Effects of remote limb ischemic preconditioning on lung injury in patients undergoing abdominal aortic aneurysm repair

Abstract

Objective To investigate the effects of remote limb ischemic preconditioning (RLIP) on the lung injury in patients undergoing abdominal aortic aneurysm repair.Methods Sixty-two ASA Ⅱ or Ⅲ patients of both sexes,aged 54-72 yr,with body mass index 21-36 kg/m2,undergoing elective abdominal aortic aneurysm repair,were randomly divided to 2 groups ( n =31 each):control group (group C) and RLIP group.RLIP consisted of two 5-min cycles of left upper limb ischemia induced by a blood pressure cuff placed on the left upper arm and inflated to 200 mm Hg,with an intervening 5 min of reperfusion,during which time the cuff was deflated.RLIP was performed after anesthesia induction and before the start of surgery.Arterial and venous blood samples were taken at 10 min after intubation (T0),and 30 min and 4,8,12 and 24 h after aortic unclamping (T1-5) for blood gas analysis and determination of the concentrations of serum interleukin (IL)-6,tumor necrosis factor (TNF)-α,and plasma malondialdehyde (MDA) and superoxide dismutase (SOD) activity.The alveolar-arterial oxygen pressure difference (PA-aO2 ) and respiratory index (RI) were calculated.The peak airway pressure (Ppeak),plat airway pressure (Pplat) and positive end expiratory pressure (PEEP) were recorded at the same time points mentioned above to calculate dynamic lung compliance (Cd) and static lung compliance (Cs).The incidence of hypoxemia,extubation time and duration of stay in intensive care unit (IGU) were also recorded.Results Compared with group C,PA-aO2,RI and the concentration of IL-6 were significantly decreased at T3-5,Cs,Cd and SOD activity were significantly increased at T2-5,and the concentrations of TNF-α and MDA were significantly decreased at T2-5 in group RLIP ( P ＜ 0.05).Compared with group C,the incidence of hypoxemia was significantly decreased,and extubation time and duration of stay in ICU were significantly shortened in group RLIP ( P ＜ 0.05).Conclusion RLIP can reduce the lung injury through inhibition of the inflammatory response and lipid peroxidation in patients undergoing abdominal aortic aneurysm repair. Key words: Upper extremity; Ischemic preconditioning; Respiratory distress syndrome, adult; Aortic aneurysm, abdominal