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At least 19 recordsLinked to original sources
PubMed2005

Comparison of the Flexiblade levering laryngoscope with the English Macintosh laryngoscope in patients with a poor laryngoscopic view.

The effectiveness of two laryngoscopes, the English Macintosh and the Flexiblade (a levering laryngoscope), were compared in a clinical setting. An investigation was carried out in 100 patients admitted for surgery under general anaesthesia, to compare intubation with the Flexiblade or the Macintosh laryngoscope. The patients had two anatomical characteristics that may predict difficult intubation - Mallampati score II and III, and a thyromental distance </= 6.5 cm. Patients were randomly allocated to receive intubation with one of the laryngoscopes. The laryngeal view obtained during laryngoscopy, the intubation time, and the need for optimization manoeuvres and assistance required were compared in the two groups. The correlation between intubation time and anatomical characteristics was determined. Only 49 patients had a poor laryngeal view during initial laryngoscopy and required additional facilitating manoeuvres. In these patients, successful intubation time (in seconds) using the Flexiblade was significantly shorter than using the Macintosh laryngoscope (median 14.3 s, IQR 12.0-18.4 s [corrected] vs. median 20.8 s, IQR 14.9-25.5 s (U = 165, [corrected] p , 0.01). Assistance and additional manoeuvres were required significantly less frequently in the Flexiblade group (21%) compared to Macintosh group (67%) (p < 0.01). No correlation was found between intubation time, Mallampati scores, thyromental distance, or body weight. We concluded that in patients with an initial poor laryngoscopic view, the Flexiblade may enable faster and easier tracheal intubation.

Adult↗
PubMed2003

A new universal laryngoscope blade: a preliminary comparison with Macintosh laryngoscope blades.

The Dörges universal laryngoscope blade has several features designed to facilitate tracheal intubation. The number of laryngoscope blades may be reduced from four to two, or even one, which indicate less space requirement and costs. This new universal laryngoscope blade, has a lower profile (height 15 vs. 22 mm) than a Macintosh laryngoscope blade size 3 and 4, which may facilitate manoeuvring of the laryngoscope in the mouth. In random order, 40 non-anaesthesia senior house officers used a Macintosh laryngoscope blade size 3 or 4 in an adult airway management trainer, a Macintosh laryngoscope blade size 2 in a paediatric airway management trainer, and the Dörges universal laryngoscope blade for both airway management trainers to perform orotracheal intubation. The number of intubation attempts and failures was counted. Participants reported the laryngoscopic view according to Cormack and Lehane. The time from touching the laryngoscope to the first adequate lung insufflation was measured, and subjective assessment regarding handling of both blades was recorded. Number of intubation failures, the laryngoscopic view according to Cormack and Lehane, and subjective assessment was comparable between groups. Orotracheal intubation of the adult airway management trainer with the Dörges universal laryngoscope blade took significantly less time compared to the Macintosh laryngoscope blades (14 (7-57) vs. 20 (8-43) s; P<0.001); all other intubating times were comparable. In conclusion, in this model, the Dörges universal laryngoscope blade was comparable to the Macintosh laryngoscope blades size 2-4, and may save time, cost and space.

Adult↗
PubMed2004

The Cardiff paediatric laryngoscope blade: a comparison with the Miller size 1 and Macintosh size 2 laryngoscope blades.

The Cardiff paediatric laryngoscope blade is a single blade that has been designed for use in children from birth to adolescence. This open, randomised, crossover study compared the Cardiff blade with the straight, size 1, Miller laryngoscope blade in 39 infants under 1 years of age and the curved, size 2, Macintosh blade in 39 children aged 1-16 years. The same laryngoscopic view was obtained with the Cardiff and Miller blades in 26 patients; the view was better with the Cardiff blade in seven patients and better with the Miller blade in six (median (IQR [range]) grade of laryngoscopy 1 (1-2 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.405). The Cardiff blade was faster at gaining a view than the Miller blade (mean (SD) time 8.5 (2.9) s vs. 10.2 (3.5) s, respectively; 95% CI for difference -2.8 to -0.4; p = 0.009). The Cardiff and Macintosh blades produced the same view in 32 patients; the view was better with the Cardiff blade in seven patients (median (IQR [range]) grade of laryngoscopy 1 (1-1 [1-3]) vs. 1 (1-2 [1-3]), respectively; p = 0.008). There was no difference in time to gain these views: mean (SD) 8.7 (3.0) s vs. 9.3 (2.7) s, respectively (95% CI for difference -1.58 to 0.40; p = 0.237). The Cardiff paediatric laryngoscope blade compares favourably with these two established laryngoscope blades in children.

Adolescent↗
PubMed1994

Comparison of a rigid laryngoscope with the ultrathin fibreoptic laryngoscope for tracheal intubation in infants.

The flexible ultrathin fibreoptic laryngoscope allows placement of endotracheal tubes as small as 2.5 mm internal diameter. The purpose of this study was to document the safety and efficacy of intubation using an ultrathin fibreoptic laryngoscope. Proved safety and efficacy would justify the routine use of fibreoptic laryngoscopy in normal infants to maintain skills needed for management of the difficult infant airway. In this prospective study, 40 infants < 24 mo of age scheduled for elective surgery were randomly divided into two equal groups. After inhalation induction of anaesthesia, in 20 infants the trachea was intubated using direct rigid laryngoscopy, and in 20 using the ultrathin fibreoptic laryngoscope (size 1.8 mm OD) Olympus LFP. Time to successful intubation was recorded, as well as blood pressure, heart rate, end-tidal CO2 and oxygen saturation. Airway trauma in the operating room, the post-anaesthesia care unit, and on the first postoperative day was recorded. The intubation times using rigid laryngoscopy were less than those using fibreoptic laryngoscopy (13.6 +/- 0.9 sec (mean +/- SEM) vs 22.8 +/- 1.7 sec; P < 0.01). Oxygen saturation and end-tidal CO2 readings were not different between the two groups. After intubation, blood pressure and heart rate increased equally in both groups, returning to normal within one to two minutes. There was no difference in the airway trauma between groups. We conclude that the ultrathin fibreoptic laryngoscope is a safe and effective method for tracheal intubation in infants and may be used routinely in order to maintain fibreoptic airway skills.

Anesthesia, Inhalation↗
PubMed1997

[Cervical spine movement during orotracheal intubation using the McCoy laryngoscope compared with the Macintosh and the Miller laryngoscopes].

The movement of cervical spine during orotracheal intubation was compared using the McCoy, Macintosh or Miller laryngoscope blade. Twenty ASA 1-2 patients requiring tracheal intubation were studied. Following induction of anesthesia and obtaining muscle relaxation, the cross-table lateral X-ray was taken before and during laryngoscopy using three types of laryngoscopes. Degree of cervical spine movement was evaluated by measuring the distance between the spinous processes of C1 and the occiput, and the amount of displacement of C1 and C5 against C3 by tracing on each films. The results indicated that delta C1-occiput was larger and delta C1 + C5 smaller with the McCoy laryngoscope compared with the others. The use of the McCoy laryngoscope results in less cervical spine movement during laryngoscopy and therefore should be of particular benefit in the presence of cervical spine instability as well as in the normal patients.

Adolescent↗
PubMed1977

A laryngoscope for obstetrical use an obstetrical laryngoscope.

Rapid tracheal intubation, using the standard Macintosh laryngoscope, can be hindered in obstetrical patients by the handle of the laryngoscope hitting the patient's engorged breasts and the hand of the assistant applying cricoid pressure. To overcome these difficulties a variation of the laryngoscope is described. The right angle of the blade to the handle is opened by a further 20 degrees.

Female↗
PubMed1993

An analysis of laryngoscope blade shape and design: new criteria for laryngoscope evaluation.

Laryngoscope blade design has tended to be relatively arbitrary and so far scientific analysis has not allowed useful comparisons between blade shapes. A new theoretical method of analysing laryngoscope blades is introduced and uses the depth of insertion profiles of two angular measurements. One represents eyeline displacement and the other the forward space that the blade occupies at the level of the mandible. Photographs of straight and curved blades were studied on Cartesian graphs with the tip T, at the origin and handle fittings parallel to the x-axis of the graph. Then, IT is any line from the origin to the incisor surface and represents a point of contact with the upper incisors for a given depth of blade insertion. Angle EIT (eyeline displacement) is to a tangent from I along the lower lingual surface of the blade. Point M is on the upper lingual surface of the blade, at right angles to IT, 1/3 of the distance from I along IT. Angle MIT (forward space) may be positive or negative depending on whether M is in front of or behind IT. The angles EIT, MIT and their additive combination are used in blade analysis. Negative MIT compensates for eyeline displacement as Macintosh size 3 and 4 blades have better combination scores than Miller size 3. All three are superior to the straight Soper size 3 blade. The Macintosh size 1 and 2 blades are quite different from the larger Macintosh blades. This theoretical basis for blade analysis is consistent with commonly expressed clinical opinions and may influence blade design in the future.

Equipment Design↗
PubMed1987

A new laryngoscope. A modified laryngoscope to facilitate intubation in cases of restricted access.

This is a report of a modification to one design of laryngoscope to increase the angle between blade and handle, to facilitate intubation in cases of difficult access, such as in obstetric practice or in patients in whom neck flexion is limited, for example by skull traction. The modification offers the unique advantage of two useful blade angles in one instrument. The first type described would be suitable for use in small units where it is thought that a laryngoscope solely for use in rare cases of difficult access would not be justified. It would also be suitable for inclusion in resuscitation kits for use both within and outside hospital. The second type would be more suitable for the maternity or spinal injuries unit, or the difficult intubation box of a general operating theatre suite.

Equipment Design↗
PubMed2003

Randomized evaluation of the performance of single-use laryngoscopes in simulated easy and difficult intubation.

BACKGROUND: Single-use laryngoscopes are becoming used more widely. METHODS: We compared six types of single-use laryngoscope with the standard Macintosh laryngoscope using the Laerdal SimMan patient simulator. Twenty anaesthetists attempted to intubate the simulator with standardized airway settings allowing a full view of the vocal cords ('easy intubation'). The airway settings were then changed so that only the posterior part of the glottis was visible ('difficult intubation') and the anaesthetists were asked to intubate the simulator again. RESULTS: The time to intubate with the standard laryngoscope was less in both easy (P<0.05) and difficult (P<0.01) intubations. The performance of five laryngoscopes during easy intubation (P<0.01) and four during difficult intubation (P<0.001) was significantly worse than that of the Macintosh. There was a significant difference in Cormack and Lehane grading between the laryngoscopes tested in both easy (P<0.05) and difficult (P<0.05) intubation. The percentage of glottic opening visible (POGO score) also differed between laryngoscopes in both the easy (P<0.01) and difficult (P<0.001) groups. The highest POGO scores were obtained with the Macintosh laryngoscope. During the difficult intubation simulation, the reusable Macintosh laryngoscope needed less use of a bougie and had fewer failed intubations than the single-use laryngoscopes, but these differences did not reach statistical significance. CONCLUSIONS: Of the laryngoscopes tested, the standard reusable Macintosh laryngoscope performed best. The Europa was the best single-use laryngoscope. Some single-use laryngoscopes tested were significantly inferior to the Macintosh. This raises concern over their use in clinical practice, particularly if intubation is difficult.

Disposable Equipment↗
PubMed1997

Comparison of the Bullard and Macintosh laryngoscopes for endotracheal intubation of patients with a potential cervical spine injury.

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 precautions 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 laryngoscopes 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 degrees +/- 2.8 degrees). Extension was reduced when using the Macintosh laryngoscope with ILS (12.9 +/- 2.1 degrees) and the Bullard laryngoscope without stabilization (12.6 +/- 1.8 degrees; 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 degrees) 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 precautions 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.

Adult↗
PubMed2000

The McCoy laryngoscope, external laryngeal pressure, and their combined use.

The efficacy of the McCoy laryngoscope, external laryngeal pressure, and their combination to improve the laryngoscopic view was evaluated in 219 patients and compared with the Macintosh laryngoscope. An experienced laryngoscopist performed laryngoscopy twice using the Macintosh laryngoscope and the McCoy laryngoscope in a random sequence, and external laryngeal pressure was applied in each laryngoscopy with the laryngoscopist's right hand. The laryngoscopic view obtained was graded on our modified Cormack's method. Without external laryngeal pressure, the McCoy laryngoscope provided a better laryngoscopic view than that obtained by the Macintosh laryngoscope (P < 0.001, signed rank test), but the view was worse than that with the Macintosh laryngoscope under external laryngeal pressure (P < 0.001). The McCoy laryngoscope combined with external laryngeal pressure provided a better view than the Macintosh laryngoscope with external laryngeal pressure (P < 0.001).

Equipment Design↗
PubMed2006

Evaluation of the new Viewmax laryngoscope in a simulated difficult airway.

BACKGROUND: In this study, we evaluated the learning curve and performance of the Viewmax laryngoscope during simulated difficult laryngoscopy in an intubation manikin (Laerdal Airway Management Trainer). METHODS: To determine the learning curve, 25 anaesthesiologists without previous experience with the Viewmax laryngoscope performed 10 successive intubations in an intubation manikin with a normal airway. Time to intubation and failed intubation attempts were recorded. Another manikin was modified to enable comparison of the Viewmax laryngoscope with Macintosh and McCoy laryngoscopes. The time to intubation, number of failed intubation attempts, modified Cormack and Lehane (MCL) laryngeal view grading, percentage of glottic opening (POGO score), use of gum elastic bougie and subjective rating of degree of difficulty were recorded. RESULTS: The learning curve for the Viewmax laryngoscope showed a progressive decrease in time to successful intubation and reached a plateau at the sixth attempt. In simulated difficult laryngoscopy, the Viewmax laryngoscope demonstrated significantly better laryngeal view than the Macintosh and McCoy laryngoscopes in terms of MCL grading (Macintosh, P = 0.01; McCoy, P < 0.01) and POGO score (Macintosh, P < 0.01; McCoy, P < 0.01). The time required for intubation in simulated difficult laryngoscopy for the Viewmax laryngoscope was significantly longer than that for the Macintosh (P = 0.02) and McCoy (P < 0.01) laryngoscopes. There was no significant difference in the degree of difficulty, number of failed intubations and use of gum elastic bougie. CONCLUSION: When compared with the Macintosh and McCoy laryngoscopes in a manikin, the Viewmax laryngoscope appears to improve the view of the larynx but requires a longer time for tracheal intubation.

Clinical Competence↗
PubMed2001

Evaluation of the disposable Vital View laryngoscope apparatus.

The Vital View laryngoscope (Vital Signs, NJ, USA) consists of a plastic disposable blade containing a fibrelight and a non-disposable handle; there is therefore no need to sterilise the blade and no concern about disintegration of the fibrelight. In a random cross-over design, we compared the Vital View laryngoscope with a conventional metal fibrelight laryngoscope (Welch Allyn, NY, USA) in 100 patients. The Vital View laryngoscope produced a brighter field than the metal laryngoscope (p < 0.001), whereas there was no significant difference in the view of the glottis or the success rate of tracheal intubation. In no patient did any problem occur, such as damage to the laryngoscope blade or loss of light during laryngoscopy. In another 10 patients, prevention of light emission from the side of the laryngoscope blade reduced the brightness (p < 0. 01). This indicated that the brightness of the Vital View laryngoscope is produced by light emission not only from the tip of the blade but also from the side of the blade. Therefore, the disposable Vital View laryngoscope can be used as effectively as a conventional non-disposable laryngoscope.

Adolescent↗
PubMed1995

Cervical spine movement during laryngoscopy with the Bullard, Macintosh, and Miller laryngoscopes.

BACKGROUND: Direct laryngoscopy requires movement of the head, neck, and cervical spine. Spine movement may be limited for anatomic reasons or because of cervical spine injury. The Bullard laryngoscope, a rigid fiberoptic laryngoscope, may cause less neck flexion and head extension than conventional laryngoscopes. The purpose of this study was to compare head extension (measured externally), cervical spine extension (measured radiographically), and laryngeal view obtained with the Bullard, Macintosh, and Miller laryngoscopes. METHODS: Anesthesia was induced in 35 ASA 1-3 elective surgery patients. Patients lay on a rigid board with head in neutral position. Laryngoscopy was performed three times, changing between the Bullard, Macintosh, and Miller laryngoscopes. Head extension was measured with an angle finder attached to goggles worn by the patient. The best laryngeal view with each laryngoscope was assessed by the laryngoscopist. In eight patients, lateral cervical spine radiographs were taken before and during laryngoscopy with the Bullard and Macintosh blades. RESULTS: Median values for external head extension were 11 degrees, 10 degrees, and 2 degrees with the Macintosh, Miller, and Bullard laryngoscopy (P < 0.01), respectively. Significant reductions in radiographic cervical spine extension were found for the Bullard compared to the Macintosh blade at the atlantooccipital joint, atlantoaxial joint, and C3-C4. Median atlantooccipital extension angles were 6 degrees and 12 degrees for the Bullard and Macintosh laryngoscopes, respectively. The larynx could be exposed in all patients with the Bullard but only in 90% with conventional laryngoscope (P < 0.01). CONCLUSIONS: The Bullard laryngoscope caused less head extension and cervical spine extension than conventional laryngoscopes and resulted in a better view. It may be useful in care of patients in whom cervical spine movement is limited or undesirable.

Adult↗