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.     

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.     

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.     

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.     

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.     

Conventional tracheal tubes for intubation through the intubating laryngeal mask airway

The laryngeal mask airway (LMA)-Fastrach silicone wire-reinforced tracheal tube (FTST) was specially designed for tracheal intubation through the intubating LMA (ILMA). However, conventional tracheal tubes have been successfully used to accomplish tracheal intubation. We designed this study to evaluate the success rate of blind tracheal intubation through the ILMA by using the FTST, the Rusch polyvinyl chloride tube (PVCT), and the Rusch latex armored tube (LAT). One-hundred-fifty healthy adults of ASA physical status I and II who were undergoing elective surgery under general anesthesia were randomly allocated into three groups. FTST (n=50), prewarmed PVCT (n=50), and LAT (n=50) were used for tracheal intubation. Ease of tracheal intubation was assessed by the time taken, the number of attempts, and the number of maneuvers required for success. In addition, numbers of failed intubation attempts and times taken for ILMA removal were also recorded. After surgery, the incidence of trauma, sore throat, and hoarseness was noted. Significantly more frequent success in tracheal intubation was achieved with the PVCT and FTST (96%) compared with the LAT (82%) (P <0.05). Tracheal intubation on the first attempt was similar with the PVCT and FTST (86%) and was significantly more frequent than with the LAT (52%) (P <0.05). Esophageal placement was significantly more frequent with the LAT (29.7%) when compared with the PVCT and FTST (1.8% and 7.4%, respectively) (P <0.05). The authors conclude that a prewarmed PVCT can be used as successfully as the FTST for blind tracheal intubation through the ILMA, whereas the LAT is associated with more frequent failure and esophageal intubation.     

A comparison of two techniques for inserting the Airtraq laryngoscope in morbidly obese patients

We postulated that video-controlled tracheal intubation with the Airtraq laryngoscope using the reverse manoeuvre instead of the standard technique of insertion could facilitate the airway management of morbidly obese patients. For the reverse manoeuvre the laryngoscope is inserted 180 degrees opposite to that recommended, and once in place rotated into the conventional pharyngeal position. Eighty (40 lean and 40 morbidly obese) ASA I-III adult patients were randomly allocated to four equal groups to compare the standard technique to the reverse manoeuvre for inserting the Airtraq laryngoscope. Video-controlled and clinical tracheal intubation characteristics were recorded. The reverse manoeuvre did not influence tracheal intubation characteristics in the group of lean patients. In the group of morbidly obese patients, the standard technique of insertion was not satisfactory in 20% of cases and the reverse manoeuvre facilitated, speeded and secured tracheal intubation.     

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).     

Awake videolaryngoscopy-assisted tracheal intubation of the morbidly obese

Awake videolaryngoscopy may be useful for the tracheal intubation of the morbidly obese. This prospective, observational study enrolled 50 patients undergoing bariatric surgery. After sedation and topical anaesthesia of the airway, awake tracheal intubation was attempted, assisted by videolaryngoscopy, and terminated if there was severe gagging, coughing, or inadequate laryngeal view. After three attempts the procedure was considered a failure. Twenty-seven intubations were successful on the first attempt, fifteen on the second, six on the third and two were not successful, giving a success rate of 96% (95% CI 86-100%). In one failure, inserting the tracheal tube caused severe gagging in spite of an adequate view of the larynx, and the trachea was intubated with the videolaryngoscope after induction of anaesthesia. The second failure was due to gagging, with subsequent tracheal intubation successful using fibreoptic bronchoscopy. When managing the morbidly obese airway, awake tracheal intubation using videolaryngoscopy may be considered.     

Flexible lightwand-guided tracheal intubation with the intubating laryngeal mask Fastrach in adults after unpredicted failed laryngoscope-guided tracheal intubation

BACKGROUND: The authors determined the efficacy of using the intubating laryngeal mask airway Fastrach (ILM) as a ventilatory device and aid to flexible lightwand-guided tracheal intubation in patients with unpredicted failed laryngoscope-guided tracheal intubation when managed by experienced anesthetists. METHODS: During a 27-month period, 16 experienced anesthetists agreed to use the ILM as an airway device and airway intubator in patients (aged > 18 yr) with predicted normal airways who were subsequently found to be difficult to intubate (three failed attempts at laryngoscopy). Intubation via the ILM was performed with a flexible lightwand. The number of attempts at ILM placement, the number of adjusting maneuvers, the number of attempts at tracheal intubation via the ILM,and any episodes of hypoxia (oxygen saturation < 90%) were recorded. RESULTS: Forty-four of 11,621 patients (0.4%) met the inclusion criteria. ILM insertion and ventilation was successful at the first attempt in 40 of 44 patients (91%) and at the second attempt in 4 of 44 (9%). Flexible lightwand-guided tracheal intubation via the ILM was successful in 38 of 44 patients (86%) at the first attempt, 3 of 44 (7%) at the second attempt, 2 of 44 (5%) at the third to fifth attempts, and failed in 1 of 44 (2%). The median number of adjusting maneuvers before successful intubation was 1 (range, 0-4). Hypoxia occurred in 5 patients before ILM insertion (range, 52-82%), but none after ILM insertion. No patient developed hypoxia during or after intubation via the ILM. CONCLUSION: The ILM is an effective ventilatory device and aid to flexible lightwand-guided tracheal intubation in adult patients with predicted normal airways in whom laryngoscope-guided tracheal intubation subsequently fails when managed by experienced anesthetists.     

Novices ventilate and intubate quicker and safer via intubating laryngeal mask than by conventional bag-mask ventilation and laryngoscopy

BACKGROUND: Because airway management plays a key role in emergency medical care, methods other than laryngoscopic tracheal intubation (LG-TI) are being sought for inadequately experienced personnel. This study compares success rates for ventilation and intubation via the intubating laryngeal mask (ILMA-V/ILMA-TI) with those via bag-mask ventilation and laryngoscopic intubation (BM-V/LG-TI). METHODS: In a prospective, randomized, crossover study, 30 final-year medical students, all with no experience in airway management, were requested to manage anesthetized patients who seemed normal on routine airway examination. Each participant was asked to intubate a total of six patients, three with each technique, in a randomly assigned order. A task not completed after two 60-s attempts was recorded as a failure, and the technique was switched. RESULTS: The success rate with ILMA-V was significantly higher (97.8% vs. 85.6%; P < 0.05), and ventilation was established more rapidly with ILMA-V (35.6 +/- 8.0 vs. 44.3 +/- 10.8 s; P < 0.01). Intubation was successful more often with ILMA-TI (92.2% vs. 40.0%; P < 0.01). The time needed to achieve tracheal intubation was significantly shorter with ILMA-TI (45.7 +/- 14.8 vs. 89.1 +/- 23.3 s; P < 0.01). After failed LG-TI, ILMA-V was successful in all patients, and ILMA-TI was successful in 28 of 33 patients. Conversely, after failed ILMA-TI, BM-V was possible in all patients, and LG-TI was possible in 1 of 5 patients. CONCLUSION: Medical students were more successful with ILMA-V/ILMA-TI than with BM-V/LG-TI. ILMA-TI can be successfully used when LG-TI has failed, but not vice versa. These results suggest that training programs should extend the ILMA to conventional airway management techniques for paramedical and medical personnel with little experience in airway management.     

Unanticipated difficult airway in anesthetized patients: prospective validation of a management algorithm

BACKGROUND: Management strategies conceived to improve patient safety in anesthesia have rarely been assessed prospectively. The authors undertook a prospective evaluation of a predefined algorithm for unanticipated difficult airway management. METHODS: After a 2-month period of training in airway management, 41 anesthesiologists were asked to follow a predefined algorithm for management in the case of an unanticipated difficult airway. Two different scenarios were distinguished: "cannot intubate" and "cannot ventilate." The gum elastic bougie and the Intubating Laryngeal Mask Airway (ILMA) were proposed as the first and second steps in the case of impossible laryngoscope-assisted tracheal intubation, respectively. In the case of impossible ventilation or difficult ventilation, the IMLA was recommended, followed by percutaneous transtracheal jet ventilation. The patient's details, adherence rate to the algorithm, efficacy, and complications of airway management processes were recorded. RESULTS: Impossible ventilation never occurred during the 18-month study. One hundred cases of unexpected difficult airway were recorded (0.9%) among 11,257 intubations. Deviation from the algorithm was recorded in three cases, and two patients were wakened before any alternative intubation technique attempt. All remaining patients were successfully ventilated with either the facemask (89 of 95) or the ILMA (6 of 95). Six difficult-ventilation patients required the ILMA before completion of the first intubation step. Eighty patients were intubated with the gum elastic bougie, and 13 required a blind intubation through the ILMA. Two patients ventilated with the ILMA were never intubated. CONCLUSION: When applied in accordance with a predefined algorithm, the gum elastic bougie and the ILMA are effective to solve most problems occurring during unexpected difficult airway management.     

Tracheal intubation in morbidly obese patients: a comparison of the Intubating Laryngeal Mask Airway™ and Laryngeal Mask Airway CTrach™

The aim of this study was to evaluate the efficacy of the Intubating Laryngeal Mask Airway? (ILMA) and Laryngeal Mask Airway CTrach? (LMA CTrach) in facilitating tracheal intubation in morbidly obese patients. Eighty patients (body mass index > 40kg.m^?2) were randomly allocated to the ILMA or the LMA CTrach. The median (IQR [range]) total time taken for tracheal intubation was shorter with the ILMA than with the LMA CTrach (78 (63–105 [40–265]) s vs 128 (98–221 [60–423]) s, respectively; p < 0.001). Significantly more manoeuvres were applied for the satisfactory ventilation and viewing of the glottis with the LMA CTrach (25% vs 55% with the ILMA; p = 0.006). During the postoperative period, there was more sore throat with the LMA CTrach (p < 0.02). We conclude that the ILMA results in shorter intubation times with fewer manoeuvres and sore throat compared with the LMA CTrach in the morbidly obese.     

The LMA CTrach™ in morbidly obese and lean patients undergoing gynecological procedures: a comparative study

Purpose

The tracheas of obese patients may be more difficult to intubate than those of normal-weight patients. The aim of this study was to compare the airway management quality in morbidly obese and lean patients with use of the LMA CTrach.

Methods

After Ethics Committee approval, 60 adult patients (30 morbidly obese patients with body mass index >40 kg/m² and 30 lean patients with body mass index <30 kg/m²) scheduled to undergo gynecological surgery were enrolled in this prospective study. The induction of anesthesia was standardized using propofol, fentanyl, and rocuronium. Ventilation and intubation success rates, time taken to achieve successful ventilation, and intubation through the CTrach and airway complications were recorded.

Results

The CTrach was successfully inserted and adequate ventilation through the CTrach was achieved in 59 patients (98%). Only 1 patient in the lean group was not able to ventilate through the CTrach. We were successful in endotracheal intubation, either under vision or blind, in 56 patients (93%). We were able to view the larynx in 51 patients (85%). Total intubation time was significantly longer in morbidly obese patients, 69 (311) s, than in lean patients, 33 (107) s [median (range)] (P < 0.001).

Conclusions

We concluded that the time to intubate the trachea in obese patients was significantly longer than in lean patients when the LMA CTrach was used.     

Unanticipated Difficult Airway in Anesthetized Patients: Prospective Validation of a Management Algorithm

Background: Management strategies conceived to improve patient safety in anesthesia have rarely been assessed prospectively. The authors undertook a prospective evaluation of a predefined algorithm for unanticipated difficult airway management.

Methods: After a 2-month period of training in airway management, 41 anesthesiologists were asked to follow a predefined algorithm for management in the case of an unanticipated difficult airway. Two different scenarios were distinguished: "cannot intubate" and "cannot ventilate." The gum elastic bougie and the Intubating Laryngeal Mask Airway(TM) (ILMA(TM)) were proposed as the first and second steps in the case of impossible laryngoscope-assisted tracheal intubation, respectively. In the case of impossible ventilation or difficult ventilation, the IMLA was recommended, followed by percutaneous transtracheal jet ventilation. The patient's details, adherence rate to the algorithm, efficacy, and complications of airway management processes were recorded.

Results: Impossible ventilation never occurred during the 18-month study. One hundred cases of unexpected difficult airway were recorded (0.9%) among 11,257 intubations. Deviation from the algorithm was recorded in three cases, and two patients were wakened before any alternative intubation technique attempt. All remaining patients were successfully ventilated with either the facemask (89 of 95) or the ILMA(TM) (6 of 95). Six difficult-ventilation patients required the ILMA(TM) before completion of the first intubation step. Eighty patients were intubated with the gum elastic bougie, and 13 required a blind intubation through the ILMA(TM). Two patients ventilated with the ILMA(TM) were never intubated.     

The intubating laryngeal mask airway compared with direct laryngoscopy

We have compared the ability of naive intubators to intubate the trachea using a laryngoscope and an intubating laryngeal mask airway (ILMA) after receiving basic training, in a randomized, prospective, crossover study in 60 patients. Ventilation of the lungs via the ILMA was also compared with ventilation with a face mask. There was no significant difference in successful intubation between the techniques (38 of 89 with the ILMA and 33 of 93 with direct laryngoscopy; ns). In patients in whom participants failed in their intubation attempts with the ILMA, investigators achieved success in 89% (16 of 18). Satisfactory ventilation was more common with the ILMA (50 of 51) than with the face mask (43 of 60) (P = 0.0001). A total of 98% (89 of 91) of ILMA were inserted successfully, with a mean insertion time of 19.6 s, and 78% (69/89) of these insertions were achieved in less than 26 s. The ILMA may be useful for emergency oxygenation and ventilation, but these results do not support its use for intubation by those not trained in advanced airway management and ILMA use.      

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.     

The Laryngeal Mask Airway ProSeal(TM) as a temporary ventilatory device in grossly and morbidly obese patients before laryngoscope-guided tracheal intubation

We determined the efficacy of the laryngeal mask airway ProSeal(TM) (PLMA) as a temporary ventilatory device in morbidly obese patients before laryngoscope-guided tracheal intubation. Sixty patients (body mass index 35--60 kg/m(2)) scheduled for elective surgery, who preferred airway management under general anesthesia, were studied. The induction of anesthesia was with midazolam/fentanyl/propofol and maintenance was with sevoflurane 1%--3% in oxygen 100%. The PLMA was inserted and an effective airway established. Rocuronium was given IV for paralysis. Oropharyngeal leak pressure, ease of gastric tube placement, residual gastric volume, fiberoptic position of the airway/drainage tube, and ease of ventilation at a tidal volume of 8 mL/kg was determined. The PLMA was then removed and laryngoscope-guided tracheal intubation attempted. The number of insertion/intubation attempts (maximum two each) and time taken to establish an effective airway with each device were recorded. An effective airway was obtained at the first insertion attempt in 90% of patients (54/60) and at the second attempt in 10% (6/60). The time taken to provide an effective airway was 15 plus minus 7 s (7--42 s). Oropharyngeal leak pressure was 32 plus minus 8 cm H(2)O (12--40 cm H(2)O). The residual gastric volume was 36 plus minus 46 mL (0--240 mL). Positive pressure ventilation without air leaks was possible in 95% of patients (57/60). The vocal cords were seen from the airway tube in 75% of patients (45/60), but the esophagus was not seen. The fiberoptic view from the drainage tube revealed mucosa in 93% of patients (56/60) and an open upper esophageal sphincter in 7% (4/60). Tracheal intubation was successful at the first attempt in 90% of patients (54/60), at the second attempt in 7% (4/60), and failed in 3% (2/60). In these latter two patients, the PLMA was reinserted and surgery performed uneventfully with the PLMA. The time taken to tracheally intubate the patient was 13 plus minus 10 s (8--51 s). There were no episodes of hypoxia (SpO(2) <90%) or other adverse events. There were no differences in insertion success rate, or the time to successful insertion between the PLMA and laryngoscope-guided intubation. We conclude that the PLMA is an effective temporary ventilatory device in grossly or morbidly obese patients before laryngoscope-guided tracheal intubation. IMPLICATIONS: The laryngeal mask airway ProSeal(TM) is an effective temporary ventilatory device in grossly and morbidly obese patients before laryngoscope-guided tracheal intubation.     

Tracheal intubation of morbidly obese patients: a randomized trial comparing performance of Macintosh and Airtraq laryngoscopes

BACKGROUND: The Airtraq laryngoscope is designed to allow visualization of the glottis without alignment of the oral, pharyngeal, and laryngeal axes. We hypothesized that this new airway device would facilitate tracheal intubation of morbidly obese patients. We compared tracheal intubation performance of standard Macintosh laryngoscope with the Airtraq laryngoscope in morbidly obese patients. METHODS: One hundred and six consecutive ASA I-III morbidly obese patients undergoing surgery were randomized to intubation with the Macintosh laryngoscope or the Airtraq laryngoscope. Induction of anaesthesia was standardized. If tracheal intubation failed within 120 s with the Macintosh or Airtraq , laryngoscopes were switched. Success rate, SpO2, duration of tracheal intubation, and quality of airway management were evaluated and compared between the groups. RESULTS: Preoperative characteristics of the patients were similar in both groups. In the Airtraq group, tracheal intubation was successfully carried out in all patients within 120 s. In the Macintosh laryngoscope group, six patients required intubation with the Airtraq laryngoscope. The mean (SD) time taken for tracheal intubation was 24 (16) and 56 (23) s, respectively, with the Airtraq and Macintosh laryngoscopes, (P<0.001). SpO2 was better maintained in the Airtraq group than in the Macintosh laryngoscope group with one and nine patients, respectively, demonstrating drops of SpO2 to 92% or less (P<0.05). CONCLUSIONS: In this study, the Airtraq laryngoscope shortened the duration of tracheal intubation and prevented reductions in arterial oxygen saturation in morbidly obese patients.     

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.