Druml W, Fischer M, Ratheiser K
Medical Department III, Vienna General Hospital, University of Vienna, Austria.
JPEN J Parenter Enteral Nutr. 1998 Jul-Aug;22(4):217-23. doi: 10.1177/0148607198022004217.
Fat is the preferred energy fuel both in patients with sepsis and with hepatic failure. Thus lipid emulsions should serve as an ideal nutritional substrate in parenteral nutrition. However, previous studies have generated conflicting results on the utilization of artificial lipids in these disease states, and systematic studies in critically ill patients with combined organ dysfunctions and additional complications are lacking. We compared the elimination, hydrolysis, and oxidation of a 20% lipid emulsion in critically ill patients on respiratory support with sepsis and with sepsis plus hepatic failure and in healthy control subjects.
Medical critical care unit of a university hospital.
Eight critically ill patients with sepsis, 8 patients with sepsis and decompensated chronic hepatic failure, and 10 healthy volunteers were investigated. Elimination and hydrolysis was evaluated during constant i.v. infusion of 4.5 mg.kg body wt-1.min-1 of triglycerides during 120 minutes. Concentrations of plasma triglycerides, free fatty acids, and glycerol were measured, and elimination parameters were analyzed from plasma curves of triglycerides by using a two-compartment model. Resting energy expenditure and substrate oxidation were measured by indirect calorimetry.
In patients with sepsis without and with hepatic failure the rise in plasma triglycerides was blunted and the clearance of triglycerides was enhanced by 20% and 40% (p < .05), respectively, compared with healthy controls. Basal free fatty acid concentrations were elevated, and the rise of free fatty acids and glycerol was comparable to healthy subjects. Energy expenditure was increased and lipid oxidation (as fraction of total energy expenditure) was slightly elevated in both patient groups; the rise in lipid oxidation during lipid infusion was comparable to controls. No side effects or impairment of gas exchange was seen.
In a clinically relevant dosage range, the utilization of an i.v. lipid emulsion, the elimination and hydrolysis of triglycerides, and the lipid oxidation is not impaired in ventilated critically ill patients with sepsis or sepsis and chronic hepatic failure. Lipid emulsions thus are efficiently metabolized in critically ill patients with combined organ dysfunctions and associated sepsis.
脂肪是脓毒症患者和肝衰竭患者首选的能量燃料。因此，脂质乳剂应是肠外营养中理想的营养底物。然而，先前的研究在这些疾病状态下人工脂质的利用方面得出了相互矛盾的结果，并且缺乏对合并器官功能障碍及其他并发症的重症患者的系统性研究。我们比较了在接受呼吸支持的脓毒症患者、脓毒症合并肝衰竭患者以及健康对照受试者中20%脂质乳剂的清除、水解和氧化情况。
一所大学医院的医学重症监护病房。
对8例脓毒症重症患者、8例脓毒症合并失代偿性慢性肝衰竭患者以及10名健康志愿者进行了研究。在120分钟内以4.5mg·kg体重-1·min-1的速率持续静脉输注甘油三酯期间评估清除和水解情况。测量血浆甘油三酯、游离脂肪酸和甘油的浓度，并使用二室模型从甘油三酯的血浆曲线分析清除参数。通过间接测热法测量静息能量消耗和底物氧化。
与健康对照相比，脓毒症患者（无论有无肝衰竭）血浆甘油三酯的升高受到抑制，甘油三酯清除率分别提高了20%和40%（p < 0.05）。基础游离脂肪酸浓度升高，游离脂肪酸和甘油的升高与健康受试者相当。两组患者的能量消耗均增加，脂质氧化（占总能量消耗的比例）略有升高；脂质输注期间脂质氧化的升高与对照组相当。未观察到副作用或气体交换受损。
在临床相关剂量范围内，静脉输注脂质乳剂的利用、甘油三酯的清除和水解以及脂质氧化在通气的脓毒症或脓毒症合并慢性肝衰竭的重症患者中未受损害。因此，脂质乳剂在合并器官功能障碍及相关脓毒症的重症患者中能有效代谢。
