Reflux during positive pressure ventilation via the laryngeal mask airway?

Comparison of the i-gel™ and the Laryngeal Mask Airway Classic™ in terms of clinical performance

PURPOSE

The i-gel™ is one of the second generation supraglottic airway devices. Our study was designed to compare the i-gel and the Laryngeal Mask Airway Classic™ with respect to the clinical performance.

METHODS

We compared the performance of the i-gel with that of the Laryngeal Mask Airway Classic in 120 patients undergoing urologic surgery during general anesthesia without muscle relaxant with respect to the number of attempts for successful insertion, insertion time, peak airway pressure, incidence of regurgitation, fiberoptic glottic view and postoperative complications. Second generation supraglottic airway devices were inserted by the same anesthesiologist, experienced in use of both devices (>200 uses and first time failure rate <5%). Methylene blue method was used to detect gastric regurgitation.

RESULTS

There was no statistical difference between the two groups regarding the success of insertion of second generation supraglottic airway device (p=0.951). The laryngeal mask insertion time for the i-gel group was significantly shorter than that for the Laryngeal Mask Airway Classic group (11.6±2.4s versus 13.1±1.8s [p=0.001]). The fiberoptic glottic view scores for the i-gel group was significantly better than that for the ones for the Laryngeal Mask Airway Classic group (p=0.001). On fiberoptic view, there was no sign of methylene blue dye at any time point in either group. In addition, there was no difference between the groups in patient response regarding the presence of a sore throat when questioned 24h after the procedure (p=0.752).

CONCLUSION

Both devices had good performance with low postoperative complications and without occurrence of regurgitation. The i-gel provided a shorter insertion time and a better fiberoptic view than the Laryngeal Mask Airway Classic.

A comparison of the i-gel with the LMA-Unique in non-paralysed anaesthetised adult patients

SUMMARY

This study assessed two disposable devices; the newly developed supraglottic airway device i-gel and the LMA-Unique in routine clinical practice. Eighty patients (ASA 1-3) undergoing minor routine gynaecologic surgery were randomly allocated to have an i-gel (n = 40) or LMA-Unique (n = 40) inserted. Oxygen saturation, end-tidal carbon dioxide, tidal volume and peak airway pressure were recorded, as well as time of insertion, airway leak pressure, postoperative sore-throat, dysphonia and dysphagia for each device. Time of insertion was comparable with the i-gel and LMA-Unique. There was no failure in the i-gel group and one failure in the LMA-Unique group. Ventilation and oxygenation were similar between devices. Mean airway pressure was comparable with both devices, whereas airway leak pressure was significantly higher (p < 0.0001) in the i-gel group (mean 29 cmH(2)O, range 24-40) compared with the LMA-Unique group (mean 18 cmH(2)O, range 6-30). Fibreoptic score of the position of the devices was significantly better in the i-gel group. Post-operative sore-throat and dysphagia were comparable with both devices. Both devices appeared to be simple alternatives to secure the airway. Significantly higher airway leak pressure suggests that the i-gel may be advantageous in this respect.

Intubation laryngeal mask: atraumatic diagnostic tool in suspension laryngoscopy

CONCLUSION

The new technique of ILM-guided vocal cord biopsy and APC is safe, cost-effective and non-invasive. It provides excellent airway control, adequate exposure of the vocal cords and effective treatment of laryngeal bleeding.

OBJECTIVE

Suspension microlaryngoscopy is a standard diagnostic procedure for vocal cord biopsy. In experienced hands failure of the procedure is extremely rare and may indicate a need for more invasive techniques. The aim of this study was to present a new technique of laryngoscopy/vocal cord biopsy and to review the relevant literature.

MATERIAL AND METHODS

After induction of general anesthesia and preoxygenation an intubation laryngeal mask (ILM) was inserted. A flexible bronchoscope was passed through the ILM and an anterior lesion was identified at the vocal cord. Biopsies were taken with forceps inserted through the instrument's working channel. The procedure was performed using video-endoscopic guidance. Bleeding from the wound surface was adequately treated with argon-plasma coagulation (APC).

RESULTS

Identification of the vocal cords was readily accomplished using the ILM. Only four literature reports matched our search criteria; all used the standard laryngeal mask or other instruments such as a laser or did not use the procedure for definitive therapy.

Learning to exchange an endotracheal tube for a laryngeal mask prior to emergence

PURPOSE

To present a stepwise training method, first critiquing laryngeal mask (LM) insertion difficulty and malpositioning, then learning how to exchange an endotracheal tube (ETT) for a LM during emergence from anesthesia.

METHODS

"Learning phase:" sixty adults were enrolled in a preliminary study in which ETT / LM exchange was not performed - only LM insertion difficulty and malpositioning in the presence of an oral ETT were evaluated. After induction of anesthesia and oral intubation, a classic LM size 4 was inserted using the standard recommended technique. Number of insertion attempts and fibreoptically determined malpositions were recorded. "ETT / LM exchange phase:" we performed airway exchange in 50 patients selected from our individual practices.

RESULTS

"Learning phase:" the LM was satisfactorily positioned, on first attempt, in 95% of cases. With multiple insertion attempts it was possible to place the LM in all 60 intubated patients. Unsuccessful initial placement of the LM was always due to insufficient insertion depth (5%). When fully inserted into the hypopharynx, the epiglottis could be viewed fibreoptically in 13% of cases. "ETT / LM exchange phase:" the LM was inserted successfully in all 50 patients on first attempt. No complications occurred during any exchange.

CONCLUSION

We found it is easy to learn how to insert a LM in the presence of an oral ETT. The most serious malposition, occurring in 5% of first attempts, was insufficient insertion depth. The only other malposition we encountered, fibreoptic visualization of the epiglottis, is not likely to result in complete airway obstruction following endotracheal extubation under anesthesia.

The laryngeal mask airway: a new technique for fiberoptic guided vocal cord biopsy

STUDY OBJECTIVE

To describe a new technique for vocal cord biopsy involving placement of a laryngeal mask airway (LMA) during general anesthesia and fiberoptic guided biopsy. To report our early experience with this technique.

DESIGN

Descriptive study.

SETTING

Teaching hospital.

PATIENTS

10 patients undergoing vocal cord biopsy for minor laryngeal pathology and with no evidence of infraglottic airway obstruction.

INTERVENTIONS

Patients were premedicated 1 hour preoperatively with pethidine 1 mg/kg and atropine 0.01 mg/kg. Following preoxygenation, anesthesia was induced with propofol 2.5 mg/kg and fentanyl 1 mg/kg. Once airway control was established with a facemask, vecuronium 0.1 mg was given and anesthesia established with oxygen (O2) and nitrous oxide mixture and isoflurane 1% to 2%. Gentle direct laryngoscopy was then performed to inspect the pharyngeal structures and the LMA was then inserted in the standard manner by highly experienced LMA users. A fiberoptic scope was passed via a self-sealing mount down the shaft of the LMA to the level of the vocal cords. The vocal cords were then sprayed with local anesthetic and the biopsy taken.

MEASUREMENTS AND MAIN RESULTS

The age and weight range were 29 to 57 years and 65 to 85 kg, respectively. All patients were smokers or recent ex-smokers. LMA insertion was readily achieved in all patients, and an excellent view of the vocal cords was obtained. There were no problems with ventilation or obtaining tissue samples, and O2 saturation remained greater than 95% throughout the perioperative period. Tissue samples were adequate in all patients. Hypertension and other adverse cardiac events did not occur during the procedure, which lasted 10 to 20 minutes. There were no problems during emergence from anesthesia, and all patients were discharged home on the same day.

CONCLUSIONS

The technique has potential advantages over suspension microlaryngoscopy in that it is relatively noninvasive, it allows good airway control with adequate views of the vocal cords, and it facilitates a smooth recovery.