CJA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Abstract Freely available
Right arrow Résumé de cet Article
Right arrow Full Text (PDF)
Right arrow Submit a scholarly reply
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bhatnagar, S.
Right arrow Articles by Bhatnagar, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bhatnagar, S.
Right arrow Articles by Bhatnagar, N.
Canadian Journal of Anesthesia 52:641-645 (2005)
© Canadian Anesthesiologists' Society, 2005
Cardiothoracic Anesthesia, Respiration and Airway

The LMA FastrachTM facilitates fibreoptic intubation in oral cancer patients

[Le ML FastrachTM facilite l’intubation fibroscopique dans les cas de cancer de la bouche]

Sushma Bhatnagar, MD*, Seema Mishra, MD*, Rajeev Ranjan Jha, MD*, Amit K. Singhal, MD{dagger} and Naresh Bhatnagar, PhD*

* From the Department of Anaesthesiology, Institute Rotary Cancer Hospital, All India Institute of Medical Sciences; and
{dagger} the Department of Mechanical Engineering, Indian Institute of Technology, New Delhi, India.

Address correspondence to: Dr. Sushma Bhatnagar, 2, North Avenue, IIT-Hauz Khas, New Delhi-110016, India. E-mai: narbhat{at}hotmail.com; shumob{at}yahoo.com


   Abstract
TOP
 Abstract
Introduction
 Material and methods
 Results
 Discussion
 References
 
Purpose: To compare ease of endotracheal intubation with the Intubating Laryngeal Mask Airway (ILMA) tracheal tube (TT; for LMA-FastrachTM) and regular PVC TT (Portex) for nasotracheal fibreoptic intubation in oral cancer patients with a difficult airway.

Methods: 40 patients of physical status ASA I–II with a history of previous oral cancer surgery and/or postoperative radiotherapy scheduled for oral cancer surgery were randomly allocated by sealed envelopes to undergo tracheal intubation with either the ILMA TT or a standard TT. Ease of nasal passage of the TT and ease of tracheal intubation over the fibrescope was assessed. Peak airway pressures were assessed intraoperatively and postoperatively for 12 hr.

Results: The use of the ILMA TT increased the ease of nasotracheal intubation by increasing the percentage of successful tube placements at the first attempt (80%) in comparison with standard TT (35%); (P < 0.05). Peak airway pressures were found to remain low with the ILMA TT. None of the patients experienced any airway related complications.

Conclusions: Use of a soft, flexible, nonkinking ILMA TT with a tapered tip design facilitates passage into the trachea over a fibreoptic bronchoscope and allows maintenance of lower airway pressures. The ILMA TT may be a useful adjunct for management of the difficult airway in oral cancer surgery.


   Introduction
TOP
 Abstract
 Introduction
Material and methods
 Results
 Discussion
 References
 
TRACHEAL intubation with the aid of fibreoptic bronchoscope (FOB) has improved the anesthesiologist’s ability to manage a difficult airway in oral cancer surgery. Still, passage of the tracheal tube (TT) over the FOB may be difficult.1 Resistance in response to advancement of the tube may be encountered at the laryngeal level.2 This is a serious problem that can result in laryngeal trauma as well as delayed or failed intubation, and has potential to cause arterial desaturation.3 The surgical procedure in oral cancer surgery involves sharing the same field by surgeons, which limits the anesthesiologist’s access to the airway.4 The procedure also requires frequent changes in positioning of the head and neck, which may cause kinking of the extra nasal portion of the TT.

Spiral wound silicon rubber tubes, because of their greater flexibility, facilitate orotracheal and nasotracheal fibreoptic intubation.5,6 Design of the TT tip7 and size of the tube8 have also been suggested to facilitate passage of the TT over the FOB. The Intubating Laryngeal Mask Airway TT (ILMA TT; LMA FastrachTM endotracheal tube; (Laryngeal Mask Company Ltd., Nicosia, Cyprus) features flexibility, a tapered tip and non-kinking design even with sharp angulations. Use of the ILMA TT for fibreoptic orotracheal intubation has been shown to facilitate rapid atraumatic fibreoptic orotracheal intubation.9 The aim of the current study was to compare the ease of intubation between the ILMA TT (TT for LMA-FastrachTM) and regular PVC TT (Portex) for nasotracheal fibreoptic intubation in oral cancer patients with a difficult airway.


   Material and methods
TOP
 Abstract
 Introduction
 Material and methods
Results
 Discussion
 References
 
After institutional Research Ethics Committee approval, 40 patients ASA physical status I–II aged 18 to 60 yr scheduled to undergo elective surgery for oral cancer under general anesthesia with nasotracheal intubation were included. Specifically included were patients with a history of prior surgery and/or radiotherapy for oral cancer with probability of difficult intubation. After obtaining written informed consent, patients were randomly allocated using labelled, sealed envelopes to undergo endotracheal intubation with either the ILMA TT (Group 1) or with a standard TT tube (Portex Tracheal Tube, Sims Portex Limited, Hythe, Kent, UK); (Group 2).

Patients were premedicated with oral diazepam 5 or 10 mg on the night before and again on the morning of surgery. Glycopyrrolate 0.2 mg im was given to all patients 45 min before surgery. Oxymetazoline nasal drops were instilled in both nostrils two to three times 45 min before the scheduled time of operation. Preoxygenation was provided with 100% oxygen and morphine 0.1 mg•kg–1 iv was administered. Anesthesia was induced with thiopentone or propofol in a dose sufficient to abolish eyelash reflex while at the same time 50% nitrous oxide in oxygen with increasing concentrations of halothane 0.5 to 3% volume were administered. A nasal airway (6.5–7.0 mm) was inserted in the nostril opposite to the one through which intubation was planned, and the breathing circuit was attached to it. After confirming the adequacy of positive pressure ventilation with the nasal airway, a neuromuscular blocking drug was administered and positive pressure ventilation continued. TT 7 mm were used in females, and 7.5 mm diameter tubes in males. During intubation, the patient’s jaw was lifted upwards and forward by an assistant to improve visualization of the larynx, and the position was maintained until the TT was inserted successfully. Anesthesia was maintained with 60 to 70% nitrous oxide in oxygen, isoflurane, morphine and vecuronium. Patients were kept in the intensive care unit (ICU) for at least 24 hr. In all patients nasotracheal intubation was maintained overnight and the trachea was extubated the next day. Intubations were performed by a single anesthesiologist and graded on an arbitrary subjective scale (Table IGo). Ease of tracheal intubation over the fibrescope was scored according to four grades (Table IIGo). Peak airway pressure (PAP) was recorded every hour for 12 hr after intubation. However, during surgical procedures PAP was closely observed for eight to ten hours on average.


View this table:
[in this window]
[in a new window]
  		TABLE I Scoring system for ease of passage of the tracheal tube through the nose
 

View this table:
[in this window]
[in a new window]
  		TABLE II Scoring system for ease of tracheal intubation
 
Statistics
Twenty patients in each group were randomized. A post hoc analysis for the power of the study was undertaken using the correlation coefficient (r) from 0.55 to 0.91, alpha ({alpha}) = 0.05, and means and standard deviations for pre- and post-observations of the data separately. The power was > 90% (STATA 8.0 package, Stata Corp LP, Texas, TX, USA).

Demographic data are expressed as mean ± standard deviation. Unpaired t tests were used to compare continuous data and a Chi-square test was applied to nominal data. Airway pressures between groups were compared by a two-way ANOVA with post hoc analysis using a Bonferroni test. The Mann Whitney U test was used to compare ease of insertion between the two groups. SPSS 7.5 (SPSS Inc., Woking, UK) and STATA 8.0 statistical packages were used for the analyses. A P value (< 0.05) was considered significant.


   Results
TOP
 Abstract
 Introduction
 Material and methods
 Results
Discussion
 References
 
The two groups were similar with respect to age, weight and gender (Table IIIGo).


View this table:
[in this window]
[in a new window]
  		TABLE III Patient characteristics (mean ± SD for age and sex)
 
There was no statistically significant difference in ease of nasal passage between both groups (Table IVGo). One patient in Group 1 required a one-size smaller tube due to failure of passage of the designated size tube.


View this table:
[in this window]
[in a new window]
  		TABLE IV Ease of nasal insertion and of tracheal intubation
 
There was a significant difference in ease of intubation between both groups (P = 0.02) (Table IVGo). The number of successful tube placements upon first attempt was higher in Group 1 (80%) in comparison to Group 2 (35%); (P = 0.02). There was one failure in Group 2 which was ultimately resolved after changing the standard PVC TT to the ILMA TT.

Peak airway pressures were significantly higher between hours three and seven in Group 2 (Figure 1Go). One patient in each group had minor nasal bleeding during passage of the tube which in neither case interfered with intubation, and stopped immediately after an additional two to three drops of oxymetazoline. Three patients in Group 1 and one patient in Group 2 had minor epistaxis during extubation, which stopped with nasal compression and oxymetazoline drops. There were no airway related complications in any patient during their 24-hr ICU stay.



View larger version (33K):
[in this window]
[in a new window]
  		FIGURE 1 Peak airway pressures as a function of time.

 

   Discussion
TOP
 Abstract
 Introduction
 Material and methods
 Results
 Discussion
References
 
Fibreoptic intubation has a well-established role in anesthetic practice and has revolutionized the management of patients presenting with known or suspected difficult intubation. This study demonstrates that following placement of the FOB into the trachea, intubation is easier with the ILMA TT than with a standard PVC TT. Also peak airway pressures are lower with the ILMA TT. The standard PVC TT is not reinforced with metal wire, as is the ILMA TT. Due to lack of reinforcement, the standard PVC TT tends to kink when bent which reduces the cross sectional area and in turn increases airway pressure. However tube reinforcement as with the ILMA TT prevents kink formation and helps to ensure that airway pressures remain constant. Postoperatively, patients tolerated the tube well and the incidence of epistaxis was similar in both groups.

The potential for a difficult airway in oral cancer patients is largely due to limited head and neck mobility and position, limited mouth opening, limited upper airway open space resulting from tumour, edema or previous surgery, distorted anatomy of the airway by tumour expansion or previous surgery, and fixation of the tissue of oral cavity, pharynx or larynx by tumours, surgical scar or radiation fibrosis.10 Factors associated with difficult railroading of the TT over the fibrescope include: large differences in diameter between fibrescope and TT,8 flexibility of the tube,5,6 tube tip design,5,7,9,11 and the technique and experience of the operator.

The ILMA TT, being made of silicone-based plastic, is soft and flexible and has a specifically designed tapered end as shown in Figure 2Go. This reduces the gap between the fibrescope and the tube. For this reason the ILMA TT has been shown to facilitate orotracheal intubation.12 Our study lends further evidence to its usefulness in nasotracheal fibreoptic intubation. In a previous study where ILMA TT was used to facilitate fibreoptic intubation, ‘holdup’ of the ILMA TT was not observed in any of the 18 patients. Though it was anticipated that a nasotracheal intubation would be easier, we encountered ‘holdup’ in four patients requiring slight withdrawal and rotation of the tube. These obstructions to TT advancement have been due to a different cohort of patients, as previous studies were conducted in patients with normal airways, whereas our study was performed in oral cancer patients with a high probability of difficult intubation. Similarly, another TT known as Parker Flex-Tip Tube is associated with greater initial success rate of endotracheal intubation when compared to the standard TT, due to its novel tip design.13



View larger version (58K):
[in this window]
[in a new window]
  		FIGURE 2 Intubation laryngeal tracheal tube (FastrachTM) and standard tracheal tube (Portex).

 
Despite its advantages, the spiral wound tube has been associated with serious airway obstruction. Biting of the tube has been shown to cause permanent narrowing of the lumen14,15 but this is not a concern with the nasotracheal intubation, as in the case of the curreent study. Aneurysmal dilatation of the cuff also has been reported to cause obstruction, although new materials decrease this risk. One recent case report suggests that if a disposable tube is reused, obstruction may ensue and more importantly fibreoptic examination may fail to reveal the obstruction.16 With spiral wound tubes obstruction can occur due to bending at the connector,17 but inserting the connector up to the point where the spiral starts makes the occlusion unlikely. The ILMA TT has the additional advantage of a Murphy eye, in comparison to other flexometalic tubes, which prevent obstruction when the TT impinges on the tracheal wall.

In conclusion, our data suggest that the use of the soft, flexible, non-kinking ILMA TT with tapered tip design facilitates easy passage over a FOB into the trachea. Maintenance of the airway with this tube is also associated with lower airway pressures. Use of the ILMA TT should therefore be considered in the airway management of patients presenting for oral cancer surgery.


   Acknowledgments
 
We thank Dr. Rajveer Singh, Scientist-C, Dept of Statistics, AIIMS, New Delhi for assisting with the statistical analysis.


   Footnotes
 
Accepted for publication August 17, 2004. Revision accepted February 14, 2005.


   References
TOP
 Abstract
 Introduction
 Material and methods
 Results
 Discussion
 References
 
1 Brull SJ, Wiklund R, Ferris C, Connelly NR, Ehrenwerth J, Silverman DG. Facilitation of fiberoptic orotracheal intubation with a flexible tracheal tube. Anesth Analg 1994; 78: 746–8.[Abstract/Free Full Text]

2 Katsnelson T, Frost EA, Farcon E, Goldiner PL. When the endotracheal tube will not pass over the flexible fiberoptic bronchoscope (Letter). Anesthesiology 1992; 76: 151–2.[Medline]

3 Hughes S, Smith JE. Nasotracheal tube placement over the fiberscope laryngoscope. Anaesthesia 1996; 51: 1026–8.[Medline]

4 Beckers HL. Use of stabilized, armoured endotracheal tube in maxillofacial surgery. Anesthesiology 1982; 56: 309–10.[Medline]

5 Hakala P, Randell T, Valli H. Comparison between tracheal tubes for orotracheal fibreoptic intubation. Br J Anaesth 1999; 82: 135–6.[Abstract/Free Full Text]

6 Ovassapian A, Yelich SJ, Dykes MH, Brunner EE. Fiberoptic nasotracheal intubation–incidence and causes of failure. Anesth Analg 1983; 62: 692–5.[Free Full Text]

7 Jones HE, Pearce AC, Moore P. Fibreoptic intubation. Influence of tracheal tube tip design. Anaesthesia 1993; 48: 672–4.[Medline]

8 Koga K, Asai T, Latto IP, Vaughan RS. Effect of the size of a tracheal tube and the efficacy of the use of the laryngeal mask for fibrescope-aided tracheal intubation. Anaesthesia 1997; 52: 131–5.[Medline]

9 Greer JR, Smith SP, Strang T. A comparison of tracheal tube tip designs on the passage of an endotracheal tube during oral fiberoptic intubation. Anesthesiology 2001; 94: 729–31.[Medline]

10 Dougherty TB, Clayman GL. Airway management of surgical patients with head and neck malignancies. Anesthesiol Clin North America 1998; 16: 547–62.

11 Makino H, Katoh T, Kobayashi S, Bito H, Sato S. The effects of tracheal tube tip design and tube thickness on laryngeal pass ability during oral tube exchange with an introducer. Anesth Analg 2003; 97: 285–8.[Abstract/Free Full Text]

12 Lucas DN, Yentis SM. A comparison of the intubating laryngeal mask tracheal tube with a standard tracheal tube for fibreoptic intubation. Anaesthesia 2000; 55: 358–61.[Medline]

13 Kristensen MS. The Parker Flex-Tip tube versus a standard tube for fiberoptic orotracheal intubation. Anesthesiology 2003; 98: 354–8.[Medline]

14 Spiess BD, Rothenberg DM, Buckley S. Complete obstruction of armored endotracheal tubes (Letter). Anesth Analg 1991; 73: 95–6.

15 Brusco L Jr, Weissman C. Pharyngeal obstruction of a reinforced orotracheal tube. Anesth Analg 1993; 76: 653–4.[Abstract/Free Full Text]

16 Paul M, Dueck M, Kampe S, Petzke F. Failure to detect an unusual obstruction in a reinforced endotracheal tube with fiberoptic examination. Anesth Analg 2003; 97: 909–10.[Abstract/Free Full Text]

17 Cohen DD, Dillon JB. Hazards of armored endotracheal tubes. Anesth Analg 1972; 51: 856–8.[Free Full Text]





This Article
Right arrow Abstract Freely available
Right arrow Résumé de cet Article
Right arrow Full Text (PDF)
Right arrow Submit a scholarly reply
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bhatnagar, S.
Right arrow Articles by Bhatnagar, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bhatnagar, S.
Right arrow Articles by Bhatnagar, N.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS