Objective To study the changes of nitrogen balance and nutritional support treatment in patients with early coma of heavy traumatic brain injury, to reduce the mortality and disability rate and improve the survival quality of patients. Methods We observed the nitrogen excretion in 78 cases after heavy traumatic brain injury for 10 days, and analyzed the relationship between nitrogen excretion and condition and body weight, and also provided gastrointestinal or extra-gastrointestinal nutritional supplementation. Results The average daily nitrogen excretion of the patients after traumatic brain injury was 18g (8-44g), and the total negative nitrogen balance of the patients was 58g (28-108g) in 10 days, with an average weight loss of 4.7kg (2.5-6.0kg). Conclusion Choosing an appropriate and rational nutritional supplementation route and appropriate amount of protein, micronutrients, and calories are important methods to reduce complications and improve survival rate.
With the advancement of surgical level and the improvement of circulatory, respiratory and other system control techniques, the treatment of early metabolic disorders and nutritional support for patients after heavy traumatic brain injury has become increasingly important. Due to the stress caused by trauma, the body of patients in the early stage of traumatic brain injury is in a state of high metabolism, high catabolism and abnormal metabolism of nutrients and hormones, and the application of hormones, dehydrating agents and restriction of water input and insufficient nutritional supplementation in the clinical treatment of cerebral edema after traumatic brain injury can put the body in a serious negative nitrogen balance. The specific manifestations are hypoproteinemia, albumin/globulin inversion, immune deficiency, prolonged wound healing time, infection, and in severe cases, multi-organ organ failure, which increases the disability and mortality rate of patients. We analyzed and summarized 78 cases of heavy traumatic brain injury patients admitted to our department in the past three years, and chose the appropriate time and route to provide nutritional support treatment, with good clinical results.
Data and Methods
I. General data: From January 1999 to December 2001, 78 patients with heavy traumatic brain injury were admitted to our department, including 42 males and 36 females; age 4-72 years old, average age 39 years old. The injury glasgow score was 3-8, with a mean score of 6. All patients underwent CT scan of the head before surgery, which showed intracranial hematoma volume of 40-120 ml. 38 patients had epidural hematoma, 26 patients had subdural hematoma, and 8 patients had epidural with subdural or intracerebral hematoma. 48 patients had brain herniation before surgery, and all patients underwent emergency hematoma removal or hematoma removal with debridement and decompression under general anesthesia within 1.5-8 hours after trauma. Some patients underwent tracheotomy to control breathing and sputum aspiration, while effectively controlling the circulatory and urinary systems.
Monitoring and determination of nitrogen metabolic indexes and nutritional status: 24-hour urine was taken from patients for 10 consecutive days from the first day after surgery, and the amount of nitrogen eliminated was determined by Kjeldahl method. The calculation formula is: nitrogen balance = nitrogen intake (oral protein amount g/6.25 or intravenous nitrogen input) – nitrogen excretion (urinary urea amount × 1.2 + 2.0g). Nutritional status was determined by measuring the patient’s weight before surgery and on the first day, seventh day and 10th day after surgery, respectively, and comparing the actual measured results after calculating the ideal weight according to Braca’s modified formula. Ideal weight = [height (cm) – 100] × 0.9. If the measured weight was ±10% of the ideal weight, it was considered normal, and a decrease of 10%-20%, 20%-40% and 40% or more was considered mild, moderate and severe malnutrition, respectively. The patient’s plasma protein level is also monitored, and the criteria are 35-50g/L-normal, 28-35g/L-mild, 21-27G/l-moderate, and less than 21g/L-severe malnutrition, and the patient’s immune function is also determined.
All patients were given nasal diet with 24-hour continuous drip on the third day after surgery, and the drip rate was controlled by infusion pump according to the patient’s response and tolerance, and 1/3-1/2 of the calculated amount was given for the first 1-2 days, and the full amount was supplied later. Patients with more severe disease were given a small amount of elemental diet along with intravenous nutrition. The amount of nutrition was calculated according to the Hanrris-Benedict formula, with 125-167 kJ/kg.d [30-40 kcal/kg.d] of calories and 0.25-0.30 g/kg.d of nitrogen, equivalent to 1.5-2.5 g/kg of protein. Adjustments were also made based on daily measurements of patients’ biochemical parameters, body weight, and response to and tolerance of nutritional support.
Results
The results of the analysis showed that the urinary nitrogen elimination fluctuated from 8 to 44 g/d, with a total nitrogen elimination of 28-108 g over 10 days, averaging 58 g. After 10 days, the patient lost 2.5-6.0 kg, averaging 4.7 kg, compared to the preoperative weight. plasma protein level measurements and immune function measurements were reduced to varying degrees in the early stages of trauma. The nutritional status of the patients improved to varying degrees after gastrointestinal, total gastrointestinal and parenteral + gastrointestinal nutrition, as evidenced by weight gain, stable vital signs, faster wound healing, improved glasgow score, and better condition. Among the 78 patients in this group, except for 12 patients who died within 2-8 days after surgery due to excessive disease, the remaining 66 patients had 5 cases of vegetative survival, 14 cases of severe disability, 27 cases of moderate disability, and the rest were good.
Discussion
I. Relationship between post-traumatic stress response and nitrogen balance
Hypermetabolism, hypercatabolism and abnormal metabolism of nutrients and hormones can occur after severe traumatic brain injury, and these changes can disrupt the internal environment and affect cellular energy metabolism and function, leading to deterioration of the patient’s condition due to impairment of organ function and increasing the disability and mortality rate of patients [1-6]. As early as the 1940s, Drew and Cooper found that proteolytic metabolism was significantly increased in patients after traumatic brain injury, with an average daily urinary elimination of 10-25 g of nitrogen during the first two weeks, up to 34 g, and a peak of nitrogen excretion on days 5-8, which could be as high as 338 ± 106 mg/kg in 24 h. Clifton 1984 reported 14 cases of heavy energy expenditure and altered nitrogen balance after traumatic brain injury and found that their static expenditure rate was 138±37% of that of uninjured patients of the same age, sex and body surface area, with a mean nitrogen excretion of 20±6.4 g/d, similar to that of patients with 20%-40% of the burn area.Haider reported a basal metabolic rate of 127-278% in a group of patients after severe traumatic brain injury, with a mean of 170%[2-7] . Therefore, they all concluded that the increased basal metabolic rate after traumatic brain injury caused an increase in nitrogen elimination.
II. Relationship between the severity of trauma and nitrogen excretion
In the clinical treatment and observation of this group, we found that patients with severe traumatic brain injury and low Glasgow score had high catabolic rate, and their urinary nitrogen excretion was more and longer, and their prognosis was also poor; while the nitrogen excretion of less severe patients began to decline several days after the injury. In our group of 78 patients, the 24-hour urinary nitrogen excretion ranged from 8 to 44 g (mean 18 g). 12 patients with severe traumatic brain injury who died had a 24-hour nitrogen excretion of up to 44 g, but the urinary nitrogen excretion gradually decreased after the clinical signs of brain death. The amount of nitrogen excretion also varies in different times after traumatic brain injury, with the highest amount of nitrogen excretion in the first 1-3 days after surgery, and the amount of nitrogen excretion in 24 hours often exceeds 20 g. This may be due to the traumatic brain injury itself and the large amount of tissue protein decomposition caused by the trauma caused by surgery, while the increase of nitrogen excretion in the late traumatic brain injury is often due to inflammation, hyperthermia, decubitus ulcers and other complications.
Third, the nutritional status of trauma patients monitoring methods
There are many methods to monitor the nutritional status of patients in clinical practice. Regular weight measurement can observe the nutritional status of patients, but this method is not accurate enough to measure the nutritional status of patients due to water and sodium retention caused by the early application of corticosteroids after traumatic brain injury. Regular measurement of plasma protein can observe the dynamic changes of protein and protein consumption in patients after injury, but such changes usually appear late and are not significant for the evaluation of the nutritional status of patients with traumatic brain injury in the early stage. Prethyroxine binding protein, transferrin, total lymphocyte count and creatinine/height index are often used to assess the nutritional status of patients. Periodic measurements of biceps and triceps gross can only roughly determine myostatin catabolism in patients with traumatic brain injury [3, 6. 10. 11]. We believe that measurement of 24-hour urinary nitrogen elimination in patients by Kjeldahl method is currently the best method to evaluate the nutritional status of patients, and this method was used to measure changes in nitrogen balance in all 78 patients in our group. If it is necessary to measure the feces, because the amount of nitrogen excreted through the feces and other channels is relatively constant, so the total amount of nitrogen excreted in 24 hours is generally added 2-4g to the measured amount of nitrogen in the urine.
Fourth, the impact of malnutrition on the prognosis of patients
Short-term negative nitrogen balance has less impact on the body, while heavy traumatic brain injury patients have a heavier impact on the body due to the long coma and severe and long-term negative nitrogen balance. The application of hormones and barbiturates can also destroy the immune function of the organism, mainly manifesting as decreased anti-infection ability, prone to intracranial infections and pulmonary infections, etc. It can also cause slow healing of trauma, hypoproteinemia, decreased plasma colloid osmotic pressure, decreased effective circulating blood volume, leading to insufficient cerebral blood supply, aggravating cerebral edema, and in severe cases, multi-organ organ failure, leading to patient death [6, 7, 11 ].
V. Relationship between early nutritional support and prognosis
Rapp et al. found that early extragastric or gastrointestinal nutrition increased the resistance of patients and reduced complications [10].Hadley et al. reported a group of traumatic brain injury cases in 1986 and divided them into vena cava nutrition and gastrointestinal nutrition groups for analysis and found that the former had a mean nitrogen excretion of 22.4 ± 5.9 g/d and a mean nitrogen uptake of 13.1 ± 4.6 g/d. The average weight loss within 2 weeks after surgery was 4 kg, while the latter was 18.5±7.0 g/d, 11.4±6.4 g/d and 5.7 kg, respectively [1]. Recent studies have found that many specific nutrients have significant immunomodulatory effects, and nutritional support enriched with these nutrients, especially enteral nutrition, can enhance the barrier function of the intestinal mucosa, reduce endotoxin and bacterial translocation, prevent enterogenic infections and multi-organ organ failure, and improve the quality of survival of patients.
VI. Nutrient supplementation route and nutrient selection
Gastrointestinal nutrition: It refers to the supplementation of nutrition through the mouth, nasogastric tube or enterostomy. It is suitable for patients who are comatose after traumatic brain injury and have normal gastrointestinal tract function, and the advantages of gastrointestinal nutrition have been affirmed in recent years, and it is believed that the earlier the better [11, 12]. The elemental diet is a diet composed by formula, containing various essential nutrients, consisting of easily absorbed monomeric substances, inorganic ions and emulsified fat particles. Commonly used elemental diets include Vital, Vivones HN, Compound Nutrients, High Nitrogen Combination, Vital Health High Nitrogen and the cellulose-based Nutrison fiber. Since the elemental diet is composed of monomeric substances, it can be absorbed directly or can be completely absorbed after a little digestion, leaving no or very little residue. If the elemental diet does not taste good, it can be continuously dripped through nasogastric tube or gastrostomy tube. At first, a small amount (1000ml) and low concentration (8%) should be continuously dripped for 8-12 hours, and then gradually increase the amount, concentration and drip time. When the concentration reaches 25%, 1ml can supply 4.18kj (1kcal) of calories, and the total amount of 24 hours can be 2500-3000ml or more. The application of elemental diet is easier to control and manage than parenteral nutrition, but complications such as hyperosmolar diarrhea, nausea and vomiting, misabsorption or metabolic disorders can also occur.
Parenteral nutrition: Total or partial nutrition through deep veins, superficial veins, arteriovenous catheters for dialysis in renal failure patients, intramuscular and subcutaneous routes. It is suitable for people with gastrointestinal dysfunctional absorption, short-term nutrition can be supplied by superficial vein, while long-term nutrition should be supplied by deep vein or central vein placement. The nutrient solution should contain carbohydrates, fats, proteins, electrolytes, trace elements, vitamins and water. The concentration can be adjusted for different patients, for example, in the early stage of traumatic brain injury, the total amount of fluid should also be reduced appropriately. Electrolytes, vitamins and trace elements should be added to these nutrition solutions in appropriate amounts. If long-term parenteral nutrition is needed and the peripheral superficial veins are severely damaged, deep venous cannulation should be chosen. The changes of vital signs, fluid intake and output, blood glucose, electrolytes and liver and kidney function should be observed regularly for timely correction and treatment.
Extragastric nutrition + gastrointestinal nutrition: In the early stage after traumatic brain injury, when the gastrointestinal function is not fully recovered and needs to be administered from the vein, appropriate nutrition can be given via extragastric, while a certain amount of nutrition can be given via gastrointestinal tract to assist. In the late stage of traumatic brain injury, when the intravenous medication is reduced and the gastrointestinal function has been gradually normalized, it should be gradually changed to gastrointestinal nutrition, which can reduce the adverse reactions or complications of single method of supplemental nutrition. This method was used in 78 patients in this group, and the effect was good.
Seven, the timing of nutrient supply and supply amount
In the early stage of traumatic brain injury, patients are in a high metabolic and high catabolic state, if the energy intake is insufficient, it increases the extra catabolic consumption of the body, which rapidly causes malnutrition and eventually affects the prognosis and recovery of patients, meanwhile, inappropriate or excessive nutritional support is difficult to be tolerated by patients on the one hand, and also adds excessive burden to the respiratory and circulatory systems and liver [10]. norton advocates that in the post-traumatic brain injury Norton advocates total parenteral nutrition on the third day after traumatic brain injury until the patient can tolerate gastrointestinal nutrition [9]. Recent studies have shown that the earlier enteral nutrition is given after trauma, the better, and it is generally considered that nutritional support should be given as early as possible after 24 hours of traumatic brain injury if the patient is hemodynamically stable; the disturbances of water, electrolytes, blood osmolality and acid-base balance are largely corrected; hyperglycemia, hyperlipidemia and hyperazotemia are largely controlled; and there is no serious bleeding tendency [11]. Patients with traumatic brain injury are different from patients with intestinal fistula and abdominal surgery, as the former have normal digestive and absorption functions, and nutrition can be supplemented in small amounts through the gastrointestinal route at the early stage after traumatic brain injury, and high-energy nutrition is gradually supplemented through the gastrointestinal route when intestinal sounds are restored to reduce the complications of intravenous supplementation. The best solution is to supply as much as possible, which can be calculated according to the Hanrris-Benedict formula, with 125-167 kJ/kg.d [30-40kcal/kg.d] of calories and 0.25-0.30g/kg.d of nitrogen. According to the patient’s daily nitrogen excretion and protein supplementation, together with the daily basal consumption supplementation, patients with heavy traumatic brain injury The nutritional requirement of a patient with severe traumatic brain injury can be three times that of a normal person, and if the patient develops hyperthermia or is on a ventilator, his nutritional supplementation should also be increased appropriately to supplement the additional consumption.