Prevention of pain on injection with propofol
Clinical bottom line:Without any analgesic intervention, the incidence of pain on injection of propofol was about 70%. Lidocaine (lignocaine) given with a tourniquet 30 to 120 seconds before injection of propofol was about the most effective intervention, with NNTs of below 2. With lidocaine mixed with propofol the best NNT was 2.4. Pethidine given with a tourniquet and metoclopramide given with a tourniquet also seemed to be effective.
A disadvantage of the induction agent propofol is that it causes pain on injection. It can cause distress to patients, and is considered to be a serious clinical problem in anaesthesia. A number of different interventions have been tried to reduce or prevent the pain on injection, and a systematic review tells us which of these interventions is likely to be effective.
Systematic review
P Picard, MR Tramèr. Prevention of pain on injection with propofol: a quantitative systematic review. Anesthesia and Analgesia 2000 90: 963-969.
Date review completed: September 1999
Number of trials included: 56
Number of patients: 6264
Control group: placebo
Main outcomes: complete absence of pain
Inclusion criteria were randomised controlled trials that tested the analgesic effect of prophylactic interventions compared with placebo or no treatment controls. For temperature effects, propofol at room temperature was regarded as the control. Included trials could be in any language.
Searching included MEDLINE, EMBASE and the Cochrane Library.
Findings
There were 56 reports with 6264 patients. Quality of studies was low, with a median score of 2 (range 1-4) on a scale of 1-5. Without any analgesic intervention, the incidence of pain on injection of propofol was about 70%. There was no evidence of any relationship between the incidence of pain on injection and the size of catheter used or speed of injection. Neither cooling nor warming propofol before injection was effective in reducing the incidence of pain.
The main analgesic interventions for which there were at least two trials are shown in the Table. Lidocaine given with a tourniquet 30 to 120 seconds before injection of propofol was about the most effective intervention, with NNTs of below 2. With lidocaine mixed with propofol the best NNT was 2.4. Pethidine given with a tourniquet and metoclopramide given with a tourniquet also seemed to be effective.
| Patients without pain | ||||
| Treatment | Number of trials | Active number/total | Control number/total | NNT` (95%CI) |
| Lidocaine before propofol injection | ||||
| 10 mg | 6 | 136/301 | 91/297 | 6.9 (4.5 to 15) |
| 20 mg | 2 | 48/68 | 32/70 | 4.0 (2.5 to 11) |
| Lidocaine mixed with propofol | ||||
| 5-8 mg | 4 | 77/243 | 38/241 | 6.3 (4.3 to 12) |
| 10-12 mg | 10 | 173/389 | 77/401 | 4.0 (3.2 to 5.3) |
| 20-24 mg | 9 | 203/329 | 66/332 | 2.4 (2.1 to 2.9) |
| 30-40 mg | 6 | 105/219 | 41/201 | 3.6 (2.8 to 5.3) |
| Lidocaine with tourniquet | ||||
| 20 mg | 2 | 35/46 | 11/47 | 1.9 (1.4 to 2.8) |
| 40 mg | 4 | 82/97 | 28/99 | 1.8 (1.5 to 2.2) |
| Opioids | ||||
| Fentanyl 100-150 µg | 5 | 91/149 | 50/149 | 3.6 (2.6 to 5.9) |
| Alfentanil 1000 µg | 6 | 146/194 | 81/185 | 3.2 (2.5 to 4.5) |
| Pethidine 40 mg, tourniquet | 2 | 51/66 | 16/65 | 1.9 (1.5 to 2.6) |
| Metoclopramide | ||||
| 5 or 10 mg before | 4 | 105/135 | 55/135 | 2.7 (2.1 to 4.0) |
| 10 mg, tourniquet | 3 | 52/75 | 18/75 | 2.2 (1.7 to 3.0) |
| Temperature | ||||
| Cold (4ºC) | 6 | 58/169 | 51/173 | 21 (7 to -20) |
| Warm (37ºC) | 3 | 43/95 | 35/106 | 8 (4 to -84) |
| Negative upper CI of NNT indicates not significantly different from control | ||||
Comment
Intravenous lidocaine (0.5 mg/kg) should be given with a tourniquet on the forearm 30-120 seconds before injection of propofol. This will prevent pain in about 60% of patients so treated.
For Pain acute/other
Perioperative