间接测热法与传统能量估算法测定重症监护病房患者能量消耗的比较

摘要

目的 比较间接测热法测定能量消耗值(MEE)与传统方法得到估计能量消耗值(EEE)的差异,为危重患者的能量补充提供依据.方法 采用自身前后对照研究方法,对57例重症监护病房(ICU)患者使用间接测热法得到MEE,使用传统能量估算法如HB公式法、HB系数法和体重法得到EEE,其中低体重者[体质指数(BMI)<18.4 kg/m2]使用理想体重表计算,并以EEE与MEE的比值来评价估算能量的准确性.结果 HB公式法、HB系数法和实际体重法得到的EEE与间接测热法得到MEE比较差异均有统计学意义[(6335±1004)kJ、(9125±1795)kJ、(7188±1029)kJ比(7753±1439)kJ,P<0.05或P<0.01].HB系数法与实际体重法比较差异也有统计学意义(P<0.01),且后者的结果更接近实际测定值.用HB公式法估计能量会造成多数患者营养不足[低体重者占100%(4/4);体重正常者(BMI 18.5～23.9 kg/m2)占73.59%(39/53)].低体重者使用理想体重估算能量均能在营养充足范围内[100%(4/4)];体重正常者使用HB系数法和实际体重法可造成大量的营养不足[分别占39.62%(21/53)和43.39%(23/53)]及营养过度(分别占24.53%(13/53)和13.22%(7/53)].结论 对于危重病患者,各种传统公式估算能量消耗都很不精确,容易造成大量的营养不足和营养过度,最好使用间接测热法测定目标能量;在没有间接能量测定仪的情况下,低体重者使用理想体重,而体重正常者使用实际体重的估算法似乎较为合理.%Objective To compare measurement of energy expenditure(MEE)by indirect calorimetry (IC)with traditional estimation of energy expenditure(EEE),to provide a basis for energy supplementary for critically ill patients.Methods Using self-controlled study,the energy expenditure of 57 intensive care nnit(ICU)patients was measured by IC.Meanwhile,EEE was also calculated using the following equations:Harris-Benedict(HB),HB×factor,or 104.6 kJ/kg.Body weight were calculated using actual body weight(ABW)or ideal body weight(IBW).If body mass index(BMI)<18.4 kg/m2 it was considered as underweight,and the IBW was selected from the IBW table.The potential adequacy of estimated energy was assayed by ratio of EEE/MEE.Results There was significant difference in MEE by IC and EEE by HB,HB×factor and 104.6 kJ/kg [(6335±1004)kJ,(9125±1795)kJ,(7188±1029)kJ vs.(7753±1439)kJ,P<0.05 or P<0.01].There was significant difference between EEE by HB × factor and 104.6 kJ/kg(P<0.01),and EEE by 104.6 kJ/kg×ABW,and the latter was closer to MEE.Underfeeding would occur in most ICU patients if HB equation was used [100%(4/4)in underweight patients and 73.59%(39/53)in normal weight(BMI 18.5-23.9 kg/m2)].EEE as calculated by 104.6 kJ/kg ×IBW was reasonable in the underweight patients 100%(4/4),but EEE in the patients with normal weight by using HB×factor or 104.6 kJ/kg × ABW resulted in significant underfeeding[39.62%(21/53)and 43.39%(23/53)]or overfeeding[24.53%(13/53)and 13.22%(7/53)].Conclusion EEE derived from the equations was extremely inaccurate and may result in significant underfeeding or overfeeding in individuals.On the basis of this study we would recommend IC for measuring energy expenditure in ICU patients.Otherwise,the equations of 104.6 kJ/kg × IBW in underweight and 104.6 kJ/kg × ABW in normal weight patients may be reasonable.