Preventive analgesia

Preprocedural Paracetamol Reduces Pain Scores in Patients Undergoing in-Office Laryngeal Procedures

OBJECTIVE

To investigate the utility of preprocedural paracetamol on reducing pain scores post office-based laryngeal procedures.

STUDY DESIGN

Prospective, controlled before-after comparative study.

SETTING

Controlled prospective before-after study.

METHODS

A retrospective analysis was performed of 100 patients who underwent office-based laryngeal procedures without preprocedural analgesia at our center to establish a control group. Age, sex, procedure type, and amount of substance used were documented as well as postprocedural pain score. Pain scores were recorded every 5 minutes for 30 minutes following office-based laryngeal procedures. A prospective arm of this study was then performed in which every patient undergoing office-based laryngeal procedures at our center between September 2019 and December 2020 was administered 1000 mg of paracetamol prior to their procedure. The postprocedure pain scores of the 2 groups were then compared.

RESULTS

A hundred patients were included in the retrospective arm and 75 patients were included in the prospective arm, receiving 1000 mg of paracetamol a median of 45 (interquartile range: 30-53) minutes prior to their procedure. The 2 groups were matched for age, sex, and type of laryngeal procedure. Both nonanalgesia and analgesia groups demonstrated a similar proportion of patients who experienced any pain (47% and 48%, respectively) postprocedurally. The prospective arm of this study however reported a statistically significant reduction in the magnitude of their pain scores at all points postprocedurally (P = .005).

CONCLUSION

Paracetamol preprocedurally reduces the severity of pain in office-based laryngeal procedures and would be a useful consideration for patients who are likely to experience significant postprocedural pain.

LEVEL OF EVIDENCE

Level 3.

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 Advanced Platelet-Rich Fibrin (A-PRF) on Postoperative Level of Pain and Swelling Following Third Molar Surgery

BACKGROUND

Postoperative pain and swelling following third molar (M3) removal can be debilitating, and there is interest in using advanced platelet-rich fibrin (A-PRF) to reduce their severity.

PURPOSE

This study compared postoperative pain and swelling between A-PRF and gelatin dressing in extraction sockets following mandibular M3 removal.

METHODS, SETTING, SAMPLE

This split-mouth, single-blinded, randomized controlled trial was completed at the Oral Surgery clinic of University of Otago between November 2020 and July 2021. Patients aged between 16 and 40 years with bilaterally impacted mandibular M3 of similar Pederson index difficulty and deemed to be American Society of Anesthesiologists (ASA) I or II comprised the study sample.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

The exposure variable was M3 socket management. One socket received A-PRF and 1 gelatin dressing, while the other received 2 gelatin dressings.

MAIN OUTCOME VARIABLE(S)

The outcome variables were postoperative pain and swelling over 7 days. Pain was measured using the visual analog scale (VAS), and swelling using stereophotogrammetry.

COVARIATES

Demographic characteristics (gender, ethnicity, and age), dental anxiety, smoking status, Pederson index, and intraoperative surgical time were the covariates.

ANALYSES

The two sides were compared using cross-tabulations and the McNemar test for categorical and paired t-tests for continuous variables. Statistical analysis used IBM SPSS Statistics for Windows (version 28).The Alpha level was 0.05.

RESULTS

76 (87.3%) of 87 patients who met the eligibility criteria participated in the study, and 70 patients (65.7% female; age range 16-30 years) were included in the analysis. Mean visual analog scale scores showed no statistically significant difference between the A-PRF and control sides, being 29.6 (95% CI 23.9, 35.3) and 29.5 (95% CI 23.5, 35.5) on day 2, and falling to 12.6 (95% CI 8.7, 16.5) and 14.2 (95% CI 10.0, 18.4) by day 7. Likewise, mean peak facial swelling on day 2 was recorded as 6.3 cm3 (95% CI 4.9, 7.7) and 6.6 cm3 (95% CI 5.5, 7.7), and by day 7 they were 1.1 cm3 (95% CI 0.5, 1.7) and 1.0 cm3 (95% CI 0.3, 0.7) on the A-PRF and control sides, respectively.

CONCLUSIONS

A-PRF placement in M3 sockets did not reduce postoperative pain and swelling over gelatin dressing alone.

Mouse Anesthesia and Analgesia

Providing anesthesia and analgesia for mouse subjects is a common and critical practice in the laboratory setting. This practice is necessary for performing invasive procedures, achieving prolonged immobility for sensitive imaging modalities (magnetic resonance imaging, for instance), and providing intra- and post-procedural pain relief. In addition to facilitating the procedures performed by the investigator, the provision of anesthesia and analgesia is crucial for the preservation of animal welfare and for humane treatment of animals used in research. Furthermore, anesthesia and analgesia are important components of animal use protocols reviewed by Institutional Animal Care and Use Committees, requiring careful consideration and planning for the particular animal model. In this article, we provide technical guidance for the investigator, covering the provision of anesthesia by two routes (injectable and inhalant), guidelines for monitoring anesthesia, current techniques for recognition of pain, considerations for administering preventative analgesia, and considerations for post-operative care. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Injectable anesthesia Basic Protocol 2: Inhalant anesthesia Basic Protocol 3: Assessing pain.

Anesthesia and analgesia for experimental craniotomy in mice and rats: a systematic scoping review comparing the years 2009 and 2019

Experimental craniotomies are a common surgical procedure in neuroscience. Because inadequate analgesia appears to be a problem in animal-based research, we conducted this review and collected information on management of craniotomy-associated pain in laboratory mice and rats. A comprehensive search and screening resulted in the identification of 2235 studies, published in 2009 and 2019, describing craniotomy in mice and/or rats. While key features were extracted from all studies, detailed information was extracted from a random subset of 100 studies/year. Reporting of perioperative analgesia increased from 2009 to 2019. However, the majority of studies from both years did not report pharmacologic pain management. Moreover, reporting of multimodal treatments remained at a low level, and monotherapeutic approaches were more common. Among drug groups, reporting of pre- and postoperative administration of non-steroidal anti-inflammatory drugs, opioids, and local anesthetics in 2019 exceeded that of 2009. In summary, these results suggest that inadequate analgesia and oligoanalgesia are persistent issues associated with experimental intracranial surgery. This underscores the need for intensified training of those working with laboratory rodents subjected to craniotomies.

Systematic review registration

https://osf.io/7d4qe.

Effect of scalp nerve block with ropivacaine on postoperative pain in pediatric patients undergoing craniotomy: A randomized controlled trial

Background

Scalp nerve block (SNB) is widely used for postoperative pain control, intraoperative hemodynamic control, and opioid-sparing in adult craniotomies. However, there are few studies of SNB in pediatric patients undergoing craniotomy. In the present study, we aimed to investigate the effect of SNB on postoperative pain, intraoperative hemodynamic stability, and narcotic consumption in pediatric craniotomy under general anesthesia.

Methods

This trial is a single-center, prospective, randomized, and double-blind study. A total of 50 children aged between 2 and 12 years who are undergoing elective brain tumor surgery will be randomly allocated in a 1:1 ratio to receive either 0.2% ropivacaine for SNB (group SNB, intervention group, n = 25) or the same volume of saline (group Ctrl, control group, n = 25). The primary outcome was to assess the score of postoperative pain intensity at time 1, 4, 8, 12, 24, and 48 h postoperatively using the FLACC score method. Secondary outcomes were to record intraoperative hemodynamic variables (MAP and HR) during skull-pin fixation, skin incision and end of skin closure, intraoperative total consumption of remifentanil and propofol, postoperative opioid consumption, and the incidence of postoperative nausea and vomiting.

Results

Fifty patients were analyzed (n = 25 in SNB group; n = 25 in control group). Compared to the control group, postoperative pain intensity was significantly relieved in the SNB group up to 8 h post-operatively. In addition, SNB provided good intraoperative hemodynamic stability, reduced intraoperative overall propofol and remifentanil consumption rate, and postoperative fentanyl consumption compared to the control group. However, the incidence of postoperative nausea and vomiting was not different between SNB and the control group.

Conclusions

In pediatric craniotomies, SNB with 0.2% ropivacaine provides adequate postoperative pain control and good intraoperative hemodynamic stability during noxious events compared to the control group.

Clinical trial registration

Chinese Clinical Trial Registry [No: ChiCTR2100050594], Prospective registration.

Initiation Timing of Continuous Interscalene Brachial Plexus Blocks in Patients Undergoing Shoulder Arthroplasty: A Retrospective Before-and-After Study

A continuous interscalene brachial plexus block (CIBPB) is usually administered before surgery in awake patients. However, the use of CIBPB before surgery could hinder the identification of nerve injuries after total shoulder arthroplasty (TSA). This study aimed to compare the analgesic effects of preoperatively and postoperatively initiated CIBPBs in patients undergoing TSA. The medical records of patients who underwent TSA between January 2016 and August 2020 were retrospectively reviewed. The following analgesic phases were used: intravenous (IV) patient-controlled analgesia (PCA) phase (IV PCA group, n = 40), preoperative block phase (PreBlock group, n = 44), and postoperative block phase (PostBlock group, n = 33). The postoperative initiation of CIBPB after a neurologic exam provided better analgesia than IV PCA and had no differences with the preoperative initiation of CIBPB, except for the worst pain at the postanesthetic care unit. Opioid consumption was significantly greater in the IV PCA group, but there were no differences between the PreBlock and PostBlock groups on operation day after the transfer to the general ward. The initiation of CIBPB after a patient’s emergence from general anesthesia had comparable analgesic efficacy with preoperative CIBPB but offered the chance of a postoperative neurologic exam.

2022 AAHA Pain Management Guidelines for Dogs and Cats

These updated guidelines present a practical and logical approach to the assessment and management of acute and chronic pain in canine and feline patients. Recognizing pain is fundamental to successful treatment, and diagnostic guides and algorithms are included for assessment of both acute and chronic pain. Particularly for chronic pain, capturing owner evaluation is important, and pain-assessment instruments for pet owners are described. Expert consensus emphasizes proactive, preemptive pain management rather than a reactive, "damage control" approach. The guidelines discuss treatment options centered on preemptive, multimodal analgesic therapies. There is an extensive variety of pharmacologic and nonpharmacologic therapeutic options for the management of acute and chronic pain in cats and dogs. The guidelines include a tiered decision tree that prioritizes the use of the most efficacious therapeutic modalities for the treatment of acute and chronic pain.

Waking Up in Pain: a prospective unselected cohort study of pain in 3702 patients immediately after surgery in the Danish Realm

BACKGROUND

Acute and persistent pain after surgery is well described. However, no large-scale studies on immediate postoperative pain in the operating room (OR) exist, hindering potential areas of research to improve clinical outcomes. Thus, we aimed to describe the occurrence and severity of immediate postoperative pain in a large, unselected cohort.

METHODS

This was a prospective cohort study, encompassing all procedures in 31 public hospitals in the Danish Realm, during a 5-day period including the weekend. Data on procedures and anesthesia were collected and the main outcome was occurrence of moderate or severe pain in the OR. Secondary outcomes included pain, sedation and nausea in the OR or during the first 15 min in the postanesthesia care unit (PACU) including relevant risk factors. Descriptive and logistic regression statistics were used.

RESULTS

A total of 3675 procedures were included for analysis (87% inclusion rate). Moderate or severe pain occurred in 7.4% (95% CI 6.5% to 8.3%) of cases in the OR immediately after awakening, rising to 20.2% in the OR and/or PACU. Large intraprocedure and interprocedure variations occurred (0.0%-37.5%), and in 20% of cases with epidural-general anesthesia patients experienced moderate or severe pain. Independent risk factors were female sex, younger age, preoperative pain, daily opioid use and major surgical procedures.

CONCLUSION

Moderate or severe pain in the immediate postoperative phase occurred in 20% of all cases with procedure and anesthesiological technique variations, suggesting a need for identification of relevant procedure-specific risk factors and development of preventive treatments.

TRIAL REGISTRATION NUMBER

RoPR ID 43191.

Pre-emptive and preventive NSAIDs for postoperative pain in adults undergoing all types of surgery

BACKGROUND

Postoperative pain is a common consequence of surgery and can have many negative perioperative effects. It has been suggested that the administration of analgesia before a painful stimulus may improve pain control. We defined pre-emptive nonsteroidal anti-inflammatories (NSAIDs) as those given before surgery but not continued afterwards and preventive NSAIDs as those given before surgery and continued afterwards. These were compared to a control group given the NSAIDs after surgery instead of before surgery.

OBJECTIVES

To assess the efficacy of preventive and pre-emptive NSAIDs for reducing postoperative pain in adults undergoing all types of surgery.

SEARCH METHODS

We searched the following electronic databases: CENTRAL, MEDLINE, Embase, AMED and CINAHL (up to June 2020). In addition, we searched for unpublished studies in three clinical trial databases, conference proceedings, grey literature databases, and reference lists of retrieved articles. We did not apply any restrictions on language or date of publication.

SELECTION CRITERIA

We included parallel-group randomized controlled trials (RCTs) only. We included adult participants undergoing any type of surgery. We defined pre-emptive NSAIDs as those given before surgery but not continued afterwards and preventive NSAIDs as those given before surgery and continued afterwards. These were compared to a control group given the NSAIDs after surgery instead of before surgery. We included studies that gave the medication by any route but not given on the skin.

DATA COLLECTION AND ANALYSIS

We used the standard methods expected by Cochrane, as well as a novel publication bias test developed by our research group. We used GRADE to assess the certainty of the evidence for each outcome. Outcomes included acute postoperative pain (minimal clinically important difference (MCID): 1.5 on a 0-10 scale), adverse events of NSAIDs, nausea and vomiting, 24-hour morphine consumption (MCID: 10 mg reduction), time to analgesic request (MCID: one hour), pruritus, sedation, patient satisfaction, chronic pain and time to first bowel movement (MCID: 12 hours).

MAIN RESULTS

We included 71 RCTs. Seven studies are awaiting classification. We included 45 studies that evaluated pre-emptive NSAIDs and 26 studies that evaluated preventive NSAIDs. We considered only four studies to be at low risk of bias for most domains. The operations and NSAIDs used varied, although most studies were conducted in abdominal, orthopaedic and dental surgery. Most studies were conducted in secondary care and in low-risk participants. Common exclusions were participants on analgesic medications prior to surgery and those with chronic pain. Pre-emptive NSAIDs compared to post-incision NSAIDs For pre-emptive NSAIDs, there is probably a decrease in early acute postoperative pain (MD -0.69, 95% CI -0.97 to -0.41; studies = 36; participants = 2032; I2 = 96%; moderate-certainty evidence). None of the included studies that reported on acute postoperative pain reported adverse events as an outcome. There may be little or no difference between the groups in short-term (RR 1.00, 95% CI 0.34 to 2.94; studies = 2; participants = 100; I2 = 0%; low-certainty evidence) or long-term nausea and vomiting (RR 0.85, 95% CI 0.52 to 1.38; studies = 5; participants = 228; I2 = 29%; low-certainty evidence). There may be a reduction in late acute postoperative pain (MD -0.22, 95% CI -0.44 to 0.00; studies = 28; participants = 1645; I2 = 97%; low-certainty evidence). There may be a reduction in 24-hour morphine consumption with pre-emptive NSAIDs (MD -5.62 mg, 95% CI -9.00 mg to -2.24 mg; studies = 16; participants = 854; I2 = 99%; low-certainty evidence) and an increase in the time to analgesic request (MD 17.04 minutes, 95% CI 3.77 minutes to 30.31 minutes; studies = 18; participants = 975; I2 = 95%; low-certainty evidence). There may be little or no difference in opioid adverse events such as pruritus (RR 0.40, 95% CI 0.09 to 1.76; studies = 4; participants = 254; I2 = 0%; low-certainty evidence) or sedation (RR 0.51, 95% CI 0.16 to 1.68; studies = 4; participants = 281; I2 = 0%; low-certainty evidence), although the number of included studies for these outcomes was small. No study reported patient satisfaction, chronic pain or time to first bowel movement for pre-emptive NSAIDs. Preventive NSAIDs compared to post-incision NSAIDs For preventive NSAIDs, there may be little or no difference in early acute postoperative pain (MD -0.14, 95% CI -0.39 to 0.12; studies = 18; participants = 1140; I2 = 75%; low-certainty evidence). One study reported adverse events from NSAIDs (reoperation for bleeding) although the events were low which did not allow any meaningful conclusions to be drawn (RR 1.95; 95% CI 0.18 to 20.68). There may be little or no difference in rates of short-term (RR 1.26, 95% CI 0.49 to 3.30; studies = 1; participants = 76; low-certainty evidence) or long-term (RR 0.85, 95% CI 0.52 to 1.38; studies = 5; participants = 456; I2 = 29%; low-certainty evidence) nausea and vomiting. There may be a reduction in late acute postoperative pain (MD -0.33, 95% CI -0.59 to -0.07; studies = 21; participants = 1441; I2 = 81%; low-certainty evidence). There is probably a reduction in 24-hour morphine consumption (MD -1.93 mg, 95% CI -3.55 mg to -0.32 mg; studies = 16; participants = 1323; I2 = 49%; moderate-certainty evidence). It is uncertain if there is any difference in time to analgesic request (MD 8.51 minutes, 95% CI -31.24 minutes to 48.27 minutes; studies = 8; participants = 410; I2 = 98%; very low-certainty evidence). As with pre-emptive NSAIDs, there may be little or no difference in other opioid adverse events such as pruritus (RR 0.56, 95% CI 0.09 to 3.35; studies = 3; participants = 211; I2 = 0%; low-certainty evidence) and sedation (RR 0.84, 95% CI 0.44 to 1.63; studies = 5; participants = 497; I2 = 0%; low-certainty evidence). There is probably little or no difference in patient satisfaction (MD -0.42; 95% CI -1.09 to 0.25; studies = 1; participants = 72; moderate-certainty evidence). No study reported on chronic pain. There is probably little or no difference in time to first bowel movement (MD 0.00; 95% CI -15.99 to 15.99; studies = 1; participants = 76; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

There was some evidence that pre-emptive and preventive NSAIDs reduce both pain and morphine consumption, although this was not universal for all pain and morphine consumption outcomes. Any differences found were not clinically significant, although we cannot exclude this in more painful operations. Moreover, without any evidence of reductions in opioid adverse effects, the clinical significance of these results is questionable although few studies reported these outcomes. Only one study reported clinically significant adverse events from NSAIDs administered before surgery and, therefore, we have very few data to assess the safety of either pre-emptive or preventive NSAIDs. Therefore, future research should aim to adhere to the highest methodology and be adequately powered to assess serious adverse events of NSAIDs and reductions in opioid adverse events.

Synthesis of a PVA drug delivery system for controlled release of a Tramadol-Dexketoprofen combination

The local administration of analgesic combinations by means of degradable polymeric drug delivery systems is an alternative for the management of postoperative pain. We formulated a Tramadol-Dexketoprofen combination (TDC) loaded in poly(vinyl alcohol) (PVA) film. Films were prepared by the solvent casting method using three different molecular weights of PVA and crosslinking those films with citric acid, with the objective of controlling the drug release rate, which was evaluated by UV-vis spectrometry. Non-crosslinked PVA films were also evaluated in the experiments. Differential scanning calorimetry (DSC) analysis of samples corroborated the crosslinking of PVA by the citric acid. Blank and loaded PVA films were tested in vitro for its impact on blood coagulation prothrombin time (PT) and partial thromboplastin time (PTT). The swelling capacity was also evaluated. Crosslinked PVA films of higher-molecular weight showed a prolonged release rate compared with that of the lower-molecular-weight films tested. Non-crosslinked PVA films released 11-14% of TDC. Crosslinked PVA films released 80% of the TDC loaded (p < 0.05). This suggests that crosslinking films can modify the drug release rate. The blank and loaded PVA films induced PT and PTT in the normal range. The results showed that the polymeric films evaluated here have the appropriate properties to allow films to be placed directly on surgical wounds and have the capacity for controlled drug release to promote local analgesia for the control of postoperative pain.

Managing pain associated with dermatologic procedures

Dermatologists are faced with an aging population, accompanied by an increase in the incidence of skin cancer, especially nonmelanoma skin cancer. With this increase in cutaneous malignancy comes an increase in the number of dermatologic procedures being performed. A common concern of dermatologists and dermatology patients is the attenuation and management of pain associated with dermatologic procedures. Fortunately, there are several techniques that may be used in the preoperative, intraoperative, and postoperative periods to manage patient anxiety, minimize injection pain, and safely and effectively treat postoperative pain.

The transversus abdominis plane block may reduce chronic postoperative pain one year after TAPP ingunial hernia repair

Introduction

Chronic postoperative inguinal pain (CPIP) is defined as pain impacting daily activities lasting at least 3 months. With an incidence of 0.5–6.0%, chronic pain affects many patients who underwent inguinal hernia repair (IHR). Early severe postoperative pain has been described as a risk factor for CPIP. Thus, we aim to investigate the impact of the transversus abdominis plane (TAP) block on CPIP.

Methods

From 2013 to 2019 we collected data from individuals who were operated on electively in TAPP technique and who received a preoperative TAP block.

Results

Data from 289 patients were selected. 259 patients were male. The mean age was 59.93 years and the mean BMI was 25.72 kg/m2. 252 patients suffered from a primary inguinal hernia. No mesh fixation was conducted. 21 patients reported pain at rest, 26 pain under physical exertion and 13 patients required treatment of their pain. In 6.25% of cases patients reported CPIP. We compared our findings with data from the German Herniamed Registry (unilateral, primary IH, men, no mesh fixation; n = 8.799), because we assume that the majority of these patients did not receive a TAP block. The rate of pain under physical exertion (9.2% vs. 10.05%) and pain requiring treatment (2.45% vs. 2.95%) one year after surgery slightly differs without a statistical significance.

Conclusions

We assume that the TAP block may reduce CPIP, postoperative pain during physical exertion and pain requiring treatment following IHR in TAPP technique. Additional randomized clinical trials are mandatory to evaluate the hypothesis.

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The TAP block may reduce the rate of chronic postoperative inguinal pain.

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The TAP block may reduce the rate of pain requiring treatment and on exertion one year after IHR.

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The TAP should further implemented into daily hernia surgery routine.

Effect of Low-Dose Dexmedetomidine on the Anesthetic and Recovery Profile of Sevoflurane-Based Anesthesia in Patients Presenting for Supratentorial Neurosurgeries: A Randomized Double-Blind Placebo-Controlled Trial

Background  Dexmedetomidine could be a suitable adjuvant in neuroanesthesia due to its analgesic and anesthetic-sparing properties with the added advantage of facilitating intraoperative neuromonitoring. However, its recovery profile is still debated upon, as in neuroanesthesia, a prompt recovery is essential for postoperative neurologic assessment. We designed this study to evaluate the effect of dexmedetomidine on the anesthetic and recovery profile of patients presenting for supratentorial neurosurgeries. Materials and Methods  Forty adult patients undergoing supratentorial surgeries were recruited in this prospective, randomized, double-blinded study and were divided into two groups: group S and group SD. Both groups received sevoflurane and fentanyl for maintenance, whereas group SD alone received a low dose of dexmedetomidine infusion. Recovery parameters, opioid consumption, Richmond Agitation-Sedation Scale (RASS) and visual analogue scale (VAS) scores, incidence of nausea and vomiting, and intraoperative hemodynamics were analyzed. Results   There were no statistically significant differences between the groups S and SD in case of recovery parameters-time taken (in minutes, presented as median with interquartile range [IQR]) for (1) eye-opening to command: 9.5 (8-18) versus 22.5 (5-47.5) ( p = 0.414); 2) following verbal command: 10.5 (8.25-29.5) versus 25 (10-28.75) ( p = 0.512); (3) extubation: 11 (9.25-22) versus 25 (10-30) ( p = 0.277); and (4) getting oriented to place, time, and date: 23 (20-52.75) versus 27.5 (25-36.5) ( p = 0.121). Fentanyl consumption was significantly less in group SD (451 ± 39.3) versus group S (524.3 ± 144.1) ( p = 0.034). The median RASS score with IQR and the median VAS scores with IQR were comparable between the groups at all time points. Of the 20 patients in group S, 5 had complaints of nausea and vomiting compared with none in the group SD, although it was not statistically significant. The hemodynamic parameters did not show a significant difference between the groups except for a surge in mean arterial pressure at 30 minutes in group S. Conclusion  Low-dose dexmedetomidine as an adjuvant to sevoflurane- and fentanyl-based anesthesia could provide stable hemodynamics and lesser anesthetics and opioid consumption, without adversely affecting the recovery profile in patients undergoing supratentorial neurosurgical procedures.

Postoperative pain pathophysiology and treatment strategies after CRS + HIPEC for peritoneal cancer

Background

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment choice for peritoneal cancer. However, patients commonly suffer from severe postoperative pain. The pathophysiology of postoperative pain is considered to be from both nociceptive and neuropathic origins.

Main body

The recent advances on the etiology of postoperative pain after CRS + HIPEC treatment were described, and the treatment strategy and outcomes were summarized.

Conclusion

Conventional analgesics could provide short-term symptomatic relief. Thoracic epidural analgesia combined with opioids administration could be an effective treatment choice. In addition, a transversus abdominis plane block could also be an alternative option, although further studies should be performed.

Hyperoxia and antioxidants during major non-cardiac surgery and risk of cardiovascular events: Protocol for a 2 × 2 factorial randomised clinical trial

BACKGROUND

Myocardial injury after non-cardiac surgery occurs in a high number of patients, resulting in increased mortality in the post-operative period. The use of high inspiratory oxygen concentrations may cause hyperoxia, which is associated with impairment of coronary blood flow. Furthermore, the surgical stress response increases reactive oxygen species, which is involved in several perioperative complications including myocardial injury and death. Avoidance of hyperoxia and substitution of reactive oxygen species scavengers may be beneficial. Our primary objective is to examine the effect of oxygen and added antioxidants for prevention of myocardial injury assessed by area under the curve for troponin measurements during the first three post-operative days.

METHODS

The VIXIE trial (VitamIn and oXygen Interventions and cardiovascular Events) is an investigator-initiated, blinded, 2 × 2 factorial multicentre clinical trial. We include 600 patients with cardiovascular risk factors undergoing major non-cardiac surgery. Participants are randomised to an inspiratory oxygen fraction of 0.80 or 0.30 during and for 2 hours after surgery and either an intravenous bolus of vitamin C and an infusion of N-acetylcysteine or matching placebo of both. The primary outcome is the area under the curve for high-sensitive cardiac troponin release during the first three post-operative days as a marker of the extent of myocardial injury. Secondary outcomes are mortality, non-fatal myocardial infarction and non-fatal serious adverse events within 30 days.

PERSPECTIVE

The current trial will provide further evidence for clinicians on optimal administration of perioperative oxygen in surgical patients with cardiovascular risks and the clinical effects of two common antioxidants.

Acute Pain in Older Adults: Recommendations for Assessment and Treatment

The management of acute pain in older adults (age 65 or greater) requires special attention due to various physiologic, cognitive, functional, and social issues that may change with aging. Especially in the postoperative setting, there are significant complications that can occur if pain is not treated adequately for elderly patients. In this article, the authors describe these changes in detail and discuss how pain should be assessed appropriately in older patients. In addition, the authors detail the unique risks and benefits of several mainstream analgesic medications as well as interventional treatments for elderly patients. The authors' goal is to provide recommendations for health care providers on appropriately recognizing and treating pain in a safe, effective manner for aging patients.

Sex differences in negative affect and postoperative pain in patients undergoing total knee arthroplasty

Background

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence in the developed world, and affects women to a greater degree than men. In the USA, the growth of knee OA has been paralleled by an increase in rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, postoperative trajectories of pain vary widely, with some patients reporting a complete absence of pain, but with a significant minority reporting worsening pain. Biopsychosocial factors, including anxiety and depression, are known to contribute importantly to the experience of joint pain, with women reporting a higher degree of negative affective symptoms.

Methods

This study investigated sex differences in TKA outcomes in age-matched groups of men and women at two academic medical centers. Pain and physical function were assessed in 100 patients (50 men and 50 women) during the perioperative period (preoperative visit—6 weeks postsurgical). The association of preoperative negative affect (anxiety and depression scores) to postoperative pain and function was evaluated, with specific attention to sex differences in this relationship.

Results

Overall, women reported more baseline pain-related physical dysfunction (although not higher baseline pain scores), as well as higher acute postoperative pain scores during the 2 weeks following TKA than their male counterparts. By 6 weeks postoperatively, sex differences in reported pain were no longer evident. Interestingly, although women reported higher preoperative levels of emotional distress than men, preoperative anxiety and depression scores were better predictors of severe postoperative pain among men than women, throughout the postoperative test period.

Conclusions

This study underlines the importance of considering sex and psychosocial factors, as well as their interaction, in understanding postsurgical pain trajectories.

Pre-emptive and preventive opioids for postoperative pain in adults undergoing all types of surgery

BACKGROUND

Postoperative pain is a common consequence of surgery and can have deleterious effects. It has been suggested that the administration of opioid analgesia before a painful stimulus may improve pain control. This can be done in two ways. We defined 'preventive opioids' as opioids administered before incision and continued postoperatively, and 'pre-emptive opioids' as opioids given before incision but not continued postoperatively. Both pre-emptive and preventive analgesia involve the initiation of an analgesic agent prior to surgical incision with the aim of reducing intraoperative nociception and therefore postoperative pain.

OBJECTIVES

To assess the efficacy of preventive and pre-emptive opioids for reducing postoperative pain in adults undergoing all types of surgery.

SEARCH METHODS

We searched the following electronic databases: CENTRAL, MEDLINE, Embase, AMED, and CINAHL (up to 18 March 2018). In addition, we searched for unpublished studies in three clinical trial databases, conference proceedings, grey literature databases, and reference lists of retrieved articles. We did not apply any restrictions on language or date of publication.

SELECTION CRITERIA

We included parallel-group randomized controlled trials (RCTs) only. We included participants aged over 15 years old undergoing any type of surgery. We defined postincision opioids as the same intervention administered after incision whether single dose (as comparator with pre-emptive analgesia) or continued postoperatively (as comparator with preventive analgesia) (control group). We considered studies that did and did not use a double-dummy placebo (e.g. intervention group received active drug before incision and placebo after incision; control group received placebo before incision and active drug after incision).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcomes were: early acute postoperative pain (measured within six hours and reported on a 0-to-10 scale) and respiratory depression. Our secondary outcomes included: late acute postoperative pain (24 to 48 hours and reported on a 0-to-10 scale), 24-hour morphine consumption, and adverse events (intraoperative bradycardia and hypotension). We used GRADE to assess the quality of the evidence for each outcome.

MAIN RESULTS

We included 20 RCTs, including one unpublished study with 1343 participants. Two studies were awaiting classification as the full text for these studies was not available. One study evaluated pre-emptive opioids, and 19 studies evaluated preventive opioids. We considered only one study to be at low risk of bias for most domains. The surgeries and opioids used varied, although roughly half of the included studies were conducted in abdominal hysterectomy, and around a quarter used morphine as the intervention. All studies were conducted in secondary care.Pre-emptive opioids compared to postincision opioidsFor pre-emptive opioids in dental surgery, there may be a reduction in early acute postoperative pain (mean difference (MD) -1.20, 95% confidence interval (CI) -1.75 to -0.65; 40 participants; 1 study; low-quality evidence). This study did not report on adverse events (respiratory depression, bradycardia, or hypotension). There may be a reduction in late acute postoperative pain (MD -2.10, 95% CI -2.57 to -1.63; 40 participants; 1 study; low-quality evidence). This study did not report 24-hour morphine consumption.Preventive opioids compared to postincision opioidsFor preventive opioids, there was probably no reduction in early acute postoperative pain (MD 0.11, 95% CI -0.32 to 0.53; 706 participants; 10 studies; I² = 61%; moderate-quality evidence). There were no events of respiratory depression in four studies (433 participants). There was no important reduction in late acute postoperative pain (MD -0.06, 95% CI -0.13 to 0.01; 668 participants; 9 studies; I² = 0%; moderate-quality evidence). There may be a small reduction in 24-hour morphine consumption (MD -4.91 mg, 95% CI -9.39 mg to -0.44 mg; 526 participants; 11 studies; I² = 82%; very low-quality evidence). There may be similar rates of bradycardia (risk ratio (RR) 0.33, 95% CI 0.01 to 7.88; 112 participants; 2 studies; I² = 0%; low-quality evidence) and hypotension (RR 1.08, 95% CI 0.25 to 4.73; 88 participants; 2 studies; I² = 0%; low-quality evidence).

AUTHORS' CONCLUSIONS

Due to the low quality of the evidence, we are uncertain whether pre-emptive opioids reduce postoperative pain. Based on the trials conducted thus far, there was no clear evidence that preventive opioids result in reductions in pain scores. It was unclear if there was a reduction in morphine consumption due to very low-quality of evidence. Too few studies reported adverse events to be able to draw any definitive conclusions. Once assessed, the two studies awaiting classification may alter the conclusions of the review.

Acute complications in the post-anaesthesia care unit after infrainguinal surgery for lower limb ischaemia - a prospective observational cohort study

BACKGROUND

Arterial surgery for lower limb ischaemia is a frequently performed procedure in patients with severe cardio-pulmonary comorbidities, making them high-risk patients for acute postoperative complications with a need for prolonged stay in the post-anaesthesia care unit (PACU). However, detailed information on complications during the PACU stay is limited, hindering mechanism-based interventions for early enhanced recovery. Thus, we aimed to systematically describe acute complications and related risk factors in the immediate postoperative phase after infrainguinal arterial surgery.

PATIENTS AND METHODS

Patients transferred to the PACU after infrainguinal arterial surgery due to chronic or acute lower limb ischaemia were consecutively included in a six-month observational cohort study. Pre- and intraoperative data included comorbidities as well as surgical and anaesthetic technique. Data on complications and treatments in the PACU were collected every 15 minutes using a standardised assessment tool. The primary endpoint was occurrence of predefined moderate or severe complications occurring during PACU stay.

RESULTS

In total, 155 patients were included for analysis. Eighty (52 %) patients experienced episodes with oxygen desaturation (< 85 %) and moderate or severe pain occurred in 72 patients (47 %); however, circulatory complications (hypotension, tachycardia) were rare. Preoperative opioid use was a significant risk factor for moderate or severe pain in PACU (59 vs. 38 % chronic vs. opioid naïve patients (P = 0.01).

CONCLUSIONS

Complications in the PACU after infrainguinal arterial surgery relates to saturation and pain, suggesting that future efforts should focus on anaesthesia and analgesic techniques including opioid sparing regimes to enhance early postoperative recovery.

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.

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.

Practice and bias in intraoperative pain management: results of a cross-sectional patient study and a survey of anesthesiologists

Background

Perioperative pain carries a considerable risk of becoming persistent; hence aggressive preventive approaches are advocated. Persistently high prevalence of postoperative pain, however, suggests anesthesiologists underuse these strategies. A prospective cross-sectional study of patients in the postanesthetic care unit (PACU) and a survey of anesthesiologists were thus conducted to evaluate practice and uncover bias in intraoperative pain management.

Methods

Notes of PACU patients were reviewed and information regarding surgical context, comorbidities, and analgesic administration was retrieved. Variables were analyzed for their predictive properties on pain and intraoperative analgesic management. Furthermore, clinical dose–effect estimates for intraoperative morphine were determined. Finally, anesthesiologists completed a questionnaire comprising statements regarding pain relating to surgical context and morphine administration.

Results

Data of 200 patients and 55 anesthesiologists were analyzed. Prevalence of pain in PACU was 28% and was predicted by local anesthetic (LA) and low-dose morphine administration. Additionally, when LA was used, little coanalgesics were employed. These results suggest a restrained approach by anesthesiologists toward intraoperative pain management. It is supported by their reluctance to administer more than 10 mg morphine, despite these individuals regarding this practice as insufficient. The hesitancy toward morphine also transpired in the dose–effect estimates with the average applied dose operating on an ED₆₃ instead of an ED₉₅ level.

Conclusion

This study confirmed a high prevalence of pain in PACU. It also indicated conservative intraoperative analgesic administration by anesthesiologists. The modest morphine usage and overreliance on LA application, which are not supported by published evidence, additionally suggest bias in current intraoperative pain management.

International guidelines for groin hernia management

INTRODUCTION

Worldwide, more than 20 million patients undergo groin hernia repair annually. The many different approaches, treatment indications and a significant array of techniques for groin hernia repair warrant guidelines to standardize care, minimize complications, and improve results. The main goal of these guidelines is to improve patient outcomes, specifically to decrease recurrence rates and reduce chronic pain, the most frequent problems following groin hernia repair. They have been endorsed by all five continental hernia societies, the International Endo Hernia Society and the European Association for Endoscopic Surgery.

METHODS

An expert group of international surgeons (the HerniaSurge Group) and one anesthesiologist pain expert was formed. The group consisted of members from all continents with specific experience in hernia-related research. Care was taken to include surgeons who perform different types of repair and had preferably performed research on groin hernia surgery. During the Group's first meeting, evidence-based medicine (EBM) training occurred and 166 key questions (KQ) were formulated. EBM rules were followed in complete literature searches (including a complete search by The Dutch Cochrane database) to January 1, 2015 and to July 1, 2015 for level 1 publications. The articles were scored by teams of two or three according to Oxford, SIGN and Grade methodologies. During five 2-day meetings, results were discussed with the working group members leading to 136 statements and 88 recommendations. Recommendations were graded as "strong" (recommendations) or "weak" (suggestions) and by consensus in some cases upgraded. In the Results and summary section below, the term "should" refers to a recommendation. The AGREE II instrument was used to validate the guidelines. An external review was performed by three international experts. They recommended the guidelines with high scores. The risk factors for inguinal hernia (IH) include: family history, previous contra-lateral hernia, male gender, age, abnormal collagen metabolism, prostatectomy, and low body mass index. Peri-operative risk factors for recurrence include poor surgical techniques, low surgical volumes, surgical inexperience and local anesthesia. These should be considered when treating IH patients. IH diagnosis can be confirmed by physical examination alone in the vast majority of patients with appropriate signs and symptoms. Rarely, ultrasound is necessary. Less commonly still, a dynamic MRI or CT scan or herniography may be needed. The EHS classification system is suggested to stratify IH patients for tailored treatment, research and audit. Symptomatic groin hernias should be treated surgically. Asymptomatic or minimally symptomatic male IH patients may be managed with "watchful waiting" since their risk of hernia-related emergencies is low. The majority of these individuals will eventually require surgery; therefore, surgical risks and the watchful waiting strategy should be discussed with patients. Surgical treatment should be tailored to the surgeon's expertise, patient- and hernia-related characteristics and local/national resources. Furthermore, patient health-related, life style and social factors should all influence the shared decision-making process leading up to hernia management. Mesh repair is recommended as first choice, either by an open procedure or a laparo-endoscopic repair technique. One standard repair technique for all groin hernias does not exist. It is recommended that surgeons/surgical services provide both anterior and posterior approach options. Lichtenstein and laparo-endoscopic repair are best evaluated. Many other techniques need further evaluation. Provided that resources and expertise are available, laparo-endoscopic techniques have faster recovery times, lower chronic pain risk and are cost effective. There is discussion concerning laparo-endoscopic management of potential bilateral hernias (occult hernia issue). After patient consent, during TAPP, the contra-lateral side should be inspected. This is not suggested during unilateral TEP repair. After appropriate discussions with patients concerning results tissue repair (first choice is the Shouldice technique) can be offered. Day surgery is recommended for the majority of groin hernia repair provided aftercare is organized. Surgeons should be aware of the intrinsic characteristics of the meshes they use. Use of so-called low-weight mesh may have slight short-term benefits like reduced postoperative pain and shorter convalescence, but are not associated with better longer-term outcomes like recurrence and chronic pain. Mesh selection on weight alone is not recommended. The incidence of erosion seems higher with plug versus flat mesh. It is suggested not to use plug repair techniques. The use of other implants to replace the standard flat mesh in the Lichtenstein technique is currently not recommended. In almost all cases, mesh fixation in TEP is unnecessary. In both TEP and TAPP it is recommended to fix mesh in M3 hernias (large medial) to reduce recurrence risk. Antibiotic prophylaxis in average-risk patients in low-risk environments is not recommended in open surgery. In laparo-endoscopic repair it is never recommended. Local anesthesia in open repair has many advantages, and its use is recommended provided the surgeon is experienced in this technique. General anesthesia is suggested over regional in patients aged 65 and older as it might be associated with fewer complications like myocardial infarction, pneumonia and thromboembolism. Perioperative field blocks and/or subfascial/subcutaneous infiltrations are recommended in all cases of open repair. Patients are recommended to resume normal activities without restrictions as soon as they feel comfortable. Provided expertise is available, it is suggested that women with groin hernias undergo laparo-endoscopic repair in order to decrease the risk of chronic pain and avoid missing a femoral hernia. Watchful waiting is suggested in pregnant women as groin swelling most often consists of self-limited round ligament varicosities. Timely mesh repair by a laparo-endoscopic approach is suggested for femoral hernias provided expertise is available. All complications of groin hernia management are discussed in an extensive chapter on the topic. Overall, the incidence of clinically significant chronic pain is in the 10-12% range, decreasing over time. Debilitating chronic pain affecting normal daily activities or work ranges from 0.5 to 6%. Chronic postoperative inguinal pain (CPIP) is defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively and decreasing over time. CPIP risk factors include: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia and open repair. For CPIP the focus should be on nerve recognition in open surgery and, in selected cases, prophylactic pragmatic nerve resection (planned resection is not suggested). It is suggested that CPIP management be performed by multi-disciplinary teams. It is also suggested that CPIP be managed by a combination of pharmacological and interventional measures and, if this is unsuccessful, followed by, in selected cases (triple) neurectomy and (in selected cases) mesh removal. For recurrent hernia after anterior repair, posterior repair is recommended. If recurrence occurs after a posterior repair, an anterior repair is recommended. After a failed anterior and posterior approach, management by a specialist hernia surgeon is recommended. Risk factors for hernia incarceration/strangulation include: female gender, femoral hernia and a history of hospitalization related to groin hernia. It is suggested that treatment of emergencies be tailored according to patient- and hernia-related factors, local expertise and resources. Learning curves vary between different techniques. Probably about 100 supervised laparo-endoscopic repairs are needed to achieve the same results as open mesh surgery like Lichtenstein. It is suggested that case load per surgeon is more important than center volume. It is recommended that minimum requirements be developed to certify individuals as expert hernia surgeon. The same is true for the designation "Hernia Center". From a cost-effectiveness perspective, day-case laparoscopic IH repair with minimal use of disposables is recommended. The development and implementation of national groin hernia registries in every country (or region, in the case of small country populations) is suggested. They should include patient follow-up data and account for local healthcare structures. A dissemination and implementation plan of the guidelines will be developed by global (HerniaSurge), regional (international societies) and local (national chapters) initiatives through internet websites, social media and smartphone apps. An overarching plan to improve access to safe IH surgery in low-resource settings (LRSs) is needed. It is suggested that this plan contains simple guidelines and a sustainability strategy, independent of international aid. It is suggested that in LRSs the focus be on performing high-volume Lichtenstein repair under local anesthesia using low-cost mesh. Three chapters discuss future research, guidelines for general practitioners and guidelines for patients.

CONCLUSIONS

The HerniaSurge Group has developed these extensive and inclusive guidelines for the management of adult groin hernia patients. It is hoped that they will lead to better outcomes for groin hernia patients wherever they live. More knowledge, better training, national audit and specialization in groin hernia management will standardize care for these patients, lead to more effective and efficient healthcare and provide direction for future research.

Assessing and mitigating post-operative castration pain in Bos indicus cattle

Cattle on pastoral land are subject to potentially painful husbandry procedures. In northern Australia, these practices generally occur once a year after the muster and the procedures are usually performed on animals older than 6 months of age. It is seldom that any pain mitigating medications are administered at this time and there is increasing concern that this perceived impost on the animal’s welfare will become more significant at both an economic and cultural level. There is a need to investigate the possibility of using simple, cost-effective, readily available medications, administered using relatively quick and easily taught techniques to increase the chance of industry adoption. This research used castration of 6–8-month-old Bos indicus calves as the test model because it is arguably one of the most common and most painful procedures endured by the animals. Forty-eight, 6–8-month-old Brahman bulls were surgically castrated after random assignment to six different treatment groups (n = 8): no castration Control (NC); castration (C); castration with post-operative meloxicam (CMpost-op); castration with lignocaine (CL); castration with lignocaine and post-operative meloxicam (CLMpost-op); castration with pre-operative meloxicam (CMpre-op). Serial measures of weight, blood cortisol concentrations, balk score, crush score, and daily activity (steps taken, number and duration of rest bouts) were taken. Linear mixed modelling was used to compare experimental groups. Bulls that were castrated and did not receive post-operative meloxicam (C and CL) had significantly lower average weights at all time points (Days 0–13, P < 0.001) of 170.9 kg and 168.6 kg, respectively, than those that did (CMpost-op and CLMpost-op) at 174.7 kg and 173.7 kg, respectively. When lignocaine was not administered before castration, Day 1 post-operative cortisol concentrations were significantly lower when post-operative meloxicam was provided than when it was not (CMpost-op: 47.2 nmol/L vs C: 65.5 nmol/L). When post-operative meloxicam was not given, animals that were given lignocaine before castration had significantly lower cortisol concentrations than those that received no lignocaine (CL: 52.7 nmol/L vs C: 65.5 nmol/L). Animals that were given pre-operative meloxicam had, on average, significantly lower Day 1 post-operative cortisol concentrations than animals that received no lignocaine or meloxicam (CMpre-op: 44.8 nmol/L vs C: 65.5 nmol/L). Analysis of Day 1 (the day following castration) data showed that animals that were given pre-operative meloxicam (CMpre-op) were significantly more active than animals in all other treatment groups (P = 0.038). It was concluded that 6–8-month old, Bos indicus bulls benefit from the administration of both lignocaine before surgery and peri-operative meloxicam. The analgesic methods used are readily adoptable by industry with respect to cost, efficiency and degree of technical skill required.

A comparison of early and late treatments on allodynia and its chronification in experimental neuropathic pain

Background Surgeries causing nerve injury can result in chronic neuropathic pain, which is clinically managed by using antidepressant or anticonvulsant drugs. Currently, there is a growing interest for investigating preemptive treatments that would prevent this long-term development of neuropathic pain. Our aim was to compare analgesic drugs using two distinct treatment modalities: either treatment onset at surgery time or following a couple of weeks of neuropathic pain. Methods In male C57BL/6J mice, neuropathic pain was induced by cuffing the sciatic nerve, and allodynia was assessed using von Frey filaments. We tested the effect of anticonvulsants (gabapentin 10 mg/kg and carbamazepine 40 mg/kg), antidepressants (desipramine 5 mg/kg, duloxetine 10 mg/kg, and fluoxetine 10 mg/kg), dexamethasone (2 mg/kg), and ketamine (15 mg/kg). Drugs were injected daily or twice a day, starting either at surgery time or on day 25 postsurgery (15 days of treatment for antidepressants and 10 days for other drugs). Results Ketamine was the only effective treatment during the early postsurgical period. Although early anticonvulsant treatment was not immediately effective, it prevented chronification of allodynia. When treatments started at day 25 postsurgery, desipramine, duloxetine, and anticonvulsants suppressed the mechanical allodynia. Conclusions Our data show that allodynia measured in experimental neuropathic pain model likely results from a combination of different processes (early vs. late allodynia) that display different sensitivity to treatments. We also propose that early anticonvulsant treatment with gabapentin or carbamazepine may have a prophylactic effect on the chronification of allodynia following nerve injury.

Is there a reasonable excuse for not providing post-operative analgesia when using animal models of peripheral neuropathic pain for research purposes?

Introduction

The induction of neuropathic pain-like behaviors in rodents often requires surgical intervention. This engages acute nociceptive signaling events that contribute to pain and stress post-operatively that from a welfare perspective demands peri-operative analgesic treatment. However, a large number of researchers avoid providing such care based largely on anecdotal opinions that it might interfere with model pathophysiology in the longer term.

Objectives

To investigate effects of various peri-operative analgesic regimens encapsulating different mechanisms and duration of action, on the development of post-operative stress/welfare and pain-like behaviors in the Spared Nerve Injury (SNI)-model of neuropathic pain.

Methods

Starting on the day of surgery, male Sprague-Dawley rats were administered either vehicle (s.c.), carprofen (5.0mg/kg, s.c.), buprenorphine (0.1mg/kg s.c. or 1.0mg/kg p.o. in Nutella^®), lidocaine/bupivacaine mixture (local irrigation) or a combination of all analgesics, with coverage from a single administration, and up to 72 hours. Post-operative stress and recovery were assessed using welfare parameters, bodyweight, food-consumption, and fecal corticosterone, and hindpaw mechanical allodynia was tested for assessing development of neuropathic pain for 28 days.

Results

None of the analgesic regimes compromised the development of mechanical allodynia. Unexpectedly, the combined treatment with 0.1mg/kg s.c. buprenorphine and carprofen for 72 hours and local irrigation with lidocaine/bupivacaine, caused severe adverse effects with peritonitis. This was not observed when the combination included a lower dose of buprenorphine (0.05mg/kg, s.c.), or when buprenorphine was administered alone (0.1mg/kg s.c. or 1.0mg/kg p.o.) for 72 hours. An elevated rate of wound dehiscence was observed especially in the combined treatment groups, underlining the need for balanced analgesia. Repeated buprenorphine injections had positive effects on body weight the first day after surgery, but depressive effects on food intake and body weight later during the first week.

Conclusion

Post-operative analgesia does not appear to affect established neuropathic hypersensitivity outcome in the SNI model.

Poorly controlled postoperative pain: prevalence, consequences, and prevention

This review provides an overview of the clinical issue of poorly controlled postoperative pain and therapeutic approaches that may help to address this common unresolved health-care challenge. Postoperative pain is not adequately managed in greater than 80% of patients in the US, although rates vary depending on such factors as type of surgery performed, analgesic/anesthetic intervention used, and time elapsed after surgery. Poorly controlled acute postoperative pain is associated with increased morbidity, functional and quality-of-life impairment, delayed recovery time, prolonged duration of opioid use, and higher health-care costs. In addition, the presence and intensity of acute pain during or after surgery is predictive of the development of chronic pain. More effective analgesic/anesthetic measures in the perioperative period are needed to prevent the progression to persistent pain. Although clinical findings are inconsistent, some studies of local anesthetics and nonopioid analgesics have suggested potential benefits as preventive interventions. Conventional opioids remain the standard of care for the management of acute postoperative pain; however, the risk of opioid-related adverse events can limit optimal dosing for analgesia, leading to poorly controlled acute postoperative pain. Several new opioids have been developed that modulate μ-receptor activity by selectively engaging intracellular pathways associated with analgesia and not those associated with adverse events, creating a wider therapeutic window than unselective conventional opioids. In clinical studies, oliceridine (TRV130), a novel μ-receptor G-protein pathway-selective modulator, produced rapid postoperative analgesia with reduced prevalence of adverse events versus morphine.

Multimodal analgesia in moderate-to-severe pain: a role for a new fixed combination of dexketoprofen and tramadol

BACKGROUND

Untreated and under-treated pain represent one of the most pervasive health problems, which is worsening as the population ages and accrues risk for pain. Multiple treatment options are available, most of which have one mechanism of action, and cannot be prescribed at unlimited doses due to the ceiling of efficacy and/or safety concerns. Another limitation of single-agent analgesia is that, in general, pain is due to multiple causes. Combining drugs from different classes, with different and complementary mechanism(s) of action, provides a better opportunity for effective analgesia at reduced doses of individual agents. Therefore, there is a potential reduction of adverse events, often dose-related. Analgesic combinations are recommended by several organizations and are used in clinical practice. Provided the two agents are combined in a fixed-dose ratio, the resulting medication may offer advantages over extemporaneous combinations.

CONCLUSIONS

Dexketoprofen/tramadol (25 mg/75 mg) is a new oral fixed-dose combination offering a comprehensive multimodal approach to moderate-to-severe acute pain that encompasses central analgesic action, peripheral analgesic effect and anti-inflammatory activity, together with a good tolerability profile. The analgesic efficacy of dexketoprofen/tramadol combination is complemented by a favorable pharmacokinetic and pharmacodynamic profile, characterized by rapid onset and long duration of action. This has been well documented in both somatic- and visceral-pain human models. This review discusses the available clinical evidence and the future possible applications of dexketoprofen/tramadol fixed-dose combination that may play an important role in the management of moderate-to-severe acute pain.

Assessment and management of pain in pediatric otolaryngology

INTRODUCTION

Pain is a disease by itself and it's a public health concern of major implication in children, not just because of the emotional component of the child and his family, but also due to the potential morbidity and mortality involving it. A proper assessment of pain it's a challenge in the pediatric population, due to their lack of understanding and verbalization of hurt. Additionally, a satisfactory treatment of pediatric pain can be arduous due to a lack of clinical knowledge, insufficient pediatric research, and the fear to opioid side effects and addiction.

OBJECTIVES

The aim of this review is to address the current definitions of pain, its physiological mechanisms and the consequences of its inadequate management, as well as, to guide the clinicians in the assessment and management of pain in the pediatric population at otolaryngology services.

METHODOLOGY

Narrative review by selective MeSH search terms: Children, Pediatrics, Otolaryngology, Pain measurement, Pain Management, Analgesics and Analgesia, from databases: MEDLINE/PubMed, Cochrane, ISI, Current Contents, Scielo and LILACS, between January 2000 and May 2016.

RESULTS

129 articles were reviewed according to the requirements of the objectives. Pain measurement is a challenge in children as there are no physical signs that constitute an absolute or specific indicator of pain, and its diagnosis must rely on physiological, behavioral and self-report methods. Regarding treatment, a suitable alternative are the non-pharmacological cognitive/behavioral therapies helped by pharmacological therapies tailored to the severity of pain and the child's age. We provide evidence-based recommendations on pain treatment, including non-opioid analgesics, opioid analgesics and adjuvant medicines to improve the management of pain in children in otolaryngology services.

CONCLUSIONS

We present a global review about assessment and management of pain in pediatric otolaryngology, which leads to future specific reviews on each topic. Research gaps on pain assessment and pharmacological interventions in neonates, infants and children are very wide and it should be promoted ethical and safe research on pain control in this population.

Antidepressant Drugs for Postsurgical Pain: Current Status and Future Directions

Current treatments for postsurgical pain are often inadequate and adverse effects are substantial such that residual pain and/or side effects impair recovery. The recognition of analgesic efficacy with antidepressant drugs for chronic pain suggests the potential for efficacy in acute postsurgical pain. As reviewed here, current evidence suggests that approximately half of previous trials suggest efficacy of various antidepressants for acute postoperative pain. However, most trials are older with deficiencies including: lack of designation of a primary outcome, no assessment of movement-evoked pain, small size and limited safety assessment. Only one of three trials addressing prevention of chronic postsurgical pain suggested any efficacy; however, the evidence base for this indication is limited. Thus, current evidence does not yet support routine use of any one specific antidepressant for treatment of acute, or prevention of chronic, postsurgical pain. However, limitations in available trials are such that one cannot yet rule out the possibility that one or more antidepressant drugs may provide benefit in specific populations. Therefore, future larger trials should explore optimal dosing and duration of antidepressant treatment, procedure specificity, safety evaluation, and assessment of movement-evoked pain.

Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias

The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia.

Will the Real Benefits of Single-Shot Interscalene Block Please Stand Up? A Systematic Review and Meta-Analysis

BACKGROUND

Interscalene block (ISB) can provide pain relief after shoulder surgery, but a reliable quantification of its analgesic benefits is lacking. This meta-analysis examines the effect of single-shot ISB on analgesic outcomes during the first 48 hours after shoulder surgery.

METHODS

We retrieved randomized and quasirandomized controlled trials examining the analgesic benefits of ISB compared with none in shoulder surgery. Severity of postoperative pain measured on a visual analog scale (10 cm scale, 0 = no pain, 10 = worst pain) at rest at 24 hours was the designated primary outcome. Secondary outcomes included pain severity at rest and with motion at 2, 4, 6, 8, 12, 16, 32, 36, 40, and 48 hours postoperatively. Opioid consumption, postoperative nausea and vomiting, patient satisfaction with pain relief, and postanesthesia care unit and hospital discharge time were also assessed.

RESULTS

A total of 23 randomized controlled trials, including 1090 patients, were analyzed. Patients in the ISB group had more severe postoperative pain at rest by a weighed mean difference (95% confidence interval) of 0.96 cm (0.08-1.83; P = 0.03) at 24 hours compared with no ISB, but there was no difference in pain severity beyond that point. The duration of pain relief at rest and with motion after ISB were 8 and 6 hours, respectively, with a corresponding weighed mean difference in visual analog scale pain scores (99% confidence interval) of -1.59 cm (-2.60 to -0.58) and -2.20 cm (-4.34 to -0.06), respectively, with no additional pain relief benefits beyond these points. ISB reduced postoperative opioid consumption up to 12 hours, decreased postoperative nausea and vomiting at 24 hours, and expedited postanesthesia care unit and hospital discharge. The type, dose, and volume of local anesthetic used did not affect the results.

CONCLUSIONS

ISB can provide effective analgesia up to 6 hours with motion and 8 hours at rest after shoulder surgery, with no demonstrable benefits thereafter. Patients who receive an ISB can suffer rebound pain at 24 hours but later experience similar pain severity compared with those who do not receive an ISB. ISB can also provide an opioid-sparing effect and reduce opioid-related side effects in the first 12 and 24 hours postoperatively, respectively. These findings are useful to inform preoperative risk-benefit discussions regarding ISB for shoulder surgery.

Pain Part 3: Acute Orofacial Pain

Acute trigeminal pain is a common presentation in the dental surgery, with a reported 22% of the US adult population experiencing orofacial pain more than once during a 6-month period. This article discusses the mechanisms underlying the pain experience, diagnosis and subsequent management of acute trigeminal pain, encompassing pre-, peri- and post-operative analgesia. The dental team spend most of their working lives managing patients and acute pain. The patient may present to the clinician in existing pain, which may often provide a diagnostic challenge. Prevention and managing intra-operative and post-surgical pain are implicit in providing your patient with optimum care. CPD/CLINICAL RELEVANCE: This paper aims to provide an overview of conditions that may present with acute orofacial pain and their management using the most recent evidence base. Intra-operative and post-surgical pain management are also scrutinized and evidence based treatment is recommended.

IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block

Background

Perineural and IV dexmedetomidine have each been suggested to prolong the duration of analgesia when administered in conjunction with peripheral nerve blocks. In the first randomized, triple-masked, placebo-controlled trial to date, the authors aimed to define and compare the efficacy of perineural and IV dexmedetomidine in prolonging the analgesic duration of single-injection interscalene brachial plexus block (ISB) for outpatient shoulder surgery.

Methods

Ninety-nine patients were randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 μg/kg dexmedetomidine administered perineurally (DexP group), intravenously (DexIV group), or none (control group). The authors sequentially tested the joint hypothesis that dexmedetomidine prolongs the duration of analgesia and reduces the 24-h cumulative postoperative morphine consumption. Motor blockade, pain severity, hemodynamic variations, opioid-related side effects, postoperative neurologic symptoms, and patient satisfaction were also evaluated.

Results

Ninety-nine patients were analyzed. The duration of analgesia was 10.9 h (10.0 to 11.8 h) and 9.8 h (9.0 to 10.6 h) for the DexP and DexIV groups, respectively, compared with 6.7 h (5.6 to 7.8) for the control group (P &lt; 0.001). Dexmedetomidine also reduced the 24-h cumulative morphine consumption to 63.9 mg (58.8 to 69.0 mg) and 66.2 mg (60.6 to 71.8 mg) for the DexP and DexIV groups, respectively, compared with 81.9 mg (75.0 to 88.9 mg) for the control group (P &lt; 0.001). DexIV was noninferior to DexP for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade.

Conclusion

Both perineural and IV dexmedetomidine can effectively prolong the ISB analgesic duration and reduce the opioid consumption without prolonging motor blockade.

Options for perioperative pain management in neurosurgery

Moderate-to-severe pain following neurosurgery is common but often does not get attention and is therefore underdiagnosed and undertreated. Compounding this problem is the traditional belief that neurosurgical pain is inconsequential and even dangerous to treat. Concerns about problematic effects associated with opioid analgesics such as nausea, vomiting, oversedation, and increased intracranial pressure secondary to elevated carbon dioxide tension from respiratory depression have often led to suboptimal postoperative analgesic strategies in caring for neurosurgical patients. Neurosurgical patients may have difficulty or be incapable of communicating their need for analgesics due to neurologic deficits, which poses an additional challenge. Postoperative pain control should be a priority, because pain adversely affects recovery and patient outcomes. Inconsistent practices and the quality of current analgesic strategies for neurosurgical patients still leave room for improvement. Given the complexity of postoperative pain management for these patients, multimodal strategies are often required to optimize pain control and at the same time limit undesired side effects.

Ten Myths and Misconceptions Regarding Pain Management in the ICU

OBJECTIVES

The aim of this article is to expose common myths and misconceptions regarding pain assessment and management in critically ill patients that interfere with effective care. We comprehensively review the literature refuting these myths and misconceptions and describe evidence-based strategies for improving pain management in the ICU.

DATA SOURCES

Current peer-reviewed academic journals, as well as standards and guidelines from professional societies.

STUDY SELECTION

The most current evidence was selected for review based on the highest degree of supportive evidence.

DATA EXTRACTION

Data were obtained via medical search databases, including OvidSP, and the National Library of Medicine's MEDLINE database via PubMed.

DATA SYNTHESIS

After a comprehensive literature review, conclusions were drawn based on the strength of evidence and the most current understanding of pain management practices in ICU.

CONCLUSIONS

Myths and misconceptions regarding management of pain in the ICU are prevalent. Review of current evidence refutes these myths and misconceptions and provides insights and recommendations to ensure best practices.

Preventive analgesia and novel strategies for the prevention of chronic post-surgical pain

Chronic post-surgical pain (CPSP) is a serious complication of major surgery that can impair a patient's quality of life. The development of CPSP is a complex process which involves biologic, psychosocial, and environmental mechanisms that have yet to be fully understood. Currently perioperative pharmacologic interventions aim to suppress and prevent sensitization with the aim of reducing pain and analgesic requirement in acute as well as long-term pain . Despite the detrimental effects of CPSP on patients, the body of literature focused on treatment strategies to reduce CPSP remains limited and continues to be understudied. This article reviews the main pharmacologic candidates for the treatment of CPSP, discusses the future of preventive analgesia, and considers novel strategies to help treat acute post-operative pain and lessen the risk that it becomes chronic. In addition, this article highlights important areas of focus for clinical practice including: multimodal management of CPSP patients, psychological modifiers of the pain experience, and the development of a Transitional Pain Service specifically designed to manage patients at high risk of developing chronic post-surgical pain.