Combined introducer for reinforced laryngeal mask airway

[Flexible laryngeal mask airway use during surgical burn management with head mobilisation: a feasibility study]

OBJECTIVE

To evaluate the feasibility and reliability of the flexible laryngeal mask airway (LMA flexible) use during scalp skin harvesting for surgical reparation of burn sequella.

STUDY DESIGN

Observational prospective descriptive study.

PATIENTS AND METHODS

Following local ethic committee approval, 26 patients were included in the study during their preanaesthesia visit. The general anaesthesia induction of each patient was followed by the insertion of a LMA flexible. The number of attempts required to insert the mask and the procedure were documented. The oropharyngeal leak pressure, expired tidal volume and end tidal CO(2) were recorded in five different head positions (neutral, hyperflexion, hyperextension, right and left rotation) at the start and end of surgical procedure. In all ten study periods of 2-3 min each were evaluated.

RESULTS

The airway device was inserted easily in all patients. While similar in four of the five head positions (neutral: 27.9+/-8.1 cmH(2)O, hyperextension, left and right rotation), the oropharyngeal leak pressure was significantly higher in the hyperflexion position (33.3+/-7.3 cmH(2)O). The end tidal volume was stable in all positions except hyperflexion (419+/-114 ml). While this value was significantly lower than the 471+/-68 ml recorded in the neutral position, it remained greater than 7 ml/kg. No significant change was observed for end tidal CO(2) for the ten study periods.

CONCLUSION

The use of LMA flexible during surgical burn repair procedures, including head mobilisation for the harvesting of scalp skin grafts is feasible.

An evaluation of the flexiguide introducer with the flexible laryngeal mask airway

Insertion of the flexible Laryngeal Mask Airway has been achieved by a variety of techniques. We have evaluated the Flexiguide for aiding introduction of a flexible Laryngeal Mask Airway in 100 anaesthetised patients. We were successful in establishing a clear airway on the first attempt on 84 (84%) occasions and within two attempts in 97 (97%). The positioning of the laryngeal mask airway was assessed by five measures and was optimally placed in 85% of cases and good in 96%. A clear airway was achieved in 92% of cases. Insertion of the flexible Laryngeal Mask Airway with the Flexiguide was easy in 82 (82%) and slightly difficult in 15 (15%) of cases. Removal of the Flexiguide from the device was easy in 95 (95%) of cases. Airway manoeuvres were used to assist airway placement in 55% of cases with jaw thrust being most common. Minor complications occurred in three (3%) patients: two coughed and one experienced minor tissue trauma during mask insertion. There were no complications associated with use of the Flexiguide during the procedure or after anaesthesia. The Flexiguide is a useful tool to assist insertion of the flexible Laryngeal Mask Airway and is associated with few complications.

The influence of head and neck position on oropharyngeal leak pressure and cuff position with the flexible and the standard laryngeal mask airway

We conducted a randomized, cross-over study of 20 paralyzed anesthetized adult patients to test the hypothesis that oropharyngeal leak pressure and cuff position (assessed fiberoptically) vary with head and neck position for the flexible (FLMA) and standard laryngeal mask airway (LMA). Both devices were inserted into each patient in random order. Oropharyngeal leak pressure and fiberoptic position (including degree of rotation) were documented in four head and neck positions (neutral first, then flexion, then extension and rotation in random order) for each device. The size 5 was used for all patients, and the intracuff pressure was set at 60 cm H2O in the neutral position. All airway devices were inserted at the first attempt. Oropharyngeal leak pressure was similar for the FLMA and LMA in the neutral (22 vs 21 cm H2O), flexed (26 vs 26 cm H2O), and extended positions (19 vs 18 cm H2O) but was slightly higher for the LMA when the head was rotated (19 vs 22 cm H2O; P = 0.04). Compared with the neutral position, oropharyngeal leak pressure for the LMA was higher with flexion (26 vs 21 cm H2O; P = 0.0004) and lower with extension (18 vs 21 cm H2O; P = 0.03) but similar with rotation. Compared with the neutral position, oropharyngeal leak pressure for the FLMA was higher with flexion (26 vs 22 cm H2O; P = 0.0001) and lower with extension (19 vs 22 cm H2O; P = 0.03) and rotation (19 vs 22 cm H2O; P = 0.03). The difference in oropharyngeal leak pressure between flexion and extension was 7 and 8 cm H2O for the FLMA and LMA, respectively. Fiberoptic position was similar between devices and was unchanged by head and neck position. Rotation was not detected fiberoptically. We conclude that there are small changes in oropharyngeal leak pressure but no changes in cuff position in different head and neck positions for the FLMA and LMA. Oropharyngeal leak pressure may be improved by head and neck flexion and by avoiding extension.

IMPLICATIONS

There are small changes in oropharyngeal leak pressure but no changes in cuff position in different head and neck positions for the flexible and standard laryngeal mask airways. Oropharyngeal leak pressure may be improved by head and neck flexion and by avoiding extension.