Reduction of pain on injection of propofol: combination of pretreatment of remifentanil and premixture of lidocaine with propofol

Pretreatment with Low-Dose Esketamine for Reduction of Propofol Injection Pain: A Randomized Controlled Trial

Background

Propofol-induced injection pain is a common adverse effect during the induction of general anesthesia. The purpose of this study is to investigate the effect of low-dose esketamine in preventing propofol injection pain.

Methods

In this double-blind, randomized, controlled trial, patients scheduled for elective ear surgery under general anesthesia received either normal saline (NS), or 40 mg lidocaine, or 0.15 mg/kg esketamine 30 seconds before manual injection of propofol. The primary outcome of this study was the incidence of propofol injection pain. The secondary outcomes included injection pain score, vital signs, total dosage of vasoactive drugs used within 5 minutes after induction, and adverse events related to drugs.

Results

A total of 105 patients were included. Compared with the NS group (67%), pretreatment with esketamine and lidocaine significantly reduced the incidence of injection pain to 29% and 33%, respectively (both P < 0.05); however, no significant difference was found between the esketamine and lidocaine groups. The median of injection pain score was significantly lower in the esketamine and lidocaine groups (both median (interquartile range) = 0 (0–1)) than that in the NS group (1 (0–2); P < 0.05). In addition, compared with the NS and lidocaine groups, preinjection esketamine provided more stable hemodynamic parameters within 5 minutes after induction (P < 0.05). No statistical difference was found in adverse events among the three groups.

Conclusions

Pretreatment with a low-dose esketamine can not only reduce the incidence of propofol injection pain but also provide a more stable circulation in patients after anesthesia induction. This convenient, well-tolerated, and economic treatment appears as an option to be routinely applied in clinic practice. Clinical Trial Registration. This trial is registered with https://www.chictr.org.cn/showproj.aspx?proj=136690 (the number for the trial registration isChiCTR2100052742).

Efficacy of Pre-Treatment with Remimazolam on Prevention of Propofol-Induced Injection Pain in Patients Undergoing Abortion or Curettage: A Prospective, Double-Blinded, Randomized and Placebo-Controlled Clinical Trial

Background

Propofol-induced injection pain (PIP) is a well-known problem in general anesthesia. We hypothesized that pre-treatment with remimazolam prevents PIP in patients undergoing abortion or curettage.

Materials and Methods

In this prospective, single-center, double-blinded, randomized, placebo-controlled clinical trial, adult patients aged 18 to 60 undergoing abortion or curettage were randomly assigned to three groups. Group Lido received system lidocaine (a bolus of 0.5 mg kg⁻¹, iv). Group Remi received remimazolam (a bolus of 0.1 mg kg⁻¹, iv). Group NS received identical volumes of 0.9% normal saline. Sixty seconds after the injection of lidocaine, remimazolam or saline, patients were injected with propofol at a rate of 12 mL/min until the loss of consciousness. The primary outcome was the incidence of PIP at the time of induction using 4-point scale. Secondary outcomes included propofol-induced injection pain, vital signs, the characteristics of anesthesia and surgery, and adverse events.

Results

The incidence of patients with PIP was higher in group NS than that in group Lido and group Remi (75.7, 44.3, and 42.9%, respectively, p < 0.001). The percentages of patients with moderate PIP were higher in group NS than that in group Lido and group Remi (20.0, 2.9, and 1.4%, respectively, p < 0.001). Moreover, the consumption of propofol and the incidence of adverse event (hypoxemia and chin lifting) in group Remi were lower than that in group NS and Lido, and less patients got physical movement and cough in group Remi. The recovery time in group NS was longer than that in group Lido and Remi.

Conclusion

Our findings indicate that pre-treatment with remimazolam reduced the incidence and intensity of PIP in abortion or curettage patients, equivalent to that of lidocaine without severe adverse effects.

Trial Registration

Chinese Clinical Trial Registry (identifier: ChiCTR2100041805).

Comparison Between Intravenous Nalbuphine and Lidocaine in Reducing Propofol-Induced Injection Pain During Gastroscopy: A Randomized Controlled Trial

Introduction

Intravenous propofol anesthesia is widely used in painless endoscopy. However, propofol injection pain is a common adverse effect. This study investigated the effects of nalbuphine and lidocaine in reducing propofol-induced injection pain.

Methods

In this double-blind, randomized study, 330 patients were randomly divided into three groups by using a random number table: the nalbuphine group (N), lidocaine group (L), and control group (C). The N, L, and C groups received either 0.1 mg/kg nalbuphine, 0.5 mg/kg lidocaine, or an equivalent volume of normal saline, respectively, as pretreatment drug. Then propofol was manually injected. The primary outcome of this study was the incidence of propofol-induced injection pain, and secondary outcomes included the severity of propofol-induced injection pain, vital signs, and adverse events, including hypotension, bradycardia (< 50 beats/min), hypoxemia (SpO₂ < 90%), drowsiness, physical movement, and cough.

Results

The percentages of patients with propofol injection pain were higher in group C than in group N and group L (64, 34, and 27%, respectively, p < 0.05). The percentage of patients with severe pain after propofol injection was significantly higher in group C than in group N and group L (12, 1, and 0%, respectively, p < 0.05). The doses of propofol in group C and group L were significantly higher than that in group N. More patients suffered hypoxemia in group N than in group C and group L. Then, less patients got physical movement and cough in group N.

Conclusions

Pretreatment with nalbuphine 0.1 mg/kg was effective in reducing propofol-induced injection pain and propofol consumption. Propofol combined with nalbuphine can be safely and effectively used during gastroscopy.

Trial Registration

Chinese Clinical Trial Registry; ChiCTR1900025438.

Pain on propofol injection: Causes and remedies

Pain on propofol injection (POPI) is a minor problem that all anesthetists face every day. Introduction of several new formulations and hundreds of clinical trials have failed to find its remedy with just one intervention in all patients. This article highlights the causes of POPI and interventions that are used to eliminate this pain in current practice. Relevant articles from Medline and Embase databases were searched and included in this descriptive review with the following conclusions: (1) POPI is due to irritation of venous adventitia leading to release of mediators such as kininogen from kinin cascade. (2) When two or more drugs or measures are used, the incidence of POPI decreases considerably. Hence, the approach to eliminating POPI should be multimodal. (3) Any regimen that includes a drug having local anesthetic effect combined with central sedative/analgesic and rapid injection into a large vein should definitely reduce the risk of POPI to negligible levels.

Comparative evaluation of the effect of remifentanil and 2 different doses of esmolol on pain during propofol injection: A double-blind, randomized clinical consort study

BACKGROUND

Propofol is associated with pain during injection, which is stressful to patients. The present study was designed to investigate the analgesic effect of pretreatment with remifentanil and esmolol in minimizing propofol injection pain, compared with placebo.

METHODS

In a randomized, double-blind, prospective trial, 120 patients, scheduled for elective dental surgery under general anesthesia, were randomized to 1 of the 4 treatment arms (n = 30 each) receiving normal saline, remifentanil 0.35 μg/kg, esmolol 0.5 mg/kg, and 1 mg/kg before administration of propofol. During injection of 1% propofol 0.5 mg/kg, pain was evaluated by a 4-point score (0 = none, 1 = mild, 2 = moderate, 3 = severe). Any adverse effects such as hypotension and bradycardia were recorded during the perioperative periods.

RESULTS

In all, 120 patients completed this study. There were no significant differences in terms of demographic data. The incidence of pain on injection of propofol was 11 (36.7%) with remifentanil 0.35 μg/kg, 12 (40%) with esmolol 0.5 mg/kg, and 11 (36.7%) with esmolol 1 mg/kg, compared with 25 (83.3%) with normal saline (respectively, P < 0.05). There were no significant differences in the incidence of pain between groups with remifentanil 0.35 μg/kg, and esmolol 0.5 mg/kg and 1 mg/kg. There were no emergence reactions such as hypotension and bradycardia in all groups.

CONCLUSIONS

Pretreatment with esmolol 0.5 mg/kg and 1 mg/kg and remifentanil 0.35 μg/kg equally decreased pain during propofol injection.

Lidocaine for reducing propofol-induced pain on induction of anaesthesia in adults

BACKGROUND

Pain on propofol injection is an untoward effect and this condition can reduce patient satisfaction. Intravenous lidocaine injection has been commonly used to attenuate pain on propofol injection. Although many studies have reported that lidocaine was effective in reducing the incidence and severity of pain, nevertheless, no systematic review focusing on lidocaine for preventing high-intensity pain has been published.

OBJECTIVES

The objective of this review was to determine the efficacy and adverse effects of lidocaine in preventing high-intensity pain on propofol injection.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10), Ovid MEDLINE (1950 To October 2014), Ovid EMBASE (1988 to October 2014), LILACS (1992 to October 2014) and searched reference lists of articles.We reran the search in November 2015. We found 11potential studies of interest, those studies were added to the list of 'Studies awaiting classification' and will be fully incorporated into the formal review findings when we update the review.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) using intravenous lidocaine injection as an intervention to decrease pain on propofol injection in adults. We excluded studies without a placebo or control group.

DATA COLLECTION AND ANALYSIS

We collected selected studies with relevant criteria. We identified risk of bias in five domains according to the following criteria: random sequence generation, allocation concealment, adequacy of blinding, completeness of outcome data and selective reporting. We performed meta-analysis by direct comparisons of intervention versus control. We estimated the summary odds ratios (ORs) and 95% confidence intervals using the random-effects Mantel-Haenszel method in RevMan 5.3. We used the I(2) statistic to assess statistical heterogeneity. We assessed overall quality of evidence using the GRADE approach.

MAIN RESULTS

We included 87 studies, 84 of which (10,460 participants) were eligible for quantitative analysis in the review. All participants, aged 13 years to 89 years, were American Society of Anesthesiologists (ASA) I-III patients undergoing elective surgery. Each study was conducted in a single centre in high- , middle- and low-income countries worldwide. According to the risk of bias assessment, all except five studies were identified as being of satisfactory methodological quality, allowing 84 studies to be combined in the meta-analysis. Five of the 84 studies were assessed as high risk of bias: one for participant and personnel blinding, one for incomplete outcome data, and three for other potential sources of bias.The overall incidence of pain and high-intensity pain following propofol injection in the control group were 64% (95% CI 60% to 67.9%) and 38.1% (95% CI 33.4% to 43.1%), respectively while those in the lidocaine group were 30.2% (95% CI 26.7% to 33.7%) and 11.8% (95% CI 9.7% to 13.8%). Both lidocaine admixture and pretreatment were effective in reducing pain on propofol injection (lidocaine admixture OR 0.19, 95% CI 0.15 to 0.25, 31 studies, 4927 participants, high-quality evidence; lidocaine pretreatment OR 0.13, 95% CI 0.10 to 0.18, 43 RCTs, 4028 participants, high-quality evidence). Similarly, lidocaine administration could considerably decrease the incidence of pain when premixed with the propofol (OR 0.19, 95% CI 0.15 to 0.24, 36 studies, 5628 participants, high-quality evidence) or pretreated prior to propofol injection (OR 0.14, 95% CI 0.11 to 0.18, 52 studies, 4832 participants, high-quality evidence). Adverse effects of lidocaine administration were rare. Thrombophlebitis was reported in only two studies (OR not estimated, low-quality evidence). No studies reported patient satisfaction.

AUTHORS' CONCLUSIONS

Overall, the quality of the evidence was high. Currently available data from RCTs are sufficient to confirm that both lidocaine admixture and pretreatment were effective in reducing pain on propofol injection. Furthermore, there were no significant differences of effect between the two techniques.

Effects of a fentanyl-propofol mixture on propofol injection pain: a randomized clinical trial

BACKGROUND

Propofol injection pain is a common problem that can be very distressing for patients. We compared the effects of injection with saline followed by injection with a fentanyl-propofol mixture, injection with fentanyl followed by a propofol injection, and injection with saline followed by propofol alone on propofol injection pain.

METHODS

The patients were assigned randomly to one of three groups. A rubber tourniquet was placed on the forearm to produce venous occlusion for 1 min. Before anesthesia induction, group C (control, n = 50) and group M (fentanylpropofol mixture, n = 50) received 5 ml of isotonic saline, while group F (fentanyl, n = 50) received 2 µg/kg of fentanyl. After the tourniquet was released, groups C and F received 5 ml of propofol and group M received 5 ml of a mixture containing 20 ml of propofol and 4 ml of fentanyl. At 10 s after the study drugs were given, a standard question about the comfort of the injection was asked of the patient. We used a verbal rating scale to evaluate propofol injection pain. Statistical analyses were performed with Student's t-tests and Fisher's exact tests; P < 0.05 was considered to indicate statistical significance.

RESULTS

The demographic data were similar among the groups. In group M, the number of patients reporting propofol injection pain was significantly lower than in groups F and C (both P < 0.001). No patient in group F or M experienced severe pain, whereas 24 patients (48%) had severe pain in group C (both P < 0.001).

CONCLUSIONS

This study shows that a fentanyl-propofol mixture was more effective than fentanyl pretreatment or a placebo in preventing propofol injection pain.

Prevention of injection pain due to propofol by dezocine: a comparison with lidocaine

Objectives:

The aim of this study was to investigate the efficacy of dezocine (DEZ) versus placebo control (CON) and 2% lidocaine (LID) in prevention of injection pain due to DEZ.

Materials and Methods:

A prospective randomized double-blind, placebo-CON study was conducted in 75 adults, American Society of Anesthesiologists physical status I or II, scheduled to undergo an elective surgery. A total of 25 patients were randomly assigned to one of the three groups, thus CON, group LID and group DEZ. The groups received either 2 ml of normal saline or 2 ml 2% LID or 2 mg/2 ml DEZ, respectively, as pre-treatment. Propofol was injected 1 min later. A blinded researcher assessed the patient's pain level using a four point verbal rating scale.

Results:

Less patients experienced pain due to propofol injection in the LID (40%) and DEZ (28%) groups compared with the CON (84%) group (P < 0.05). Six patients (24%) in the CON group reported severe pain during propofol injection but none in the other two groups.

Conclusion:

Pre-treatment with DEZ decreases propofol injection pain as effectively as LID.

Comparison of the preventive effects of pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine on propofol-LCT/MCT injection pain

BACKGROUND

Lidocaine has been used widely to prevent propofol injection pain. Various methods of administration exist, such as lidocaine premixed with propofol or lidocaine pretreatment using a tourniquet, but it is unclear which method of lidocaine administration is more effective for the prevention of injection pain of propofol LCT/MCT. The purpose of this study was to compare pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine to prevent injection pain of propofol-LCT/MCT.

METHODS

Patients were randomly allocated into the pretreatment group (n = 117) or the premixed group (n = 117). The pretreatment group was pretreated with 2 ml of lidocaine 2%, held with a tourniquet, before propofol-LCT/MCT injection. The premixed group was injected with a premixed solution of propofol-LCT/MCT and 2 ml of lidocaine 2%. To evaluate the incidence and severity of pain, spontaneous verbal expressions of pain, movement of hand, frowning, and moaning were recorded, and the patients were asked to recall their pain with the visual analogue score (VAS) 30 minutes after awakening from anesthesia.

RESULTS

Overall, injection pain occurred in 13.7% of the pretreatment group and 15.4% of the premixed group, without any statistical difference (P = 0.71). There was no difference in spontaneous verbal expressions of pain, movement of hand, frowning, and moaning between the two groups. The pain intensity (VAS) also showed no difference between the two groups (P = 0.49).

CONCLUSIONS

Pretreatment of lidocaine with a tourniquet showed no more benefit to prevent injection pain of propofol LCT/MCT compared to a premixed injection with lidocaine.

The optimal effect-site concentration of remifentanil to attenuate the pain caused by propofol

Background

The injection pain of propofol is a frequent and well-known adverse effect. This study was designed to determine the optimal effect-site concentration of remifentanil for minimizing injection pain during induction with propofol.

Methods

A total intravenous anesthetic technique was used for patients undergoing general anesthesia and remifentanil was pretreated to reach a certain target concentration before propofol injection. Using Dixon's up-and-down method, the degree of pain described by the patient was used to adjust the target concentration of remifentanil for the next patient. Ten success-failure curves (crossovers) were sought to find the effect-site concentration (EC) of remifentanil for minimizing injection pain of propofol.

Results

The EC of remifentanil in 50% and 95% of adult female population (EC₅₀ and EC₉₅) for minimizing injection pain of propofol were 3.09 ng/ml (95% confidence limits [CI] 2.92-3.30 ng/ml) and 3.78 ng/ml (95% CI 3.45-3.95 ng/ml), respectively. Clinically significant hemodynamic compromise or respiratory complications were not found during remifentanil infusion.

Conclusions

Maintaining 3.78 ng/ml EC of remifentanil during induction with propofol attenuate propofol injection pain without serious adverse events in female patients undergoing general anesthesia and this method may provide the patient's comfort without preparing other drugs for pain relief.

Reduction of propofol injection pain by utilizing the gate control theory

Background

Propofol is the most commonly using intravenous hypnotic for the induction and maintenance of general anesthesia. However, pain on propofol injection is a well known adverse event. Currently, acute and chronic pain can be controlled by utilizing the "gate control" theory.

Methods

Patients were randomized to receive lidocaine (0.5 mg/kg; Group L), touch on IV injection site (Group T), combination lidocaine (0.5 mg/kg) and touch on IV injection site (Group B), or normal saline (Group S) with venous occlusion for 1 minute, followed by administration of propofol (0.5 mg/kg) into the largest dorsal vein of the hand. Immediately after administering propofol, an investigator blinded to the group assignments asked the patient about pain at the injection site and assessed pain intensity using a 4-point verbal rating scale (0 = none, 1 = mild, 2 = moderate, 3 = severe).

Results

A significant decrease in the incidence of pain on propofol injection was achieved in group L (37%) and group B (23%) compared to either group T (80%) and group S (83%) (P < 0.001). But, the incidence of moderate and severe pain was significantly lower in group L (7%), group T (20%) and group B (0%) when compared to group S (53%) (P < 0.05).

Conclusions

Light touch and rubbing reduced pain, although while, they did not reduce the incidence of pain, they reduced the intensity of pain. This method might be considered as an alternative to other treatments but may be contraindicated for use with other drugs.

Sevoflurane to alleviate pain on propofol injection

PURPOSE

Since the introduction of propofol, several drugs and methods have been used to alleviate the pain on its injection. This study was designed to evaluate the effect of adding sevoflurane 3% during preoxygenation in alleviation of pain on propofol injection.

METHODS

In this randomized single-blinded study, 100 patients were randomly allocated equally into five groups: sevoflurane-lidocaine-tourniquet (SLT), sevoflurane-lidocaine (SL), lidocaine-tourniquet (LT), lidocaine (L), and sevoflurane (S). Approximately 10 min before the induction of anesthesia, midazolam 1-2 mg was administered intravenously to all patients. All patients received fentanyl 1 µg/kg as pretreatment and a full induction dose of propofol. A blinded anesthesia nurse assessed pain and hand movements throughout the injection of propofol.

RESULTS

In the SLT group, all patients (100%) were pain free and had no hand movements. There was no significant difference in pain grade or in hand movements between the L and the S groups, or between the SLT and the SL groups. However, significant differences were observed in pain grade between the SLT and the L groups as well as between the SLT and the S groups. In addition, a significant difference in hand movement was observed only between the SLT and the S groups.

CONCLUSION

The addition of 3% sevoflurane at the time of preoxygenation for 1 min along with routine use of lidocaine-tourniquet completely prevented pain upon propofol injection, whereas sevoflurane by itself provided similar analgesia to premixed lidocaine with propofol.

The effect of priming injection of different doses of remifentanil on injection pain of microemulsion propofol premixed with lidocaine

Background

The injection pain of microemulsion propofol is frequent and difficult to prevent. This study examined the prevention of pain during microemulsion propofol injection by pretreatment with different doses of remifentanil or saline, and premixing of lidocaine.

Methods

One hundred sixty ASA physical status 1-2 adult patients scheduled for elective surgery were enrolled into one of four groups (n = 40, in each). The patients received saline (group LS), remifentanil 0.3 µg/kg (group LR 0.3), remifentanil 0.5 µg/kg (group LR 0.5), or remifentanil 1.0 µg/kg (group LR 1.0), and after 90 seconds received an injection of 2 mg/kg microemulsion propofol premixed with lidocaine 40 mg. Pain was assessed on a four-point scale during microemulsion propofol injection.

Results

The incidence of microemulsion propofol-induced pain was significantly lower in the LR 0.3, LR 0.5 and LR 1.0 groups than in the LS group (37.5%, 12.5% and 10% vs 65%, respectively). The LR 0.5 and LR 1.0 groups showed significantly less frequent and intense pain than the LR 0.3 group. However, both incidence and severity of pain were not different between LR 0.5 and LR 1.0 groups.

Conclusions

The combination of remifentanil and lidocaine is effective in alleviating pain associated with a microemulsion propofol injection compared with just lidocaine. Remifentanil 0.5 µg/kg had a similar analgesic effect compared to the 1.0 µg/kg dose.

Pain reduction on injection of microemulsion propofol via combination of remifentanil and lidocaine

BACKGROUND

Microemulsion propofol produces more frequent and severe pain upon injection than lipid emulsion propofol. This study examined the analgesic effect of lidocaine-premixed microemulsion propofol in patients pretreated with remifentanil. The induction of anesthesia with this combination was compared with microemulsion propofol accompanied with either remifentanil or lidocaine.

METHODS

One hundred twenty patients aged between 20-65 years old were allocated randomly into one of three groups (n = 40, in each). The patients in the remifentanil group received remifentanil 0.5 microg/kg IV for 30 seconds before a microemulsion propofol injection. The patients in the lidocaine group received propofol 2 mg/kg premixed with 40 mg lidocaine over a 60 second period. The patients in the combination group received both remifentanil and lidocaine.

RESULTS

There was a significantly lower incidence of microemulsion propofol injection pain (severity 2 or more) in the combination group (12.5%) than in the remifentanil and lidocaine groups (90% and 65%, respectively, P < 0.05). The incidence of moderate pain disappeared completely in the combination group (0%) compared to that in the remifentanil and lidocaine group (32.5% and 20%, respectively, P < 0.05). Severe pain did not appear in any of the three groups. There were no complications on the injection site in the lidocaine alone and combination groups.

CONCLUSIONS

The combination of microemulsion propofol premixed with lidocaine after a pretreatment with remifentanil was more effective in reducing the incidence of pain upon the injection of microemulsion propofol than either treatment alone.

Preventing Pain on Injection of Propofol: A Comparison between Peripheral Ketamine Pre-Treatment and Ketamine Added to Propofol

The purpose of this study was to examine possible peripheral mechanisms for the reduction of propofol injection pain by the addition of ketamine. We hypothesised that pH changes associated with the addition of ketamine to propofol decrease propofol-induced pain on injection. We compared the efficacy of intravenous ketamine pretreatment under tourniquet with ketamine added to the propofol In the pre-treatment group, patients received ketamine 10 mg in a total volume of 1.0 ml with 0.9% saline (n=94; Group P) under tourniquet for 30 seconds before administration of propofol afler release of the tourniquet. In the mixture group, propofol 9 ml was mixed with ketamine 10 mg in 0.9% NaCl 1.0 ml (n=94, Group M). Pain was assessed with a four-point scale: 0=no pain, 1 =mild pain, 2=moderate pain, 3=severe pain at the time of propofol injection. The pH of propofol, ketamine and a range of propofol-ketamine mixtures were also measured. Forty-eight patients (51%) in Group P complained of pain on injection compared with 28 patients (30%) in Group M (P=0.005). The pH of the 1% propofol-ketamine mixture was 5.84 while 1% propofol had a pH of 7.86. Our results support pH changes as a more important cause for the decrease in propofol injection pain with the addition of ketamine to propofol than a peripheral effect of ketamine.

Prevention of propofol-induced pain in children: combination of alfentanil and lidocaine vs alfentanil or lidocaine alone

BACKGROUND

Pain from a propofol injection is a common side-effect in paediatric patients. This prospective, randomized, double-blind study evaluated the efficacy of a combined pretreatment of alfentanil with lidocaine on the incidence and severity of propofol injection pain in children.

METHODS

After obtaining parental consent, 120 paediatric patients were allocated randomly into one of the three groups (n=40, in each). The patients in the alfentanil group received alfentanil 15 microg kg(-1) 90 s before the propofol injection. The patients in the lidocaine group received propofol 3 mg kg(-1) premixed with lidocaine 0.1% over a 15 s period. The patients in the combination group received both alfentanil and lidocaine.

RESULTS

The incidence of propofol injection pain (severity 2 or more) in the combination group (2.6%) was significantly lower than that in the alfentanil and lidocaine groups (30% and 38.5%, respectively) (P=0.001 and <0.001, respectively). No patient in the combination group complained of moderate or severe pain from propofol injection.

CONCLUSIONS

Our study demonstrated that the combination treatment of two different analgesic modalities, alfentanil and lidocaine, could prevent the moderate and severe pain on propofol injection, and reduce the incidence of mild pain compared with each drug alone.

A combination of lidocaine (lignocaine) and remifentanil reduces pain during propofol injection

OBJECTIVE

Pain on injection is a well known adverse effect of propofol. The purpose of this study was to compare the analgesic effect of a lidocaine (lignocaine)/remifentanil combination compared with either lidocaine alone or remifentanil alone during propofol injection for induction of anaesthesia.

METHODS

In a randomised, double-blind, prospective trial, 129 patients were allocated to one of three groups (each n = 43) receiving lidocaine 20mg, remifentanil 0.3 microg/kg or lidocaine 20 mg plus remifentanil 0.3 microg/kg as pretreatment, followed by injection of 5 mL of 1% propofol. Pain severity was evaluated on a four-point scale.

RESULTS

Two patients (4.7%) complained of pain in the lidocaine plus remifentanil group compared with 15 (35.7%) in the lidocaine alone group and 18 (42.9%) in the remifentanil alone group (p < 0.001). There was no significant difference in the incidence of injection pain between the lidocaine alone and remifentanil alone groups (p = 0.21).

CONCLUSION

Pretreatment with a combination of lidocaine and remifentanil is more effective than either pretreatment alone in reducing pain on injection of propofol.