percutaneous nephrolithotomy ( pcnl ) is considered as  gold standard for the management of patients with renal calculi . several investigations have focused on the impact of reduced percutaneous catheter size on post - operative pain , analgesic requirements and duration of cutaneous drainage . in pcnl surgery , analgesics like non - steroidal anti - inflammatory drugs and opioids have their own side - effects . infiltration of local anaesthetic from the renal capsule to the skin along the nephrostomy tract has been reported to relieve the initial post - operative pain . the aim of this study was to investigate and compare the efficacy of peritubal infiltration of two different local anaesthetics , bupivacaine 0.25% versus ropivacaine 0.25% administered under ultrasonic guidance for post - operative pain relief after pcnl and to assess the number of doses as well as total requirement of rescue analgesic in first 24 h of the post - operative period . a prospective randomised double - blind prospective comparative study was conducted from january 2012 to december 2012 in 100 american society of anaesthesiologists physical status i - iii adult patients posted for pcnl surgery after institutional ethics committee 's approval and informed consent . they were randomly divided into two equal groups with 50 patients in each group by closed envelope method . group b was bupivacaine group ( 0.25% bupivacaine infiltration ) , and group r was ropivacaine group ( 0.25% ropivacaine infiltration ) . patient 's inclusion criteria were 18 - 60 years of age , 35 - 85 kg weight having body mass index < 30 , renal stone size < 3.0 cm with a single nephrostomy tube ( 22 f ) and duration of surgery <3 h. patients having supracostal puncture , excessive bleeding and more than one puncture were excluded from the study . study drug was prepared by person blinded to the actual study and findings recorded by a third person . all patients were pre - medicated with intravenous ondansetron 8 mg , intravenous fentanyl of 2 g / kg and intravenous glycopyrrolate 0.04 mg / kg . balanced general anaesthesia was administered , induction done using thiopentone 5 - 6 mg / kg and intubation facilitated by succinylcholine 1.5 mg / kg . after endotracheal intubation , patients were maintained with o2/n2o with a muscle relaxant and isoflurane . after insertion of nephrostomy tube and before the extubation of inserted up to renal capsule under ultrasonographic ( micromaxx ultrasound from sonosite ) guidance along the nephrostomy tube at 6 oclock and 12 oclock positions . in group b , 20 ml of 0.25% bupivacaine and in group r , 20 ml of 0.25% ropivacaine was infiltrated ( 10 ml in each tract ) while gradually withdrawing the needle from renal capsule to the skin thereby infiltrating the renal capsule , perinephric fat , muscles , subcutaneous tissue and skin . patients were extubated and kept in post - anaesthesia care unit under observation for 24 h. during follow - up , patients were assessed for pain and side - effects by an independent observer blinded to the infiltration , immediately after extubation , half hourly for 2 h , every 2 hourly for the next 6 h and every 4 hourly until 24 h. the pain score was assessed using 0 - 10 point visual analogue scale ( vas ) at rest and dynamic visual analogue scale ( d - vas ) on deep breathing and coughing ( 0- no pain and 10 - maximum , unbearable pain ) . when vas score > 4 , the patient was administered intravenous tramadol 1.0 mg / kg slowly as a rescue analgesia , and the patient was reassessed . maximum 400 mg of tramadol was administered in initial 24 h. intravenous ondansetron wasgiven if there was nausea and vomiting . nausea was scored as grade 0 - 3 where 0 means none and 3 means severe nausea . time for first demand of rescue analgesic was noted to assess the duration of analgesia . number of doses of tramadol and total consumption of tramadol required in 24 h were noted . statistical analysis was performed using , statistical considering a hypothesis that after administration of peritubal local infiltration , the first demand of rescue analgesia was longer by 40% , with a power of 90% and an  error of 0.05 , the sample size was estimated as 50 patients in each group . continuous data were described as mean  standard deviation and categorical variables are given as number ( % ) . the demographic data regarding age , weight , sex , and duration of surgery were comparable and insignificant [ table 1 ] . vas ( at rest ) and d - vas ( during deep breathing and coughing ) were low in both groups in the post - operative period , but significantly lower in group r as compared with group b at 6 h and 8 h [ figures 1 and 2 ] . the mean time for first demand of analgesia was 10.54  2.24 h in group r and 7.91  1.96 h in group b ( p < 0.0001 ) . the mean number of analgesic demands required during initial 24 h was 2.27  0.49 in r group and 2.39  1.03 in group b ( p = 0.458 ) . the mean total consumption of tramadol in first 24 h was 122.2  29.01 mg in group r and 134.3  58.7 mg in group b ( p = 0.194 ) . the side - effects like nausea and vomiting were less and insignificant in both groups [ table 2 ] . mean visual analogue scale mean dynamic visual analogue scale comparison of rescue analgesic requirement and side - effects keyhole surgery has replaced open surgery in many surgical fields as it causes less pain and morbidity . in urology , pcnl is emerging as the surgery of choice in most of patients with renal calculi . placement of nephrostomy tube is the last step in pcnl surgery for good haemostasis and adequate drainage . the nephrostomy tube produces local inflammatory reaction which causes the post - operative pain and discomfort in pcnl . on - going studies aim at decreasing the post - operative pain and morbidity by reducing the size of the working percutaneous tract , a procedure referred to as a miniperc. even tubeless pcnl operations were done by some authors and they have reported decreased pain and analgesic requirements for selected patients . local anaesthetics can inhibit inflammatory and local sensitising responses by directly suppressing some phases of inflammation like neutrophil priming and by blocking some of the neuronal pathways , which are activated by inflammation involving protein kinase c and g protein - coupled receptors . haleblian et al . conducted a study on subcutaneous infiltration of 1.5 mg / kg of 0.25% bupivacaine versus saline after pcnl in 25 patients . their results showed reduced rescue analgesic requirement in bupivacaine group , but no significant difference in pain score was found in both groups . hence , it was hypothesised that the cause for pain after pcnl surgery , which requires nephrostomy tube , could result from structures beyond the skin puncture site like the renal capsule . dalela et al . performed pcnl under renal capsular block by infiltrating renal capsule with 2% lignocaine . he emphasised that most of pain during pcnl is felt at the time of dilatation of renal capsule and parenchyma as it is richly innervated by pain conducting neurons . in another study , aravantinos et al . performed pcnl in two stages in 24 patients . in 1 stage , 16-fr nephrostomy tube was placed after infiltrating skin site with 2% lignocaine for 1-week . in 2 stage , after infiltrating the nephrostomy tract with 2% lignocaine , dilatation of the tract was performed and stones were removed . performed a study for post - operative pain relief using 0.25% bupivacaine infiltration along the nephrostomy tract after pcnl under fluoroscopic guidance . they found lower pain scores and prolonged duration of analgesia in block group than the control group . compared 0.25% levobupivacaine infiltration plus intravenous paracetamol infusion , saline plus paracetamol infusion and 0.25% levobupivacaine plus saline infusion . they found lesser requirement of opioid ( meperidine ) , lower vas score , and shorter time to full mobilisation and higher patient satisfaction score in the levobupivacaine plus paracetamol group compared to other two groups . . infiltrated 30 ml of either 0.2% ropivacaine or saline into renal puncture site , nephrostomy tract and skin after pcnl . their results showed that vas at 6 h , time to first analgesic demand ( 8.4  0.6 h ) and total analgesic need were significantly lower in ropivacaine group , which correlates with previous studies . in our study , we have compared the efficacy of two different local anaesthetics that is , bupivacaine and ropivacaine for infiltration along the nephrostomy tract . we found the mean duration of analgesia to be average 10.54 h in group r and 7.91 h in group b. akerman et al . conducted a study on primary evaluation of local anaesthetic properties of ropivacaine and concluded that ropivacaine 0.25 - 1% was distinctly longer acting than bupivacaine on infiltration . they suggested that ropivacaine was less vasodilative than bupivacaine and capable of producing some vasoconstriction over a wide range of low concentrations , which may explain its longer duration of action . in our study , incidence of side - effects like nausea and vomiting were minimum and insignificant in both groups . the limitation of our study was that we included patients with single punctures with a single nephrostomy tube , thus being unable to evaluate the efficacy of our study when more than one puncture was involved . peritubal infiltration with local anaesthetics ropivacaine and bupivacaine under ultrasound guidance provides effective pain relief in the initial post - operative period ; however , duration of analgesia as denoted by demand to first rescue analgesic is prolonged with ropivacaine as compared with bupivacaine .
background and aim : percutaneous nephrolithotomy ( pcnl ) is a common for managing renal calculi . 
 pain in the initial post operatie period is relieved by infiltration of local anaesthetic around the nephrostomy tract . 
 we aimed to compare the analgesic efficacy of bupivacaine and ropivacaine.methods:a total of 100 adult patients undergoing elective pcnl  under balanced general anaesthesia 
 were randomly divided into bupivacaine group ( group b ) and ropivacaine group ( group r ) . 
 after completion of procedure , 23 g spinal needle was inserted at 6 and 12 oclock position under ultrasonic guidance up to renal capsule along the nephrostomy tube . 
 a volume of 10 ml of either 0.25% bupivacaine or 0.25% ropivacaine solution was infiltrated in each tract while withdrawing the needle . 
 post - operative pain was assessed using visual analogue scale ( vas ) and dynamic visual analogue scale ( d - vas ) for initial 24 h. intravenous tramadol was given as rescue analgesia when vas > 4 . 
 time to first rescue analgesic , number of doses and total amount of tramadol required in initial 24 h and side - effects were noted.results:visual analogue scale and d - vas at 6 h and 8 h in group b was significantly higher than group r. mean time to first rescue analgesia in group r was significantly longer than group b. mean number of doses of tramadol and total consumption of tramadol in 24 h was less in group r , though not statistically significant.conclusion:peritubal infiltration of 0.25% ropivacaine infiltration along the nephrostomy tract is more effective than 0.25% bupivacaine in alleviating initial post - operative pain after pcnl .