***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Summary We studied the  intubating conditions , haemodynamic and endocrine changes  following tracheal intubation during sevoflurane anaesthesia  guided by Bispectral Index ( BIS ) monitoring in 40 children who received either remifentanil 1 µg.kg−1 ( group R ) or saline 1 ml.kg−1 ( group S ) .  Acceptable intubating conditions were found in all patients in group R ( n = 20 ) , compared to only 12 patients in group S ( p = 0.002 ) . There were no intergroup differences in heart rate , systolic blood pressure and plasma concentrations of epinephrine and norepinephrine at any time point and changes in haemodynamic variables throughout the study period were moderate . Titration of sevoflurane delivery to a target BIS of 35 ± 5 led to almost equal end‐tidal sevoflurane concentrations in either group and remifentanil did not affect the BIS . There were no side‐effects in either group that required intervention . Intubating conditions  during sevoflurane anaesthesia in children were found to be improved by a single bolus dose of remifentanil 1 µg.kg−1 BACKGROUND We studied 120 children aged 2 - 7 yr in a prospect i ve , r and omized , assessor-blinded fashion to define the optimal rocuronium dose which provides a 95 % probability of acceptable intubation conditions ( ED95TI ) during inhalation induction with sevoflurane . METHODS After inhalation induction with 8 % sevoflurane in 60 % nitrous oxide and 40 % oxygen , and loss of the eyelash reflex , we administered rocuronium ( 0.1 , 0.15 , 0.22 , 0.3 , or 0.6 mg kg-1 ) or placebo . We quantified neuromuscular function by stimulation of the ulnar nerve at 0.1 Hz to produce contraction of the adductor pollicis muscle using accelerometry . Intubation conditions were assessed 2 min after test drug injection . The optimal rocuronium dose was defined as the lowest dose , which allowed acceptable intubation conditions in 95 % of children ( ED95TI ) . RESULTS Two minutes after injection of placebo or rocuronium , intubation conditions were acceptable in 35 , 45 , 80 , 90 , 95 , and 100 % of children , respectively . Rocuronium 0.07 [ CI 0.02 - 0.11 ] , 0.24 [ 0.19 - 0.31 ] , and 0.29 [ 0.23 - 0.38 ] mg kg-1 provided 50 , 90 , and 95 % probability of acceptable intubating conditions . When thumb acceleration was depressed by 50 % or more , intubating conditions were considered acceptable in 97 % of children . Recovery of the train-of-four ratio to 0.8 averaged 12 ( 7 ) , 16 ( 7 ) , 24 ( 7 ) , 24 ( 8) , and 50 ( 22 ) min after the respective dose of rocuronium . CONCLUSIONS During inhalation induction with 8 % sevoflurane in 60 % nitrous oxide , rocuronium 0.29 mg kg-1 ( ED95 ) optimizes intubation conditions for surgery of short duration BACKGROUND : Intubation without the use of muscle relaxants in children is frequently done before IV access is secured . In this r and omized controlled trial , we compared intubating conditions and airway response to intubation ( coughing and /or movement ) after sevoflurane induction in children at 2 and 3 min after the administration of intranasal remifentanil ( 4 mcg/kg ) or saline . METHODS : One hundred eighty-eight children , 1–7-yr old , were studied .  Nasal remifentanil ( 4 mcg/kg ) or saline was administered 1 min after an 8 % sevoflurane N2O induction . The sevoflurane concentration was then reduced to 5 % in oxygen , and ventilation assisted/controlled . An anesthesiologist blinded to treatment assignment used a vali date d score to evaluate the conditions for laryngoscopy and response to intubation . Blood sample s for determination of  remifentanil blood concentrations were collected from 17 children at baseline , 2 , 3 , 4 , and 10 min after nasal administration of remifentanil . RESULTS : Good or excellent intubating conditions were achieved at 2 min ( after the remifentanil bolus ) in 68.2 % and at 3 min in 91.7 % of the children who received intranasal remifentanil versus 37 % and 23 % in children who received placebo ( P < 0.01 ) . The mean remifentanil plasma concentrations ( ±sd ) at 2 , 3 , 4 , and 10 min were 1.0 ( 0.60 ) , 1.47 ( 0.52 ) , 1.70 ( 0.46 ) , and 1.16 ( 0.36 ) ng/mL , respectively . Peak plasma concentration was observed at 3.47 min . There were no complications associated with the use of nasal remifentanil . CONCLUSIONS : Nasal administration of remifentanil produces good-to-excellent intubating conditions in 2–3 min after sevoflurane induction of anesthesia Tracheal intubating conditions were assessed in 112 children after induction of anaesthesia with propofol and remifentanil 1.0 , 2.0 or 3.0 µg.kg−1 . Subjects in a control group were given propofol and mivacurium 0.2 mg.kg−1 . Haemodynamic and respiratory parameters were recorded . Plasma catecholamine levels were measured in a subgroup of 40 children .  Intubating conditions were acceptable in 14/28 ( 50 % ) , 18/26 ( 69 % ) and 22/27 ( 82 % ) in those subjects given remifentanil 1.0 , 2.0 or 3.0 µg.kg−1 , respectively , and in 27/28 ( 96 % ) of the control group . Intubating conditions in subjects given remifentanil 3.0 µg.kg−1 were better than in those given remifentanil 1.0 µg.kg−1 ( p < 0.05 ) . There were no significant differences in intubating conditions between those given remifentanil 3.0 µg.kg−1 and the control group . Systolic blood pressure and heart rate increased in response to tracheal intubation in subjects given remifentanil 1.0 µg.kg−1 and in the control group ( p < 0.05 ) . Time to resumption of spontaneous respiration was prolonged in subjects given remifentanil 3.0 µg.kg−1 ( p < 0.001 ) . In conclusion , remifentanil 2 µg.kg−1 provides acceptable intubating conditions and haemodynamic stability without prolonging the return of spontaneous respiration Background : Sevoflurane inhalation induction of anaesthesia is widely used in paediatric anaesthesia . We have found that this method is frequently associated with epileptiform electroencephalogram ( EEG ) in adults , especially if controlled hyperventilation is used IMPLICATION S Supplementing a sevoflurane induction of anesthesia in children with IV  lidocaine  2 mg/kg can suppress cough after tracheal intubation and thus improve intubating conditions . In addition , lidocaine minimizes blood pressure fluctuations after tracheal intubation BACKGROUND Remifentanil is known to cause bradycardia and hypotension . We aim ed to characterize the haemodynamic profile of remifentanil during sevoflurane anaesthesia in children with or without atropine . METHODS Forty children who required elective surgery received inhalational induction of anaesthesia using 8 % sevoflurane .  They were allocated r and omly to receive either atropine , 20 microg kg(-1 ) ( atropine group ) or Ringer 's lactate ( control group ) after 10 min of steady-state 1 MAC sevoflurane anaesthesia ( baseline ) . Three minutes later ( T0 ) , all children received remifentanil 1 microg kg(-1 ) injected over a 60 s period , followed by an infusion of 0.25 microg kg(-1 ) min(-1 ) for 10 min then 0.5 microg kg(-1 ) min(-1 ) for 10 min . Haemodynamic variables and echocardiographic data were determined at baseline , T0 , T5 , T10 , T15 and T20 min . RESULTS Remifentanil caused a significant decrease in heart rate compared with the T0 value , which was greater at T20 than T10 in the two groups : however , the values at T10 and T20 were not significantly different from baseline in the atropine group . In comparison with T0 , there was a significant fall in blood pressure in the two groups . Remifentanil caused a significant decrease in the cardiac index with or without atropine .  Remifentanil did not cause variation in stroke volume ( SV ) . In both groups , a significant increase in systemic vascular resistance occurred after administration of remifentanil . Contractility decreased significantly in the two groups , but this decrease remained moderate ( between -2 and + 2 sd ) . CONCLUSION Remifentanil produced a fall in blood pressure and cardiac index , mainly as a result of a fall in heart rate . Although atropine was able to reduce the fall in heart rate , it did not completely prevent the reduction in cardiac index BACKGROUND The aim of our study was to determine the optimal dose of propofol preceded by fentanyl for successful tracheal intubation and to see its effectiveness in blunting pressor response in children aged 3 - 10 years . METHODS This prospect i ve , double blind , r and omized study was conducted on 60 ASA grade I and II children , between 3 and 10 years undergoing elective surgery who were divided into three groups of 20 each . The children received different doses of propofol ( group I , 2.5 mg x kg(-1 ) ; group II , 3.0 mg x kg(-1 ) ; group III , 3.5 mg x kg(-1 ) ) preceded by a fixed dose of fentanyl ( 3.0 microg x kg(-1 ) ) 3 min earlier . The tracheal intubating conditions were grade d based on scoring system devised by Helbo-Hensen et al. with Steyn modification which includes five criteria ; ease of laryngoscopy , degree of coughing , position of vocal cords , jaw relaxation , and limb movement and grade d on a 4-point scale . Heart rate ( HR ) , mean arterial pressure ( MAP ) , and oxygen saturation changes were also noted . RESULTS Tracheal intubating conditions were acceptable in 25 % of the patients in group I , while significantly higher ( P < 0.001 ) in group II ( 80 % ) and in group III ( 90 % ) . The pressor response was not effectively blunted in group I ( 17 % increase in HR ) , while effectively blunted in groups II and III . A fall in cardiac output was seen in group III indicated by a decrease in MAP ( 16 % ) and HR ( 11 % ) . No airway complications were noted . CONCLUSIONS Propofol 3 mg x kg(-1 ) ( group II ) preceded by fentanyl 3 microg x kg(-1 ) is the optimal dose combination in our study . It provides acceptable intubating conditions in 80 % patients , blunts pressor response to intubation without significant cardiovascular depression BACKGROUND Drug effect lags behind the blood concentration . The goal of this investigation was to determine the time course of plasma concentration and the effects of propofol demonstrated by electroencephalogram or blood pressure changes and to compare them between elderly and young or middle-aged patients . METHODS A target-controlled infusion was used to rapidly attain and maintain four sequentially increasing , r and omly selected plasma propofol concentrations from 1 to 12 microg/ml in 41 patients aged 20 - 85 yr . The target concentration was maintained for about 30 min .  Bispectral index ( BIS ) , spectral edge frequency , and systolic blood pressure ( SBP )  were used as measures of propofol effect . Because the time courses of these measures following the started drug infusion showed an exponential pattern , the first-order rate constant for equilibration of the effect site with the plasma concentration ( k(eO ) ) was estimated by fitting a monoexponential model to the effect versus time data result ing from the pseudo-steady-state propofol plasma concentration profile . RESULTS The half-times for the plasma-effect-site equilibration for BIS were 2.31 , 2.30 , 2.29 , and 2.37 min in patients aged 20 - 39 , 40 - 59 , 60 - 69 , and 70 - 85 yr , respectively ( n = 10 or 11 each ) . The half-times for SBP were 5.68 , 5.92 , 8.87 , and 10.22 min in the respective age groups . All were significantly longer than for BIS ( P < 0.05 ) . The  propofol concentration at half of the maximal decrease of SBP was significantly greater ( P < 0.05 ) in the elderly than in the younger patients . CONCLUSIONS The effect of propofol on BIS occurs more 
    Output:
    
No serious adverse events were reported with these combinations