Ondansetron Pretreatment to Alleviate Pain on Propofol Injection: A Randomized, Controlled, Double-Blinded Study

Evaluation of Peripheral Versus Central Route of Ondansetron as Pretreatment to Prevent Pain on the Injection of Propofol: A Randomized Controlled Study

Objective

We evaluated whether systemic ondansetron was also useful in the attenuation of propofol injection pain similar to ondansetron pretreatment.

Methods

Eighty patients were enrolled. Patients in group S received ondansetron 4 mg in saline in the right hand followed 30 min later by 5 mL saline in the left hand along with venous occlusion. Group L patients received 4 mL of saline in the right hand followed by 5 mL 4 mg ondansetron in the left hand after 30 min. Two minutes later the occlusion was released. Patients received one-fourth of the calculated total dose of propofol, and their level of pain was graded on a scale of 0 to 3, with 0 denoting no discomfort. Mean blood pressure and heart rates were also recorded. Continuous variables were checked for normality using Shapiro-Wilks test. Normal continuous variables were expressed as mean standard deviation and non-normal continuous variables were expressed as median interquartile range. T-test for the difference in the mean and paired test were used for normally distributed continuous variable whereas Mann-Whitney U test-Wilcoxon test and sign test were used for non-normally distributed variables. Repeated measure analysis of variance was used for a variable measured over different periods of time to control for the baseline effect on subsequent measures.

Results

Our results demonstrated that both systemic administration 30 min before and local venous pretreatment with ondansetron were equally beneficial in reducing pain during propofol injection.

Conclusion

A systemic administration of ondansetron may play a role in the attenuation of propofol injection pain.

Efficacy of different doses of lidocaine in the prevention of pain due to propofol injection: a randomized, open-label trial in 120 patients

BACKGROUND

The incidence of pain due to propofol injection is high, but the most efficacious method of preventing this pain has not been identified.

OBJECTIVE

The aim of this study was to investigate the efficacy of lidocaine, at different doses and schedules, on propofol injection pain.

METHODS

In this open-label study, conducted at the Department of Anaesthesiology, Erciyes University Gevher Nesibe Hospital (Kayseri, Turkey), patients with American Society of Anesthesiologists Patient Acuity Classification I-II (ASA I-II) (ie, patients with absent [I] or mild [II] underlying systemic disease) aged 18 to 60 years undergoing various types of surgery were eligible. Patients were randomized to 1 of 4 treatment groups: group 1 received propofol; group 2, a combination of propofol plus lidocaine 10 mg; group 3, lidocaine 10 mg 30 seconds before propofol administration; and group 4, lidocaine 1 mg/kg 30 seconds before propofol administration (all drugs were administered intravenously). After cessation of the standard replacement fluid infusion (isotonic saline), propofol was given at a rate of 2 mL every 5 seconds until a dose of 2 mg/kg was reached. The patients were asked to rate their pain according to the following scale: 0 = none, 1 = mild, 2 = moderate, and 3 = severe.

RESULTS

A total of 120 patients (61 men, 59 women; mean [SD] age, 38.7 [8.9] years) were enrolled in the study (n = 30 patients in each group). The incidence of injection pain in groups 2 and 4 was significantly lower than that in groups 1 and 3 (all P<0.05), but no significant difference in the incidence of pain was found between groups 1 and 3. The incidence of pain in group 2 was significantly lower than that in group 4 (P<0.05).

CONCLUSIONS

In this study population, the addition of 10 mg of lidocaine to propofol 2 mg/kg, or the administration of 1 mg/kg of lidocaine 30 seconds before the administration of propofol 2 mg/kg, effectively decreased pain caused by propofol injection. Furthermore, a lower dose of lidocaine could be used. Based on our results, we suggest mixing propofol with 10 mg of lidocaine to decrease pain due to propofol injection during anesthesia induction.

The anti-inflammatory effects of the 5-HT₃ receptor antagonist tropisetron are mediated by the inhibition of p38 MAPK activation in primary human monocytes

BACKGROUND

There is evidence from human and animal research that 5-hydroxytryptamine (5-HT) 3 receptor antagonists, particularly tropisetron, exert analgesic and anti-inflammatory activity. We have demonstrated that tropisetron inhibited lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF)alpha and interleukin-(IL-)1beta release in primary human monocytes. The underlying mechanisms of these effects have not been investigated in detail so far.

METHODS

The molecular mechanisms of the anti-inflammatory effects of tropisetron were investigated in human primary monocytes in vitro by studying IL-1beta and TNFalpha mRNA levels by PCR and reporter gene assay and by elucidating the phosphorylation of p38 mitogen activated kinase (MAPK) by Western blot.

RESULTS

The steady state levels of IL-1beta and TNFalpha mRNA in LPS-activated human peripheral monocytes and the transcriptional activity of the TNFalpha promoter were not inhibited by tropisetron, suggesting that the inhibitory activity of this 5-HT₃ receptor antagonist takes place at the post-transcriptional level. Additionally, we found that tropisetron prevents the phosphorylation and thus activation of the p38 MAPK, which is involved in post-transcriptional regulation of various cytokines.

CONCLUSION

Our data indicate that the anti-inflammatory effects of the 5-HT₃ receptor antagonist tropisetron, as shown in vivo, are possibly mediated by a selective inhibition of pro-inflammatory cytokines at the post-transcriptional level. 5-HT₃ receptor antagonists are therefore a new and promising therapeutic option. New and more selective--in respect to the 5-HT₃ subtypes--5-HT₃R antagonists might be a future perspective in the pharmacological treatment of inflammatory diseases.

Influence of aging on lidocaine requirements for pain on injection of propofol

STUDY OBJECTIVE

To evaluate the influence of aging on lidocaine requirements for propofol-induced pain on injection.

DESIGN

Prospective, randomized, double-blind, placebo-controlled study.

SETTING

The study was undertaken at a University hospital.

PATIENTS

160 ASA physical status I and II adult patients scheduled for elective surgery with general anesthesia.

INTERVENTIONS

Patients received placebo (saline) or lidocaine intravenously at three different doses (10, 20, or 40 mg), with venous occlusion for two minutes, followed by injection of propofol 0.5 mg/kg into a dorsal hand vein.

MEASUREMENT AND MAIN RESULTS

Pain during injection of propofol was evaluated. For young patients, the frequency of propofol-induced pain was 70% in patients receiving lidocaine 10 mg (P = not significant); 50% in those receiving lidocaine 20 mg (P = not significant); and 30% in those receiving lidocaine 40 mg (P < 0.05), compared with placebo (80%). For elderly patients, 15 patients (75%) complained of pain in the placebo group, compared with 13 (65%) in the lidocaine 10 mg group (P = not significant); 5 (25%) in the lidocaine 20 mg group (P < 0.05); and 4 (20%) in the lidocaine 40 mg group (P < 0.05).

CONCLUSIONS

A lidocaine dose of 40 mg for young patients and 20 mg for old patients, with venous occlusion for two minutes, is sufficient to reduce pain on injection of propofol.

Influence of age on flurbiprofen axetil requirements for preventing pain on injection of propofol in Japanese adult surgical patients: a prospective, randomized, double-blind, vehicle-controlled, parallel-group, dose-ranging study

BACKGROUND

Pain on injection is a recognized adverse event (AE) of propofol administration for the induction of general anesthesia. Preceded by venous occlusion, flurbiprofen axetil, a prodrug of the NSAID flurbiprofen, has been associated with a reduction in pain induced by propofol injection. A review of the literature determined that no published data were available on the influence of age on the requirements for flurbiprofen axetil dose.

OBJECTIVE

This study was undertaken to examine the influence of age on flurbiprofen axetil requirements for the treatment of propofol-induced pain on injection in Japanese adult surgical patients.

METHODS

This prospective, randomized, double-blind, vehicle-controlled, parallel-group, dose-ranging study was conducted at the Department of Anesthesiology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan. Young (age 20-40 years) and older (age 60-80 years) Japanese patients scheduled for various types of surgery (eg, cholecystectomy) were eligible. Patients were randomized to receive flurbiprofen axetil at 1 of 2 doses (25 or 50 mg, regardless of body weight) or inactive vehicle (saline), preceded by manual venous occlusion with a rubber tourniquet for 2 minutes and followed by the infusion of the first 25% of calculated propofol dose (0.5 mg/kg at room temperature, 23 degrees C) into the largest dorsal vein of the hand through a 20-G IV cannula (without local anesthesia), followed by the release of the occlusion and delivery of propofol 2 mg/kg. An investigator blinded to treatment questioned each patient about pain intensity during propofol injection which was assessed using a verbal rating scale: 0 = none; 1 = mild; 2 = moderate; and 3 = severe. The overall prevalence of pain was calculated in each group. AEs at the injection site (pain, edema, wheal, inflammation) were assessed by the study investigator for 24 hours after surgery using spontaneous reporting and patient interview.

RESULTS

A total of 150 patients, 75 young adults (38 men, 37 women; mean [SD] age, 31 [5] years; mean [SD] height, 163 [7] cm; mean [SD] body weight, 58 [9] kg) and 75 older adults (38 men, 37 women; mean [SD] age, 70 [6] years; mean [SD] height, 154 [8] cm; mean [SD] body weight, 53 [10] kg), were enrolled. Each treatment group comprised 25 patients. No differences in demographic characteristics were observed among the 3 study groups. In young patients, the overall prevalence of propofol-induced pain was significantly lower in patients who received flurbiprofen axetil 50 mg (12 [48%]) compared with that in patients who received flurbiprofen axetil 25 mg (20 [80%]) or vehicle (22 [88%]) (P < 0.05 and P < 0.01, respectively). The median pain intensity score was significantly lower in patients who received flurbiprofen axetil 50 mg (0) compared with that in patients who received flurbiprofen axetil 25 mg (1) or vehicle (2) (P < 0.05 and P < 0.01, respectively). In older patients, the overall prevalences of pain on propofol injection were 9 (36%) in the flurbiprofen axetil 50-mg group and 11 (44%) in the flurbiprofen axetil 25-mg group compared with 21 (84%) in the vehicle group (both, P < 0.01). The median pain score was significantly lower in patients who received flurbiprofen 50 mg (0) or 25 mg (0) than in those who received vehicle (1) (both, P < 0.01). All treatments were well tolerated.

CONCLUSIONS

In this small clinical trial in Japanese surgical patients undergoing general anesthesia, flurbiprofen axetil requirements for the reduction of pain during injection of propofol were found to be 50 mg in young adults (age 20-40 years) and 25 or 50 mg in older adults (age 60-80 years), regardless of weight, preceded by venous occlusion for 2 minutes.

Inadvertent epidural injection of ondansetron

A case of accidental epidural injection of ondansetron in a parturient is reported. No neurologic sequela resulted from the mistaken epidural injection. Vigilance is essential for minimizing the risk of epidural injections.

The effects of alfentanil or remifentanil pretreatment on propofol injection pain

STUDY OBJECTIVE

To compare the efficacy of alfentanil, remifentanil, and saline in minimizing the propofol injection pain.

DESIGN

Randomized, double-blind study.

SETTING

University hospital.

PATIENTS

175 ASA physical status I and II, adult female patients undergoing minor gynecological procedures with general anesthesia.

INTERVENTIONS

Unpremedicated patients were randomly allocated to one of four groups. Patients received 2 mL (1 mg) of alfentanil (n=43), 2 mL of remifentanil 0.01 mg (n = 43), 2 mL of remifentanil 0.02 mg (n=45), or 2 mL of saline (n=44) 30 seconds prior to administration 5 mL of propofol 1%.

MEASUREMENTS

Patients were asked whether they had pain due to propofol injection. Their pain scores were evaluated with a Visual Analogue Scale. In the Postanesthesia Care Unit, frequency of postoperative nausea, vomiting, hypotension, and flushing were all determined.

MAIN RESULT

The remifentanil and alfentanil groups showed significantly less frequency and severity of pain than the saline group (p <0.05). When the alfentanil group was compared with the remifentanil groups, significant differences in pain relief associated with injection of propofol (p <0.001) were noted. Remifentanil 0.02 mg relieved pain associated with injection of propofol more effectively than remifentanil 0.01 mg (p <0.001).

CONCLUSIONS

The remifentanil and alfentanil groups showed significantly less frequency and severity of pain than did the saline group. Remifentanil was effective in preventing propofol injection pain, and should be used at a dose of at least 0.02 mg for this purpose. Remifentanil may be an alternative drug for prevention of propofol injection pain.

Current experience with 5-HT3 receptor antagonists in fibromyalgia

Pain is perceived, transmitted, processed and modulated within an extensive network of neurotransmitters and hormones. Despite increasing knowledge about the biologic principles, even on the molecular level, the more we learn about the precise mechanisms of their interactions the more questions arise. It is also pertinent to remember that clinical scientists studying pain modulating pharmacologic agents always have to consider possible placebo effects [57-61]. Most of our knowledge regarding the function of neurotransmitter systems in the CNS has been provided by animal studies. Thus we cannot be sure that they have exactly parallel counterparts in humans. For instance, animal studies suggest an inverse relationship between brain and spinal cord concentrations of substance P. If these observations are converted to an interpretation of human fibromyalgia, low brain-tissue levels of both serotonin and substance P should be expected, while spinal cord serotonin concentrations would be low and spinal cord substance P would be high [1]. There is good evidence that 5-HT, its receptors, and their interactions with other neurotransmitters are essential for nociception and antinociception. The activities of 5-HT receptors can be studied by agonist and in humans especially by antagonist use. But even with a direct spinal application of selective agonists and antagonists, observations may still be confounded by (1) dose, as there can be a dose-dependent activation of different receptor subtypes; (2) type of nociceptive tests (e.g., thermal versus pressure versus chemical models), which may have differences in the way they are regulated; and (3) influences due to effects on temperature, blood flow or motor function. With this potential for variability, it is perhaps not surprising that there is some variability in the results of studies reporting on the effects of various 5-HT agonists and antagonists on nociceptive transmission within the spinal cord [62]. For instance, different 5-HT3 receptor densities could exist in various neuronal systems, one density type being completely inhibited at low concentrations, and the others only at higher concentrations of 5-HT3 receptor antagonists, thus resulting in contrary effects. Finally, the "endogeneous 5-HT tone" may greatly influence agonist and antagonist action. Considering this complexity of serotonin-mediated reactions, it is not surprising that treatment of pain by 5-HT3 receptor antagonists appears to yield inconsistent results. As fibromyalgia is now regarded as a pain amplification syndrome with a broad variety of additional nonpain symptoms, the interrelations are complicated even more. Fibromyalgia associated symptoms (e.g., fatigue, insomnia, and irritable bowel syndrome) can be modulated by 5-HT3 receptor antagonists. From the data evaluated so far, there is evidence that 5-HT3 receptor antagonists provide significant benefit in some fibromyalgia patients. In our practice, the data justify a careful application in clinical use according to the study results. The dosage, route of application, long term adverse reactions and duration of therapy still need to be studied in greater detail. Recently reported adverse events from therapy of irritable bowel syndrome with alosetron [63-67] provide a note for caution before hastily using 5-HT3 receptor antagonists without more studies. One can surmise that, much as the biochemistry of depression has been elucidated by the development of the SSRIs, a greater understanding of the role of 5-HT3 receptor antagonists in treating fibromyalgia patients may provide some insights into disease mechanisms of this enigmatic disorder.