Challenges in acute pain management

Oliceridine for the Management of Moderate to Severe Acute Postoperative Pain: A Narrative Review

Despite current advances in acute postoperative pain management, prevalence remains high. Inadequate treatment could lead to poor outcomes and even progression to chronic pain. Opioids have traditionally been the mainstay for treatment of moderate to severe acute pain. However, their use has been associated with opioid-related adverse events (ORAEs), such as respiratory depression, sedation, nausea, vomiting, pruritus, and decreased bowel motility. In addition, their liberal use has been implicated in the current opioid epidemic. As a result, there has been renewed interest in multimodal analgesia to target different mechanisms of action in order to achieve a synergistic effect and minimize opioid usage. Oliceridine is a novel mu-opioid receptor agonist that is part of a new class of biased ligands that selectively activate G-protein signaling and downregulate β-arrestin recruitment. Since G-protein signaling has been associated with analgesia while β-arrestin recruitment has been associated with ORAEs, there is potential for a wider therapeutic window. In this review, we will discuss the clinical evidence behind oliceridine and its potential role in acute postoperative pain management. We have systematically searched the PubMed database using the keywords oliceridine, olinvyk, and trv130. All articles identified were reviewed and evaluated, and all clinical trials were included.

V-NOTES hysterectomy under spinal anaesthesia: A pilot study

Background: Spinal anaesthesia has not been widely adopted for laparoscopic surgeries until now. There are a few studies that have shown that spinal anaesthesia is at least as safe as general anaesthesia. The need for additional analgesics can be reduced by utilising early postoperative analgesic effects of spinal anaesthesia, and maximum benefit can be obtained from minimally invasive approaches when V-NOTES surgery is performed under spinal anaesthesia. Objective: Combining V-NOTES with spinal anaesthesia to improve minimally invasive surgical techniques and provide maximum benefit to patients. Materials and methods: Patients who were found to have benign pelvic organ pathologies, required a hysterectomy and were considered suitable for V-NOTES hysterectomy under spinal anaesthesia were included in this study. Spinal anaesthesia was achieved with 12.5 mg 0.5% hyperbaric bupivacaine in the sitting position. Perioperative events and complications related to spinal anaesthesia were noted. Postoperatively, the pain was evaluated using a visual analogue scale at the 6th, 12th, and 24th hours. Main outcome measures: To evaluate the feasibility and safety of spinal anaesthesia in VNOTES hysterectomy and to increase the advantages of minimally invasive surgical procedures. Results: No conversion to conventional laparoscopy or laparotomy was required in all six operated patients. Conversion from spinal anaesthesia to general anaesthesia was unnecessary, and no major perioperative incident occurred in any of the cases. Conclusion: In the current study by our team, we demonstrated that V-NOTES hysterectomy could be performed safely under spinal anaesthesia in well-selected patients. The need for additional analgesics can be reduced by utilising early postoperative analgesic effects of spinal anaesthesia, and maximum benefit can be obtained from minimally invasive approaches when VNOTES surgery is performed under spinal anaesthesia. What is new? V-NOTES hysterectomy could be performed safely under spinal anaesthesia in well-selected patients.

Epigallocatechin-3-Gallate Modulates Postoperative Pain by Regulating Biochemical and Molecular Pathways

Treating postoperative (PO) pain is a clinical challenge. Inadequate PO pain management can lead to worse outcomes, for example chronic post-surgical pain. Therefore, acquiring new information on the PO pain mechanism would increase the therapeutic options available. In this paper, we evaluated the role of a natural substance, epigallocatechin-3-gallate (EGCG), on pain and neuroinflammation induced by a surgical procedure in an animal model of PO pain. We performed an incision of the hind paw and EGCG was administered for five days. Mechanical allodynia, thermal hyperalgesia, and motor dysfunction were assessed 24 h, and three and five days after surgery. At the same time points, animals were sacrificed, and sera and lumbar spinal cord tissues were harvested for molecular analysis. EGCG administration significantly alleviated hyperalgesia and allodynia, and reduced motor disfunction. From the molecular point of view, EGCG reduced the activation of the WNT pathway, reducing WNT3a, cysteine-rich domain frizzled (FZ)1 and FZ8 expressions, and both cytosolic and nuclear β-catenin expression, and the noncanonical β-catenin–independent signaling pathways, reducing the activation of the NMDA receptor subtype NR2B (pNR2B), pPKC and cAMP response element-binding protein (pCREB) expressions at all time points. Additionally, EGCG reduced spinal astrocytes and microglia activation, cytokines overexpression and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) pathway, downregulating inducible nitric oxide synthase (iNOS) activation, cyclooxygenase 2 (COX-2) expression, and prostaglandin E2 (PGE2) levels. Thus, EGCG administration managing the WNT/β-catenin signaling pathways modulates PO pain related neurochemical and inflammatory alterations.

The Effectiveness of Virtual Reality in Managing Acute Pain and Anxiety for Medical Inpatients: Systematic Review

Background

Virtual reality is increasingly being utilized by clinicians to facilitate analgesia and anxiolysis within an inpatient setting. There is however, a lack of a clinically relevant review to guide its use for this purpose.

Objective

To systematically review the current evidence for the efficacy of virtual reality as an analgesic in the management of acute pain and anxiolysis in an inpatient setting.

Methods

A comprehensive search was conducted up to and including January 2019 on PubMed, Ovid Medline, EMBASE, and Cochrane Database of Systematic reviews according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Search terms included virtual reality, vr, and pain. Primary articles with a focus on acute pain in the clinical setting were considered for the review. Primary outcome measures included degree of analgesia afforded by virtual reality therapy, degree of anxiolysis afforded by virtual reality therapy, effect of virtual reality on physiological parameters, side effects precipitated by virtual reality, virtual reality content type, and type of equipment utilized.

Results

Eighteen studies were deemed eligible for inclusion in this systematic review; 67% (12/18) of studies demonstrated significant reductions in pain with the utilization of virtual reality; 44% (8/18) of studies assessed the effects of virtual reality on procedural anxiety, with 50% (4/8) of these demonstrating significant reductions; 28% (5/18) of studies screened for side effects with incidence rates of 0.5% to 8%; 39% (7/18) of studies evaluated the effects of virtual reality on autonomic arousal as a biomarker of pain, with 29% (2/7) demonstrating significant changes; 100% (18/18) of studies utilized a head mounted display to deliver virtual reality therapy, with 50% being in active form (participants interacting with the environment) and 50% being in passive form (participants observing the content only).

Conclusions

Available evidence suggests that virtual reality therapy can be applied to facilitate analgesia for acute pain in a variety of inpatient settings. Its effects, however, are likely to vary by patient population and indication. This highlights the need for individualized pilot testing of virtual reality therapy’s effects for each specific clinical use case rather than generalizing its use for the broad indication of facilitating analgesia. In addition, virtual reality therapy has the added potential of concurrently providing procedural anxiolysis, thereby improving patient experience and cooperation, while being associated with a low incidence of side effects (nausea, vomiting, eye strain, and dizziness). Furthermore, findings indicated a head mounted display should be utilized to deliver virtual reality therapy in a clinical setting with a slight preference for active over passive virtual reality for analgesia. There, however, appears to be insufficient evidence to substantiate the effect of virtual reality on autonomic arousal, and this should be considered at best to be for investigational uses, at present.

The Protective Effects of Pre- and Post-Administration of Micronized Palmitoylethanolamide Formulation on Postoperative Pain in Rats

Background: Postoperative pain (PO) is a common form of acute pain. Inadequate PO treatment is an important health problem, as it leads to worse outcomes, such as chronic post-surgical pain. Therefore, it is necessary to acquire new knowledge on PO mechanisms to develop therapeutic options with greater efficacy than those available today and to lower the risk of adverse effects. For this reason, we evaluated the ability of micronized palmitoylethanolamide (PEA-m) to resolve the pain and inflammatory processes activated after incision of the hind paw in an animal model of PO. Methods: The animals were subjected to surgical paw incision and randomized into different groups. PEA-m was administered orally at 10 mg/kg at different time points before or after incision. Results: Our research demonstrated that the pre- and post-treatment with PEA-m reduced the activation of mast cells at the incision site and the expression of its algogenic mediator nerve growth factor (NGF) in the lumbar spinal cord. Furthermore, again at the spinal level, it was able to decrease the activation of phospho-extracellular signal-regulated kinases (p-ERK), ionized calcium binding adaptor molecule 1 (Iba1), glial fibrillary acidic protein (GFAP), and the expression of brain-derived neurotrophic factor (BDNF). PEA-m also reduced the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) spinal pathway, showing a protective effect in a rat model of PO. Conclusion: The results obtained reinforce the idea that PEA-m may be a potential treatment for the control of pain and inflammatory processes associated with PO. In addition, pre- and post-treatment with PEA-m is more effective than treatment alone after the surgery and this limits the time of taking the compound and the abuse of analgesics.

Factors associated with chronic pain following breast reconstruction in Japanese women

Chronic pain after breast surgery including breast reconstruction is a major concern for patients. However, the factors associated with chronic pain after breast surgery are uncertain in Japanese population. The aim of this study was to identify patient-specific and medical/surgical factors that predict chronic pain after breast surgery in Japanese patients. The subjects were 189 Japanese women undergoing breast surgery including tissue expander/implant (TE/implant), deep inferior epigastric perforator (DIEP) procedures and mastectomy only. Pain was assessed at one year postoperatively using a validated survey instrument: the Japanese version of the Short-Form McGill Pain Questionnaire (SF-MPQ-JV). A multiple linear regression model was used to examine the relationships of clinical factors with postoperative pain. Surveys were completed by 141 subjects. A younger age (p = .04) and bilateral procedures (p < .05) were both closely associated with the extent of increased postoperative pain at 1 year using the MPQ-Total pain rating. Compared to total mastectomy only, TE/implant procedures showed a significantly lower visual analog scale (VAS) (p = .04) and present pain index (PPI) (p = .03) scores. No factor related to chronic pain was also significantly related to the frequency of pain medication use postoperatively or the effect of social life of the patients. This study identified patients at risk for greater chronic pain after breast surgery. These findings will allow surgeons to improve patient comfort, reduce clinical morbidity and enhance patient satisfaction with their surgical outcome. Abbreviations: BMI: body mass index; CI: confidence interval; DIEP: deep inferior epigastric perforator flap; MPQ: McGill pain questionnaire; PPI: present pain index; SD: standard deviation; SF-MPQ-JV: Japanese version of the short-form McGill pain questionnaire; TE: tissue expander; VAS: visual analog scale.

Which agent should be used to reduce ischemia-reperfusion injury after testicular torsion: a comparative animal experiment

INTRODUCTION

Testicular torsion is an acute urological emergency that causes severe damage of testis. In order to prevent testicular damage, early diagnosis and surgical intervention is essential. Also pain management in both pre-operative and postoperative periods remains a challenging entity.

OBJECTIVE

In this study, we aimed to determine the possible positive effects of three different analgesics (ibuprofen, metamizole, and paracetamol), which are widely used in clinical practice on testicular tissue, in addition to pain control.

STUDY DESIGN

Forty prepubertal rats (180-210 g) were divided into five experimental groups. Group 1 was sham group in which the left testis was brought out through a scrotal incision and then replaced in the scrotum without torsion. Group 2 was control group (only 0.9% NaCl was applied). Also in group 3, paracetamol, in group 4, ibuprofen, and in group 5, metamizole sodium was applied 1 h after the torsion. Torsion duration was planned as 4 h for all groups.

RESULTS

In the biochemical evaluation, malondialdehyde (MDA), myeloperoxidase (MPO), and total nitrate (NO) levels were measured in the testicular tissue. All groups were compared with group 2 (control group). In group 3, although the MDA level was lower and the MPO level was found to be higher, these were not statistically significant. In group 4, the NO level was low but statistically significant. Histological findings were evaluated due to Cosentino's classification, and the scores of group 4 were better than all groups.

DISCUSSION

In this study, severe damage was observed at the end of torsion period of 4 h. This is in line with previous published data. The beneficial effects of all three drugs have been observed.

CONCLUSIONS

Biochemical results did not clearly highlight any agents. According to pathology results, metamizole was better than paracetamol and the most ideal analgesic preparation was observed as ibuprofen.

A Dedicated Acute Pain Service Is Associated With Reduced Postoperative Opioid Requirements in Patients Undergoing Cytoreductive Surgery With Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND:

The Acute Pain Service (APS) was initially introduced to optimize multimodal postoperative pain control. The aim of this study was to evaluate the association between the implementation of an APS and postoperative pain management and outcomes for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

METHODS:

In this propensity-matched retrospective cohort study, we performed a before–after study without a concurrent control group. Outcomes were compared among patients undergoing CRS-HIPEC when APS was implemented versus historical controls (non-APS). The primary objective was to determine if there was a decrease in median total opioid consumption during postoperative days 0–3 among patients managed by the APS. Secondary outcomes included opioid consumption on each postoperative day (0–6), time to ambulation, time to solid intake, and hospital length of stay.

RESULTS:

After exclusion, there were a total of 122 patients, of which 51 and 71 were in the APS and non-APS cohort, respectively. Between propensity-matched groups, the median (quartiles) total opioid consumption during postoperative days 0–3 was 27.5 mg intravenous morphine equivalents (MEQs) (7.6–106.3 mg MEQs) versus 144.0 mg MEQs (68.9–238.3 mg MEQs), respectively. The median difference was 80.8 mg MEQs (95% confidence interval, 46.1–124.0; P < .0001). There were statistically significant decreases in time to ambulation and time to solid diet intake in the APS cohort.

CONCLUSIONS:

After implementing the APS, CRS-HIPEC patients had decreased opioid consumption by >50%, as well as shorter time to ambulation and time to solid intake. Implementation of an APS may improve outcomes in CRS-HIPEC patients.

The need for novel strategies to address postoperative pain associated with cardiac surgery: A commentary and introduction to "SMArTVIEW"

Background: With coronary heart disease affecting over 2.4 million Canadians, annual cardiac and major vascular surgery rates are on the rise. Unrelieved postoperative pain is among the top five causes of hospital readmission following surgery; little is done to address this postoperative complication. Barriers to effective pain assessment and management following cardiac and major vascular surgery have been conceptualized on patient, health care provider, and system levels. Purpose: In this commentary, we review common patient, health care provider, and system-level barriers to effective postoperative pain assessment and management following cardiac and major vascular surgery. We then outline the SMArTVIEW intervention, with particular attention to components designed to optimize postoperative pain assessment and management. Methods: In conceptualizing the SMArTVIEW intervention design, we sought to address a number of these barriers by meeting the following design objectives: (1) orchestrating a structured process for regular postoperative pain assessment and management; (2) ensuring adequate clinician preparation for postoperative pain assessment and management in the context of virtual care; and (3) enfranchising patients to become active self-managers and to work with their health care providers to manage their pain postoperatively. Conclusions: Innovative approaches to address these barriers are a current challenge to health care providers and researchers alike. SMArTVIEW is spearheading this paradigm shift within clinical research to address barriers that impair effective postoperative pain management by actively engaging health care providers and patients in an accessible format (i.e., digital health solution) to give primacy to the need of postoperative pain assessment and management following cardiac and major vascular surgery.

Biological Screening of Novel Structural Analog of Celecoxib as Potential Anti-Inflammatory and Analgesic Agent

Background and objectives: The clinical use of non-steroidal anti-inflammatory drugs is limited due to high incidence of adverse drug reactions. The pyrrole heterocycle is included in the chemical structure of a number of drugs with various activities and shows relatively good tolerability and safety. The objectives of our study were to evaluate the analgesic and anti-inflammatory activity, as well as possible organ toxicity, of 2-[3-acetyl-5-(4-chloro-phenyl)-2-methyl-pyrrol-1-yl]-3-(1H-indol-3-yl)-propionic acid (compound 3g), a novel N-pyrrolylcarboxylic acid structurally similar to celecoxib. Materials and methods: All experiments were performed on 6-week-old male Wistar rats divided into parallel groups (n = 8). Antinociception was assessed using animal pain models with thermal and chemical stimuli (paw withdrawal, tail-flick, and formalin tests). Criteria for the analgesic effect were increased latency in the paw withdrawal and tail-flick tests and decreased paw licking time in the formalin test compared to animals treated with saline (control). Anti-inflammatory activity was measured using a carrageenan-induced paw edema model; the criterion for anti-inflammatory effect was decreased edema compared to control. Blood samples were obtained after animals were sacrificed to assess possible organ toxicity. Statistical analysis was performed with IBM SPSS 20.0. Results: 2-[3-Acetyl-5-(4-chloro-phenyl)-2-methyl-pyrrol-1-yl]-3-(1H-indol-3-yl)-propionic acid had analgesic action against chemical stimulus after single and multiple administration and against thermal stimulus after single administration. Compound 3g significantly suppressed carrageenan-induced paw edema after both single and continuous administration. After continuous administration, hematological tests showed that compound 3g decreased leukocyte and platelet levels and elevated serum creatinine levels. Conclusions: Antinociception with the tested compound is most likely mediated by spinal, peripheral, and anti-inflammatory mechanisms. Possible tolerance of the analgesic action at the spinal level develops after continuous administration. Anti-inflammatory activity is significant and probably the leading cause of antinociception. After multiple administration, compound 3g showed signs of potential nephrotoxicity and antiplatelet activity, as well as suppression of leukocyte levels.

Variation of Opioid Prescribing Patterns among Patients undergoing Similar Surgery on the Same Acute Care Surgery Service of the Same Institution: Time for Standardization?

BACKGROUND

Diversion of unused prescription opioids is a major contributor to the current United States opioid epidemic. We aimed to study the variation of opioid prescribing in emergency surgery.

METHODS

Between October 2016 and March 2017, all patients undergoing laparoscopic appendectomy, laparoscopic cholecystectomy, or inguinal hernia repair in the acute care surgery service of 1 academic center were included. For each patient, we systematically reviewed the electronic medical record and the prescribing pharmacy platform to identify: (1) history of opioid abuse, (2) opioid intake 3 months preoperatively, (3) number of opioid pills prescribed, (4) prescription of nonopioid pain medications (eg, acetaminophen, ibuprofen), and (5) the need for opioid prescription refills. The mean and range of opioid pills prescribed, as well as their oral morphine equivalent, were calculated.

RESULTS

A total of 255 patients were included (43.5% laparoscopic appendectomy, 44.3% laparoscopic cholecystectomy, and 12.1% inguinal hernia repair). The mean age was 47.5 years, 52.1% were female, 11.4% had a history of opioid use, and 92.5% received opioid prescriptions upon hospital discharge. Only 70.9% of patients were instructed to use nonopioid pain medications. The mean and range of opioid pills prescribed were 17.4; 0-56 (laparoscopic appendectomy), 17.1; 0-75 (laparoscopic cholecystectomy), and 20.9; 0-50 (inguinal hernia repair), while the range of prescribed oral morphine equivalent was 0-600 mg for laparoscopic appendectomy/laparoscopic cholecystectomy and 0-375 mg for inguinal hernia repair. No patients required any opioid medication refills.

CONCLUSION

Even within the same surgical service, wide variation of opioid prescription was observed. Guidelines that standardize pain management may help prevent opioid overprescribing.

A prospective, randomized, double-blind, placebo-controlled trial of acute postoperative pain treatment using opioid analgesics with intravenous ibuprofen after radical cervical cancer surgery

This study assessed the efficacy and tolerability of intravenous ibuprofen in the improvement of post-operative pain control and the reduction of opioid usage. Patients were randomly divided into placebo, ibuprofen 400 mg and ibuprofen 800 mg groups. All patients received patient-controlled intravenous morphine analgesia after surgery. The first dose of study drugs was administered intravenously 30 min before the end of surgery and then every 6 hours, for a total of 8 doses after surgery. The primary endpoint of this study was the mean amount of morphine used during the first 24 hours after surgery. Morphine use was reduced significantly in the ibuprofen 800 mg group compared with the placebo group (P = 0.04). Tramadol use was reduced significantly in the ibuprofen 400 mg and ibuprofen 800 mg groups compared with the placebo group (P < 0.01). The area under the curve of visual analog scale pain ratings was not different between groups. Safety assessments and side effects were not different between the three groups. Intravenous ibuprofen 800 mg was associated with a significant reduction in morphine requirements, and it was generally well tolerated for postoperative pain management in patients undergoing radical cervical cancer surgery.

Incidence of children at risk for obstructive sleep apnea undergoing common day surgery procedures

OBJECTIVE

The purpose of this study was to evaluate the prevalence of sleep-related breathing disorders (SRBD) in children undergoing elective day surgery procedures.

METHODS

A validated Pediatric Sleep Questionnaire (PSQ) was distributed to the parents of children aged 2months to 18 years who met inclusion criteria and were undergoing urologic, otolaryngologic, and general surgical day surgery procedures a 3-month period of time. The prevalence of children at risk for pediatric SRBD was determined from PSQ results.

RESULTS

From a total of 288 PSQ Questionnaires, 9.1% of urology, 11.1% of general surgery, and 51.9% of otolaryngology patients admitted to day surgery were found to be at risk for sleep disordered breathing. The median PSQ score for the children at risk was 9.2 for urological surgeries, 10.9 for general surgery, and 11.3 for otolaryngological procedures.

CONCLUSIONS

There is an increased prevalence of children at risk of SRBD awaiting common day surgery procedures than previously expected based on existing literature. Patients undergoing otolaryngological procedures were at greater risk of sleep-related breathing disorders when compared with patients undergoing urological or general surgical procedures. There may be a role for screening of pediatric patients with a PSQ prior to day-surgery.

LEVEL OF EVIDENCE

Type of study: prognosis study, level IV.

The Comparison of Preventive Analgesic Effects of Ketamine, Paracetamol and Magnesium Sulfate on Postoperative Pain Control in Patients Undergoing Lower Limb Surgery: A Randomized Clinical Trial

Background

In considering the importance of postoperative pain management and its consequences on its related secondary outcomes including nausea, vomiting, and operation-related complications, we aimed to compare the effectiveness of the three analgesic agents including ketamine, paracetamol, and magnesium sulfate for postoperative pain relief and associated consequences in this trial.

Materials and Methods

In this double-blinded randomized control clinical trial, patients scheduled for elective lower extremity orthopedic surgery under general anesthesia were enrolled and randomized into four groups for receiving intravenous ketamine (0.25 mg/kg), paracetamol (15 mg/kg), magnesium sulfate (7.5 mg/kg), and placebo (normal saline), immediately after the induction of anesthesia. Postoperative pain scores, analgesic, and metoclopramide use, and frequency of vomiting and satisfaction score of studied patients in the four studied groups during the 6 h, 6-12 h, and 12-24 h after recovery were recorded and compared.

Results

In this trial, thirty patients randomized in each studied groups. Mean of postoperative pain score was significantly lower in ketamine group than others during 24 h after recovery (P < 0.001). Mean of additive analgesic use was significantly lower in ketamine group during 12 h after recovery (P < 0.001), but it was not significantly different during 12-24 h after recovery (P = 0.12). Mean of vomiting frequency and metoclopramide use was not different between groups (P > 0.05). Excellent and good satisfaction score were significantly higher in ketamine group than other groups (P = 0.04).

Conclusions

Ketamine has more superior effect for during recovery and postoperative pain controlling and analgesic use than paracetamol and magnesium sulfate.

Effects of Addition of Preoperative Intravenous Ibuprofen to Pregabalin on Postoperative Pain in Posterior Lumbar Interbody Fusion Surgery

OBJECTIVE

Ibuprofen and pregabalin both have independent positive effects on postoperative pain. The aim of the study is researching effect of 800 mg i.v. ibuprofen in addition to preoperative single dose pregabalin on postoperative analgesia and morphine consumption in posterior lumbar interbody fusion surgery.

MATERIALS AND METHODS

42 adult ASA I-II physical status patients received 150 mg oral pregabalin 1 hour before surgery. Patients received either 250 ml saline with 800 mg i.v. ibuprofen or saline without ibuprofen 30 minutes prior to the surgery. Postoperative analgesia was obtained by morphine patient controlled analgesia (PCA) and 1 g i.v. paracetamol every six hours. PCA morphine consumption was recorded and postoperative pain was evaluated by Visual Analog Scale (VAS) in postoperative recovery room, at the 1st, 2nd, 4th, 8th, 12th, 24th, 36th, and 48th hours.

RESULTS

Postoperative pain was significantly lower in ibuprofen group in recovery room, at the 1st, 2nd, 36th, and 48th hours. Total morphine consumption was lower in ibuprofen group at the 2nd, 4th, 8th, 12th, and 48th hours.

CONCLUSIONS

Multimodal analgesia with preoperative ibuprofen added to preoperative pregabalin safely decreases postoperative pain and total morphine consumption in patients having posterior lumbar interbody fusion surgery, without increasing incidences of bleeding or other side effects.

Trends in Perioperative Practice and Resource Utilization in Patients With Obstructive Sleep Apnea Undergoing Joint Arthroplasty

BACKGROUND

Emerging evidence associating obstructive sleep apnea (OSA) with adverse perioperative outcomes has recently heightened the level of awareness among perioperative physicians. In particular, estimates projecting the high prevalence of this condition in the surgical population highlight the necessity of the development and adherence to "best clinical practices." In this context, a number of expert panels have generated recommendations in an effort to provide guidance for perioperative decision-making. However, given the paucity of insights into the status of the implementation of recommended practices on a national level, we sought to investigate current utilization, trends, and the penetration of OSA care-related interventions in the perioperative management of patients undergoing lower joint arthroplasties.

METHODS

In this population-based analysis, we identified 1,107,438 (Premier Perspective database; 2006-2013) cases of total hip and knee arthroplasties and investigated utilization and temporal trends in the perioperative use of regional anesthetic techniques, blood oxygen saturation monitoring (oximetry), supplemental oxygen administration, positive airway pressure therapy, advanced monitoring environments, and opioid prescription among patients with and without OSA.

RESULTS

The utilization of regional anesthetic techniques did not differ by OSA status and overall <25% and 15% received neuraxial anesthesia and peripheral nerve blocks, respectively. Trend analysis showed a significant increase in peripheral nerve block use by >50% and a concurrent decrease in opioid prescription. Interestingly, while the absolute number of patients with OSA receiving perioperative oximetry, supplemental oxygen, and positive airway pressure therapy significantly increased over time, the proportional use significantly decreased by approximately 28%, 36%, and 14%, respectively. A shift from utilization of intensive care to telemetry and stepdown units was seen.

CONCLUSIONS

On a population-based level, the implementation of OSA-targeted interventions seems to be limited with some of the current trends virtually in contrast to practice guidelines. Reasons for these findings need to be further elucidated, but observations of a dramatic increase in absolute utilization with a proportional decrease may suggest possible resource constraints as a contributor.

Prevention of chronic post-surgical pain: the importance of early identification of risk factors

Chronic post-surgical pain (CPSP) is currently an inevitable surgical complication. Despite the advances in surgical techniques and the development of new modalities for pain management, CPSP can affect 15-60% of all surgical patients. The development of chronic pain represents a burden to both the patient and to the community. In order to have a meaningful impact on this debilitating condition it is essential to identify those at risk. Early identification of patients at risk will help to reduce the percentage of patients who go on to develop CPSP. Unfortunately, evidence about any effective actions to reduce this condition is limited. This review will focus on providing context to the challenging problem of CPSP. The possible role of both the surgeon and anesthesiologist in reducing the incidence of this problem will be explored.

Hepatic resection is associated with reduced postoperative opioid requirement

Background and Aims:

Postoperative pain can significantly affect surgical outcomes. As opioid metabolism is liver-dependent, any reduction in hepatic volume can lead to increased opioid concentrations in the blood. The hypothesis of this retrospective study was that patients undergoing open hepatic resection would require less opioid for pain management than those undergoing open pancreaticoduodenectomy.

Material and Methods:

Data from 79 adult patients who underwent open liver resection and eighty patients who underwent open pancreaticoduodenectomy at our medical center between January 01, 2010 and June 30, 2013 were analyzed. All patients received both general and neuraxial anesthesia. Postoperatively, patients were managed with a combination of epidural and patient-controlled analgesia. Pain scores and amount of opioids administered (morphine equivalents) were compared. A multivariate lineal regression was performed to determine predictors of opioid requirement.

Results:

No significant differences in pain scores were found at any time point between groups. Significantly more opioid was administered to patients having pancreaticoduodenectomy than those having a hepatic resection at time points: Intraoperative (P = 0.006), first 48 h postoperatively (P = 0.001), and the entire length of stay (LOS) (P = 0.002). Statistical significance was confirmed after controlling for age, sex, body mass index, and American Society of Anesthesiologists physical status classification (adjusted P = 0.006). Total hospital LOS was significantly longer after pancreaticoduodenectomy (P = 0.03). A multivariate lineal regression demonstrated a lower opioid consumption in the hepatic resection group (P = 0.03), but there was no difference in opioid use based on the type of hepatic resection.

Conclusion:

Patients undergoing open hepatic resection had a significantly lower opioid requirement in comparison with patients undergoing open pancreaticoduodenectomy. A multicenter prospective evaluation should be performed to confirm these findings.

Perspectives on Intravenous Oxycodone for Control of Postoperative Pain

Intravenous (IV) analgesia has particular advantages in the immediate postoperative period. For example, IV administration results in a faster onset of pain relief and results in more predictable pharmacokinetics than does administration by other routes. It also allows for convenient dosing before or during surgery, permitting the initiation of effective analgesia in the early phase of the postoperative period. In addition, when patients are able to tolerate oral intake, they can be switched from IV to oral dosing based on maintaining the predictable analgesia established by the IV route. IV morphine is widely used for the control of postoperative pain, but there is a trend toward the use of oxycodone. Oxycodone (which may be mediated partly through kappa- as well as mu-opioid receptors) offers several potential advantages. Published studies comparing IV oxycodone to other IV opioids for postsurgical pain report that oxycodone is a safe and effective analgesic. Some studies show that IV oxycodone may be associated with greater pain control, fewer or less severe adverse events, and faster onset of action, although the results are not consistent across all studies. Oxycodone has been reported to be safe in the geriatric and other special populations when adequate clinical adjustments are made. Thus, the clinical reports and oxycodone's pharmacologic profile make intravenous oxycodone a potentially important "new" old drug for postoperative pain control.

The effect of using an abdominal binder on postoperative gastrointestinal function, mobilization, pulmonary function, and pain in patients undergoing major abdominal surgery: A randomized controlled trial

BACKGROUND

Evidence on the effectiveness of using a binder following abdominal surgery and its effect on gastrointestinal function, mobilization, pulmonary function, and pain is currently unclear.

OBJECTIVE

The purpose of this study is to determine the effect of abdominal binder usage on gastrointestinal function, mobilization, pulmonary function, and postoperative pain in patients undergoing major abdominal surgery.

DESIGN

This research was conducted as a randomized controlled trial.

SETTINGS

The study was conducted at the Department of General Surgery at a military education and research hospital in Ankara, Turkey, between September 2013 and April 2014.

PARTICIPANTS

104 patients were assessed for eligibility. The study was conducted on 84 eligible patients.

METHODS

The study sample consisted of 84 patients who underwent effective major abdominal surgery. The patients were randomized into two groups, the intervention group, which used an abdominal binder and the control group, which did not. Gastrointestinal function, mobilization, pulmonary function, and the pain status of both groups were evaluated on the first, fourth, and seventh days before and after surgery, and the intergroup results were compared.

RESULTS

No significant difference was found between the two groups in terms of gastrointestinal and pulmonary function on the first, fourth, and seventh days following surgery (p>0.05). A comparative assessment of mobility by walking distance showed that patients in the intervention group were able to walk further on the fourth [mean (SD); 221.19 (69.08) m] and seventh [227.85 (60.02) m] days after surgery (p=0.003, p<0.001). There were differences in the acute pain status between patients in both groups (p<0.05). On the first [mean (SD); 8.80 (5.03)], fourth [4.83 (2.78)], and seventh [3.09 (3.17)] days after surgery, the sensory sub-scale pain scores were higher in the control group (p<0.001). On the first [mean (SD); 10.16 (6.14)], fourth [5.28 (3.52)], and seventh [3.30 (3.51)] days after surgery the total pain scores were higher in the control group (p<0.001). The visual analogue scale scores were also higher in the control group on the first [mean (SD) 6.26 (1.86)], fourth [4.50 (2.10)], and seventh [3.04 (2.43)] days after surgery (p<0.001).

CONCLUSION

The study's findings reveal that the use of an abdominal binder does not have any effect on postoperative gastrointestinal and pulmonary function. However, an abdominal binder increases patient mobility soon after surgery. There was also a measurable effect on pain, with lower scores reported by patients who used an abdominal binder after any exercise or activity. These results indicate that the use of a routine abdominal binder is helpful for patients undergoing major abdominal surgery.

Low-Dose Ketamine Infusions for Highly Opioid-Tolerant Adults Following Spinal Surgery: A Retrospective Before-and-after Study

Managing acute-on-chronic pain in opioid-tolerant individuals is complex and challenging; exploring new analgesia regimens for this population is essential. Ketamine is an N-methyl D-aspartate antagonist that blocks transmission of painful stimuli and could be a useful medication for this patient population. A new low-dose ketamine protocol as an adjunct to conventional pain therapy was implemented in a major urban Level 1 trauma center in Canada. A retrospective before-and-after chart review was conducted to explore the research question, "What is the effect of low-dose ketamine continuous intravenous infusions on pain of highly opioid-tolerant adults following spinal surgery?". All patients had spine surgery, used a minimum of 100 mg daily oral morphine equivalent preoperatively and were followed postoperatively by the hospital's Acute Pain Service. Data from individuals treated with conventional therapy during the year prior to protocol implementation were compared with data from patients who received conventional therapy plus ketamine post implementation. Outcome measures included pain scores and daily opioid consumption on postoperative days 0 through 5, time to ambulation, time to discharge, and adverse effects. There were no statistically significant differences between conventional therapy and conventional therapy plus ketamine. Ketamine may still be of benefit to patients with acute-on-chronic pain, although this was not evident in this study. Future research using more robust assessment tools to determine effectiveness of ketamine is required.

An Audit of Changes in Outcomes of Acute Pain Service: Evolution Over the Last 2 Decades

Acute pain services (APS) have evolved over time. Strategies nowadays emphasize multimodal analgesic regimes using a combination of nonopioid adjuvant analgesic drugs, peripheral nerve blocks, and local anaesthetic wound infiltration where appropriate. APS should be assessed over time to evaluate changes in outcomes which form the basis for future development. In this audit, data of patients under APS care in Queen Mary hospital, Hong Kong, between 2009 and 2012 were analyzed and compared with data from a previous audit between 1992 and 1995. The use of patient-controlled analgesia (PCA) was increased (from 69.3% to 86.5%, P < 0.001), while the use of epidural analgesia reduced (from 25.3% to 8.3%, P < 0.001) significantly. Although postoperative pain scores did not improve, PCA opioid consumption and the incidence of analgesia-related side effects were significantly less (all P < 0.001). More patients graded their postoperative analgesic techniques used as good when the results from these 2 audit periods were compared (P < 0.001 and P = 0.001 for PCA and epidural analgesia, respectively). In conclusion, there has been a change in analgesic management techniques, but there has been no improvement in overall pain relief. While changes over time have led to improvement in important parameters such as the incidence of side effects and patient satisfaction, further and continuous efforts and improvements are warrant to reduce acute pain relief and suffering of the patients after the surgery.

Assessment of rescue opioid use in patients with post-bunionectomy pain treated with diclofenac potassium liquid-filled capsules

When used in multimodal analgesia for acute pain, nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the requirement for opioids during the perioperative period. To provide more insight into pain treatment during the outpatient period, we examined the use of opioid rescue medication (RM) and described the relationship between pain intensity and RM use in patients with acute pain after bunionectomy. Patients received placebo or 25 mg of a liquid-filled capsule version of the NSAID diclofenac potassium (DPLFC; n=188 patients/group) every 6 hours during the 48-hour inpatient period through the end of outpatient dosing on day 4. Opioid RM (hydrocodone/acetaminophen tablets, 5 mg/500 mg) was available as needed, but taken at least 1 hour post-study medication. Fewer patients taking DPLFC versus placebo requested opioid RM during the inpatient period (4.8%-44.7% versus 25.0%-90.4%) and also during the outpatient period (3.7%-16.0% versus 13.1%-46.4%). Moderate or severe pain after surgery (P=0.0307 and P=0.0002, respectively) or at second dose (P=0.0006 and P=0.0002, respectively) was predictive of RM use. Patients taking RM (placebo/DPLFC) reported more adverse events (RM 55.7%/40.6%; no RM 29.4%/26.0%). Most adverse events in the RM group were opioid-related. In summary, this study shows that DPLFC lowers the requirement for opioids, which is associated with a reduction in the occurrence of treatment side effects, while maintaining adequate analgesia for patients with moderate acute pain in both the outpatient and outpatient periods. Patients with more severe pain are more likely to use RM, but they still use fewer opioids when treated with DPLFC. This suggests that multimodal treatment using DPLFC and an opioid may offer an important clinical benefit in the treatment of acute pain, including in the home environment.

Intravenous non-opioid analgesia for peri- and postoperative pain management: a scientific review of intravenous acetaminophen and ibuprofen

Pain is a predictable consequence following operations, but the management of postoperative pain is another challenge for anesthesiologists and inappropriately controlled pain may lead to unwanted outcomes in the postoperative period. Opioids are indeed still at the mainstream of postoperative pain control, but solely using only opioids for postoperative pain management may be connected with risks of complications and adverse effects. As a consequence, the concept of multimodal analgesia has been proposed and is recommended whenever possible. Acetaminophen is one of the most commonly used analgesic and antipyretic drug for its good tolerance and high safety profiles. The introduction of intravenous form of acetaminophen has led to a wider flexibility of its use during peri- and postoperative periods, allowing the early initiation of multimodal analgesia. Many studies have revealed the efficacy, safety and opioid sparing effects of intravenous acetaminophen. Intravenous ibuprofen has also shown to be well tolerated and demonstrated to have significant opioid sparing effects during the postoperative period. However, the number of randomized controlled trials confirming the efficacy and safety is small and should be used in caution in certain group of patients. Intravenous acetaminophen and ibuprofen are important options for multimodal postoperative analgesia, improving pain and patient satisfaction.

A review of the literature on multiple factors involved in postoperative pain course and duration

OBJECTIVE

To review the literature on the progression from acute to chronic postoperative pain, to evaluate the evidence for the risk of progressing to persistent postoperative and chronic pain, and to identify characteristics of pharmacologic treatments to best tailor therapy to an individual patient's pain profile.

BACKGROUND

Pain is most commonly classified by duration (acute, chronic) and pathophysiology (nociceptive, neuropathic); however, these descriptors alone incompletely describe pain. Additionally, the transition between acute and chronic postoperative pain is not well understood.

METHODS

We conducted a qualitative review and evaluation of the literature on postoperative pain with respect to the above objectives.

RESULTS

Individualized pharmacologic treatments require a complete characterization of a patient's pain profile, in terms of frequency of pain over the course of a 24-hour day and over time thereafter, frequency and duration of pain flares, and presence of neuropathic pain. These considerations can help guide the choice of pharmacologic treatment to meet patient needs over a 24-hour day and over time after surgery. With respect to opioid analgesics, acute pain requires rapid onset of analgesia and the ability to titrate analgesia to the changing characteristics of pain over a short period. For these reasons, short-acting opioid analgesics have been preferred; however, there are opioid formulations with rapid onset and extended release for reduced dosing frequency. Although nociceptive pain can typically be controlled by titration of the dose of an opioid analgesic, neuropathic pain may respond better to the addition of an antineuropathic medication rather than to opioid dose escalation.

CONCLUSION

Advances in individualized pharmacologic treatment for postoperative pain have resulted in better pain control. Moreover, the recognition of sub-acute pain as a new entity is important because many surgical patients will need therapy beyond the first 8 days after surgery. In this group of patients the diagnosis of a neuropathic pain component will be important so that appropriate multimodal therapy may be implemented.

The role of a low-dose ketamine-midazolam regimen in the management of severe painful crisis in patients with sickle cell disease

CONTEXT

Acute pain is one of the main causes of hospital admission in sickle cell disease, with variable intensity and unpredictable onset and duration.

OBJECTIVES

We studied the role of a low-dose intravenous (IV) ketamine-midazolam combination in the management of severe painful sickle cell crisis.

METHODS

A retrospective analysis was performed with data from nine adult patients who were admitted to the intensive care unit with severe painful sickle cell crises not responding to high doses of IV morphine and other adjuvant analgesics. A ketamine-midazolam regimen was added to the ongoing opioids as an initial bolus of ketamine 0.25mg/kg, followed by infusion of 0.2-0.25mg/kg/h. A midazolam bolus of 1mg followed by infusion of 0.5-1mg/h was added to reduce ketamine emergence reactions. Reduction in morphine daily requirements and improvement in pain scores were the determinants of ketamine-midazolam effect. The t-tests were used for statistical analysis.

RESULTS

Nine patients were assessed, with mean age of 27±11 years. Morphine requirement was significantly lower after adding the IV ketamine-midazolam regimen. The mean±SD IV morphine requirement (milligram/day) in the pre-ketamine day (D0) was 145.6±16.5, and it was 112±12.2 on Day 1 (D1) of ketamine treatment (P=0.007). The Numeric Rating Scale scores on D0 ranged from eight to ten (mean 9.1), but improved to range from five to seven (mean 5.7) on D1. There was a significant improvement in pain scores after adding ketamine-midazolam regimen (P=0.01).

CONCLUSION

Low-dose ketamine-midazolam IV infusion might be effective in reducing pain and opioid requirements in patients with sickle cell disease with severe painful crisis. Further controlled studies are required to prove this effect.

Of rough starts and smooth finishes: correlations between post-anesthesia care unit and postoperative days 1-5 pain scores

OBJECTIVE

The goal of this project was to explore the association between post-anesthesia care unit (PACU) pain scores recorded within the first and second hour of the end of surgery with maximum and median pain scores recorded on postoperative days (PODs) 1 through 5.

DESIGN

This study was a retrospective cohort study of clinically documented pain scores in a mixed surgical population.

SETTING

This study was set in a single tertiary-care teaching hospital over a 1-year time period.

PATIENTS

All patients were adult patients undergoing a single, non-ambulatory, non-obstetric surgical procedure.

MEASURES

Pain scores, measured using the numerical rating scale, from PODs 0 through 5 were obtained from an integrated data repository. Kendall's Tau-b correlations were then calculated between maximum pain scores occurring within each of the two PACU time periods and maximum and median pain scores in each of the five ensuing PODs.

RESULTS

A total of 349,797 pain scores from 8,332 patients were reviewed. Correlations between maximum pain score by time period demonstrated a significant and high correlation at Tau-b = 0.86, between 1-hour PACU pain scores and 2-hour PACU pain scores. However, the correlation of maximum pain scores recorded in the PACU with those recorded on PODs 1 through 5 was significantly lower, ranging from 0.19 to 0.27. The correlation of maximum PACU pain score with median pain scores recorded on PODs 1 through 5 ranged from 0.22 to 0.29. The correlation structures of the PODs 1 through 5 median pain scores may be consistent with an autoregressive pattern.

CONCLUSIONS

Maximum scores measured within the PACU likely reflect a set of circumstances distinct from those experienced on PODs 1 through 5.

Femoral nerve block: Assessment of postoperative analgesia in arthroscopic anterior cruciate ligament reconstruction

BACKGROUND AND OBJECTIVES

Knee anterior cruciate ligament reconstruction (ACLR) may be painful in the postoperative period. The primary objective of this study was to evaluate whether the use of femoral nerve block (FNB) associated with spinal anesthesia would improve the postoperative pain treatment in ACLR and the secondary objectives were to evaluate tramadol request and adverse events.

METHOD

53 patients were randomly divided into two groups: GA (n =26) received spinal anesthesia and GB (n = 27) received spinal anesthesia and FNB. All patients received multimodal analgesia and rescue analgesics could be requested anytime. Assessments were performed at 6, 12 and 24 hours.

RESULTS

There was no difference between both groups regarding demographic and clinical- surgical variables. There was no difference between groups regarding pain intensity. Mean pain scores were higher at 12 hours in GA and there was no change in GB; 55.6% of patients reported moderate pain in GA and 53.8% mild pain in GB. There was no difference regarding tramadol request. There were no serious adverse events: 80.8% of patients in GB had motor block of the thigh and two fell.

CONCLUSIONS

Analgesia was more effective with the combination of spinal and FNB, which allowed better control of postoperative pain, assessed 12 hours after anesthesia. There was no difference in tramadol request. Patients in this study had no serious adverse events; however, one must be attentive to motor paralysis and the possibility of falling when FNB is performed.

Recent management advances in acute postoperative pain

INTRODUCTION

Acute postoperative pain remains a major problem, with both undertreatment and overtreatment leading to serious consequences, including increased risk of persistent postoperative pain, impaired rehabilitation, increased length of stay and/or hospital readmission, and adverse events related to excessive analgesic use, such as oversedation. New analgesic medications and techniques have been introduced that target the preoperative, intraoperative, and postoperative periods to better manage acute postoperative pain, with improvements in analgesic efficacy and safety over more traditional pain management approaches. This review provides an overview of these new analgesic medications and techniques. Specific topics that are discussed include the use of preoperative nonsteroidal anti-inflammatory drugs, anxiolytics, and anticonvulsants; intraoperative approaches such as neuraxial analgesia, continuous local anesthetic wound infusion, transversus abdominis plane block, extended-release epidural morphine, intravenous acetaminophen, and intravenous ketamine; and postoperative use of intravenous ibuprofen, new opioids (eg, tapentadol) or opioid formulations (morphine-oxycodone), and patient-controlled analgesia.

CONCLUSION

New, targeted, analgesic medications and techniques may provide a safer and more effective approach to the management of acute postoperative pain than traditional approaches such as postoperative oral analgesics.