A comparison of the Soft Sealtm disposable and the Classic re-usable laryngeal mask airway*

Effective Dose of Remifentanil for Control of Haemodynamic Response to Insertion of the Streamlined Liner of the Pharyngeal Airway

Objective

To determine the dose of remifentanil needed to achieve successful insertion of the Streamlined Liner of the Pharyngeal Airway (SLIPA™) without the development of hypertension in 95% of the patients.

Design

Randomised controlled trial.

Setting

operating theatre of a university hospital

Methods

A total of 100 ASA I or II patients requiring SLIPA insertion were randomly assigned to receive normal saline (Group C) or one of the four different doses (0.5 µg/kg [Group R0.5], 1.0 µg/kg [Group R1], 1.5 µg/kg [Group R1.5] or 2.0 µg/kg [Group R2]) of remifentanil. Arterial blood pressure and heart rate were recorded at preanesthetic baseline, preinserton, and every one minute during the initial 3 minutes period after insertion.

Results

A Probit model of remifentanil concentration was predictive of successful insertion of SLIPA without the development of hypertension. The ED95 of remifentanil needed to suppress haemodynamic response from SLIPA insertion was 1.39 µg/kg (95% confidence interval, 1.06-2.61 µg/kg).

Conclusions

A single administration of remifentanil can effectively suppress haemodynamic changes due to the insertion of SLIPA.

Laryngeal mask airway insertion by classic and thumb insertion technique: a comparison

We evaluated the efficacy of an alternative technique, for insertion of the silicone laryngeal mask airway (LMA) Classic™ in 40 American Society of Anesthesiologists grade ASA I and II patients scheduled for elective surgery. In group I (Index Finger group), the LMA was inserted by the classic index finger technique and, in group T (Thumb Insertion group), the thumb insertion technique was used. Ease of insertion, fiberoptic laryngoscopic position, cuff pressures and laryngopharyngeal morbidity were assessed in both study groups. On statistical analysis, both groups were comparable in all respects. From our study it can be concluded that thumb insertion is an effective insertion technique for the LMA Classic™.

The air-Q(®) intubating laryngeal airway vs the LMA-ProSeal(TM) : a prospective, randomised trial of airway seal pressure

We performed a prospective, open-label, randomised controlled trial comparing the air-Q(®) against the LMA-ProSeal™ in adults undergoing general anaesthesia. One hundred subjects (American Society of Anesthesiologists physical status 1-3) presenting for elective, outpatient surgery were randomly assigned to 52 air-Q(®) and 48 ProSeal devices. The primary study endpoint was airway seal pressure. Oropharyngolaryngeal morbidity was assessed secondarily. Mean (SD) airway seal pressures for the air-Q(®) and ProSeal were 30 (7) cmH (2) O and 30 (6) cmH(2) O, respectively (p = 0.47). Postoperative sore throat was more common with the air-Q(®) (46% vs 38%, p = 0.03) as was pain on swallowing (30% vs 5%, p = 0.01). In conclusion, the air-Q(®) performs well as a primary airway during the maintenance of general anaesthesia with an airway seal pressure similar to that of the ProSeal, but with a higher incidence of postoperative oropharyngolaryngeal complaints.

Supraglottic airway devices in the ambulatory setting

Supraglottic airway devices (SGAs) offer certain advantages over endotracheal intubation, making them particularly well suited for the specific demands of outpatient anesthesia. Patients may tolerate the placement and maintenance of an SGA at a lower dose of anesthetic than that needed for an endotracheal tube; neuromuscular blocking agents are rarely necessary for airway management with an SGA; the incidence of airway morbidity is lower with SGAs than with endotracheal tubes; and SGAs may facilitate faster recovery and earlier discharge of patients. Two limitations of SGAs are incomplete protection against aspiration of gastric contents and inadequate delivery of positive pressure ventilation. Newer variants of the original laryngeal mask airway, the LMA Classic (LMA North America, Inc), as well as an array of other recently developed SGAs, aim to address these limitations. Their utility and safety in specific patient populations (eg, the morbidly obese) and during certain procedures (eg, laparoscopic surgery) remain to be determined.

The Soft Seal disposable laryngeal mask airway in adults: comparison of two insertion techniques without intra-oral manipulation

We investigated whether insertion of the disposable Soft Seal laryngeal mask airway (SSLM) was successful without intra-oral digital manipulation. One hundred patients undergoing anaesthesia using the SSLM were randomly assigned into two groups. Insertion was performed by either a direct or a rotational technique, both without intra-oral digital manipulation. The primary outcome measure was successful insertion at first attempt. Other outcomes included insertion time, fibreoptic assessment of the airway view and airway morbidity. The first attempt success rate was higher (98%) with the direct technique than with the rotational technique (75%; p = 0.002) but insertion time was faster with the latter method (mean [range] 15 [8-50] s) than with the direct method (20 [8-56] s; p = 0.035). Fibreoptic assessment and airway morbidity were similar in both groups. We conclude that the SSLM can be successfully inserted without intra-oral digital manipulation.

A comparison of the disposable Ambu�AuraOnce?Laryngeal Mask with the reusable LMA Classic?laryngeal mask airway

Single-use supraglottic airway devices are now available and are intended to be comparable with the reusable LMA Classic laryngeal mask airway. We performed a randomised cross-over study comparing the Ambu AuraOnce Laryngeal Mask with the LMA Classic. Fifty patients participated in the trial. Success rates for insertion at the first attempt were similar (92% with the Ambu and 84% with the LMA Classic; p = 0.22). The volumes of air required to inflate the cuff to produce a seal were similar, but the cuff pressure was lower for the Ambu Laryngeal Mask (median (IQR [range]) 18 (10-31 [0-100] cmH(2)O) than the LMA Classic 27 (17-50 [4-90] cmH(2)O; p = 0.007). Visual analogue scores for ease of insertion were 87 (73-93 [26-97]) mm for the Ambu and 84 (60-89 [18-96]) for the LMA Classic (p = 0.017). Complications were similar in both groups. We suggest that the disposable Ambu Laryngeal Mask is an acceptable alternative to the reusable LMA Classic.

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.

Comparison of LMA Unique, Ambu laryngeal mask and Soft Seal laryngeal mask during routine surgical procedures

BACKGROUND AND OBJECTIVE

This study was performed to compare three disposable airway devices, the LMA Unique (LMA-U), the Ambu laryngeal mask (Ambu LM) and the Soft Seal laryngeal mask (Soft Seal LM) for elective general anaesthesia during controlled ventilation in non-paralysed patients.

METHODS

One hundred and twenty ASA I-III patients scheduled for routine minor obstetric surgery were randomly allocated to the LMA-U (n = 40), Ambu LM (n = 40) or Soft Seal LM (n = 40) groups, respectively. Patients were comparable with respect to weight and airway characteristics. A size 4 LMA was used in all patients and inserted by a single experienced anaesthesiologist. Oxygenation, overall success rate, insertion time, cuff pressure and resulting airway leak pressure were determined as well as a subjective assessment of handling and the incidence of sore throat, dysphagia and hoarseness.

RESULTS

Time of insertion was shortest with the Ambu LM, while failure rates were comparable with the LMA-U, the Ambu LM and the Soft Seal LM (median 19 s; range 8-57 s; success rate 100% vs. 14; 8-35; 97% vs. 20; 12-46; 95%). Insertion was judged 'excellent' in 75% of patients in the LMA-U group, in 70% of patients in Ambu LM group and in 65% of patients in the Soft Seal LM group. There was no difference between devices with respect to postoperative airway morbidity at 6 h or 24 h following surgery.

CONCLUSIONS

All three disposable devices were clinically suitable with respect to insertion times, success rates, oxygenation, airway and leak pressures, as well as to subjective handling and postoperative airway morbidity.

Masques laryngés à usage unique vs réutilisable : une étude de minimisation de coûts

JUSTIFICATION

According to French regulations concerning the risk of Creutzfeldt-Jakob disease transmission, traceability procedures of all sterile medical devices which need to be reused are mandatory. Despite sterilization processes, the reusable laryngeal mask airway (LMA) prion disease transmission remains possible. As a result, the disposable LMA has been introduced.

OBJECTIVE

Assuming clinical equivalence was achieved, the cost of disposable vs reusable LMA was studied in a university hospital.

STUDY DESIGN

A Cost-minimization analysis of disposable vs reusable laryngeal mask airway was realised.

METHODS

Disposable LMA cost was calculated as the sum of product cost and elimination cost. Reusable LMA were autoclaved after hospital purchasing in two separate sterilizing processing units of the same hospital. Reusable LMA cost was determined combining materiel and labor costs.

RESULTS

The reusable LMA cost depended on the sterilizing processing unit concerned and varied between 9.59 Euros and 9.69 vs 8.38 Euros for the single-use LMA.

CONCLUSION

With the cost savings made possible by use of disposable LMA in both labor and consumables, this practice should be considered.