The intubating laryngeal mask airway facilitates tracheal intubation in the lateral position

Although the difficulty of tracheal intubation in the lateral position has not been systematically evaluated, airway loss during surgery in a laterally positioned patient may have hazardous consequences. We explored whether the intubating laryngeal mask airway (ILMA) facilitates tracheal intubation in patients with normal airway anatomy, i.e., Mallampati grade or=5 cm, positioned in the lateral position. We evaluated whether this technique can be used as a rescue when the airway is lost during the middle of surgery in laterally positioned patients with respect to success rate and intubation time. Anesthesia was induced with propofol, fentanyl, and vecuronium in 50 patients undergoing spine surgery for lumbar disk herniation (Lateral) and 50 undergoing other surgical procedures (Supine). Patients having disk surgery (Lateral) were positioned on their right or left sides before induction of general anesthesia, and intubation was performed in that position. Patients in the control group (Supine) were anesthetized in supine position, and intubation was performed in that position. Intubation was performed blindly via an ILMA in both groups. The time required for intubation and number and types of adjusting maneuvers used were recorded. Data were compared by the Mann-Whitney U test, Fisher's exact test, chi(2) test, or unpaired Student's t-test, as appropriate. Data presented as mean (SD). Demographic and airway measures were similar in the two groups, except for mouth opening, which was slightly wider in patients in the lateral position: 5.1 (0.9) versus 4.6 (0.7) cm. The time required for intubation was similar in each group ( approximately 25 s), as was intubation success (96%). We conclude that blind intubation via an ILMA offers a frequent success rate and a clinically acceptable intubation time (<1 min) even in the lateral position. IMPLICATIONS: Blind intubation via the intubating laryngeal mask airway (ILMA) offers frequent success and a clinically acceptable intubation time even in patients in the lateral position.     

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.     

Awake tracheal intubation through the intubating laryngeal mask

PURPOSE: To report successful awake insertion of the intubating laryngeal mask (Fastrach) and subsequent tracheal intubation through it, in a patient with predicted difficult tracheal intubation, due to limited mouth opening, and difficult ventilation through a facemask, due to a large mass at the corner of the mouth. CLINICAL FEATURES: A 53-yr-old woman with a large post-gangrenous mass on the right cheek to the angle of the mouth was scheduled for its resection. The right side of her face was damaged by a bomb attack followed by cancrum oris 50 yr ago. The distance between the incisors during maximum mouth opening was 2 cm and that between the gums on the right side < 1 cm. After preoxygenation and 50 micrograms fentanyl and 30 mg propofol i.v., propofol was infused at 2 mg.kg-1.hr-1. Lidocaine, 8%, was sprayed on the oropharynx. A #4 intubating laryngeal mask was inserted with a little difficulty. A fibrescope was passed through a 7.5-mm ID RAE tracheal tube, and the combination was easily passed through the laryngeal mask into the trachea. General ansthesia was then induced. Finally, the intubating laryngeal mask was removed, while the RAE tube was being stabilized using an uncuffed 6.0-mm ID tracheal tube. CONCLUSION: Awake tracheal intubation through the intubating laryngeal mask is a useful technique in patients with limited mouth opening in whom ventilation via a facemask is expected to be difficult.     

Malposition of the epiglottis after tracheal intubation via the intubating laryngeal mask

The intubating laryngeal mask has been reported to be a successful method of tracheal intubation although advancement of the tracheal tube via the laryngeal inlet into the trachea cannot be seen. Damage to the larynx or other tissues may occur during blind passage of a tracheal tube. We report a case in which the tracheal tube, advanced blindly, tucked the epiglottis into the laryngeal inlet, resulting in oedema of the epiglottis. This case illustrates the potential for airway obstruction after extubation when using the intubating laryngeal mask as a blind intubation guide.      

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.     

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.     

右美托咪定联合插管型喉罩在困难气道插管中的应用

目的 评价右美托咪定诱导联合插管型喉罩或纤维支气管镜(FOB)在清醒保留呼吸情况下气管插管的效果.方法 择期手术全麻患者96例,ASAⅡ或Ⅲ级,术前气道评估Mallampati分级≥Ⅲ级,Cormack-Lehane分级≥Ⅲ级.随机均分为四组:A组静注右美托咪定1μg/kg(10min)+芬太尼2 μg/kg联合插管型喉罩插管;B组静注咪达唑仑0.03 mg/kg+芬太尼2μg/kg联合插管型喉罩插管;C组静注右美托咪定1 μg/kg(10min)+芬太尼2μg/kg经鼻FOB插管;D组静注咪达唑仑0.03mg/kg+芬太尼2μg/kg经鼻FOB插管.记录麻醉前(T0)、静脉推注右美托咪定或咪达唑仑完毕即刻(T1)、静脉推注芬太尼后(T2)、置入插管型喉罩或FOB到达会厌即刻(T3)、插入气管导管时(T4)、插入气管导管后1 min(T5)、插入气管导管后给予肌松药后3min(T6)时MAP、HR、SpO2、BIS,并记录插管成功率、心动过速、高血压、有无躁动、呛咳等插管反应,记录插管前心动过缓使用阿托品和插管后的心动过速使用艾司洛尔情况,术后随访患者对插管过程是否耐受.结果 与T0时比较,T2、T3时A、C组HR明显减慢,T3～T5时B、D组HR明显增快,T3～T5时B、D组和T4、T5时C组MAP明显升高(P＜0.05).诱导插管前阿托品使用率A、C组明显高于B、D组;插管后艾司洛尔使用率A、C组明显低于B、D组(P＜0.05);术后躁动发生率A、B、C组均明显低于D组(P＜0.05);对麻醉中插管的耐受、下次是否愿意使用同样的麻醉方法A组均明显高于B、C、D组(P＜0.05).结论 右美托咪定联合插管型喉罩在困难气道保留呼吸插管安全有效,而且可以减少心动过速、高血压及心肌缺血发生率,增强对气管插管的耐受.     

Light-guided tracheal intubation using a prototype illuminated flexible catheter through the intubating laryngeal mask.

We evaluated the efficacy of a newly developed prototype illuminated flexible catheter to facilitate tracheal intubation through the intubating laryngeal mask and compared this light-guided technique with the conventional blind tracheal intubation through the intubating laryngeal mask. The illuminated flexible catheter consists of a completely flexible thin plastic catheter, a bulb attached to its distal end, a 15-mm concentric adapter at its proximal end connected with a battery and a power switch. The device is placed into a silicone tracheal tube in such a way that the bulb protrudes from the distal end of the tracheal tube. One hundred adult patients, ASA I-III, scheduled to undergo propofol/fentanyl/atracurium anaesthesia for elective surgery were studied. All participants underwent a randomized double comparative cross over trial with respect to the tracheal intubation technique through the intubating laryngeal mask. The light guided tracheal intubation was performed as follows; the tracheal tube preloaded with the illuminated flexible catheter was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. Whenever resistance was felt during insertion, appropriate adjusting manoeuvres were performed. The intubating laryngeal mask was inserted successfully in all patients. The success rate for the blind and light-guided technique was 91% and 100%, respectively (P = 0.003). The mean (+/- SD) duration including appropriate intubating laryngeal mask placement and tracheal intubation, was significantly lower in the light-guided tracheal intubation technique, than with the blind tracheal intubation (31 +/- 8 s vs. 43 +/- 18 s; P < 0.0001). We conclude that the use of an illuminated flexible catheter carries advantages either in optimizing the intubating laryngeal mask position in the laryngopharynx or in achieving a quick and safe light-guided advancement from laryngopharynx into the trachea.     

Comparison of times to achieve tracheal intubation with three techniques using the laryngeal or intubating laryngeal mask airway

We compared the times to intubate the trachea using three techniques in 60 healthy patients with normal airways: (i) fibreoptic intubation with a 6.0-mm reinforced tracheal tube through a standard laryngeal mask airway (laryngeal mask-fibreoptic group); (ii) fibreoptic intubation with a dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-fibreoptic group); (iii) blind intubation with the dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-blind group). Mean (SD) total intubation times were significantly shorter in the intubating laryngeal mask-blind group (49 (20) s) than in either of the other two groups (intubating laryngeal mask-fibreoptic 74 (21) s; laryngeal mask-fibreoptic group 75 (36) s; p < 0.001). However, intubation at the first attempt was less successful with the intubating laryngeal mask-blind technique (15/20 (75%)) than in the other two groups (intubating laryngeal mask-fibreoptic 19/20 (95%) and laryngeal mask-fibreoptic 16/20 (80%)) although these differences were not statistically significant. We conclude that in this patient group, all three techniques yield acceptable results. If there is a choice of techniques available, the intubating laryngeal mask-blind technique would result in the shortest intubation time.     

Use of the intubating laryngeal mask for airway management and light-guided tracheal intubation in the lateral position

Sudden accidental loss of the airway during surgery is potentially hazardous especially when the patient is lying in any position which prevents easy intubation of the trachea. We describe two patients lying in the lateral position who required urgent airway management and endotracheal intubation. In both cases endotracheal intubation was achieved successfully using a light-guided technique--with a prototype illuminated flexible catheter--through an intubating laryngeal mask airway.     

The intubating laryngeal mask airway in failed fibreoptic intubation

PURPOSE: Prediction of difficult tracheal intubation is not always reliable and management with fibreoptic intubation is not always successful. We describe two cases in which blind intubation through the intubating laryngeal mask airway (ILMA FasTrach) succeeded after fibreoptic intubation failed. CLINICAL FEATURES: The first patient, a 50 yr old man, was scheduled for elective craniotomy for intracerebral tumour. Difficulty with intubation was not anticipated. Manual ventilation was easily performed following induction of general anesthesia, but direct laryngoscopy revealed only the tip of the epiglottis. Intubation attempts with a styletted 8.0 mm endotracheal tube and with the fibreoptic bronchoscope were unsuccessful. A #5 FasTrach was inserted through which a flexible armored cuffed 8.0 mm silicone tube passed into the trachea at the first attempt. The second patient, a 43 yr old man, presented with limited mouth opening, swelling of the right submandibular gland that extended into the retropharynx and tracheal deviation to the left. He was scheduled for urgent tracheostomy. Attempted awake fibreoptic orotracheal intubation under topical anesthesia showed gross swelling of the pharyngeal tissues and only fleeting views of the vocal cords. A #4 FasTrach was easily inserted, a clear airway obtained and a cuffed 8.0 mm silicone tube passed into the trachea at the first attempt. CONCLUSION: The FasTrach may facilitate blind tracheal intubation when fibreoptic intubation is unsuccessful.