摘要目的 了解儿童重症监护病房(PICU)机械通气患儿的代谢状态及分布情况,结合实际能量消耗值,评估营养供给情况.方法 以2013年11月至2014年4月入住首都医科大学附属北京儿童医院PICU内机械通气患儿为研究对象.入选标准:小儿危重病例评分＜90分或符合美国PICU入院标准;年龄＞29 d,＜18岁;机械通气治疗时间＞24h;机械通气潮气量＞60 ml.于机械通气15～24 h采用美国Med Graphic公司CCM/D能量代谢测定系统测量患儿的静息能量消耗值;运用Schofield-HTWT公式计算静息能量消耗的预测值,根据实测值与预测值的比值划分代谢状态;根据实际供给能量和所需摄入能量相比(测量的能量支出加10％)界定营养供给状态.将入选研究对象按照性别、年龄、不同疾病种类及营养供给状态进行分组,比较不同分组的代谢状态及不同代谢状态的营养供给情况.x2检验进行组间比较.结果 共有68例患儿纳入研究,其中男46例、女22例,男女比例2:1;包括肺炎合并呼吸衰竭25例,中枢神经系统疾病合并呼吸衰竭23例及手术后气管插管20例.共有36例患儿(53％)处于低代谢状态,23例(34％)处于高代谢状态,9例(13％)处于正常代谢状态.男性组高代谢状态占26％(12例),低代谢状态占57％(26例),正常代谢状态占17％(8例);女性组则高代谢状态为50％(11例),低代谢45％(10例),正常代谢5％(1例),不同性别间代谢状态的分布差异无统计学意义(x2=4.176,P=0.095).24例＜3岁患儿以高代谢为主占63％(15例),33例3～9岁及11例10～18岁患儿则均以低代谢为主(分别有19和10例);肺炎和中枢神经系统疾病合并呼吸衰竭患儿以低代谢为主,分别为60％ (15/25)和52％(12/23);而手术后患儿高代谢比率(55％,11/20)高于上述两种内科疾病.不同年龄、临床诊断的代谢状态分布差异有统计学意义(x2=6.152、P=0.013和x2=5.816、P=0.023).营养供给正常者31例(46％);营养供给不当者37例(54％),其中营养供给不足者共22例(32％),营养过剩者15例(22％);不同疾病种类和代谢状态下的营养供给情况差异无统计学意义(x2 =1.091,P=0.896).结论 机械通气患儿的代谢状态存在个体差异,以低代谢状态为主.年龄、疾病种类均可影响患儿的代谢状态分布.经验性营养支持不适用于患儿的个体化治疗.

abstractsObjective To determine the resting energy expenditure on mechanical ventilation in pediatric intensive care unit (PICU) by indirect calorimetry, and analyze the distribution of metabolic states.The nutrition supply was assessed according to the resting energy expenditure.Method An observational study which was held in PICU of Beijing Children's Hospital from November 2013 to April 2014.Critically ill children with mechanical ventilation were enrolled in this study.The inclusion criteria included the following: (1) pediatric critical illness score ＜ 90, or meet the United States PICU admission criteria;(2) age ＞29 days, ＜ 18 years old;(3) time of mechanical ventilation ＞24 hours;(4) volume of mechanical ventilation ＞ 60 ml.Resting energy expenditure was determined by US Med Graphic Company CCM/D energy metabolism test system.Predictive resting energy expenditure was calculated for each subject with age-appropriate equation (Schofield-HTWT).According to the actual energy intake records and required energy intake (10％ higher than the measured value) to define the nutritional status.The selected subjects were grouped according to gender, age, types of disease and nutritional status, and compared the metabolic status and nutritional supply of different groups.Result Sixty-eight children were enrolled in this study, 46 were boys and 22 were girls, including 25 cases of pneumonia with respiratory failure, 23 cases of central nervous system diseases complicated with respiratory failure and 20 cases of postoperative tracheal intubation.The ratio of boys and girls was 2: 1.The results showed 36 patients in a low metabolic state, accounting for 53％, 23 patients in a high metabolic state, accounting for 34％ and 9 patients (13％) in the metabolism of the normal state.In the male children, 12 cases (26％) were in the high metabolism and 26 cases (57％) were in the low metabolism, and 8 cases (17％) were in the normal metabolism.In the female children, 11 cases (50％) were classified into high metabolism;10 cases (45％) into low metabolism and 1 case (5％) was classified into normal metabolism.There was no significant difference in the distribution of metabolic status among different gender(x2 =4.176, P =0.095).In terms of ages, 15 cases (63％) were mainly in high metabolism in the patients at age ＜ 3 years, 19 and 11 patients in 3-9 and 10-18 years age group respectively are mostly in low metabolism.As to the diseases, pneumonia complicated with respiratory failure and central nervous system diseases complicated with respiratory failure with mechanical ventilation (respectively 15 cases (60％) and 12 cases (52％)) were in low metabolism mainly;11 cases of postoperative tracheal intubation were in high metabolism states, accounting for 55％.The distribution of metabolic status in different age and clinical diagnosis had significant difference.Thirtyone patients had normal nutrients supply, accounting for 46％, 37 patients had inappropriate nutrition supply, accounting for 54％, including insufficient supplies of nutrients in 22 cases, accounting for 32％,excessive supplies of nutrients were seen in 15 cases (22％).There were no statistically significant differences among the different types of diseases.Conclusion There are differences in the metabolic state of the mechanical ventilation in critically ill patients, mainly in low metabolic state.The age and types of diseases can affect the metabolic status of patients.Empirical nutritional support is not applicable to patients.