Supplementary cleaning does not remove protein deposits from re-usable laryngeal mask devices

Comparison of the Re-usable LMA Classic™ and Two Single-use Laryngeal Masks (LMA Unique™ and SoftSeal™) in Airway Management by Novice Personnel

In a single-blind randomized trial, three types of laryngeal masks: the reusable LMA Classic™, the single-use LMA Unique™ and SoftSeal™ were inserted by novice medical officers in anaesthesia. Five successive attempts were undertaken with each mask type. The order of the mask type insertion was randomly selected. Mean (SD) insertion times for LMA Classic™, LMA Unique™ and Soft Seal™ were 32.9 (12.3), 39.6 (23.4) and 49.4 (50.4) seconds respectively. Differences were only significant between LMA Classic™ and SoftSeal™ (P=0.012). There were no significant differences in first attempt success rates (LMA Classic™ 80%, LMA Unique™ 77% and SoftSeal™ 62%). The SoftSeal™ was most frequently associated with blood on the mask (32%) compared to the LMA Unique™(9%) and LMA Classic™ (6%). Sore throat was experienced in 14% of patients in the LMA Unique™ group versus 41% and 42% in the LMA Classic™ and SoftSeal™ groups respectively. Mean±SD oropharyngeal leak pressure was significantly higher in the SoftSeal™ (21±6 cmH2O) compared to the LMA Classic™ (17±7 cmH2O) and LMA Unique™ (16±6 cmH2O).

Novice medical doctors can be taught to insert disposable laryngeal masks. The SoftSeal™ took longer to insert, which resulted in a higher incidence of blood on the mask, but success rates did not differ. The LMA Unique™ was associated with the lowest incidence of sore throat in the immediate postoperative period. A higher oropharyngeal leak pressure with the SoftSeal™ may indicate improved airway seal and protection against aspiration.

Influence of the collection and oxygenation method on quantitative bacterial composition in bronchoalveolar lavage fluid samples from healthy dogs

The purpose of the study was to evaluate the effects on quantitative and qualitative microbial content of endoscopic bronchoalveolar lavage fluid (BALF) in healthy dogs using a laryngeal mask airway (LMA). It was hypothesised that oropharyngeal protection might prevent contamination of BALF with oropharyngeal microflora. Ten healthy Beagle dogs were randomly assigned to two groups and underwent endoscopic BAL on two occasions, either via an open unprotected oropharynx with oxygen supply provided via a nasal catheter (NT) or through a sterile LMA. For the second sampling, groups were switched. BALF analysis included quantitative microbial culture, nucleated cell counts and cytology. The mean (+/-SD) number of colony forming units (CFU)/mL found in the BALF using the LMA was 25,610+/-22,943 in the right lung (RL) and 22,510+/-18,779 in the left (LL). With the NT technique, the figures were 21,068+/-19,375 for the RL and 16,060+/-15,523 for the LL, respectively. Nucleated cell counts/microL were 691.0+/-181.6 (RL) and 734.0+/-171.6 (LL) for LMA, and 772.0+/-251.0 (RL) and 748+/-163.2 (LL) for NT. No significant differences were detected either in the number of CFU/mL or in the diversity of bacterial species with the two methods. A significant increase in BALF bacterial counts (with reduced species diversity) was observed on the second compared to the first sampling regardless of the method used. Protection of the oral cavity and oropharynx using an LMA had no significant influence on BALF bacterial counts. The findings suggest that with careful endoscope insertion, the risk of contamination of BALF by resident and transient oropharyngeal microflora can be negligible.

Comparison of the single use and reusable intubating laryngeal mask airway

We compared the times to intubate the trachea using the single use (Group S) and reusable (Group C) intubating laryngeal mask (ILMA(TM)), in 84 healthy patients with normal airways undergoing elective gynaecological surgery. There was no significant difference in the ease of insertion of the ILMA or the tracheal tube, or time to successful insertion (Group S, 101.4 s (SD 63.2) vs Group C, 90.4 s (SD 46.1), p = 0.366). The ILMA was successfully inserted on first attempt in 63% of Group S patients and in 68% of Group C patients. After one or two attempts the overall success rate for both groups was 93%. There was a failure to insert the ILMA in two patients in each group. There was no difference in side-effects (desaturation S(p)o(2) < 95%, bleeding, oesophageal intubation, lip, dental or mucosal injury, or sore throat postoperatively). We conclude that the disposable ILMA is an acceptable alternative to the reusable ILMA.

The effectiveness and patient comfort of the novel streamlined pharynx airway liner (SLIPA) compared with the conventional laryngeal mask airway in ophthalmic surgery

BACKGROUND

The novel, disposable streamlined pharynx airway liner (SLIPA) has recently been introduced into clinical practice. It has no inflatable cuff, because the shape of the SLIPA closely resembles the anatomy of the pharynx.

METHODS

We compared the SLIPA with the conventional laryngeal mask airway (LMA) regarding handling, safety, sealing of the pharynx, and patient comfort in 124 adult patients (ASA I-III) undergoing ophthalmic surgery under general anesthesia.

RESULTS

Insertion of the SLIPA was straightforward in 88%, slightly difficult in 10%, and obviously difficult in 0% of cases. The SLIPA could not be inserted in 2% of patients. In the LMA group, insertion was straightforward in 90%, slightly difficult in 8%, obviously difficult in 2%, and a failure in 0% of patients. Maximum seal pressure was 24 +/- 6 mm H2O with the SLIPA and 24 +/- 4 mm H2O with the LMA. Gastric air insufflation was noticed in 19% of patients in the SLIPA group and 3% in the LMA group (P < 0.05). No regurgitation of gastric contents was observed. Removal of the airway was uneventful in all cases. Blood traces were noted on the surface of the device in 20% in the SLIPA versus 11% (n.s.) in the LMA group. Complaints of a sore throat were recorded in 2% vs. 14% in the SLIPA and the LMA group, respectively.

CONCLUSION

The SLIPA is a useful alternative to the conventional LMA in patients undergoing minor surgery. However, it is associated with a higher incidence of gastric air insufflation, which may increase the risk of aspiration.

Vergleich von zwei Larynxmaskenmodellen zur Atemwegssicherung bei Patienten mit Immobilisation der Halswirbelsäule

BACKGROUND

Reduced cervical spine mobility can impair laryngoscopy and tracheal intubation. Supraglottic airway devices can be important alternatives for oxygenation under these circumstances. The Ambu laryngeal mask (ALM) and the LMA-Classic (LMA) are compared in patients with immobilization of the cervical spine.

METHODS

In 60 patients scheduled for elective ambulatory interventions, ALM or LMA were inserted after cervical immobilization with an extrication collar and assessment of laryngoscopic view. Insertion time (removal of facemask until first tidal volume), number of insertion attempts, airway leak pressure (cuff pressure 60 cm H(2)O), intraoperative complications and postoperative complaints were assessed.

RESULTS

Demographical data, insertion attempts, insertion time (ALM 15.6+/-4.4 s, LMA 15.5+/-4.9 s) and airway leak pressure (ALM 25.6+/-5.2 cm H(2)O, LMA 26.5+/-6.5 cm H(2)O) were comparable. Traces of blood were found in 6 LMAs and 3 ALMs after removal, mild trouble with swallowing (visual analogue scale, VAS 2-4) in the recovery room and after 24 h were complaints by 1 ALM and 2 LMA patients.

CONCLUSIONS

LMA-Classic and Ambu laryngeal masks are suitable for rapid and reliable airway management in patients with cervical immobilization.

[Clinical evaluation of the single use Laryngeal Tube in adults: the LTD]

OBJECTIVES

The Laryngeal Tube (LT) is a supra-laryngeal device indicated to manage upper airway during anaesthesia. Leak pressures were lately reported higher for the LT as compared to the LMA. A recent study found a small amount of proteinaceous material on LMA after classical sterilization suggesting a risk of contamination by unconventional transmissible agents (prions). The aim of this study was to evaluate the effectiveness of the single use Laryngeal Tube: the LTD.

STUDY DESIGN

Prospective study realized after ethical committee agreement and patient consent for participation.

PATIENTS AND METHODS

Adults, ASA score< or =3, 18 to 75-year-old, without upper airway abnormality or difficult intubation criteria, anaesthesia< or =2 h, free access to patient's head and LTD. The following criteria were evaluated: easiness of insertion, assisted (AV), controlled (CV) and spontaneous ventilation (SV); leak pressure (LP) 5 and 15 min after insertion; complications during anaesthesia conducted with propofol and remifentanil under bispectral index monitoring.

RESULTS

55 patients were included; only one failure was reported at insertion. AV and CV were easy, SV difficult in 4 patients with chin lift necessary for adequate ventilation. LP was 28.92+/-8.4 and 30.87+/-8.68 cmH2O 5 and 15 min after insertion respectively. No major incident was noticed throughout the study.

CONCLUSION

the use of the LTD was easy and successful. Moreover the LTD totally excluded the risk of contamination by unconventional transmissible agents.