Recent literature

• Four out of four studies found that conventional NSAID was superior to placebo or no treatment. In two studies pre-operative conventional NSAID significantly reduced postoperative VAS pain scores at 2 h (at rest and on coughing; Akarsu 2004) and 2, 4, 6 and 12 h (Karaman 2006), compared with placebo. In one study, pre- and intra-operative conventional NSAID significantly reduced postoperative VAS pain scores at 6 h compared with control (no treatment) (Yan 2004). In one study postoperative conventional NSAID significantly increased pain intensity difference (VAS) scores compared with placebo (at 30 min–24 h) and compared with morphine (at 30 min and 1–12 h) groups (Bikhazi 2004)
• In one study, time to first request for rescue analgesia was significantly longer, and total analgesic consumed was less, following pre-operative conventional NSAID administration, compared with placebo (Akarsu 2004); in another study, PCA morphine consumption was significantly reduced in the group receiving pre-operative conventional NSAID at 2, 4, 6, 12 and 24 h compared with the saline control group (Karaman 2006)
• In one study there was a significantly higher incidence of nausea and vomiting in the placebo group compared with the pre-operative conventional NSAID group (Akarsu 2004). In two studies there were no significant differences between the incidence of adverse events in the conventional NSAID and placebo groups (Bikhazi 2004; Karaman 2006)

No change to recommendations

• Three studies out of three showed COX-2-selective inhibitor superior to control for reducing pain scores:
  • In one study, the pre-operative COX-2-selective inhibitor significantly reduced postoperative VAS pain scores at 1, 2, 4, 6, 8 and 12 h compared with placebo (Karamanlioglu 2004)
  • In one study peri-operative COX-2-selective inhibitor, alone and in combination with gabapentin, significantly reduced postoperative VAS pain scores at rest at 20, 24, 28, 32, 44, 48, 52 and 56 h compared with placebo; VAS pain scores at sitting were significantly reduced in the COX-2-selective inhibitor plus gabapentin group at 20h, and following the COX-2-selective inhibitor both alone and in combination with gabapentin at 24, 28, 32, 44, 48, 52, and 56 h compared with placebo; VAS pain scores at peak expiration were significantly reduced following administration of the COX-2-selective inhibitor alone and in combination with gabapentin at 20, 24, 28, 32, 44, 48, 52, and 56 h compared with placebo; VAS pain scores during coughing were significantly reduced in the COX-2-selective inhibitor plus gabapentin group at 20, 24, 28, 32 h, and following administration of the COX-2-selective inhibitor both alone and in combination with gabapentin at 44, 48, 52 and 56 h, compared with placebo (Gilron 2005)
  • In one study, peri-operative COX-2-selective inhibitor, alone and in combination with gabapentin, significantly reduced VRS postoperative pain scores at rest at 4, 8, 16 and 20 h, compared with placebo; COX-2-selective inhibitor in combination with gabapentin significantly reduced VRS pain scores at rest at 12 and 24 h compared with placebo; COX-2-selective inhibitor alone, and in combination with gabapentin, significantly reduced VRS postoperative pain scores during movement at 8 h, and the COX-2 inhibitor alone also showed a significant reduction at 20 h, compared with placebo (Turan 2006)
• Three out of three studies showed COX-2-selective inhibitor superior to placebo for reducing supplementary analgesic consumption
  • Total and incremental supplementary analgesic consumptions were significantly less in the pre-operative COX-2-selective inhibitor group compared with placebo at 1, 2, 4, 6, 8, and 12 h postoperatively (Karamanlioglu 2004)
  • Cumulative morphine consumption was significantly less in the COX-2-selective inhibitor plus gabapentin group compared with placebo at 2, 3, 4, 8, 20, 24, 28 and 32 h postoperatively, and interval morphine consumption was significantly less in the COX-2-selective inhibitor group at 4–8, 8–20, 20–32, 32–44 and 44–56 h and in the COX-2-selective inhibitor plus gabapentin group at all time points recorded after surgery, compared with placebo (Gilron 2005)
  • PCA morphine requirement was significantly less following administration of the COX-2-selective inhibitor, alone and in combination with gabapentin at 1, 8, 12, 16, 24, and 30 h postoperatively, and at 20 h following the COX-2-selective inhibitor plus gabapentin, compared with placebo (Turan 2006)
• Three out of three studies showed that COX-2-selective inhibitors are not superior to placebo for reducing the incidence of adverse effects
  • In two studies there was no significant difference in the incidence of adverse events between the COX-2-selective inhibitor group and control (Gilron 2005; Karamanlioglu 2004)
  • In one study there was no significant difference between COX-2 inhibitor alone or gabapentin alone compared with placebo, but there was a significantly lower incidence of nausea in the combination of COX-2-selective inhibitor and gabapentin group compared with the placebo group (Turan 2006)

No change to recommendations

• One study showed that pre-operative oral clonidine did not significantly reduce pain scores both at rest and during movement compared with placebo at all time points assessed (Oofuvong 2005); one study showed that pre- and postoperative oral clonidine significantly reduced pain scores compared with placebo at all time points assessed (Hidalgo 2005) 
• One study showed that intra-operative dexmedetomidine had no effect on pain scores at rest and during movement compared with placebo, both in the PACU and 0–48 h after surgery (Gurbet 2006)
• Morphine consumption was not significantly different between clonidine and placebo groups at all time points assessed (Hidalgo 2005; Oofuvong 2005)
• Patients in the intra-operative dexmedetomidine group consumed significantly less postoperative morphine compared with the placebo group, both in the PACU and 0–48 h after surgery (Gurbet 2006)

Systemic clonidine: no change to recommendation
Dexmedetomidine: limited data, so not recommended at the current time

• One study showed that pre-operative morphine did not significantly reduce subjective pain scores (0–10) compared with saline control (Goldstein 2005)
• One study showed that postoperative IV morphine significantly reduced VRS pain scores compared with placebo 2 min after administration, but not at any other time point assessed (5, 10 and 15 min) (Larijani 2004)
• One study showed that intraoperative pethidine significantly reduced VAS pain scores at rest at 0–120 min after surgery compared with postoperative pethidine (Mavioglu 2005)
• One study showed a significant reduction in supplemental analgesic demands between 15 and 30 min postoperatively, cumulative PCA demands, cumulative pethidine consumption after the first 24 h, and additional pethidine consumption during the first 2 h, in the intraoperative pethidine group compared with the postoperative pethidine group (Mavioglu 2005)

No change to recommendations

• One study showed that postoperative tramadol significantly reduced VAS pain scores compared with saline control at all time points assessed (0–24 h) (Kocabas 2005)
• One study demonstrated a significant reduction in PCA morphine requirements at 1, 2, 3, 4, 8, 12, 16, 20 and 24 h after surgery in the postoperative tramadol group compared with the saline control group (Kocabas 2005)

No change to recommendation

• One study showed that pre-operative spinal morphine significantly reduced VAS pain scores at rest and during coughing at all time points assessed (up to 20 h post-surgery) compared with control (no treatment) (Karaman 2006)
• One study showed that intra-operative spinal morphine significantly reduced VAS pain scores at 0, 1, 2, 4, and 8 h after surgery compared with IV morphine (Togal 2004)
• One study showed that pre-operative spinal morphine significantly reduced postoperative morphine consumption in 20 h compared with control (no treatment) (Karaman 2006)
• One study showed that postoperative total morphine consumption and PCA demands were significantly lower in the group receiving intra-operative spinal morphine compared with the IV morphine group during postoperative 24 h (Togal 2004)

No change to recommendations

• One study showed that postoperative IV PCA droperidol (50 µg droperidol premixed with 1 mg/ml morphine compared with morphine alone) significantly reduced VRS pain scores at rest (at 72 h) and on coughing/movement (at 48 and 72 h) compared with control (no droperidol). Morphine consumption was significantly lower in the postoperative IV droperidol group at all time points assessed, when compared with control (no droperidol) (Lo 2005)

Not recommended for pain relief due to limited procedure-specific evidence (although droperidol has proven effects on nausea and vomiting)

• One study showed that pre-operative antihistamine, combined with either a 1.2:1 or a 4.8:1 ratio of antihistamine-morphine mixture for postoperative PCA, did not significantly reduce VAS pain scores at rest or supplemental analgesic requirements at any time point assessed (0–24 h) compared with saline control (Lin 2005)
• One study showed that neither pre-operative antihistamine alone nor postoperative antihistamine alone significantly reduced VAS pain scores at rest or during movement compared with saline control (Chia 2004)
• One study showed that patients in the pre-operative antihistamine alone group consumed significantly less morphine at 3, 6, 12, and 24 h postoperatively compared with patients in the postoperative antihistamine alone and saline control groups (Chia 2004)

Not recommended due to limited evidence of analgesic efficacy

• One study showed that pre- and intra-operative beta-blockers had no effect on VAS pain scores at rest and during movement at all time points assessed compared with saline control (Chia 2004)
• Patients receiving beta-blockers consumed significantly less PCA morphine at all time points assessed, and the mean total morphine consumption was significantly less, compared with saline control (Chia 2004)

Not recommended because of limited evidence of analgesic efficacy

Single bolus wound instillation

• One study showed that intra-operative single bolus wound instillation (topically on to peritoneum for 10 min) significantly reduced NRS pain scores at 60 min after surgery compared with placebo (pain assessed every 15 min from 0–120 min after surgery; all other time points not significantly different) (Heid 2005)
• There were no differences in cumulative morphine consumption or adverse effects observed between the wound instillation and placebo groups (Heid 2005)

Not recommended currently due to limited procedure-specific evidence

Continuous wound infusion

• One study showed that postoperative continuous wound infusion significantly reduced VAS pain scores compared with no wound infusion at rest at 4, 5, 6, and 12h, on coughing at 0–24 h, and on leg raising at 3, 4, 5, 6, and 12 h after surgery (Gupta 2005)
• Significantly less rescue analgesia was consumed in the continuous wound infusion group compared with the no wound infusion group (pentazocine administered 0–6 h, diclofenac administered 6–24 h) (Gupta 2005)

Not recommended currently due to limited procedure-specific evidence

PCA wound infusion

• One study (published January 2004–June 2006) showed that there were no significant differences in analgesic outcomes between two doses of ropivacaine delivered via PCA wound infusion (Zohar 2004)

Not recommended currently due to limited procedure-specific evidence  

• One study showed that IP LA + IP conventional NSAID + IP weak opioid significantly reduced VAS pain scores compared with IP LA + IP conventional NSAID (at 1 and 2 h) and IP LA + IP weak opioid (at 2 h) (Pirbudak 2004)
• Time to first analgesic request was significantly longer, and total supplementary analgesic consumption was significantly lower, in the IP LA + IP conventional NSAID + IP weak opioid group compared with the IP LA + IP conventional NSAID group and the IP LA + IP weak opioid group (Pirbudak 2004)

No change to recommendations

• One study showed that there were no significant differences in analgesic efficacy between pre-operative and postoperative epidural analgesia (LA + ketamine) (DeCastro 2005)
• One study showed that there were no significant differences in VAS pain scores at rest and during coughing (at 4, 8, and 21 h), or total morphine consumption, between the postoperative epidural 0.1% ropivacaine + fentanyl group and the postoperative epidural 0.2% ropivacaine group (Thienthong 2004)

No change to recommendations

Two studies showed that abdominal laparoscopic hysterectomy significantly reduced pain scores compared with abdominal hysterectomy (Garry 2004; Garry 2004). One study showed that laparoscopic hysterectomy significantly reduced pain scores compared with abdominal hysterectomy (Learman 2004). One study showed that vaginal hysterectomy significantly reduced pain compared with abdominal hysterectomy (Silva 2006)

 Vaginal hysterectomy studies:

• Two studies showed that there were no significant differences in pain scores between vaginal hysterectomy and vaginal laparoscopic hysterectomy (Garry 2004; Garry 2004)
• One study showed that electrosurgical bipolar vessel sealing significantly reduced pain compared with traditional suturing in vaginal hysterectomy (Cronjé 2005)

Further data are required before any changes can be made to the recommendations