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Anesth Analg 2001;92:1342-1346
© 2001 International Anesthesia Research Society

GENERAL ARTICLES

The Intubating Laryngeal Mask Airway After Induction of General Anesthesia Versus Awake Fiberoptic Intubation in Patients with Difficult Airways

Hwan S. Joo, MD, FRCPC, Sunil Kapoor, MD, FRCPC, D. Keith Rose, MD, FRCPC, and Viren N. Naik, MD

Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada

Address correspondence to Hwan Joo, MD, Department of Anaesthesia, St. Michael’s Hospital, 30 Bond Street, Toronto, Ontario, Canada M5B 1W8. Address e-mail to hwanjoomd{at}yahoo.com


   Abstract
Top
 Abstract
Introduction
 Material and Methods
 Results
 Discussion
 References
 
We performed the current study to compare tracheal intubation (TI) using awake fiberoptic intubation (AFOI) and TI using the intubating laryngeal mask airway (ILMA) in patients with difficult airway. Our hypothesis was that patients with difficult airways could be safely intubated after induction of anesthesia using the ILMA. After ethics approval and informed consent, 38 patients who were identified to have difficult airways were randomly assigned to AFOI or TI using the ILMA. Patients in the AFOI group had the usual sedation and airway topicalization. Patients in the ILMA group were induced with propofol for ILMA insertion and succinylcholine for TI. The first TI attempt was done blindly via the ILMA and all subsequent attempts were performed with fiberoptic guidance. All patients in the ILMA group were successfully ventilated. Successful TI was achieved in all patients in both groups. However, in 10% of the patients in the ILMA group, TI was achieved by a second anesthesiologist who was more experienced with the use of the ILMA. In a postoperative questionnaire, patients in the ILMA group were more satisfied with their method of TI (P < 0.01). The ILMA is a useful device in the management of patients with difficult airways and may be a valuable alternative to AFOI when AFOI is contraindicated or in the patient with the unanticipated difficult airway.

Implications: The intubating laryngeal mask airway is a useful device in the management of patients with difficult airways and may be a valuable alternative to awake fiberoptic intubation (AFOI) when AFOI is contraindicated or in the patient with the unanticipated difficult airway.


   Introduction
Top
 Abstract
 Introduction
Material and Methods
 Results
 Discussion
 References
 
Traditionally, for patients with predicted or proven difficult airways, establishment of a secure airway while the patient is awake has been advocated. As fiberoptic bronchoscopes (FOB) have become routinely available in most hospitals, awake fiberoptic intubation (AFOI) has emerged as the "gold standard" for patients with suspected or proven difficult airways. Many studies and case reports have illustrated the safety and effectiveness of AFOI (1–4). The difficult airway algorithm, devised in 1991 by the American Society of Anesthesiologists, supported this stance by emphasizing that patients with "difficult" airways should be intubated awake (5). However, AFOI has had some drawbacks in that it may not be performed in patients who are not cooperative or those who refuse it. AFOI has been associated with oxygen desaturation (6), tachycardia, and hypertension (3). Cases in which AFOI has led to life-threatening airway obstruction requiring emergency surgical airway have also been reported (7,8). Finally, AFOI has been associated with up to a 55% incidence of patient discomfort (9).

Recently, a new device, the intubating laryngeal mask airway (ILMA) has been introduced for airway management. The ILMA allows for confirmation of oxygenation and ventilation before tracheal intubation (TI) is attempted. Continuous ventilation can be maintained during TI attempts and the ILMA can be used as the sole airway without TI. For patients with normal airways, the ILMA has a ventilation success rate of 99%–100% and a TI success rate of 97%–99% (10–12). There have been numerous case reports describing the successful use of the ILMA for ventilation and subsequent TI in patients with difficult airways, after failed laryngoscopy and after failed FOB intubation (13–17). However, there have been no prospective controlled studies specifically on the use of the ILMA in patients with difficult airways.

The purpose of the present study was to compare AFOI with TI after induction of general anesthesia using the ILMA. Our primary hypothesis was that selected patients with documented or predicted difficult airways could be successfully and safely intubated after induction of anesthesia using the ILMA. The secondary hypothesis was that patients would be more satisfied with TI after induction of anesthesia.


   Material and Methods
Top
 Abstract
 Introduction
 Material and Methods
Results
 Discussion
 References
 
After institutional ethics approval, informed consent was obtained from all patients. ASA physical status I-III patients were recruited and randomly assigned into one of two groups, AFOI or TI with the ILMA. Patients were approached for the study if a noninvestigating anesthesiologist determined that they would require an AFOI based on clinical predictors or history of prior difficult intubation. These predictors included previous multiple or failed laryngoscopies, Cormack score >3, Mallampati score >3, retrognathia, thyromental distance <6 cm, and limited c-spine movement (18–21). Patients with unstable c-spine, morbid obesity (body mass index >35), history of difficult ventilation, or patients at risk for aspiration of gastric contents were excluded. Patients with mouth opening <2.5 cm (required for ILMA insertion) and patients with pathological abnormalities of the airway were also excluded.

Randomization was performed using computer-generated random numbers, enclosed in sealed envelopes. Statistical analysis was performed using Sigma Stat 2.0 (SPSS, Chicago, IL). Nonparametric indices, including oxygen saturation, anesthesiologists’ experiences, and all visual analogue scale (VAS) scores, were analyzed using Mann-Whitney U-test. Patient recall was analyzed using a Fisher’s exact test. Patients’ demographics, hemodynamic results, and time to TI were compared using unpaired Student’s t-tests. Parametric data were reported as mean ± SD and nonparametric data were presented as median with 25th–75th percentiles. A two-tailed P value of <0.05 was considered significant.

All patients were monitored continuously with pulse oximetry, five-lead electrocardiogram, and noninvasive blood pressure monitor. A difficult airway cart, which included multiple laryngeal mask airways (LMA), Combitubes® (The Kendall Company, Mansfield, MA), and cricothyroidotomy sets, was present during all study cases. The primary anesthesiologist was a fully trained anesthesiologist scheduled as the patient’s anesthesiologist for the surgery. One of the study investigators experienced with both AFOI and the ILMA (>50 cases for each) was present as the second anesthesiologist for all study cases. The study investigator intervened if patients became hemodynamically unstable, if TI by the patient’s primary anesthesiologist was unsuccessful after 20 min using either method, or if a fourth TI attempt was required in the ILMA group.

Patients in the AFOI group were given 0.2 mg of glycopyrrolate IV as an antisialogue on entering the operating room. Oxygen was administered via nasal prongs at 3 lpm. Midazolam and fentanyl were used for sedation. The dose was left to the discretion of the primary anesthesiologist. The mode of airway topicalization with lidocaine was also left up to the primary anesthesiologist and included various combinations of 4% lidocaine pledgets, nebulized lidocaine, 10% lidocaine spray, superior laryngeal nerve blocks, and transtracheal injection. All TI attempts were made orally using a standard 5 mm Pentax (Mississauga, ON, Canada) FOB and a 7 mm polyvinylchloride (PVC) endotracheal tube (ETT). On confirmation of TI by end-tidal CO2 (ETCO2) detection, general anesthesia was induced with propofol. If the AFOI was unsuccessful after 20 min had expired, the study investigator took over. If TI was unsuccessful in the next 10 min (30 min in total), the trial was categorized as a failure.

Patients in the ILMA group breathed with 100% oxygen for 3 min. General anesthesia without muscle relaxation was induced using a combination of midazolam, fentanyl, and propofol in doses determined by the primary anesthesiologist. On loss of consciousness and jaw relaxation, manual ventilation was initiated. If manual ventilation failed, the trial was to be categorized as a failure and the patient awoken for an AFOI after ventilation support via a conventional LMA or other airway adjunct. If manual ventilation was successful, a #4 ILMA was introduced in female patients and a #5 ILMA in male patients. If more than two adjustments of the ILMA were required for adequate ventilation, the trial was categorized as a failure and the patient awoken for an AFOI. Once adequate ventilation was achieved with the ILMA, the patient was paralyzed with succinylcholine (1 mg/kg). A single blind TI attempt (first attempt) was made with a standard 7-mm PVC ETT inserted "backward" with the concave curvature facing downwards (15). If resistance or esophageal intubation occurred, the ETT was removed and TI was reattempted (second total attempt at TI) with FOB guidance via the ILMA using a 5 mm Pentax FOB inserted into the ETT. A bronchoscope-ETT adapter was used during all FOB attempts to provide continuous positive pressure ventilation with 100% oxygen at a tidal volume of 400 mL and a rate of 12 breaths/min. Supplementary propofol was given as needed to maintain general anesthesia. If TI was still unsuccessful, the primary anesthesiologist reinserted the ILMA and a second attempt with FOB guidance (third total attempt at TI) was performed. If TI was still not successful or if 20 min had expired, the study investigator took over. The ILMA was reinserted and TI attempted with FOB guidance (fourth total attempt). Once TI was achieved, the ILMA was removed with the use of a second 7-mm ETT as a pusher (15). If TI was not achieved after four TI attempts or if 30 min in total had expired, the trial was categorized as a failure and the patient awoken for AFOI.

Hemodynamic variables and oxygen saturations were recorded at 1-min intervals. In the AFOI group, the time from initiation of airway topicalization to ETCO2 detection from the ETT was defined as the induction time. Tracheal intubation time, a proportion of the induction time, was defined as the time from initiation of FOB manipulation to ETCO2detection from the ETT. In the ILMA group, the induction time was defined as the time from administration of propofol to ETCO2 detection from the ETT. Tracheal intubation time was defined the time from when the ILMA was first picked up to ETCO2 detection from the ETT.

The patients’ primary anesthesiologists were given a questionnaire immediately after TI to assess experience, comfort, and safety with their randomized method of TI using a 10-point VAS score.

Patients were given a questionnaire that assessed patient satisfaction, sore throat, and hoarseness on a 10-point VAS score on postoperative day 1.


   Results
Top
 Abstract
 Introduction
 Material and Methods
 Results
Discussion
 References
 
Patient demographics, including the reason for entry into the study, were not different between the two groups (Table 1). Eighteen patients were enrolled into the AFOI group and 20 into the ILMA group.


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  		Table 1. Patient Demographics
 
There was a trend toward faster induction times in the ILMA group (672 ± 545 s) compared with the AFOI group (972 ± 331 s) (P = 0.05) ( Table 2). This reflected the time required for airway topicalization in the AFOI group. Tracheal intubation times were similar in both groups. The primary anesthesiologist successfully intubated the tracheas of all patients in the AFOI group. All patients were successfully ventilated with the ILMA (90% after one attempt and 100% after two attempts). Blind TI via the ILMA was successful in 50% of patients. A further 25% of the patients in the ILMA group were intubated with FOB guidance without changing or manipulating the ILMA. After reinsertion of the ILMA another 15% of the patients were intubated with FOB guidance by the primary anesthesiologist. Two patients (10%) in the ILMA group could not be intubated by the primary anesthesiologist but were successfully intubated by the study investigator.


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  		Table 2. Induction and Tracheal Intubation
 
Maximum heart rate and maximal blood pressure during anesthetic induction were similar in both groups. Minimum oxygen saturation was higher in the ILMA group at 97.5% (96%–98%) vs 94.5% (91%–96%) (P < 0.01). Oxygen saturation decreased to 62% and 84% in two patients in the AFOI group. In one patient in the ILMA group the oxygen saturation decreased to 85%.

The primary anesthesiologists had significantly more experience with AFOI than the ILMA (P < 0.01) ( Table 3). They were significantly more comfortable with AFOI (median 9.5; 25th–75th quartiles, 9–10) than the ILMA (median, 7.0; 25th–75th quartiles, 5–10) (P < 0.01). Primary anesthesiologists predicted higher patient satisfaction scores in the ILMA group (median, 8; 25th–75th quartiles, 8–10) vs the AFOI group (median, 5; 25th–75th quartiles, 4–7) (P < 0.01).


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  		Table 3. Primary Anesthesiologist Questionnaire
 
Patients had a significantly higher median VAS satisfaction score in the ILMA group at 10 (10–10) vs 8 (4–9) in the AFOI group (P < 0.01) ( Table 4). The satisfaction score did not correlate with the dose of midazolam or incidence of recall in the AFOI group. Recall of TI was significantly more in the AFOI group at 39% vs 0% in the ILMA group (P < 0.01). Sore throat and hoarseness were similar in both groups on postoperative day 1.


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  		Table 4. Postoperative Patient Questionnaire
 

   Discussion
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Discussion
References
 
The results of this study show that both AFOI and ILMA are associated with a high degree of success. TI was successful in all patients in both groups. No adverse event or morbidity was encountered in any of the patients in both groups. Hemodynamic response to TI and overall anesthetic induction times were similar in both groups.

Ventilation with the ILMA was successful in all patients within two attempts by operators with nominal ILMA experience. Even during prolonged TI attempts in the ILMA group, there was only one episode of transient hypoxemia, as ventilation was always maintained. This suggests that the ILMA may be a useful tool for ventilation in patients with difficult airways. Tracheal intubation after induction of anesthesia with the ILMA had some advantages over AFOI. Patients in the ILMA group had higher satisfaction scores, an infrequent incidence of recall, and no increase in morbidity such as sore throat or hoarseness.

The use of PVC ETT in the current study may be criticized, as they may be associated with a lower success rate, even when turned 180°, when compared with silicone ETT (22). Silicone ETT is also softer and may cause less trauma to the airway. However, PVC ETT are more readily accessible, disposable, and considerably less expensive (a PVC tube costs $2–3 vs $45–55 US for a silicone tube). The use of FOB via the ILMA and the ETT would also negate the possible advantages of using a silicone ETT in this study. We limited blind PVC intubation attempts to one. The FOB was used in all subsequent attempts to decrease the chance of airway trauma and increase success rates with subsequent intubation attempts.

There are two limitations to this study. First, there were many primary anesthesiologists with limited experience with the ILMA involved in TI in both the AFOI and the ILMA groups. This may have contributed to variability in induction times and success rates. However, the use of anesthesiologists with nominal experience may more closely reflect expected clinical results. Also, a second, more experienced anesthesiologist with more than 50 previous TI with the ILMA was always present to help if TI could not be performed within three attempts. The second limitation to this study is the sample size. All eligible patients in a two-year period were approached. Because of the infrequent incidence of patients with difficult airway with no exclusion criteria requiring AFOI, the number of consenting patients enrolled in the study was small. A multicentered study would be required for a larger sample size.

The primary anesthesiologist performed successful TI in all patients in the AFOI group. However, TI could not be successfully performed in 10% of the patients in the ILMA group by the primary anesthesiologist. TI was successfully performed by one of the study investigators who were more experienced with the ILMA without any problems. As a result of our small sample size, it would be unreasonable to suggest that ILMA can be routinely used for elective TI in patients with difficult airways by nominally experienced users. The fact that the primary anesthesiologists felt more comfortable with the AFOI than the ILMA may reflect their greater experience with AFOI and their inexperience with the ILMA.

For most patients who are calm and cooperative, there is no definitive advantage other than patient comfort for using the ILMA over AFOI. Patients who refuse AFOI or who may not be able to cooperate for AFOI may be candidates for TI with ILMA. Patients who are found to have difficult laryngoscopy after induction of general anesthesia but are easy to ventilate manually may be suitable for continuation of general anesthesia and TI using the ILMA. Until large-scale studies are performed on the safety of the ILMA for use on patients with difficult airways, it may be prudent to have two anesthesiologists available during induction of anesthesia if the ILMA is to be used on patients with difficult airways. The other option is to have an experienced nurse or respiratory technician helping the primary anesthesiologist. However, in both scenarios, experience must be gained with the ILMA before attempting to induce general anesthesia on patients with difficult airways.

In conclusion, the ILMA has shown a high success rate for ventilation and TI in patients with difficult airways. The ILMA is a useful device for managing patients with difficult airways and may be especially useful where AFOI is not possible. As with all airway adjuncts, experience should be gained before attempting to use the ILMA in patients with difficult airways.


   Acknowledgments
 
Supported, in part, by a grant from the Canadian Anesthesiologist’s Society.

We would like to thank Dr. Michael Kolton and Dr. Orlando Hung for their help in reviewing this manuscript.


   References
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Discussion
 References
 

  1. Messeter KH, Pettersson KI. Endotracheal intubation with the fibre-optic bronchoscope. Anaesthesia 1980; 35: 294–8.[Web of Science][Medline]
  2. Morris IR. Fibreoptic intubation. Can J Anaesth 1994; 41: 996–1007.[Web of Science][Medline]
  3. Ovassapian A, Yelich SJ, Dykes MH, Brunner EE. Blood pressure and heart rate changes during awake fiberoptic nasotracheal intubation. Anesth Analg 1983; 62: 951–4.[Free Full Text]
  4. Tan I, Wang CY. Fibreoptic intubation–a case series and brief review. Med J Malaysia 1993; 48: 200–6.[Medline]
  5. Benumof JL. Management of the difficult adult airway: with special emphasis on awake tracheal intubation [published erratum appears in Anesthesiology 1993;78:224]. Anesthesiology 1991; 75: 1087–110.[Web of Science][Medline]
  6. Fuchs G, Schwarz G, Baumgartner A, Kaltenbock F, et al. Fiberoptic intubation in 327 neurosurgical patients with lesions of the cervical spine. J Neurosurg Anesthesiol 1999; 11: 11–6.[Web of Science][Medline]
  7. McGuire G, el-Beheiry H. Complete upper airway obstruction during awake fibreoptic intubation in patients with unstable cervical spine fractures. Can J Anaesth 1999; 46: 176–8.[Web of Science][Medline]
  8. Shaw IC, Welchew EA, Harrison BJ, Michael S. Complete airway obstruction during awake fibreoptic intubation. Anaesthesia 1997; 52: 582–5.[Web of Science][Medline]
  9. Sutherland AD, Williams RT. Cardiovascular responses and lidocaine absorption in fiberoptic-assisted awake intubation. Anesth Analg 1986; 65: 389–91.[Abstract/Free Full Text]
  10. Baskett PJ, Parr MJ, Nolan JP. The intubating laryngeal mask. Results of a multicentre trial with experience of 500 cases. Anaesthesia 1998; 53: 1174–9.[Web of Science][Medline]
  11. Brain AI, Verghese C, Addy EV, et al. The intubating laryngeal mask. II: A preliminary clinical report of a new means of intubating the trachea. Br J Anaesth 1997; 79: 704–9.[Abstract/Free Full Text]
  12. Joo HS, Rose DK. The intubating laryngeal mask airway with and without fiberoptic guidance. Anesth Analg 1999; 88: 662–6.[Abstract/Free Full Text]
  13. Asai T, Shingu K. Tracheal intubation through the intubating laryngeal mask in a patient with a fixed flexed neck and deviated larynx. Anaesthesia 1998; 53: 1199–201.[Web of Science][Medline]
  14. Asai T, Okuda H, Shingu K. Use of the intubating laryngeal mask for tracheal intubation in three patients with difficult airways [in Japanese]. Masui 1999; 48: 419–20.[Medline]
  15. Joo H, Rose K. Fastrach–a new intubating laryngeal mask airway: successful use in patients with difficult airways. Can J Anaesth 1998; 45: 253–6.[Web of Science][Medline]
  16. Parr MJ, Gregory M, Baskett PJ. The intubating laryngeal mask: use in failed and difficult intubation. Anaesthesia 1998; 53: 343–8.[Web of Science][Medline]
  17. Watson NC, Hokanson M, Maltby JR, Todesco JM. The intubating laryngeal mask airway in failed fibreoptic intubation. Can J Anaesth 1999; 46: 376–8.[Web of Science][Medline]
  18. Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia 1984; 39: 1105–11.[Web of Science][Medline]
  19. Mallampati SR, Gatt SP, Gugino LD, et al. A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J 1985; 32: 429–434.[Web of Science][Medline]
  20. Nath G, Sekar M. Predicting difficult intubation–a comprehensive scoring system. Anaesth Intensive Care 1997; 25: 482–6.[Web of Science][Medline]
  21. Voyagis GS, Kyriakis KP, Roussaki-Danou K, Bastounis EA. Evaluating the difficult airway: an epidemiological study. Minerva Anestesiol 1995; 61: 483–9.[Medline]
  22. van Vlymen JM, Coloma M, Tongier WK, White PF. Use of the intubating laryngeal mask airway: are muscle relaxants necessary? Anesthesiology 2000; 93: 340–5.[Web of Science][Medline]
Accepted for publication January 19, 2001.




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Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins and Stanford University Libraries' HighWire Press®. Copyright 2001 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press