***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Background To analyze how lidocaine 40 mg mixed prevents injection pain of propofol affects the onset time of rocuronium , tracheal intubating conditions and intubation related hemodynamic changes . Methods This study consisted of 70 patients with an American Society of Anesthesiologists ( ASA ) physical status class 1 or 2 for general anesthesia . All the patients were r and omly allocated into two groups : propofol 2 mg/kg plus normal saline 2 ml ( Group C ) and propofol 2 mg/kg plus 2 % lidocaine 40 mg ( Group L ) . Each group was administrated intravenously during induction and the patient was intubated 1 minute after an injection of 0.6 mg/kg of rocuronium . The time at disappearance of the first twitch and intubation scores were recorded . Also , blood pressure and heart rate were measured at the baseline , after intravenous injection of propofol , before intubation , and at 0 , 1 , 2 , 3 and 5 minutes after intubation . Results There were no significant differences between group C and L ( P > 0.05 ) . Conclusions 40 mg of lidocaine mixed with propofol to prevent injection pain did not affect the onset time of rocuronium , intubating conditions and intubation related hemodynamic changes The aim of this study was to determine whether pretreatment with alkalinised lignocaine reduced the incidence and severity of pain during propofol injection . This prospect i ve , r and omised , double-blind study included 300 adult , American Society of Anesthesiologists physcial status I to II patients undergoing elective surgery . Patients were r and omly allocated to one of three groups : Group L received 0.05 ml/kg of 1 % lignocaine ( 5 ml normal saline + 5 ml 2 % lignocaine ) , Group A received 0.05 ml/kg alkalinised lignocaine ( 5 ml 2 % lignocaine + 1 ml 8.4 % NaHCO3 + 4 ml normal saline ) , and Group S , the control group , was given the same amount of normal saline ( NaCl 0.9 % ) . All drugs were given as a bolus over 20 seconds before propofol administration . A blinded research er assessed the patient 's pain level using a four-point scale . The pain score [ median ( range ) ] and the incidence of pain in Group A ( 6 % ) was significantly lower than in groups L ( 41 % ) and S ( 88 % , P < 0.001 ) . In addition , the pain score and the incidence of pain were found to be significantly different between Group L and Group S ( P < 0.001 ) . The incidence of moderate and severe pain were greater in Group S when compared with groups A and L ( P < 0.001 ) . Intravenous pretreatment with alkalinised lignocaine appears to be effective in reducing the pain during propofol injection Pain on injection , reported in 28 - 90 % of patients , is one of the most described side effects of the intravenous application of propofol . Many different approaches have been used in attempts to minimize propofol induced pain , with varied results . Using a r and omized , double-blind protocol design , the author-section pain following the administration of two different particle size formulations of propofol with or without lidocaine in 388 nonpremedicated ASA I-II adult patients scheduled for elective surgery under general anesthesia . Patients were allocated r and omly to receive either a small particle size lipid emulsion of propofol ( Anepol : average particle size 140.5 nm ) , or st and ard propofol ( Propofol : average particle size 193.3 nm ) , by dividing into 4 groups . Group 1 received 2 ml NaCl 0.9 % and Propofol , group 11 received 2 ml lidocaine 2 % and Propofol , group III received 2 ml NaCl 0.9 % and Anepol and group IV received 2 ml lidocaine 2 % and Anepol into a dorsal vein of the h and . Pain during propofol injection was evaluated over 5 - 10 seconds , until loss of conscious , using a four point scale . Sixty-seven patients ( 69.1 % ) complained of pain in group 1 , as compared with 50 % , 41.2 % and 39.2 % in group II , III and IV ( p < 0.05 ) . The reported severity of injection pain was not significantly different between the groups . The authors conclude that small particle size propofol causes less pain on injection than st and ard propofol BACKGROUND Propofol formulated with medium- and long-chain triglycerides ( MCT/LCT ) causes less pain on injection than st and ard Propofol , but the incidence of pain persists between 28 and 67 percent . Such a broad range begs the question so the authors wanted to clarify whether the addition of lidocaine to medium- and long-chain triglyceride emulsion propofol results in any clinical ly significant lessening of pain on injection . The authors conducted a r and omized , prospect i ve , double-blinded study to compare the injection pain felt following the administration of propofol-MCT/LCT ( Propofol-Lipuro ) to propofol-MCT/LCT plus 20 mg lidocaine for the induction of anesthesia . MATERIAL AND METHOD The present study included 270 non-premedicated ASA I-II adult patients scheduledfor elective surgery under general anesthesia . Patients were allocated r and omly into two groups to receive either propofol-MCT/LCT alone or propofol-MCT/LCT plus 20 mg lidocaine . The study solution was injected at 1 mL/second by one anesthesiologist and patients grade d any associated pain using a four-point scale . RESULTS The overall incidence of pain on injection was 31/133 ( 23 % ) in the propofol-MCT/LCT plus lidocaine group vs. 45/135 ( 33 % ) in the propofol-MCT/LCT alone group . The difference in the incidence of pain on injection between groups failed to achieve statistical significance ( p = 0.23 ) and no significant difference in intensity of pain between the two study groups occurred CONCLUSIONS The authors concluded that the addition of lidocaine ( 20 mg ) to the propofol-MCT/LCT does not significantly reduce the incidence or severity of the pain on injection BACKGROUND Propofol is commonly used for induction and maintenance of anesthesia , but pain at the site of intravenous injection is a clinical problem . We studied the effectiveness of local cooling and pretreatment with lidocaine for prevention of injection pain of propofol . METHODS A total of 226 adult patients scheduled to receive general anesthesia were assigned r and omly to four groups : a control group receiving no prophylactic intervention , a cooling group receiving topical cooling , a lidocaine group receiving 1 mg x kg(-1 ) lidocaine , and a lidocaine plus cooling group receiving topical cooling and 1 mg x kg(-1 ) lidocaine . A 20 gauge intravenous catheter was inserted into the peripheral vein at the radial side of the forearm . After prophylactic intervention had been performed , 1 - 2 mg x kg(-1 ) MCT/LCT propofol was injected . Patients were asked to grade the pain as none , mild , moderate , or severe . RESULTS The incidence of propofol-induced pain was significantly higher in the control group ( 39 % ) than in the other three groups ( 17 % in the cooling group , 16 % in the lidocaine group and 8 % in the lidocaine plus cooling group ) . However , there were no significant differences between the three groups with different prophylactic interventions . CONCLUSIONS The results suggest that cooling and pretreatment with lidocaine reduce the incidence of pain upon propofol injection BACKGROUND Pain on injection is a recognized adverse event ( AE ) with propofol , an agent used to induce general anesthesia in surgical patients .  Lidocame ( LID ) has been found efficacious in reducing pain on injection of propofol ; however , this type of pain may not be completely eliminated with LID . Metoclopramide ( MET ) is a dopamine receptor agonist with antiemetic and prokinetic properties used for the treatment of nausea and facilitation of gastric emptying in patients with gastroparesis . MET also has local anesthetic properties similar to those of LID . OBJECTIVE The aim of this study was to examine the effects of LID administered with 3 different doses of MET or saline on pain on injection of propofol in Japanese adults undergoing elective surgery . METHODS This r and omized , double-blind study was conducted at the Department of Anesthesiology , University of Tsukuba Institute of Clinical Medicine , Tsukuba , Japan . Japanese patients aged 20 to 67 years who were scheduled to undergo elective surgery were eligible for participation . Patients were r and omized to receive N administration of LID 40 mg + MET 2.5 , 5 , or 10 mg or saline . A rubber tourniquet was used to perform 1 minute of venous occlusion before administration of the study and control drugs , and then 25 % of the total calculated dose of propofol ( 2 mg/kg ) was injected into the dorsal vein of the h and through a 20-G N cannula at a rate of 1 mL/s . During a 10-second pause before the induction of anesthesia , patients were question ed by a blinded investigator about the pain intensity on injection . Pain intensity was assessed through the use of a 4-point verbal rating scale , with scores ranging from 0 ( no pain ) to 3 ( severe pain ) . Incidence and intensity of pain ( as assessed by mean pain scores ) were determined in each of the 4 study groups . Extrapyramidal reactions and injection-site AEs , including pain , edema , wheals , and inflammation occurring up to 24 hours after surgery were recorded by a blinded investigator . RESULTS The study enrolled 240 patients ( 126 men , 114 women ; mean [ SD ] age , 43 [ 13 ] years [ range , 20 - 67 years ] ; mean [ SD ] height , 160 [ 8 ] cm [ 133 - 181 cm ] ; mean [ SD ] body weight , 57 [ 10 ] kg [ range , 33 - 85 kg ] ) . There were 60 patients r and omized to each of the 4 study groups , which were comparable in distribution of demographic characteristics . Incidence of propofol-induced pain was significantly lower , but the intensity of pain was not less , in the groups that received LID/MET 40/5 or 40/10 ( both , 5 % ) compared with those who received LID/MET 40/2.5 or LID/saline ( 18 % and 20 % , respectively ) ( all , P < 0.05 ) . There were no reports of injection-site AEs or extrapyramidal reactions after injection of the control or study drugs in any of the study groups . CONCLUSION Among these 240 Japanese patients undergoing elective surgery , N administration of LID/MET 40/5 or 40/10 was associated with lower incidence , but not lower mean pain intensity scores , of pain on injection of propofol than LID/MET 40/2.5 or LID/saline before induction of anesthesia A r and omised , double‐blind , controlled trial was undertaken to compare three different methods of reducing pain during the intravenous injection of propofol . In 101 patients undergoing daycase surgery , verbal rating scores , for pain during injection of  propofol  were compared immediately after intravenous pretreatment with ketorolac 10 mg , lignocaine 10 mg or saline .  Neither pain during injection ( p = 0.129 ) , nor venous sequelae at 7 days postoperatively were significantly different between the three treatments . Pain during propofol injection remains a confounding clinical problem Background : Several commercial formulations of propofol are available . The primary outcome of this study was the required dose of propofol alone or combined with lidocaine to achieve induction of general anesthesia . Methods : This multicenter , double-blinded trial r and omized patients ( American Society of Anesthesiologists physical status I – III ) just before elective surgery with the use of a computer-generated list .  Three different propofol 1 % formulations — Diprivan ® ( Astra-Zeneca , Cheshire , United Kingdom ) , Propofol ® ( Fresenius-Kabi AG , Bad Homburg , Germany ) , and Lipuro ® ( B-Braun , Melshungen AG , Germany)—were compared with either placebo ( saline solution ) or lidocaine 1 % mixed to the propofol solution . Depth of anesthesia was automatically guided by bispectral index and by a computerized closed-loop system for induction , thus avoiding dosing bias . The authors recorded the total dose of propofol and duration of induction and the patient ’s discomfort through a behavioral scale ( facial expression , verbal response , and arm withdrawal ) ranging from 0 to 6 . The authors further evaluated postoperative recall of pain using a Visual Analog Scale . Results : Of the 227 patients enrolled , 217 were available for analysis . Demographic characteristics were similar in each group . Propofol ® required a higher dose for induction ( 2.2 ± 0.1 mg/kg ) than Diprivan ® ( 1.8 ± 0.1 mg/kg ) or Lipuro ® ( 1.7 ± 0.1 mg/kg ; P = 0.02 ) . However , induction doses were similar when propofol formulations were mixed with  lidoca 
    Output:
    
Currently available data from RCTs are sufficient to confirm that both lidocaine admixture and pretreatment were effective in reducing pain on propofol injection .
Furthermore , there were no significant differences of effect between the two techniques