谷氨酰胺对大鼠烧伤后代谢率变化及相关激素分泌的影响

目的　探讨谷氨酰胺对大鼠烧伤后代谢率变化及相关激素分泌的影响。方法　采用 3 0 %体表面积Ⅲ度烧伤大鼠模型 ,将 88只Wistar大鼠随机分为烧伤对照 (B)组和谷氨酰胺 (GLN)组。两组大鼠采用等氮、等热卡的营养支持 ,GLN组予 1 0g/kg dGLN ,B组予等量的甘氨酸。观察了伤前及伤后 (PBD) 1、3、5、7、10d大鼠静息能量代谢率 (REE)的变化 ,检测了血中胰岛素、胰高血糖素及皮质醇的含量 ,并进行相关分析。结果　烧伤后两组大鼠的REE、血浆胰岛素、胰高血糖素和皮质醇含量均明显高于伤前。两组相比 ,GLN组的REE明显低于B组 ,血浆胰高血糖素和皮质醇略低于B组 ,胰岛素含量略高于B组 ,在PBD3～ 5存在显著差异。而胰岛素及胰岛素 /胰高血糖比值则明显高于B组 ,在PBD1～ 10存在显著差异 ( P <0 0 5 ,P <0 0 1)。相关分析显示 ,REE同胰岛素 /胰高血糖素比值呈显著负相关 (r=-0 78,P <0 0 5 )。结论　烧伤大鼠代谢率明显增高 ,服用谷氨酰胺能有效降低烧伤后高代谢反应 ,其机制与谷氨酰胺能促进合成激素分泌 ,降低分解激素释放有关     

不同营养支持途径对烧伤后肠源性高代谢的影响

目的:探讨不同营养支持途径对烧伤后肠源性高代谢的影响及其发生机制.方法:将88只大鼠随机分为烧伤后静脉营养支持(TPN)组和肠道营养支持(EN)组,观察伤前及伤后第1、3、5、7、10天大鼠静息能量代谢率(REE)的变化,同时检测血浆内毒素(LPS)、肿瘤坏死因子(TNF)和白细胞介素-1(IL-1)的含量.结果:烧伤后两组大鼠的REE、TNF、LPS和IL-1均明显高于伤前(P＜0.01),两组相比,EN组大鼠REE较TPN组明显降低,下降幅度为17%～20%,血浆TNF、LPS及IL-1水平也明显低于TPN组(P＜0.05或0.01).结论:肠道营养可降低烧伤大鼠肠道受损程度,降低炎症介质的释放,从而降低高代谢反应.     

烧伤后肠源性高代谢研究--高代谢及内毒素

目的 :探讨烧伤后高代谢与内毒素的关系。　方法 :观察了 4 0例严重烧伤病人 ,烧伤总面积达 (45±11.3) % ,其中深度烧伤为 (2 9.7± 10 .4 ) %。观察指标为静息能量消耗 (REE)、血浆内毒素、丙二醛 (MDA)、超氧化物歧化酶 (SOD)、肿瘤坏死因子 (TNF)、白细胞介素 8(IL 8)、高血糖素、皮质醇、血清二胺氧化酶 (DAO)及尿乳果糖 /甘露醇比值 (L/M)、尿儿茶酚胺。　结果 :①烧伤后 1～ 14天观察期间 ,REE与血浆内毒素、TNF、IL 8、高血糖素呈显著相关 (r分别为 0 .5 985、0 .92 36、0 .8381、0 .85 17,P分别为 0 .0 14 3、0 .0 0 11、0 .0 0 94、0 .0 0 73) ;血清DAO与血浆SOD呈显著负相关 (r=- 0 .7871,P =0 .0 2 0 4 ) ,尿L/M与血浆SOD、MDA亦呈显著相关 (r =- 0 .9114、0 .94 4 5 ,P=0 .0 0 16、0 .0 0 0 4 )。②复苏期后 (伤后 4～ 14天 ) ,REE与SOD呈显著负相关 (r=- 0 .7180 ,P <0 .0 5 )。　结论 :烧伤后高代谢与内毒素、TNF、IL 8、高血糖素有关 ,伤后肠道损伤与早期缺血 再灌注损伤有关 ,血内毒素增高可能与肠道损伤所致的肠道内毒素移位有关。     

早期肠内喂养MCT/LCT改善烧伤病人高代谢的临床研究

目的　通过比较烧伤病人早期肠内喂养含MCT/LCT与只含LCT的肠内营养制剂对烧伤后高代谢的不同影响 ,探讨MCT/LCT改善烧伤后代谢状态的作用及可能机制。方法　选取 3 0例TBSA >3 0 %的烧伤病人 ,并随机分为两组 ,一为Fresubin75 0MCT组 (F组 ) ,即饲以含MCT/LCT的肠内营养制剂Fresubin 75 0MCT ;另一组为Nutrison组 (N组 ) ,即饲以只含LCT的肠内营养制剂Nutrison。于伤后 2 4h内进行完全肠内营养支持 ,共支持 10d。在PBD1、4、7、10分别观察了两组患者影响代谢的严重因子的变化情况 (包括血浆胰岛素、胰高血糖素、肿瘤坏死因子 (TNF)及皮质醇。尿 3 -甲基组氨酸排泄率 )。结果　烧伤后机体分解代谢增加 ,两组相比血浆皮质醇水平无显著差异 ;F组患者血浆胰岛素与胰高血糖素浓度的比值明显升高 ,尿 3 -甲基组氨酸排泄率及血浆TNF明显下降。结论　含MCT/LCT的肠内营养制剂较只含LCT者 ,能促进烧伤后机体合成激素的分泌 ,减少肌肉蛋白分解排出量 ,从而改善烧伤病人代谢状况 ,并有利于提高全身营养及免疫状况 ,促进创面愈合     

谷氨酰胺对烧伤后大鼠肠道损伤及炎症反应的影响

目的探讨谷氨酰胺对烧伤后大鼠肠道损伤及炎症反应的影响.方法采用30%体表面积Ⅲ°烧伤大鼠模型,将88只Wistar大鼠随机分为烧伤对照组和烧伤后补充谷氨酰胺(GLN)组.两组大鼠采用等氮、等热量的营养支持,GLN组每天给予1.0 g/kg GLN,对照组给予等量的甘氨酸.观察烧伤前及烧伤后第1、3、5、7、10天大鼠静息能量消耗(REE)的变化,同时检测烧伤后血浆二胺氧化酶(DAO)活性及内毒素(LPS)、肿瘤坏死因子(TNF)和白细胞介素-1(IL-1)的含量.结果烧伤后两组大鼠的REE、DAO、TNF、LPS和IL-1均明显高于烧伤前(P＜0.01),GLN组REE、血浆DAO活性及TNF、LPS和IL-1含量均明显低于对照组(P＜0.05,P＜0.01).结论口服GLN能减轻烧伤后肠道受损程度,降低烧伤大鼠血中炎症介质水平,从而降低伤后机体高代谢反应.     

大豆蛋白对大鼠血脂调节的作用机制

目的 探讨大豆蛋白对大鼠血脂代谢的影响及其可能的作用机制.方法 SPF级雄性SD大鼠48只,进食基础饲料适应性喂养2周,随机分为4组:大豆蛋白组,酪蛋白组,大豆蛋白高脂组,酪蛋白高脂组.进食实验饲料28d.测定试验蛋白中氨基酸含量,大鼠血清中血脂、胰岛素和胰高血糖素水平.结果 与酪蛋白相比,大豆蛋白的赖/精比值小,蛋氨酸含量低,胱氨酸含量高.大豆蛋白组大鼠TC、HDL-C浓度及TC/HDL-C比值比酪蛋白组低.大豆蛋白高脂组大鼠血清TC、TG、LDL-C浓度及TC/HDL-C比值比酪蛋白高脂组低.大豆蛋白组大鼠血清胰岛素浓度比酪蛋白组低.大豆蛋白高脂组大鼠血清胰岛素浓度比酪蛋白高脂组低,胰高血糖素浓度比酪蛋白高脂组高.结论 大豆蛋白可通过影响血清中胰岛素/胰高血糖素比率及其氨基酸种类和含量来调节血脂水平,其作用机制还需进一步探讨.     

早期肠内营养对严重烧伤病人血浆激素和脂类调节因子的调节作用

旨在研究早期肠内营养能否降低烧伤后与代谢有关的血浆激素和脂类调节因子前列腺素 E2 (PGE2 )、血栓素 B2(TXB2 )水平的影响。将 2 2例年龄在 18～ 49岁 ,烧伤面积在30 %～ 85 %的严重烧伤病人随机分为早期肠内营养组(EEN)和延迟肠内营养组 (DEN ) ,每组 11例 ,用间接测热法每天监测静息能量消耗 (REE)。据此提供每天所需营养物质 ,分别于伤后 0、4、8、12天监测血清儿茶酚胺 (CA) ,皮质醇 (Cortisol) ,胰高血糖素 (Glucagon) ,胰岛素 (Insulin) ,PGE2 ,TXB2 水平。结果 :EEN组血 CA,Cortisol,Glucagon,PGE2 、TXB2 伤后 …     

早期肠道喂养改善烧伤后肠道血液灌流的实验研究

探讨早期肠道喂养改善烧伤大鼠肠道血液灌流的机制。采用 30 % TBSA 度烧伤大鼠模型 ,分为正常对照 (C)、单纯烧伤 (B)和早期喂养 (EF)组。分别检测伤前及伤后 3、6、12、2 4、48h肠组织中内皮素 (ET)、一氧化氮 (NO)、血管活性肠肽 (VIP)含量及肠粘膜血流量 (IMBF)。结果 :烧伤后肠组织中 ET、NO、VIP及 ET/ NO、ET/ VIP比值均呈上升趋势 ,而IMBF则显著低于伤前。 EF组中 ET含量及 ET/ NO、ET/VIP比值明显低于 B组 ,而 NO、VIP及 IMBF则高于 B组 ,ET/ NO、ET/ VIP同 IMBF呈显著负相关 (r1 =- 0 .95 ,P<0 .0…     

膝关节微创外科围手术期应激反应

目的分析膝关节微创外科围手术期创伤应激反应的激素水平、C-反应蛋白(CRP)和机体能量代谢的变化。方法膝关节半月板损伤病人16例,交叉韧带损伤病人26例,均为闭合性损伤。分为A组22例膝关节关节镜微创外科手术,B组20例切开关节直视下手术。两组患者于手术前1d,手术后1d和手术后3d早晨分别抽取空腹静脉血离体后检测胰岛素、生长激素、皮质醇、CRP。同时测定静息能量消耗(REE)和呼吸商(RQ)。结果胰岛素在B组患者手术后第3天与术前比较有明显下降。生长激素、皮质醇、CRP术后上升在B组明显高于A组(P<0.05)。两组患者静息REE术后较术前显著增加,而术后B组患者REE明显高于A组(P<0.05)。两组患者RQ术后较术前均有显著下降。结论膝关节关节镜微创外科手术创伤小,应激水平低,对患者代谢影响小,有利于机体应激激素、氮平衡和能量代谢的恢复。     

失血性休克后早期肠道喂养效果的实验研究

目的：研究大鼠失血性休克后早期肠道喂养对胃肠结构与功能、应激与代谢相关的激素、全身营养状况的影响。方法：随机将72只大鼠分为假休克组（SS组）、休克组（HS组）、早期肠道喂养组（HSE组）。SS组自由进食，HSE组复苏后1h用安素营养液喂养，HS组用等量等渗盐水喂养。选择复苏后2、6、24、48h四个时相点观察体重，肝功能，血浆皮质醇，胰高血糖素、胰岛素水平、肝、小肠、胃组织形态学变化。结果：与HS组相比，HSE组体重、血浆总蛋白及白蛋白、肝及腌肠肌含氮量等营养指标明显改善，肝功能改善，血浆皮质醇、胰高血糖素水平降低，胰岛素水平增高，胃肠粘膜病变减轻。结论：HS后早期肠道喂养有助于保护内脏功能，降低应激与高代谢反应，改善全身营养状况。     

严重烧伤早期营养支持途径对机体代谢的影响

目的：前瞻性观察两种营养支持途径对严重烧伤病人代谢的影响。方法：临床烧伤病人１９例,随机分为早期肠道营养组（ＥＮ）和胃肠外营养组（ＰＮ）。有严重吸入伤,休克,消化道出血,明显腹泻及腹部疾患者不列入本研究。除行常规抗休克等处理外,ＥＮ组伤后第１天即口服或经鼻饲管注入奥力康,ＰＮ组从静脉补充氨基酸,脂肪乳剂和葡萄糖等,两组热量和氮摄入基本相等。     

Prevention of nosocomial infection in a pediatric intensive care unit (PICU) through the use of selective digestive decontamination

Objective: To assess the effectiveness of selective digestive decontamination (SDD) on the control of nosocomial infection (NI) in critically ill pediatric patients. Design: A prospective, randomized, non-blinded and controlled clinical microbiology study. Setting: The pediatric intensive care unit (PICU) of a tertiary level pediatric university hospital. Criteria for inclusion: Patients 1 month to 14 years old, who underwent some kind of manipulation or instrumentation (mechanical ventilation, vascular cannulation, monitoring of intracranial pressure, thoracic or abdominal drainage, bladder catheterization, peritoneal dialysis, etc.) and/or presented a neurological coma requiring a stay in the PICU of 3 or more days. Patients: Over a period of 2 years, 244 patients met the inclusion criteria; 18 patients were withdrawn because of protocol violation. The treatment group comprised 116 patients and the control group, 110 patients. Intervention: The treatment group received a triple therapy of colimycin, tobramycin and nystatin administered orally or via nasogastric tube every 6 hours. All patients with mechanical ventilation or immune-depression received decontamination treatment of the oropharyngeal cavity with hexitidine (Oraldine® 0.5 mg/ml) every 6–8 hours in accordance with the PICU's conventional protocol. Method: Up to 10 types of nosocomial infection were diagnosed following criteria of the Centers for Disease Control (CDC). The severity and manipulation of the patients on admission was assessed using the therapeutic intervention scoring system (TISS) and multi-organ system failure scores (MOSF). Measurements and main results. Univariant analysis: SDD did not significantly reduce the incidence of NI, antibiotic use, the length of stay, or mortality; although a small percentage of respiratory and urinary tract infections was detected, catheter-related bacteremia was the most common infection. Multivariant analysis: Controlling the risk factors for each child through log regression showed that SDD acted as a protective factor for more than 90% of the sample with respect to the appearance of respiratory and urinary tract infections, reducing the risk of such infections to 1/5 and 1/3, respectively. Conclusions: SDD was effective in controlling respiratory and urinary tract infections in children admitted to the PICU, but it did not reduce the incidence of other types of nosocomial infection.     

Epidemiology of Pseudomonas aeruginosa in an intensive care unit using selective decontamination of the digestive tract.

Selective decontamination of the digestive tract (SDD) aims to reduce the rate of nosocomial infections in critical care patients. Pseudomonas spp. are common nosocomial pathogens and in this study isolates collected from patients and the environment during an SDD trial were examined. The study enrolled 161 SDD cases and 170 controls. Pseudomonads were isolated from 27% of SDD patients and 30% of controls. SDD partially suppressed colonization in the 'gastro-respiratory' mucosae but not in the rectum. A total of 108 isolates of pseudomonads were recovered from the environment. Resistance in rectal isolates was minimal but isolates from 'gastro-respiratory' sites showed increasing aminoglycoside resistance. Eighty-six per cent of aminoglycoside-resistant isolates from both patient groups and environment were pyocine type 1x. Episodes of infection were reduced in the SDD patients (6) compared with the controls (16), aminoglycoside-resistant strains being associated with zero episodes in SDD patients but with five in the control group.     

Selective decontamination of the digestive tract in intensive care.

Nosocomial infection in intensive care unit (ICU) practice is a common problem and is associated with abnormal carriage of Gram-negative aerobic bacilli in the gastrointestinal tract, resulting in endogenous infections. Selective decontamination of the digestive tract (SDD) is a regimen aimed at preventing or eradicating this abnormal carriage. A large number of trials examining SDD in ICU practice have been published, the vast majority showing a significant reduction in the incidence of nosocomial, Gram-negative infection. However, the impact on morbidity and mortality is much less certain. A recent meta-analysis has suggested a 10-20% reduction in mortality (3-6% absolute difference) with SDD. A discussion of these results is presented together with potential criticisms of SDD.     

Antibiotic resistance associated with selective decontamination of the digestive tract.

Selective decontamination of the digestive tract (SDD) appears to reduce infection, particularly pneumonia, in intensive care, and some patients benefit markedly. Gram-positive overgrowth and antibiotic resistance in both Gram-positive and Gram-negative organisms has been recorded. However, the clinical and epidemiological significance of these observations is still debated. Future studies will need to be of sufficient size and duration to provide good quality data on which the safety and efficacy of SDD can be properly judged.     

Energy expenditure in patients with multiple organ failure

We measured the level of resting energy expenditure (BEE) and its evolution in patients with multiple organ failure (MOF). We studied 30 patients requiring mechanical ventilation and sedation. REE was measured by means of a closed circuit method on days 1-5, 7, 10 and 14 after initiating the protocol. REE values between 115% and 145% of the REE calculated from the Harris-Benedict's formula were considered as moderate hypermetabolism and values above 145% as severe hypermetabolism. A predictive formula for determining caloric requirements was developed and validated in another 25 MOF patients. In the study group, 25 patients presented moderate hypermetabolism (83%) and two severe hypermetabolism(7%). Mean REE in the whole group was stable but individual patients may have had a large variability in REE. The anthropometric variables, body temperature and reason for admission predicted the REE with a coefficient of determination of 0.73, according to the model: REE= -3295 + 105.5S - 8A + 11.7 W + 7.7 H + 93.2 T + 123.1 Tr - 145.6 Su where: S = sex (male = 1, female = 0); A: age in years; W: weight in Kg; H: height in cm; T: temperature in degrees C; Tr: trauma (Tr = 1); Su: surgical (Su = 1). The reliability of the model, taken from the validation group, showed that the shrinkage was 0.8%. In conclusion, when MOF patients are sedated they present moderate hypermetabolism. Day-to-day variability of REE in the individual patients and the large variability in estimating REE with our formula preclude its clinical utility and we recommend to measure REE in MOF patients.     

Selective decontamination of the digestive tract (SDD) in intensive care patients: a critical evaluation of the clinical, bacteriological and epidemiological benefits.

Twenty trials (17 controlled and three observational cohort studies) on selective decontamination of the digestive tract (SDD) have been undertaken to date. SDD is defined as a technique which aims to eradicate carriage of disease-causing microorganisms by means of lethal oropharyngeal and faecal antimicrobial concentrations. The SDD concept and the criteria for the choice of the antimicrobials used in the SDD programme are explained. Abolition of the carrier state is thought to provide clinical, bacteriological and epidemiological benefits. Infection-specific morbidity and mortality, emergence of antibiotic resistance and outbreaks are the main endpoints evaluated in this review. Of the 15 controlled studies that considered carriage, 14 demonstrated a significant reduction of Gram-negative bacillary (GNB) carriage. Severe infections, including pneumonia and septicaemia, caused by enterobacteria and pseudomonads have been virtually eliminated in these trials. Five of the 12 centres that evaluated mortality showed a significant decrease among patients who received SDD. Two recent trials describe the control of an outbreak with a multiresistant Klebsiella by SDD. There are three indications for the use of SDD so far: (i) in trauma patients; (ii) in certain elective surgical procedures including liver transplantation and oesophageal resection; and (iii) in control of outbreaks of ICU infection. Future lines of research may include a properly designed trial with mortality as endpoint and studies on the transfer of SDD from the ICU into the ward as part of prophylaxis in major surgery.     

Investigation of the immune status of mice during and following selective decontamination of the digestive tract

Selective decontamination of the digestive tract (SDD) employs oral antibiotics to eliminate aerobic Gram-negative bacilli while retaining the anaerobic flora. A combination of SDD and parenteral cefotaxime has recently been reported to strikingly reduce the incidence of infection in patients treated in an intensive therapy unit. The present study describes the effects of SDD and of cefotaxime on the immune response of mice to protein antigens. The in vivo cellular response to ovalbumin and sheep red blood cells was unchanged. However, SDD appeared to decrease the in vitro mitogenic response of spleen cells to phytohaemagglutinin, and cefotaxime similarly affected the response to Concanavalin A. The antibody response to sheep red blood cells was increased in the period after discontinuation of SDD. The antibody response was otherwise not affected. These results indicate that SDD is unlikely to have adverse effects on the immune response to protein antigens.     

Gut decontamination of critically ill patients reduces Helicobacter pylori acquisition by intensive care nurses

The prevalence of Helicobacter pylori is increased in healthcare workers and in intensive care nurses. Exposure to H. pylori from gastric secretions and faeces are probably the main sources of transmission to healthcare workers. Routine use of selective decontamination of digestive tract (SDD) in an intensive care unit suppresses H. pylori in critically ill patients. It was questioned whether this suppression and the subsequent decreased exposure to H. pylori for intensive care nurses would lead to a lower prevalence of H. pylori infection. Helicobacter pylori infection prevalence in intensive care nurses from a unit routinely using SDD (group I) was compared to that of nurses from a unit not using SDD (group II). Heathcare workers from other departments of the hospital where no SDD was used (group III) served as a control group. Persons using proton pump inhibitors were excluded. Helicobacter pylori was detected by Laser Assisted Ratio Analyser(13)C-urea breath test (UBT) and serology. This could not be performed in three out of 64 in group I, five out of 55 in group II and five out of 55 in group III (total UBTs = 169). The prevalence of H. pylori infection was 11% (7/61) in group I and 25.5% (14/50) in group II (P= 0.027). In group III, the prevalence of H. pylori infection was 16% (8/45), which was not significantly different from both group I and II. Sero-prevalence in group I was 18.6%, 27% in group II (ns) and 24% in group III. Mean age in the three groups was 35.9, 37.8 and 36.6 years, respectively (ns). In conclusion, the prevalence of H. pylori infection among intensive care nurses is lower in nurses from a unit using SDD compared to a non SDD-using unit. Acquisition of H. pylori by transmission from critically ill patients appears to be diminished through SDD use.