Table 6

Results of included studies

ReferenceInterventionBaseline pain scoresPostintervention pain scoresStatistical difference between intervention and controlSecondary outcomesAdverse effects
Vahidi et al 32 Intravenous lidocaine versus intravenous morphine sulfateMean VAS 7.50±1.93Intervention:
15 min: 5.75±1.77
30 min: 4.25±1.48
15 min: 7.00±1.83
30 min: 6.50±1.73
15 min: mean difference 1.25 (95% CI 0.095 to 2.405)
30 min: mean difference 2.25 (95% CI 1.218 to 3.282)
Morris-Stiff et al 35 Gabapentin:
median dose 1271 mg/24 hours
Median VAS 9Day 4: 7 (p=0.001)
Day 7: 7 (p=0.0002)
Day 14: 6 (p=0.0004)
Day 28: 5 (p=0.0003)
No controlReduction in night pain in 15/16 patients
Reduction in opioid requirements in 5/17. No increase in opioid dose required
Aurilio et al 36 Buprenorphine transdermal patch+epidural ropivacaine+morphine versus placebo patch+epidural ropivacaine+morphine aloneMean VAS:
Intervention 84.9±3.38
Control 84.8±3.41
At end point:
Intervention 10.31±2.13
Control 19.4±1.95
Intervention versus control (p<0.0001 95% CI −10.4 to −8.3)Statistical significant improvements in intervention vs control in SF-MPQ total, SF-MPQ PPI, Sleepinterference (All p<0.0001)
Lower number of patients requiring rescue morphine
No significant differences in the neurobehavioural status of the patients (p<0.165)
No side effects in 18 patients in intervention versus 8 in control
More SEs (drowsiness, fatigue, constipation, nausea) in control
In the control group, two patients (4.7%) suffered significant nausea causing them to withdraw from trial
Aurilio et al 28 Buprenorphine transdermal patch+epidural ropivacaine+morphine versus epidural ropivacaine+morphine aloneMean VAS:
Intervention 85
Control 85
At 15 days:
Intervention 20
Control 38
At 30 days:
Intervention 10
Control 20
No statistical tests performedHours of sleep
3.5 to 5 to 8 hours vs 3.5 to 4.5 to 6 hours in control
No patients for additional morphine in intervention, 11 in control
No side effects in 12 patients in intervention versus 6 in control
More SEs (drowsiness, fatigue, constipation, nausea) in control
1 withdrawal in control due to nausea
Mitchell and Fallon33 Intravenous ketamine versus intravenous normal salinePain relief score (mean):
Intervention 50
Control 58
Mean ‘average pain score’:
Intervention 5.9
Control 5.8
Pain relief score:
Intervention (24 hours post): 65
Control (24 hours post): 56
Mean ‘average pain score’:
Intervention (24 hours post): 5.1
Control (24 hours post): 6.3
17% difference in means of pain relief scores (95% CI 0.2, 33.8) in favour of ketamine versus control.
Statistical significance (p<0:05) improvement in the average daily pain scores in the ketamine group
Improvement in effect of pain on general activity (p<0.03) and enjoyment of life (p<0.004)
No significant difference in opioid consumption
In ketamine group 33% (n=6) reported feeling more emotional than usual 24 hours after infusion, only 6% (n=1) of placebo group (OR of 7.7, p<0:05)
7 patients withdrew for reasons not related to intervention
Persson et al 34 Intravenous ketamine versus intravenous morphineBaseline pain ratings ranged from 0.3 to 10Ketamine 0.30 mg/kg: total pain relief in 7/8 patients
Ketamine 0.45 mg/kg: total pain relief in 8/8 patients
Pain relief (median value) of approximately 50% at 60 min
At 5 min: 0.45 mg/kg dose statistical significant difference (p=0.010) and 0.30 mg/kg dose (p=0.05)
The 0.15 mg/kg dose was not significant (p>0.05) At 10 min: only 0.45 mg/kg significantly different from morphine (0.05 level)
At peak effects 0.45 mg/kg ketamine versus 10 mg morphine (5 and 20 min, respectively): not significantly different (p<0.10, Wilcoxon test)
NoneKetamine: all patients had perceptual disturbances and psychotropic effects (dose dependent)
At 0.45 mg/kg dose all had ‘unacceptable’ SE
Highest dose ketamine: mean BP rise ~10%
HR changes within the limits of +10 beats/min for all doses
  • PPI, present pain intensity; SF-MPQ, Short-Form McGill Pain Questionnaire; VAS, visual analogue scale.