Prevention of Pain on Injection with Propofol: A Quantitative Systematic Review

Drug-drug interaction study of ciprofol and sodium divalproex: Pharmacokinetics, pharmacodynamics, and safety in healthy Chinese subjects

Ciprofol (also known as HSK3486) is a promising intravenous anesthetic candidate derived from propofol and independently developed by Haisco Pharmaceutical Group Co., Ltd. (Chengdu, China). Compared with propofol, ciprofol has the potential to reduce the dose required and the associated risks. Ciprofol is extensively metabolized in vivo, and its interaction with other concurrently administered drugs during clinical application is worthy of attention. Therefore, an open-label, two-stage sequential study was performed in healthy subjects who received either a single administration of ciprofol injection or ciprofol injection after oral administration of sodium divalproex. The aim of the study was to evaluate the effects of sodium divalproex on ciprofol with respect to pharmacokinetics, pharmacodynamics, and safety, thus providing a basis for the rational clinical use of ciprofol and sodium divalproex.

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.

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).

Comparison of ciprofol (HSK3486) versus propofol for the induction of deep sedation during gastroscopy and colonoscopy procedures: A multi-centre, non-inferiority, randomized, controlled phase 3 clinical trial

Ciprofol is a propofol analogue with improved pharmacokinetic properties. A multi‐centre, non‐inferiority trial was conducted to compare the deep sedation properties of ciprofol and propofol with a non‐inferiority margin of 8% in patients undergoing gastroscopy and colonoscopy. In total, 289 patients were randomly allocated for surgery (259 colonoscopy and 30 gastroscopy) at a 1:1 ratio to be given intravenous injections of ciprofol (0.4 mg/kg) or propofol (1.5 mg/kg). The primary outcome was the success rate of colonoscopy defined as colonoscopy completion with no need for an alternative sedative or >5 ciprofol or propofol top up doses within any 15‐min time period. The success rate of colonoscopy was 100% in the ciprofol group vs. 99.2% in the propofol group (mean difference 0.8%, 95% CI: −2.2% to 4.2%). Except for the gastrointestinal lesions found during the gastroscopy and colonoscopy procedures, the occurrence rates of adverse drug reactions in the ciprofol and propofol groups were 31.3% and 62.8%, respectively (P < 0.001). Pain on injection was less common in the ciprofol group (4.9% vs. 52.4%, P < 0.001). The outcomes demonstrated that ciprofol was non‐inferior to propofol with regard to successful sedation for gastroscopy or colonoscopy procedures and no obvious important adverse events occurred.

Clinical Study on the Combination of Transcutaneous Electrical Acupoint Stimulation and Lidocaine for Preventing Propofol Injection Pain

Purpose

Propofol is a widely used intravenous anesthetic in clinical practice. Lidocaine pretreatment is currently the most commonly used method to reduce the pain of propofol injection. However, propofol injection pain has not been eliminated and its incidence remains high. Transcutaneous electrical acupoint stimulation is a green therapy that combines transcutaneous electrical nerve stimulation therapy with the traditional acupuncture therapy of our motherland. This study investigated the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) combined with lidocaine in preventing propofol injection pain and determined whether it can reduce postoperative complications and promote rapid postoperative recovery of patients.

Patients and Methods

A total of 220 women scheduled to undergo hysteroscopic surgery were enrolled in the study. The included patients were randomly divided into four groups of 55 patients each: normal saline group (group K), lidocaine group (group L), TEAS group (group T), and lidocaine + TEAS group (group L + T). Patients in group K received 2 mL saline (0.9% NaCl) pre-injection before anesthesia induction. Group L received 40 mg lidocaine pre-injection (2 mL of 2% lidocaine) before anesthesia induction. Group T received 30 min of transcutaneous electrical stimulation at bilateral election Hegu, Neiguan, and 2 mL saline pre-injections before anesthesia induction. Group L + T received TEAS and lidocaine pre-injection.

Results

The VAS scores and the four-point verbal rating scale of propofol injection were significantly different among the four groups. The prevalence of nausea, vomiting, abdominal pain, and abdominal distension after surgery among the four groups were statistically different. The bleeding days after surgery were significantly different among the four groups.

Conclusion

TEAS combined with lidocaine pre-injection reduced the incidence of propofol injection pain and significantly reduced patients’ pain levels compared with single lidocaine pre-injection. TEAS can also reduce the incidence of postoperative nausea and vomiting, abdominal pain, and abdominal distension, shorten postoperative bleeding days, and accelerate the postoperative recovery of patients.

Efficacy and Safety of HSK3486 for Anesthesia/Sedation in Patients Undergoing Fiberoptic Bronchoscopy: A Multicenter, Double-Blind, Propofol-Controlled, Randomized, Phase 3 Study

BACKGROUND

Fiberoptic bronchoscopy is a complex procedure with the need for sufficient patient anesthesia/sedation while maintaining safety. This trial aimed to evaluate the efficacy, safety, and pharmacokinetics of HSK3486 during fiberoptic bronchoscopy.

METHODS

This multicenter, double-blind, randomized, non-inferiority, parallel-group phase 3 trial was conducted in patients who underwent fiberoptic bronchoscopy. Patients randomly received HSK3486 0.4 mg/kg (N = 134) or propofol 2.0 mg/kg (N = 133). The primary efficacy endpoint was the successful rate of fiberoptic bronchoscopy, and secondary efficacy endpoints included successful induction of anesthesia/sedation, duration, time to being fully alert, and time to patient discharge. Safety assessments and drug concentrations were also measured.

RESULTS

A total of 267 patients completed fiberoptic bronchoscopy, with a success rate of 100% and a 95% confidence interval of - 2.8 to 2.8% for the difference between the groups, which met the predesigned criteria of > - 8%, confirming the non-inferiority of anesthesia/sedation produced by HSK3486 compared to propofol. Among the secondary efficacy endpoints, only time to full alertness (median 8.50 vs. 6.00 min, P = 0.012) and time to discharge (median 13.00 vs. 9.87 min, P = 0.002) were slightly longer in the HSK3486 group. The incidence of adverse events was significant lower in the HSK3486 group (52.6 vs. 76.5%, P < 0.001) mainly because of less pain on injection (4.4 vs. 39.4%, P < 0.001) compared to the propofol group. HSK3486 had a similar terminal elimination half-life as propofol.

CONCLUSIONS

HSK3486 exhibited non-inferiority anesthesia/sedation compared to propofol in patients undergoing fiberoptic bronchoscopy, and had a good safety profile with a lower incidence of pain on injection.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT04111159, registered on 1 October 2019.

Factors Associated with Occurrence of Atelectasis during Sedation for Imaging in Pediatric Patients: A Retrospective Single Center Cohort Study

Sedation can induce atelectasis which may cause suboptimal image quality. This study aimed to identify factors associated with the occurrence of atelectasis during sedation for imaging in pediatric patients. Patients < 18 years who had undergone whole-body magnetic resonance imaging (MRI) under sedation with propofol or dexmedetomidine were included in this study. The development of atelectasis was visually and quantitatively assessed by coronal short tau inversion recovery images of the thoracic level. Multivariable logistic regression was performed to identify the independent factors associated with the development of atelectasis. Ninety-one patients were included in the analysis. In the multivariable analysis, administration of supplemental oxygen was the only factor significantly associated with the occurrence of atelectasis (adjusted odds ratio, 4.84; 95% confidence interval, 1.48-15.83; p = 0.009). Univariable analysis showed that the use of dexmedetomidine was associated with a lower incidence of atelectasis; however, this could not be verified in the multivariable analysis. Among the pediatric patients who had undergone imaging under sedation, additional oxygen supplementation was the only independent factor associated with atelectasis occurrence. A prospective clinical trial is required to identify the cause-effect relationship between oxygen administration and occurrence of atelectasis during sedation.

Pain Intensity at Injection Site during Esophagogastroduodenoscopy Using Long- and Medium-Chain versus Long-Chain Triglyceride Propofol: A Randomized Controlled Double-Blind Study

Background/Aims

The intensities of injection pain resulting from the use of long- and medium-chain triglyceride (LCT/MCT) propofol and conventional LCT propofol during esophagogastroduodenoscopy (EGD) have yet to be compared. We aimed to determine the pain intensity caused by different formulations of propofol and to evaluate the formulation that would be preferred by patients as a sedative agent during their next procedure.

Methods

This study was a single-center, randomized, controlled, and double-blind trial. Pain intensity was estimated 30 seconds after propofol injection by an examiner who was blinded to the group assignment using a numeric (0-10) pain rating scale (NPRS). After 1 week, the patients were asked whether they could recall the pain and were willing to receive the same agent for their next EGD.

Results

One hundred twenty-nine patients were randomly assigned to LCT/MCT or LCT group. Although there was no significant difference in pain incidence between the LCT/MCT and LCT groups (52.9% vs 65.6%, p=0.156), the pain intensity was significantly lower in the LCT/MCT group (NPRS median [interquartile range]; 1 (0-2) vs 2 (0-5), p=0.005). After 1 week, fewer patients in the LCT/MCT group recalled the pain (19.1% vs 63.9%, p<0.001) and more patients in the LCT/MCT group were more willing to use the same agent for their next procedure (86.8% vs 72.1%, p=0.048) than in the LCT group.

Conclusions

LCT/MCT propofol significantly reduced injection pain intensity compared to LCT propofol during EGD and preferred by patients as a sedative agent during their next EGD.

Median Effective Dose of Lidocaine for the Prevention of Pain Caused by the Injection of Propofol Formulated with Medium- and Long-Chain Triglycerides Based on Lean Body Weight

OBJECTIVE

To determine the median effective dose (ED50) of prophylactic intravenous lidocaine for the prevention of propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) emulsion injection pain.

DESIGN

Prospective trial, Dixon up-and-down sequential method.

SETTING

Operating room of a single hospital.

PATIENTS

Thirty patients aged 18-65 years with American Society of Anesthesiologists (ASA) status I or II who were scheduled for elective surgery under general anesthesia (GA) were included.

INTERVENTIONS

The initial dose of prophylactic lidocaine before propofol MCT/LCT emulsion injection was set at 0.5 mg/kg lean body weight (LBW). The lidocaine dose was adjusted according to the degree of patients' injection pain using the Dixon up-and-down sequential method.

MEASUREMENTS

The ED50 and 95% confidence intervals (CIs) of lidocaine were calculated using the Dixon-Massey formula. Vital signs and adverse effects were recorded. In the postanesthesia care unit (PACU), patients were asked if they recalled feeling any injection pain with visual analog scale (VAS) evaluation.

RESULTS

The ED50 of lidocaine for the prevention of propofol MCT/LCT emulsion injection pain was 0.306 mg/kg LBW (95% CI, 0.262-0.357 mg/kg LBW). No adverse reactions to lidocaine occurred. In the PACU, 90.9% of patients who experienced injection pain recalled this pain (VAS score, 2.8±1.8).

CONCLUSIONS

Prophylactic intravenous lidocaine (0.306 mg/kg LBW) effectively prevented propofol MCT/LCT emulsion injection pain in 50% of patients scheduled for elective surgery under GA with no adverse reaction occurring.

Efficient and flexible synthesis of new photoactivatable propofol analogs

Propofol is a widely used general anesthetic, which acts by binding to and modulating several neuronal ion channels. We describe the synthesis of photoactivatable propofol analogs functionalized with an alkyne handle for bioorthogonal chemistry. Such tools are useful for detecting and isolating photolabeled proteins. We designed expedient and flexible synthetic routes to three new diazirine-based crosslinkable propofol derivatives, two of which have alkyne handles. As a proof of principle, we show that these compounds activate heterologously expressed Transient Receptor Potential Ankyrin 1 (TRPA1), a key ion channel of the pain pathway, with a similar potency as propofol in fluorescence-based functional assays. This work demonstrates that installation of the crosslinkable and clickable group on a short nonpolar spacer at the para position of propofol does not affect TRPA1 activation, supporting the utility of these chemical tools in identifying and characterizing potentially druggable binding sites in propofol-interacting proteins.

Clinical therapeutic effects of lidocaine combination with flurbiprofen axetil for reducing propofol-induced pain in adults: A protocol for systematic review and meta-analysis

BACKGROUND

Pain on injection is a well-recognized adverse event of propofol administration for the stimulation of general anesthesia. Pre-treatment with lidocaine or flurbiprofen axetil has proven to be effectual in the reduction propofol-induced pain in adults. Nonetheless, only few studies have evaluated the clinical therapeutic effects of lidocaine combination with flurbiprofen axetil to prevent pain on injection of propofol. The current study aims to evaluate the clinical therapeutic effects of lidocaine combination with flurbiprofen axetil to reduce pain on injection of propofol among adult patients.

METHODS

The literature search will be conducted from their inception to November 2020 from MEDLINE, EMBASE, Web of Science, and Cochrane Library databases without date or geographical restrictions. However, language will be restricted to publications in English and Chinese. Two authors will independently screen abstracts and titles of all papers to determine whether to include or exclude them. The authors will also study characteristic and outcomes of data extraction and carry out risk of bias assessment. We plan to use either a fixed-effects or random-effects model to estimate the risk ratios (RR) or mean difference (MD) or standardized mean difference (SMD) together with 95% confidence interval (CI).

RESULTS

This study will provide high-quality evidence for the clinical therapeutic effects of lidocaine combination with flurbiprofen axetil for reducing pain on injection of propofol in adult patients.

CONCLUSION

This study will summarize current evidence for the management of pain on injection of propofol in adult patients and provide guidance for both intervention and future research.

ETHICS AND DISSEMINATION

Since no data collection will be involved, there is no need for an ethics approval.

REGISTRATION NUMBER

November 17, 2020.osf.io/72tpj/. (https://osf.io/72tpj/).

De-mystifying the "Mixifusor"

Total intravenous anesthesia (TIVA) using a mixture of propofol and remifentanil in the same syringe has become an accepted technique in Pediatric Anesthesia. A survey by a group of respected UK anesthetists demonstrated a low incidence of serious complications, related to the pharmacology and dose of the drugs. However, a current guideline for the safe use of TIVA recommends against this practice. Pharmaceutical concerns include the physical stability of the emulsion when remifentanil is mixed with propofol; changes in drug concentration over time; nonuniform mixing of propofol and remifentanil; the risk of bacterial contamination; and the potential for drug administration errors. Propofol and remifentanil have markedly different pharmacokinetic profiles. When remifentanil is mixed with propofol and delivered as a target-controlled infusion (TCI) of propofol, remifentanil delivery is not target-controlled but passively follows the variable infusion rates calculated by the syringe driver to deliver predicted plasma or effect-site concentrations of propofol. The pharmacokinetic consequences can be illustrated using pharmacokinetic modeling similar to that used in TCI pumps. The clinical consequences reflect the dose-dependent pharmacodynamics of remifentanil. Increasing the target propofol concentration produces a rapid increase and peak in remifentanil concentration that risks apnea, bradycardia, and hypotension, especially with higher concentrations of remifentanil. The faster decline in remifentanil concentration with falling propofol concentrations risks inadequate narcosis and unwanted responses to surgical stimuli. Remifentanil delivery is inflexible and dosing cannot be adjusted to the clinical need and responses of individual patients. The medicolegal considerations are stark. In UK and EU Law, mixing propofol and remifentanil creates a new, unlicensed drug and the person mixing takes on the responsibilities of manufacturer. If a patient receiving anesthesia in the form of a mixed propofol-remifentanil infusion suffered a critical incident or actual harm, the clinician's practice may come under scrutiny and criticism, potentially involving a legal challenge and the Medical Regulator.

Drug selection for sedation and general anesthesia in children undergoing ambulatory magnetic resonance imaging

The demand for drug-induced sedation for magnetic resonance imaging (MRI) scans have substantially increased in response to increases in MRI utilization and growing interest in anxiety in children. Understanding the pharmacologic options for deep sedation and general anesthesia in an MRI environment is essential to achieve immobility for the successful completion of the procedure and ensure rapid and safe discharge of children undergoing ambulatory MRI. For painless diagnostic MRI, a single sedative/anesthetic agent without analgesia is safer than a combination of multiple sedatives. The traditional drugs, such as chloral hydrate, pentobarbital, midazolam, and ketamine, are still used due to the ease of administration despite low sedation success rate, prolonged recovery, and significant adverse events. Currently, dexmedetomidine, with respiratory drive preservation, and propofol, with high effectiveness and rapid recovery, are preferred for children undergoing ambulatory MRI. General anesthesia using propofol or sevoflurane can also provide predictable rapid time to readiness and scan times in infant or children with comorbidities. The selection of appropriate drugs as well as sufficient monitoring equipment are vital for effective and safe sedation and anesthesia for ambulatory pediatric MRI.

Acceptability of intravenous propofol sedation for adolescent dental care

PURPOSE

Propofol is an intravenous anaesthetic agent commonly utilised in general anaesthesia, however in sub-anaesthetic concentrations can be utilised to provide sedation through automated dosing of target-controlled infusion (TCI). TCI has been shown to provide accurate and stable predicted plasma and effect-site concentrations of propofol. A four-part mixed-method prospective study was undertaken to evaluate the safety and patient acceptability of intravenous propofol sedation in adolescent patients requiring dental care. There is a paucity in the literature on patient-reported outcomes and patient safety in the management of adolescent patients for dental treatment.

METHODS

Demographics were recorded including age, gender, ASA Classification and Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) completed pre-operatively. Behaviour ratings of the Frankl and Houpt scales were recorded followed by post-operative questionnaire and telephone consultation. Consultation was completed following the procedure to determine patient satisfaction, memory of the procedure and any reported side effects of treatment. Qualitative thematic analysis was utilised.

RESULTS

55 patients were recruited for the study, of which 49 (mean age 14.67 years) completed the sedation study and were treated safely with no post-operative complications. The mean lowest oxygen saturation was 98.12% SpO₂ (SD 2.6). Thematic analysis demonstrated positive patient-reported outcomes to IV sedation.

CONCLUSION

Propofol TCI sedation is an effective treatment modality for the management of dentally anxious adolescents as a safe alternative to general anaesthesia, allowing the opportunity for increased provision of treatment per visit on those patients with a high dental need. Further randomised controlled trials comparing propofol TCI to other pharmacological managements are required.

The propofol-sparing effect of intravenous lidocaine in elderly patients undergoing colonoscopy: a randomized, double-blinded, controlled study

Background

Propofol provides a prominent sedation effect in colonoscopy. However, anesthesia and sedation induced with propofol in the elderly might result in cardiopulmonary complications, especially when it is combined with opoids in the regimen. This study aimed to test the hypothesis that the addition of intravenous lidocaine to propofol-based sedation could decrease the overall propofol requirement in elderly patients during colonoscopy while the procedural sedation satisfaction and the hemodynamic stability were not compromised.

Methods

Ninety-two patients undergoing colonoscopy were randomly enrolled into lidocaine+propofol (L + P) group or normal saline+propofol (NS + P) groups. Subjects received intravenous bolus of 1.5 mg/kg lidocaine followed by 4 mg kg^− 1 h^− 1 lidocaine continuous infusion in L + P group or equivalent volumes of normal saline for boluses and infusion in NS + P group. Anesthesia was induced with 2.5 μg sufentanil followed by injection of 1.2 mg kg^− 1 propofol in all patients. A single supplemental bolus of 0.6 mg kg^− 1 propofol was administered whenever MOAA/S score > 1 or had body movement during the colonoscopy. The recorded primary endpoints included: the total amount of propofol administered during entire procedure, the supplemental amount of propofol after induction, and the frequencies of boluses of supplemental propofol.

Results

A total of 79 patients were included in the final analysis. Compared with NS + P group, the total amounts of propofol (induction plus supplemental) were no significant differences in L + P group; however, the required supplemental propofol was less (69.9 ± 39.2 mg vs. 51.5 ± 38.6 mg) (P = 0.039); the average frequencies of boluses of supplemental propofol given after induction were lower (2.1 ± 1.1 vs. 1.4 ± 0.9) (P = 0.003); the calculated “unit propofol” infusion rate was lower (0.18 ± 0.05 vs. 0.14 ± 0.04 mg kg^− 1 min^− 1) (P = 0.002).

Conclusions

The addition of intravenous lidocaine to propofol-based sedation resulted in a remarked reduction of supplemental propofol in the elderly during colonoscopy.

Trial registration

The present clinical trial was registered at http://www.chictr.org.cn on 11th March 2019 (registration No. ChiCTR1900021818).

Effect-site concentration of remifentanil for preventing propofol injection pain during induction of balanced anesthesia

Background

Despite various strategies designed for preventing pain from propofol injection, it is still common and distressing to the patients. The purpose of the present study was to investigate the adequate effect-site concentration (Ce) of remifentanil to prevent pain due to propofol injection.

Methods

A total of 160 adults scheduled for elective surgery were randomly assigned to one of four groups receiving normal saline (group S) or remifentanil at a Ce of 2 (group R2), 3 (group R3), or 4 ng/ml (group R4), administered via target-controlled infusion, followed by the injection of 2 mg/kg of propofol (delivered with 1% lipid propofol). The severity and incidence of injection pain were assessed on a four-point scale.

Results

The incidence of propofol injection pain was significantly lower in group R2, R3, or R4 than in group S (30%, 5%, or 2.5% vs. 70%, respectively). Moreover, the intensity of the pain was lesser in group R2, R3, or R4 than in group S. However, the incidence or severity of injection was not different between groups R3 and R4.

Conclusions

During the induction of balanced anesthesia using propofol injection, pretreatment with remifentanil at a target Ce of 3 ng/ml effectively reduced propofol injection pain in adults.

Comparison of Fentanyl, Remifentanil, Sufentanil and Alfentanil in Combination with Propofol for General Anesthesia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Opioid analgesics are commonly used along with propofol during general anesthesia. Due to the dearth of data on the quality of anesthesia achieved with this combination, the present meta-analysis was carried out.

METHODS

Electronic databases were searched for appropriate studies using a suitable search strategy. Randomized clinical trials comparing the combination of remifentanil/sufentanil/alfentanil with propofol with fentanyl and propofol, were included. The outcome measures were as follows: total propofol dose to achieve the desired general anesthesia; time of onset and duration of general anesthesia; depth of general anesthesia; and recovery time (time for eye-opening and time taken for extubation). Risk of bias was assessed and Forest plots were generated for eligible outcomes. The weighted mean difference [95% confidence intervals] was used as the effect estimate.

RESULTS

Fourteen studies were included in the systematic review and 13 were included in the metaanalysis. Statistically significant differences were observed for remifentanil in comparison to fentanyl when combined with propofol: Propofol dose (in mg) -76.18 [-94.72, -57.64]; time of onset of anesthesia (min) -0.44 [-0.74, -0.15]; time taken for eye-opening (min) -3.95 [-4.8, -3.1]; and time for extubation (min) -3.53 [-4.37, -2.7]. No significant differences were observed for either sufentanil or alfentanil about the dose of propofol required and due to scanty data, pooling of the data could not be attempted for other outcome measures for either sufentanil or alfentanil.

CONCLUSION

To conclude, we found that remifentanil has a statistically significant anesthetic profile than fentanyl when combined with propofol. Scanty evidence for both alfentanil and sufentanil precludes any such confirmation.

The analgesic efficacy and duration of lidocaine on vascular pain induced by hypertonic saline infusion: a double-blinded, randomized control trial

PURPOSE

To determine the analgesic efficacy and analgesic duration of lidocaine 20 mg and 40 mg on eliminating the vascular pain associated with hypertonic saline infusion.

METHOD

Patients who complained pain during infusion of hypertonic saline were randomized into three groups. They received normal saline (Group C), or lidocaine 20 mg (Group L20), or lidocaine 40 mg (Group L40). An electronic stopwatch was used to record the time to onset (T1) and the time to termination (T2) of the analgesic effect, and the analgesic duration (AD) was calculated as T2 - T1.

RESULTS

The incidence of pain elimination was significantly higher in both of the lidocaine groups (83.3 and 56.1% in Groups L40 and L20, respectively) than in the saline group (16.3%). Furthermore, lidocaine 40 mg was significantly more effective than 20 mg in eliminating the pain. The analgesic duration was significantly longer in Group L40 than in Group L20 (211.4 ± 50.2 vs. 130.3 ± 39.5 s, P < 0.001) and Group C (211.4 ± 50.2 vs. 45.1 ± 14.5 s, P < 0.001), and the analgesic duration in Group L20 was significantly longer than in Group C (P < 0.001). The incidence of transient tinnitus/dizziness was significantly higher in Group L40 than in Group L20 (19.0 vs. 2.4%, P < 0.05).

CONCLUSION

A single bolus of Lidocaine was effective in eliminating the pain induced by hypertonic saline infusion, but just for a short period of time. Lidocaine (without venous occlusion) only provides a short analgesic duration for local vein.

Pain during Injection of Propofol: The Effect of Prior Administration of Ephedrine

Propofol causes pain on intravenous injection in 28 to 90% of patients. A number of techniques have been tried to minimize propofol-induced pain, with variable results. In a randomized, double-blind, placebo-controlled trial, we compared the efficacy of ephedrine 30 μg/kg pretreatment to lignocaine 40 mg for prevention of propofol-induced pain. Ninety-three adult patients, ASA 1 and 2, undergoing elective laparoscopic cholecystectomy were randomly assigned to three groups of 31 each. Group 1 received normal saline, group 2 received lignocaine 2% (40 mg) and group 3 received 30 μg/kg ephedrine. All pretreatment drugs were made up to 2 ml. Pain at the time of propofol injection was assessed on a four-point scale: 0=no pain, 1=mild pain, 2=moderate pain, and 3=severe pain. Twenty-seven patients (87%) of ephedrine pretreatment patients had pain during intravenous injection of propofol as compared to 24 (77%) in the normal saline group. In the lignocaine group, propofol-induced pain was observed in only 13 (42%) when compared with other study groups (P<0.05). Pretreatment with ephedrine 30 μg/kg did not attenuate pain associated with intravenous injection of propofol, nor did it improve haemodynamic stability during induction. However, pretreatment with 2% lignocaine (40 mg) was effective in attenuating propofol-associated pain.

Preventing Pain on Injection of Propofol: A Comparison between Lignocaine Pre-treatment and Lignocaine Added to Propofol

A randomized double-blind study compared two methods of preventing the pain from injection of propofol, lignocaine pre-treatment followed by propofol and lignocaine added to propofol. One hundred patients received a 4 ml solution intravenously with a venous tourniquet for 1 minute, followed by propofol mixed with 2 ml of solution. Patients were divided into two treatment groups of 50 patients each: 4 ml 1% lignocaine pre-treatment followed by propofol and 2 ml saline, or 4 ml saline followed by propofol and 2 ml 2% lignocaine. Pain was assessed with a 100 mm visual analogue scale after induction and in recovery. The incidence of injection pain was 8% in the propofol mixed with lignocaine group, and 28% in the lignocaine pre-treatment group. This difference is statistically significant (P=0.017). For those patients who had pain, the mean pain score was 26.5 on induction for the propofol with lignocaine group (n=4), while the mean score was 44.4 for the pre-treatment group (n=13). The difference was not statistically significant (P=0.25). None of the propofol mixed with lignocaine group recalled pain, while 13 of the pre-treatment group did so. Lignocaine pre-treatment does not improve the immediate or the recalled comfort of patients during propofol induction when compared to lignocaine added to propofol. It is recommended that lignocaine should be added to propofol for induction rather than given before induction.

Clinical Pharmacokinetics and Pharmacodynamics of Propofol

Propofol is an intravenous hypnotic drug that is used for induction and maintenance of sedation and general anaesthesia. It exerts its effects through potentiation of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) at the GABAA receptor, and has gained widespread use due to its favourable drug effect profile. The main adverse effects are disturbances in cardiopulmonary physiology. Due to its narrow therapeutic margin, propofol should only be administered by practitioners trained and experienced in providing general anaesthesia. Many pharmacokinetic (PK) and pharmacodynamic (PD) models for propofol exist. Some are used to inform drug dosing guidelines, and some are also implemented in so-called target-controlled infusion devices, to calculate the infusion rates required for user-defined target plasma or effect-site concentrations. Most of the models were designed for use in a specific and well-defined patient category. However, models applicable in a more general population have recently been developed and published. The most recent example is the general purpose propofol model developed by Eleveld and colleagues. Retrospective predictive performance evaluations show that this model performs as well as, or even better than, PK models developed for specific populations, such as adults, children or the obese; however, prospective evaluation of the model is still required. Propofol undergoes extensive PK and PD interactions with both other hypnotic drugs and opioids. PD interactions are the most clinically significant, and, with other hypnotics, tend to be additive, whereas interactions with opioids tend to be highly synergistic. Response surface modelling provides a tool to gain understanding and explore these complex interactions. Visual displays illustrating the effect of these interactions in real time can aid clinicians in optimal drug dosing while minimizing adverse effects. In this review, we provide an overview of the PK and PD of propofol in order to refresh readers' knowledge of its clinical applications, while discussing the main avenues of research where significant recent advances have been made.

Risk factors for oxaliplatin-induced vascular pain in patients with colorectal cancer and comparison of the efficacy of preventive methods

Background

Vascular pain is a common adverse drug reaction in colorectal cancer patients receiving peripheral venous administration of oxaliplatin. The aim of this work was to identify risk factors for vascular pain, and to examine whether currently used treatments reduce its incidence.

Methods

We conducted a multicenter retrospective study in Japanese colorectal cancer patients receiving peripheral venous administration of oxaliplatin. The effects of various treatments (administration of analgesics, addition of dexamethasone to the infusion solution for pH adjustment, dilution of the infusion solution, or use of hot gel for warming the injection site) on the incidence of vascular pain were assessed. Risk factors for vascular pain were identified by multiple logistic regression analysis.

Results

One hundred and ninety patients who had received an oxaliplatin-containing regimen via a peripheral venous route were analyzed. None of the preventive methods examined significantly reduced the incidence of vascular pain. BMI (BMI < 22), clinical stage (I-III) and oxaliplatin dosage (130 mg/m² versus dose reduction) were identified as independent risk factors for development of vascular pain. The incidence of oxaliplatin-induced vascular pain was significantly higher in patients who had two or more risk factors.

Conclusions

BMI, clinical stage and oxaliplatin dosage were identified as independent predictive markers for oxaliplatin-induced vascular pain. Existing treatments for vascular pain are not effective in reducing its incidence.

Quantifying and presenting overall evidence in network meta-analysis

Network meta-analysis (NMA) has become an increasingly used tool to compare multiple treatments simultaneously by synthesizing direct and indirect evidence in clinical research. However, many existing studies did not properly report the evidence of treatment comparisons and show the comparison structure to audience. In addition, nearly all treatment networks presented only direct evidence, not overall evidence that can reflect the benefit of performing NMAs. This article classifies treatment networks into three types under different assumptions; they include networks with each treatment comparison's edge width proportional to the corresponding number of studies, sample size, and precision. In addition, three new measures (ie, the effective number of studies, the effective sample size, and the effective precision) are proposed to preliminarily quantify overall evidence gained in NMAs. They permit audience to intuitively evaluate the benefit of performing NMAs, compared with pairwise meta-analyses based on only direct evidence. We use four case studies, including one illustrative example, to demonstrate their derivations and interpretations. Treatment networks may look fairly differently when different measures are used to present the evidence. The proposed measures provide clear information about overall evidence of all treatment comparisons, and they also imply the additional number of studies, sample size, and precision obtained from indirect evidence. Some comparisons may benefit little from NMAs. Researchers are encouraged to present overall evidence of all treatment comparisons, so that audience can preliminarily evaluate the quality of NMAs.

Evaluation of efficacy of Valsalva maneuver for attenuating propofol injection pain: a prospective, randomized, single blind, placebo controlled study

Background

Pain on injection is a limitation with propofol use. The effect of the Valsalva maneuver on pain during propofol injection has not been studied. This maneuver reduces pain through the sinoaortic baroreceptor reflex arc and by distraction. We aimed to assess the efficacy of the Valsalva maneuver in reducing pain during propofol injection.

Methods

Eighty American Society of Anesthesiologists class I adult patients undergoing general anesthesia were enrolled and divided into two groups of 40 each. Group I (Valsalva) patients blew into a sphygmomanometer tube raising the mercury column up to 30 mmHg for 20 seconds, while Group II (Control) patients did not. Anesthesia was induced with 1% propofol immediately afterwards. Pain was assessed on a 10-point visual analog scale (VAS), where 0 represented no pain, and 10, the worst imaginable pain, and a 4-point withdrawal response score, where 0 represented no pain, and 3, the worst imaginable pain. Scores were presented as median (interquartile range).

Results

We analyzed the data of 70 patients. The incidence of pain was significantly lower in the Valsalva than in the control group (53% vs 78%, P = 0.029). The withdrawal response score was significantly lower in the Valsalva group (1.00 [0.00-1.00] vs 2.00 [2.00-3.00], P < 0.001). The VAS score was significantly lower in the Valsalva group (1.00 [0.00-4.00] vs 7.00 [6.25-8.00], P < 0.001).

Conclusions

A prior Valsalva maneuver is effective in attenuating injection pain due to propofol; it is advantageous in being a non-pharmacological, safe, easy, and time-effective technique.

Propofol induces nuclear localization of Nrf2 under conditions of oxidative stress in cardiac H9c2 cells

Oxidative stress contributes to myocardial ischemia-reperfusion injury, which causes cardiomyocyte death and precipitate life-threatening heart failure. Propofol has been proposed to protect cells or tissues against oxidative stress. However, the mechanisms underlying its beneficial effects are not fully elucidated. In the present study, we employed an in vitro oxidative injury model, in which rat cardiac H9c2 cells were treated with H₂O₂, and investigated roles of propofol against oxidative stress. Propofol treatment reduced H₂O₂-induced apoptotic cell death. While H₂O₂ induced expression of the antioxidant enzyme HO-1, propofol further increased HO-1 mRNA and protein levels. Propofol also promoted nuclear localization of Nrf2 in the presence of H₂O₂. Knockdown of Nrf2 using siRNA suppressed propofol-inducible Nrf2 and expression of Nrf2-downstream antioxidant enzyme. Knockdown of Nrf2 suppressed the propofol-induced cytoprotection. In addition, Nrf2 overexpression induced nuclear localization of Nrf2 and HO-1 expression. These results suggest that propofol exerts antioxidative effects by inducing nuclear localization of Nrf2 and expression of its downstream enzyme in cardiac cells. Finally, we examined the effect of propofol on cardiomyocytes using myocardial ischemia-reperfusion injury models. The expression level of Nrf2 protein was increased at 15 min after reperfusion in the ischemia-reperfusion and propofol group compared with ischemia-reperfusion group in penumbra region. These results suggest that propofol protects cells or tissues from oxidative stress via Nrf2/HO-1 cascade.

Recent advances in intravenous anesthesia and anesthetics

Anesthesiology, as a field, has made promising advances in the discovery of novel, safe, effective, and efficient methods to deliver care. This review explores refinement in the technology of soft drug development, unique anesthetic delivery systems, and recent drug and device failures.

Bayesian hierarchical models for network meta-analysis incorporating nonignorable missingness

Network meta-analysis expands the scope of a conventional pairwise meta-analysis to simultaneously compare multiple treatments, synthesizing both direct and indirect information and thus strengthening inference. Since most of trials only compare two treatments, a typical data set in a network meta-analysis managed as a trial-by-treatment matrix is extremely sparse, like an incomplete block structure with significant missing data. Zhang et al. proposed an arm-based method accounting for correlations among different treatments within the same trial and assuming that absent arms are missing at random. However, in randomized controlled trials, nonignorable missingness or missingness not at random may occur due to deliberate choices of treatments at the design stage. In addition, those undertaking a network meta-analysis may selectively choose treatments to include in the analysis, which may also lead to missingness not at random. In this paper, we extend our previous work to incorporate missingness not at random using selection models. The proposed method is then applied to two network meta-analyses and evaluated through extensive simulation studies. We also provide comprehensive comparisons of a commonly used contrast-based method and the arm-based method via simulations in a technical appendix under missing completely at random and missing at random.

Prevention of propofol injection-related pain using pretreatment transcutaneous electrical acupoint stimulation

Background/aim: This study aimed to study the effect of pretreatment transcutaneous electrical acupoint stimulation (TEAS) in preventing propofol injection-related pain. Materials and methods: A total of 360 patients who were to undergo elective hysteroscopy surgery were randomly divided into the following three groups of 120 patients each: control (Group C), sham TEAS (Group F), and TEAS (Group T). Patients in Group C did not undergo any treatment before surgery; 30 min before the induction of anesthesia, patients in Groups F and T underwent electrical stimulation of the bilateral LI4-PC6 acupoint. Patients in Group F were subjected to 'feeling flow', while those in Group T were subjected to 'tolerance flow.' The stimulation frequency was 2/100 Hz and the duration of stimulation was 30 min. After the induction of anesthesia, propofol injection-related pain scores, hemodynamic parameters, and adverse reactions were recorded. Results: Of the 360 patients, 324 completed the study. There were significant differences among the groups in terms of the incidence of moderate-to-severe pain. In terms of the four-point scaling method, the end of the radial vein, the cubital vein, and the 'back of the hand' vein differed significantly among the three groups (P = 0.05). Finally, using a numerical rating scale, a significant difference was observed among the three groups in terms of the pain scores in the different veins. Conclusions: Pretreatment TEAS effectively reduces the incidence and severity of propofol injection-related pain, the incidence of postoperative nausea and vomiting, and patient postoperative pain scores.

Effective Dosage of Midazolam to Erase the Memory of Vascular Pain During Propofol Administration

Intravenous sedation with propofol is often administered to anxious patients in dental practice. Pain on injection of propofol is a common adverse effect. This study aimed to determine the age-adjusted doses of midazolam required to erase memory of vascular pain of propofol administration and assess whether the Ramsay Sedation Scale (RSS) after the pretreatment of midazolam was useful to predict amnesia of the vascular pain of propofol administration. A total of 246 patients with dental phobia requiring dental treatment under intravenous sedation were included. Patients were classified according to their age: 30s, 40s, 50s, and 60s. Three minutes after administration of a predetermined dose of midazolam, propofol was infused continuously. After completion of the dental procedure, patients were interviewed about the memory of any pain or discomfort in the injection site or forearm. The dosage of midazolam was determined using the Dixon up-down method. The first patient was administered 0.03 mg/kg, and if memory of vascular pain remained, the dosage was increased by 0.01 mg/kg for the next patient, and then if the memory was erased, the dosage was decreased by 0.01 mg/kg. The effective dosage of midazolam in 95% of each age group for erasing the memory of propofol vascular pain (ED95) was determined using logistic analysis. The accuracy of RSS to predict the amnesia of injection pain was assessed by receiver operating characteristic (ROC) analysis. The ED95 of midazolam to erase the memory of propofol vascular pain was 0.061 mg/kg in patients in their 30s, 0.049 mg/kg in patients in their 40s, 0.033 mg/kg in patients in their 50s, and 0.033 mg/kg in patients in their 60s. The area under the ROC curve was 0.31. The ED95 of midazolam required to erase the memory of propofol vascular pain demonstrated a downward trend with age. On the other hand, it was impossible to predict the amnesia of propofol vascular pain using the RSS.

Lornoxicam use to reduce the pain associated with propofol injection

Aim: To investigate the efficacy of lornoxicam in the prevention of the pain associated with propofol injection.

Material and method: Approval for this study was granted by the ethics committee of our hospital. Using a computer randomisation software, 120 patients undergoing elective surgery were assigned to four equal groups. In Group I (control group), immediately before anaesthesia induction, 10 ml of isotonic 0.9% NaCl solution (placebo) was administered intravenously (IV). In Groups II, III and IV, the same injection contained 2 mg, 4 mg and 8 mg of lornoxicam respectively. A tourniquet was then applied to the forearm for two minutes. Pain evaluation was made using a verbal pain score.

Results: Differences in pain severity scores were statistically significant between Groups I and II, Groups I and III, Groups I and IV and between Groups II and III (p < 0.05). However, no significant difference was determined between Groups III and IV (p = 0.401).

Conclusion: In all groups administered with lornoxicam, there was a significant reduction in the severity of pain associated with propofol injection, in comparison with the control group. Maximum effect is obtained with a dose of 4 mg.

Identification of a putative binding site critical for general anesthetic activation of TRPA1

General anesthetics suppress CNS activity by modulating the function of membrane ion channels, in particular, by enhancing activity of GABA_A receptors. In contrast, several volatile (isoflurane, desflurane) and i.v. (propofol) general anesthetics excite peripheral sensory nerves to cause pain and irritation upon administration. These noxious anesthetics activate transient receptor potential ankyrin repeat 1 (TRPA1), a major nociceptive ion channel, but the underlying mechanisms and site of action are unknown. Here we exploit the observation that pungent anesthetics activate mammalian but not Drosophila TRPA1. Analysis of chimeric Drosophila and mouse TRPA1 channels reveal a critical role for the fifth transmembrane domain (S5) in sensing anesthetics. Interestingly, we show that anesthetics share with the antagonist A-967079 a potential binding pocket lined by residues in the S5, S6, and the first pore helix; isoflurane competitively disrupts A-967079 antagonism, and introducing these mammalian TRPA1 residues into dTRPA1 recapitulates anesthetic agonism. Furthermore, molecular modeling predicts that isoflurane and propofol bind to this pocket by forming H-bond and halogen-bond interactions with Ser-876, Met-915, and Met-956. Mutagenizing Met-915 or Met-956 selectively abolishes activation by isoflurane and propofol without affecting actions of A-967079 or the agonist, menthol. Thus, our combined experimental and computational results reveal the potential binding mode of noxious general anesthetics at TRPA1. These data may provide a structural basis for designing drugs to counter the noxious and vasorelaxant properties of general anesthetics and may prove useful in understanding effects of anesthetics on related ion channels.

Efficacy of lidocaine on preventing incidence and severity of pain associated with propofol using in pediatric patients: A PRISMA-compliant meta-analysis of randomized controlled trials

BACKGROUND

Propofol injection pain was considered as one conundrum during clinical anesthesia. The systematic review about the effect of lidocaine in reducing injection pain among children has not been established. The aim of the study was to systematically evaluate the efficacy and safety of such intervention.

METHODS

The literature search was performed from the inception to the May 31, 2016 in PubMed, Ovid EMBASE, and Cochrane database. All randomized controlled trials that using lidocaine for propofol injection pain in children were enrolled. The primary outcome included the incidence of injection pain and the incidence of propofol injection pain in different degrees. The data were combined to calculate the relative ratio and relevant 95% confidence interval. A meta-analysis was performed following the guidelines of the Cochrane Reviewer's Handbook and the PRISMA statement.

RESULTS

Data from the included 11 studies indicated that the incidence of injection pain was lower in lidocaine group than the incidence in saline control group and in propofol lipuro (medium- and long-chain triglycerides) group (pain occurrence: 22.1% in lidocaine vs 66.8% in saline, RR with 95% 0.34 [0.26, 0.43], I = 38%; 30.5% in lidocaine vs 46.9% in propofol lipuro, RR with 95% 0.68 [0.46, 1.00], I = 9%). There was no difference between lidocaine and ketamine/alfentanil both in reducing pain occurrence and in reducing pain severity (pain occurrence: 29.7% in lidocaine vs 25.8% in ketamine, RR with 95% 1.47 [0.16, 13.43], I = 94%; 31.0% in lidocaine vs 30.7% in alfentanil, RR with 95% 1.01 [0.69, 1.46], I = 11%). And the reported side effects revealed that the safety of lidocaine in pediatric patients was acceptable.

CONCLUSION

Compared with ketamine and alfentanil, lidocaine would be served as one more effective treatment in consideration of its well-matched efficacy, acceptable accessibility, and reasonable safety. However, more high-quality evidences in pediatric patients are necessary.