Improved esophageal patency when inserting the ProSeal™ laryngeal mask airway with an Eschmann™ tracheal tube introducer

Purpose

We hypothesized that a more accurate alignment of the tip of the drain tube with the upper esophageal opening would be achieved in adult patients, as confirmed by fibreoptic bronchoscopy, by placing the ProSeal? laryngeal mask airway (PLMA) by means of guiding it over an Eschmann? tracheal tube introducer, commonly know as a gum elastic bougie (GEB), that was previously inserted into the esophagus, rather than by placing the PLMA with a curved metal introducer (IT).

Methods

Seventy-five adult elective surgery patients, whose airway management involved a PLMA, were randomly allocated to either the GEB- or IT-guided techniques. After inserting the PLMA, alignment of the tip of the drain tube relative to the esophageal opening was verified by a fibrescope introduced through the drain tube. Placing the fibrescope through the PLMA identified the glottic structures. The primary endpoint indicating the proper alignment of the tip of the drain tube of the PLMA with the upper esophageal opening was the ability to pass the fibrescope into the esophagus through the drain tube by a distance >35 cm without obstruction and the ability to simultaneously visualize the esophageal mucosa.

Results

The overall success rates of PLMA insertion were similar in the GEB and IT groups. However, the mean airway insertion times were longer with the GEB than with the IT-PLMA. The GEB group achieved proper alignment of the drain tube and the upper esophageal opening more frequently than the IT group (97% confidence interval (CI₉₅) 91.5–100% vs 81% CI₉₅ 68.5–93.5% of subjects, respectively; P = 0.027). When the GEB was used to place the PLMA, the patients’ vocal cords were visualized more frequently than when the IT technique was used (100% vs 73% CI₉₅ 58.9–87.1% of subjects, respectively; P = 0.003).

Conclusion

Fibreoptic bronchoscopy confirmed that GEB is superior to the IT technique in ensuring precise alignment of the tip of the drain tube of the PLMA with the upper esophageal opening. Accurate positioning may better preserve gastroesophageal drainage function of the PLMA.     

Comparison of blind tracheal intubation through the intubating laryngeal mask airway (LMA Fastrach™) and the Air-Q™

This study assessed two disposable devices, the LMA Fastrach^TM and the newly developed supraglottic airway device, the Air‐Q^TM, as a conduit for tracheal intubation in 154 healthy adults undergoing elective surgery. Using a non‐inferiority approach, the primary outcome measure was successful tracheal intubation within two blind insertion attempts. Successful blind intubation after two attempts was achieved in 75/76 (99%) of the patients in the LMA Fastrach group vs 60/78 (77%) in the Air‐Q group (95% CI for the difference 12–32%, p < 0.0001). Fibreoptic intubation was used to assist the third attempt. The rate of successful intubation after three attempts was 100% in the LMA Fastrach group and 95% in Air‐Q group. The single‐use LMA Fastrach appears superior compared with the Air‐Q, as a conduit to facilitate blind tracheal intubation.     

Fibreoptic-guided tracheal intubation through i-gel® and LMA® ProtectorTM supraglottic airway devices - a randomised comparison

Fibreoptic-guided tracheal intubation using a supraglottic airway device as a conduit is a technique that can be used in anticipated and unanticipated difficult airway management. Although the i-gel^® supraglottic airway device has been examined for this purpose, the LMA^® Protector^TM, a recently introduced second-generation supraglottic airway device, has not been evaluated for this use in clinical trials. This prospective, randomised clinical trial compared fibreoptic-guided tracheal intubation via i-gel and LMA Protector supraglottic airway devices in two UK hospitals. Patients who were ASA physical status 1 or 2 and undergoing elective surgery requiring tracheal intubation were recruited to the study. A block randomisation list was generated for each study site. The primary outcome measure was time to successful tracheal intubation and secondary outcomes were tracheal intubation success rate, glottic view through flexible fibrescope, ease of tracheal intubation using operator visual analogue score, supraglottic airway device insertion time and insertion success rate. Ninety patients were randomly allocated to each device, and final data analysis was carried out for 92 patients in the i-gel group and 86 patients in the LMA Protector group. Mean (SD) tracheal intubation time in the i-gel and LMA Protector groups were 54.3 (13.8) s and 52.0 (13.0) s, respectively (p = 0.240). There were no significant differences in tracheal intubation success rate, glottic view and ease of tracheal intubation between the two groups. This study demonstrates that the LMA Protector supraglottic airway device is comparable to the i-gel supraglottic airway device as a conduit for fibreoptic-guided tracheal intubation.     

Evaluation of air-Q™ intubating laryngeal airway as a conduit for tracheal intubation in infants--a pilot study

Background: Air‐Q^TM intubating laryngeal airway (ILA) has been used successfully as a conduit for tracheal intubation in pediatric difficult airway. However, its use as an airway device and conduit for intubation in infants is not yet evaluated. Aims: The primary objective was to evaluate ILA as a conduit for tracheal intubation in infants, and secondary objectives were to evaluate ILA in terms of ease of insertion and ventilation, oropharyngeal leak pressure (OLP), glottic view, and complications. Methods: Twenty infants with normal airway were included. After induction of general anesthesia and neuromuscular blockade, ILA (size 1.0/1.5) was inserted. Fiberoptic bronchoscope (FOB)–guided intubation and removal of ILA with the stabilizing stylet was attempted. Results: The mean age and weight of the infants were 7.5 ± 2.3 months and 7.3 ± 1.8 kg. The ILA sizes 1.0 and 1.5 were inserted in 10 infants each according to the weight of the infants. The mean OLP was 18.5 ± 1.8 cm H₂O, and mean time for insertion of ILA was 13.3 ± 3.9 s. Glottic view was grade I in 6, grade II in 1, grade III in 4, and grade IV in nine infants. Tracheal intubation was successful in 19/20 infants. The mean endotracheal tube (ETT) insertion time and mean total time (ILA insertion to the confirmation of ETT placement) were 95.6 ± 32.3 s and 306.42 ± 120.2 s respectively. Conclusion: The ILA is a safe and easy‐to‐use supraglottic airway device for intubation with FOB in infants with normal airway. Insertion and removal of ILA are easy with satisfactory oropharyngeal seal and ventilation.     

Tips and tricks to increase the success rate of blind tracheal intubation through the Air-Q™ versus the intubating laryngeal mask airway Fastrach™

BackgroundThe Air-Q intubating laryngeal airway is a new supraglottic airway device which overcomes some of the limitations inherent to the intubating laryngeal mask airway (ILMA Fastrach^™) for tracheal intubation. Previous studies showed lower success rate of the Air-Q^™ versus ILMA Fastrach^™. This study was conducted to illustrate new maneuvers for increasing the success rate of Air-Q^™ versus ILMA Fastrach^™ and compare between both devices.MethodsOne-hundred and seventy adult patients, ASA I or II, aged >16 years old undergoing elective surgery under general anesthesia were divided randomly into 2 equal groups (85 each). Group A: using Air-Q ILA size 3.5 or size 4.5 Group B: using ILMA size 4 or size 5 according to the manufacturer’s recommendations for body weight in both groups. The time and the total success rate of blind intubation through them in 2 attempts only were recorded. In Group A, extension of the head with cricoid pressure was applied. The hemodynamic response to devices insertion and the complications related to both devices were compared.ResultsIn Group A, the total success rate in 2 attempts was 94.12%, while in Group B, it was 96.47%. However, this difference was not statistically significant. The first attempt success rate was 81.18% in Group A, while it was 82.35% in Group B. The total time to intubate the hemodynamic response to device insertion and the incidence of complications (sore throat, trauma and hoarseness of voice) showed no statistically significant difference between both groups.ConclusionThis study showed that extension of the head with cricoid pressure greatly increases the success rate of blind intubation through the Air-Q to 94.12% versus the ILMA Fastrach 96.47% with no statistically significant difference between both devices.     

Is fiberoptic bronchoscope a good intubating choice in anesthetized patients with anticipated difficult intubation?

Background

Fiberoptic bronchoscope may be a good intubating tool in anesthetized patients with predicted difficult intubation. We conducted this prospective randomized study to compare intubation using FOB and direct laryngoscopy (DL) after induction of general anesthesia.

Methods

One hundred adult patients (50 patients in DL group, and 50 patients in the FOB group) with at least one difficult intubation criteria were enrolled in the study. Both FOB and DL were attempted after induction of anesthesia and verification of mask ventilation. Incidence of failed intubation (more than two attempts), successful intubation, and total induction times were recorded. Adverse events during intubation process were documented. Postoperatively, patients fulfilled a questionnaire to assess sequale of intubation.

Results

The overall success rate for tracheal intubation was higher in the FOB (100% Vs 86%; p < 0.05). Successful primary and secondary intubation attempts were higher in the FOB group (94% Vs 64%; p < 0.05 and 100% Vs 61%; p < 0.05, respectively). All patients who failed laryngoscopic intubation were successfully intubated using the fiberoscope. Induction and successful intubation times were longer in the laryngoscopy group (128 + 93.7 s Vs 79.9 + 27.2 s p < 0.05 and 67.5 + 88.6 s Vs 19.2 + 27 s p < 0.05, respectively). Adverse effects including tissue trauma and dental injury were greater in the DL group. Postoperative patient’s dissatisfaction, sore throat, and hoarseness were statistically higher in the DL group.

Conclusion

We concluded that, FOB is an effective and safe intubating tool in anesthetized patients with anticipated difficult intubation.     

Effectiveness and safety of the Levitan FPS Scope? for tracheal intubation under general anesthesia with a simulated difficult airway

Purpose

Studies show that the Levitan FPS (first pass success) Scope? (LFS) is analogous to a bougie in simulated difficult airways with comparable tracheal intubation success rates. In this study, the efficacy and safety of tracheal intubation with the LFS was compared with that of the Macintosh laryngoscope utilizing manual in-line stabilization (MILS) to simulate difficult airways.

Methods

Ninety-four subjects successfully completed the trial. Manual in-line stabilization of the cervical spine was applied and the initial laryngoscopy was performed using either the Macintosh or the LFS in conjunction with the Macintosh. Following the initial grading, a second laryngoscopy was repeated using the second randomized technique. Cormack-Lehane grades, percentage of glottic opening (POGO) scores, time to intubate, number of intubation attempts, and the use of alternate techniques were recorded. The anesthesiologist rated the subjective difficulty in using each technique with a numeric rating scale and a visual rating scale.

Results

There was no significant difference in the primary outcome ??good laryngoscopic views?? (Cormack-Lehane grade 1 and 2) compared with ??poor laryngoscopic views?? (Cormack-Lehane grade 3 and 4) between the LFS and the Macintosh. There were higher POGO scores with the LFS compared with the Macintosh (80% vs 20%, respectively; P?<?0.0001), but this did not translate to easier intubations, as documented by the need for an alternate intubation technique or time to intubate (< 30 and < 60?sec, respectively). The incidence of mucosal trauma, sore throat, and hemodynamic responses did not differ significantly between the two techniques.

Conclusion

The LFS in conjunction with the Macintosh laryngoscope does not improve the efficacy or safety of tracheal intubation in a simulated difficult airway.     

The difficult airway with recommendations for management – Part 1 – Difficult tracheal intubation encountered in an unconscious/induced patient

Background

Previously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered.

Methods

Nineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.

Conclusions

The clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.