.0 Group), or intravenous (IV) dexmedetomidine 0.5 μg·kg-1·h-1 (RDiv Group). The primary outcome was the incidence of chronic NeuP, defined as a Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain score > 12 points at 3-month after surgery.

Results

(1) For the primary outcome, RD0.5 Group and RD1.0 Group demonstrated a decreased incidence of chronic NeuP at 3-month after surgery; (2) Compared with R Group, RDiv Group, RD0.5 Group, and RD1.0 Group can reduce VAS scores at rest and movement and Prince-Henry Pain scores at 12 and 24-h after surgery, the consumption of oral morphine equivalent (OME) and improve QOD-15 at POD1; (3) Compared with RDiv Group, RD0.5 Group and RD1.0 Group can reduce VAS scores at rest and movement and Prince-Henry Pain scores at 12 and 24-h after surgery, the consumption of postoperative OME and improve QOD-15 at POD1; (4) Compared with RD0.5 Group, RD1.0 Group effectively reduced VAS scores at rest at 12 and 24-h after surgery, VAS scores in movement and Prince-Henry Pain scores at 12-h after surgery. However, RD1.0 Group showed an increased incidence of drowsiness.

Conclusion

Perineural or IV dexmedetomidine are similarly effective in reducing acute pain, but only perineural dexmedetomidine reduced chronic NeuP. Moreover, considering postoperative complications such as drowsiness, perineural dexmedetomidine (0.5 μg·kg-1) may be a more appropriate choice.

Clinical Trial Registration

Chinese Clinical Trial Registry (ChiCTR2200058982).

Two doses of subcutaneous methadone for postoperative analgesia in dogs undergoing tibial plateau levelling osteotomies

OBJECTIVES

To evaluate analgesia, sedation and adverse effects of two doses of subcutaneous methadone in dogs undergoing tibial plateau levelling osteotomy.

MATERIALS AND METHODS

Seventeen client-owned dogs undergoing unilateral tibial plateau levelling osteotomy were randomly allocated to receive either 0.25 mg/kg methadone (eight dogs) or 0.5 mg/kg methadone (nine dogs). All dogs were premedicated with methadone and 2 to 6 mcg/kg dexmedetomidine subcutaneously. They were induced and maintained on a standard protocol. All animals received a second dose of methadone subcutaneously 4 hours after premedication and a 4.4 mg/kg dose of carprofen subcutaneously at 8 hours after premedication. During surgery, blood pressure, heart rate and temperature were assessed every 5 minutes. Postoperatively, sedation scores, temperature, heart rate and Glasgow composite modified pain score - short form were assessed for 12 hours postoperatively.

RESULTS

One of 17 (5.9%) dogs had intraoperative hypotension, nine of 17 dogs had intra-operative bradyarrhythmias and 17 of 17 dogs had intra-operative hypothermia. No dogs required intra-operative rescue. Composite modified pain score - short form scores were below the threshold for intervention in 16 of 17 (94.1%) animals. Only one of 17 (5.9%) dogs required rescue analgesia. Median sedation score was 0 by the T8 time point. Adverse events were rare in both groups with only vocalisation and hypothermia reported commonly postoperatively.

CLINICAL SIGNIFICANCE

Two doses of methadone at either 0.25 or 0.5 mg/kg administered via subcutaneous injections pre-operatively and 4 hours later, along with 4.4 mg/kg carprofen subcutaneously 8 hours after the first methadone dose appear to provide sufficient pain control for up to 12 hours in dogs undergoing tibial plateau levelling osteotomy.

Effect of intravenous magnesium on post-operative pain following Latarjet shoulder reconstruction

Background

Single injection ropivacaine interscalene anesthesia (ISA) is frequently used in Latarjet reconstruction to enhance post-operative analgesia. A potential limitation is the occurrence of severe rebound pain on block resolution. We investigated the effect of intravenous magnesium on post-operative pain, particularly at the transition of block resolution to multimodal analgesia.

Methods

Elective patients (n = 40) having Latarjet open shoulder reconstruction were randomised to receive either intravenous magnesium sulphate 50 mg/kg (M) or normal saline (S) before induction. Post-operatively, a standardised analgesic regimen was used, and post-operative pain was recorded using a verbal numerical rating assessment (VNRA) score. Requirement for injected opioid analgesia was recorded.

Results

ISA provided longstanding analgesia in all patients with block duration slightly prolonged in the magnesium group (16.7(1.0) (S), 17.8(1.3) h (M), p = 0.049). Magnesium resulted in less rebound pain following ISA resolution (VNRA 4.0 (0.6) M, 6.2 (0.8) S, p = 0.03) and lower pain intensity at 24 h. Four patients had nausea and two required rescue opioid injection.

Conclusion

Magnesium before Latarjet surgery results in less rebound pain following ropivacaine block and improves post-operative analgesia. Magnesium may be indicated in major upper limb surgery, where significant pain intensity is anticipated.

Level of evidence

Treatment study; Randomised blinded; Level 2.

Comparison of the effects of preoperative celecoxib and gabapentin on pain, functional recovery, and quality of life after total knee arthroplasty: A randomized controlled clinical trial

Background

Acute pain is one of the main complaints of patients after total knee arthroplasty (TKA), which causes delayed mobility, increased morphine consumption, and subsequently increased costs. Therefore, the present study was performed to evaluate the preventive effect of preoperative celecoxib and gabapentin on reducing patient pain as a primary outcome after TKA surgery.

Materials and Methods

This randomized, double-blind controlled clinical trial was performed on 270 patients with osteoarthritis that were candidates for TKA surgery allocated into three groups. In the first group, 900 mg of gabapentin was administered orally on a daily basis for 3 days before surgery. In the second group, 200 mg of oral celecoxib was administered twice daily for 3 days before surgery. In the third group, oral placebo was administered twice daily for 3 days before the surgery. The patients' pain score and knee and its functional score were recoded.

Results

The mean of reduction pain in gabapentin and celecoxib groups was significantly lower than that of the control group at 12, 24, and 48 h after surgery (P < 0.001); however, two groups were not significantly different from each other (P > 0.05). Furthermore, the two medication groups were not significantly different in this regard (P > 0.05). In addition, the knee score in the gabapentin group with the means of 85.40 ± 5.47 and the celecoxib group with the means of 87.03 ± 3.97 were significantly higher than those of the control group with the means of 78.90 ± 4.39 in the 1^st month after the surgery (P < 0.001).

Conclusion

According to the results of the present study, the preventive administration of gabapentin and celecoxib showed a significant and similar effectiveness on reducing patient pain after TKA surgery and on improving the KSS and quality of life scores.

Intraoperative hydromorphone decreases postoperative pain: an instrumental variable analysis

BACKGROUND

Intraoperative administration of short-acting opioids might lead to increased postoperative pain and opioid requirements. There are few data describing the effects of intermediate-duration opioids such as hydromorphone on these outcomes. We have previously shown that a switch from a 2 mg to a 1 mg vial of hydromorphone was associated with decreased intraoperative dose administration. As presentation dose affected intraoperative hydromorphone administration and was unrelated to other policy changes, it could serve as an instrumental variable, assuming significant secular trends were not present during the study period.

METHODS

In this observational cohort study of patients who received intraoperative hydromorphone (n=6750), an instrumental variable analysis was used to evaluate whether intraoperative hydromorphone administration affected postoperative pain scores and opioid administration. Before July 2017, hydromorphone was available as a 2-mg unit dose. From July 1, 2017 to November 20, 2017, hydromorphone was only available in a 1-mg unit dose. A two-stage least squares regression analysis was used to estimate causal effects.

RESULTS

A 0.2-mg increase in intraoperative hydromorphone administration caused a decrease in admission PACU pain scores (mean difference, -0.8; 95% confidence interval, -1.2 to -0.4; P<0.001) and decreased maximum and time-weighted mean pain scores over 2 days postoperatively, without increased opioid administration.

CONCLUSIONS

This study suggests that intraoperative administration of intermediate-duration opioids does not cause the same effects as short-acting opioids with respect to postoperative pain. Instrumental variables can be used to estimate causal effects using observation data when unmeasured confounding is present.

Dexamethasone Does Not Provide Additional Clinical Analgesia Effect to Local Wound Infiltration: A Comprehensive Systematic Review and Meta-Analysis

Objective: Although the use of dexamethasone as an adjunct agent is associated with alleviating pain and prolonging analgesic duration in local wound infiltration (LWI), efficacy and safety of dexamethasone infiltration have not been fully explored. The study sought to quantify the pooled effects of dexamethasone infiltration on postoperative pain, analgesic consumption, and side effects through a review of randomized controlled trials (RCTs). Approach: RCTs comparing dexamethasone + LWI with LWI alone were retrieved from seven electronic databases. Co-primary outcomes were rest pain scores and cumulative morphine equivalent consumption within 24 h postoperatively. The study followed PRISMA, AMSTAR, and the Cochrane Collaboration. Results: Eight trials comprising 609 patients were included in the final analysis. Results indicated that dexamethasone infiltration effects were only statistical but not clinically significant at individual time points of rest pain and patient satisfaction scores. Notably, the effect of dexamethasone infiltration therapy on other pain-related parameters, including cumulative morphine consumption (mean difference, -9.05 mg; 95% CI: -22.47 to 4.37), was not significantly different compared with the control group. Analysis showed no significant differences in safety indicators between the two groups. The overall quality of evidence was high to very low. Innovation: Although statistically significant effects of dexamethasone infiltration were observed for some outcomes of postoperative wound pain, the overall benefits were below the expected minimal clinically important difference. Conclusions: In summary, the current evidence does not support routine clinical use of dexamethasone in LWI. However, further studies should explore the clinical value of preemptive analgesia and safety of a combination of dexamethasone with ropivacaine for LWI.

Effect of perioperative lignocaine infusion on postoperative pain relief for laparoscopic intraperitoneal onlay mesh repair: A randomized controlled study

INTRODUCTION

The focus on enhanced recovery after surgery (ERAS) and opioid-free anesthesia has renewed interest in use of lignocaine. We evaluated postoperative pain relief following intravenous (IV) lignocaine administration in patients undergoing laparoscopic intraperitoneal onlay mesh repair (IPOM).

METHODS

Seventy patients were randomized into two groups. Group L patients were administered IV lignocaine infusion (1.5 mg/kg) at induction of anesthesia followed by infusion (1.5 mg/kg/h), until 1 hour in the post-anesthesia care unit (PACU). Group P patients received equal volumes of normal saline IV infusion. We recorded hemodynamics, perioperative analgesic consumption, postoperative visual analog scores (VAS), incidence of postoperative nausea and vomiting (PONV), bowel function, patient satisfaction and length of hospital stay (LOS).

RESULTS

The hemodynamics in both groups were maintained. Group L had lower VAS scores as compared to Group P (P < .05). Intraoperative fentanyl consumption in Group L was significantly less than Group P (P = .029). Group L patients scored lower on the Likert scale in comparison to the patients of Group P at 0 hour (P = .013). Recovery of bowel function as assessed by time to pass first flatus was significantly shortened by IV lignocaine (P = .001). The perioperative administration of IV lignocaine resulted in decreased postoperative analgesic requirement and greater patient satisfaction scores.

CONCLUSIONS

Perioperative IV lignocaine infusion provided good pain relief, hemodynamic stability and decreased perioperative analgesic consumption. PONV incidence decreased along with an early return of bowel function, reduced LOS and improved patient satisfaction in patients undergoing laparoscopic IPOM surgery.

Comparison of Supraclavicular Regional Nerve Block Versus Infraclavicular Regional Nerve Block in Distal Radial Open Reduction and Internal Fixation: A Retrospective Case Series

Background

The management of pain in patients undergoing open reduction and internal fixation (ORIF) of distal radius fractures (DRFs) remains an area of debate for anesthesiologists due to a variety of block options and no definitive superior technique among these modalities. In this retrospective case series, we compare the efficacy of supraclavicular versus infraclavicular regional nerve blocks for surgical patients undergoing distal radial ORIF operations to determine if one approach was superior.

Methodology

This retrospective case series included patients undergoing ORIF of a DRF at a tertiary academic medical center between April 28, 2016, and August 23, 2021. In total, 54 patients undergoing ORIF of a DRF provided written consent for the nerve block(s) on the day of surgery. Of these 54 patients, 54 (100%) underwent primary procedures. Of the 54 primary ORIF patients, 28 (52%) received the supraclavicular block, while 26 (48%) received the infraclavicular nerve block.

Results

The infraclavicular and supraclavicular groups did not significantly differ regarding age, gender, American Society of Anesthesiologists, weight, or body mass index. The primary (intraoperative opioid use) and secondary (postoperative opioid use, postoperative nausea and vomiting in the post-anesthetic care unit, highest and average pain scores, and time to discharge) outcomes data were included in the study. The infraclavicular and supraclavicular groups did not significantly differ in any of the assessed outcomes except for time to discharge.

Conclusions

The supraclavicular block approach for distal radius ORIF offers an effective and non-inferior alternative to the infraclavicular block approach concerning effective analgesia and safety.

Pain management with popliteal block for fibular graft harvesting in head and neck reconstruction; a randomised double-blind placebo-controlled study

BACKGROUND AND OBJECTIVES

Curative treatment for locally advanced head and neck tumours often includes reconstructive surgery using a microvascular free flap. Effective recuperation is essential but may be impeded by postoperative donor site pain. The aim of this study was to evaluate the effects of a continuous popliteal block on postoperative pain after fibular graft harvesting.

MATERIAL AND METHODS

In this randomized double-blind placebo-controlled study adult patients scheduled for reconstructive head and neck surgery with a microvascular free fibular graft received an indwelling popliteal nerve block catheter and were randomized to receive continuous levobupivacaine/ropivacaine or placebo during the first postoperative week. Primary outcome was postoperative extremity pain assessed using the numerated rating scale (NRS). Secondary outcomes included opioid consumption.

RESULTS

In total 24 patients were included. The median (median, IQR [range]) postoperative extremity NRS scores was lower in the local anaesthetic (LA) group (2, 0-3 [0-10]) compared to the placebo group (2, 1-4 [0-10]), p = 0.008. The LA group also experienced fewer episodes of breakthrough pain, defined as NRS ≥ 4 (17% vs 33% of observations), p = 0.009. Furthermore, median (median, IQR [range]) opioid consumption the first postoperative week was lower in the LA group (109 mg, 74-134 [19-611]) compared to the placebo group (202 mg, 135-241 [78-749]), p = 0.010. No complications attributed to the blocks were observed.

CONCLUSION

Continuous popliteal block significantly reduced postoperative extremity pain and opioid consumption in patients undergoing fibular graft harvesting for head and neck reconstructive surgery.

Impact of Gabapentin on PACU Length of Stay and Perioperative Intravenous Opioid Use for ERAS Hysterectomy Patients

We investigated the impact of preoperative gabapentin on perioperative intravenous opioid requirements and post anesthesia care unit length of stay (PACU LOS) for patients undergoing laparoscopic and vaginal hysterectomies within an Enhanced Recovery After Surgery (ERAS) pathway. A multidisciplinary team retrospectively examined 2,015 patients who underwent laparoscopic or vaginal hysterectomies between October 2016 and January 2020 at a single academic institution. The average PACU LOS was 168 min among patients who did not receive gabapentin vs. 180 min both among patients who received ≤ 300 mg of gabapentin and patients who received > 300 mg of gabapentin. After adjusting for demographics and medical comorbidities, PACU LOS for patients given ≤ 300 mg gabapentin was 6% longer (rate ratio (RR) = 1.06, 95% CI = 1.01-1.11) than for patients who were not given gabapentin, and for patients who received > 300 mg of gabapentin was 7% longer (RR = 1.07, 95%CI = 1.01-1.13) than for those who did not receive gabapentin. Patients who received ≤ 300 mg gabapentin received 9% less perioperative intravenous hydromorphone than patients who did not receive gabapentin (RR = 0.91, 95% CI = 0.86 - 0.97); patients who received > 300 mg of gabapentin received 12% less perioperative intravenous hydromorphone than patients who did not receive gabapentin (RR = 0.88, 95% CI = 0.82 - 0.95). These findings represent an absolute difference of 0.09 mg intravenous hydromorphone. There were no statistically significant differences in total intravenous fentanyl received. Preoperative gabapentin given as part of an ERAS pathway is associated with statistically but not clinically significant increases in PACU LOS and decreases in total perioperative intravenous opioid use.

Preventing Pediatric Chronic Postsurgical Pain: Time for Increased Rigor

Chronic postsurgical pain (CPSP) results from a cascade of events in the peripheral and central nervous systems following surgery. Several clinical predictors, including the prior pain state, premorbid psychological state (e.g., anxiety, catastrophizing), intraoperative surgical load (establishment of peripheral and central sensitization), and acute postoperative pain management, may contribute to the patient’s risk of developing CPSP. However, research on the neurobiological and biobehavioral mechanisms contributing to pediatric CPSP and effective preemptive/treatment strategies are still lacking. Here we evaluate the perisurgical process by identifying key problems and propose potential solutions for the pre-, intra-, and postoperative pain states to both prevent and manage the transition of acute to chronic pain. We propose an eight-step process involving preemptive and preventative analgesia, behavioral interventions, and the use of biomarkers (brain-based, inflammatory, or genetic) to facilitate timely evaluation and treatment of premorbid psychological factors, ongoing surgical pain, and postoperative pain to provide an overall improved outcome. By achieving this, we can begin to establish personalized precision medicine for children and adolescents presenting to surgery and subsequent treatment selection.

How Is Peripheral Injury Signaled to Satellite Glial Cells in Sensory Ganglia?

Injury or inflammation in the peripheral branches of neurons of sensory ganglia causes changes in neuronal properties, including excessive firing, which may underlie chronic pain. The main types of glial cell in these ganglia are satellite glial cells (SGCs), which completely surround neuronal somata. SGCs undergo activation following peripheral lesions, which can enhance neuronal firing. How neuronal injury induces SGC activation has been an open question. Moreover, the mechanisms by which the injury is signaled from the periphery to the ganglia are obscure and may include electrical conduction, axonal and humoral transport, and transmission at the spinal level. We found that peripheral inflammation induced SGC activation and that the messenger between injured neurons and SGCs was nitric oxide (NO), acting by elevating cyclic guanosine monophosphate (cGMP) in SGCs. These results, together with work from other laboratories, indicate that a plausible (but not exclusive) mechanism for neuron-SGCs interactions can be formulated as follows: Firing due to peripheral injury induces NO formation in neuronal somata, which diffuses to SGCs. This stimulates cGMP synthesis in SGCs, leading to their activation and to other changes, which contribute to neuronal hyperexcitability and pain. Other mediators such as proinflammatory cytokines probably also contribute to neuron-SGC communications.

COMPARATIVE ANALGESIC EFFECTS OF SINGLE-DOSE PREOPERATIVE ADMINISTRATION OF PARACETAMOL (ACETAMINOPHEN) 500 mg PLUS CODEINE 30 mg AND IBUPROFEN 400 mg ON PAIN AFTER THIRD MOLAR SURGERY

BACKGROUND

Efficacy and rapid onset of postsurgical oral pain relief are critical to improve clinical outcomes and reduce the risk of excessive dosing with analgesic drugs.

PURPOSE

To compare analgesic effects of preoperative administration of paracetamol 500 mg plus codeine 30 mg in single-tablet and effervescent formulation to ibuprofen 400 mg, and placebo in the management of moderate to severe postoperative pain after mandibular third molar surgery.

MATERIALS AND METHODS

One hundred twenty healthy outpatients aged 15-29 years undergoing surgical removal of 1 bony impacted mandibular third molar were enrolled in this, single-center, prospective, randomized, triple-blind parallel-group, placebo-controlled, clinical trial. Study participants were randomly assigned to three treatment arms. According to the concealed allocation, each patient 30 minutes before surgery received paracetamol 500 mg plus codeine 30 mg (group APAP/COD), ibuprofen 400 mg (group IBU) or placebo (group PLA). Rescue therapy allowed in the postoperative period was paracetamol 500 mg plus codeine 30 mg in groups APAP/COD and PLA and ibuprofen 400 mg in group IBU. Patients recorded on Numerical Rating Scale-11 (NRS-11) the pain intensity, total number of postoperative-supplement medications and time of the first intake, until 12-hours after surgery and over extra 2 days, RESULTS: Over postoperative 3 days, patients in the APAP/COD group (2.33 ± 1.99) displayed significantly (P< .001) less pain intensity than IBU (3.43 ± 2.47) and placebo (3.57 ± 2.62) groups. The first-day postoperative pain was significantly (P < .001) higher in group PLA than in groups APAP/COD and IBU, but not between the latter 2 groups. However, at 2 hours postdose, the IBU group displayed average pain intensity lower than APAP/COD group (P> .05). On the next 2 days, pain intensity was significantly (P< .001) lower in group APAP/COD than in groups IBU and PLA but failed to reach statistical significance between groups IBU and PLA. Although the time to the first using rescue therapy was longer (445.88 ± 159.96 minute) in group IBU, compared to groups APAP/COD (392.67 ± 138.90 minutes) and PLA (323.00 ± 143.95 minutes), the number of supplemented tablets was significantly higher in group IBU (2.89 ± 2.13) than in groups APAP/COD (1.24 ± 1.79) (P= .001) and PLA (1.53 ± 1.67) (P = .008). No adverse events were registered for all groups.

CONCLUSIONS

Within the limits of the present study, over postoperative 3 days, a statistically significant intensity pain reduction and decreased rescue therapy consumption were recorded in the paracetamol-codeine group than to ibuprofen group. Nevertheless, lower pain intensity at 2 hours postdose and longer time using rescue therapy was found in the ibuprofen group without statistical significance. No adverse events occurred over the studied period.

Attitudes and practices of veterinarians in Australia to acute pain management in cats

Objectives

Up-to-date information on the current practices and attitudes of veterinarians in Australia to acute pain management in cats was sought in 2017–2018 in the first nationwide survey in over 20 years.

Methods

An online survey was created, consisting of 54 questions in four sections, with 18 feline-specific questions. Veterinarians throughout Australia were invited to participate in the survey through advertisements in the veterinary press, electronic and regular mail, and through in-clinic visits and promotional materials.

Results

A total of 614 veterinarians completed the survey, with 513 (83.6%) completing the feline-specific section. The demographics of the respondents of this survey were an accurate representation of the registered veterinarians in Australia at the time. Multiple different opioids and non-steroidal anti-inflammatory drugs (NSAIDs) were widely available in practices to manage pain, with analgesic efficacy reported as the primary factor influencing drug selection. Opioids were most commonly used in the preoperative period and NSAIDs were most commonly used postoperatively. Despite the wide availability in clinic (>99%), only 55% of respondents reported regularly using local anaesthetic techniques in cats. Pain assessment of hospitalised patients was primarily performed by veterinarians (91.1%); however, 84.7% of respondents did not routinely use a validated pain scale.

Conclusions and relevance

Veterinary practitioners in Australia are adequately equipped with analgesic medication to treat pain in their patients. In the management of acute pain in cats, they frequently use a multimodal approach and practice a variety of analgesic protocols. Based on the results of this survey, potential areas for improvement in feline pain management include an increase in duration of postoperative analgesia and more routine use of validated pain scales, performed by nurses and veterinarians alike, to assess individual analgesic needs.

Persistent Pain After Cardiac Surgery: Prevention and Management

Persistent postoperative pain (PPP) after cardiac surgery is a significant complication that negatively affects patient quality of life and increases health care system burden. However, there are no standards or guidelines to inform how to mitigate these effects. Therefore, in this review, we will discuss strategies to prevent and manage PPP after cardiac surgery. Adequate perioperative analgesia may prove instrumental in the prevention of PPP. Although opioids have historically been the primary analgesic approach to cardiac surgery, an opioid-sparing strategy may prove advantageous in reducing side effects, avoiding secondary hyperalgesia, and decreasing risk of PPP. Implementing a multimodal analgesic plan using alternative medications and regional anesthetic techniques may offer superior efficacy while reducing adverse effects.

Comparison of local and regional anesthesia modalities in breast surgery: A systematic review and network meta-analysis

STUDY OBJECTIVE

Moderate to severe postoperative pain occurs in up to 60% of women following breast operations. Our aim was to perform a network meta-analysis and systematic review to compare the efficacy and side effects of different analgesic strategies in breast surgery.

DESIGN

Systematic review and network meta-analysis.

SETTING

Operating room, postoperative recovery room and ward.

PATIENTS

Patients scheduled for breast surgery under general anesthesia.

INTERVENTIONS

Following an extensive search of electronic databases, those who received any of the following interventions, control, local anesthetic (LA) infiltration, erector spinae plane (ESP) block, pectoralis nerve (PECS) block, paravertebral block (PVB) or serratus plane block (SPB), were included. Exclusion criteria were met if the regional anesthesia modality was not ultrasound-guided. Network plots were constructed and network league tables were produced.

MEASUREMENTS

Co-primary outcomes were the pain at rest at 0-2 h and 8-12 h. Secondary outcomes were those related to analgesia, side effects and functional status.

MAIN RESULTS

In all, 66 trials met our inclusion criteria. No differences were demonstrated between control and LA infiltration in regard to the co-primary outcomes, pain at rest at 0-2 and 8-12 h. The quality of evidence was moderate in view of the serious imprecision. With respect to pain at rest at 8-12 h, ESP block, PECS block and PVB were found to be superior to control or LA infiltration. No differences were revealed between control and LA infiltration for outcomes related to analgesia and side effects, and few differences were shown between the various regional anesthesia techniques.

CONCLUSIONS

In breast surgery, regional anesthesia modalities were preferable from an analgesic perspective to control or LA infiltration, with a clinically significant decrease in pain score and cumulative opioid consumption, and limited differences were present between regional anesthetic techniques themselves.

Effects of ibuprofen administration timing on oral surgery pain: A randomized clinical trial

OBJECTIVE

This study aimed to compare the analgesic effect of ibuprofen 400 mg given 30 min before or immediately after third molars surgery under local anaesthesia.

MATERIALS AND METHODS

The single-centre, randomized, split-mouth, triple-blind, clinical trial involved 38 outpatients, for a total of 76 bilateral symmetrical fully bone impacted mandibular third molars. Each patient was undergone to separate surgical sessions for the right and left side, and ibuprofen was randomly administered 30 min before or immediately after the intervention. Study participants recorded pain intensity using Numerical Rating Scale-11, the timing of rescue therapy intake and overall tablets consumption over 3 days.

RESULTS

The overall pain intensity score was lower in the group receiving ibuprofen immediately after (3.13 ± 2.46) than before (3.58 ± 2.40) surgery, with statistically significant differences only on the second and third days. The mean time to the first using rescue therapy was longer in the postoperative (598.33 ± 422.62 min) than in the preoperative (406.25 ± 149.79 min) analgesic treatment group (p = .123). The number of supplemented ibuprofen tablets did not differ (p = .530) between both groups.

CONCLUSIONS

Within the limits of the present study, ibuprofen administration immediately after surgery seemed to be more effective than preoperative administration.

Perioperative use of physostigmine to reduce opioid consumption and peri-incisional hyperalgesia: a randomised controlled trial

BACKGROUND

Several studies have shown that cholinergic mechanisms play a pivotal role in the anti-nociceptive system by acting synergistically with morphine and reducing postoperative opioid consumption. In addition, the anti-cholinesterase drug physostigmine that increases synaptic acetylcholine concentrations has anti-inflammatory effects.

METHODS

In this randomised placebo-controlled trial including 110 patients undergoing nephrectomy, we evaluated the effects of intraoperative physostigmine 0.5 mg h^-1 i.v. for 24 h on opioid consumption, hyperalgesia, pain scores, and satisfaction with pain control.

RESULTS

Physostigmine infusion did not affect opioid consumption compared with placebo. However, the mechanical pain threshold was significantly higher (2.3 [sd 0.3]) vs 2.2 [0.4]; P=0.0491), and the distance from the suture line of hyperalgesia (5.9 [3.3] vs 8.5 [4.6]; P=0.006), wind-up ratios (2.2 [1.5] vs 3.1 [1.5]; P=0.0389), and minimum and maximum postoperative pain scores at 24 h (minimum 1.8 [1.0] vs 2.4 [1.2]; P=0.0451; and maximum 3.2 [1.4] vs 4.2 [1.4]; P=0.0081) and 48 h (minimum 0.9 [1.0] vs 1.6 [1.1]; P=0.0101; and maximum 2.0 [1.5] vs 3.2 [1.6]; P=0.0029) were lower in the study group. Pain Disability Index was lower and satisfaction with pain control was higher after 3 months in the physostigmine group.

CONCLUSIONS

In contrast to previous trials, physostigmine did not reduce opioid consumption. As pain thresholds were higher and hyperalgesia and wind-up lower in the physostigmine group, we conclude that physostigmine has anti-hyperalgesic effects and attenuates sensitisation processes. Intraoperative physostigmine may be a useful and safe addition to conventional postoperative pain control.

CLINICAL TRIAL REGISTRATION

EudraCT number 2012-000130-19.

The effectiveness of preemptive analgesia for relieving postoperative pain after video-assisted thoracoscopic surgery (VATS): a prospective, non-randomized controlled trial

Background

The effectiveness of preemptive analgesia (PA) for relieving postoperative pain and reducing the side effects of analgesics following video-assisted thoracoscopic surgery (VATS) has not yet been determined. This study intends to test the clinical application value of PA in the perioperative period of VATS.

Methods

From January 2018 to August 2018, we divided patients who underwent VATS in our hospital into a trial group (PA group) and a control group (traditional analgesia group, TA group). The PA group received a PA program, and the TA group was administered a conventional postoperative analgesia scheme. We compared the two groups according to the intensity of postoperative pain using the numeric rating scale (NRS), the incidence rate of analgesic drug-related adverse reactions, and the severity of stress-induced inflammation.

Results

One hundred five cases from the PA group, and 80 cases from the TA group were included in the analysis. There were no significant differences between the two groups in baseline characteristics (P>0.05). The PA group had a lower incidence rate of side effects from the analgesics compared to the TA group, and there was a statistical difference at 48 and 72 hours after surgery (P<0.05). The PA group had a slightly lower score than the TA group for postoperative resting pain. However, this difference was not statistically significant (P>0.05). The motion pain NRS score of the PA group was lower than the TA group, and although there were no significant differences at 4, 24, and 48 hours (P>0.05), there was a statistically significant difference at 72 hours (P<0.05). In the subset of patients with motion pain NRS ≥3 points, the PA group was marginally higher than the TA group at 4 hours (P>0.05) but was lower than the TA group at 24, 48, and 72 hours, with a statistically significant difference at 24 and 72 hours (P<0.05). There were no statistically significant differences in perioperative stress indexes between the two groups (P>0.05).

Conclusions

PA can relieve postoperative pain following VATS and reduce the incidence rate of analgesic drug-related adverse effects.

Infraclavicular nerve block reduces postoperative pain after distal radial fracture fixation: a randomized controlled trial

Background

It is unclear whether regional anesthesia with infraclavicular nerve block or general anesthesia provides better postoperative analgesia after distal radial fracture fixation, especially when combined with regular postoperative analgesic medications. The aim of this study was to compare the postoperative analgesic effects of regional versus general anesthesia.

Methods

In this prospective, observer blinded, randomized controlled trial, 52 patients undergoing distal radial fracture fixation received either general anesthesia (n = 26) or regional anesthesia (infraclavicular nerve block, n = 26). Numerical rating scale pain scores, analgesic consumption, patient satisfaction, adverse effects, upper limb functional scores (Patient-Rated Wrist Evaluation, QuickDASH), health related quality of life (SF12v2), and psychological status were evaluated after surgery.

Result

Regional anesthesia was associated with significantly lower pain scores both at rest and with movement on arrival to the post-anesthetic care unit; and at 1, 2, 24 and 48 h after surgery (p ≤ 0.001 at rest and with movement). Morphine consumption in the post-anesthetic care unit was significantly lower in the regional anesthesia group (p<0.001). There were no differences in oral analgesic consumption. Regional anesthesia was associated with lower incidences of nausea (p = 0.004), and vomiting (p = 0.050). Patient satisfaction was higher in the regional anesthesia group (p = 0.003). There were no long-term differences in pain scores and other patient outcomes.

Conclusion

Regional anesthesia with ultrasound guided infraclavicular nerve block was associated with better acute pain relief after distal radial fracture fixation, and may be preferred over general anesthesia.

Trial registration

Before subject enrollment, the study was registered at ClinicalTrials.gov (NCT03048214) on 9th February 2017.

From Patient-Controlled Analgesia to Artificial Intelligence-Assisted Patient-Controlled Analgesia: Practices and Perspectives

Pain relief is a major concern for patients who have undergone surgery, and it is an eternal pursuit for anesthesiologists. However, postoperative pain management is far from satisfactory, though the past decades have witnessed great progress in the development of novel analgesics and analgesic techniques. A Cochrane systematic review showed that patient-controlled analgesia (PCA) achieved better pain relief and greater patient satisfaction than traditional “on-demand” parenteral analgesia, suggesting that it might be the manner of analgesia implementation that matters for effective postoperative pain management. A wireless intelligent PCA (Wi-PCA) system that incorporated remote monitoring, an intelligent alarm, intelligent analysis and assessment of the PCA equipment, as well as automatically recording and reserving key information functions under a wireless environment was introduced in our department in 2018. The practice showed that the Wi-PCA system significantly reduced the incidence of moderate to severe postoperative pain and relevant adverse effects, shortened hospital stays, and improved patient satisfaction with postoperative pain relief. Nevertheless, for both traditional and Wi-PCA, analgesics are only administered when pain occurs, leaving behind a realm of possibilities for better postoperative pain management. With the rapid development of machinery and deep learning algorithms, artificial intelligence (AI) is changing the mode of clinical decision making. Integrating the big data collected by state-of-the-art monitoring sensors, the Internet of Things and AI algorithms, an AI-assisted PCA (Ai-PCA) may be a promising future direction for postoperative pain management.

Analgesia in pet rabbits: a survey study on how pain is assessed and ameliorated by veterinary surgeons

BACKGROUND

In the last 20 years, two studies on the veterinary use of perioperative analgesia in small mammals reported a limited use of analgesics in rabbits but suggested an increasing use over the years. The aim of this study was to better understand how pain is treated and ameliorated in rabbits while under veterinary care.

METHODS

An online survey of 60 questions was developed and advertised at national and international veterinary conferences, in veterinary publications and on social media.

RESULTS

In total 94.3 per cent of the respondents routinely administered nonsteroidal anti-inflammatory drugs (NSAIDs) to rabbits undergoing surgical procedures such as neutering, 71.4 per cent administered an opioid and 70.3 per cent routinely administered multimodal analgesia, although dosages do not always match current consensus opinion. Buprenorphine and meloxicam were the most common analgesic drugs prescribed by the respondents. The dosage of meloxicam administered both parenterally and orally varied widely.

CONCLUSION

Rabbit analgesia has improved over recent years similarly to the trend seen in other companion animals. However, overall it seems that pain assessment is still limited in rabbits. The lack of multimodal composite pain scales specific for rabbits makes this task even more challenging.

The influence of preoperative epidural labor analgesia on postoperative pain in parturients undergoing emergency cesarean section : A retrospective analysis

BACKGROUND

Intense noxious input from the periphery may result in central sensitization and hyperexcitability, thus accentuating subsequent postoperative pain. Parturients who undergo emergency cesarean section (C-sec) after experiencing labor pain often develop labor pain-induced sensitization.

OBJECTIVE

This retrospective study evaluated whether parturients without epidural labor analgesia (ELA) who underwent emergency C‑sec, experienced more severe postoperative pain and required more rescue analgesics during the postoperative period.

METHODS

The institution's medical database was searched for parturients who underwent emergency C‑sec under spinal anesthesia for any reason between January 2013 and December 2016. Those who underwent elective C‑sec under spinal anesthesia were included as the reference arm. Parturients were divided into three groups: ELA, no-ELA and elective. Characteristics of patients and perioperative outcomes were evaluated. As primary outcomes, numerical rating scale (NRS) for postoperative pain (0-10) was recorded up to 96 h postoperatively, and use of rescue analgesics was evaluated at 6, 24, and 48 h postoperatively.

RESULTS

In the ELA, no-ELA, and elective groups, 61, 73, and 88 parturients, respectively, were ultimately enrolled. The NRS for pain were similar among the three groups, except at 6 h postoperatively. Parturients in the no-ELA group demonstrated significantly higher NRS at 6 h postoperatively than those in the ELA group (P = 0.01).More patients in the no-ELA group required rescue analgesics than in the ELA (P = 0.001) and elective groups (P < 0.001) at 6-24 h postoperatively. Moreover, the proportion of patients requiring rescue analgesics ≥2 times was also significantly higher in the no-ELA group (vs. the ELA group, P = 0.004; vs. the elective group, P < 0.001).

CONCLUSION

Parturients undergoing emergency C‑sec without ELA management during labor experienced greater postoperative pain and a greater use of rescue analgesics during the postoperative period. The findings suggest that administration of ELA before emergency C‑sec may act as pre-emptive analgesia against postoperative pain.

Unexplained pain after scheduled limb surgery

Orthopedic surgery can lead to pain that is poorly if at all explicable, both in the immediate postoperative period and at longer term, impairing the surgical result and necessitating a multidisciplinary approach of multimodal analgesia throughout the patient's care pathway. Preoperatively, patients at high risk of postoperative pain need to be identified and referred to a pain specialist to optimize pain management. Surgical and anesthesiological measures then need to be taken intraoperatively to limit the risk of pain. Finally, and most importantly, when pain does occur postoperatively, the surgeon needs to be able to treat any obvious cause and then rapidly to call in a pain specialist to identify the underlying causes and treat them effectively.

Postoperative Pain and Analgesic Requirements in the First Year after Intraoperative Methadone for Complex Spine and Cardiac Surgery

BACKGROUND

Methadone is a long-acting opioid that has been reported to reduce postoperative pain scores and analgesic requirements and may attenuate development of chronic postsurgical pain. The aim of this secondary analysis of two previous trials was to follow up with patients who had received a single intraoperative dose of either methadone or traditional opioids for complex spine or cardiac surgical procedures.

METHODS

Preplanned analyses of long-term outcomes were conducted for spinal surgery patients randomized to receive 0.2 mg/kg methadone at the start of surgery or 2 mg hydromorphone at surgical closure, and for cardiac surgery patients randomized to receive 0.3 mg/kg methadone or 12 μg/kg fentanyl intraoperatively. A pain questionnaire assessing the weekly frequency (the primary outcome) and intensity of pain was mailed to subjects 1, 3, 6, and 12 months after surgery. Ordinal data were compared with the Mann-Whitney U test, and nominal data were compared using the chi-square test or Fisher exact probability test. The criterion for rejection of the null hypothesis was P < 0.01.

RESULTS

Three months after surgery, patients randomized to receive methadone for spine procedures reported the weekly frequency of chronic pain was less (median score 0 on a 0 to 4 scale [less than once a week] vs. 3 [daily] in the hydromorphone group, P = 0.004). Patients randomized to receive methadone for cardiac surgery reported the frequency of postsurgical pain was less at 1 month (median score 0) than it was in patients randomized to receive fentanyl (median score 2 [twice per week], P = 0.004).

CONCLUSIONS

Analgesic benefits of a single dose of intraoperative methadone were observed during the first 3 months after spinal surgery (but not at 6 and 12 months), and during the first month after cardiac surgery, when the intensity and frequency of pain were the greatest.

AAAPT Diagnostic Criteria for Acute Abdominal and Peritoneal Pain After Surgery

Abdominal and peritoneal pain after surgery is common and burdensome, yet the lack of standardized diagnostic criteria for this type of acute pain impedes basic, translational, and clinical investigations. The collaborative effort among the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks, American Pain Society, and American Academy of Pain Medicine Pain Taxonomy (AAAPT) provides a systematic framework to classify acute painful conditions. Using this framework, a multidisciplinary working group reviewed the literature and developed core diagnostic criteria for acute abdominal and peritoneal pain after surgery. In this report, we apply the proposed AAAPT framework to 4 prototypical surgical procedures resulting in abdominal and peritoneal pain as examples: cesarean delivery, cholecystectomy, colorectal surgical procedures, and pancreas resection. These diagnostic criteria address the 3 most common surgical procedures performed in the United States, capture diverse surgical approaches, and may also be applied to other surgical procedures resulting in abdominal and peritoneal pain. Additional investigation regarding the validity and reliability of this framework will facilitate its adoption in research that advances our comprehension of mechanisms, deliver better treatments, and help prevent the transition of acute to chronic pain after surgery in the abdominal and peritoneal region. PERSPECTIVE: Using AAAPT, we present key diagnostic criteria for acute abdominal and peritoneal pain after surgery. We provide a systematic classification using 5 dimensions for abdominal and peritoneal pain that occurs after surgery, in addition to 4 specific surgical procedures: cesarean delivery, cholecystectomy, colorectal surgical procedures, and pancreas resection.

The Effect Of The Use Of Pre-Emptive Oral Pregabalin On The Postoperative Spinal Analgesia In Patients Presented For Orthopedic Surgeries: Randomized Controlled Trial

Background

Preoperative oral pregabalin could improve postoperative analgesia and prevent chronic pain development. The aim of this study is to evaluate the effect of oral pregabalin on the duration and quality of postoperative analgesia in spinal anesthesia.

Methods

Sixty adult patients presented for internal fixation of femoral fracture under spinal anesthesia were included in the study. They were randomly distributed to a placebo group and a pregabalin group receiving 150 mg pregabalin capsules 1 hr before surgery. The onset, duration, and regression of sensory and motor block were recorded. Rescue analgesia consumption, postoperative pain score, and quality of sleep were also assessed.

Results

Oral pregabalin significantly prolonged the time to two-segment regression of sensory block, reaching 86.67±17.88 mins, the time required to regression of spinal block to L2, reaching 155.33± 34.71 mins, and the duration of motor block, reaching 138 ± 23.5 mins, with no effect on the onset of sensory or motor block (P = 0.60 and 0.62). It significantly decreased the VAS score 4 hrs, 6 hrs, and 12 hrs postoperatively, prolonged the duration of postoperative analgesia, reaching 392.00±47.23 mins, and decreased morphine consumption to 7.67±3.65 mg. It also improved the quality of sleep in the first night after surgery.

Conclusion

Preemptive oral pregabalin prolonged the time to the first request for postoperative analgesics and improved sleep in the first night after surgery.

Local Wound Infiltration with Ropivacaine for Postoperative Pain Control in Caesarean Section

Background

The rate of the caesarean section has been on a progressive rise ever since its association with improved fetal prognosis was established. This study was conducted to assess the effect of local wound infiltration with ropivacaine on the postoperative analgesia requirement and pain scores in caesarean section patients.

Methods

This was a prospective single-blinded randomized control trial conducted at the Department of Obstetrics and Gynecology, KRL Hospital, Islamabad, Pakistan over a duration of six months from January 2018 to June 2018. All the women aged 19 to 40 years, who underwent elective caesarean sections under spinal anesthesia, with American Society of Anesthesiologists (ASA) score II, were included in the study and randomized into two groups. The primary outcome studied was the efficacy of ropivacaine in controlling postoperative wound pain compared to no local analgesic. Pain severity was assessed using the visual analog scale (VAS) which was explained to the patient beforehand and which comprised a range of score from zero (no pain) to 10 (worst pain imaginable). Initially, paracetamol 1 g intravenous (IV) was given every six hours, over 24 hours. If pain did not settle on this, ketoprofen 3 mg/kg IV was given every eight hours, and in case of further analgesic demand by the patient, nalbuphine 10 mg was given IV, if necessary. The data was collected on a specific questionnaire and analyzed on the Statistical Package for Social Sciences (SPSS Inc., Chicago, IL) version 23.0. A p-value of less than 0.05 was considered significant.

Results

A total of 100 patients were randomized into two groups. Pain scores were significantly reduced in the ropivacaine group at four, six, and 12 hours after surgery. The percentage of patients who requested the multiple doses of IV paracetamol, ketoprofen, and nalbuphine, was significantly lowered in the ropivacaine group as compared to the placebo group (p<0.001).

Conclusions

Local infiltration with ropivacaine during caesarean section significantly reduces the postoperative analgesic requirement and visual analog scores, reducing the incidence of side effects.

Chronic postsurgical pain: From risk factor identification to multidisciplinary management at the Toronto General Hospital Transitional Pain Service

Background: Chronic postsurgical pain is a highly prevalent public health problem associated with substantial emotional, social, and economic costs. Aims: (1) To review the major risk factors for chronic postsurgical pain (CPSP); (2) to describe the implementation of the Transitional Pain Service (TPS) at the Toronto General Hospital, a multiprofessional, multimodal preventive approach to CPSP involving intensive, perioperative psychological, physical, and pharmacological management aimed at preventing and treating the factors that increase the risk of CPSP and related disability; and (3) to present recent empirical evidence for the efficacy of the TPS. Methods: The Toronto General Hospital TPS was specifically developed to target patients at high risk of developing CPSP. The major known risk factors for CPSP are perioperative pain, opioid use, and negative affect, including depression, anxiety, pain catastrophizing, and posttraumatic stress disorder-like symptoms. At-risk patients are identified early and provided comprehensive care by a multidisciplinary team consisting of pain physicians, advanced practice nurses, psychologists, and physical therapists. Results: Preliminary results from two nonrandomized, clinical practice-based trials indicate that TPS treatment is associated with improvements in pain, pain interference, pain catastrophizing, symptoms of anxiety and depression, and opioid use. Almost half of opioid-naïve patients and one in four opioid-experienced patients were opioid free by the 6-month point. Conclusions: These promising results suggest that the TPS benefits patients at risk of CPSP. A multicenter randomized controlled trial of the TPS in several Ontario hospitals is currently underway.

Role of Perioperative Pregabalin in the Management of Acute and Chronic Post-Thoracotomy Pain

BACKGROUND:

Post-thoracotomy pain syndrome (PTPS) can be challenging to treat.

AIM:

This study aimed to evaluate the efficacy of perioperative pregabalin in the prevention of acute and chronic post-thoracotomy pain.

METHODS:

Sixty patients scheduled for thoracotomy for oncologic surgeries were randomly allocated to one of two groups; Pregabalin and Control. In the Pregabalin group, pregabalin 150 mg was administered one hour before thoracotomy and 12 hours later, then every 12 hours for five days. Pain intensity was assessed using the Visual Analogue Scale (VAS) at rest (VAS-R) and dynamic (VAS-D) in the ICU and during the next four days. Morphine consumption and the frequency of side effects were recorded. Assessment of PTPS was done using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale at 1, 2, and 3 months.

RESULTS:

The VAS-R and VAS-D scores and the total morphine consumption were significantly lower in Pregabalin group during days 0 through 4. Neuropathic pain, allodynia, and hyperalgesia were significantly lower in Pregabalin group after 1, 2, and 3 months.

CONCLUSION:

Pregabalin is effective in the reduction of chronic neuropathic pain at 1, 2, and 3 months after thoracotomy and it also reduces pain and opioid consumption during the acute postoperative period with few adverse effects.

Toward a phenomic analysis of chronic postsurgical pain following cardiac surgery

Background: Despite the same surgical approach, up to 40% of patients develop chronic postsurgical pain (CPSP) following cardiac surgery, whereas the rest are chronic pain free. This variability suggests that CPSP is controlled partially through genetics, but the genes for CPSP are largely unknown.

Aims: The aim of this study was to identify potential CPSP phenotypes by comparing patients who developed CPSP following cardiac surgery vs. those who did not.

Methods: A research ethics board–approved, cross-sectional study of post–cardiac surgery pain was conducted at Toronto General Hospital from 2011 to 2015. Patients were recruited to complete a short survey of chronic pain scores and the Short-Form McGill Pain Questionnaire–2. A subset of patients completed a longer survey of eight validated pain phenotyping questionnaires and/or four psychophysical assessments. All surveys and psychophysical testing were conducted after surgery. Patients were stratified by presence of chronic pain and groups were compared using descriptive statistics.

Results: Six hundred forty-three patients completed the short form survey. The mean postsurgery assessment time was 41.5 (SD = ±25.1) months. Over a quarter (27.8%) reported CPSP at the chest as a consequence of their surgery. Of patients reporting CPSP, 46.6% reported mild pain (0–3), 35.8% reported moderate pain (4–7), and 17.6% reported severe pain (7–10) in accordance with the numerical rating scale. Patients with moderate and/or severe CPSP were younger, had a greater body mass index, and had higher anxiety sensitivity, pain catastrophizing, and somatization scores.

Conclusions: Chronic pain levels after cardiac surgery are associated with anxiety, catastrophizing, and sensory abnormalities in body parts outside the field innervated by injured nerves, indicating the presence of widespread central sensitization to incoming sensory inputs from intact nerves.

A prospective comparison of wide-awake local anesthesia and general anesthesia for forefoot surgery

BACKGROUND

A recent case series suggested that surgery with wide-awake local anesthesia is tolerated well by most foot and ankle patients. However, patients were assessed retrospectively and there was no comparison group to show the relative efficacy of this approach. The present study was conducted to address these concerns.

METHODS

Perioperative pain and anxiety were assessed in 40 patients receiving forefoot surgery using either wide-awake local anesthesia or general anesthesia. Ratings were collected on the day of surgery using 11-point (0-10) numerical rating scales.

RESULTS

Patients in the two anesthesia groups reported no differences in preoperative pain (p=0.500) or anxiety (p=0.820). Patients who received wide-awake local anesthesia reported lower levels of postoperative pain (p<0.001) and anxiety (p<0.001) than patients who received general anesthesia. They also reported little pain (M=0.17, SD=0.32) or anxiety (M=1.33, SD=1.74) during the operation.

CONCLUSIONS

Results indicate that surgery with wide-awake local anesthesia is tolerated well by most patients, and that it may have some benefit compared to surgery with general anesthesia.

Optimizing health before elective thoracic surgery: systematic review of modifiable risk factors and opportunities for health services research

Despite progress in many different domains of surgical care, we are still striving toward practices which will consistently lead to the best care for an increasingly complex surgical population. Thoracic surgical patients, as a group, have multiple medical co-morbidities and are at increased risk for developing complications after surgical intervention. Our healthcare systems have been focused on treating complications as they occur in the hopes of minimizing their impact, as well as aiding in recovery. In recent years there has emerged a body of evidence outlining opportunities to optimize patients and likely prevent or decrease the impact of many complications. The purpose of this review article is to summarize four major domains-optimal pain control, nutritional status, functional fitness, and smoking cessation-all of which can have a substantial impact on the thoracic surgical patient's course in the hospital-as well as to describe opportunities for improvement, and areas for future research efforts.

Preventive skin analgesia with lidocaine patch for management of post-thoracotomy pain: Results of a randomized, double blind, placebo controlled study

Background

To evaluate whether pre‐emptive skin analgesia using a lidocaine patch 5% would improve the effects of systemic morphine analgesia for controlling acute post‐thoracotomy pain.

Methods

This was a double‐blind, placebo controlled, prospective study. Patients were randomly assigned to receive lidocaine 5% patch (lidocaine group) or a placebo (placebo group) three days before thoracotomy. Postoperative analgesia was induced in all cases with intravenous morphine analgesia. The intergroup differences were assessed in order to evaluate whether the lidocaine patch 5% would have effects on pain intensity when at rest and after coughing (primary end‐point) on morphine consumption, on the recovery of respiratory function, and on peripheral painful pathways measured with N2 and P2 laser‐evoked potential (secondary end‐points).

Results

A total of 90 patients were randomized, of whom 45 were allocated to the lidocaine group and 45 to the placebo group. Lidocaine compared with the placebo group showed a significant reduction in pain intensity both at rest (P = 0.013) and after coughing (P = 0.015), and in total morphine consumption (P = 0.001); and also showed a better recovery of flow expiratory volume in one second (P = 0.025) and of forced vital capacity (P = 0.037). The placebo group compared with the lidocaine group presented a reduction in amplitude of N2 (P = 0.001) and P2 (P = 0.03), and an increase in the latency of N2 (P = 0.023) and P2 (P = 0.025) laser‐evoked potential.

Conclusions

The preventive skin analgesia with lidocaine patch 5% seems to be a valid adjunct to intravenous morphine analgesia for controlling post‐thoracotomy pain. However, our initial results should be corroborated/confirmed by larger studies.

Tendon Remodeling in Response to Resistance Training, Anabolic Androgenic Steroids and Aging

Exercise training (ET), anabolic androgenic steroids (AAS), and aging are potential factors that affect tendon homeostasis, particularly extracellular matrix (ECM) remodeling. The goal of this review is to aggregate findings regarding the effects of resistance training (RT), AAS, and aging on tendon homeostasis. Data were gathered from our studies regarding the impact of RT, AAS, and aging on the calcaneal tendon (CT) of rats. We demonstrated a series of detrimental effects of AAS and aging on functional and biomechanical parameters, including the volume density of blood vessel cells, adipose tissue cells, tendon calcification, collagen content, the regulation of the major proteins related to the metabolic/development processes of tendons, and ECM remodeling. Conversely, RT seems to mitigate age-related tendon dysfunction. Our results suggest that AAS combined with high-intensity RT exert harmful effects on ECM remodeling, and also instigate molecular and biomechanical adaptations in the CT. Moreover, we provide further information regarding the harmful effects of AAS on tendons at a transcriptional level, and demonstrate the beneficial effects of RT against the age-induced tendon adaptations of rats. Our studies might contribute in terms of clinical approaches in favor of the benefits of ET against tendinopathy conditions, and provide a warning on the harmful effects of the misuse of AAS on tendon development.

Efficacy of preemptive analgesia on acute postoperative pain in children undergoing major orthopedic surgery of the lower extremities

Background

Children undergoing major orthopedic surgery of the lower extremities can experience severe postoperative pain; yet, the ideal postoperative pain management strategy is unknown. Thus, in this patient population, we investigated the effect of intraoperative epidural infusion of local anesthetic on acute postoperative pain and analgesic consumption.

Patients and methods

Patients (N=50, 3-12 years) randomly received either ropivacaine 0.15% (preemptive group) or normal saline (control group) as an initial bolus of 0.2 mL/kg, followed by continuous infusion of 0.15 mL/kg/h throughout surgery. Following surgery, patient-controlled epidural analgesia with ropivacaine 0.1% was provided. The main study outcomes were the revised Face, Legs, Activity, Cry, and Consolability pain scores, epidural ropivacaine consumption, and additional analgesic requirements during the first 48 hours postoperatively.

Results

Forty-seven patients completed the study, 23 in the preemptive group and 24 in the control group, respectively. The revised Face, Legs, Activity, Cry, and Consolability pain scores were significantly lower in the preemptive group only at 30 minutes after postanesthesia care unit arrival and 6 hours after surgery (median difference -1.0, 95% CI -2.0 to -1.0, P=0.001 and median difference -2.0, 95% CI -3.0 to -1.0, P=0.005, respectively). However, they were not significantly different between the groups at 12, 24, and 48 hours postoperatively. Epidural ropivacaine consumption and additional analgesic requirements throughout 48 hours postoperatively were not significantly different between the groups.

Conclusion

Intraoperative epidural infusion of ropivacaine did not demonstrate preemptive analgesic efficacy within 48 hours postoperatively in children undergoing extensive lower limb orthopedic surgery.

Effect of Pre-Emptive Paracetamol Infusion on Postoperative Analgesic Consumption in Children Undergoing Elective Herniorrhaphy

Objective

Studies have suggested that pre-emptive analgesia may decrease postoperative pain and opioid consumption. This study was undertaken to determine whether pre-emptive analgesia reduces postoperative pain and total paracetamol and opioid consumption in children undergoing herniorrhaphy.

Methods

In this retrospective study, medical records were analysed before and after the pre-emptive analgesia regimen was introduced. Demographic data, perioperative drug consumption and discharge time were recorded. In the first group, no pre-emptive analgesia (NA; year, 2011; n=60) was given and in the second group, the pre-emptive analgesia (PA) paracetamol 10-15 mg kg^-1 was given intravenously in the surgical ward at least 1 h before the surgical procedure (year 2013; n=60). Postoperative pain determining supplemental pain medications was scored using a Faces Pain Scale or visual analogue scale. Total paracetamol and opioid consumption during 24 perioperative hours was registered for all patients. The statistical analysis was performed using t test and Chi-square test.

Results

The mean age of children was 69.6±49.9 and 58.7±32.4 months (p=0.157), and the mean body mass index (BMI) was 18.3±8.8 kg m^-2 and 16.4±3.7 kg m^-2 (p=0.125) in the NA and PA groups, respectively. Total paracetamol consumption was 1157.8±908.8 mg vs. 983.0±536.4 mg (p=0.202), and the total opioid consumption was 5.8±4.7 in the NA group and 7.0±4.6 morphine equivalents in the PA group (p=0.160). No differences in the discharge time between the groups were observed (2.1±0.3 vs. 2.0±0.3 days, p=0.13).

Conclusion

PA was proven to be efficient in the terms of postoperative pain control but did not reduce the overall analgesic drug consumption in the children undergoing elective herniorrhaphy. Multimodal pain treatment may decrease the consumption of analgesic drugs.

Prolonged motor block following epidural anaesthesia: A proposed pathway for investigation and management to facilitate rapid MRI scanning to exclude vertebral canal haematoma

Vertebral canal haematoma following epidural anaesthesia is a rare but potentially devastating occurence, which can lead to permanent neurological damage. Early clinical identification and diagnosis using MRI imaging with surgical decompression of the haematoma can lead to full recovery (Kebaish 2004). However surgical patients often have metal clips or staples, which are left inside the body, some of which are not MRI compatible. Currently there is no process to document which surgical clips have been used and their MRI compatibility in an accessible format. This can lead to a delay in performing MRI imaging. We propose a clinical pathway to expedite diagnosis of vertebral canal haematoma to incorporate a system to allow rapid identification of MRI compatibility of surgical clips used during surgery.

Preemptive Analgesia in Total Knee Arthroplasty: Comparing the Effects of Single Dose Combining Celecoxib with Pregabalin and Repetition Dose Combining Celecoxib with Pregabalin: Double-Blind Controlled Clinical Trial

Acute pain is the most common early complication after total knee arthroplasty causing delayed mobilization and increased demands of morphine, leading to higher operative cost. Several studies have assessed the effectiveness, side-effects, and ease of use of various analgesics. Preemptive analgesia with combined celecoxib and pregabalin has been reported to yield positive outcomes. In this randomized, double-blind controlled clinical trial, 30 subjects underwent surgery for total knee arthroplasty using 15-20mg bupivacaine 5% epidural anesthesia. All subjects were divided into three groups. Group 1 was given celecoxib 400mg and pregabalin 150mg 1 hour before the operation, Group 2 was given celecoxib 200mg and pregabalin 75mg twice daily starting from 3 days before the operation, and Group 3 was given a placebo. The outcome was measured with Visual Analog Scale, knee range of motion, and postoperative mobilization. There was a significant difference in postoperative morphine usage between the groups that were administered with preemptive analgesia and the placebo group, but no significant difference was found between Group 1 and Group 2 that were given preemptive analgesia at different doses. ROM and postoperative mobilization were not significantly different among the three groups. Two patients in the first group, one patient in the second group, and one patient in the third group developed nausea. Preemptive analgesia is proven to reduce postoperative usage of morphine independent of the dosage. We recommend the use of combined celecoxib and pregabalin as preemptive analgesia after the total knee arthroplasty procedure. This trial is registered with NCT03523832 (ClinicalTrials.gov).

Pain Management in Pediatric Burn Patients: Review of Recent Literature and Future Directions

Childhood burns are a profoundly traumatic and painful experience. Despite recognition of the prevalence of burn injuries in children and the severity of the associated pain, burn pain remains undertreated. At the same time, more evidence is emerging to suggest that undertreated pain has serious long-term medical and psychiatric consequences, many of which can be ameliorated with improved pain control. Pain in burn patients is, however, notoriously difficult to treat, perhaps because there is a chronic pain aspect underlying the acute pain that accompanies wound care and procedures. This difficulty is compounded by the fact that there are little data to guide decision making in these patients. This article aims to identify the best strategies to guide clinical practice through a review of the past 10 years' development in pediatric burn pain management. However, because clinical investigations remain limited in burned children, we also aim to draw attention to those areas where the data do not identify an optimal approach and further work is needed. Overall, in addition to just the traditional pharmacological approaches to pain, such as acetaminophen, benzodiazepines, and opioids, there is growing evidence to support more widespread use of regional anesthesia and novel technologies such as virtual reality. Starting with an improved understanding of the current state of the literature, we can identify areas of research and important questions whose answers will ultimately improve care and reduce suffering for this unfortunate population of children.

Development of a Multimodal Analgesia Protocol for Perioperative Acute Pain Management for Lower Limb Amputation

Multimodal analgesia may include pharmacological components such as regional anesthesia, opioid and nonopioid systemic analgesics, nonsteroidal anti-inflammatories, and a variety of adjuvant agents. Multimodal analgesia has been reported for a variety of surgical procedures but not yet for lower limb amputation in vasculopathic patients. Perioperative pain management in these patients presents a particular challenge considering the multiple sources and pathways for acute and chronic pain that are involved, such as chronic ischemic limb pain, postoperative residual limb pain, coexisting musculoskeletal pain, phantom limb sensations, and chronic phantom limb pain. These pain mechanisms are explored and a proposed protocol for multimodal analgesia is outlined taking into account the common patient comorbidities found in this patient population.

A comparison between methadone and buprenorphine for perioperative analgesia in dogs undergoing ovariohysterectomy

OBJECTIVE

To investigate whether preoperative methadone provides superior perioperative analgesia compared to buprenorphine in dogs undergoing ovariohysterectomy.

METHODS

Eighty female dogs were recruited to an assessor-blinded, randomised, clinical trial. Dogs received a premedication dose of 0·05 mg/kg acepromazine or 10 μg/kg medetomidine combined with either 0·3 mg/kg methadone or 20 μg/kg buprenorphine intramuscularly. Anaesthesia was induced with propofol and maintained with isoflurane. Pain was assessed using two scoring schemes (a dynamic interactive visual analogue scale and the short form of the Glasgow Composite Pain Scale) before premedication, 30 minutes later and every hour for 8 hours after premedication. If indicated, rescue analgesia was provided with methadone. Meloxicam was administered after the final assessment. The area under the curve for change in pain scores over time and the requirement for rescue analgesia were compared between groups.

RESULTS

Groups premedicated with buprenorphine had significantly higher pain scores than those premedicated with methadone. There was no interaction between opioid and sedative for any outcome measure. Rescue analgesia was required by significantly more dogs premedicated with buprenorphine (45%) than that of methadone (20%).

CLINICAL SIGNIFICANCE

At the doses investigated, methadone produced superior postoperative analgesia compared to buprenorphine in dogs undergoing ovariohysterectomy.