目的探讨早产儿机械通气不同呼气末正压(PEEP)水平对心功能的影响。方法40例早产儿均采用SIMV或IMV模式通气,根据PEEP水平将其分为低PEEP组(PEEP≤3cmH2O)和中PEEP组(PEEP>3cmH2O),应用彩色多普勒超声心动图检测两组早产儿的心脏泵血功能指标及各瓣口流速指标,比较两组间心功能指标的差异。结果低PEEP组左室泵血功能明显较中PEEP组高(P<0·01);低PEEP组肺动脉瓣口峰值流速明显高于中PEEP组(P<0·01),而主动脉瓣口峰值流速差异无统计学意义;低PEEP组二、三尖瓣E峰值均高于中PEEP组(P<0·01),但A峰值间差异无统计学意义,且前者二、三尖瓣E/A值均较后者高(P<0·05)。结论机械通气中PEEP主要影响左室泵血功能、全心舒张功能、肺动脉瓣口峰值流速及二、三尖瓣E峰值。 Objective To investigate the effect of different positive end expiratory pressure (PEEP) of mechanical ventilation on cardiac function in premature infants. Methods Forty infants with premature infants were ventilated by SIMV or IMV. According to the level of PEEP, they were divided into low PEEP group (PEEP≤3cmH2O) and middle PEEP group (PEEP> 3cmH2O). Color doppler echocardiography was used to detect premature infants Children’s heart pump blood function index and each valve orifice flow rate index, the difference between the two groups cardiac function index. Results The left ventricular pumping function in low PEEP group was significantly higher than that in middle PEEP group (P <0.01). The peak pulmonary flow velocity in PEEP group was significantly higher than that in middle PEEP group (P <0.01) There was no significant difference in the peak velocity between the two groups. The peak E and tricuspid E ​​in low PEEP group were higher than those in middle PEEP group (P <0.01), but there was no significant difference between peak A and peak A / A values ​​were higher than the latter (P <0 · 05). Conclusions PEEP in mechanical ventilation mainly affects left ventricular pumping function, diastolic function, peak pulmonary flow velocity and tricuspid E ​​peak.