***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: Background The purpose of our study was to organize the literature regarding the efficacy of modern videolaryngoscopes in oral endotracheal intubation , then perform a quality assessment according to recommended external criteria and make recommendations for use . Methods Inclusion criteria included devices with recent studies of human subjects . A total of 980 articles were returned in the initial search and 65 additional items were identified using cited references . After exclusion of articles failing to meet study criteria , 77 articles remained . Data were extracted according to the rate of successful intubation and improvement of glottic view compared with direct laryngoscopy . Studies were classified according to whether they primarily examined subjects with normal airways , possessing risk factors for difficult direct laryngoscopy , or following difficult or failed direct laryngoscopy . Results The evidence of efficacy for videolaryngoscopy in the difficult airway is limited . What evidence exists is both r and omized prospect i ve and observational in nature , requiring a scheme that evaluates both forms and allows recommendations to be made . Conclusions In patients at higher risk of difficult laryngoscopy we recommend the use of the Airtraq , CTrach , GlideScope , Pentax AWS and V-MAC to achieve successful intubation . In difficult direct laryngoscopy ( C&L > /= 3 ) we cautiously recommend the use of the Airtraq , Bonfils , Bullard , CTrach , GlideScope , and Pentax AWS , by an operator with reasonable prior experience , to achieve successful intubation when used in accordance with the ASA practice guidelines for management of the difficult airway . There is additional evidence to support the use of the Airtraq , Bonfils , CTrach , GlideScope , McGrath , and Pentax AWS following failed intubation via direct laryngoscopy to achieve successful intubation . Future investigation would benefit from precise qualification of the subjects under study , and an improvement in overall methodology to include r and omization and blinding Background For patients suspicious of cervical spine injury , a Philadelphia cervical collar is usually applied . Application of Philadelphia cervical collar may cause difficult airway . The aim of this study was to evaluate the laryngeal view and the success rate at first intubation attempt of the Airtraq and conventional laryngoscopy in patients with simulated cervical spine injury after application of a Philadelphia cervical collar .  Methods Anesthesia was induced with propofol , remifentanil , and rocuronium . After a Philadelphia cervical collar applied , patients were r and omly assigned to tracheal intubation with an Airtraq ( Group A , n = 25 ) or with conventional laryngoscopy ( Group L , n = 25 ) . Measurements included intubation time , success rate of first intubation attempt , number of intubation attempts , and percentage of glottic opening ( POGO ) score . Mean blood pressure and heart rate were also recorded at baseline , just before and after intubation . Results The success rate of the first attempt in Group A ( 96 % ) was significantly greater than with the Group L ( 40 % ) . POGO score was significantly greater in Group A ( 84 ± 20 % ) than in Group L ( 6 ± 11 % ) . The duration of successful intubation at first tracheal intubation attempt and hemodynamic changes were not significantly different between the two groups . Conclusions The Airtraq offers a better laryngeal view and higher success rate at first intubation attempt in patients who are applied with a Philadelphia cervical collar due to suspicion of cervical spine injury The Airtraq ® laryngoscope is a novel single use tracheal intubation device . We compared the Airtraq ® with the Macintosh laryngoscope in patients deemed at low risk for difficult intubation in a r and omised , controlled clinical trial . Sixty consenting patients presenting for surgery requiring tracheal intubation were r and omly allocated to undergo intubation using a Macintosh ( n = 30 ) or Airtraq ® ( n = 30 ) laryngoscope . All patients were intubated by one of four anaesthetists experienced in the use of both laryngoscopes . No significant differences in demographic or airway variables were observed between the groups . All but one patient , in the Macintosh group , was successfully intubated on the first attempt . There was no difference between groups in the duration of intubation attempts . In comparison to the Macintosh laryngoscope , the Airtraq ® result ed in modest improvements in the intubation difficulty score , and in ease of use . Tracheal intubation with the Airtraq ® result ed in less alterations in heart rate . These findings demonstrate the utility of the Airtraq ® laryngoscope for tracheal intubation in low risk patients Background : The Glide Scope videolaryngoscope provides a suitable view for intubation , with less force required . Objectives : The present study was conducted , to compare postoperative sore throat and hoarseness after laryngoscopy and intubation , by Macintosh blade or Glide Scope video laryngoscope  in normal airway patients . Patients and Methods : Three hundred patients were r and omly allocated into two groups of 150 : Macintosh blade laryngoscope or Glide Scope video laryngoscope . The patients were evaluated for 48 hours for sore throat and hoarseness by an interview . Results : The incidence and severity of sore throat in the Glide Scope group , at 6 , 24 and 48 hours after the operation , were significantly lower than in the Macintosh laryngoscope group . In addition , the incidence of hoarseness in the Glide Scope group , at 6 and 24 hours after the operation , were significantly lower than in the Macintosh laryngoscope group . The incidence and severity of sore throat  in men , at 6 and 24 hours after the operation , were significantly lower than in the women . Conclusions : The incidence and severity of sore throat and hoarseness after tracheal intubation by Glide Scope were lower than in the Macintosh laryngoscope . The incidence and severity of sore throat were increased by intubation and longer operation times Endotracheal intubation involving conventional laryngoscopy elicits a haemodynamic response associated with increased heart and blood pressure . The study was aim ed to see if video laryngoscopy and endotracheal intubation has any advantages over conventional laryngoscopy and endotracheal intubation in patients with coronary artery disease . Thirty patients suffering from coronary artery disease scheduled for elective coronary artery bypass grafting ( CABG ) were studied . The patients were r and omly allocated to undergo either conventional laryngoscopy ( group A ) or video laryngoscopy ( group B ) . The time taken to perform endotracheal intubation and haemodynamic changes associated with intubation were noted in both the groups at different time points . The duration of laryngoscopy and intubation was significantly longer in group B ( video laryngoscopy ) when compared to group A patients . However , haemodynamic changes were no different between the groups . There were no events of myocardial ischaemia as monitored by surface electrocardiography during the study period in either of the groups . In conclusion , video laryngoscopy did not provide any benefit in terms of haemodynamic response to laryngoscopy and intubation in patients undergoing primary CABG with a Mallampatti grade of < 2 Background : In the emergency trauma situation , in‐line stabilization ( ILS ) of the cervical spine is used to reduce head and neck extension during laryngoscopy . The Bullard laryngoscope may result in less cervical spine movement than the Macintosh laryngoscope . The aim of this study was to compare cervical spine extension ( measured radiographically ) and time to intubation with the Bullard and Macintosh laryngoscopes during a simulated emergency with cervical spine pre caution s taken . Methods : Twenty‐nine patients requiring general anesthesia and endotracheal intubation were studied . Patients were placed on a rigid board and anesthesia was induced . Laryngoscopy was performed on four occasions : with the Bullard and Macintosh laryngoscope both with and without manual ILS . Cricoid pressure was applied with ILS . To determine cervical spine extension , radiographs were exposed before and during laryngoscopy . Times to intubation and grade view of the larynx were also compared . Results : Cervical spine extension ( occiput‐C5 ) was greatest with the Macintosh laryngoscope ( 25.9 [ degree sign ] + /‐ 2.8 [ degree sign ] ) . Extension was reduced when using the Macintosh laryngoscope with ILS ( 12.9 + /‐ 2.1 [ degree sign ] ) and the Bullard laryngoscope without stabilization ( 12.6 + /‐ 1.8 [ degree sign ] ; P < 0.05 ) . Times to intubation were similar for the Macintosh laryngoscope with ILS ( 20.3 + /‐ 12.8 s ) and for the Bullard without ILS ( 25.6 + /‐ 10.4 s ) . Manual ILS with the Bullard laryngoscope results in further reduction in cervical spine extension ( 5.6 + /‐ 1.5 [ degree sign ] ) but prolongs time to intubation ( 40.3 + /‐ 19.5 s ; P < 0.05 ) . Conclusions : Cervical spine extension and time to intubation are similar for the Macintosh laryngoscope with ILS and the Bullard laryngoscope without ILS . However , time to intubation is significantly prolonged when the Bullard laryngoscope is used in a simulated emergency with cervical spine pre caution s taken . This suggests that the Bullard laryngoscope may be a useful adjunct to intubation of patients with potential cervical spine injury when time to intubation is not critical BACKGROUND The purpose of this study was to evaluate the effectiveness of the Pentax AWS , Glidescope , and the Truview EVO2 , in comparison with the Macintosh laryngoscope , when performing tracheal intubation in patients with neck immobilization using manual in-line axial cervical spine stabilization . METHODS One hundred and twenty consenting patients presenting for surgery requiring tracheal intubation were r and omly assigned to undergo intubation using a Macintosh ( n=30 ) , Glidescope ( n=30 ) , Truview EVO2 ( n=30 ) , or AWS ( n=30 ) laryngoscope .  All patients were intubated by one of the three anaesthetists experienced in the use of each laryngoscope . RESULTS The Glidescope , AWS , and Truview EVO2 each reduced the intubation difficulty score ( IDS ) , improved the Cormack and Lehane glottic view , and reduced the need for optimization manoeuvres , compared with the Macintosh . The mean IDS was significantly lower with the Glidescope and AWS compared with the Truview EVO2 device , and the IDS was lowest with the AWS . The duration of tracheal intubation attempts was significantly shorter with the Macintosh compared with the other devices . There were no differences in success rates between the devices tested . The AWS produced the least haemodynamic stimulation . CONCLUSIONS The Glidescope and AWS laryngoscopes required more time but reduced intubation difficulty and improved glottic view over the Macintosh laryngoscope more than the Truview EVO2 laryngoscope when used in patients undergoing cervical spine immobilization We performed a r and omised trial comparing the CEL‐100 videolaryngoscopeTM with the Macintosh laryngoscope blade in 170 patients undergoing double‐lumen tube placement for thoracic surgery . Compared with the Macintosh laryngoscope blade , use of the CEL‐100 result ed in significantly more patients with a Cormack and Lehane Grade ‐1 laryngeal view ( 90.4 % vs 61.0 % , p < 0.001 ) , a higher rate of successful intubation on the first attempt ( 92.8 % vs 79.3 % , p = 0.012 ) , a lower median ( IQR [ range ] ) intubation difficulty score ( 0 ( 0–0 [ 0–60 ] ) vs 15 ( 0–30 [ 0–80 ] ) , p < 0.001 ) , a higher incidence of correct positioning of the tube ( 90.3 % vs 79.2 % , p = 0.041 ) and significantly fewer patients requiring external laryngeal pressure ( 19.3 % vs 32.9 % , p = 0.046 ) . Median ( IQR [ range ] ) time to successful intubation was 45 ( 38–55 [ 22–132 ] ) s with the CEL‐100 compared with 51 ( 40–61 [ 30–160 ] s using the Macintosh laryngoscope blade . We conclude that the CEL‐100 videolaryngoscope is superior to the Macintosh laryngoscope blade for double‐lumen tube insertion Background : The Truview EVO2(C ) laryngoscope ( TL ) is a recently introduced optical device design ed to provide an unmagnified anterior image of the glottic opening and allow indirect laryngoscopy . Aim : This study is design ed to determine whether the TL is a better alternative to the Macintosh laryngoscope ( ML ) for routine endotracheal intubations in patients with usual airway characteristics . Methods : We compared the Truview EVO2(C ) and MLs in 140 elective surgical patients requiring general anaesthesia and intubation in a prospect i ve crossover fashion . The two blades were compared in terms of Cormack and Lehane grade s , time required for intubation , anaesthetists ’ assessment of ease of intubation , intubation difficulty score , attempts at intubation , success rate , soft tissue damage and arterial oxygen saturation during laryngoscopy . The 
    Output:
    
Videolaryngoscopes may reduce the number of failed intubations , particularly among patients presenting with a difficult airway .
They improve the glottic view and may reduce laryngeal/airway trauma .
Currently , no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications , and no evidence indicates that use of a VLS affects time required for intubation