Klinische Studies voor Luchtweg Behandeling

Ambu Larynx Masker

ARTIKELEN

Clinical and endoscopic comparison of the single use laryngeal mask (AuraOnce™), with the flexible laryngeal mask (Auraflex™) in three different positions of the head
 

By M. Enric, G. Antonio, B. Ester, M. Maged. Anesthesia, Hospital Sant Joan de Deu, Esplugues de Llobregat, Barcelona, Spain

Clinical and endoscopic performance of a laryngeal mask can be modified if the patient's neck is flexed or extended. The aim of the study is to compare clinical and endoscopic parameters of these two devices in three different positions of the head (neutral, extension and flexion).

Materials and Methods: 61 pediatric patients were enrolled in this study. They were divided into two groups: Group A (single use LM): n=32, age 48 ±16, weight 16,03±3,35. Group B (flexible LM): n= 29, age 44±20, weight 15,5 ±3,23. After inhalatorial induction, we inserted a # 2 LM. Under spontaneous ventilation, we measured leak pressure and evaluate glottic view with a 3.8 fibroscope. Glottic view was classified into three different groups (complete, partial or poor). Leak pressure and glottic view were evaluated in each position (neutral, extension and flexion).
Conclusion(s): Clinical and endoscopic evaluation of a laryngeal mask can be modified if we change the position of the head. These changes are relevant, and can reach up to 50% in A group, while seems to be lower in the flexible group. Endoscopic view is also modified in both groups but more in the single use group than in flexible one. It seems that the flexibility of the tube permits better fitting of the mask to pharynx anatomy, when patient's neck is extended or flexed.

Presented at ESA, June 2008.

 

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.

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

Study of the adjustment of the Ambu laryngeal mask under magnetic resonance imaging.

Monclus E, Garcés A, De Jose Maria B, Artés D, Mabrock M.

BACKGROUND: Our aim in this study was to analyze the adjustment of the laryngeal mask, Ambu AuraOnce, in pediatric patients during magnetic resonance imaging (MRI) and to look for a correlation between clinical parameters such as the sealing pressure and the ease of introduction with radiological parameters.
METHODS: One-hundred and twenty-one pediatric patients from 4 months to 17 years who required a cranial MRI for other reasons were enrolled in the study. General anesthesia was induced with sevofluorane and no relaxant was used. Insertion attempts, sealing pressure, desaturation episodes and maintenance of anesthesia were recorded. Spontaneous ventilation was maintained throughout all procedures and no episodes of desaturation below 95% were seen. Patients without cough or pharyngeal pain were discharged after 1 h. Data were classified into three groups according to the size of the used laryngeal mask (group 1 for laryngeal mask number 1(1/2); group 2 for laryngeal mask number 2, and group 3 for laryngeal mask number 2(1/2)). Sagittal MRI cuts were reviewed to calculate neck flexion, laryngeal mask position and its relationship with the trachea.
RESULTS: First-attempt introduction rate of the laryngeal mask was 96%, and it was 100% after a second attempt. Sealing pressure was 22.1+/-4.15 mmHg for group 1, 22.23+/-3.94 for group 2, and 23.83+/-3.28 for group 3. The angles between the laryngeal mask and the four first cervical vertebrae were calculated (group 1, 33.65+/-8.05; group 2, 28.09+/-6.65; group 3, 25.79+/-4.26). Distances between trachea and proximal and distal cuffs were measured to evaluate proper fitting of the laryngeal mask. Anomalous placement seen on MRI, using distances from proximal and distal cuff to trachea, occurred in 23.5% in group 1, 10.9% in group 2, and 13.8% in group 3. We found no correlation between this anomalous position of the laryngeal mask and sealing pressure or ease of introduction.
CONCLUSIONS: The Ambu AuraOnce can be regarded as a safe product for airway maintenance in pediatric patients. No relationship was found between radiological measurements and sealing pressures.

Study Published in Paediatr Anaesth. 2007 Dec;17(12):1182-6.
 

Ambu Laryngeal Mask vs. Laryngeal Mask Unique: Evaluation of two modified disposable ventilatory devices

H. Francksen, B. Bein, T Obermoller, J Scholz and V Dorges.

The purpose of the study was to asses the recently developed Laryngeal Mask Unique (LMA-U) and the Ambu Laryngeal Mask (Ambu LM) in routine clinical practice.
Eighty patients undergoing minor gynaecological surgery were incorporated into the investigation. Time of insertion and failure rate was comparable between the LMA-U and Ambu LM (time of insertion median LMA-U: median 22 sec, range 8 – 57 sec, vs Ambu LM: median 16 sec, range 8 – 35 sec, failure rate: LMA-U: 0/40 and Ambu LM: 1/40). Blood gas samples and ventilation variables revealed sufficient ventilation and oxygenation with either device. Paw (LMA-U: median 14 cm H2O, range 6 – 20 cm H2O, vs Ambu LM: median 14 cm H2O, range 9 – 23 cm H2O) was comparable between the masks and airway leak pressure (LMA-U: median 16 cm H2O, range 5 – 28 cm H2O, vs Ambu LM: median 18 cm H2O, range 12 – 38 cm H2O) was higher with Ambu LM compared to LMA-U. Post operative airway morbidity was also comparables between the groups and no gastric inflation was observed with either device.
Conclusion: Using LMA-U and Ambu LM resulted in comparable ventilation and oxygenation variables. Both newly developed disposable devices may be simple alternatives to secure the airway in routine minor surgical procedures.

Eur J Anaesthesiol. 2007 Feb;24(2):134-40. Epub 2006 Aug 8.
 

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

Recommended inflation volumes result in lower cuff pressure in paediatric patients with Ambu AuraOnce when compared to LMA-Classic.

By Dr. Harald Genzwuerker

Background and Goal of Study: Two laryngeal masks, LMA-Classic and the single use Ambu AuraOnce are compared for ventilation in paediatric patients. Besides ease of insertion, the cuff pressures resulting when recommended inflation volumes are applied are assessed.

Material and Methods: After approval of the local ethics committee and written consent of guardians, 100 ASA I/II patients, 2 to 8 years, scheduled for elective ambulatory interventions were randomised to be ventilated with LMA or AuraOnce. Following standardized induction of general anaesthesia, the completely deflated airway device were placed according to manufacturer’s instruction. Cuff were inflated with 10 ml for size 2, 14 ml for size 2,5, and 20 ml for size 3. Number of attempts (max 2) , time until first tidal volumen, initial cuff pressure and intraoperative tidal volumes (goal: petCO2 of 35 mmHg) were recorded. Cuff pressure were adjusted to 60cmH2O for measurement of airway leak pressure. Device were inspected for trace of blood after removal. Patients were questioned for postoperative complaints.

Results and Discussions: 50 patients were ventilated with either device. Average age was 5,1(2.2-8.0) for LMA and 5.1 (2.5-7.9) years for AuraOnce. 44 patients in the LMA group and 48 patients in the Aura group were male. Weight, height, baseline, heart rate, blood pressure and oxygen saturation were comparable for both groups. Size 2 was used in LMA/Aura in 7/4, size 2.5 in 41/45 and size 3 in 2/1 patients. Insertion was successful in all patients (first attempt LMA 45, Aura 47). Time until first tidal volume for LMA and Aura was 8.72.3 and 8.02.3 seconds. Initial cuff pressure were 104.219.0 cmH2O for LMA and 74.424.3 cmH2O for Aura (p<0.001). Tidal volumes were 8.7 and 9.1ml kg-1 for LMA and Aura, airway leak pressures were 32.79.4 and 34.18.4 cmH2O. Intraoperative dislocation occurred in 1 LMA patient. No traces of blood were found after removal of the devices. No postoperative complaints were stated.

Conclusion(s): In paediatric patients, LMA Classic and Ambu AuraOnce are found to be comparable in all respects except cuff pressures resulting from recommended inflation volumes. Excess of maximum recommended cuff pressure is considerably higher with the LMA-Classic.

Presented at ESA 2007.

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 mas