Herniorraphy 2004

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Oral rofecoxib administered pre- plus postoperatively significantly reduced postoperative pain scores, compared with placebo, at rest at 1 h (p<0.05) but there was no benefit at 30 min or at the time of first analgesic request (n=60) Ma et al 2004
• Oral rofecoxib administered pre- plus postoperatively significantly reduced requirements for supplementary hydromorphone in the PACU (p<0.05) (n=60) Ma et al 2004

Arguments against…

• Oral rofecoxib administered pre- plus postoperatively did not significantly reduce the incidence of PONV compared with placebo (n=60) Ma et al 2004

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• COX-2-selective inhibitors provide similar postoperative analgesia to conventional NSAIDs Rømsing et al 2004
• Randomised endoscopic trials in healthy volunteers have shown that COX-2-selective inhibitors are associated with a lower incidence of upper gastrointestinal ulceration compared with conventional NSAIDs for short-term use Harris et al 2001
• Studies in healthy volunteers demonstrated that COX-2-selective inhibitors had no effect on platelet aggregation Greenberg et al 2000
• Clinical studies investigating the response to oral challenge with COX-2-selective inhibitors in patients with aspirin-induced asthma have demonstrated that COX-2-selective inhibitors do not have an effect on respiratory function Bavbek et al 2004
• A study to assess the safety of the COX-2-selective inhibitors parecoxib and valdecoxib following noncardiac general surgery (including gastrointestinal, orthopaedic, gynaecological, urological, and thoracic surgeries) showed no difference in the incidence of cardiovascular thromboembolic events, renal dysfunction/failure, gastrointestinal ulcer complications, and surgical wound-healing complications, compared with placebo (n=1062) (in press, Anesthesiology)

Arguments against…

• Two clinical trials showed that in patients who had undergone CABG surgery, COX-2-selective inhibitors (valdecoxib and parecoxib) were associated with a higher rate of serious cardiovascular thromboembolic events (including myocardial infarction) compared with placebo Nussmeier et al 2005
• Hypersensitivity reactions and serious skin reactions (e.g. toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme) can occur with all COX-2-selective inhibitors. Serious skin reactions have been reported in association with valdecoxib at a higher rate than with other COX-2-selective agents EMEA 2004a
• Conventional NSAIDs and COX-2-selective inhibitors have been associated with an increased risk of transient hepatotoxicity. Cases of acute hepatic failure have also been reported. Elderly females, with autoimmune disease, and taking other potentially hepatotoxic drugs, may be most susceptible O’Connor et al 2003
• Short-term use of COX-2-selective inhibitors or conventional NSAIDs can increase the risk of transient renal impairment, especially in patients with existing renal dysfunction, and both types of agent have been associated with cases of acute renal failure in high-risk patients Cheng et al 2004
• COX-2-selective inhibitors and conventional NSAIDs may elevate blood pressure, particularly in hypertensive patients receiving antihypertensive medication Cheng et al 2004
• Although there is some concern that COX-2-selective inhibitors may impair wound healing, evidence from animal and clinical studies is conflicting Blomme et al 2003

CLINICAL PRACTICE

• Rofecoxib has been withdrawn from the market, and marketing of valdecoxib has been suspended in most countries

PROSPECT RECOMMENDATIONS

• Postoperative COX-2-selective inhibitors are recommended based on their analgesic efficacy (grade A)
• Since pre-/intra-operative local anaesthetic infiltration techniques provide sufficient analgesia in the immediate postoperative period (grade A), COX-2-selective inhibitors can be initiated orally in the early (1-3 hours) postoperative period
• COX-2-selective inhibitors may be preferred to conventional NSAIDs in the peri-operative setting, in patients who have an increased risk of bleeding, or who are at risk of gastroduodenal ulcer/erosion (grade B)
• The use of COX-2-selective inhibitors should depend upon assessment of individual patient risks (cardiovascular morbidity, actual or recent gastroduodenal ulcer history, renal function and hepatic function [grade B] or aspirin-sensitive asthma [grade D])

HERNIORRAPHY-SPECIFIC EVIDENCE

Arguments for…

• Lysine acetyl salicylate and morphine were similar for verbal rating pain scores at 0, 0.5, 3, 6, 21 and 27 h, and for the proportion of patients requiring supplementary analgesia, but lysine acetyl salicylate was superior to morphine for reducing the incidence of nausea (p<0.05) (n=30) Cashman et al 1985
• Lysine clonixinate and paracetamol/codeine were similar for VAS pain scores at rest or on coughing, sitting or applied pressure during the first 2 days, and for supplementary analgesic requirements (n=151) de los Santos et al 1998

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• Conventional NSAIDs have proven analgesic efficacy in a variety of surgical procedures Barden et al 2004
• One randomised trial in patients undergoing transurethral prostatectomy showed that diclofenac did not affect total blood loss compared with placebo Bricker et al 1987

Arguments for…

• Randomised endoscopic trials in healthy volunteers have shown that COX-2-selective inhibitors are associated with a lower incidence of upper gastrointestinal ulceration compared with conventional NSAIDs for short-term use Harris et al 2001
• Randomised trials in healthy volunteers showed that conventional NSAIDs (ketorolac, naproxen or diclofenac) reduced the platelet aggregation response compared with placebo; ketorolac and naproxen also prolonged bleeding time compared with placebo Greer et al 1999
• Meta-analyses of randomised, controlled trials showed that peri-operative conventional NSAIDs increased the risk of postoperative bleeding requiring treatment and/or the risk of re-operation for haemostasis after tonsillectomy compared with controls Marret et al 2003
• A randomised trial in healthy volunteers showed that three conventional NSAIDs (diclofenac, ketorolac and ketoprofen) caused a reversible platelet dysfunction (diclofenac, ketorolac and ketoprofen) caused a reversible platelet dysfunction Niemi et al 1997
• A randomised controlled trial showed that three conventional NSAIDs (diclofenac, ketorolac and ketoprofen) were associated with a similar incidence of surgical site bleeding after elective surgery Forrest et al 2002
• Aspirin and conventional NSAIDs can induce asthma attacks in patients with aspirin-exacerbated respiratory disease Stevenson 2004
• Conventional NSAIDs and COX-2-selective inhibitors have been associated with an increased risk of transient hepatotoxicity. Cases of acute hepatic failure have also been reported. Elderly females, with autoimmune disease, and taking other potentially hepatotoxic drugs, may be most susceptible O’Connor et al 2003
• Short-term use of conventional NSAIDs or COX-2-selective inhibitors can increase the risk of transient renal impairment, especially in patients with existing renal dysfunction, and both types of agent have been associated with cases of acute renal failure in high-risk patients Cheng et al 2004
• Conventional NSAIDs and COX-2-selective inhibitors may elevate blood pressure, particularly in hypertensive patients receiving antihypertensive medication Cheng et al 2004

PROSPECT RECOMMENDATIONS

• Postoperative conventional NSAIDs are recommended based on their analgesic efficacy (grade A)
• Since pre-/intra-operative local anaesthetic infiltration techniques provide sufficient analgesia in the immediate postoperative period (grade A), conventional NSAIDs can be initiated orally in the early (1-3 hours) postoperative period
• Conventional NSAIDs are not recommended in patients who have an increased risk of bleeding, or who are at risk of gastroduodenal ulcer/erosion (grade B)
• The use of conventional NSAIDs should depend upon assessment of individual patient risks (bleeding complications, cardiovascular morbidity, actual or recent gastroduodenal ulcer history, aspirin-sensitive asthma, renal function and hepatic function) (grade B)

Opioids, which can be naturally occurring, semisynthetic or synthetic compounds, produce analgesic effects by binding to opioid receptors in the central nervous system. Several different opioid receptors have been identified and, based on their interactions with these receptors, opioids fall into three main categories:
Pure agonists – drugs that bind to and stimulate opioid receptors, and are capable of producing a maximal response
Partial agonists – drugs that stimulate opioid receptors but have a ceiling effect, i.e. produce a submaximal response compared with an agonist
Mixed agonist-antagonists – drugs that are agonists for one opioid receptor but antagonise other opioid receptors.
Opioids are also classified as being ‘strong’ or ‘weak’, depending on the strength of their clinical effect, which has historically been measured against the effect of morphine.
Some opioids and their classifications are listed below:

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Postoperative sustained release morphine followed by dihydrocodeine was superior to dihydrocodeine plus paracetamol for reducing pain scores during days 0–5 (p=0.005, n=50) Fenton-Lee et al 1994

Arguments against…

• Postoperative papaveretum/aspirin provided no significant analgesic benefit over placebo, whether both groups received pre-operative inguinal field block or not (n=200) Nehra et al 1995
• Postoperative papaveretum/aspirin was of no significant benefit over placebo for reducing the incidence of PONV (both groups received rescue opioid) (n=200) Nehra et al 1995
• Sustained release morphine followed by dihydrocodeine was inferior to dihydrocodeine plus paracetamol for reducing postoperative nausea scores (n=50) Fenton-Lee et al 1994

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• Strong opioids are effective for reducing high- and moderate-intensity postoperative pain McQuay et al 1999

Arguments against…

• Strong opioids are associated with adverse effects, including nausea, vomiting, sedation, confusion, paralytic ileus and urinary retention Wheeler et al 2002

CLINICAL PRACTICE

Arguments for…

• Strong opioids are not associated with a ceiling effect, and thus can provide effective analgesia for most types of surgical procedures
• Strong opioids are available in a variety of preparations and routes of administration, enabling choice for onset, duration of action, and mode of delivery

PROSPECT RECOMMENDATIONS

• Strong opioids are not recommended for first-line analgesia, despite evidence that they are effective, because of side-effects that may delay early ambulation (Grade D)
• Strong opioids are recommended as rescue analgesia for severe pain in addition to the use of non-opioid agents (Grade B)

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Postoperative dihydrocodeine plus paracetamol was superior to sustained release morphine followed by dihydrocodeine for reducing postoperative nausea scores (n=50) Fenton-Lee et al 1994

Arguments against…

• Codeine plus paracetamol was of no significant benefit over lysine clonixinate for reducing postoperative VAS pain scores at rest or on coughing, sitting or applied pressure during the first 2 days, or supplementary analgesic requirements (n=151) de los Santos et al 1998
• Dihydrocodeine plus paracetamol was inferior to sustained release morphine for reducing pain scores during days 0–5 (p=0.005, n=50) Fenton-Lee et al 1994

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• The combination of tramadol and paracetamol enhances analgesic efficacy compared with either agent alone McQuay H et al 2003

CLINICAL PRACTICE

Arguments for…

• Tramadol is beneficial when conventional NSAIDs are contraindicated
• The oral solution (drops) is useful as rescue medication when paracetamol/conventional NSAIDs/COX-2-selective inhibitor analgesic regimens are used
• Tramadol is useful in the treatment of postoperative pain of moderate intensity (intravenous and oral administration), providing effective analgesia in the in-patient and ambulatory setting
• Opioid adverse effects, especially nausea and dizziness, limit the usefulness of tramadol, but many of the effects are less than for strong opioids

PROSPECT RECOMMENDATIONS

• Weak opioids are recommended based on their analgesic efficacy (Grade B), when conventional NSAIDs or COX-2-selective inhibitors plus paracetamol are not sufficient or are contraindicated

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Postoperative dihydrocodeine plus paracetamol was superior to sustained release morphine followed by dihydrocodeine for reducing postoperative VAS nausea scores (n=50) Fenton-Lee et al 1994

Arguments against…

• Paracetamol plus codeine was of no significant benefit over lysine clonixinate for reducing postoperative VAS pain scores at rest or on coughing, sitting or applied pressure during the first 2 days, or supplementary analgesic requirements (n=151) de los Santos et al 1998
• Dihydrocodeine plus paracetamol was inferior to sustained release morphine followed by dihydrocodeine for reducing pain scores during days 0–5 (p=0.005, n=50) Fenton-Lee et al 1994

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• Paracetamol is an effective analgesic for the treatment of postoperative pain of moderate intensity Hyllested et al 2002
• Paracetamol combined with weak opioids (codeine, tramadol) is superior to weak opioids alone in a review of dental, gynaecological and orthopaedic surgery McQuay H et al 2003

 PROSPECT RECOMMENDATIONS

• Paracetamol is recommended for routine pain therapy in combination with conventional NSAIDs/COX-2-selective inhibitors or weak opioids based on evidence from other surgical procedures (Grade B)

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• Studies of gabapentin and pregabalin in mastectomy, abdominal surgery, laparoscopic cholecystectomy and spinal surgery showed reductions in postoperative pain and supplementary analgesic requirements for at least 24 h Dahl et al 2004

PROSPECT RECOMMENDATIONS

• Gabapentin/pregabalin cannot be recommended at this time (Grade D) due to the lack of procedure-specific evidence, despite analgesic efficacy in other procedures

TRANSFERABLE EVIDENCE FROM OTHER PROCEDURES

Arguments for…

• Studies of ketamine in abdominal, orthopaedic, gastric, hepatic and renal surgery showed a reduction in postoperative pain and opioid use when used as an adjuvant to morphine, either epidurally or intravenously Subramaniam et al 2004

CLINICAL PRACTICE

Arguments against…

• Ketamine is associated with a risk of adverse effects on the central nervous system

PROSPECT RECOMMENDATIONS

• Postoperative ketamine cannot be recommended at this time (Grade D) due to a lack of procedure-specific evidence, and due to associated side-effects that may hinder early ambulation, despite some evidence of analgesic efficacy in other procedures

HERNIORRAPHY-SPECIFIC EVIDENCE

Arguments for…

• Postoperative continuous infusion of the wound with local anaesthetic showed a significant benefit, compared with placebo, for reducing pain scores for up to two days after surgery Lau et al 2003 Click here for more information

Arguments against…

• Postoperative continuous infusion of the wound with local anaesthetic did not significantly reduce supplementary analgesic requirements compared with placebo Oakley et al 1998 Click here for more information

PROSPECT RECOMMENDATIONS

• Postoperative continuous wound infusion with local anaesthetic cannot be recommended at this time, despite evidence for its analgesic efficacy, because of limited data (Grade D)

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Pre- plus intra- plus postoperative inguinal nerve block/field block/infiltration was superior to placebo for reducing pain scores on lying, sitting and walking at 8 h and on days 1–5 (p<0.05) but there was no significant difference at 10 or 30 days (n=70) Fischer et al 2000
• Pre- plus intra- plus postoperative inguinal nerve block/field block/infiltration was superior to placebo for reducing the proportion of patients requiring supplementary ibuprofen at 0 and 2 days (p<0.05) (n=70) Fischer et al 2000
• Postoperative wound instillation with bupivacaine in repeat doses via a catheter was similar to systemic conventional NSAIDs for reducing pain scores at 0–30 h, and for reducing use of supplementary metamizole (n=104) Zieren et al 1999

Arguments against…

• Postoperative single/repeat bolus of local anaesthetic by a catheter in the wound did not reduce pain scores compared with placebo or no such treatment Cameron et al 1985 Click here for more information
• Postoperative single/repeat bolus of local anaesthetic by a catheter in the wound was of no benefit for reducing supplementary analgesic requirements compared with placebo or no such treatment (n=101) Cameron et al 1985
• For postoperative wound instillation, ropivacaine and bupivacaine were similar for postoperative VAS pain scores at rest and on movement on days 0 and 1, for supplementary analgesic requirements, and for the incidence of PONV (n=51) Vintar et al 2002

PROSPECT RECOMMENDATIONS

• Postoperative single/repeat dose of local anaesthetic by catheter in the wound is not recommended because of a lack of analgesic effect (Grade A)
• Postoperative subcutaneous infiltration cannot be recommended at this time because of limited data (Grade D)

HERNIORRAPHY-SPECIFIC EVIDENCE – STUDY INFORMATION

Arguments for…

• Subfascial local anaesthetic showed a significant benefit over subcutaneous local anaesthetic for reducing pain scores during the first postoperative hour, but there was no difference in supplementary analgesic requirements Yndgaard et al 1994 Click here for more information

PROSPECT RECOMMENDATIONS

• Subfascial infiltration with local anaesthetics cannot be recommended in preference to subcutaneous infiltration at this time because of limited data (Grade D)