| ||||||||||||||
|
|
|||||||||||||


*Labor Welfare Corporation, Spinal Injuries Center,
University of Occupational and Environmental Health, School of Medicine, Fukuoka, Japan
Address correspondence and reprint requests to Yoshitaka Inoue, MD, PhD, Department of Anesthesia, Labor Welfare Corporation, Spinal Injuries Center, 550-4 Igisu, Iizuka, Fukuoka, 820-8508 Japan. Address e-mail to y0inouwe{at}pastel.ocn.ne.jp
| Abstract |
|---|
|
|
|---|
IMPLICATIONS: The TrachlightTM may be more advantageous for orotracheal intubation in patients with cervical spine disorders than the FastrachTM with respect to reliability, rapidity and safety.
| Introduction |
|---|
|
|
|---|
Fiberoptic laryngoscopy in awake patients may facilitate tracheal intubation with little or no cervical motion (13,14); this technique, however, has several inherent limitations including patient cooperation, specialized expertise, complication with excessive secretions, blood, or vomitus, and the high cost of equipment maintenance.
A newly designed lightwand device (TrachlightTM, Laerdal Medical, Armonk, NY) or an intubating laryngeal mask (FastrachTM, Intavent Ltd, Berkshire, UK) may avoid hyperextension of the occipito-atlanto-axial complex. These new devices have been suggested as alternatives for safer tracheal intubation than conventional direct laryngoscopy (1518). However, most studies of these devices have been performed in patients with normal airways, and there are few objective data that guide appropriate selection of either of them.
We therefore conducted a prospective randomized study to evaluate and compare the efficacy of these devices in patients with known or potential spine disorders.
| Methods |
|---|
|
|
|---|
Before performing the study, a single investigator (YI) had used FastrachTM in 33 patients and TrachlightTM in 37 patients with the neck maintained in a neutral position. We confirmed that there was no technical difficulty in the use of the devices. The investigator had used a standard laryngeal mask airway for more than 10 yr in routine practice, whereas he had never used FastrachTM or TrachlightTM before the preliminary trials.
The same investigator assessed the risk of induction of general anesthesia in all patients. If difficulty in mask ventilation with a neutral position of the head and neck was predicted after patient assessment, the patient was withdrawn from this study. In excluded cases, awake nasal fiberoptic intubation was applied. The patients included in this study were randomly assigned into either a TrachlightTM group or a FastrachTM group. In both groups, general anesthesia was induced with 12 mg/kg propofol and 100 µg fentanyl IV and muscle relaxation was produced with 0.1 mg/kg vecuronium IV. All procedures were performed with the patients head and neck placed in a neutral position using an appropriately sized pillow. The neck collar was removed because it would prevent mask ventilation and light identification on the neck; whereas in the patient with a halo-vest, we attempted the trials without removing the vest. We used a reinforced tracheal tube (Fuji System, Tokyo, Japan) in the TrachlightTM group and a BlueLineTM tube (Portex, Hythe Kent, UK) in the FastrachTM group. In both groups, an appropriate size of the tracheal tube was selected (inner diameter, 7.58.0 mm in males and 7.07.5 mm in females).
In the TrachlightTM group, two attempts limited to 30 s each were allowed for tracheal intubation. If it was impossible to intubate the trachea within these two attempts, it was regarded as a failure and the study was terminated. The trachea was then intubated with the investigators preference.
In the FastrachTM group, a size #5 FastrachTM was used unless it was judged to be too large; in such a case, a size #4 was chosen. Two attempts for insertion of the laryngeal mask portion of the FastrachTM system were allowed. After the insertion, the cuff was inflated with 2540 mL volume of air. Balloon pressure was manually verified. A respiratory system was connected and then manual ventilation was attempted. When tidal volumes with more than 10 mL/kg and an appropriate movement of the chest wall were obtained during manual ventilation with 15 cm H2O airway pressure, it was judged a clinically acceptable ventilation. The respiratory system was disconnected and then insertion of an endotracheal tube through the FastrachTM was attempted. Only one attempt was allowed for "blind" tracheal intubation, because we felt that manipulation of the FastrachTM may influence alignment of the cervical spine. If the blind intubation failed, fiberoptic bronchoscope-guided tracheal intubation through the FastrachTM was attempted. If it was impossible to insert FastrachTM, or impossible to intubate the trachea with both attempts, it was regarded as a failure and the study was terminated. The trachea was then intubated with the investigators preference.
The number of attempts and the time for tracheal intubation, defined as the duration between the time when the attempt for insertion of the test device into the oropharynx was started and the time when manual ventilation through the tracheal tube was restarted, were recorded. Any complications during the attempts were recorded. Postoperative assessment by patient interview and review of the chart for neurological examination were performed on postoperative day 7. Demographic data and intubation time were reported as mean ± SD. All continuous data of the TrachlightTM group and the FastrachTM group were analyzed using an unpaired Students t-test. Nominal data were analyzed using the
2 contingency table. To examine if there was any skill acquisition during the study period, it was divided into four epochs and the data of the success rate, and the intubation time were compared between the epochs using the Kruskal-Wallis test and one-factor analysis of variance, respectively. P < 0.05 was considered statistically significant.
| Results |
|---|
|
|
|---|
|
|
|
|
During the intubation procedure, minor mucosal bleeding was recognized in 14 patients in the FastrachTM group, compared with 2 cases in the TrachlightTM group. Minor nasal bleeding was seen in 3 of 12 requiring fiberoptic laryngoscopy cases. No other complications such as dental injuries or unexpected respiratory and circulatory changes occurred during the procedure.
On postoperative day 7, neurological deterioration as compared to the preoperative state was noted in 2 cases in the TrachlightTM group, 1 case in the FastrachTM group, and 1 case with the awake fiberoptic technique. No patient complained of throat discomfort at this time in any group.
| Discussion |
|---|
|
|
|---|
Several previous reports have shown the usefulness of FastrachTM in patients with cervical spine disorders (1719); however, the studies were performed in simulated patients or were anecdotal reports, and there was no comparison with alternate devices. Successful tracheal intubation with FastrachTM depends on neck position (20,21). However, movements of the head and neck are limited in patients with cervical abnormalities. We believe that the decreased success rate with FastrachTM compared with the previous studies (22,23) is attributable to keeping a neutral position without neck movement.
In this study we chose a BlueLineTM tracheal tube for economical reasons in the FastrachTM group. This may be another reason for the decreased success rate in the FastrachTM group because the manufacturer recommends the use of a dedicated straight silicone tube for intubation through the FastrachTM for the best results (15).
In contrast, Hung et al. (15) reported that difficulty in tracheal intubation using the TrachlightTM does not appear to be influenced by anatomical variations of the upper airway. There was no correlation between intubation time and airway variables such as mandibular protrusion, mento-hyoid distance or Mallampati class. We therefore believe that the TrachlightTM may be more reliable than the FastrachTM in the patient whose head and neck are required to be in a neutral position.
Our intubation protocol allowed only two attempts, each within 30s in the TrachlightTM group. In the FastrachTM group, only one attempt was allowed for blind intubation through FastrachTM after the airway had been established within two attempts for insertion because we wanted to evaluate the reliability in the context of clinical simplicity and rapidity. This protocol seems more strict than those in previous studies regarding the usefulness of FastrachTM (22,23). However, our protocol may reflect actual clinical reliability of these devices.
The second choice of instruments was decided by the investigator when the intubation failed within the protocol. Most cases failed with FastrachTM were resolved with TrachlightTM (17/20). In contrast, two cases of failure with TrachlightTM were resolved with fiberoptic laryngoscopy. These results also suggest that TrachlightTM has an advantage of reliability over FastrachTM in such a time-limited situation.
Keller et al. (24) have reported that laryngeal mask devices exert greater pressures against the cervical vertebrae than does direct laryngoscopy. Kihara et al. (25) has reported that the intubating laryngeal mask can produce posterior displacement of the cervical spine. These data, plus our observation of less bleeding with the TrachlightTM, suggest that tracheal intubation using TrachlightTM may be a more gentle technique than the FastrachTM in the patient with a neutral position of the head and neck, although there are few data regarding precise cervical movement in the use of the TrachlightTM.
In conclusion, we demonstrated that, for well trained personnel, the TrachlightTM may be superior to the FastrachTM for orotracheal intubation in elective patients with cervical spine disorders, with respect to reliability, rapidity, and safety. Anesthesia providers responsible for securing the airway in patients with cervical spine disorders should be familiar with the TrachlightTM intubation technique.
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
B. J. Houde, S. R. Williams, A. Cadrin-Chenevert, F. Guilbert, and P. Drolet A Comparison of Cervical Spine Motion During Orotracheal Intubation with the Trachlight(R) or the Flexible Fiberoptic Bronchoscope Anesth. Analg., May 1, 2009; 108(5): 1638 - 1643. [Abstract] [Full Text] [PDF] |
||||
![]() |
J E Ollerton, M J A Parr, K Harrison, B Hanrahan, and M Sugrue Potential cervical spine injury and difficult airway management for emergency intubation of trauma adults in the emergency department--a systematic review Emerg. Med. J., January 1, 2006; 23(1): 3 - 11. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. P. Turkstra, R. A. Craen, D. M. Pelz, and A. W. Gelb Cervical Spine Motion: A Fluoroscopic Comparison During Intubation with Lighted Stylet, GlideScope, and Macintosh Laryngoscope Anesth. Analg., September 1, 2005; 101(3): 910 - 915. [Abstract] [Full Text] [PDF] |
||||
![]() |
K.-I Cheng, K.-S. Chu, S.-W. Chau, S.-L. Ying, H.-T. Hsu, Y.-L. Chang, and C.-S. Tang Lightwand-Assisted Intubation of Patients in the Lateral Decubitus Position Anesth. Analg., July 1, 2004; 99(1): 279 - 283. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|