Administration of fentanyl before remifentanil-based anaesthesia has no influence on post-operative pain or analgesic consumption

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 In addition, we searched for unpublished studies in three clinical trial databases, conference proceedings, grey literature databases, and reference lists of retrieved articles.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.

Anesthesia for ambulatory surgery

Ambulatory anesthesia allows quick recovery from anesthesia, leading to an early discharge and rapid resumption of daily activities, which can be of great benefit to patients, healthcare providers, third-party payers, and hospitals. Recently, with the development of minimally invasive surgical techniques and short-acting anesthetics, the use of ambulatory surgery has grown rapidly. Additionally, as the indications for ambulatory surgery have widened, the surgical methods have become more complex and the number of comorbidities has increased. For successful and safe ambulatory anesthesia, the anesthesiologist must consider various factors relating to the patient. Among them, appropriate selection of patients and surgical and anesthetic methods, as well as postoperative management, should be considered simultaneously. Patient selection is a particularly important factor. Appropriate surgical and anesthetic techniques should be used to minimize postoperative complications, especially postoperative pain, nausea, and vomiting. Patients and their caregivers should be fully informed of specific care guidelines and appropriate responses to emergency situations on discharge from the hospital. During this process, close communication between patients and medical staff, as well as postoperative follow-up appointments, should be ensured. In summary, safe and convenient methods to ensure the patient's return to function and recovery are necessary.

Pain Management After Outpatient Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Effective pain management after anterior cruciate ligament (ACL) reconstruction improves patient satisfaction and function.

PURPOSE

To collect and evaluate the available evidence from randomized controlled trials (RCTs) on pain control after ACL reconstruction.

STUDY DESIGN

Systematic review.

METHODS

A systematic literature review was performed using PubMed, Medline, Google Scholar, UpToDate, Cochrane Reviews, CINAHL, and Scopus following PRISMA guidelines (July 2014). Only RCTs comparing a method of postoperative pain control to another method or placebo were included.

RESULTS

A total of 77 RCTs met inclusion criteria: 14 on regional nerve blocks, 21 on intra-articular injections, 4 on intramuscular/intravenous injections, 12 on multimodal regimens, 6 on oral medications, 10 on cryotherapy/compression, 6 on mobilization, and 5 on intraoperative techniques. Single-injection femoral nerve blocks provided superior analgesia to placebo for up to 24 hours postoperatively; however, this also resulted in a quadriceps motor deficit. Indwelling femoral catheters utilized for 2 days postoperatively provided superior analgesia to a single-injection femoral nerve block. Local anesthetic injections at the surgical wound site or intra-articularly provided equivalent analgesia to regional nerve blocks. Continuous-infusion catheters of a local anesthetic provided adequate pain relief but have been shown to cause chondrolysis. Cryotherapy improved analgesia compared to no cryotherapy in 4 trials, while in 4 trials, ice water and water at room temperature provided equivalent analgesic effects. Early weightbearing decreased pain compared to delayed weightbearing. Oral gabapentin given preoperatively and oral zolpidem given for the first week postoperatively each decreased opioid consumption as compared to placebo. Ibuprofen reduced pain compared to acetaminophen. Oral ketorolac reduced pain compared to hydrocodone-acetaminophen.

CONCLUSION

Regional nerve blocks and intra-articular injections are both effective forms of analgesia. Cryotherapy-compression appears to be beneficial, provided that intra-articular temperatures are sufficiently decreased. Early mobilization reduces pain symptoms. Gabapentin, zolpidem, ketorolac, and ibuprofen decrease opioid consumption. Despite the vast amount of high-quality evidence on this topic, further research is needed to determine the optimal multimodal approach that can maximize recovery while minimizing pain and opioid consumption.

CLINICAL RELEVANCE

These results provide the best available evidence from RCTs on pain control regimens after ACL reconstruction.

Does small-dose fentanyl improve perioperative outcomes in the ambulatory setting? A randomized, double-blind, placebo-controlled study

BACKGROUND

Despite its widespread use, the beneficial effect of low-dose fentanyl administered at induction of anesthesia on perioperative outcomes has not been studied in the ambulatory setting. Therefore, this study was designed to test the hypothesis that administration of small-dose fentanyl vs. saline during induction reduces coughing and movements without adversely affecting recovery after day-surgery.

METHODS

One hundred consenting outpatients scheduled to undergo superficial surgical procedures under general anesthesia with a laryngeal mask airway (LMA) device for airway management were randomly assigned to one of two treatment groups: control (n = 50) or fentanyl (n = 50). After administration of 2 ml of the unlabelled study medication containing either fentanyl (100 μg) or saline, anesthesia was induced with lidocaine 30-50 mg and propofol 2 mg/kg IV followed by the insertion of an LMA device. General anesthesia was maintained using a propofol infusion, 75 μg/kg/min, and desflurane (2-5% end-tidal) in 100% oxygen.

RESULTS

Coughing was observed in six (12%) and ten (20%) in the fentanyl and control group, respectively (P = 0.41). The incidence of movements during surgery was lower in the fentanyl group (18% vs. 31%, P < 0001). There were no significant differences in early and late recovery times or pain scores between the two groups.

CONCLUSION

Administration of a small-dose of fentanyl at induction of anesthesia significantly reduced purposeful movements during day-surgery under propofol-desflurane anesthesia. No significant difference was found in coughing or recovery times.

A comparison of oxycodone prolonged-release vs. oxycodone + naloxone prolonged-release after laparoscopic hysterectomy

BACKGROUND

Targiniq®, an oxycodone prolonged-release (PR) formulation combined with the opioid antagonist naloxone PR, aims to prevent opioid-induced constipation without impairing the analgesic efficacy. This has been confirmed during prolonged use in chronic pain or cancer patients. The purpose of our study was to compare clinical effects of oxycodone PR with oxycodone PR + naloxone PR for short-term post-operative pain management.

METHODS

This randomised, double-blind, prospective study included 85 women undergoing laparoscopic hysterectomy. The two groups received either oxycodone PR 10 mg or oxycodone PR 10 mg + naloxone PR 5 mg as pre-medication and twice daily for 3 days. As rescue analgesic, the patients received oxycodone intravenous during the first 24 h post-operatively and oxycodone tablets in the 24-72-h period. Constipation, other side effects, pain and satisfaction were registered during the first 7 post-operative days.

RESULTS

Demographic, pre- and perioperative variables and the use of rescue analgesics were similar in the groups. There were no significant differences in variables related to constipation. In the oxycodone PR + naloxone PR group, 25% had no defecation during the first 72 h post-operatively, compared with 20% in the oxycodone PR group (mean 1.2 ± 1.1 vs. 2.1 ± 2.4 defecations). Other opioid-induced effects and side effects showed no significant differences. Only 7% were dissatisfied with their oral pain treatment.

CONCLUSION

Addition of naloxone to oxycodone PR tablets in a pain regimen administered twice daily the first three post-operative days had no significant clinical effects on constipation or other variables during the first week after hysterectomy.

Effect of timing of morphine administration during propofol - remifentanil anesthesia on the requirements of post-operative analgesia

Background

An important concern of intra-operative infusion of remifentanil is the possible development of acute opioid tolerance, which manifests as an increased postoperative analgesia requirement. We have examined the effect of the timing of intra operative morphine administration on the need for morphine consumption for pain control during the first 24 hours after operation.

Methods

Sixty adult patients scheduled for elective open unilateral nephrolithotomy surgery were recruited for this prospective randomized double-blind study. Anesthesia was induced with 0.03 mg/kg midazolam, 1 µg/kg remifentanil, and 1.5-2 mg/kg propofol. Anesthesia was maintained with 100 µg/kg/min propofol, and 0.25 µg/kg/min remifentanil. Both groups received 0.1 mg/kg morphine intravenously at 2 different times; in the first group (group E) immediately after intubation and in the second group (group L) 20-30 min before the anticipated end of operation.

Results

There was no difference in pain scores at awakening, the amount of morphine given to the 2 groups for pain control, or the time to discharge from PACU between the 2 groups. The pain scores at admission to ward and at every 4 hours thereafter, until 24 hours, were not significantly different between the 2 groups. The cumulative amount of the first 24 hours morphine consumption in the ward in E group was 28.2 ± 20.1 mg and 26.5 ± 15 mg in L group, respectively (P = 0.71).

Conclusions

Early intra-operative administration of morphine compared to that of morphine in the end of surgery did not affect postoperative morphine consumption and pain scores during the first 24 hours after surgery for open nephrolithotomy. Newer pharmacologic interventions for prevention of acute tolerance of opioids seems rational (Clinical trial registration No. ACTRN: 12609000570280).

Short stay and less pain after ambulatory anterior cruciate ligament (ACL) repair: COX-2 inhibitor versus glucocorticoid versus both combined

BACKGROUND

Many studies have demonstrated that either COX-2 antagonists or glucocorticoids are efficient analgesics after orthopaedic surgery. We wanted to evaluate if the combination of these two drugs was better than one drug alone when added to paracetamol, local anaesthesia, and cryo-cuff for outpatient anterior crucial ligament (ACL) surgery.

METHODS

In a double-blind design, 89 adult patients scheduled for day-case ACL repair in general anaesthesia were randomly assigned into three groups: The COXIB group (n = 30) received either 40 mg parecoxib iv or 120 mg etoricoxib orally 1 h before surgery. The STEROID group (n = 30) received 8 mg dexamethasone iv, and the combination group (Group COMBI, n = 29) received both.

RESULTS

At 24 h, Group COMBI had significantly lower visual analogue scale (0-10 cm) scores during rest (2.1 ± 1.3) (mean ± standard deviation) and movement (4.2 ± 2.5) when compared to both the COXIB group (P = 0.04) and the STEROID group (P = 0.035). The accumulated consumption of rescue opioids (5.2 ± 4,5 mg morphine) was also significantly lower at 24 h compared to the other groups (P = 0.02). Mean time to discharge from hospital was about 3 h in all groups. The pain scores in the post-anaesthetic care unit, mobilization at 24 h and 7 days, and general level of satisfaction were similar between the groups.

CONCLUSION

The combination of a COX-2 inhibitor and dexamethasone results in better pain relief 24 h after surgery in patients undergoing outpatient ACL surgery, compared to COX-2 inhibitor alone or dexamethasone alone. With a dedicated multimodal pain regime, most ACL patients may be discharged within 3 h.

Long-term potentiation in spinal nociceptive pathways as a novel target for pain therapy

Long-term potentiation (LTP) in nociceptive spinal pathways shares several features with hyperalgesia and has been proposed to be a cellular mechanism of pain amplification in acute and chronic pain states. Spinal LTP is typically induced by noxious input and has therefore been hypothesized to contribute to acute postoperative pain and to forms of chronic pain that develop from an initial painful event, peripheral inflammation or neuropathy. Under this assumption, preventing LTP induction may help to prevent the development of exaggerated postoperative pain and reversing established LTP may help to treat patients who have an LTP component to their chronic pain. Spinal LTP is also induced by abrupt opioid withdrawal, making it a possible mechanism of some forms of opioid-induced hyperalgesia. Here, we give an overview of targets for preventing LTP induction and modifying established LTP as identified in animal studies. We discuss which of the various symptoms of human experimental and clinical pain may be manifestations of spinal LTP, review the pharmacology of these possible human LTP manifestations and compare it to the pharmacology of spinal LTP in rodents.

Acute and chronic pain following craniotomy

PURPOSE OF REVIEW

The purpose of the review is to describe what is currently known about the mechanisms, incidence and risk factors for acute and chronic postcraniotomy pain. The review will also summarize the evidence supporting the prevention and management of acute and chronic postcraniotomy pain.

RECENT FINDINGS

Current studies suggest acute and chronic pain is common in patients after craniotomy. Surgical and patient factors may influence the incidence and severity of pain and a multimodal approach to acute postcraniotomy pain is recommended. Although codeine and tramadol are frequently used in the postoperative period, research suggests morphine provides superior efficacy with a good safety profile. Local anesthesia with nerve blocks has not been shown to consistently reduce acute postoperative pain, though it has recently been demonstrated to dramatically reduce the incidence of chronic pain. Despite this, little is known about the mechanisms, prevention and treatment of chronic postcraniotomy pain.

SUMMARY

Acute and chronic pain following craniotomy is frequent and underrecognized. Several surgical and patient risk factors predispose patients to pain following neurosurgery. Further research is needed to determine the mechanisms, predictors, prevention and optimal treatment of acute and chronic pain following craniotomy.