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In a randomized, double-blind, prospective trial we compared the efficacy of pre-treatment with nitrous oxide (with or without premixed lignocaine in propofol) for the prevention of propofol-induced pain. Ninety consecutive patients were recruited in the study and divided into three groups of 30 each, who received either 50% nitrous oxide in oxygen along with lignocaine 40 mg mixed in 1% propofol 20 ml (Group NL), 50% nitrous oxide in oxygen without lignocaine in propofol (Group N), and 50% oxygen in air with lignocaine mixed in propofol 40 mg (Group L). Pain scores were graded on a four point verbal rating scale (0–3). Eighty-nine patients completed the study while one patient developed excitement, agitation and tremor during nitrous oxide in oxygen inhalation. Eleven patients (36.7%) complained of pain in the group L compared to 7 (23.3%), and 1 (3.3%), in groups N and NL respectively [group NL vs group L (P

UNLABELLED Propofol causes pain on IV injection in 28%-90% of patients. A number of techniques have been tried to minimize propofol-induced pain, with variable results. We compared the efficacy of pretreatment with thiopental 0.25 mg/kg and 0.5 mg/kg and lidocaine 40 mg after venous occlusion for prevention of propofol-induced pain. One-hundred-twenty-four adult patients, ASA physical status I-II, undergoing elective surgery were randomly assigned into 4 groups of 31 each. Group I received normal saline, group II received lidocaine 2% (40 mg), and groups III and IV received thiopental 0.25 mg/kg and 0.5 mg/kg, respectively. All pretreatment drugs were made in 2 mL and were accompanied by manual venous occlusion for 1 min. Propofol was administered after release of venous occlusion. Pain was assessed with a four-point scale: 0 = no pain, 1 = mild pain, 2 = moderate pain, and 3 = severe pain at the time of propofol injection. Twenty-four patients (77%) complained of pain in the group pretreated with normal saline as compared with 12 (39%), 10 (32%), and 1 (3%) in the groups pretreated with lidocaine 40 mg, thiopental 0.25 mg/kg, and thiopental 0.5 mg/kg, respectively (P < 0.05). Thiopental 0.5 mg/kg was the most effective treatment. We therefore suggest routine pretreatment with thiopental 0.5 mg/kg along with venous occlusion for 1 min for prevention of pain associated with propofol injection. IMPLICATIONS Pain associated with IV injection of propofol is seen in 28%-90% patients. Pretreatment with thiopental 0.25 mg/kg and 0.5 mg/kg after manual venous occlusion for 1 min effectively attenuated pain associated with propofol injection. Thiopental 0.5 mg/kg was the most effective in prevention of propofol pain and can be used routinely.

Objective A disadvantage of Propofol (commercial preparation containing long-chain triglycerides; Propofol-LCT) is pain on injection, which is reported by 54 - 100 % of the patients. Many different approaches have been used in an attempt to decrease the pain on injection of propofol. The currently most efficacious treatment is lidocaine given intravenously with a tourniquet prior to Propofol injection. In previous studies, larger concentrations of free propofol in the aqueous phase of an emulsion were associated with more pain on injection. A new formulation of propofol (a mixture of long-chain and medium-chain triglycerides in the carrier emulsion; Propofol-MCT/LCT) reduces the incidence of pain on bolus injection. This study was designed to investigate, whether the use of Propofol-MCT/LCT alleviates pain on injection to a similar degree as pretreatment with lidocaine. Methods Eighty patients (ASA I - III) were randomly assigned to four groups according to a double-blinded protocol, to receive either lidocaine 2 % or normal saline given iv. with a 60 seconds tourniquet time before the injection of Propofol-LCT or Propofol-MCT/LCT. (group 1: 2 ml NaCl 0,9 %, Propofol-LCT; group 2: 2 ml NaCl 0,9 %, Propofol-MCT/LCT; group 3: 2 ml lidocaine 2 %, Propofol-LCT; group 4: 2 ml lidocaine 2 %, Propofol-MCT/LCT). Assessment of pain on injection was performed after 30 % of the induction dose was given. Results Pain on injection caused by Propofol-LCT with pre-treatment of lidocaine and Propofol-MCT/LCT alone is shown to be equivalent. Comparison of Propofol-MCT/LCT with pre-treatment of lidocaine and Propofol-LCT alone shows a statistical noticeable p-value of 0.035. Propofol-MCT/LCT with pre-treatment of lidocaine suggests a tendency of causing less pain compared to Propofol-MCT/LCT. Analysis of the postoperative questionnaire supplies no significant difference. Conclusion The results suggest that pain on injection is reduced equivalent using either Propofol-MCT/LCT alone or Propofol-LCT with pre-treatment of lidocaine. Pre-treatment with lidocaine before Propofol-MCT/LCT seems to have an additional effect.

Background and Aims: Propofol injection pain is an unresolved problem in children. Although medium and long chain triglyceride (MCT-LCT) propofol has shown promising results in adults, its efficacy in children is not proven. In a prospective observational study the incidence and severity of pain with MCT-LCT and LCT propofol in children was compared. Methods: After obtaining approval from the Institutional Ethics Committee, 170 children (age group 6 months to 8 years) scheduled for various surgeries were included in this study. Following standard pre-medication, propofol 1% either LCT or MCT-LCT in a dose of 2–4 mg/kg along with preservative-free lignocaine (2% lignocaine 1 mg in propofol 10 mg) was administered. The primary objective was to study injection pain on scale of 0–6. For children ≤2 years doubling of motor event score (0–3) and for children >2 years, addition of motor (0–3) and verbalisation scores (0–3) were considered. Mann–Whitney U test was used for statistical analysis. Results: MCT-LCT group had lower incidence of pain (17 patients (20%) versus 35 patients (35.3%), P = 0.026) and severe pain (zero patients (0%) versus six patients (7.1%), P = 0.029) as compared to LCT group. MCT-LCT group had significantly lower mean rank of motor (79.65 versus 91.35), verbal (77.29 versus 90.79) and total score (77.76 versus 93.24) as compared to LCT group (P = 0.037, 0.002, and 0.009, respectively). Conclusion: MCT-LCT propofol is associated with significantly lower injection pain as compared to LCT propofol in children, when both are combined with lignocaine.

One hundred seventy-six patients (ASA physical status I or II) presenting for elective surgery were randomly allocated into six study groups to compare the incidence of propofol-induced pain after pretreatment with different doses of ephedrine as compared with lidocaine. Patients in Group P (n = 30) received saline placebo; patients in Group L (n = 30) received 2% lidocaine 40 mg; patients received ephedrine 30 microg/kg (Group E30, n = 28), 70 microg/kg (Group E70, n = 30), 110 microg/kg (Group E110, n = 30), and 150 microg/kg (Group E150, n = 28), respectively, followed 30 s later by propofol 2.5 mg/kg. A blinded anesthesiologist asked the patient to evaluate the pain score (verbal rating scale and face pain scale). The incidence and intensity of pain was less in the lidocaine and ephedrine groups than in the placebo group (P0.01). Before tracheal intubation, the arterial blood pressure was decreased in the P and L groups, and after intubation, hemodynamics were increased in the E110 and E150 groups, respectively (P0.05). We concluded that pretreatment with a small dose of ephedrine (30 and 70 microg/kg) reduced the incidence and intensity of propofol-induced pain with a lesser decrease in arterial blood pressure than from propofol alone in lidocaine pretreatment.Propofol is a widely used IV anesthetic for the induction of anesthesia, but it often causes local pain when administered into peripheral veins. A small dose of ephedrine reduces the incidence and intensity of the pain without significant adverse hemodynamic effects during induction.

Background: Pain on injection is still a major problem with propofol. We performed this study to compare different doses of intravenous (i.v.) ketorolac with and without venous occlusion and its effect on the incidence and the severity of the pain after propofol injection. Methods: We conducted a prospective, randomized and double-blind study of 180 patients (20–60 years of age.) scheduled to undergo elective surgery. Six groups of patients were generated: group A received normal saline (NS) 2 ml i.v.; groups B, C, D received ketorolac 10 mg in 2 ml NS with venous occlusion (VO) and a subsequent propofol injection at either 30, 60 or 120 s; groups E and F received ketorolac 15 mg and 30 mg in 2 ml NS and propofol was injected after 60 s. The pain perception was assessed during injection of propofol in all patients. Result: The incidence of propofol-associated injection pain was for A: 46.7%; B: 43.4%; C: 23.3%; D:16.7%; E: 20%, and F: 10%. The incidence of pain following propofol injection was reduced by i.v. ketorolac 10 mg with venous occlusion for 120 s. Furthermore, i.v. ketorolac 15 mg and 30 mg but not 10 mg following propofol injection after 60 s without venous occlusion revealed significant pain reduction when compared to saline group. There was no difference in venous sequelae at 7 days postoperatively between the groups. Conclusion: Our results suggested that pretreatment with i.v. 15 and 30 mg ketorolac reduces pain following propofol injection. Moreover, pretreatment with i.v. ketorolac 10 mg with venous occlusion for 120 s achieves the same pain relief effect.

Summary In a randomised, double-blinded, two-centre trial we evaluated the effect of a microbiological filter (Supor®, Pall Life Sciences) on propofol injection pain. We studied 336 unpremedicated adult patients, who graded pain experienced during induction of anaesthesia with propofol on a 4-point verbal rating scale. Use of the microfilter reduced both the incidence and severity of propofol injection pain (p

Electroconvulsive Therapy(以下ECT)においてプロポフォールまたはチオペンタールにて麻酔し,投与量の増減によってそれぞれを2群に分け,ECTによる痙攣時間と循環動態の変動を検討した.両薬剤ともに投与量が増すと循環動態は安定したが,投与量が少ないとチオペンタール群で変動が大きかった.プロポフォールは投与量を増すと痙攣時間が有意に短くなったが,チオペンタールは投与の増量による痙攣時間の短縮幅が小さかった.痙攣時間の観点からはプロポフォールの投与量は1.4mg・kg-1までにとどめるべきである.プロポフォールは,循環制御のため投与量をそれ以上増すと肉眼的観察をする限りECTの痙攣時間が短縮してしまう点でECTの麻酔として望ましくない.

BACKGROUND AND OBJECTIVES: The introduction of propofol (2,6-diisopropylphenol) as a sedative agent has transformed the area of sedation for endoscopic procedures. However, a major drawback of sedation with the use of propofol is its high incidence of injection pain. The most widely used technique in reducing propofol injection pain is through the association of other drugs. The aim of this study was to evaluate the effect of remifentanil-propofol combination on the incidence of propofol injection pain and its influence on the total dose of propofol required for sedation in upper digestive tract endoscopy (UDE) diagnostic tests. METHOD: One hundred and five patients undergoing upper digestive tract endoscopy were evaluated and randomly divided into 3 groups of 35 patients each. The Control Group received propofol alone; Study-group 1 received remifentanil at a fixed dose of 0.2 mg/kg combined with propofol; Study-group 2 received remifentanil at a fixed dose of 0.3 mg/kg combined with propofol. The incidence of propofol injection pain and the total dose of propofol required for the test were evaluated. The sample was very similar regarding age, weight, height, sex, and physical status. Statistical analysis was performed according to the nature of the evaluated data. Student'st-test was used to compare the mean of age, weight, height (cm), and dose (mg/kg) variables between groups. The χ2 test was used to compare sex, physical status, and propofol injection pain between groups. The significance level was a < 0.05. RESULTS: There was significant statistical difference between the study groups and the control group regarding the parameters of propofol injection pain and total dose of propofol (mg/kg) used. However, there were no statistical differences between the two study groups for these parameters. CONCLUSION: We conclude that the use of remifentanil at doses of 0.2 mg/kg and 0.3 mg/kg was effective for reducing both the propofol injection pain and the total dose of propofol used. JUSTIFICATIVA E OBJETIVOS: A introdução do propofol (2,6-di-isopropilfenol) como agente sedativo tem transformado a área da sedação para procedimentos endoscópicos. Entretanto, um grande inconveniente da sedação com o uso do propofol é sua alta incidência de dor à injeção. A técnica mais usada na redução da dor à injeção do propofol tem sido a associação com outros fármacos. O objetivo deste estudo foi avaliar a repercussão da associação do remifentanil com o propofol na incidência de dor à injeção de propofol e a influência na dose total de propofol necessária para sedação em endoscopia digestória alta (EDA) diagnóstica. MÉTODO: Foram avaliados 105 pacientes, submetidos à EDA diagnóstica e divididos aleatoriamente em três grupos de 35. O Grupo Controle foi sedado apenas com propofol. O Grupo de Estudo 1 foi sedado com remifentanil em dose fixa de 0,2 µg/kg associado ao propofol. E o Grupo de Estudo 2 foi sedado com remifentanil em dose fixa de 0,3 µg/kg associado ao propofol. Foram avaliadas a incidência de dor à injeção de propofol e a dose de propofol necessária para o exame. A amostra se mostrou bastante similar em relação às variáveis idade, peso, altura, sexo e estado físico. De acordo com a natureza dos dados estudados, procedeu-se ao tratamento estatístico julgado adequado. Usou-se o teste t para comparação, entre os grupos analisados, das médias das variáveis idade, peso, altura (cm) e dose (mg/kg). Foi usado o teste ?2 para comparação, entre os grupos analisados, das variáveis sexo, estado físico e dor à injeção de propofol. O nível de significância adotado foi a < 0,05. RESULTADO: Houve diferença estatística significativa entre os grupos de estudo e o grupo controle tanto no parâmetro dor à injeção de propofol quanto no parâmetro dose de propofol usada (mg/kg). Entretanto, não houve diferenças estatísticas entre os dois grupos de estudo para esses parâmetros. CONCLUSÃO: O uso do remifentanil nas doses de 0,2 µg/kg e de 0,3 µg/kg mostrou-se efetivo tanto sobre o parâmetro redução da dor à injeção de propofol quanto sobre o parâmetro dose de propofol usada.

Pulse transit time (PTT) is the time that it takes for the arterial pulse pressure wave to travel from the aortic valve to the periphery. It is a simple noninvasive technique for evaluating vascular changes. This study investigated the vascular changes by propofol during the induction of anesthesia in pediatric patients with the measuring of PTT. Without premedication, 2 mg/kg of propofol was administered intravenously with monitoring of electrocardiogram (ECG) and photoplethysmograph (PPG) in 20 pediatric patients aged 3–7 years. The ECG and PPG data were obtained for 1 min before propofol injection (baseline PTT) and 2 min after administration of propofol in the operating room. The PTT was defined as the time interval from the R-wave on the ECG to the maximum upslope of the corresponding PPG. The PTT was calculated off-line after collecting the data. The mean baseline PTT was 166.2 ± 25.9 ms and maximum PTT after propofol injection was 315.9 ± 64.9 ms (the interval between injection and the peak was 17.3 ± 7.6 s). The PTT after the peak changed variously; most of the patients showed no plateau; the PTT decreased progressively after the peak. The PTT after propofol administration prolonged in short time and rapidly recovered toward to the baseline values in pediatric patients. In conclusion, the baseline PTT in children is shorter comparing with adults and the vasodilatory effect of propofol on the vessels as described by the PTT was rapid and the recovery was faster, although the response to propofol was more varied than in adults.

This research aimed to examine the time of onset and sedation on diabetic mellitus (DM) rat (Rattus norvegicus) by propofol. This study used 8 female wistar rats 2-3 months old and 150-200 grams of bodyweight, fed with standard feed and water ad libitum. Samples were divided into two groups. Group 1 (KI) as a control group was injected intraperitoneally with aloxan solvent and group 2 (KII) was injected intraperitoneally with 150 mg/kg bodyweight aloxan. Blood glucose was checked 10 days after aloxan injection, DM was categorized if the blood glucose over 150 mg/dl. All rats were injected intravenously with propofol 1% with the dose of 10 mg/kg bodyweight. Onset and sedation time was counted using stopwatch after propofol injection. The result showed that mean (±SD) of onset on KI and KII were 1.39±0.49 and 8.64±1.23 seconds, consecutively and they were significantly different at P0.01. Whilst mean (±SD) of sedation KI and KII were 12.12±1.47 minutes and 7.62±1.61 minutes, respectively. The onset and sedation time of KI was significantly different from KII P0.01. The conclusion of this research was DM affects time of onset and sedation when wistar strain rats were anesthetized by 1% propofol.Key words: rats, diabetic mellitus, propofol, onset, sedation

Background: Propofol is one of common anesthetic drugs used in anesthesia. The most common side effects of propofol are local pain. Pretreatment with lidocaine can reduce propofol injection pain. Objectives: The aim of the present study was to assess and compare the efficiency of lidocaine 0.4% and 2% in reducing the incidence and severity of propofol injection pain. Patients and Methods: This was a double blind prospective clinical trial on children 4-8 years old with class ASA I and II candidates who were referred to Dr. Shaikh Hospital in Mashhad for elective surgery. Sample size calculated 50 patients in each groups based on pilot study. 100 children's were randomly divided equally in two groups, who were injected with lidocaine solutions 2% and 0.4% respectively. patient's pain evaluation based on VSD (verbal descriptor scale) and NRS (Numeric Rating Scale) using patient's verbal reaction and behavior namely fretting, hand drag and tearing. The collated data was analyzed. Results: There was nosignificant difference as to the first three variables (age, gender and weight P > 0.2). The significant difference regarding pain experience in both groups was noteworthy (P > 0.2). Conclusions: Most of the studies compared lidocaine with other drugs or its efficiency at different doses. Our study is different in that we applied a constant dose of lidocaine in various volumes and concentration. This result shows that lidocaine with the same does but lower concentration and higher volume is more effective in preventing propofol injection pain. Using diluted lidocaine with the dosage of 1 mg/ kg and a concentration of 0.4% is an effective way to relieve pain caused by propofol injection in children. Implication for health policy/practice/research/medical education: In this study lidocaine was used as the main pretreatment drug to reduce propofol injection pain, with the same dose but at different volume and concentration. The aim of the present study was to assess and compare the efficiency of lidocaine 0.4% and 2% in reducing the incidence and severity of propofol injection pain.

Objectives To investigate the efficacy of pretreatment with cisatracurium for prevention of pain associated with propofol injection, and compare its efficacy with that of lidocaine. Methods Patients undergoing general anaesthesia were randomized to receive normal saline (control group), lidocaine (0.5 mg/kg), 0.03 mg/kg cisatracurium or 0.15 mg/kg cisatracurium. All drugs were administered into the largest dorsal vein of the hand with venous occlusion for 30 s, followed by propofol (0.5 mg/kg). Pain was evaluated using a four-point scale. Results The incidence and severity of pain was significantly lower in the lidocaine and 0.15 mg/kg cisatracurium groups than the control and 0.03 mg/kg cisatracurium groups (n = 50/group). There was no significant difference between the lidocaine and 0.15 mg/kg cisatracurium groups in the incidence and severity of pain. Conclusions 0.15 mg/kg cisatracurium effectively decreases the incidence and severity of pain induced by propofol injection without any significant complications.

This study aimed to assess pharyngeal function between no bolus and bolus propofol induced sedation during gastric endoscopic submucosal dissection. A retrospective study was conducted involving consecutive gastric cancer patients. Patients in the no bolus group received a 3 mg/kg/h maintenance dose of propofol after the initiation of sedation without bolus injection. All patients in the bolus group received the same maintenance dose of propofol with bolus 0.5 mg/kg propofol injection. Pharyngeal functions were evaluated endoscopically for the first 5 min following the initial administration of propofol. Fourteen patients received no bolus propofol induction and 13 received bolus propofol induction. Motionless vocal cords were observed in 2 patients (14%) in the no bolus group and 3 (23%) in the bolus group. Trachea cartilage was not observed in the no bolus group but was apparent in 6 patients (46%) in the bolus group (P<0.01). Scope stimulated pharyngeal reflex was observed in 11 patients (79%) in the no bolus group and in 3 (23%) in the bolus group (P<0.01). Propofol induced sedation without bolus administration preserves pharyngeal function and may constitute a safer sedation method than with bolus.

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.

The stability of thiopental sodium and propofol in an admixture stored in polypropylene syringes at room temperature and under refrigeration was studied. Propofol injection 10 mg/ mL and thiopental sodium 25 mg/mL were mixed to final concentrations of 5 and 12.5 mg/mL, respectively. The admixture was put into 60-mL polypropylene syringes, and two syringes were stored at 23 degrees C and two at 4 degrees C. For solutions stored at 23 degrees C, samples were taken at 0, 4, 8, 24, 48, 72, 120, 168, 216, 240, and 264 hours, and for samples stored at 4 degrees C, samples were taken at 0, 4, 8, 24, 48, 72, 120, 168, 216, and 312 hours. Drug concentrations were determined by high-performance liquid chromatography. Thiopental sodium and propofol retained > 90% of their initial concentrations for up to 312 hours at 4 degrees C. At 23 degrees C, > 90% of the initial concentration was retained by propofol for up to 120 hours and by thiopental sodium for up to 240 hours. No visual changes or significant change in pH occurred in any sample. When mixed and stored in polypropylene syringes, propofol 5 mg/mL and thiopental sodium 12.5 mg/mL were stable for up to 312 hours at 4 degrees C and for up to 120 hours at 23 degrees C.

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

Objective: Propofol is the induction agent of choice in modern anesthetic practice because of its rapid onset, short duration of action, easy titration, and favorable side effect profile. Pain on injection of anesthetic is an important source of patient dissatisfaction and is a recognized adverse effect of propofol. We compared the effects of pretreatment of palonosetron and saline (placebo) in ameliorating propofol injection pain. Materials and Methods: Sixty adult patients of either sex (18–50 years, American Society of Anesthesiologists I and II) were randomized into two equal groups (n = 30) to receive either 1.5 ml of intravenous saline (placebo) or 1.5 ml of 75 mg palonosetron to compare the pain relieving effects of the drugs during propofol injection before the patients had lost consciousness. The propofol injection pain was assessed according to McCririck and Hunter scale. Results: The palonosetron group had significantly (P < 0.05) more patients (86.67%) without propofol injection pain as compared with the saline group (56.67%). Conclusion: Pretreatment with palonosetron with venous occlusion for 1 min can effectively reduce the incidence of propofol injection pain.

Background: Propofol injection pain is one of the significant drawbacks to its use as an intravenous (IV) anesthetic induction agent so this study has been undertaken to compare the efficacy of IV acetaminophen and lidocaine on propofol injection pain. Materials and Methods: After obtaining Institutional Ethical Committee approval, ninety adult patients of ages 18–60 years of both sexes and American Society of Anaesthesiologist I and II who underwent elective surgery from September 2013 to September 2015 in the Tertiary Care Hospital, Imphal, were randomly allocated to one of the three groups to receive 10 ml saline (Group 1), 40 mg lidocaine (loxicard) in 10 ml saline (Group 2) and acetaminophen 100 mg (10 ml) (Group 3) to compare the pain efficacy during propofol injection into the large dorsal vein on the left hand. Pain was assessed with a verbal rating scale. Results: It was observed that the number of patients experiencing pain was 20 (66.67%), i.e., mild: moderate: severe - 11 (36.67%): 6 (20%): 3 (10%) in Group 1, in Group 2 the incidence was 2 (6.67%) i.e., mild: moderate: severe - 2 (6.67%): 0: 0, and in Group 3 it was 6 (20%) i.e., mild: moderate: severe - 5 (16.67%): 1 (3.33%): 0, respectively (P < 0.001). Conclusion: IV acetaminophen and lidocaine could significantly reduce pain during propofol injection with a significant P< 0.001.

BACKGROUND Propofol, an intravenous anesthetic, often causes pain on injection, which can be very distressful to patients. We investigated the analgesic effect of pregabalin on pain following propofol injection, compared with lidocaine. METHODS In a randomized, double-blind, prospective trial, 120 patients were randomized into 3 groups of 40 each; who received oral placebo and intravenous lidocaine 40 mg with venous occlusion for 1 minute (group L, n = 40), oral pregabalin 75 mg and intravenous normal saline with venous occlusion for 1 minute (group LP, n = 40), and oral pregabalin 150 mg and intravenous normal saline with venous occlusion for 1 minute (group HP, n = 40) as pretreatment, followed by administration of 1% propofol 0.5 mg/kg. Pain intensity was measured on a 4-point scale (0 = no, 1 = mild, 2 = moderate, and 3 = severe pain). Any side effects associated with pretreatment substances were recorded during the first 24 hours after surgery. RESULTS A total of 120 patients completed this trial. Demographic data were similar between groups. The incidence of pain following propofol injection was significantly reduced in group HP (50%) and group L (55%) compared with group LP (92.5%) (P

To the Editor, We read with great interest the article by Kwon et al., in which the authors concluded that pretreatment with 1 % lidocaine 20 mg was effective in preventing propofol pain compared with placebo during upper gastrointestinal endoscopy [1]. We all agree with the idea that propofol pain is currently a common problem, not only in general anesthesia but also in nonoperation room anesthesia which is applied with sedation for various procedures. Therefore it is important to prevent propofol pain, and many techniques and drugs are used for its prevention as the authors specified in the article. Additionally, we think that it is important here to determine the other issues with propofol pain which are not emphasized in the publication and may affect the results. It has been shown that the propofol formulation is also an impressive factor in propofol pain. The concentration of free propofol in the aqueous phase is known to be associated with the intensity of pain on injection [2]. Although the LCT and LCT/MCT formulas of propofol have equal effect, the amount of free propofol which is believed to be responsible for injection pain is much more in the propofol LCT formulation when compared with the MCT/LCT formulation [3, 4]. Besides, according to our experience [5] and the studies on propofol pain, it is suggested that to reduce the pain elicited by the iv injection of propofol, the most common medication is to give lidocaine in a variety of rates, doses and concentrations [6]; especially pretreatment with iv 0.5 mg/ kg lidocaine is the optimal method for reducing pain caused by propofol [5]. Therefore, we suggest that the emulsion with MCT/LCT formulation of propofol with the pretreatment of 0.5 mg/kg lidocaine or premixing propofol with 20 mg lidocaine to reduce the concentration of free propofol in the aqueous phase of the emulsion may be more effective in preventing propofol pain during upper endoscopy. Further studies are needed to corroborate our suggestions in preventing pain of low dose propofol in sedation for different endoscopic procedures.

Pain at the site of propofol injection is a real problem which requires particular attention in children. In adults, undergoing planned surgery, premedication or opioid administration prior to propofol seem to sufficiently reduce the frequency and severity of the pain induced by the injection of the agent into a distal arm vein. Adding lidocaine to propofol just before the injection is debatable in day-case procedures, especially if the injection is carried out on the dorsum of the hand. In children, intravenous administration of lidocaine seems to be more routinely performed, whatever the type of surgery.

IMPLICATIONS Magnesium sulfate, 2.48 mmol, injected 20 s before the administration of propofol significantly reduced the incidence of pain caused by a propofol injection and may be useful in minimizing this common side effect.

Objective: Findings from studies investigating optimal techniques for attenuating propofol-related injection pain are inconsistent. In previous studies, lidocaine pretreatment using a tourniquet has been reported to be superior, inferior, or equivalent to a lidocaine-propofol admixture for reducing pain. This discordance could represent either no meaningful difference in the treatments or underlying methodological differences in the previous studies. We hypothesized that tourniquet-controlled pretreatment with lidocaine would be superior to lidocaine-propofol admixture for reducing propofol injection pain. Methods: This randomized controlled trial compared 3 groups-a control group (saline pretreatment/saline admixture; n = 50), a pretreatment group (lidocaine pretreatment/saline admixture; n = 51), and an admixture group (saline pretreatment/lidocaine admixture; n = 50). The primary outcome was verbal pain score after injection. The incidence of pain on injection was explored as a secondary outcome. Results: The median (interquartile range) verbal pain score after study solution injection were as follows-control group: 3 (0-6), pretreatment group: 0 (0-0), and admixture group: 0 (0-2). The pretreatment group had significantly lower pain scores when compared with the admixture group (P = 0.016), and both groups were superior to the control group. The pretreatment group had fewer subjects experiencing any injection pain than did the admixture group (20% vs. 44%, respectively; P = 0.024). Conclusions: Tourniquet-controlled pretreatment with lidocaine is statistically superior to admixing lidocaine with propofol for reducing propofol injection pain intensity, but the clinical importance of this small effect is questionable. However, pretreatment more effectively eliminates injection pain.

Background: Pain upon the injection of propofol is a common adverse effect. This study was conducted to evaluate the analgesic effect of remifentanil and cold propofol during propofol injection for the induction of anesthesia and to determine if a combination of cold propofol and remifentanil produced additional analgesic efficacy. Methods: A total of 160 patients aged 20-65 years old were randomly allocated into one of four groups (n = 40, in each). Control and remifentanil group patients received 2 mg/kg propofol that had been stored at room temperature (20-23 o C), while the cold and combination group received cold (4 o C) propofol. The patients received remifentanil 0.5 μg/kg IV in the remifentanil and combination groups or saline in the control and cold groups. Ninety seconds after administration the patients were administered propofol over a 30 second period. The pain intensity and incidence were then evaluated using a 4-point verbal rating scale. Results: The incidence of pain was significantly reduced in groups that received remifentanil in the cold and combination groups when compared with the control group (27.5%, 30%, and 2.5% vs. 70%, respectively). Moreover, the severity of pain was significantly lower in groups that received remifentanil in the cold and combination groups when compared with the control group. The incidence and severity of pain from the propofol injection in the combination group was significantly lower than that in the remifentanil and cold groups. Conclusions: The combination of cold propofol and pretreatment with remifentanil more effectively reduced the incidence of pain upon the injection of propofol than either treatment alone. (Korean J Anesthesiol 2010; 59: 305-309)

Background Similar to lipid emulsion propofol, microemulsion propofol also causes a high incidence of pain during intravenous injection. Various methods have been used to minimize the incidence and severity of pain on injection of lipid emulsion propofol. In this study, we investigated the effect of a lidocaine mixture on pain induced by microemulsion propofol injection, and sought to determine the optimal dose of lidocaine that could reduce pain on injecting a propofol-lidocaine mixture. Methods One hundred sixty (n = 160) patients of American Society of Anesthesiologists physical status class I or II were randomly allocated to four groups: Group A, control; Group B, 20 mg lidocaine; Group C, 30 mg lidocaine; Group D, 40 mg lidocaine. In each patient, pain on microemulsion propofol solution injection was graded as none, mild, moderate, or severe. Results The incidence of pain in groups A, B, C, and D was 97.5%, 80%, 65%, and 50%, respectively. Increasing the lidocaine dose significantly reduced pain (P < 0.05). One patient in Group D (2.5%) had moderate to severe pain, which was significantly lower than groups B (42.5%) and C (32.5%) (P < 0.05). Conclusions The lidocaine and propofol mixture is effective in alleviating pain associated with microemulsion propofol injection. Within this dose range and in this patients population, increasing lidocaine dosage significantly reduced pain during injection of microemulsion propofol.

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 μg/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. (Korean J Anesthesiol 2010; 58: 435-439)

We have compared iontophoretically and locally applied lidocaine for relief of pain on propofol injection. Pain was assessed on insertion of a 20-gauge i.v. cannula and at 10-s intervals for 30 s after injection of propofol. Pain scores on cannulation were significantly less in the iontophoresis group (median 1.1) than in the sham (control) group (median 2.8) (P0.005). Pain after injection of propofol was significantly reduced at 10 (P0.002), 20 (P0.001) and 30 s (P0.001). We conclude that iontophoretically applied lidocaine decreased the pain of cannulation and propofol injection.

Background and Aims: Propofol (2, 6-di-isopropylphenol) used for the induction of anaesthesia often causes mild to severe pain or discomfort on injection. We designed this double-blind study to compare the efficacy of methylprednisolone and lignocaine in reducing the pain of propofol injection in patients scheduled for cardiac surgery. Methods: A total of 165 adult patients, scheduled for elective cardiac surgery, were divided into three groups: saline (group S, n = 55), lignocaine 20 mg (Group L, n = 55) and methylprednisolone 125 mg diluted into 2 ml of distilled water (Group MP, n = 55). Drugs were administered after tourniquet application and occlusion was released after 1 min and 1/4 th of the total dose of propofol (2 mg/kg) was administered at the rate of 0.5 ml/s. Pain on propofol injection was evaluated by four-point verbal rating scale. Statistical methods used included Student′s t-test and Chi-square test/Fisher′s exact test. Results: The overall incidence of pain was 70.9% in the saline group, 30.9% in the lignocaine group and 36.4% in the methylprednisolone group. The intensity of pain was significantly less in patients receiving methylprednisolone and lignocaine than those receiving saline (P < 0.012). Conclusion: Pre-treatment with intravenous methylprednisolone was found to be as effective as lignocaine in reducing propofol injection-induced pain.

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 μg/kg or lidocaine 20mg plus remifentanil 0.3 μg/kg as pretreatment, followed by injection of 5mL 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.

BACKGROUND We hypothesized that the duration of electrocerebral (electroencephalogram, EEG) silence after bolus injection of propofol, a highly lipid soluble anesthetic drug, during transient cerebral hypoperfusion, will be directly related to the time taken by the bolus of drug to transit the cerebral circulation. METHODS We randomly divided 24 New Zealand White rabbits into two propofol volume groups: 0.5 and 0.8 mL groups. In each group, 12 animals received two intracarotid injections of 1% propofol: the first injection was made under normal physiological conditions and the second injection during cerebral hypoperfusion produced by bilateral carotid occlusion and IV bolus injection of adenosine and esmolol. We determined the duration of electrocerebral silence and the transit time of propofol emulsion under both cerebral circulation conditions. The transit time was measured by videomicroscopy through an implanted cranial window. RESULTS Cerebral hypoperfusion increased transit time with both low (2.3 +/- 0.7 to 55.7 +/- 21.4 s, n = 12, P < 0.0001) and high (2.2 +/- 0.6 to 62.5 +/- 31 s, n = 12, P < 0.0001) bolus volumes. The duration of electrocerebral silence during cerebral hypoperfusion was a function of the transit time with low (electrocerebral silence s = 152 + 2.3 x transit time, n = 12, r = 0.73, P = 0.007) and high (electrocerebral silence s = 186 + 3.2 x transit time, n = 12, r = 0.68, P = 0.02) bolus volumes. CONCLUSION These results suggest that manipulation of the transit time of highly lipid-soluble drugs profoundly enhances the effect site delivery.

Flurbiprofen axetil emulsion (FA), a prodrug of nonsteroidal anti-inflammatory drugs (NSAIDs) that is widely used for perioperative pain relief in Japan, has been effective for reducing propofol injection pain, but the mechanism is unclear. The purpose of this study was to test the hypothesis that the reduction of propofol injection pain by FA may be attributed to a decrease in free propofol concentration.Diprivan (propofol emulsion; Dipri; AstraZeneca, Cheshire, UK) and Propofol-Lipuro (Lipuro; B. Braun, Melsungen, Germany) were used. A randomized double-blind study was performed to compare pain on injection with six kinds of propofol solution: plain Dipri, a 3 : 1 (v/v) mixture of Dipri and saline (Dipri-S), a 3 : 1 mixture of Dipri and FA (Dipri-FA), plain Lipuro, a 3 : 1 mixture of Lipuro and saline (Lipuro-S), and a 3 : 1 mixture of Lipuro and FA (Lipuro-FA). Three hundred patients (American Society of Anesthesiologists [ASA] physical status [PS] I-II) scheduled for elective surgery received one of these six propofol emulsions (n = 50, each group). Injection pain was evaluated every 10 s after the start of a 1-min infusion of up to 2 mg x kg(-1) propofol. We also measured the in vitro free propofol concentrations of the propofol preparations that we tested (n = 5, each).The mixture of FA with propofol decreased the incidence of injection pain, compared with plain propofol, for Lipuro (P0.01) but not for Dipri. The free propofol concentration in each emulsion in vitro was also decreased by mixing the propofol with saline or FA. The incidence of pain was reduced in a free-propofol concentration-dependent manner (R(2) = 0.926).The findings suggest that the reduction of propofol injection pain by FA may be explained, at least in part, by a reduction in the free propofol concentration.

Pain is a well known complication of propofol injection. Many methods are described to reduce it but often empirical ways are used. In this study we attempt to determine the effects of premixing propofol with lidocaine or to preinjecting lidocaine in a hand vein in combination with using a tourniquet before we applicated propofol. Our study shows that both ways are able to reduce the injection pain but premixing with lidocaine 0.05% is less effective than giving a bolus of lidocaine before the propofol injection.

The authors evaluated adverse effects of intracarotid propofol injection during a Wada test and their risk factors in 58 patients. Nineteen patients had an adverse effect, mostly in patients receiving more than 10 mg. For patients older than age 55 years or those requiring an injection dose greater than 20 mg to produce hemiplegia, propofol should be injected slowly and patients monitored for excitatory movements.

A randomised, controlled, single-blind study was performed on 100 patients to investigate a new method of reducing pain on propofol injection. Aspiration of 2 ml of the patient's blood into a syringe of propofol immediately before injection was compared with the addition of lignocaine 20 mg or normal saline 2 ml to the propofol before injection. The addition of blood was significantly more effective in reducing pain on injection than the addition of saline (p < 0.001), but was not significantly more effective than the addition of lignocaine.

We hypothesized that the concentration of propofol in the aqueous phase may be the most important variable responsible for the pain experienced during injection of the drug. The concentration of propofol in the aqueous phase (18.57 micrograms/mL) can be decreased by increasing the fat content of the solvent. To test this hypothesis, 36 patients were randomly allocated to one of three groups, each receiving a different formulation of propofol. Group A received 20 mL of propofol alone in a commercial preparation (Diprivan(R) with 10 mL of saline); Group B, 20 mL of propofol to which 5 mL of long-chain triglyceride (LCT) fat emulsion and 5 mL of saline and been added; and Group C, 20 mL of propofol and 10 mL of LCT fat emulsion. The propofol emulsion was injected over 30-60 s into a dorsal vein of the hand. Patients reported pain during injection as none, mild, moderate, or severe (almost intolerable). In Group A, 8 of 12 patients reported moderate or severe pain upon injection whereas in Group C only mild pain was reported by 6 of 12 patients. Our results suggest that a smaller concentration of propofol in the aqueous phase of the emulsion reduces pain on injection. With the addition of more lipid (10 mL), a higher percentage of propofol is absorbed by fat particles. If solvents that permit a smaller concentration of the drug in the aqueous phase of oil-in-water emulsions were used for propofol and other drugs that cause pain on injection, pain would be reduced and patient satisfaction may be increased.

Propofol causes pain or discomfort on injection in 28%-90% of patients. A number of techniques have been tried for minimizing propofol-induced pain with variable results. We compared the efficacy of butorphanol and lidocaine for prevention of propofol-induced pain. One-hundred-fifty ASA I-II adults, undergoing elective surgery were randomly assigned into 3 groups of 50 each. Group I (NS) received normal saline, Group II (L) received lidocaine 2% (40 mg), and Group III (B) received butorphanol 2 mg. All patients received pretreatment solutions made in 2 mL with normal saline administered over 5 s. One min after pretreatment patients received one-fourth of the total calculated dose of propofol (2.5 mg/kg) over 5 s. Assessment of pain with IV propofol was done by using a four-point scale: 0 = no pain, 1 = mild pain, 2 = moderate pain and 3 = severe pain at the time of propofol injection. In the control Group 39 (78%) patients had pain during propofol injection as compared to 21 (42%) and 10 (20%) in the lidocaine and butorphanol groups, respectively (P < 0.05). Butorphanol was the most effective. We therefore suggest the IV pretreatment with butorphanol 2 mg for attenuation of pain associated with propofol injection.

The effects of nonsteroidal antiinflammatory drugs (NSAIDs) on pain from propofol injection are controversial, partially because NSAIDs themselves cause injection pain. We evaluated the effects of flurbiprofen axetil (LFP), a prodrug of an NSAID, on pain induced by intravenous propofol injection, because LFP produces little pain on injection.A randomized, double-blind, controlled trial was undertaken in patients who were assigned to one of three groups ( n = 50 in each). Patients received either 5 ml of saline followed approximately 10 min later by propofol mixed with 0.4 ml of saline, LFP (50 mg, 5 ml) i.v. followed by propofol mixed with 0.4 ml of saline, or 5 ml of saline followed by propofol mixed with lidocaine (40 mg, 0.4 ml). Verbal rating scores for injection pain were assessed every 10 s during propofol administration at a rate of 0.05 mg.kg(-1).s(-1).None of the patients complained of pain during injection of LFP or saline. Admixture of lidocaine, but not of LFP, significantly reduced the incidence of pain and the severity of pain scores during propofol injection ( P = 0.0017 and P0.001, respectively).Lidocaine, but not LFP, is effective for controlling pain induced by propofol injection. This result suggests that NSAIDs have little effect on pain from propofol injection.

Background: Intravenous injection of lipid emulsion propofol induces a considerable degree of pain and the most preferred treatment suggested is pretreatment with intravenous lignocaine to alleviate such pain. The present study was designed to evaluate whether addition of metoclopramide to lignocaine offers any advantage over lignocaine alone as a pretreatment in prevention of pain following propofol injection. Methods: In this prospective, randomized, double-blind controlled study, 60 patients were randomized to receive either lignocaine (group A) or lignocaine with metoclopramide (group B) intravenously as a pretreatment before injection of propofol. Pain due to injection of propofol was assessed with a four point categorical verbal rating pain scale. The incidence and magnitude of pain was compared between the two groups. Results: There was no statistically significant difference in the perceived intensity of pain between the two groups at different time points after administration of propofol. The incidence of moderate pain was 23.3% in group A and 20% in group B (p = 0.211); 26.7% patients in group A and 43.3% patients in group B had no pain during propofol administration (p = 0.116). Conclusions: Addition of metoclopramide to lignocaine does not have additional advantage over lignocaine alone in alleviating the pain of emulsified propofol injection.

To determine whether epidural lidocaine reduces the severity of propofol injection pain compared with iv lidocaine.A prospective, randomized double-blind clinical study was conducted in 120 female patients scheduled for elective gynecological laparotomy. A lumbar epidural catheter and an iv catheter placed in the cephalic vein of the non-dominant hand were used in all patients. Patients of the control group (Group C) were given epidural normal saline followed by iv normal saline then iv propofol. Patients of Group E were given epidural 2% lidocaine (0.08 mL.cm(-1)) followed by iv normal saline and then propofol. Patients of Group V were given epidural normal saline followed by iv 2% lidocaine (0.05 mL.kg(-1)) then propofol. Pain was scored as no pain=0, minimal pain=1, moderate pain=2, severe pain=3.The pain scores, in group E; 1 (0-2) and group V; 2 (0-2), were significantly lower than in group C; 2 (1-3); median (25th-75th percentile) (P0.001). There was no difference in pain score between groups E and V The plasma lidocaine concentration 15 min after epidural lidocaine was 2.74 +/- 0.54 microg.ml(-1), compared with 1.54 +/- 0.31 microg.mL(-1) at three minutes after iv lidocaine.Epidural and iv lidocaine equally reduced the severity of propofol injection pain despite higher lidocaine plasma concentrations in epidurally administered lidocaine.

An experimental study of platelet aggregation was performed in 22 male Landrace x Large-White crossbred pigs treated with propofol at different doses, to compare the results of optical aggregometry with those of the PFA-100 (Dade Int., Miami, FL, USA), a new platelet function analyzer. Platelet aggregation was analyzed in basal blood samples by both methods, after which the pigs were divided into three groups: G1, anaesthetic induction with propofol (2 mg/kg intravenously (i.v.)); G2, anaesthetic induction with propofol (2 mg/kg i.v.), followed by a second dose of 1.5 mg/kg; and G3, anaesthetic induction with propofol (2 mg/kg i.v.), followed by 1 h of continuous i.v. infusion at 13 mg/kg/h. Four minutes after propofol injection, blood samples were again taken from each group and studied by both methods. In groups G2 and G3, both methods showed reduced platelet aggregation, while in group G1 neither evidenced an anti-aggregating effect of propofol. Under our experimental conditions: (1) the propofol effect on platelet aggregation depends on the plasma concentration; (2) the results obtained with the two methods are comparable; (3) PFA-100 may provide an alternative to optical aggregometry for detecting the effects of anaesthetic agents ex vivo.

The hypothesis behind the present study was that remifentanil produces greater haemodynamic stability during rigid bronchoscopy than does the conventional propofol injection technique.