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A-1422
2004
A Randomized, Prospective Comparison of Laryngeal Tube and Laryngeal Mask Airway in Pediatric Patients Undergoing Elective Interventions
Harald V. Genzwuerker, M.D., Andreas Fritz, M.D., Thorsten Finteis, M.D., Elke Thil, M.D., Hans-Juergen Rapp, M.D.
Inst. of Anesthesiology and Intensive Care Medicine, University Hospital Mannheim, Mannheim, Germany.
Objective: Reports on use of the laryngeal mask airway (LMA-Classic™, LMA Company) in a large number of pediatric patients are available (1), while data on the use of the laryngeal tube (LT, VBM Medical) in this age group is limited. In a prospective, randomized clinical trial the two devices are compared for ease of insertion, success rate and quality of airway seal.

Methods: After obtaining approval of the institutional review board and written informed consent of the guardians, 60 children, age 2-8 years, scheduled for elective surgical interventions, randomized themselves to be ventilated with either LMA or LT by pulling a card from a bag. After induction of general anaesthesia with fentanyl and propofol, airway devices were placed according to manufacturer´s instructions. Number of attempts (maximum 2), insertion time, time until first tidal volume and intraoperative tidal volumes with an etCO2 of 35 mmHg were recorded. Airway leak pressure was measured with cuff pressures set to 60 cmH2O. After removal, devices were inspected for traces of blood and patients were questioned for hoarseness or soar throat.

Results: No differences were found for demographic data, baseline and intraoperative parameters (table 1 and 2). Insertion was successful in 29 out of 30 patients in the LMA-group (96.7 %, first attempt 21, second attempt 8) and in all patients in the LT-group (100.0 %, first attempt 27, second attempt 3). Insertion time and time until first tidal volume for LMA/LT was 11.6 ± 6.8/10.1 ± 7.2 seconds (n.s.) and 23.1 ± 7.3 / 19.2 ± 8.6 seconds (p<0.05). Peak airway pressures for LMA and LT were 15.3 ± 3.4 and 17.1 ± 4.0 cmH2O (p<0.05) with tidal volumes of 10.2 ± 2.2 and 10.2 ± 1.9 ml kg-1, airway leak pressure was 19.2 ± 8.6 and 26.3 ± 7.3 cm H2O (p<0.001). Anesthesia time was 73.5 min for LMA and 81.7 min for LT. Traces of blood were found after removal in 7 LMAs and 4 LTs, mild complaints of hoarseness or soar throat were found in the recovery room in 4/6 patients and after 24 hours in 1/2 patients for LMA/LT.

Conclusions: Insertion success is high with both laryngeal mask airway and laryngeal tube in the age group studied. The airway leak pressure, serving as an estimate to judge quality of airway seal, is higher with the laryngeal tube. Postoperative complaints are infrequent and mild.

References:

(1) Lopez-Gil M Anaesthesia 1996;51:969-72

Anesthesiology 2004; 101: A1422
Demographic data
LMALT
Patient sex21 boys/9 girls25 boys/5 girls
Age (years)5.2 ± 1.85.3 ± 1.9
Weight (kg)19.4 ± 5.821.0 ± 5.6
Height (m)1.09 ± 0.131.13 ± 0.13
Hemodynamic variables (baseline and 10 minutes after induction)
(baseline / after 10 minutes)LMALT
Heart rate (bpm)102.6 ± 14.7 / 87.5 ± 17.097.5 ± 15.6 / 89.0 ± 20.6
Systolic blood pressure (mm Hg)95.2 ± 11.0 / 82.8 ± 8.996.6 ± 13.3 / 89.4 ± 9.8
Peripheral oxygen saturation (%)97.4 ± 1.8 / 99.8 ± 0.497.2 ± 2.1 / 99.9 ± 0.3