***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: Introduction In the emergency department setting , it is essential to rapidly and accurately confirm correct endotracheal tube ( ETT ) placement .  Ultrasound is an increasingly studied modality for identifying ETT location . However , there has been significant variation in techniques between studies , with some using the dynamic technique , while others use a static approach . This study compared the static and dynamic techniques to determine which was more accurate for ETT identification . Methods We performed this study in a cadaver lab using three different cadavers to represent variations in neck circumference . Cadavers were r and omized to either tracheal or esophageal intubation in equal proportions . Blinded sonographers then assessed the location of the ETT using either static or dynamic sonography . We assessed accuracy of sonographer identification of ETT location , time to identification , and operator confidence . Results A total of 120 intubations were performed : 62 tracheal intubations and 58 esophageal intubations . The static technique was 93.6 % ( 95 % confidence interval [ CI ] [ 84.3 % to 98.2 % ] ) sensitive and 98.3 % specific ( 95 % CI [ 90.8 % to 99.9 % ] ) . The dynamic technique was 92.1 % ( 95 % CI [ 82.4 % to 97.4 % ] ) sensitive and 91.2 % specific ( 95 % CI [ 80.7 % to 97.1 % ] ) . The mean time to identification was 6.72 seconds ( 95 % CI [ 5.53 to 7.9 ] seconds ) in the static technique and 6.4 seconds ( 95 % CI [ 5.65 to 7.16 ] seconds ) in the dynamic technique . Operator confidence was 4.9/5.0 ( 95 % CI [ 4.83 to 4.97 ] ) in the static technique and 4.86/5.0 ( 95 % CI [ 4.78 to 4.94 ] ) in the dynamic technique . There was no statistically significant difference between groups for any of the outcomes . Conclusion This study demonstrated that both the static and dynamic sonography approaches were rapid and accurate for confirming ETT location with no statistically significant difference between modalities . Further studies are recommended to compare these techniques in ED patients and with more novice sonographers Introduction : Confirmation of proper endotracheal tube placement is one of the most important and lifesaving issues of tracheal intubation . The present study was aim ed to evaluate the accuracy of  tracheal ultrasonography  by emergency residents in this regard . Method : This was a prospect i ve , cross sectional study for evaluating the diagnostic accuracy of ultrasonography in endotracheal tube placement confirmation compared to a combination of 4 clinical confirmation methods of chest and epigastric auscultation , direct laryngoscopy , aspiration of the tube , and pulse oximetry ( as reference test ) . Results : 150 patients with the mean age of 58.52 ± 1.73 years were included ( 56.6 % male ) . Sensitivity , specificity , positive predictive value , negative predictive value , and positive and negative likelihood ratio of tracheal ultrasonography  in endotracheal tube confirmation were 96 ( 95 % CI : 92 - 99 ) , 88 ( 95 % CI : 62 - 97 ) , 98 ( 95 % CI : 94 - 99 ) , 78 ( 95 % CI : 53 - 93 ) , 64 ( 95 % CI : 16 - 255 ) , and 0.2 ( 95 % CI : 0.1 - 0.6 ) , respectively . Conclusion : The present study showed that tracheal ultrasonography by trained emergency medicine residents had excellent sensitivity ( > 90 % ) and good specificity ( 80 - 90 ) for confirming endotracheal tube placement . Therefore , it seems that ultrasonography is a proper screening tool in determining endotracheal tube placement Background In emergency setting s , verification of endotracheal tube ( ETT ) location is important for critically ill patients . Ignorance of oesophageal intubation can be disastrous . Many methods are used for verification of the endotracheal tube location ; none are ideal . Quantitative waveform capnography is considered the st and ard of care for this purpose but is not always available and is expensive . Therefore , this feasibility study is conducted to compare a cheaper alternative , bedside upper airway ultrasonography to waveform capnography , for verification of endotracheal tube location after intubation . Methods This was a prospect i ve , single-centre , observational study , conducted at the HRPB , Ipoh . It included patients who were intubated in the emergency department from 28 March 2012 to 17 August 2012 . A waiver of consent had been obtained from the Medical Research Ethics Committee . Bedside upper airway ultrasonography was performed after intubation and compared to waveform capnography .  Specificity , sensitivity , positive and negative predictive value and likelihood ratio are calculated . Results A sample of 107 patients were analysed , and 6 ( 5.6 % ) had oesophageal intubations . The overall accuracy of bedside upper airway ultrasonography was 98.1 % ( 95 % confidence interval ( CI ) 93.0 % to 100.0 % ) . The kappa value ( Κ ) was 0.85 , indicating a very good agreement between the bedside upper airway ultrasonography and waveform capnography . Thus , bedside upper airway ultrasonography is in concordance with waveform capnography . The sensitivity , specificity , positive predictive value and negative predictive value of bedside upper airway ultrasonography were 98.0 % ( 95 % CI 93.0 % to 99.8 % ) , 100 % ( 95 % CI 54.1 % to 100.0 % ) , 100 % ( 95 % CI 96.3 % to 100.0 % ) and 75.0 % ( 95 % CI 34.9 % to 96.8 % ) . The likelihood ratio of a positive test is infinite and the likelihood ratio of a negative test is 0.0198 ( 95 % CI 0.005 to 0.0781 ) . The mean confirmation time by ultrasound is 16.4 s. No adverse effects were recorded . Conclusions Our study shows that ultrasonography can replace waveform capnography in confirming ETT placement in centres without capnography . This can reduce incidence of unrecognised oesophageal intubation and prevent morbidity and mortality . Trial registration National Medical Research Register NMRR11100810230 Introduction Recent research has investigated the use of ultrasound ( US ) for confirming endotracheal tube ( ETT ) placement with varying techniques , accuracies , and challenges . Our objective was to evaluate the accuracy of a novel , simplified , four-step ( 4S ) technique . Methods We conducted a blinded , r and omized trial of the 4S technique utilizing an adult human cadaver model . ETT placement was r and omized to tracheal or esophageal location . Three US experts and 45 emergency medicine residents ( EMR ) performed a total of 150 scans . The primary outcome was the overall sensitivity and specificity of both experts and EMRs to detect location of ETT placement . Secondary outcomes included a priori subgroup comparison of experts and EMRs for thin and obese cadavers , time to detection , and level of operator confidence . Results Experts had a sensitivity of 100 % ( 95 % CI = 72 % to 100 % ) and specificity of 100 % ( 95 % CI = 77 % to 100 % ) on thin , and a sensitivity of 93 % ( 95 % CI = 66 % to 100 % ) and specificity of 100 % ( 95 % CI = 75 % to 100 % ) on obese cadavers . EMRs had a sensitivity of 91 % ( 95 % CI = 69 % to 98 % ) and of specificity 96 % ( 95 % CI = 76 % to 100 % ) on thin , and a sensitivity of 100 % ( 95 % CI = 82 % to 100 % ) specificity of 48 % ( 95 % CI = 27 % to 69 % ) on obese cadavers . The overall mean time to detection was 17 seconds ( 95 % CI = 13 seconds to 20 seconds , range : 2 to 63 seconds ) for US experts and 29 seconds ( 95 % CI = 25 seconds to 33 seconds ; range : 6 to 120 seconds ) for EMRs . There was a statistically significant decrease in the specificity of this technique on obese cadavers when comparing the EMRs and experts , as well as an increased overall time to detection among the EMRs . Conclusion The simplified 4S technique was accurate and rapid for US experts . Among novices , the 4S technique was accurate in thin , but appears less accurate in obese cadavers . Further studies will determine optimal teaching time and accuracy in emergency department patients OBJECTIVES This study aim ed to assess the diagnostic accuracy and timeliness of using tracheal ultrasound to examine endotracheal tube placement during emergency intubation . METHODS This was a prospect i ve , observational study , conducted at the emergency department of a national university teaching hospital . Patients received emergency intubation because of impending respiratory failure , cardiac arrest , or severe trauma . The tracheal rapid ultrasound exam ( T.R.U.E. ) was performed during emergency intubation with the transducer placed transversely at the trachea over the suprasternal notch . Quantitative waveform capnography  was used as the criterion st and ard for confirmation of tracheal intubation . The main outcome was the concordance between the T.R.U.E. and the capnography . RESULTS A total of 112 patients were included in the analysis , and 17 ( 15.2 % ) had esophageal intubations . The overall accuracy of the T.R.U.E. was 98.2 % ( 95 % confidence interval [ CI ] : 93.7 - 99.5 % ) . The kappa ( κ ) value was 0.93 ( 95 % CI : 0.84 - 1.00 ) , indicating a high degree of agreement between the T.R.U.E. and capnography . The sensitivity , specificity , positive predictive value , and negative predictive value of the T.R.U.E. were 98.9 % ( 95 % CI : 94.3 - 99.8 % ) , 94.1 % ( 95 % CI : 73.0 - 99.0 % ) , 98.9 % ( 95 % CI : 94.3 - 99.8 % ) and 94.1 % ( 95 % CI : 73.0 - 99.0 % ) . The median operating time of the T.R.U.E. was 9.0s ( interquartile range [ IQR ] : 6.0 , 14.0 ) . CONCLUSIONS The application of the T.R.U.E. to examine endotracheal tube placement during emergency intubation is feasible , and can be rapidly performed Background Unrecognized esophageal intubations are associated with significant patient morbidity and mortality . No single confirmatory device has been shown to be 100 % accurate at ruling out esophageal intubations in the emergency department . Recent studies have demonstrated that point-of-care ultrasound ( POCUS ) may be a useful adjunct for confirming endotracheal tube placement ; however , the amount of practice required to become proficient at this technique is unclear . The purpose of this study is to determine the amount of practice required by emergency physicians to become proficient at interpreting ultrasound video clips of esophageal and endotracheal intubations . Methods Emergency physicians and emergency medicine residents completed a baseline interpretation test followed by a 10 min online tutorial . They then interpreted POCUS clips of esophageal and endotracheal intubations in a r and omly selected order . If an incorrect response was provided , the participant completed another practice session with feedback . This process continued until they correctly interpreted ten consecutive ultrasound clips . Descriptive statistics were used to summarize the data . Results Of the 87 eligible physicians , 66 ( 75.9 % ) completed the study . The mean score on the baseline test was 42.9 % ( SD 32.7 % ) . After the tutorial , 90.9 % ( 60/66 ) of the participants achieved proficiency after one practice attempt and 100 % achieved proficiency after two practice attempts . Six intubation ultrasound clips were misinterpreted , for a total error rate of 0.9 % ( 6/684 ) . Overall , the participants had a sensitivity of 98.3 % ( 95 % CI 96.3–99.4 % ) and specificity of 100 % ( 95 % CI 98.9–100 % ) for detecting correct tube location . Scans were interpreted within an average of 4 s ( SD 2.9 s ) of the intubation . Conclusions After a brief online tutorial and only two practice attempts , emergency physicians were able to quickly and accurately interpret ultrasound intubation clips of esophageal and endotracheal intubations STUDY OBJECTIVE Visualization of the vocal cords and end-tidal capnography are the usual st and ards in confirming endotracheal tube placement . Vocal cord visualization is , however , not always possible , and capnography is not 100 % reliable and requires ventilation of the lungs to confirm placement . The goal of this study is to determine the accuracy of ultrason 
    Output:
    
Conclusion : Transtracheal sonography is rapid to perform , with an acceptable degree of sensitivity and specificity for the confirmation of endotracheal intubation .