Clinical Studies for Respiratory Care

Ambu Laryngeal Mask

Articles:

Randomised crossover comparison of the Ambu AuraOnce Laryngeal Mask with the LMA Classic laryngeal mask airway in paralysed anaesthetised patients

Shariffuddin II, Wang CY. Department of Anaesthesia, Faculty of Medicine, University Malaya, Lembah Pantai, 59100 Kuala Lumpur, Malaysia.

Anaesthesia. 2008 Jan;63(1):82-5.

We compared the performance of the Ambu AuraOnce Laryngeal Mask with that of the LMA Classic laryngeal mask airway during controlled anaesthesia. Forty patients requiring intermittent positive pressure ventilation were studied using a randomised crossover design. The mean (SD) oropharyngeal leak pressure for the Ambu device (19 (7.5) cmH2O) was significantly greater than for the LMA Classic (15 (5.2) cmH2O; p = 0.004), and the number of attempts for successful insertions was significantly less (39 (50%) vs 45 (56%), respectively; p = 0.02). There was one failure to obtain a patent airway with the Ambu Laryngeal Mask and none with the LMA Classic. Insertion of the Ambu Laryngeal Mask required more manipulations to achieve a patent airway than did the LMA Classic (6 (15%) vs 1 (2.5%), respectively; p = 0.045), but the time taken for insertion was similar between the two groups. The incidence of trauma, grade of fibreoptic view, peak airway pressure and quality of ventilation during maintenance of anaesthesia were similar in both groups.

PMID: 18086075 [PubMed - in process]

Comparison of the AMBU Laryngeal Mask and the LMA Classic in anaesthetised, spontaneously breathing patients

Ng,SY., Teoh,WH., Lim,Y., Cheong,VG.

Department of Women’s Anaesthesia, KK Women’s and Childrens Hospital, Singapore

Anaesth Intensive Care (2007) 35 (1) 57-61

There may be a role for single-use laryngeal mask airways with concerns about inability to adequately sterilise laryngeal mask airways to eradicate prion proteins. A single-blinded prospective randomised controlled trial was conducted to compare the clinical performance of the single-use AMBU LMA with the reuseable LMA Classic. There was no difference in time to insertion, successful insertion at first attempt, oropharyngeal leak pressure, haemodynamic response to insertion or complications of placement.

The AMBU LMA was easier to insert. There was a suggestion of reduced postoperative sore throat and pharyngeal trauma for the AMBU LMA group. The AMBU LMA is a viable alternative to the LMA Classic for airway management in spontaneously breathing patients.

The article can be found at PubMed, a service of the US National Library of Medicine

A comparison of the disposable Ambu® AuraOnceTM Laryngeal Mask with the reusable LMA ClassicTM laryngeal mask airway.

By G.Sudhir, D. Redfern, JE Hall, AR Wilkes, C Cann.

Anaesthesia 2007 Jul;62(7):719-22 Department of Anaesthestics and Intensive Care Medicine, Wales College of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK. sudhirg@cf.ac.uk

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 article can be found on PubMed, a service of the U.S. National Library of Medicine

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

By Francksen,H, Bein,B, Cavus,E, Renner,J, Scholz,J, Steinfath,M, Tonner,PH, Doerges,V

Eur J Anaesthesiol. 2006 Aug 8;:1-7 (Epub ahead of print).

University Hospital Schleswig-Holstein, Department of Anaesthesiology and Intensive Care Medicine, Kiel, Germany.

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.

The article can be found at PubMed, a service of the U.S. National Library of Medicine

A Multicenter Study of the Ambu® Laryngeal Mask in Nonparalyzed, Anesthetized Patients.

By Carin A. Hagberg, MD, Frank Samsoe Jensen, MD, PhD., Harald V. Genzwuerker, Renée Krivosic-Horber, MD, Bettina U. Schmitz, MD, Jochen Hinkelbein, MD, Marius Contzen, MD, Herve Menu, MD and Karin Bourzoufi, MD.

Anesth Analg. 2005 Dec; 101(6):1862-6 Department of Anesthesiology, The University of Texas Medical School at Houston, 6431 Fannin Street, MSB 5.020 Houston, TX 77030. carin.a.hagberg@uth.tmc.ed.

We designed this multicenter trial to evaluate the performance and safety of the Ambu(R) laryngeal mask, a new disposable supraglottic airway device, in patients scheduled for elective surgery. One-hundred-eighteen nonparalyzed, anesthetized patients (ASA physical status I-II, age, 18-65 yr, body mass index, 18-30 kg/m(-2)) receiving total IV anesthesia were included in this study. After device insertion, fiberoptic position and oropharyngeal leak pressure were determined at an intracuff pressure of 60 cm H(2)O. Ease of ventilation was determined by controlling ventilation at 6 mL/kg tidal volume. Any complications were noted and recorded.

Device placement was successful in all patients on the first or second attempt (92.4% or 7.6%, respectively) with an insertion time (removal of face mask until first tidal volume) of 44.9 +/- 37.91 s. Adequate ventilation was achieved in all patients and the vocal cords could be visualized by fiberoptic endoscopy in 91.5% of patients. Oropharyngeal leak pressures were 24.1 +/- 5.44 cm H(2)O. Blood was detected on the device in 8.5% of patients. Complications and patient complaints were minor and quickly resolved. The Ambu laryngeal mask is easy and quick to insert and provides a safe and efficient seal during positive pressure ventilation in nonparalyzed patients scheduled for elective surgery.

Go to the National Library of Medicine’s Homepage.

A full reprint of the study can be obtained by contacting Ambu.

Comparison of two different laryngeal mask models for airway management in patients with immobilization of the cervical spine.

Jandewerth, O., Contzen, M., Hinkelbein, J., Genzwurker, H. Anaesthesist 2006. 55:263-269

This article is in German.

Abstracts & Posters:

Disposable laryngeal mask airway better or worse than the Classical LMA? A clinical feasibility study.

Jacobsson Jan, Doolke Anders, Saros Gun-Britt.

Karolinska Institutet Department of Anaesthesia, Foot & Ankle Surgical Centre, Stockholm Sweden.

Background. The laryngeal mask airway has become Gold Standard for airway management during Day Surgery. The Classical mask has recently been challenged by a variety of different disposable masks. The aim of the present survey was to evaluate in clinical routine practice the usefulness of two different disposable LMA; Ambu’s mask and Intersurgical’s mask

Conclusion. There are no major clinical differences between different laryngeal mask airways. The Ambu mask seems reassuringly easy to use.

You can download the full abstract here.

Comparison of AuraOnce and LMA-Unique as an intubation conduit in patients undergoing elective surgery.

Carin Hagberg, MD, Nicholas Lam, MD, Melissa Chan, MD, Dawn Iannucci, MS I, Allison Mahlstedt, BS.

Department of Anesthesiology, The University of Texas Medical School at Houston, Houston, Texas.

This study compared the AuraOnce to the disposable LMA (Unique; LMA North America, Inc., San Diego, CA) as an intubation conduit using a fiberoptically guided AIC.

50 ASA I-III, Mallampati I-III adult patients undergoing elective surgery received either the Unique (n=25) or the AuraOnce (n=25). The time to insert the LM (entering oropharynx until 1st capnograph breath), AIC (fiberscope enters LM until placed above carina) and ET intubation (laryngoscope enters oropharynx until 1st capnograph breath) was recorded. The number of attempts, seal pressures, and any intraoperative complications (i.e., laryngospasm, blood, coughing, etc.) as well as postoperative complications were also recorded. Both devices had similar minor intraoperative complications. In all patients, insertion of the LM and the AIC was successful within 3 attempts. One failure occurred in the AuraOnce group, in which the AIC was displaced while removing the LM. All other patients were successfully intubated using the study method.

Conclusion: The AuraOnce is comparable to the LMA Unique as an intubation conduit using a fiberoptically guided AIC. This technique is safe, effective, and easy to perform. Additionally, higher seal pressures were obtained with the AuraOnce, which may be beneficial for ventilation prior to the exchange, especially after failed laryngoscopy.

Presented at the Society for Airway Management's annual meeting on September 15-17, 2006 You can download the poster as a Ppt file here or the full abstract here.

Similar efficacy of the Ambu Laryngeal mask and LMA Unique during anaesthesia in children less than 30 kg.

Torsten Lauritsen, Renée Krivosic-Horber, Bruno Marciniak, Mark Thomas, Søren Walther-Larsen and Steen W. Henneberg.

In order to compare the efficacy of the Ambu Laryngeal Mask® (Ambu) with the LMA Unique® (Unique), we aimed to investigate non-paralysed infants/children with a weight of less than 30 kg in terms of insertion time in first attempt, insertion success rates, efficacy of seal, adequate positioning and intra- and postoperative complications.

No clinically relevant differences were seen when comparing Ambu Laryngeal Mask® to LMA Unique®. Therefore, personal preferences and price remain the most important factors when choosing between the two.

Presented at ESA 2006. Abstract no. A-632.

You can download the poster as a PDF file here

A clinical comparison of the Ambu AuraOnce™ and the LMA Unique™.

Gertrud Andersen, MD, David Tran-Van, MD, Yann Hervé, MD, Jette D. Brandt; CRNA

The Ambu AuraOnce (formerly called the Ambu laryngeal mask) is a disposable supraglottic airway device. In this randomised, single-blind, multi-centre study its performance was compared with the LMA Unique. ¨

The Ambu AuraOnceTM and LMA UniqueTM are equal in performance regarding handling and side effects. A higher oropharyngeal leak pressure in the Ambu AuraOnce group suggests a better airway sealing.

Presented at ESA 2006. Abstract no. A-1044

You can download the poster as a PDF file here

Economic considerations on reusable and single-use laryngeal mask airways: sample calculation based on clinical data of LMA-classic and ambu laryngeal mask.

C. Gernoth, O. Jandewerth, C. Konrad, H.V. Genswuerker

Besides reduction of infection risk, economic concerns are of increasing interest in the debate on single-use versus reusable products. In a clinical trial, LMA-Classic and single-Use Ambu laryngeal mask (ALM) are compared and analyzed. The maximum price for the single-use product to be competitive is 5.81 Euro.

Calculations on device economy should not be based on wholesale