Dispensable and indispensable amino acid requirements in depleted patients receiving total parenteral nutrition

Fifty depleted patients (15% ideal body weight loss) were treated at two different non protein kcal (35 and 50) levels with three different amino acid solutions, while receiving a standard daily nitrogen (N) intake of 0.19 gN/kg. Six groups were studied including one in which 50 kcal were administered with a mixed lipid and glucose system. Daily N balance and amino acid profile, were determined for 5 days in low kcal groups and 10 days in the high kcal groups. Positive N balance was obtained at only low kcal intake with two of the three solutions. Judging from pooled data, N balance was related to phenilalanine (Phe) and Methionine (Met) intake and a minimum intake of 91 mg/kg Phe and 70 mg/kg Met seemed necessary to obtain positive N balance. Increasing kcal reduced Phe and Met needs allowing positive N balance with lower intake. A lower then normal baseline amino acid level was observed for nearly all amino acid [except Isoleucine (Ile) Phe, Met, Lysine (Lys) and Ornitine (Orn)]. During treatment plasma concentration of administered amino acids increased in relation to the administered amount for Valine (Val), Ile, The, Met, Lys, Threonine (Thr), Arginine (Arg), Glycine (Gly), (p < 0.001) Alanine (Ala) (p < 0.025) and Proline (Pro) (P < 0.05). A significant negative correlation with administered kcal was found for Ile, Met, Lys and Arg. Amino acids not administered did not show an homogeneous pattern and, using multiple regression, the variables affecting single amino acid behaviour were identified.     

Thermogenic response to total parenteral nutrition in depleted patients with multiple organ failure

Nutrient-induced thermogenesis was studied in eight patients with severe nutritional depletion and multiple organ failure after abdominal surgery. Energy expenditure (EE) and RQ were recorded continuously over a period of 4 days. On each study day balanced total parenteral nutrition was administered during a period of approximately 16 h, followed by a period of low-energy glucose infusion. The total energy supply was in the order of 110% of the measured EE and the supply of glucose, fat and amino-acids was 2.6 +/- 0.4, 2.6 +/- 0.2 and 0.84 +/- 0.2 kJ x kg BW(-1) x h(-1) (mean +/- SD), respectively. The nutrient-induced thermogenesis, expressed as the rise in EE in percent of the energy content of the administered nutrients, was approximately 5%, which appears to be lower than previously observed in healthy individuals. A plateau in energy expenditure was reached after 6-8 h in response to parenteral nutrition. It is hypothesized that this plateau reflects the oxidative capacity and thus may be used as a guideline for nutritional therapy.     

Visual function in patients undergoing long-term total parenteral nutrition

To evaluate the effects of long-term total parenteral nutrition (TPN) on eye function, 27 adults and 12 children in the UCLA Home TPN Clinic underwent ophthalmoscopic examination and visual-function testing. Direct inspection of the fundus showed a marked granularity of the retinal pigmented epithelium in some patients. About one-half of the children and one-third of the adults tested had at least one and usually two abnormalities in their electroretinogram. Determination of blood nutrients thought to affect vision revealed that zinc and vitamin E were within normal range. Vitamin A concentrations were above normal in 10 of 19 adults and selenium concentrations were below normal in 10 of 10 children and 17 of 21 adults tested. Linoleic and linolenic acid concentrations were low; plasma, platelet, and urine taurine concentrations were significantly lower than normal. Despite these diffuse nutrient abnormalities, only zinc and vitamin E concentrations correlated significantly with any index of visual function.     

早期全肠外营养及肠内、外混合营养对神经外科危重患者免疫功能的影响

目的探讨早期给予全肠外营养（TPN）及肠内营养（EN）、肠外营养（PN）混合支持对神经外科危重患者免疫功能的影响。方法采用前瞻性对照研究将神经外科危重患者按入院顺序随机分为TPN组及EN＋PN组,并对比营养支持前后两组CD3、CD4、CD8、CD4／CD8、CD3／CD25、IgA、IgG、IgM、血清白蛋白的变化。结果给予神经外科危重患者两种营养支持均可提高其CD3、CD4、CD8及CD3＋／CD25＋比值（P〈0．05,P〈0．01）;两种营养支持方式均可显著升高IgA、IgG、IgM、（P〈0．05）及血清白蛋白浓度（P〈0．01）。与TPN组比较,EN＋PN组CD3、CD4、CD8、CD4／CD8比值、IgA、IgG、IgM浓度及血清白蛋白水平均显著升高（P〈0．05,P〈0．01）。结论早期TPN及EN＋PN支持均可促进神经外科危重患者免疫功能的恢复及提高,EN＋PN的作用优于TPN,对于神经外科危重患者应早期给予营养支持治疗。     

Treatment effects of parenteral vitamins in total parenteral nutrition patients

To determine the prevalence of abnormal vitamin levels in an adult hospitalized population requiring total parenteral nutrition (TPN) and to assess the effect of routine parenteral vitamin therapy on vitamin levels, we studied 35 general surgical patients. Assays for 12 vitamins were performed both before and after a standard 10-day course of TPN. Patients were given nothing by mouth. The first 25 patients received a daily parenteral vitamin mixture tailored to the recommendations of the Nutrition Advisory Group of The American Medical Association (maintenance dose). The final 10 patients were given a parenteral multivitamin dose providing substantially greater amounts of most vitamins (repletion dose). Only 58% (190/324) of pre-TPN vitamin levels were normal, 25% were low, and 17% were high. No patient had fewer than two abnormal baseline levels. Vitamin levels did not correlate with serum albumin, body weight, or nitrogen balance. After 10 days of treatment, only 39% of low pre-TPN vitamin levels improved; most (45/62) of the low posttreatment levels were low at baseline. The higher repletion dose resulted in a significantly (p less than 0.01) greater percent increase in vitamin A, C, and pyridoxine levels. The prevalence of abnormal vitamin levels in this population is high (42%). Standard parenteral vitamin therapy leads to marginal improvement in abnormally low pre-TPN vitamin levels.     

Hypermanganesemia in patients receiving total parenteral nutrition

BACKGROUND: Manganese is one of the trace elements that is routinely administered to total parenteral nutrition (TPN) patients. The recommended daily IV dosage ranges from 100 to 800 MICROg. We have used 500 microg daily. Recent reports have suggested neurologic symptoms seen in some patients receiving home parenteral nutrition (HPN) may be due to hypermanganesemia. Therefore, HPN patients and some short-term inpatients receiving TPN were studied to ascertain the relationship between dose and blood levels. METHODS: Red blood cell manganese levels were obtained by atomic absorptiometry. RESULTS: The levels in 36 hospitalized, short-term patients obtained within 48 hours of initiating TPN were all normal. The 30 patients receiving TPN from 3 to 30 days had levels that ranged from 4.8 to 28 microg/L (normal, 11 to 23 microg/L). Two patients had abnormal levels, at days 14 and 18. Fifteen of the 21 patients receiving inpatient TPN or HPN for 36 to 5075 days had elevated Mn levels. Only one patient with hypermanganesemia, an inpatient, had abnormal biochemical liver tests (bilirubin and alkaline phosphatase). One of the patients with a high level had some vestibular symptoms attributed to aminoglycoside use and had increased signal density in the globus pallidus on T1-weighted images on magnetic resonance imaging (MRI). A second patient with Mn levels twice normal had no neurologic symptoms, but had similar MRI findings. A third had some basal ganglia symptoms, confirmed by a neurologic evaluation, seizures, and very high Mn levels. The MRI showed no signal enhancement, but motion artifacts limited the study technically. CONCLUSIONS: Hypermanganesemia is seen in HPN patients receiving 500 microg manganese daily and may have resulted in some neurologic damage in three patients. Hypermanganesemia is sometimes seen after a short course of TPN in inpatients, as early as 14 days. Patients should be monitored for hypermanganesemia if they receive Mn in their TPN for >30 days. A 500 microg/d dose of Mn is probably excessive, and 100 microg/d should probably never be exceeded. Mn should be eliminated from the solution if the Mn level is elevated and should not be readministered unless the level returns to normal or subnormal. Mn should not be supplemented if the patient has liver disease with an elevated bilirubin.     

Hypocupremia in patients receiving total parenteral nutrition

Although hypocupremia is a well-known consequence of long-term total parenteral nutrition (TPN), its incidence as well as the duration of TPN necessary to induce it are still unsettled. The purpose of this study is to review the changes in serum copper level in 25 patients receiving TPN for a period longer than 2 wk (mean duration 6 wk) at the Istituto Nazionale Tumori of Milan and to evaluate the possible relationship of cupremia with the basic disease. Main indications for TPN included enterocutaneous fistulas (11 patients), cancer cachexia (10 patients), radiation enteropathy (two patients), and severe postoperative stricture following esophagogastric resection (two patients). Mean value of serum copper at the beginning of the study was 143 micrograms/100 ml (normal value 65-165 micrograms/100 ml), and the regression analysis showed a mean fall of 5.64 micrograms/100 ml/wk. Hypocupremia occurred in four patients (three with intestinal fistulas and one with radiation obstructive enteritis) at 5th, 6th, 9th, and 6th wk of TPN, respectively. No patient with cancer cachexia developed hypocupremia. No patient with hypocupremia had clinical evidence of a copper deficiency syndrome. We conclude that 1) hypocupremia does not occur within the first month of TPN; 2) its incidence is about 16% in patients intravenously fed for period longer than 2 wk; 3) it is more frequent in patients with enterocutaneous fistulas, whereas it never occurs in patients with cancer cachexia, and 4) it is not necessarily associated to a clinicometabolic syndrome of copper deficiency. Finally, the "nutritional" meaning of serum copper should be questioned in cancer patients since it could represent a "tumor marker."     

术前精氨酸强化PN对结直肠癌病人免疫功能的影响

目的：探讨术前精氨酸强化肠外营养（ＰＮ）对结直肠癌病人免疫功能的影响。 方法：选择经病理证实的结直肠癌病人作为研究对象,术前随机分为三组,即对照组给常规术前准备,常规ＰＮ组和精氨酸强化ＰＮ组除常规准备外,分别给予常规ＰＮ和精氨酸强化ＰＮ７天,术前７天和手术当天早晨７：００采集外周静脉血,测定ＣＤ３、ＣＤ４、ＣＤ８、ＩＬ－２、ＮＫ细胞和ＮＫ细胞活性;取同期进行腹股沟疝手术的病人作为正常对照。 结果：     

Energy requirements for cancer patients and the effect of total parenteral nutrition

Limited data are available concerning resting metabolic expenditure (RME) in cancer patients and the effect of RME by varying glucose intake. This study describes the measurements on 21 patients with colorectal cancer while fasting and with incremental levels of standard TPN-glucose system by central vein. Following an overnight fast, the measured mean +/- SEM percent difference from the predicted RME for the male group was 4.13 +/- 1.67% and the female group, 2.09 +/- 2.09%. The overall mean percent difference of 2.95 +/- 1.45 suggests that colorectal cancer does not cause an increase in energy expenditure. Hepatic metastases in 11 of the patients did not influence RME. The data from the 21 patients indicate a statistically significant increase in RME with TPN compared to postabsorptive states in females of 37%, in males 21.88%, and combined of 29.88%. Progressively greater increases in RME were seen when calories provided incrementally exceeded the basal RME. Carbohydrate loading in excess of the patient's calorie need, as indicated by the respiratory quotient (RQ) greater than 1.0, results in fat synthesis and other energy-costing processes. The basal RME demonstrates that these cancer patients are not hypercatabolic, but do respond to high-level force-feeding with markedly increased metabolic expenditures.     

The effect of total parenteral nutrition on hepatic drug oxidation

Hepatic dysfunction is a frequent complication of total parenteral nutrition (TPN), indicated by derangement of standard liver function tests. However, such changes are variable and nonspecific, and represent hepatic injury rather than changes in hepatic function. Antipyrine (Phenazone) clearance is a sensitive indicator of hepatic microsomal enzyme activity and provides a more specific indication of hepatic function. This was used to investigate the effect of different TPN regimens. Patients receiving a postoperative 2000 kcal TPN regimen providing all nonprotein calories as dextrose (n = 16) showed a 34% reduction of mean antipyrine clearance after 7 days of TPN compared to controls (n = 13, p less than 0.05). This effect was seen also in patients receiving a 1600 kcal dextrose-based regimen (n = 8). In patients receiving a 2000 kcal TPN regimen in which 500 kcal were provided as lipid (n = 10), mean antipyrine clearance was not significantly different from that of the control group. This study indicates the sensitivity of hepatic microsomal oxidative function, an important route of drug metabolism, to different TPN regimens.     

全肠外营养支持对危重病人免疫功能的影响

目的 :探讨全肠外营养支持对重症监护病房 (ICU)病人免疫功能的影响。　方法 :6 0例危重病人分为A、B两组 ,A组用常规治疗 ,B组在常规治疗的基础上 ,加用静脉营养支持治疗 2周。　结果 :治疗后B组T细胞亚群、淋巴细胞总数显著高于A组 (P <0 .0 1 ) ;OT试验显著改变 ,IgG、IgA、IgM无明显变化 (P >0 .0 5 )。　结论 :提示营养支持治疗可以明显改善危重病人的免疫功能     

The effect of preoperative total parenteral nutrition on surgery outcomes

The effect of preoperative total parenteral nutrition (TPN) on morbidity and mortality was studied in medical records of discharged surgical patients. Patients were classified into two groups on the basis of their ability to meet established criteria for malnutrition and the use of preoperative or postoperative TPN. The control group consisted of 44 patients who received TPN only after surgery or for less than 5 days preoperatively. The experimental group consisted of 26 patients who received treatment for at least 5 days before surgery and/or after surgery. Nutrition parameters measured included serum albumin, total lymphocyte count, hemoglobin, weight, and percent weight loss. Major septic complications (MSC) considered were intra-abdominal sepsis, wound dehiscence, septicemia, and pneumonia. Other complications included respiratory failure, congestive heart failure, fistulas, urinary tract infection, shock, and death. The experimental group showed improvements after surgery in the nutritional parameters listed and had a lower incidence of morbidity and mortality. Deficits in serum albumin, total lymphocyte count, and weight losses greater than or equal to 10% have been significantly (p less than .01) linked to the incidence of MSC. MSC also has been more frequently noted among patients who did not have TPN prior to surgery and who died following surgery. Therefore, preoperative TPN does appear to make a difference in the outcome of surgery.     

Utilization of D-methionine during total parenteral nutrition in postsurgical patients.

Utilization of intravenously administered D-methionine was measured by morbidly obese subjects fed parenterally after elective gastric bypass surgery. Five patients were infused with a 25% glucose--4.25% amino acid solution containing DL-methionine, and four were treated with a 25% glucose--3.5% amino acid solution containing only L-methionine. Mean (+/- SD) total daily methionine excretion was 0.06 +/- 0.04 mmoles (of 28 +/- 4 mmoles infused) in patients treated with the L-methionine containing solution, and was 15.2 +/- 4.2 mmoles/day (of 45.2 +/- 5 mmoles DL-isomer infused) in patients treated with the DL-methionine containing solution. In these latter patients, 90 to 98% of the excreted methionine was the D-isomer. The data indicate 64 +/- 23% of infused D-methionine is excreted in the urine. Four patients excreted between 70 to 85% of infused D-methionine in the urine, but one patient excreted only 35 to 55%, suggesting better utilization. Plasma methionine levels were higher (9.9 +/- 1.9 mumoles/100 ml) in patients infused with solutions containing DL-methionine than those infused with the L-methionine solution (4.5 +/- 1.0 mumoles/100 ml). In the former case, 49% of plasma methionine was the D-isomer. The data indicate poor D-methionine utilization by postsurgical patients during total parenteral nutrition when given as DL-methionine in the presence of other amino acids and glucose.     

Clinical effect of nonthrombotic total parenteral nutrition catheters

Radiographic evidence of subclavian vein thrombosis has been shown to occur in 33% of total parenteral nutrition patients. This incidence can be significantly reduced to 8% when heparin is administered concomitantly in total parenteral nutrition solutions. To evaluate the thrombotic risk of a newly developed polyurethane catheter, 20 concurrent patient pairs were prospectively cannulated with either a standard polyethylene catheter plus heparin or a polyurethane catheter without heparin in a sequential statistical study. Radionuclide venograms (Tc99m) were performed within 72 hr of catheterization, at biweeky intervals, and at termination of total parenteral nutrition administration. No patient in either group developed clinical (pain, arm swelling, collateral veins) or venogram evidence of thrombosis after catheterization during an overall cannulation period of 820 days. Use of polyurethane catheters and elimination of heparin in total parenteral solutions may be particularly important since contraindications to heparin use are common. Additionally, heparin elimination can decrease admixture work and confusion (ie, subcutaneous heparin double dosing) without increasing the risk of subclavian vein thrombosis.     

Serum lipoproteins in home total parenteral nutrition patients

Patients maintained in our home total parenteral nutrition (HTPN) program receive very small amounts of cholesterol in their solutions. Because of the severe intestinal insufficiency which is characteristic of this group, they do not absorb significant amounts of cholesterol or bile salts from their intestines. We investigated the serum lipoproteins in nine patients maintained on HTPN for 36 +/- 4 (mean +/- SEM) months. Fat emulsions were given twice a week as a source of essential fatty acids. Mean serum cholesterol 110 +/- 6.5 mg/dl, LDL-cholesterol 75 +/- 6 mg/dl, and HDL-cholesterol 29 +/- 1 mg/dl, were at or below the 5th percentile compared with age- and sex-matched Lipid Research Clinic controls. HDL-cholesterol to serum cholesterol ratio was in the normal range (0.25 +/- 0.30). The mean serum cholesterol did not rise, but the mean serum triglyceride rose significantly from 72 +/- 4 to 104 +/- 16 mg/dl (p less than 0.05) immediately after completion of TPN infusions with fat emulsions. There was a negative correlation between the length of HTPN therapy and the total serum cholesterol (r = 0.43, p less than 0.05). Thus, HTPN patients have markedly depressed concentrations of total serum cholesterol, LDL-cholesterol, and HDL-cholesterol, but the ratio of HDL cholesterol to total serum cholesterol is in the normal range.     

Abnormal liver function in malnourished patients receiving total parenteral nutrition: a prospective randomized study.

A prospective study was performed in clinically malnourished patients in which liver function was tested during a 4-week period of total parenteral nutrition (TPN). The purpose was to determine if concomitant intravenous lipid administration would reduce liver function abnormalities noted to occur frequently in patients receiving TPN. Twenty-five patients were randomly assigned to receive either daily infusions of 200 cc of a 20% lipid emulsion with TPN or TPN without lipid for the first week. In the subsequent 3 weeks all patients received daily intravenous lipid. The early lipid treatment group received 0.7 g lipid/kg BW/day and approximately 280 mg of choline/day from the lecithin emulsifier throughout the entire study period. Liver function tests were performed twice in the first week, then weekly thereafter. There were significant (p less than 0.05) elevations in liver function tests in the early lipid treatment group (for aspartate aminotransferase in weeks 1, 2, and 3, and lactic acid dehydrogenase in weeks 2 and 3). Alkaline phosphatase activity was elevated at weeks 2, 3, and 4 for the lipid-treatment group and at week 1 for the lipid-restricted group. The two groups had a similar elevation in gamma-glutamyltransferase activity. Analysis of covariance demonstrated that the overall duration of TPN, and not the presence or absence of intravenous lipid, was significantly related to the elevations in both alkaline phosphatase and gamma-glutamyltransferase (GGT) levels. In contrast, the early intravenous administration of lipid was significantly related to the increase in aspartate aminotransferase levels. The peak increase in AST was noted at day 7 in the lipid-administration group.(ABSTRACT TRUNCATED AT 250 WORDS)