Nineteenth Century Medical Guide

【Wait for change】

[357 was sentenced to lift the ban because of some indescribable content, but it happens to be a weekend and I can only let the editor do it tomorrow]

[To prevent full attendance from being stopped after more than seven days, first lose a chapter, and then try to complete the revision within a week.When my mother and father-in-law are discharged from the hospital, I will resume normal updates. Middle-aged people have a lot of things, forgive me】

(22) Eicosapentaenoic acid and [-]-carbahexaenoic acid

国际脂肪酸和脂质研究协会建议健康人每天摄入500 mg EPA及DHA［89］。此剂量的3~7倍定义为高剂量。α-亚麻酸是一种必需的ω-3不饱和脂肪酸，具有潜在的脑保护、脑动脉血管扩张和神经可塑性方面的多效性作用。

At present, there are no relevant clinical trials on the effect of adding EPA and DHA on the prognosis of neurosurgery critically ill patients with enteral nutrition. Among patients with ARDS and acute lung injury, 8 studies were included in the meta-analysis, and the results did not show any benefit, only suggesting that PO2 /FiO2 tends to increase (RR=22.59, 95%CI: -0.88~46.05, P=0.06), but PO2/FiO2 is affected by ventilator settings, liquid state, body position, etc., and its value changes rapidly, which is not good outcome indicators.In a post hoc study of a large RCT Meta Plus of Immunomodulatory Nutrients [98], it was found that GLN-rich, fish oil-rich, and antioxidant-enriched high-protein compared with isocaloric high-protein, early (EPA+DHA)/long-chain The increase in the ratio of fatty acid plasma levels is harmful to critically ill patients.Therefore, high doses of omega-3 UFA-rich nutrients should not be routinely added.

Intravenous fat emulsions based solely on soybean oil enriched in 18 carbon omega-6 FAs ​​should be avoided when performing parenteral nutrition therapy.A number of new fat emulsions are available, incorporating olive oil, fish oil and coconut oil in various combinations.Meta-studies have shown the advantages of fat emulsions enriched with fish oil or olive oil [99].A prospective randomized study showed that the fish oil group had a lower incidence compared with other lipid emulsions [100]. Grau-Carmona et al[101] found in a multi-center prospective randomized double-blind study that compared with the use of long chain fatty acids (long chain fatty acids (LCT)/MCT) emulsion alone, the use of LCT (such as soybean oil) Lipid emulsions of , MCT and fish oil can significantly reduce the infection rate. Adding MCT and special nutrients that help LCT digestion and absorption, such as taurine and L-carnitine, are easier to digest and absorb. Many prospective studies have compared these new lipids. Compared with other lipid emulsions, and compared with soybean oil-based lipid emulsion, the results showed that patients using the new lipid emulsion shortened the hospital stay and also helped to reduce the infection rate [102, 103].The use of fish oil-rich fat emulsion in patients with sepsis can help shorten the length of ICU stay and mechanical ventilation [104].

Recommendation 34: It is not recommended to routinely add EPA/DHA or use high-dose enteral formulas rich in omega-3 fatty acids for enteral nutrition in critically ill neurosurgical patients.

Recommendation 35: EPA+DHA-rich fat emulsions can be used for parenteral nutrition in neurosurgery critically ill patients.

[[-]. Nutritional therapy for neurosurgery critically ill patients under special circumstances]

([-]) Shock state

When to start enteral nutrition in neurosurgical critically ill patients in shock state is controversial.In very hemodynamically unstable patients, enteral nutrition is unlikely to help improve instability and may even further impair already impaired splanchnic perfusion, a retrospective review of 259 hemodynamically unstable patients A clinical observational study found that among those receiving enteral nutrition early, 3 cases developed intestinal ischemia and intestinal perforation [105].Therefore, in the case of uncontrolled shock, it is recommended to suspend the initiation of enteral nutrition.Persistent lactic acidosis may help identify a state of uncontrolled shock.

After the hemodynamics is initially stabilized, small doses of enteral nutrition can be considered without waiting for all vasopressor drugs to be discontinued.In a large observational study, early initiation of enteral nutrition (>48 h) in hemodynamically "relatively stable" patients who remained on at least one vasopressor after fluid resuscitation compared with late enteral nutrition (>48 h) Enteral nutrition (≤50 h) can reduce the mortality of patients.Another recent retrospective study showed that enteral nutrition did not affect hemodynamic stability, as indicated by whether the dose of norepinephrine was increased by more than 106%.These results suggest that after initial control of shock, small doses of enteral nutrition can be initiated if the dose of vasopressors is stabilized or reduced [[-]].

Recommendation 36: If the shock is not controlled and the hemodynamic and tissue perfusion goals are not achieved, it is recommended to postpone enteral nutrition, but after the initial hemodynamic stabilization (stabilization or reduction of vasoactive drugs), low-dose nutrition should be started immediately. dosing enteral nutrition.

([-]) Stress ulcer and upper gastrointestinal bleeding
Acute gastrointestinal mucosal erosion, ulcer, bleeding and other lesions that occur in the body under severe stress can lead to gastrointestinal bleeding or even perforation in severe cases.The latest multicenter retrospective survey showed that the incidence of gastrointestinal bleeding in Chinese neurosurgery critically ill patients was 12.6%.An RCT comparing ranitidine and sucralfate reported that enteral nutrition was an independent protective factor against gastrointestinal bleeding [107].A meta-analysis recommended the use of enteral nutrition to prevent stress ulcers and gastrointestinal bleeding [108].

The main reason for prohibiting feeding/enteral nutrition in patients with upper gastrointestinal bleeding is the fear of rebleeding, so for high-risk patients with rebleeding, enteral nutrition will be delayed after bleeding. The ESICM guidelines recommend starting enteral nutrition within 24–48 hours after bleeding stops [109].If the bloody gastric content is <100 ml/d, the enteral nutrition pump can be used to pump the nutrient solution, the recommended feeding speed (20-50 ml/h) is fed, and the gastric juice occult blood test is detected once a day until the second time is normal; If the gastric content is >1 ml/d, nasogastric tube feeding should be used with caution, and gastrointestinal decompression combined with nasojejunal tube feeding can be considered [2]. If it is still not tolerated, supplementary parenteral nutrition therapy should be considered.

Recommendation 37: Enteral nutrition is a protective factor for preventing stress ulcer and upper gastrointestinal bleeding, and early use of enteral nutrition is recommended for patients with stress ulcer.For patients with upper gastrointestinal bleeding, it is recommended that enteral nutrition be administered 24–48 hours after the bleeding stops.

([-]) Mild hypothermia treatment
Under sub-low temperature conditions, the human body's metabolic rate is low, gastrointestinal motility is weak, whether enteral nutrition can be tolerated, and whether complications such as vomiting and aspiration are concurrent are issues that need to be resolved.British researchers Williams and Nolan [111] studied patients undergoing hypothermia therapy after cardiac arrest and found that during the hypothermia period, the enteral nutrition tolerance rate was 72% of the prescribed dose; 95% of the dose; normothermic period, enteral nutrition tolerance rate was 100%.Nausea, vomiting and other complications occurred 24 to 48 hours after the start of hypothermia treatment.Therefore, giving 75% of the corresponding normal temperature dose during mild hypothermia treatment, or adopting a post-pyloric feeding method can increase the patient's tolerance and reduce the risk of nausea, vomiting, and aspiration.

Recommendation 38: Low-dose (75%) enteral nutrition can be given during mild hypothermia treatment, and the dose can be gradually increased after rewarming.Protocols to improve gastrointestinal tolerance should be used more aggressively during mild hypothermia therapy.

([-]) Prone position ventilation
The energy demand of patients with prone position ventilation is 30%-50% higher than that of patients with ordinary mechanical ventilation, and due to the position, the intra-abdominal pressure of patients increases and the ability of gastric peristalsis decreases, resulting in 82% of patients with enteral nutrition in prone position. Tolerance problems, the daily feeding volume is lower than that of patients in the supine position, which makes the risk of malnutrition in patients in the prone position as high as 70% [112].Studies have shown that enteral nutrition is feasible, safe, and not associated with an increased risk of gastrointestinal complications in critically ill patients with severe hypoxemia receiving mechanical ventilation in the prone position [113].Therefore, discontinuation of enteral nutrition therapy simply because of prone position ventilation is not recommended.

Measures to improve feeding tolerance while in prone position:

1. Before the implementation of prone position ventilation, it is recommended to stop enteral nutrition 1 hour in advance, and withdraw to check GRV to prevent reflux and aspiration during turning over and prone position ventilation.

2. The air bag pressure of the artificial airway should be measured before and after the start of prone position ventilation, and the air bag pressure should be maintained at 2.94 kPa.

3. Pay attention to avoid oppressing the patient's abdomen when placing the ventilation position in the prone position, and keep the head of the bed elevated to reduce intra-abdominal pressure and avoid increasing gastric emptying obstacles.

4. The use of prokinetic drugs can help reduce the occurrence of enteral nutrition intolerance and increase the amount of enteral nutrition.

5. Conditional medical institutions can monitor gastric antrum motion index by ultrasound to guide the implementation of enteral nutrition in prone position ventilation patients.

Recommendation 39: It is not recommended to stop enteral nutrition therapy simply because of prone position ventilation, and attention should be paid to measures to improve feeding tolerance.

([-]) Mechanical ventilation
Mechanical ventilation is one of the causes of iatrogenic underfeeding.Spontaneous breathing disorder in critically ill neurosurgery patients will prolong the duration of mechanical ventilation, lead to a high risk of malnutrition, and lead to adverse clinical outcomes.Neurosurgery critically ill patients with impaired hypothalamus, brainstem and other nerve functions are prone to gastric emptying disorders. The lower the Glasgow Coma Scale (GCS) score, the greater the impact of mechanical ventilation support on the patient's energy demand and gastrointestinal function.

In the early stage of mechanically ventilated critically ill neurosurgical patients, hemodynamic instability is common at the same time. The use of enteral nutrition at this stage should refer to the recommendations for enteral nutrition in shock state.After resuscitation, as long as the anatomy of the gastrointestinal tract is complete and has certain functions (especially motor function/absorption function), enteral nutrition should be started as soon as possible, and recovery of bowel sounds is not a necessary condition for enteral nutrition.Studies have shown that patients who start enteral nutrition early (within 24-48 h) can reduce the time of mechanical ventilation, and early low-calorie feeding (<20 kcal·kg-1·d-1, protein 1.2-2.0 g·kg-1· d-1) It also applies to mechanically ventilated patients [114].Patients receiving enteral nutrition at the same time should monitor their daily energy requirements every 7 days to facilitate the adjustment of nutritional support strategies.

Studies have shown that enteral nutrition therapy with indwelling nasogastric tubes in neurosurgery patients with severe mechanical ventilation can help patients regain consciousness, improve nutritional indicators, reduce the incidence of complications such as VAP, reflux, and aspiration, and shorten the course of the disease.For enteral nutrition patients, elevating the head of the bed by 45° helps to empty the gastric contents and reduce the occurrence of complications such as delayed gastric emptying, increased gastric residual volume, gastroesophageal reflux, vomiting, aspiration, and VAP [115].Foreign studies have also confirmed that raising the head of the bed >30° can help reduce oral secretions, reflux, and aspiration in mechanically ventilated patients without increasing the risk of pressure sores [116].

Recommendation 40: It is not recommended to delay the initiation of enteral nutrition in neurosurgery critically ill patients who are under pure mechanical ventilation.

([-]) Sedation and analgesia

Patients with sedation and analgesia have reduced energy requirements, and sedation and analgesia can delay gastric emptying. Regardless of whether neuromuscular blockers are used at the same time, the risk of feeding intolerance may increase in deeply sedated patients.The use of opioid sedative and analgesic drugs can affect the nutritional metabolism of patients, reduce gastrointestinal motility, cause gastric retention, constipation, gastroesophageal reflux, weight loss, malnutrition and other nutritional problems, which will hinder the results of neurosurgical treatment.

Recommendation 41: Under sedation and analgesia, lower calorie feeding can be used for critically ill neurosurgery patients.

【VII. Management of nutritional therapy process for critically ill patients in neurosurgery】

A number of clinical studies have found that in the intervention group using feeding process management, the number of days of enteral nutrition implementation was significantly increased compared with the control group, the start time of enteral nutrition was also earlier, and the mortality rate was reduced, the length of hospital stay was shortened, and the prognosis of patients was effectively improved.It is recommended to adopt feeding process management during nutritional therapy (Figure 1), and to monitor and deal with feeding intolerance (Figure 2).

Recommendation 42: It is recommended to apply process management in the nutritional treatment of critically ill patients in neurosurgery.

【VIII. Nursing during nutritional therapy for critically ill patients in neurosurgery】

Nursing is an important part of nutritional therapy practice. A multidisciplinary nutritional therapy team consisting of doctors, nutrition experts, nurses and pharmacists is established during the nutritional therapy of critically ill patients in neurosurgery, which helps to monitor the nutritional status of nutritional therapy patients. Reduce gastrointestinal intolerance, and reduce hospital stay and medical costs.

1. Operation requirements: Nursing During enteral nutrition operations, strict aseptic operation procedures need to be paid attention to, avoiding repeated use of disposable items such as syringes and nutrition pump tubes, and maintaining good hand hygiene habits can help reduce bacterial contamination of enteral nutrition solutions risk, thereby reducing the occurrence of bacterial diarrhea.At the same time, nursing needs to pay attention to the "three degrees" of gastrointestinal nutrition, namely the temperature, speed and concentration of the nutrient solution. It is recommended to use a dedicated gastrointestinal nutrition pump to provide a stable infusion rate and a moderate temperature of the nutrient solution to reduce gastrointestinal reactions.

2. Monitoring and adjustment of nutrition therapy: During nutrition therapy, it is often necessary to adjust the feeding strategy according to the patient's gastrointestinal tract condition. It is recommended that the nurses measure the abdominal circumference routinely every day, monitor and record the frequency, character and quantity of stool, and Aspirate the gastric contents before starting enteral nutrition every day, understand the gastric residual situation and give feedback to the doctor, and formulate enteral nutrition strategies together with the doctor.When gastrointestinal intolerance occurs, the frequency of monitoring needs to be increased, and gastrointestinal nutrition should be adjusted in time according to changes in the patient's condition.

3. Body position: In the absence of contraindications, the head of the bed should be raised by 30°~45° during enteral nutrition, and attention should be paid to avoid pressure sores, which can reduce aspiration pneumonia caused by aspiration.

4. Tube: Continuously infuse nutrient solution every 4 hours or flush the tube with 20-40 ml of warm water before and after each interrupted infusion or administration.The nutrient infusion line should be changed once a day.Enteral nutrition with a percutaneous ostomy tube requires daily cleaning of the stoma with warm soapy water or clean water, while preventing the tube from clogging and falling off.

Recommendation 43: Nursing is recommended as an integral part of the nutritional therapy team for critically ill neurosurgical patients.