McCamish M A, Dean R E, Ouellette T R
JPEN J Parenter Enteral Nutr. 1981 Nov-Dec;5(6):513-6. doi: 10.1177/0148607181005006513.
This report documents a specific situation in which indirect calorimetry produced large overestimations of oxygen consumption and energy expenditure of a patient on a respirator. High positive-end expiratory pressures combined with high fractional concentrations of O2 led to perforation of lung parenchyma with considerable loss of O2, which produced subcutaneous emphysema and recurrent pneumothoraces. Typical calculations for determining energy expenditure from O2 consumption, therefore, could not be employed. Calculations utilizing the volume of CO2 expired, however, were less sensitive and variable during this time period. Resting energy expenditures were calculated from the volume of CO2 expired by using 5.52 kcal/l as the caloric equivalent of CO2. This procedure does not overestimate energy needs when a physiological gas leak exists (high positive-end expiratory pressures and high fractional concentrations of O2 or chest tube). This is very important in the ventilatory patient as excess carbohydrate can further stress the compromised pulmonary status.
本报告记录了一种特殊情况，即间接测热法对使用呼吸机的患者的耗氧量和能量消耗产生了大幅高估。高呼气末正压与高氧分数浓度相结合，导致肺实质穿孔，大量氧气流失，进而产生皮下气肿和复发性气胸。因此，无法采用通过耗氧量来确定能量消耗的典型计算方法。然而，在此期间，利用呼出二氧化碳量进行的计算敏感性较低且变化较大。静息能量消耗通过使用5.52千卡/升作为二氧化碳的热当量，根据呼出二氧化碳量来计算。当存在生理性气体泄漏（高呼气末正压、高氧分数浓度或胸管）时，此方法不会高估能量需求。这对于通气患者非常重要，因为过量的碳水化合物会进一步加重受损的肺部状况。
