Influence of different head and neck positions on airway sealing pressure with i-gel laryngeal mask airway in patients undergoing elective surgery under general anesthesia with mechanical ventilation
10.3760/cma.j.issn.0254-1416.2012.04.022
- VernacularTitle:不同头颈位置时i-gel喉罩对全麻手术患者气道密封压和通气效果的影响
- Author:
Jun ZHANG
;
Haonan MA
;
Licheng GENG
- Publication Type:Journal Article
- Keywords:
Laryngeal masks;
Posture;
Head;
Pulmonary ventilation
- From:
Chinese Journal of Anesthesiology
2012;32(4):471-473
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the influence of different head and neck positions on airway sealing pressure (OLP) with i-gel laryngeal mask airway (LMA) in patients undergoing elective surgery under general anesthesia with mechanical ventilation.Methods Thirty ASA Ⅰ or Ⅱ patients of both sexes aged 32-64 yr with a body mass index of 18-30 kg/m2 undergoing elective surgery under general anesthesia with LMA were studied.Size 4 i-gel LMA was placed blindly after induction of anesthesia and connected to anesthetic circuit.The criteria for successful placement were easy inflation with small leak,peak inspiratory pressure (PPeak) within normal range and normal PETCO2 wave form.Fiberoptic bronchoscopy was performed to check the position of LMA.OLP,expiratory tidal volume ( VTE ),PPeak and efficiency of mechanical ventilation were measured in different head and neck positions.OLP was measured by gradually increasing airway pressure until PPeak was reached.The measurement was stopped when there was large leak or OLP ＞ 35 cm H2 O.The efficacy of ventilation was evaluated by manually inflating the lungs (perfect:easy inflation,no audible leak; satisfactory:easy inflation,small leak; poor:difficult inflation,large leak).Results Flexion of the head significantly increased OLP and PPeak and decreased VTE,while hyperextension significantly decreased OLP and PPeak and increased VTE as compared with middle position of the head.Lung ventilation was less satisfactory when the head was flexed.Turning the head to either side did not affect ventilation.Conclusion Flexion of the head should be avoided when i-gel LMA is used during anesthesia.
