Aksnes A K, Brundin T, Hjeltnes N, Wahren J
Sunnaas Hospital, Nesoddtangen, Norway.
Clin Physiol. 1995 Jul;15(4):377-96. doi: 10.1111/j.1475-097x.1995.tb00528.x.
Metabolic, circulatory and thermal effects of intravenously (i.v.) administered amino acids were studied in eight patients with complete cervical spinal cord injuries, and compared with the effects in eight healthy subjects. Using indirect calorimetry and catheter techniques, whole-body and splanchnic oxygen consumption, blood flow and blood temperatures were measured before and at timed intervals during 2.5 h of i.v. infusion of 600 kJ of a mixture of 19 amino acids. Pulmonary oxygen uptake increased from 209 +/- 11 to 267 +/- 13 ml min-1 in the patients and from 268 +/- 5 to 320 +/- 8 ml min-1 in the controls. The thermic effect of amino acids was 21 +/- 3% and 16 +/- 2% in patients and controls, respectively. In both groups the splanchnic tissues accounted for approximately half of the rise in whole-body oxygen consumption. Cardiac output rose by, on average, 0.5 +/- 0.1 and 0.8 +/- 0.2 1 min-1 in patients and controls, respectively, while the hepatic blood flow remained unchanged in both groups. Pulmonary arterial blood temperature increased by 0.647 +/- 0.100 degrees C in the patients and by 0.244 +/- 0.174 degrees C in the controls (P < 0.05). The whole-body specific heat was low in the patients, its calculated maximum value being approximately 20% below the normal level. During the amino acid infusion the arterial blood concentration of amino acids rose by approximately 170% and 112% of its basal levels in patients and controls, respectively, indicating a significantly reduced capacity for cellular uptake of amino acids in tetraplegic patients. It is concluded that, in tetraplegic patients, i.v. infused amino acids induce prompt thermogenesis of normal magnitude accompanied by supranormal temperatures and amino acid concentrations in the blood, and that low whole-body specific heat contributes to the well-known thermoregulatory instability in tetraplegia.
对8例完全性颈脊髓损伤患者静脉注射氨基酸后的代谢、循环和热效应进行了研究，并与8名健康受试者的效应进行了比较。采用间接测热法和导管技术，在静脉输注600kJ 19种氨基酸混合物的2.5小时内，于输注前及定时测量全身和内脏的耗氧量、血流量及体温。患者的肺摄氧量从209±11ml/min增加至267±13ml/min，对照组从268±5ml/min增加至320±8ml/min。氨基酸的热效应在患者和对照组中分别为21±3%和16±2%。两组中，内脏组织约占全身耗氧量增加量的一半。患者的心输出量平均增加0.5±0.1L/min，对照组增加0.8±0.2L/min，而两组的肝血流量均无变化。患者的肺动脉血温度升高0.647±0.100℃，对照组升高0.244±0.174℃（P<0.05）。患者的全身比热较低，其计算最大值比正常水平低约20%。在输注氨基酸期间，患者和对照组动脉血中氨基酸浓度分别比基础水平升高约170%和112%，表明四肢瘫痪患者细胞摄取氨基酸的能力显著降低。结论是，在四肢瘫痪患者中，静脉输注氨基酸可迅速诱导正常幅度的产热，同时伴有体温过高和血液中氨基酸浓度升高，且全身比热较低导致了四肢瘫痪患者众所周知的体温调节不稳定。
