***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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    Input: Background Adverse drug reactions ( ADRs ) are an important cause of harm in children . Current data are incomplete due to method ological differences between studies : only half of all studies provide drug data , incidence rates vary ( 0.6 % to 16.8 % ) and very few studies provide data on causality , severity and risk factors of pediatric ADRs . We aim ed to determine the incidence of ADRs in hospitalized children , to characterize these ADRs in terms of type , drug etiology , causality and severity and to identify risk factors . Methods We undertook a year-long , prospect i ve observational cohort study of admissions to a single UK pediatric medical and surgical secondary and tertiary referral center ( Alder Hey , Liverpool , UK ) . Children between 0 and 16 years 11 months old and admitted for more than 48 hours were included . Observed outcomes were occurrence of ADR and time to first ADR for the risk factor analysis . Results A total of 5,118 children ( 6,601 admissions ) were included , 17.7 % of whom experienced at least one  ADR . Opiate analgesics and drugs used in general anesthesia ( GA ) accounted for more than 50 % of all drugs implicated in ADRs . Of these ADRs , 0.9 % caused permanent harm or required admission to a higher level of care . Children who underwent GA were at more than six times the risk of developing an ADR than children without a GA ( hazard ratio ( HR ) 6.40 ; 95 % confidence interval ( CI ) 5.30 to 7.70 ) . Other factors increasing the risk of an ADR were increasing age ( HR 1.06 for each year ; 95 % CI 1.04 to 1.07 ) , increasing number of drugs ( HR 1.25 for each additional drug ; 95 % CI 1.22 to 1.28 ) and oncological treatment ( HR 1.90 ; 95 % CI 1.40 to 2.60 ) . Conclusions ADRs are common in hospitalized children and children who had undergone a GA had more than six times the risk of developing an ADR . GA agents and opiate analgesics are a significant cause of ADRs and have been underrepresented in previous studies . This is a concern in view of the increasing number of pediatric short-stay surgeries CONTEXT Corticosteroids are commonly given to children undergoing tonsillectomy to reduce postoperative nausea and vomiting ; however , they might increase the risk of perioperative and postoperative hemorrhage . OBJECTIVE To determine the effect of dexamethasone on bleeding following tonsillectomy in children . DESIGN , SETTING , AND PATIENTS A multicenter , prospect i ve , r and omized , double-blind , placebo-controlled study at 2 tertiary medical centers of 314 children aged 3 to 18 years undergoing tonsillectomy without a history of bleeding disorder or recent corticosteroid medication use and conducted between July 15 , 2010 , and December 20 , 2011 , with 14-day follow-up . We tested the hypothesis that dexamethasone would not result in 5 % more bleeding events than placebo using a noninferiority statistical design . INTERVENTION A single perioperative dose of dexamethasone ( 0.5 mg/kg ; maximum dose , 20 mg ) , with an equivalent volume of 0.9 % saline administered to the placebo group . MAIN OUTCOME MEASURES Rate and severity of posttonsillectomy hemorrhage in the 14-day postoperative period using a bleeding severity scale ( level I , self-reported or parent-reported postoperative bleeding ; level II , required inpatient admission for postoperative bleeding ; or level III , required reoperation to control postoperative bleeding ) . RESULTS One hundred fifty-seven children ( median [ interquartile range ] age , 6 [ 4 - 8 ] years ) were r and omized into each study group , with 17 patients ( 10.8 % ) in the dexamethasone group and 13 patients ( 8.2 % ) in the placebo group reporting bleeding events . In an intention-to-treat analysis , the rates of level I bleeding were 7.0 % ( n = 11 ) in the dexamethasone group and 4.5 % ( n = 7 ) in the placebo group ( difference , 2.6 % ; upper limit 97.5 % CI , 7.7 % ; P for noninferiority = .17 ) ; rates of level II bleeding were 1.9 % ( n = 3 ) and 3.2 % ( n = 5 ) , respectively ( difference , -1.3 % ; upper limit 97.5 % CI , 2.2 % ; P for noninferiority < .001 ) ; and rates of level III bleeding were 1.9 % ( n = 3 ) and 0.6 % ( n = 1 ) , respectively ( difference , 1.3 % ; upper limit 97.5 % CI , 3.8 % ; P for noninferiority = .002 ) . CONCLUSIONS Perioperative dexamethasone administered during pediatric tonsillectomy was not associated with excessive , clinical ly significant level II or III bleeding events based on not having crossed the noninferior threshold of 5 % . Increased subjective ( level I ) bleeding events caused by dexamethasone could not be excluded because the noninferiority threshold was crossed . TRIAL REGISTRATION clinical trials.gov Identifier : NCT01415583 INTRODUCTION Postoperative vomiting occurs more frequently after  tonsillectomy  than any other commonly performed paediatric operation . Postoperative vomiting is also the commonest cause of morbidity and re-admission following  tonsillectomy .  We present a successful completed audit cycle and literature review on the subject . PATIENTS AND METHODS Data on the risk factors for postoperative vomiting , whether the patient vomited and details of the patient 's vomitus were collected prospect ively on consecutive patients and compared with a gold st and ard . Changes in practice were agreed and a second cycle performed . RESULTS Two cycles and a total of 107 patients were included in the audit . A significant reduction in vomiting from 27 % to 11 % was achieved following the introduction of routine use of intravenous dexamethasone during surgery . CONCLUSIONS This simple prospect i ve audit of paediatric post-tonsillectomy vomiting has result ed in a statistically significant reduction in vomiting which would appear to be due to use of intra-operative steroids Investigators from Bristol described a fentanyl‐ and diclofenac‐based analgesic technique for  tonsillectomy with low postoperative nausea and vomiting rates and low pain scores . This study compared the effectiveness of a modified Bristol technique with a codeine‐based regimen with respect to PONV and analgesia . Sixty‐five children , ASA 1‐2 , were r and omly assigned to either the Bristol group ( fentanyl 1–2 μg.kg−1 and diclofenac 1–2 mg.kg−1 ) or codeine group ( codeine 1.5 mg.kg−1 ) . All children received paracetamol 15 mg.kg−1 and dexamethasone 0.1 mg.kg−1 . Postoperative nausea and vomiting and pain scores were recorded hourly , and fitness for discharge was assessed at 4 h. The overall incidence of postoperative nausea and vomiting was 21 % with no difference between groups ( Bristol group 8/30 , codeine group 5/32 , p = 0.29 ) . Children in the Bristol group required analgesia earlier than those in the codeine group ( p < 0.005 ) , but maximum pain scores were not different ( Bristol group median ( IQR [ range ) 4.5 ( 3‐5 [ 0‐5 ] ) , codeine group 4.0 ( 2‐5 [ 1‐5 ] ) , p = 0.15 ) . Twenty‐three per cent of children were assessed as not fit for discharge at 4 h. The codeine‐based regimen may have a small advantage over the Bristol regimen , but neither technique seems ideally suited for a day‐case service without a longer period of observation BACKGROUND We conducted a factorial study of emesis prophylaxis with ondansetron ( OND ) , metoclopramide ( MET ) , and dexamethasone ( DEX ) . METHODS After informed parental consent , 240 children having adenotonsillectomy were r and omized to one of 15 combinations of OND ( 0 - 60 microg.kg(-1 ) ) , MET ( 0 - 400 microg.kg(-1 ) ) , and /or DEX ( 0 - 500 microg.kg(-1 ) ) . Using multivariable logistic regression , models were generated for the probability of emesis before discharge , after discharge and overall for 24 h. RESULTS Odds of emesis increased by a factor of three to four for children older than 7 years . Before discharge , odds of emesis decreased by factors of 0.29 for each 15 microg.kg(-1 ) of OND and 0.37 for each 100 microg.kg(-1 ) of MET . After discharge , odds of emesis decreased by a factor of 0.67 for each 125 microg.kg(-1 ) of DEX and increased by a factor of 3.5 for emesis before discharge . Over 24 h , odds of emesis decreased with OND , MET , and DEX ( ORs as above ) . A negative interaction between OND and MET was seen before discharge and over 24 h , reducing the efficacy of their combination . CONCLUSIONS We present novel study design and methods of analysis which are uniquely suited to studies of multiple interventions . Factorial design was a powerful tool , allowing simultaneous determination of dose-response relationships for three drugs and identifying a previously unreported negative interaction between OND and MET BACKGROUND Post-tonsillectomy morbidity statistics are obtained when patients present to hospital with complications . The two common morbidities are pain and haemorrhage . Hospital-recorded morbidity rates may be an underestimation , as some patients are treated by general practitioners and are therefore not included in hospital audits . METHODS Prospect i ve , cohort , question naire study to assess : the  post-tonsillectomy haemorrhage rate ( i.e. actual rate versus hospital recorded rate ) ; and the number of patients with post-operative pain and /or bleeding  who were treated with  antibiotics  by their general practitioner . RESULTS The  response rate was 76 per cent ( 70/92 ) . The actual rate of secondary haemorrhage was three times that noted in the hospital records ( 15.7 vs 5.7 per cent , respectively ) . Fifteen patients ( 21 per cent ) required extra analgesia after discharge . General practitioners prescribed antibiotics for pain alone in six patients ( 11 per cent ) . CONCLUSION The actual post-tonsillectomy haemorrhage rate is much higher than that recorded in hospital statistics . General practitioners differ in their treatment of post-tonsillectomy patients presenting with pain alone ; some prescribe antibiotics in addition to analgesia Edema contributes substantially to the postoperative discomfort and morbidity of adenotonsillectomy .  In a double-blind study , 58 children undergoing adenotonsillectomy were given a single intraoperative dose of either dexamethasone or saline . The steroid markedly affected the postoperative course in the first day after surgery . According to parental reports , the percentage of patients vomiting was reduced from 48 to 4 % . Severe throat pain was reported in 57 % of controls and only 20 % of dexamethasone patients . Twice as many steroid patients as controls tolerated some soft food on the first postoperative day . It appears that dexamethasone can greatly improve patient diet and comfort after adenotonsillectomy OBJECTIVES Investigation of the occurrence of  postoperative hemorrhage after tonsillectomy  and risk factors for these complications . STUDY DESIGN Prospect i ve National Audit with electronic web-based data collection from the National Health Service and independent hospitals in Engl and and Northern Irel and . METHODS Consenting patients undergoing tonsillectomy between July 2003 and September 2004 were included . A central data base of patient and surgical variables was developed for analysis of primary and secondary postoperative hemorrhage and development of risk models for tonsillectomy complications . RESULTS The Audit received data from 277 hospitals in Engl and and Northern Irel and on 40,514 patients . Analysis was conducted on 33,921 ( 84 % ) who gave consent . Over the whole Audit 1,197 ( 3.5 % ) postoperative hemorrhages were recorded . One hundred eighty-eight ( 0.6 % ) patients sustained a primary hemorrhage and 1,033 ( 3 % ) a secondary hemorrhage ( 24 had both ) . Elevated hemorrhage rates were observed in tonsillectomies performed using diathermy for dissection and hemostasis compared with cold steel dissection and ties for hemostasis . National guidance issued midway through the Audit influenced practice and reduced hemorrhage rates . Risk models for postoperative hemorrhage were developed incorporating the effect of the guidance . For hemorrhage , compared with the cold steel group , bipolar diathermy tonsillectomy had an odds ratio of 2.47 ( 1.81 - 3.36 ) , P < .0001 , and bipolar diathermy scissors tonsillectomy an odds ratio of 3.20 ( 2.09 - 4 
    Output:
    
The pooled analysis did not demonstrate a statistically significant increase in the risk of post-tonsillectomy haemorrhage with dexamethasone with/without NSAID use in children .