雾化吸入地塞米松对肺损伤的影响

目的 探讨雾化吸入地塞米松(Dexamethasone)对盐酸(HC1)所致急性肺损伤(ALI)循环及呼吸功能的影响.方法 24头健康家猪,随机分为A、B、C三组,每组8头.麻醉及相关操作后记录平均动脉压(NAP)、平均肺动脉压(MPAP)、动脉氧分压(PaO2)、动脉二氧化碳分压(PaCO2)及肺顺应性作基础值,经气管导管向肺内注入0.1 mol/L的HCI溶液,直至PaO2＜13.3 kPa并持续30 min.A组维持原来的机械通气(间歇正压通气,IPPV),B组进行0.69 kPa呼气末正压通气,C组进行0.69 kPa PEEP通气基础上雾化吸入Dexamethasone,观察4 h.分别于Au前(T0)、Au时(T1)及Au后1h(T2)、2 h(T3)、3 h(T4)and 4 h(T5)记录上述指标.结果 三组MAP在ALI后均明显下降并维持在12 kPa(P＞0.05).三组MPAP在ALI后明显升高,A、B二组MPAP一直保持在(4.24±0.52)kPa(P＞0.05),而c组则明显下降至(3.22±0.25)kPa,较A、B组明显降低(P＜0.05).B、C两组的PaO2在13分组后较A组明显升高(P＜0.05),C组又明显高于B组(P＜0.05).A、B组PaCO2明显高于C组,A组又高于B组(P＜0.05).B、C组顺应性明显好于A组(P＜0.05),B、C组之间无差异(P＞0.05).结论 雾化吸入地塞米松能改善HCI所致ALI的呼吸功能,并在维持NAP平稳的情况下降低肺动脉压.

Effects of aerosdized dexamethsone inhalation on lurg injury

Objective To investigate the effects of aerosolized Dexamethsone inhalation on circulatory and respiratory function during lung injury (ALI) induced by hydrochloric acid (HCI) aspiration.Methods Twenty-four healthy pigs of either sex,weighting (15.5±2) kg were anesthetized with intraperitoneal injection of pentobarbital sodium 50mg/kg and intubated and mechanically ventilated (FiO2=1.0,VT=10-15 ml/kg,RR=16bpm,I:E=1:2).Anesthesia was maintained with infusion of Ketamine,procaine and succinylcholine.Femoral artery was cannulated for MAP monitoring and blood sampling.Swan-Ganz catheter was placed in the pulmonary artery via right inexternal jugular vein.Dilute HC1 (0.1mol/L) was instilled via trachea into lungs until PaO2 was＜13.3kPa.Arterial blood gases,MAP,MPAP and dynamic compliance were measured before induction of ALl (T0),when ALI was induced (T1) and 1,2,3 and 4(T2～5)there after.The pigs were then divided randomly into three groups according to the treatment they received:group A received IPPV alone,group B IPPV+PEEP(0.69kPa) ,group C IPPV+PEEP(0.69kPa)+aerosolized Dexamethasone (12.5ugokg-loh-I).Results MAP decreased significantly after induction of ALI in three groups hut there was no significant difference in MAP among the three groups (P＞0.05).MPAP increased significantly after induction of ALI in all groups and remained high during the period of T2～5 in group A and B (P＞0.05),hut decreased significantly from T2 in group C (P＜0.05 ).PaO2 increased significantly during the treatment in group B、C(P＜0.05),and was significantly higher in group C than that in group B (P＜0.05).PaCO2 in group A was highest in three groups (P＜0.05) and group C was lower in three groups (P＜0.05).Dynamic lung compliance decreased in all animals after induction of lung injury (P＞0.05),but was gradually increasing significantly during treatment(B、C group) (P＜0.05).Conclusion Aerosolized Dexamethasone inhalation can improve respiratory function during ALI induced by HC1 aspiration and reduce pulmonary hypertension,but dont impair MAP.Both have the same effects on the treatment of lung injuries.