Awake tracheal intubation through the intubating laryngeal mask airway in a patient with halo traction

PURPOSE: To report a case of awake tracheal intubation through the intubating laryngeal mask airway (ILMA) in a patient with halo traction. Clinical features: A 16-yr-old, 40 kg, boy with atlanto-occipital instability and halo traction was scheduled for surgery under general anesthesia. The head of the patient was fixed in a position of flexion and extension was impossible. Cranial magnetic resonance imaging revealed that pharyngeal and laryngeal axes were aligned, but that the oral axis was in an extreme divergent plane. The tongue and oropharynx were anesthetized with 10% lidocaine spray and bilateral superior laryngeal nerve blockade was performed. Under sedation, awake orotracheal intubation via ILMA was successful. Fibreoptic bronchoscopy has been recommended for awake tracheal intubation in such patients. Other techniques, such as use of the Bullard laryngoscope have been described also but awake tracheal intubation through the ILMA in patients with a halo device in situ has seldom been reported in the medical literature. CONCLUSION: Airway management of patients with cervical spine instability includes adequate preoperative evaluation of the airway and choosing the appropriate intubation technique. We suggest that the ILMA may be an adequate alternative for awake tracheal intubation in patients with an unstable cervical spine and cervical immobilization with a halo device.     

The intubating laryngeal mask airway after induction of general anesthesia versus awake fiberoptic intubation in patients with difficult airways

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.     

A modified method for intubation of a patient with ankylosing spondylitis using intubating laryngeal mask airway (LMA-Fastrach)--a case report

We present an instance of successful use of an intubating laryngeal mask airway (LMA-Fastrach) and a Cook airway exchanger (CAE) for ventilation and intubation in a patient with severe ankylosing spondilitis (AS) receiving total hip arthroplasty. This measure may serve as an effective alternative for airway management in patients with difficult airway. A 61-year-old male was scheduled for right total hip arthroplasty because of degenerative osteoarthritis. He had been suffering from extensive ankylosing spondylitis, with the cervical spine markedly fixed in anterior flexion. Besides he could not open his mouth widely (35 mm when fully open) also because of ankylosis of jaw. Although we advised an awake fiberoptic tracheal intubation for anesthesia but he refused owing to a previous painful experience. After induction of anesthesia with glycopyrrolate, fentanyl, thiamylal sodium and succinylcholine, we inserted a # 5 Fastrach ILMA for primary airway maintenance. Then through the lumen of the ILMA we introduced the CAE as a guide for endotracheal tube (ETT) intubation. After applying the RAPI-FIT adapter to the CAE, we connected it to the capnography monitor for the confirmation of airway. We finally inserted an endotracheal tube into the trachea using the CAE as a guide. The whole procedure was uneventful and smooth. In sum, the modified Fastrach intubation method may facilitate tracheal intubation in patients with severe ankylosing spondilitis. It may be an alternative way for successful airway management in patients with difficult airway.     

Comparison of the intubating laryngeal mask airway with the fiberoptic intubation in anticipated difficult airway management

BACKGROUND: The intubating laryngeal mask airway (ILMA; Fastrach; Laryngeal Mask Company, Henley-on-Thames, UK) may provide an alternative technique to fiberoptic intubation (FIB) to facilitate the management of the anticipated difficult airway. The authors therefore compared the effectiveness of the ILMA with FIB in patients with anticipated difficult intubation. METHODS: One hundred patients, with at least one difficult intubation criteria (Mallampati class III or IV, thyromental distance < 65 mm, interincisor distance < 35 mm) were enrolled (FIB group, n = 49; ILMA group, n = 51) in this prospective randomized study. Anesthesia was induced with propofol and maintained with alfentanil and propofol after an efficient mask ventilation has been demonstrated. The success of the technique (within three attempts), the number of attempts, duration of the successful attempt, and adverse events (oxygen saturation < 90%, bleeding) were recorded. RESULTS: The rate of successful tracheal intubation with ILMA was 94% and comparable with FIB (92%). The number of attempts and the time to succeed were not significantly different between groups. In case of failure of the first technique, the alternative technique always succeeded. Failures in FIB group were related to oxygen desaturation (oxygen saturation < 90%) and bleeding, and to previous cervical radiotherapy in the ILMA group. Adverse events occurred significantly more frequently in FIB group than in ILMA group (18 vs. 0%, P < 0.05). CONCLUSION: The authors obtained a high success rate and comparable duration of tracheal intubation with ILMA and FIB techniques. In patients with previous cervical radiotherapy, the use of ILMA cannot be recommended. Nevertheless, the use of the ILMA was associated with fewer adverse events.     

The intubating laryngeal mask airway does not facilitate tracheal intubation in the presence of a neck collar in simulated trauma

Tracheal intubation must be performed with great care in the multiply injured patient when it must be assumed that the cervical spine may be damaged. Use of conventional direct laryngoscopy usually requires removal of the neck collar and manual in-line stabilization of the head and neck. The intubating laryngeal mask (ILMA) has been designed to facilitate tracheal intubation in the neutral position. We used the ILMA to intubate the trachea in 10 patients wearing a neck collar and with cricoid pressure applied in a simulated trauma scenario. The ILMA was difficult to insert and ventilation proved difficult. In only two patients was intubation successful. These problems were probably caused by the neck collar strap under the chin lifting up and tipping the larynx anteriorly. On the basis of these findings, ILMA use in a subject wearing a neck collar cannot be recommended.      

Awake insertion of the fibreoptic intubating LMA CTrach in three morbidly obese patients with potentially difficult airways

The Intubating Laryngeal Mask Airway (ILMA) is a supraglottic airway that facilitates ventilation and blind tracheal intubation. The LMA CTrach is functionally identical to the ILMA, but has an integrated fibreoptic bundle that provides a view of the larynx. This enables visualisation of tracheal intubation while delivering 100% oxygen, with or without an inhalational anaesthetic. We report awake insertion of the CTrach in three morbidly obese patients (BMI 60-63) with known or anticipated difficult airways. Pre-operatively, patients were given midazolam and glycopyrrolate intravenously, and then in the operating theatre the airway was anaesthetised with topical lidocaine 4%. The CTrach was inserted into the oropharynx of the still-awake patient, the vocal cords were visualised, and anaesthetic induction was commenced with sevoflurane and spontaneous ventilation. Neuromuscular blockers were not used and we were able to see the vocal cords during the entire anaesthetic induction and intubation.     

Using the intubating laryngeal mask airway for ventilation and endotracheal intubation in anesthetized and unparalyzed acromegalic patients

Airway management may be difficult in acromegalic patients. The purpose of the study was to evaluate the intubating laryngeal mask airway (ILMA) as a primary tool for ventilation and intubation in acromegalic patients. Twenty-three consenting consecutive adult acromegalic patients presenting for transsphenoidal resection of pituitary adenoma were enrolled in the study. Anesthesia was induced using propofol (1.5 mg/kg followed by 0.5-mg/kg increments); the ILMA was inserted when the bispectral index fell below 50. The ILMA was successful as a primary airway for oxygenation and ventilation at the first attempt for 21 (91%) patients, while 2 (9%) patients required a second attempt. Patient movement was noticed in five (21.7%) of the patients during ILMA insertion. An attempt at tracheal intubation through the ILMA was performed following administration of a mean 395 +/- 168-mg dose of propofol. Overall success rates for tracheal intubation were 82% (19 patients). The first-attempt success rate for tracheal intubation was 52.6% (10 patients), second- and third-attempt success rates were 42.1% (8 patients) and 5.3% (1 patient), respectively. Coughing or movement during intubation was observed in 12 (63.2%) of the patients. Direct laryngoscopy permitted intubation in three cases and blind intubation using a bougie in the fourth case. ILMA can be used as a primary airway for oxygenation in acromegalic patients (manual bag ventilation), but the rate of failed blind intubation through the ILMA precludes its use as a first choice for elective airway management.     

The intubating laryngeal mask airway with and without fiberoptic guidance

We conducted this feasibility study using the intubating laryngeal mask airway (ILMA) and a polyvinyl chloride tracheal tube to compare success rates, hemodynamic effects, and postoperative morbidity with two methods of tracheal intubation. After ethics approval and informed consent, 90 healthy ASA physical status I or II women with normal airways were enrolled in the randomized, controlled study. After a standardized inhaled anesthesia induction protocol, tracheal intubations using ILMA with fiberoptic guidance (ILMA-FOB) and ILMA inserted blindly without fiberoptic guidance (ILMA-Blind) were compared with the control group of direct laryngoscopy (laryngoscopy group). All 90 patients were successfully ventilated. For tracheal intubation, success rates were equal in all three groups (97%). Total intubation times were longer for the ILMA-FOB group (77 s versus 48.5 s for laryngoscopy and 53.5 s for ILMA-Blind). The laryngoscopy group had a larger increase in mean arterial blood pressure to tracheal intubation. There were no differences in postoperative sore throat or hoarseness among the groups. In conclusion, success rates are equally high for tracheal intubation using ILMA-Blind and ILMA-FOB techniques in women with normal airways. IMPLICATIONS: The intubating laryngeal mask airway (ILMA) can be used as a primary airway for oxygenation and ventilation. Both methods of tracheal intubation using the ILMA were equally successful. Postoperative morbidity in the ILMA groups was similar to that in the laryngoscopy group. For women with normal airways, both the ILMA inserted blindly and the ILMA with fiberoptic guidance are suitable alternatives to laryngoscopy for tracheal intubation.     

Elective oral tracheal intubation in cervical spine-injured adults

There is controversy regarding the optimal mode of elective tracheal intubation in the patient with an unstable cervical spine following trauma. A ten-year review of 150 patients with traumatic cervical spine injuries with well-preserved neurological function, presenting for operative stabilization, was conducted to compare neurological outcome with the mode of tracheal intubation. Preoperative neurological deficits were identified in 49 patients (33%); most were single-level radiculopathies. Intubation occurred after induction of general anaesthesia in 83 patients (55%) and in 67 patients (45%) the tracheas were intubated with the patient awake. One hundred and six patients (71%) underwent oral tracheal intubation and 44 underwent nasal tracheal intubation. Ten intubations were deemed to be difficult requiring more than one attempt to effect intubation. Cervical spine immobilization during intubation was documented in 86 patients (57%). Weighted traction or manual in-line traction were the two manoeuvres most commonly employed to maintain spinal alignment during intubation. After surgery, two patients had new neurological deficits. There were no differences in neurological outcome whether intubation was performed while the patient was awake or under general anaesthesia, or comparing oral tracheal intubation with all other techniques (P = 0.5, Fisher exact test). Also, in-line traction did not affect neurological outcome. Oral tracheal intubation with in-line stabilization, either performed after induction of general anaesthesia or with the patient awake, remains an excellent option for elective airway management in patients with cervical spine injuries.     

The LMA Fastrach™ facilitates fibreoptic intubation in oral cancer patients

PURPOSE: To compare ease of endotracheal intubation with the Intubating Laryngeal Mask Airway (ILMA) tracheal tube (TT; for LMA-Fastrach) 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.     

The intubating laryngeal mask airway: an initial assessment of performance

A new prototype of the laryngeal mask airway (LMA), the intubating laryngeal mask airway (ILMA), was used to facilitate tracheal intubation in 100 fasted patients presenting for elective surgery. Alignment of the ILMA with the larynx was assessed fibreoptically before intubation without the investigator performing the intubation being aware of the view score. Ease of intubation correlated with the view obtained and with the degree of manipulation of the ILMA needed to achieve tracheal intubation. Intubation was successful in 93 patients. Of the seven intubation failures, five occurred in the first 20 patients. Conventional connection to the breathing system and ventilation of the lungs of the patients were possible throughout the intubation procedure.      

Intra-ocular pressure changes associated with intubation with the intubating laryngeal mask airway compared with conventional laryngoscopy

This open, prospective, randomised study was designed to evaluate the changes in intra-ocular pressure and haemodynamics after tracheal intubation using either the intubating laryngeal mask airway (ILMA) or direct laryngoscopy. Sixty adult patients, ASA physical status 1 or 2 with normal intra-ocular pressure were randomly allocated to one of the two techniques. Anaesthesia was induced with propofol followed by rocuronium. Tracheal intubation was performed using either the ILMA or Macintosh laryngoscope. Intra-ocular pressure, heart rate and blood pressure were measured immediately before and after tracheal intubation and then minutely for five minutes. In the laryngoscopy group there was a significant increase in intra-ocular pressure (from 7.2+/-1.4 to 16.8+/-5.3 mmHg, P<0.01), which did not return to pre-intubation levels within five minutes, and also in mean arterial pressure after tracheal intubation, which returned to baseline levels after five minutes. In the ILMA group there were no significant changes in intra-ocular pressure (from 7.6+/-1.8 to 10.4+/-2.8 mmHg, P >0.05) or mean arterial pressure after tracheal intubation. Time to successful intubation was longer with the ILMA, 56.8+/-7.8 seconds, compared with the laryngoscopy group, 33+/-3.6 seconds (P<0.01). Mucosal trauma was more frequent with the ILMA (eight of 30) compared with the laryngoscopy group (three of 30) (P<0.01). The postoperative complications were comparable. In terms of minimising increases in intra-ocular pressure and blood pressure, we conclude that the ILMA has an advantage over direct laryngoscopy for tracheal intubation.     

Intubating laryngeal mask airway allows tracheal intubation when the cervical spine is immobilized by a rigid collar

Background. An intubating laryngeal mask airway (ILMA) facilitatestracheal intubation with the neck in neutral position, whichis similar to the neck position maintained by a rigid cervicalcollar. However, a cervical collar virtually obliterates neckmovement, even small movements that normally facilitate airwayinsertion. We therefore tested the hypothesis that the ILMAwill allow tracheal intubation even in patients wearing a rigidcervical collar. Methods. We performed blind tracheal intubation via an ILMAunder general anaesthesia in 50 patients with a rigid Philadelphiacollar in place undergoing cervical spine surgery and 50 generalsurgical patients. Time required for intubation, intubationsuccess rate, and numbers and type of adjusting manoeuvres usedwere recorded. Results. Inter-incisor distance was significantly smaller (4.1(0.8) vs 4.6 (0.7) cm, mean (SD), P<0.01) and Mallampatiscores were significantly greater (P<0.001) in the patientswith collars. ILMA insertion took longer (30 (25) vs 22 (6)s), more patients required two insertion attempts (15 vs 3;P<0.005), and ventilation adequacy with ILMA was worse (P<0.05)in collared patients. However, there were no significant differencesbetween the collars and control patients in terms of total timerequired for intubation (60 (41) vs 50 (30) s), number of intubationattempts, overall intubation success rate (96 vs 98%), or theincidence of intubation complications. Conclusions. Blind intubation through an ILMA is thus a reasonablestrategy for controlling the airway in patients who are immobilizedwith a rigid cervical collar.     

Reflex responses to insertion of the intubating laryngeal mask airway,intubation and removal of the ILMA

We studied 21 patients (ASA 1 or 2) to investigate the skin vasomotor reflex (SVmR) and haemodynamic responses to insertion of an intubating laryngeal mask airway (ILMA), tracheal intubation using the ILMA and removal of the ILMA. Anaesthesia was induced with fentanyl, midazolam, vecuronium and nitrous oxide. A size 4 ILMA was inserted using the standard technique, and a silicone reinforced tracheal tube (7.5 mm, ID) was passed through it. After confirming successful intubation, the ILMA was removed using the stabilizing rod. The three procedures were performed at approximately one-minute intervals. Insertion of the ILMA, intubation and removal of the ILMA all significantly reduced the skin blood flow on the ring finger in all patients. The mean amplitudes of the SVmR were 0.46 (SD 0.29), 0.54 (0.32) and 0.68 (0.21) respectively. The magnitude of the SVmR and the haemodynamic changes induced by removal of the ILMA were significantly larger than those accompanying the other two procedures. Use of the ILMA for intubation and removal of the ILMA produces three stimuli and the removal of the ILMA produces the greatest response.     

Intubating Laryngeal Mask Airway in Morbidly Obese and Lean Patients: A Comparative Study

Background: The intubating laryngeal mask airway (ILMA) was designed using the characteristics of healthy-weight subjects but was shown to be an effective airway device in morbidly obese patients. The authors compared airway management quality in morbidly obese and lean patients with use of the ILMA.

Methods: Fifty morbidly obese and 50 lean patients (mean body mass indexes, 42 and 27 kg/m2, respectively) were enrolled in this prospective study. After induction of general anesthesia, characteristics of airway management were judged on safety and efficiency parameters, including success rate at ventilation and intubation and airway management quality criteria, such as the number of patients who required adjustment maneuvers, the number of failed tracheal intubation attempts, the total duration of airway management, and an overall difficulty visual analog scale score.

Results: The ILMA was successfully inserted and adequate ventilation through the ILMA was achieved in all 100 patients. The success rates of tracheal intubation through the ILMA were similar in obese and lean patients (96% and 94%, respectively). The numbers of failed blind tracheal access attempts and patients who required airway-adjustment maneuvers were significantly reduced in obese patients as compared with lean patients. Four obese patients experienced transient episodes of oxygen desaturation (oxygen saturation < 90%) before adequate bag ventilation was established with the ILMA.     

Intubating laryngeal mask airway in morbidly obese and lean patients: a comparative study

BACKGROUND: The intubating laryngeal mask airway (ILMA) was designed using the characteristics of healthy-weight subjects but was shown to be an effective airway device in morbidly obese patients. The authors compared airway management quality in morbidly obese and lean patients with use of the ILMA. METHODS: Fifty morbidly obese and 50 lean patients (mean body mass indexes, 42 and 27 kg/m, respectively) were enrolled in this prospective study. After induction of general anesthesia, characteristics of airway management were judged on safety and efficiency parameters, including success rate at ventilation and intubation and airway management quality criteria, such as the number of patients who required adjustment maneuvers, the number of failed tracheal intubation attempts, the total duration of airway management, and an overall difficulty visual analog scale score. RESULTS: The ILMA was successfully inserted and adequate ventilation through the ILMA was achieved in all 100 patients. The success rates of tracheal intubation through the ILMA were similar in obese and lean patients (96% and 94%, respectively). The numbers of failed blind tracheal access attempts and patients who required airway-adjustment maneuvers were significantly reduced in obese patients as compared with lean patients. Four obese patients experienced transient episodes of oxygen desaturation (oxygen saturation < 90%) before adequate bag ventilation was established with the ILMA. CONCLUSION: The authors confirmed that the ILMA was an efficient airway device for airway management of both lean and obese patients. In the conditions of this study, the authors observed that airway management with the ILMA was simpler in obese patients as compared with lean patients.     

Comparison of the Intubating Laryngeal Mask Airway with the Fiberoptic Intubation in Anticipated Difficult Airway Management

Background: The intubating laryngeal mask airway (ILMA; Fastrach (TM); Laryngeal Mask Company, Henley-on-Thames, UK) may provide an alternative technique to fiberoptic intubation (FIB) to facilitate the management of the anticipated difficult airway. The authors therefore compared the effectiveness of the ILMA with FIB in patients with anticipated difficult intubation.

Methods: One hundred patients, with at least one difficult intubation criteria (Mallampati class III or IV, thyromental distance < 65 mm, interincisor distance < 35 mm) were enrolled (FIB group, n = 49; ILMA group, n = 51) in this prospective randomized study. Anesthesia was induced with propofol and maintained with alfentanil and propofol after an efficient mask ventilation has been demonstrated. The success of the technique (within three attempts), the number of attempts, duration of the successful attempt, and adverse events (oxygen saturation < 90%, bleeding) were recorded.

Results: The rate of successful tracheal intubation with ILMA was 94% and comparable with FIB (92%). The number of attempts and the time to succeed were not significantly different between groups. In case of failure of the first technique, the alternative technique always succeeded. Failures in FIB group were related to oxygen desaturation (oxygen saturation < 90%) and bleeding, and to previous cervical radiotherapy in the ILMA group. Adverse events occurred significantly more frequently in FIB group than in ILMA group (18 vs. 0%, P < 0.05).     

Use of the intubating laryngeal mask airway: are muscle relaxants necessary?

BACKGROUND: The intubating laryngeal mask airway (ILMA) is designed to facilitate blind tracheal intubation. The effect of a muscle relaxant on the ability to perform tracheal intubation through the ILMA device has not been previously evaluated. This randomized, double-blind, placebo-controlled study was designed to evaluate rocuronium, 0.2 or 0.4 mg/kg administered intravenously, on the success rate and incidence of complications associated with ILMA-assisted tracheal intubation. METHODS: A total of 75 healthy patients were induced with propofol 2 mg/kg and fentanyl 1 microg/kg intravenously. After insertion of the ILMA device, patients were administered either saline, rocuronium 0.2 mg/kg, or rocuronium 0.4 mg/kg in a total volume of 5 ml. At 90 s after administration of the study drug, tracheal intubation was attempted using a disposable polyvinyl tube. If unsuccessful, a reusable silicone tube was tried. In addition to recording the time and number of attempts required to secure the airway, the incidence of complications during placement of the tracheal tube and removal of the ILMA were noted. RESULTS: Tracheal intubation was successful in 76-96% of the patients. The overall success rates and times required to secure the airway were similar in all three treatment groups. The high-dose rocuronium group experienced less patient movement (8 vs. 28 and 48%) and coughing (12 vs. 20 and 52%) than the low-dose rocuronium and saline groups, respectively. Use of rocuronium was also associated with a dose-related decrease in the requirement for supplemental bolus doses of propofol during intubation and removal of the ILMA device. CONCLUSIONS: Use of rocuronium did not significantly improve the success rate in performing tracheal intubation through the ILMA. However, it produced dose-related decreases in coughing and movement after tracheal intubation and reduced difficulties associated with removal of the ILMA device.     

Airway management using the intubating laryngeal mask airway for the morbidly obese patient

We studied the effectiveness of the intubating laryngeal mask airway (ILMA) in morbidly obese patients scheduled for bariatric surgery. We included 118 consecutive morbidly obese patients (body mass index, 45 +/- 5 kg/m(2)). After the induction of general anesthesia, the laryngeal view was classified by the first observer according to the method of Cormack and Lehane. The ILMA was then inserted, and the trachea was intubated through the ILMA by a second observer. The rate of successful tracheal intubation with ILMA was 96.3%. The success rate, the number of attempts, and the total duration of the procedure were not different among patients with low-grade (Cormack 1-2) and patients with high-grade (Cormack 3-4) laryngeal views. The time required for insertion of the ILMA was slightly longer in patients with high-grade laryngeal views. Failures of the technique were not explained by the experience of the practitioner or airway characteristics. No adverse effect related to the technique was reported. Results of this study suggest that using the ILMA provides an additional technique for airway management of morbidly obese patients. IMPLICATIONS: The intubating laryngeal mask airway (ILMA) provides an additional technique for airway management of morbidly obese patients. The best choice of the primary technique (laryngoscopy or ILMA) for tracheal intubation of an adult obese patient remains to be determined.     

Erste Erfahrungen mit der Intubationslarynxmaske

Objective: We report our initial experience with an improved model of the laryngeal mask airway, the intubating laryngeal mask airway (ILMA, commercial name Fastrach), which was designed by A.I.J. Brain to improve blind endotracheal intubation through a laryngeal mask. Methods: In the ILMA, a number of construction details were newly designed compared to a standard laryngeal mask airway (SLM): 1) the angle between the shaft and the mask plane is changed, and also the radius of the shaft, 2) the internal diameter of the shaft is increased to allow the passage of an 8.0 mm cuffed endotracheal tube, resulting in an outer diameter of 2.0 cm, 3) a stable rubber lip (epiglottic elevating bar) is incorporated instead of the gills to clear the epiglottis out of the lumen during the passage of the endotracheal tube, 4) the shaft is manufactured out of stainless steel covered by silicone with a handle attached for more precise guidance. We prospectively used the ILMA in 80 patients for blind intubation. 51 had normal anatomy (group I), 19 were difficult to intubate (Cormack grade 3–4; group II), 18 had a reduced mouth opening (≤2.5 cm awake; group III), 8 of them also were difficult to intubate. Results: Insertion of the ILMA and ventilation was possible in all patients but one with a mouth opening of 1.3 cm during anaesthesia. 4 patients with difficult intubation and one with normal anatomy could not be ventilated with a face mask but could be ventilated with the ILMA. Blind intubation was successful in 69 out of 80 patients (global success rate 87%; group I: 84%; II: 95%; III: 83%), in 38 during the first attempt (initial success rate 48%; group I: 45%; II: 63%; III: 44%), showing no difference for patients with normal anatomy, difficult intubation or reduced mouth opening. For 82 successful intubations, 157 intubation attempts were performed (success rate per attempt 52%; group I: 48%; II: 67%; III: 54%). Success rate per attempt decreased to 42%, if intubation was not successful during the first attempt (106 intubation attempts resulting in 44 successful intubations, including 31 intubation attempts for 11 failures; group I: 35%; II: 56%; III: 38%). Intubation through the ILMA was not possible in 11 patients (14%). Failures to intubate were caused by a reduced mouth opening in 1 patient, an unsuited endotracheal tube in 1 patient, a wrong size of the ILMA may have been the cause in 6 patients, in the remaining 3, lacking personal skill may have been responsible. Endotracheal tubes suited to be used with the ILMA are straight or preformed Woodbridge tubes, whereas standard plastic tubes are too stiff. Manouvres facilitating blind intubation though the ILMA were careful alignment of the ILMA with the handle, an up and down manouvre, rotation of the tube or head movements. Conclusion: The ILMA improved ventilation compared to a face mask and almost doubled the success rate of blind intubation compared to a SLM in our hands in a variety of intubation situations. The ILMA has the potential to be useful in difficult to intubate patients – except those with cervical pathology – or in emergency medicine. Handling can be trained during every day routine. Experienced judgement of definite endotracheal tube placement is mandatory.