propofol is an intravenous ( iv ) anaesthetic drug used for induction and maintenance during anaesthesia .
in addition , the hyperdynamic cardiovascular response to the pain can precipitate adverse events in high - risk patients with a history of coronary artery disease and/or abnormal heart rhythm .
many factors appear to affect the incidence of pain , which include site of injection , size of vein , speed of injection , buffering effect of blood , temperature of propofol and concomitant use of drugs such as local anaesthetics and opiates .
corticosteroids are systemic anti - inflammatory agents , systemic analgesics and are known to block nociceptive c fibres when applied locally .
methylprednisolone is commonly used during cardiopulmonary bypass to reduce inflammatory response at doses of 10 - 30 mg / kg body weight .
methylprednisolone sodium succinate for injection is available in 40 mg , 125 mg , 500 mg and 1000 mg strengths .
the study was approved by the hospital ethical committee and written informed consent was obtained from all the patients . in this study , 165 patients between 21 and 60 years irrespective of sex belonging to the american society of anesthesiologists ( asa ) physical status i and ii undergoing elective cardiac surgery were included .
patients with allergy to propofol , lignocaine , anticipated difficult venous access , patients with cardiac conduction defects , congenital heart disease , low ejection fraction , haemodynamically instability , diabetes mellitus , chronic pain syndromes , convulsions , head injury and systemic fungal infections were excluded from the study .
this was an interventional , randomised , prospective , double - blind , parallel group study .
a 20-gauge cannula was placed into the largest vein on the dorsum of the left hand .
patients were randomly assigned to three groups of 55 patients each according to a computer - generated random number sequence .
group s patients received 2 ml of normal saline as a placebo ; group l patients received pre - treatment with lignocaine ( 20 mg of 2% solution diluted to 2 ml with distilled water ) , and group mp patients received pre - treatment with methylprednisolone sodium succinate ( 125 mg diluted into 2 ml of distilled water ) .
after limb elevation for 15 s , venous drainage was occluded by placing a tourniquet inflated to 40 mmhg . according to the experimental group ,
respective drug was injected , and the investigator was blinded to the content of the solution .
tourniquet was deflated after 1 min , and then 0.5 mg / kg of propofol ( long chain triglycerides lct ) was administered at the rate of 0.5 ml / s .
the intensity of pain on injection of propofol was assessed by a second anaesthesiologist who was unaware of the group to which the patient had been allocated .
assessment included standard questions asked to the patients about the comfort of the injection , verbal response and behavioural signs ( such as facial grimacing , arm withdrawal or tears from the eyes ) .
pain was graded using a four - point scale : 0 = no pain , 1 = mild pain ( pain reported only in response to questioning without any behavioural signs ) , 2 = moderate pain ( pain reported in response to questioning and accompanied by a behavioural sign or pain reported spontaneously without questioning ) and 3 = severe pain ( i.e. strong vocal response or response accompanied by facial grimacing , arm withdrawal or tears ) .
anaesthesia induction was continued with fentanyl 35 g / kg and midazolam 0.03 mg / kg intravenously .
the trachea was extubated and were assessed for pain , swelling or allergic reaction at the site of injection by a blinded anaesthesiologist .
considering previous studies , the incidence of propofol - induced pain was assumed as 80% and 50% reduction was considered significant .
based on the alpha value of 0.05 and a power value of 80% , our study required at least 41 patients per group .
comparison of age , sex , weight and asa between the three groups was obtained by student 's t - test .
categorical data are reported as numbers and percentages and are analysed using chi - square test or fisher 's exact test as appropriate .
there were no significant differences in demographic characteristics between the three groups [ table 1 ] .
no incidence of pain or discomfort was reported during the injection of pre - treatment solution in any group .
the overall incidence of pain was 70.9% ( 64.2%77.6% ) in the saline group , 30.9% ( 21.2%40.6% ) in the lignocaine group , and 36.4% ( 31.5%41.3% ) in the methylprednisolone group [ table 2 ] .
the incidence of pain was significantly less ( p < 0.012 ) in patients receiving drugs for pre - treatment than those receiving saline .
moderate to severe pain was observed in 3 ( 5.4% ) and 4 ( 7.3% ) patients in groups l and mp respectively as compared to 34 ( 62% ) patients in s group .
the difference in moderate to severe pain between the study groups ( l and mp ) was not statistically significant . incidence and severity of pain following propofol injection among groups
in this study , the incidence of pain during the injection of propofol in the lignocaine group was 30.9% , whereas in the methyl prednisolone group , it was 36.4% .
moderate to severe pain was reported in 5.4% of the patients in the lignocaine group whereas 7.3% was reported in the methyl prednisolone group .
there are very few studies on the use of pre - treatment with steroid - based drugs for the alleviation of pain on propofol injection .
the mechanism for propofol injection pain is unknown ; however it could be due to irritation of the endothelium , osmolality differences , unphysiological ph and the activation of pain mediators .
the immediate vascular pain on propofol injection is attributed to direct irritation of the drug by stimulating the venous nociceptive receptors or free nerve endings involving myelinated a fibres .
the delayed pain of injection has a latency of 1020 s mediated by activation of kallikrein  kinin system .
there are many strategies to reduce the incidence of pain on injection which include the following : pre - treatment with iv lignocaine , adding lignocaine to propofol , cooling or warming propofol , injection of propofol into a large vein , preadministration of 5-ht3 receptor antagonist , dexamethasone , hydrocortisone with or without tourniquet . among these studies ,
the most commonly accepted technique is the administration of lignocaine just before the injection of propofol .
corticosteroids are used routinely in cardiac surgery to attenuate the release of pro - inflammatory cytokines .
methylprednisolone is a commonly used steroid during cardiopulmonary bypass in our institute , so we choose methylprednisolone to test the efficacy in reducing pain on propofol injection .
a previous study found that 31% of patients felt pain ( p < 0.01 ) after dexamethasone pre - treatment and moderate to severe pain was noticed in 17.14% .
another study comparing lignocaine , pethidine and dexamethasone as pre - treatment found that 48% of the patients with dexamethasone pre - treatment had no pain .
the combination of lignocaine 20 mg and dexamethasone 6 mg with venous occlusion for 1 min was more effective than lignocaine 20 mg ( 34.3% ) or dexamethasone 6 mg ( 37.1% ) alone for pain control during propofol injection .
these results show an effective reduction in the incidence and severity of propofol injection pain after pre - treatment with dexamethasone .
pre - treatment with either 10 mg or 25 mg of hydrocortisone was associated with no significant reduction of propofol injection pain ( 66.66% and 94.44% respectively ) when compared to a placebo ( 94.44% ) .
it was administered 30 s before the administration of propofol , which may be a short contact time .
the incidence of pain was 70.9% in the group s whereas in those pre - treated with lignocaine and methylprednisolone , it was 30.9% and 36.4% , respectively .
these results show that there is a significant reduction in the propofol injection pain , and both lignocaine and methylprednisolone are equally effective .
there is a significant decrease in moderate to severe pain ( 5.4% and 7.3% in each l and mp group ) when compared with group s ( 62% ) .
the use of methylprednisolone should be individualised with due consideration to the cost - effectiveness and benefit to the patient .
the analgesic efficacy of methylprednisolone given as pre - treatment with propofol is as effective as lignocaine in preventing propofol - induced pain .
therefore , it can be administered before propofol in patients who require methylprednisolone for other indications .
 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 1/4th 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 . 
INTRODUCTION
METHODS
RESULTS
DISCUSSION
CONCLUSION
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