Overview of randomized clinical trials of total parenteral nutrition for malnourished surgical patients

The past decade has seen a maturation of the art and science of perioperative nutritional support. We now have sufficient data to make informed and reasonable judgments regarding when we should and should not provide perioperative TPN. These judgments can be considered medically sound and fiscally responsible. The following guidelines are proposed: (1) Postoperative TPN should be considered when oral or enteral feeding is not anticipated within 7 to 10 days in previously well-nourished patients or within 5 to 7 days in previously malnourished or critically ill patients. (2) Preoperative TPN should be considered in patients who cannot or should not eat or receive enteral feedings if the operation must be delayed for more than 3 to 5 days. (3) Preoperative TPN should be considered in the most severely malnourished surgical candidates if an operative delay is not contraindicated. In patients with only mild to moderate degrees of malnutrition preoperative TPN is not indicated.En el último decenio se registra la maduración del arte y la ciencia del soporte nutricional perioperatorio. Ya disponemos de suficiente información para tomar decisiones razonables sobre cuándo debemos o no debemos proveer nutrición parenteral total (NPT) preoperatoria. Tales decisiones pueden ser ahora lógicas desde el punto de vista médico, y responsables desde la perspectiva económica.El propósito del presente artículo es la revisión de los estudios sobre la valoración de los informes disponibles para una mejor definición de la NPT en el periodo preoperatorio. El papel más apropiado de la NPT en el periodo preoperatorio probablemente está ubicado entre los extremos representados, por una parte, por el entusiasmo desbordado de los finales de los años 1970, y por otra, el cauteloso escepticismo que prevaleció una década más tarde. El objetivo del soporte nutricional perioperatorio es mantener o mejorar el estado nutricional durante los días inmediatamente anteriores o posteriores a la operación. Pero la NPT perioperatoria sólo se puede justificar si evidencia reducción de las complicaciones y muerte postoperatorias. En general, los hallazgos positivos en un número limitado de los ensayos publicados que sugieren beneficio de la NPT no proveen documentación convincente sobre su eficacia, pero por otra parte tampoco excluyen posibles beneficios de importancia por razón de defectos en el diseño de los estudios. Recientes estudios, a partir de 1987, indican que no hay beneficio en pacientes con grados mínimos de malnutrición, proveen evidencia fuerte en contra de eficacia clínica en pacientes con grados leves o moderados de malnutrición y sugieren, aunque no confirman, su eficacia en los pacientes serveramente desnutridos. En ausencia de una malnutrición severa, o de otras indicaciones específicas para NPT preoperatoria, la mayoría de los pacientes deben ser operados con prontitud.     

Comparison between glucose and a combination of glucose, fructose, and xylitol as carbohydrates for total parenteral nutrition of surgical intensive care patients.

The effects of four day periods of infusions of 600 gm/24 hours glucose and 600 gm/24 hours of a combination of glucose, fructose, and xylitol were compared. This study was performed during total parenteral nutrition of twelve postoperative patients with major complications. The mean plasma glucose level was significantly lower during the infusion of the combination of sugars (154.2+/-19.5 mg/100 ml versus 193.9+/-15.0 mg/100 ml[p is less than 0.005). Furthermore, the required dosage of exogenous insulin was significantly lower (18.9+/-12.3 units/day versus 43.7+/-19.7 units/day [p is less than 0.01). Mean renal carbohydrate losses were 0.85 per cent during glucose infusion and 1.7 per cent during infusion of the combination. The influence of both infusion regimes on values for pH, base excess, lactate, pyruvate, free fatty acids, insulin, sodium, potassium, chloride, magnesium, phosphorus, bilirubin, alkaline phosphatase, SGOT, and SGPT 0.85 has been investigated. No clinical side effects were observed. It is concluded that the administration of the investigated combination of glucose, fructose, and xylitol is justified in patients in whom hyperglycemia during infusion of glucose alone is difficult to control with insulin.     

围手术期肠外肠内营养支持

外科手术所致的代谢改变和生理创伤会使患者营养状况恶化,对于术前已有营养不良的患者,情况会更严重.营养不良会导致心、肺、肾、胃肠道等器官功能受损,降低机体免疫和肌肉收缩的功能,患者容易出现感染性并发症.营养不良还会导致伤口愈合延迟,活动受限,手术恢复和住院时间延长,再入院几率升高,医疗费用显著增加.诸多循证医学证据表明,营养不良会影响外科患者的临床结局,成为重症、大手术死亡的重要因素.虽然广大外科同仁对营养支持的重要性已有一定认识,临床应用也已较为普遍,但不规范、欠合理的应用(尤其是肠外营养)仍是临床上常见的问题.     

谷氨酰胺并肠外营养支持在外科术后危重患者中的应用

目的 观察谷氨酰胺并肠外营养支持在外科术后危重患者中的应用价值.方法 外科术后危重患者50例,随机分为观察组和对照组,每组各25例.两组患者均于术后第1天行肠外营养支持,观察组在对照组的基础上加用加丙氨酰-谷氨酰胺20 9(商品名:力太注射液,华瑞制药).治疗后检测两组患者营养指标、免疫指标.结果 观察组治疗第7天营养指标及免疫指标均较对照组明显改善.结论 加用谷氨酰胺的肠外营养支持能明显改善外科术后危重患者的营养状况及免疫功能.     

Preoperative parenteral nutrition of malnourished surgical patients

Malnutrition is associated with increased incidence of surgical complications and mortality. The efficacy of preoperative parenteral nutrition in preventing septic states and mortality was evaluated in malnourished patients undergoing gastrointestinal surgery. The patients were allocated to three groups according to criteria of malnourishment. In all groups parenteral nutrition decreased the incidence of septic complications and serious sepsis as compared with control patients.     

重症急性胰腺炎早期肠内营养和肠外营养疗效的荟萃分析

目的为明确早期肠内营养(EN)和全胃肠外营养(TPN)对重症急性胰腺炎(SAP)患者的疗效,对相关文献进行荟萃分析。方法检索1970年1月—2009年6月发表的有关早期EN和TPN治疗SAP的临床随机对照试验的文献。按入选标准,有7项临床试验纳入研究范围,由2名评价者对入选研究中有关试验设计、研究对象的特征、研究结果等内容独立进行摘录,并用RevMan5.0.18软件进行分析。结果早期EN与TPN比较,前者能显著降低胰腺感染发生率(OR=0.38,95%CI:0.18~0.82,P=0.01)及器官衰竭发生率(OR=0.43,95%CI:0.23~0.79,P=0.007),减少手术干预(OR=0.34,95%CI:0.18~0.63,P=0.0006)及病死率(OR=0.41,95%CI:0.19~0.88,P=0.02)。但总的感染率两者差异无统计学意义[OR=0.43,95%CI(0.17,1.10),P=0.08]。结论SAP患者早期EN比TPN更为安全有利。     

Preoperative total parenteral nutrition and surgical outcome in patients with inflammatory bowel disease

Further trials are needed to identify the preoperative patient who will have a significantly improved postoperative outcome with the use of total parenteral nutrition. Better nutritional markers are needed to evaluate the response to total parenteral nutrition and to help identify the irreducible minimum that should be given. In our series, patients who received preoperative total parenteral nutrition for at least 5 days had significantly fewer postoperative complications (p < 0.05) than those who did not. All patients with postoperative complications had either a preoperative serum albumin level less than 3.5 g/dl or a serum transferrin level less than 150 mg/dl. Preoperative total parenteral nutrition for at least 5 days is strongly recommended in patients with inflammatory bowel disease who have severe protein depletion.     

Glutamine-supplemented total parenteral nutrition enhances T-lymphocyte response in surgical patients undergoing colorectal resection.

OBJECTIVE: The authors determined the effect of glutamine-supplementation of TPN on postoperative peripheral blood T-cell response and proinflammatory cytokine production in patients undergoing colorectal resection. SUMMARY BACKGROUND DATA: Several vital tissues, including the immune system, are very dependent on glutamine; however, this amino acid, which may be essential in conditions of stress, only now is becoming formulated suitably for incorporation into TPN. The effects of such supplementation on the immune function of stressed surgical patients is unknown. METHODS: Patients (n = 20) were randomized to receive conventional TPN (0.2 g nitrogen/kg/d) or an isonitrogenous/isocaloric regimen with 0.18 g of glutamine/kg/d from days 1 to 6 postoperatively. T-cell DNA synthesis and interleukin (IL)-2 production and peripheral blood mononuclear cell IL-6 and tumor necrosis factor (TNF) production were measured in vitro preoperatively and on days 1 and 6 postoperatively. RESULTS: T-cell DNA synthesis after 5 days of TPN was increased compared with preoperative values in the glutamine-supplemented group (median preoperative tritiated thymidine uptake: 78.3 x 10(3) cpm, day 6: 95.0 x 10(3) cpm, p < 0.05). There was no such increase in the control TPN group (preoperative: 89.0 x 10(3) cpm, day 6: 69.4 x 10(3) cpm, p > 0.05). Glutamine supplementation did not influence IL-2 production or the production of TNF or IL-6. CONCLUSIONS: Glutamine supplementation may be a method of enhancing T-cell function in the surgical patient receiving TPN.     

Total enteral nutrition versus total parenteral nutrition after major torso injury: attenuation of hepatic protein reprioritization

Reprioritization of hepatic protein synthesis, a process involving accelerated production of acute-phase proteins at the expense of constitutive proteins, accompanies major trauma. The impact of isocaloric, isonitrogenous total enteral nutrition (TEN) versus total parenteral nutrition (TPN) on hepatic reprioritization was investigated in a prospective, randomized trial. Of the 59 patients with an abdominal trauma index (ATI) greater than 15 but not more than 40, 45 evaluable patients were followed. Results from 36 (18 TEN, 18 TPN) evaluable patients revealed that mean serum levels of acute-phase proteins increased, whereas mean serum levels increased to a greater extent in the TPN group. The maximal increase from baseline for the acute-phase response in both groups occurred at postinjury day 5 and was significantly higher for alpha 1-antitrypsin (alpha 1AT, p = 0.03) and orosomucoid (p = 0.02) in the TPN group. Nonacute-phase proteins reached a nadir at day 10 in the TPN group and increased in the TEN group; significant differences between TEN and TPN groups appeared for albumin (p = 0.004) and retinol-binding protein (RBP, p = 0.03); alpha 2-macroglobulin (alpha 2M) approached significance at day 10 (p = 0.07). When change from baseline values was compared, day 10 increases in alpha 2M were significantly higher (p = 0.04) in the TEN group. These data suggest that postinjury TEN attenuates reprioritization of hepatic protein synthesis in patients sustaining major trauma.     

Glucose intolerance in critically ill surgical patients: relationship to total parenteral nutrition and severity of illness.

The authors evaluated the relative influence of severity of illness and total parenteral nutrition (TPN) on glucose intolerance in critically ill surgical patients. Records of TPN administration, serum glucose measurements, and the simplified acute physiology score (SAPS) were extracted from the surgical intensive care unit (SICU) and hospital clinical information systems (CIS) for all patients admitted to the SICU from October 1, 1989 through March 31, 1990. Critical hyperglycemia was defined as glucose > 400 mg/dL and critical hypoglycemia as < 40 mg/dL. During the study period, 1,129 patients received 3,054 days of care, including 88 patients who received 705 days of TPN. Of 4,985 glucose determinations performed during the study period, 48 (0.96%) were critically abnormal. Critical hyperglycemia occurred in 1.7 per cent of blood samples from TPN patients, compared to 0.7 per cent in non-TPN patients (P < 0.005). However, the mean admission and daily and maximum severity of illness scores were significantly higher in TPN patients compared to non-TPN patients (all P < 0.0005). Mean glucose levels rose with increasing SAPS in both TPN and non-TPN patients. When stratified by severity of illness, TPN patients did not have significantly higher glucose levels than non-TPN patients except for the SAPS = 15 category. The authors conclude that the glucose intolerance noted in critically ill TPN patients reflects their underlying severity of illness rather than TPN administration per se.     

老年术后患者全静脉营养治疗中预防心力衰竭的输液管理

目的探讨老年患者术后全静脉营养治疗过程出现急性心力衰竭的预防护理措施与效果。方法将65岁以上术后静脉营养治疗的患者460例,按住院时间顺序分为常规组(240例)和干预组(220例)。常规组给予输液管调节器控制输液速度(40~65gtt/min)、监测CVP并准确记录24h出入液量及输液常规健康教育;干预组在此基础上采取使用输液泵、阶梯式输液速度控制、合理安排输液次序、制定昼夜输液要求、缩短CVP监测间隔时间等措施。结果常规组出现急性心力衰竭8例(3.3%),干预组未发生,两组比较,差异有统计学意义(P0.05)。结论老年患者术后全静脉营养治疗过程中,采取积极的护理干预措施,可有效预防静脉输液诱发的心力衰竭。     

Metabolic intervention in surgical patients: the effect of alpha- or beta-blockade on glucose and protein metabolism in surgical patients receiving total parenteral nutrition

We performed a series of isotopic studies on the role of alpha- or beta-adrenergic activity in the regulation of glucose and protein metabolism in a group of surgical patients receiving total parenteral nutrition. We quantitated rates of glucose turnover and net protein breakdown by the primed constant infusion of 3H-glucose and 14C-urea, respectively. Basal measurements were first performed, and then the effect of either alpha- or beta-adrenergic blockade was assessed by means of the constant infusion of either phentolamine or propranolol. In addition, we assessed the effect of beta-stimulation by infusing the beta-agonist, salbutamol. The institution of alpha-adrenergic blockade did not significantly alter either the plasma glucose level or the rate of glucose production. However, the rate of net protein catabolism decreased significantly after alpha-adrenergic blockade. Before alpha-blockade the value for NPC was 0.88 +/- 0.27 gm/kg/day, and after alpha-blockade the corresponding value was 0.73 +/- 0.24 gm/kg/day (p less than 0.01). beta-Adrenergic blockade resulted in a decrease in the rate of glucose appearance from 38.2 +/- 6.1 mumol/kg/min to 35.1 +/- 5.7 mumol/kg/min, and the plasma glucose clearance increased from 5.0 +/- 0.8 ml/kg/min to 5.4 +/- 0.8 ml/kg/min. As a result of these changes the plasma glucose concentration decreased significantly (p less than 0.01) from 7.4 +/- 0.3 mumol/ml to 6.5 +/- 0.5 mumol/ml. beta-Adrenergic blockade did not significantly decrease the rate of net protein catabolism. beta-Stimulation with salbutamol resulted in a significant increase (p less than 0.05) in the rate of glucose production from 31.3 +/- 4.2 mumol/kg/min to 38.0 +/- 6.5 mumol/kg/min, and as a result the plasma glucose level increased significantly from 6.7 +/- 0.6 mumol/ml to 7.4 +/- 0.6 mumol/ml (p less than 0.04). We conclude from these studies that the role of the adrenergic nervous system in the promotion of endogenous glucose turnover in surgical patients receiving total parenteral nutrition is primarily a beta-adrenergic effect, whereas the promotion of protein catabolism is mainly an alpha-adrenergic effect.     

Sepsis from triple- vs single-lumen catheters during total parenteral nutrition in surgical or critically ill patients

We prospectively studied the infection rates for 59 triple-lumen (TLC) and 68 single-lumen (SLC) subclavian catheters during the administration of total parenteral nutrition (TPN) to surgical or critically ill patients. A standard protocol was used for catheter insertion and maintenance. The infection control committee determined independently whether patients had catheter-related sepsis, an infected insertion site only, or no catheter infection. The TLCs had an increased incidence of catheter sepsis (19%) compared with the SLCs (3%). Low rates (5% for TLCs and 3% for SLCs) of infected catheter sites only indicated that the catheter care was comparable for both groups. The patients in the two groups were similar but not identical; those with TLCs appeared to be sicker and, therefore, at greater risk to develop catheter sepsis than patients with SLC. However, since TLCs were involved in six times more catheter sepsis than were SLCs, limiting the use of a subclavian catheter to giving TPN only and strict adherence to a TPN protocol are necessary to minimize the risk of catheter sepsis.     

严重多发性创伤胃肠外营养的疗效分析

作者分析了４７例严重多发性创伤伤员（ＩＳＳ≥１６）全胃肠外营养（ＴＰＮ）的治疗效果。随机选择了４７例严重多发伤伤员，ＩＳＳ平均２０．１６。经过１周以上的中心静脉的正规ＴＰＮ治疗后，末梢血淋巴细胞计数，血浆白蛋白水平提高（ｔ检验Ｐ＜０．０５）。另外设对照非ＴＰＮ组６６例，ＩＳＳ平均２０．５０。具有同等的创伤严重程度，ＩＳＳ评分与ＴＰＮ组相比无差异（Ｐ＞０．０５）。两组病例均对原发创伤进行了积极的治疗，而对照组无ＴＰＮ治疗。疗效对比如下：ＴＰＮ与非ＴＰＮ组病死率之比为２．１３％比１３．６７％（Ｘ２＝４．５８，Ｐ＜０．０５）差异有统计学意义。结果表明：ＴＰＮ是严重多发性创伤重要的有效支持治疗措施。     

Postoperative total parenteral nutrition with fat emulsion for patients with esophageal varices

The administration of fat emulsion and total parenteral nutrition (TPN) was evaluated in 68 patients with liver disorders who underwent surgical treatment for esophageal varices. The subjects were divided into two groups, fat group (28 cases) and non-fat group (40 cases) according to with or without the administration of fat emulsion during the period of postoperative TPN. The results of liver function tests, blood glucose levels, intravenous fat tolerance tests, serum lipid levels, fatty acid composition in serum total lipids, nitrogen balances and body weight changes during the period of postoperative TPN were compared between both groups. Conclusions as follows; 1. The administration of fat emulsion during the period of postoperative TPN did not worsen the results of liver function tests, and relatively low levels of blood glucose were retained. 2. The removal rates of fat emulsion from the blood (K2 values) during the period of postoperative TPN were significantly higher than in those preoperative period, and changes in serum lipid level revealed no tendency toward retention of fat emulsion administered intravenously. 3. Cumulative nitrogen balance were almost similar in both groups. 4. The administration of fat emulsion the period of during postoperative TPN corrected the abnormalities of fatty acid composition in serum total lipid. Further, it was suggested that approximately more than 5 ml/kg/day of 10% fat emulsion would be advisable to prevent the decrease of linoleic acid. 5. These results suggested that the administration of fat emulsion was useful for the patients with esophageal varices during the period of postoperative TPN.