Nineteenth Century Medical Guide

Chapter 364 360. Paris Expo

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([-]) Evaluation of gastrointestinal function during enteral nutrition therapy
During enteral nutrition, the enteral nutrition tolerance score table [70] (Table 4) can be used to assess the patient's feeding tolerance.

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胃肠功能评估：（1）胃肠功能正常：0分；（2）胃肠功能轻度损害：1~2分；（3）胃肠功能中度损害：3~4分；（4）胃肠功能重度损害：5分及以上。

When feeding intolerance occurs during enteral nutrition, it is necessary to evaluate the patient's enteral nutrition tolerance score every 6-8 hours, and adjust enteral nutrition infusion according to the score results: (1) Score increases ≤1 point: continue enteral nutrition and increase the rate; (1) score increased by 2 to 2 points: continue enteral nutrition, maintain the original rate or slow down the rate, and treat symptomatically; (3) score increased by ≥3 points or the total score ≥4 points: Suspend enteral nutrition and deal with it accordingly

Recommendation 26: The Enteral Nutrition Tolerance Scale is recommended as a tool for assessing patients' gastrointestinal tolerance.

[IV. Parenteral nutrition therapy for critically ill patients in neurosurgery]

([-]) When to initiate parenteral nutrition therapy
Enteral nutrition in critically ill neurological patients is affected by many factors, and sometimes it is difficult to achieve nutritional goals.When enteral nutrition cannot achieve nutritional goals, supplementing parenteral nutrition is not controversial if the patient is in a state of chronic nutritional deficiency.However, the optimal timing of parenteral nutrition supplementation is controversial.

It has been suggested that, after 3 days of ICU admission, when the energy level provided by enteral nutrition cannot reach 60%, supplemental parenteral nutrition should be initiated to reach the maximum energy requirement of 100% (indirect calorimetry).However, the EPaNIC study [71] observed that early parenteral nutrition was associated with prolonged ICU stay and mechanical ventilation time, increased infection rates and the need for renal replacement therapy.These findings may be related to overdosing energy by setting energy targets based on predictive formulas rather than indirect calorimetry.Reveals the potential harm of giving full, possibly overestimated, energy targets in critically ill patients during the acute phase.However, it is unclear whether setting targets using indirect calorimetry would have resulted in different outcomes in the study, and the optimal time point for initiating supplemental parenteral nutrition with the goal of achieving full caloric requirements is uncertain.

ASPEN/SCCM recommends that supplemental parenteral nutrition should be considered after 60–7 days if >10% of energy and protein requirements cannot be met through enteral route alone.This recommendation is based on an assessment that supplementation of parenteral nutrition with enteral nutrition before 7–10 days after ICU admission does not improve clinical outcomes and may even have deleterious consequences.However, there are currently no data to support initiation of parenteral nutrition after day 8, or to compare the effect of initiation of parenteral nutrition between days 4-7 versus days 8-10.

推荐建议27：在最大化的肠内营养策略下仍不能达到营养目标（间接测热法为80% EE，预测公式法为60%）的神经外科重症患者，7~10 d后可考虑启动肠外营养。不建议提前启动肠外营养治疗。

([-]) Selection of preparations for parenteral nutrition therapy
Parenteral nutrition is an important part of nutrition therapy, and the configuration of its nutrient solution has been widely concerned.Premixed parenteral nutrition and compound parenteral nutrition are two main types of parenteral nutrition, and the advantages and disadvantages of the two have attracted extensive attention from clinicians.Premixed parenteral nutrition minimizes compound errors and improves safety; compound parenteral nutrition can realize individualized treatment according to the actual situation of patients.

1. Comparison of compound parenteral nutrition and premixed parenteral nutrition formula: Both compound parenteral nutrition and premixed parenteral nutrition can basically meet the nutritional needs of patients.The heat-to-nitrogen ratio and glycolipid ratio of compound parenteral nutrition are far from the recommended values, while the heat-to-nitrogen ratio and glycolipid ratio of premixed parenteral nutrition are more ideal.

一项临床调查通过收集6家不同地区医院的1 207份肠外营养的处方，比较预混肠外营养与复合肠外营养在营养素供给量、总液体量、非蛋白质热卡、总氮量、热氮比等指标的差异。复合肠外营养与预混肠外营养均能基本满足患者营养需要。复合肠外营养在热氮比［（180~250）∶1］、糖脂比［（0.56~1.26）∶1］与推荐的热氮比［（100~150）∶1］、糖脂比（1.0∶1）差距较大，而预混肠外营养中的热氮比（167∶1）、糖脂比（0.8∶1）更为理想［72］。

2. Comparison of complications between compound parenteral nutrition and premixed parenteral nutrition: The blood infection rate of patients treated with premixed parenteral nutrition was lower than that of patients treated with compound parenteral nutrition.

两项关于肠外营养相关的血液感染的回顾性分析，纳入113 342例接受肠外营养治疗的患者。试验组为接受预混肠外营养的患者，共7 925例；对照组为接受复合肠外营养的患者，共105 417例。通过使用多元logistic回归对基线差异、危险因素和潜在混杂因素进行调整，并采用倾向评分匹配作为敏感性分析。预混肠外营养的血液感染率低于复合肠外营养的血液感染率（19.6%比25.9%，P<0.001；11.3%比16.1%，P<0.000 1）［72， 73］。

A retrospective analysis of gastrointestinal symptoms induced by compound parenteral nutrition and premixed parenteral nutrition, a total of 49 patients.The control group consisted of 29 patients receiving compound parenteral nutrition; the test group consisted of 20 patients receiving premixed parenteral nutrition.All patients in the test group developed nausea symptoms, while 6 patients in the control group developed nausea symptoms.The control group had better gastrointestinal tolerance.

Recommendation 28: Compound parenteral nutrition and premixed parenteral nutrition can meet the basic needs of patients who need supplemental parenteral nutrition.Premixed parenteral nutrition has a low blood infection rate and high safety, so it can be used as the first choice.For patients who need to supplement more electrolytes or have higher nutritional needs, compound parenteral nutrition can be selected for personalized parenteral nutrition.

([-]) Timing of termination of parenteral nutrition therapy
The purpose of parenteral nutrition therapy is to enable patients to maintain nutritional status, increase body weight, and heal wounds even if they cannot eat normally.For corresponding patients, if parenteral nutrition is stopped prematurely, the patient will be at risk of malnutrition and complications; however, the longer the parenteral nutrition is continued, the greater the risk of catheter-related infection and parenteral nutrition-related liver disease [74 ].Therefore, for neurosurgical critically ill patients receiving parenteral nutrition, every effort should be made to convert the patient to enteral therapy.In order to avoid overfeeding, while increasing enteral nutrition, parenteral nutrition should be appropriately reduced. Once the supply of enteral nutrition exceeds 60% of the target energy demand and can still be gradually increased, parenteral nutrition can be terminated.

Recommendation 29: For neurosurgical critically ill patients receiving parenteral nutrition who have no contraindications to enteral nutrition, efforts should be made to switch to enteral nutrition. With the increase of enteral nutrition, the amount of parenteral nutrition should be reduced accordingly. When enteral nutrition reaches 60% of the energy target, parenteral nutrition can be terminated.

[V. Use of additives in nutritional therapy for critically ill neurosurgery patients]

([-]) Micronutrients and antioxidants

The provision of micronutrients comprising a variety of trace elements and vitamins is an integral part of nutritional therapy.The difference between parenteral and enteral formulations is that parenteral formulations generally do not contain micronutrients for stability reasons, so parenteral formulations need to be added separately.Studies have shown that the lack of micronutrients is related to the poor prognosis of critically ill patients [75].However, whether outcomes can be improved after micronutrient supplementation is controversial and may be related to patient variability.

Oxidative stress is defined as an imbalance between increased nitroxide free radical response and endogenous antioxidant mechanisms.Commonly seen in patients with septic shock, severe pancreatitis, acute respiratory distress syndrome, severe burns and trauma.

Antioxidant micronutrients, mainly copper, selenium, zinc and vitamins E and C.In severe inflammatory conditions, their circulating levels drop below normal reference values.Note that these micronutrients are often used in higher doses as antioxidants and should not be confused with the daily supplemental doses required.Doses exceeding 10 times the DRI are not recommended in a clinical setting unless severe deficiency is demonstrated.

1. Selenium: The antioxidant mechanism of selenium is to activate the activity of glutathione peroxidase family antioxidant enzymes.Low selenium levels have been linked to severe inflammation, organ failure and poor prognosis.In a meta-analysis of 9 trials with a total of 792 patients with sepsis, the safety of high-dose selenium therapy (1 000–4 000 mg) was studied [76], and it was observed that it could help reduce the risk of selenium in sepsis. fatality rate.However, in the REDOXS trial, selenium supplementation did not show this effect [77]. The meta-analysis of Manzanares et al. [78] and the German cohort study [79] did not find any improvement in clinical efficacy.Also, since selenium is excreted by the kidneys, dosing above the DRI should be avoided in the setting of renal failure.

2. Vitamin C: The blood concentration of vitamin C in critically ill patients is low.Low plasma concentrations are associated with inflammation, severity of organ failure, and mortality.Preclinical studies have shown that high-dose vitamin C can prevent or restore microcirculatory blood flow damage by inhibiting the activation of nicotinamide adenine dinucleotide phosphate oxidase and inducible nitric oxide synthase, and can also prevent thrombin-induced Platelet aggregation and the expression of platelet surface selectin, thereby preventing the formation of microthrombosis [80].In addition, it restores vascular responsiveness to vasoconstrictors, protects the endothelial barrier by maintaining cyclic guanylate phosphatase, blocking phosphorylation, and preventing apoptosis.Finally, high doses of vitamin C can enhance antimicrobial defenses. Among 24 patients randomized to receive vitamin C (50-200 mg·kg-1·d-1) or placebo, no adverse safety events were observed in patients receiving vitamin C infusion.Compared with the placebo group, the SOFA score of patients in the vitamin C group decreased rapidly, and the inflammatory biomarkers (CRP and procalcitonin) were significantly reduced [81].Recently, Marik et al. [82] proposed that taking large doses of vitamin C, thiamine, and hydrocortisone can reduce mortality and prevent multiple organ failure in severe sepsis and septic shock.In fact, under the acidotic conditions of sepsis, vitamin C promotes the dissolution of microthrombi in capillaries, thus contributing to the improvement of microcirculation.

Recommendation 30: The provision of micronutrients is an important part of nutritional therapy.When parenteral nutrition is administered to critically ill neurosurgical patients, micronutrients (ie, trace elements and vitamins) should be added individually every day.

Recommendation 31: Antioxidant micronutrients require higher doses when used as antioxidants, and should not be used routinely until severe deficiencies are confirmed.

([-]) Vitamin D
As long as there is sunlight exposure and good liver and kidney function, the human body can synthesize sufficient vitamin D3.Critically ill patients are exposed to sunlight for a long time and are often accompanied by abnormal liver and kidney function, so vitamin D deficiency will occur repeatedly, which is associated with poor prognosis, including increased mortality, prolonged hospital stay, higher incidence of sepsis and need for medical treatment. Long duration of mechanical ventilation, etc. [83].

It has been proven that critically ill patients cannot correct low vitamin D plasma concentrations solely by nutrient dosage, and need to undergo loading therapy [84]. According to body weight and initial level, it is safe to give a high dose once in the first week.

The meta-analysis on vitamin D included 7 randomized trials, with a total of 716 cases of severe adult patients. The test dose was between 3 and 20 units of vitamin D54. Compared with placebo, the mortality rate of patients supplemented with vitamin D3 was reduced No adverse reactions were observed during the 6-month follow-up [85].

推荐建议32：证实维生素D缺乏（25-羟基维生素D<12.5 ng/ml或50 nmol/L）的神经外科重症患者需要补充维生素D3治疗，治疗时建议给予负荷量（单次50 000~600 000单位维生素D3）后再进行营养剂量（DRI 600单位）治疗。

([-]) Glutamine

GLN is a normal component of protein, accounting for about 8% of all amino acids. It mainly transports nitrogen between cells and (or) organs, and serves as a raw material for rapid cell proliferation.Under physiological conditions, the human body can maintain adequate GLN levels through daily nutrient intake and endogenous synthesis (skeletal muscle and liver).GLN is generally included in standard enteral nutrition formulations but not in standard parenteral nutrition solutions for stability reasons.

At present, there is no direct research support for the relationship between GLN levels and prognosis in critically ill neurosurgical patients. In other studies of critically ill patients, Rodas et al. [86] showed that there is a U-shaped association between plasma GLN levels and prognosis.Low plasma GLN levels in critically ill patients are associated with poor prognosis.Several randomized trials have confirmed that in burn and trauma patients, if the plasma GLN level is low, additional GLN supplementation can reduce the occurrence of infection complications and promote wound healing [87, 88].

However, not all critically ill patients lack GLN.

Recommendation 33: It is not necessary to supplement GLN when the enteral nutrition therapy protein reaches the standard for neurosurgery critically ill patients; for patients with severe traumatic brain injury, GLN supplementation can be considered when the plasma GLN level decreases; for patients receiving standard total parenteral nutrition, Note the supplementary GLN.For patients with liver and kidney failure, additional supplementation with GLN is not recommended.

(End of this chapter)