Background: Patients with subarachnoid hemorrhage often have impaired consciousness and cannot regulate nutritional intakes themselves. Previous studies have demonstrated elevated energy expenditure in the acute phase, but it is not known whether the energy demand is constant during the first week after onset of the disease. In this study, we performed daily measurements of energy expenditure with indirect calorimetry during the first 7 days after aneurysmal subarachnoid hemorrhage in mechanically ventilated patients.

Methods: Metabolic measurements were performed daily with indirect calorimetry in 26 patients with aneurysmal subarachnoid hemorrhage. All patients were intubated and mechanically ventilated. The measured value was compared to the predicted values from the Harris–Benedict equation and the Penn State University 1998 equation. Urinary nitrogen excretion was measured daily.

Results: There was a significant increase in energy expenditure during days 2–3 compared to days 5–6. The Harris–Benedict equation underestimated metabolic demand. The Penn State 1998 equation was closer to the measured values, but still underestimated caloric need. Urinary nitrogen excretion increased throughout the first week from initially low values.

Conclusions: There is a dynamic course in energy expenditure in patients with aneurysmal subarachnoid hemorrhage, with increasing metabolic demand during the first week of the disease. Indirect calorimetry could be used more often to help provide an adequate amount of energy.

背景：蛛网膜下腔出血的患者经常意识障碍，无法自行调节营养摄入。先前的研究表明，急性期的能量消耗增加，但尚不清楚该病发作后第一周的能量需求是否恒定。在这项研究中，我们对机械通气患者在动脉瘤性蛛网膜下腔出血后的前7天内使用间接量热法进行了每日能量消耗的测量。

方法：每天用间接量热法对26例动脉瘤性蛛网膜下腔出血患者进行代谢测量。所有患者均经插管并机械通气。将测量值与Harris-Benedict方程和Penn State University 1998方程的预测值进行比较。每天测量尿中氮的排泄量。

结果：与第5-6天相比，第2-3天的能源消耗显着增加。哈里斯-本尼迪克特方程式低估了代谢需求。Penn State 1998方程更接近于测量值，但仍低估了热量需求。在整个第一周，尿液氮的排泄量从最初的低值开始增加。

结论：动脉瘤性蛛网膜下腔出血患者的能量消耗过程是动态的，在疾病的第一周内代谢需求增加。间接量热法可以更经常地用于帮助提供足够的能量。