目的 探讨≤10 kg体重婴幼儿心脏直视术后呼吸机使用时间的相关因素。 方法 从2005年3月－2011年6月，选择纳入接受心脏直视手术的体重≤10 kg的先天性心脏病婴幼儿，分析各项围术期指标与术后呼吸机使用时间的关系，讨论该类婴幼儿术后呼吸机使用时间决策。 结果 共纳入体重≤10 kg的婴幼儿42例，呼吸机使用时间（42.74 ± 52.55） h，中位数20.88 h;发现术后2 h入量（mL/kg），术后4、8、16 h总入量（mL/kg）与术后呼吸机使用时间相关（P＜0.05），术后呼吸机使用时间与患儿ICU入住时间约成线性相关（P＜0.05）。 结论 影响低体重婴幼儿心脏直视术后呼吸机使用时间是术后液体管理，实施“限制性液体管理”治疗策略可能会促进患儿的术后快速康复。术后液体管理如何具体影响患儿呼吸机使用时间，影响患儿的预后，尚需进一步研究。Objective To evaluate the factors related to the postoperative mechanical ventilation (MV) duration in low-weight infants weighing less than 10 kg having undergone open cardiac surgery. Methods From March 2005 to June 2011, infants less than 10 kg undergoing congenital cardiac surgery were included in this research. We analyzed the relationship between various peri-operative indexes and the duration of MV, and discussed the decision for ventilation time for these infant patients. Results A total of 42 infants were included in our study. The ventilation time was (42.74 ±52.55) hours with a median of 20.88 hours. The postoperative second-hour fluid intake and the total intake of fluid at hour 4, 8, and 16 were related to the duration of mechanical ventilation (P＜0.05). And the ventilation time had a linear relationship with the ICU-stay time (P＜0.05). Conclusions The postoperative fluid management is associated with the duration of mechanical ventilation for low-weight infants having undergone open cardiac surgery. “Fluid controlling management” may facilitate quick recovery of the infant patients. However, as for how the fluid should be managed, how the fluid management influences ventilation time and the prognosis, more research is needed.