Effects of laryngeal mask airway on the hemodynamics of common carotid artery and internal carotid artery

Abstract

Objective To study the effects of laryngeal mask airway (LMA) on the hcmadynamics such as inner diameter , blood flow rate and volume of blood flow, etc of common carotid artery (CCA) and internal carotid artery(ICA) . Methods Sixty patients,aged 20-85y, weight 50-75 kg,with ASA grade Ⅰ-Ⅲ, undergone selective operation of laparoscopic cholecystectomy, were randomly allocated into two groups according to age: group A(20-59 y) and group B(60-85 y). Group A and group B were divided into A1 and B1 (cuff pressure: 20-30 cm H2O) (1 cm H20=0.098 kPa), A2 and B2 (cuff pressure: 40-50 cm H2O) respectively according to cuff pressure of 15 patients each. All the patients were given tracheal intubation and general anesthesia in operation. After the operation, patients were resuscitated in the Intensive Care Unit. Then the endotraeheal catheter was pulled out and LMA was inserted. Hemodynamics such as inner diameter, blood flow rate and volume of blood flow, ere of CCA and ICA , and vital sign were recorded before LMA insertion(T0) and at 3 min(T1), 10 min(T1) after insertion, and after pulling out(T3). Results The base points of inner diameter and volume of blood flow of CCA and ICA in group B were greater than those in group A(P 0.05). The volume of blood flow of CCA of group A and group B decreased by 9.3%-10.7% and 12.2%-19.1% respectively compared to T0(P<0.05). Group B2 decreased significantly among groups. The volume of blood flow of ICA of group A and group B decreased by 10.0%-13.5% and 13.9%-16.6% (P<0.05) respectively. At T3 time point, the above indexes returned to T0 level. Conclutions The volume of blood flow and inner diameter of CCA and ICA decrease a little when using LMA, which decrease significantly in old patients, but blood flow rate changes little. Key words: Laryngeal mask airway; Common carotid artery; Internal carotid artery; Haemedynamics; Anesthesia,general; Diameter of artery