Table 4.
Schematic overview of studies involving remifentanil in human experimental pain models
| Reference | Dose | Model (pain assessment) | Main findings | |
|---|---|---|---|---|
| Acute models | [68] (n= 7) | 0.05 and 0.15 µg min−1 kg−1 iv | Heat skin stimulation (pulses 0.3°°C under −1°C above PDT) evaluated by positron emission tomography | Remifentanil decreased the pain induced brain activation |
| [65] (n= 14) | 1 and 2 ng ml−1 iv | Single and repeated skin and intramuscular electrical stimulation PDT Deep pressure PTT | Pain from all modalities was decreased. Remifentanil induced HA was detected by pressure pain | |
| [69] (n= 10) | 0.025, 0.05 and 0.1 µg min−1 kg−1 iv | Tibial pressure evaluated by cerebral blood flow | Pain induced increase in cerebral blood flow was attenuated | |
| [66] (n= 18/14) | 0.1 µg min−1 kg−1 iv | Heat skin stimulation PDT and V s−1 to 1 min of 45°°C | PDT ↑ VAS ↓ | |
| [64] (n= 20) | 0.01 increasing to 0.17 µg min−1 kg−1 iv | Heat skin stimulation PDT (0.5°C s−1) | PDT ↑ in a dose-related manner | |
| [63] (n= 14) | 1 and 2 ng ml−1 iv (target control) | Skin and intramuscular repeated electrical stimulation PDT | PDT ↑ in both tissues, but mostly in the muscles | |
| Models inducing hyperalgesia | [71] (n= 15) | 0.05 µg min−1 kg−1 iv | Continuous electrical skin stimulation Ongoing pain (numeric rating scale) Area of secondary HA to pinprick (von Frey) | Electrically evoked pain ↓ Area of secondary HA to pinprick ↓ (during infusion). Post infusion HA was detected |
| [72] (n= 15) | 0.1 µg min −1kg−1 iv | Continuous electrical skin stimulation Ongoing pain (numeric rating scale) Area of secondary HA to pinprick (von Frey) | Electrically evoked pain ↓ Area of secondary HA to pinprick ↓ (during infusion). Post infusion HA was detected | |
| [33] (n= 13) | 0.05–0.1 µg min−1 kg−1 iv | Continuous electrical skin stimulation Ongoing pain (numeric rating scale) Area of secondary HA to pinprick (von Frey) | Dose-dependent reduction of evoked pain and HA. Post infusion HA was detected | |
| [31] (n= 12) | 0–6 ng ml−1 iv (target control) | Freeze lesion. Primary HA to electrical stimulation, stroking, pinprick and blunt pressure | No HA to electrical stimulation was seen. Electrical pain ↓ HA to blunt pressure ↓ twice as much as to pinprick. Stroking did not evoke pain | |
| [73] (n= 10) | 3.1 ng ml−1 iv (target control) | Heat-capsaicin sensitisation area of allodynia/secondary HA to brushing/pinprick von Frey Heat skin stimulation in inflamed skin (three different temperatures for 5 min.) numeric raring scale | Area of allodynia and HA ↓ Heat pain ↓ Post infusion HA was detected | |
| [66] (n= 18/14) | 0.1 µg min−1 kg−1 iv | Heat/capsaicin secondary area of HA to pinprick stimulation and brushing | The area of HA for both modalities was reduced |
In the column ‘model’ the method for pain assessment is normal font, and the method for pain induction is bolded. Abbreviations: pain detection threshold (PDT), pain tolerance threshold (PTT), area under curve (AUC), visual analogue scale score (VAS), hyperalgesia (HA).