目的　探讨含氯胺酮的肺表面活性物质剂 (PS)对洗肺鼠呼吸衰竭的作用。方法　 2 0只Wistar大鼠经戊巴比妥钠腹腔内麻醉后 ,经气管切开孔插入导管行人工呼吸。吸气峰压 (PIP)定为1 47kPa ,吸呼比为 1:1。将PIP及呼气终末正压 (PEEP)分别调至 1 96kPa和 0 49kPa后对所有动物行全肺灌洗 (37℃生理盐水 ,40ml·kg-1) 8～ 10次。当动脉血氧分压 (PaO2 )降至 12kPa以下时 ,将动物随机分为A组及B组 ,每组各 10例。A组的动物经气管注入单纯的PS 2 5mg(0 5ml) ;B组则注入含有氯胺酮 2 5mg的PS 2 5mg(0 5ml)。 12 0min后撤离PEEP ,并将PIP调至 1 47kPa。结果　所有动物的PaO2经肺灌洗后由 5 9 4kPa降至 10 3kPa左右 (P <0 0 5 )。治疗后两组的PaO2均明显升高至肺灌洗前水平 (5 6 3kPa) (P <0 0 5 )。当撤离PEEP后 ,与灌洗前相比 ,A组的PaO2 明显下降至 2 0kPa以下 (P <0 0 5 ) ,而B组的则保持在 46kPa以上 (P >0 0 5 )。至实验结束时 ,B组的动物全部存活 ,而A组只有 4例存活。结论　含氯胺酮的肺表面活性物质剂能较好地维持无PEEP的低气道内压下呼吸衰竭大鼠的呼吸功能 Objective To investigate the effect of ketamine-containing pulmonary surfactant (PS) on respiratory failure in lungs of rats. Methods Twenty Wistar rats were intraperitoneally anesthetized with pentobarbital sodium, and then inserted into the catheter via tracheotomy for artificial respiration. Peak inspiratory pressure (PIP) is set at 147 kPa and the breath ratio is 1: 1. Pulmonary perfusion (37 ℃ saline, 40ml · kg-1) for 8 ~ 10 times was performed on all animals after the PIP and PEEP were adjusted to 1 96kPa and 0 49kPa, respectively. When the arterial partial pressure of oxygen (PaO2) dropped below 12kPa, the animals were randomly divided into group A and group B, 10 in each group. Animals in group A were injected with 5 mg of pure PS 2 (0 5 ml) through the trachea and 5 mg (0 5 ml) of PS 2 containing 25 mg of ketamine in group B respectively. After 120min PEEP withdrawal, and PIP transferred to 147kPa. Results The PaO2 of all animals dropped from 5 9 4 kPa to about 10 3 kPa after lavage (P <0.05). After treatment, the PaO2 in both groups increased significantly to the pre-lavage level (563kPa) (P <0.05). After evacuation of PEEP, PaO2 in group A decreased significantly below 20 kPa (P <0 05) compared with that before lavage, whereas in group B the PaO2 remained above 46 kPa (P 0 05). By the end of the experiment, all animals in group B survived whereas only four in group A survived. Conclusions Pulmonary surfactant preparations containing ketamine can better maintain the respiratory function of rats with respiratory failure without PEEP under low airway pressure