with the availability of newer and smaller endoscopes , the utilization of endoscopy to diagnose gastrointestinal disorders in children is increasing . pediatric upper gastrointestinal endoscopy ( ugie ) can be completed without sedation , by using intravenous sedation , or with general anesthesia [ 14 ] . various medication combinations have been used for pediatric sedation , including intravenous ketamine , propofol , midazolam , fentanyl , and pethidine . the goals of sedation are to ensure patient safety , provide analgesia and amnesia , control behavior during the procedure , enable successful completion of the procedure , and quickly return the patient to pretreatment level of consciousness .         in a developing country like thailand , pediatric ugie in addition , in provincial or community hospitals , general anesthesia in the main operating room remains the sedation plan of choice for pediatric ugie . at siriraj hospital , a world gastroenterology organization ( wgo ) endoscopy training center , there is a dedicated gastrointestinal endoscopy unit and dedicated anesthesiology service for the unit . over the years , we have observed a change in the trend of sedation for pediatric ugie towards intravenous sedation ( ivs ) technique [ 57 ] . this study , therefore , is done to review our sedation practice and to evaluate the clinical effectiveness of an anesthesiologist - administered intravenous sedation outside of the main operating room for pediatric upper gastrointestinal endoscopy in thailand . this retrospective study was approved by the institutional review board of the faculty of medicine siriraj hospital , mahidol university . all pediatric patients scheduled for ugie procedures consecutively from march 2006 to october 2009 at the wgo endoscopy training center in siriraj hospital were included . due to hospital policy , all children undergoing gie were admitted prior to the procedure . exclusion criteria were the patients who had hemodynamic instabilities and the patients who needed endotracheal intubation . all sedations for ugie were clinically titrated to either moderate or deep sedation as defined according to american academy of pediatrics and american academy of pediatric dentistry .             for all patients who underwent ivs , cardiovascular monitoring included continuous electrocardiogram , heart rate , oxygen saturation measurements and five - minute interval noninvasive blood pressure measurements from blood pressure cuff device . ventilation monitoring included continuous respiratory rate measurements and interval observation of patterns of respiration , chest movement , and signs and symptoms of airway obstruction . end - tidal carbon dioxide ( co2 ) monitoring with capnography or precordial stethoscope was not used during sedation . the following data was obtained : age , gender , weight , asa physical status , indications , presedation problems , successful completion of the procedure , sedation time , type of intervention , and sedative agents . the presedation problems were defined as the underlying diseases such as cardiovascular disease , hematologic disease and liver disease . the effectiveness of intravenous sedation was defined as successful completion of the procedure at the target sedation level as intended . complications were recorded including : hypotension ( defined as a decrease of blood pressure by 20% from baseline and below normal for age ) , hypertension ( defined as an increase of blood pressure by 20% from baseline and above normal for age ) , bradycardia ( defined as a decrease in heart rate by 30% from baseline and below normal for age ) , and hypoxia ( defined as oxygen desaturation with spo2 < 90% ) . serious complication is any adverse event not easily treated or managed with medication and/or maintenance of the patient 's airway resulting in endotracheal intubation including apnea and/or laryngospasm . comparison of adverse events by asa physical status or different medication groups was done by using student t - test . , chicago , il ) was used to analyze the data . a significance level of 5% during the study period , a total of 168 patients ( 94 boys and 74 girls ) , with age ranging from 4 months to 12 years , underwent 176 gie procedures with ivs . of these , 26 ugie procedures were performed with general anesthesia ( ga ) , and 142 ugie procedures were performed with intravenous sedation ( ivs ) and reviewed . all sedation was given by a staff anesthesiologist or the anesthetic personnel directly supervised by a staff anesthesiologist physically present in the endoscopy room . anesthetic personnel included second - year residents in the anesthesiology residency program and anesthetic nurses who are well - trained in general anesthesia , intravenous sedation , airway management including intubation , and cardiopulmonary resuscitation . the equipment used for the procedures included appropriate standard pediatric endoscopes , depending on patient age and size . patient characteristics , duration of sedation , indication of procedure , and the type of interventions are listed in table 1 . hematologic disease , mild to moderate anemia ( 40.1% ) , liver disease , cirrhosis , portal hypertension ( 37.9% ) , and electrolyte imbalances , hypo / hyperkalemia and/or hyponatremia ( 12.4% ) were the most common presedation problems . a total of 142 procedures , anesthesiology residents involved in 74 procedures ( 52.1% ) , and anesthetic nurses involved in 68 procedures ( 47.9% ) . propofol was the most common sedative drugs used in all age and asa physical status groups . mean dose of propofol ( mg / kg ) used in all age groups was significantly different ( p = .032 ) . however , mean dose of propofol ( mg / kg ) used in both asa physical groups was not significantly different ( p = .365 ) . additionally , mean dose of fentanyl ( mcg / kg ) , midazolam ( mg / kg ) and ketamine ( mg / kg ) in all age and asa physical status groups was not significantly different . however , the number of fentanyl used in the 02.99 years - old group ( 60.0% ) was relatively lower than in the other groups ( 86.5% and 87.5% ) . nevertheless , the number of ketamine used in the 02.99 years - old group ( 75.0% ) was significantly higher than in the other groups ( 39.2% and 16.7% ) . according to asa physical status , there were no significant differences in the number of propofol , fentanyl , midazolam and ketamine used . after the patient 's status had improved , the procedure was completed with ga . respiratory complications with hypoxia occurred in seven patients ( 4.9% ) , and upper airway obstruction occurred in six patients ( 4.2% ) . cardiovascular complications arose in 23 patients ( 16.2% ) and mainly consisted of hypotension ( 14 patients ) and bradycardia ( 9 patients ) . if only serious complications are included , the complication rate is none . all complications were easily treated and managed with medication and/or maintenance of the patient 's airway by the staff anesthesiologist or anesthetic personnel under direct supervision of a staff anesthesiologist who was physically present in the room . there was no difference in the incidence of complications when sedated by trainees , anesthetic nurses , or anesthesiologist . the overall complications in children who had asa physical status i - ii as compared to asa physical status iii - iv were not significantly different ( p = .202 ) . in addition , one patient in asa physical status i - ii and one patient in asa physical status iii - iv developed hypoxia and hypotension . two patients in asa physical status i - ii and one patient in asa physical status iii - iv developed upper airway obstruction and bradycardia . the emergence reactions or hallucinations , increased salivation or laryngospasm were not seen in patients receiving ketamine as part of ivs . this retrospective study demonstrates the clinical effectiveness of an anesthesiologist - administered intravenous sedation outside of the main operating room for pediatric upper gastrointestinal endoscopy in a developing country . ivs for pediatric ugie procedure in children 12 years of age and younger is challenge and requires an experienced anesthesiologist as well as appropriate monitoring . anesthetic personnel should remind themselves to use more sensitive equipments to detect potential complication such as end tidal co2 and carefully select more appropriate patients . ugie procedure in children is an important and effective tool for the diagnosis and treatment of upper digestive tract diseases . the indications for upper endoscopy in the pediatric age group are similar to those for adult endoscopy . these procedures are generally performed either with ivs in the endoscopy room , or under ga in the operating room . the decision to use ga is usually based on the patients ' parameters such as age , diagnosis , respiratory compromise and severity of disease . in some centers , ga is used on all infants , children and adolescents [ 3 , 10 , 11 ] . however , in other centers , ivs is used for the procedures . with ivs , several medication combinations have been used successfully [ 9 , 1215 ] .             in a developing country where pediatric ugie performed at increasing rates , the majority of cases are performed under general anesthesia in the operating room ( or ) . at siriraj hospital , there is a dedicated endoscopy unit with dedicated anesthesia service . over the last two years , 2006 to 2008 , we performed most pediatric ugie with ivs [ 57 ] . we followed the guidelines provided by the american academy of pediatrics and american academy of pediatric dentistry and asa standards for sedation providers [ 4 , 16 ] . our previous reviews of ivs practice in pediatric population showed that it can be done safely with various sedative combinations with proper monitoring and anesthesiology service supervision . its use in pediatric population has been shown to be safe , effective and reliable [ 1015 ] . in thailand , propofol is the most common agent used in combination with midazolam and fentanyl in this study . additionally , we did not observe hemodynamic instability , emergence reactions , hallucinations , increased salivation or laryngospasm with the use of ketamine combining regimen . cardiopulmonary complications account for more than half of the major complications during endoscopy , and are often related to hypoxia , especially in children less than 1 year old [ 20 , 21 ] . in our study , the overall adverse event was relatively high ( 25.4% ) . cardiovascular complications accounted for the majority ( 16.2% ) followed by respiratory complications ( 9.2% ) . however , all complications were transient and easily treated with no adverse sequelae . many previous studies involving the use of propofol and other combination sedative drugs have reported slightly higher adverse events [ 2224 ] . in our study , there was significant difference in the mean dose of propofol between the three aged groups .            in a study by barbi and colleagues , major desaturation was noted in 0.7% of all the children , and transient desaturation that resolved sponstaneously occurred in 12% of all the procedures . additionally , the study by yildizda et al . demonstrated that the use of propofol and midazolam / fentanyl in 126 children had 16.6% incidence of respiratory depression as shown by high end - tidal carbon dioxide ( > 50 mmhg ) . the high incidence of respiratory depression reflected the better detection of respiratory depression by the use of end - tidal carbon dioxide . in our study , complication rate is comparable to studies that did not use end - tidal carbon dioxide monitoring [ 22 , 24 ] . asa physical status iii - iv has been shown to be a predictor of increased risk for sedation - related complications . several publications described the use of propofol for sedation by physicians or providers other than anesthesiologists [ 2427 ] . consequently , there was a difference in outcomes once nonanesthesiologists use propofol . when a dedicated pediatric sedation team involving an anesthesiologist was utilized , the reported successful sedation rates were 100% , and adverse events ranged from 1.7 to 5% . a high success rate in our study is due to the procedure is performed by an experienced endoscopist and is sedated by an experienced anesthesiologist . consequently , our center had a dedicated anesthesia service involved with sedation and the use of basic noninvasive monitoring , which includes noninvasive blood pressure monitoring , pulse oximetry , and electrocardiogram . additionally , the safe and successful sedation is also dependent on proper preparation , evaluation , monitoring , and appropriate skills to rescue the patient , and proper recovery . this is a retrospective paper of a cohort of patients undergoing pediatric ugie with ivs . we accept that there are limitations with chart review in regards to proper and complete documentation . we also realized that with this review , the study is reflected in the variety of regimen and sedative drugs used for ivs . therefore , the drug requirement , drug doses , and side effects varied as well . according to the design of study , we defined an alteration of blood pressure by 20% from baseline , and a decrease in heart rate by 30% from baseline as the complication . overall , even with these limitations , we believe that the study findings are applicable to the sedation practice and to remind the physicians for sedation the pediatric patients for ugie procedures .                in summary , this study shows the clinical effectiveness of an anesthesiologist - administered intravenous sedation outside of the main operating room for pediatric upper gastrointestinal endoscopy in a developing country . we also recommend the use of more sensitive equipments to detect potential complication such as end tidal co2 and carefully select more appropriate patients for pediatric ugie .
objectives . to review our sedation practice and to evaluate the clinical effectiveness of an anesthesiologist - administered intravenous sedation outside of the main operating room for pediatric upper gastrointestinal endoscopy ( ugie ) in thailand . subjects and methods . 
 we undertook a retrospective review of the sedation service records of pediatric patients who underwent ugie . 
 all endoscopies were performed by a pediatric gastroenterologist . 
 all sedation was administered by staff anesthesiologist or anesthetic personnel . 
 results . 
 a total of 168 patients ( 94 boys and 74 girls ) , with age from 4 months to 12 years , underwent 176 ugie procedures . 
 of these , 142 ugie procedures were performed with intravenous sedation ( ivs ) . 
 the mean sedation time was 23.2  10.0 minutes . 
 propofol was the most common sedative drugs used . 
 mean dose of propofol , midazolam and fentanyl was 10.0  7.5  mg / kg / hr , 0.2  0.2 
 mg / kg / hr , and 2.5  1.2  mcg / kg / hr , respectively . complications relatively occurred frequently . 
 all sedations were successful . 
 however , two patients became more deeply than intended and required unplanned endotracheal intubation . 
 conclusion . 
 the study shows the clinical effectiveness of an anesthesiologist - administered ivs outside of the main operating room for pediatric ugie in thailand . 
 all complications are relatively high . 
 we recommend the use of more sensitive equipments such as end tidal co2 and carefully select more appropriate patients .