Comparison of urinary urea nitrogen excretion and measured energy expenditure in spinal cord injury and nonsteroid-treated severe head trauma patients

Validation of basal metabolic rate equations in persons with innervated and denervated chronic spinal cord injury

Basal metabolic rate (BMR) measurement is time consuming and requires specialized equipment. Prediction equations allow clinicians and researchers to estimate BMR; however, their accuracy may vary across individuals with chronic spinal cord injury (SCI). The objective of this study was to investigate the validity of SCI-specific equations as well as able-bodied (AB) prediction equations in individuals with upper motor neuron (UMN), lower motor neuron (LMN), and females with SCI. Twenty-six men and women with chronic SCI (n = 12 innervated males, n = 6 innervated females, n = 8 denervated males) participated in this cross-sectional study. BMR values were measured by indirect calorimetry. Body composition (dual-energy X-ray absorptiometry and anthropometrics) assessment was conducted. AB-prediction equations [Cunningham, Nelson, Owen, Harris and Benedict, Mifflin, Schofield, Henry] and SCI-specific equations [Chun and Nightingale & Gorgey] were used to estimate and validate BMR. The accuracy of AB-specific FFM equations in predicting BMR was evaluated using Bland-Altman plots, paired t-tests, and error metrics. Measured BMR for innervated males, females, and denervated males was 1436 ± 213 kcal/day, 1290 ± 114, and 1597 ± 333 kcal/day, respectively. SCI-specific equations by Chun et al., Nightingale & Gorgey, and AB-specific FFM equations accurately predicted BMR for innervated males. For the denervated males, Model 4 equation by Nightingale & Gorgey was not different (p = 0.18), and Bland-Altman analyses showed negative mean bias but similar limits of agreement between measured and predicted BMR for the SCI-specific equations and AB-specific FFM equations. We demonstrated that SCI-specific equations accurately predicted BMR for innervated males but underpredicted it for denervated males. The Model 4 equation by Nightingale & Gorgey accurately estimated BMR in females with SCI. Findings from the current study will help to determine caloric needs in different sub-groups of SCI.

Association between energy surplus and intensive care unit length of stay in critically ill patients: A retrospective cohort study

BACKGROUND

Patients experiencing persistent critical illness have poor short-term and long-term outcomes and consume disproportionate amounts of health care resources. Nutrition optimization may improve outcomes, though few data exist on resting energy expenditure and nutrition requirements. We hypothesized that increased energy surplus per day is associated with increased intensive care unit (ICU) length of stay (LoS) in critically ill patients.

METHODS

Patients from a single ICU at Royal London Hospital were included in this retrospective cohort study.

EXPOSURE

energy surplus measured by serial indirect calorimetry (IC) and nutrition intake.

INCLUSION CRITERIA

mechanical ventilation of ≥3 days and expected to remain ventilated.

PRIMARY OUTCOME

ICU LoS.

RESULTS

Across 30 patients (median LoS 21 days), increased ICU LoS was associated with actual daily energy intake surplus to resting energy expenditure (REE) (R2 0.16; P < 0.005). Median REE was less than predicted energy requirements: 24 kcal per day per kilogram of ideal body weight (IBW) (interquartile range [IQR], 20-28) vs 28 kcal/day/kg IBW (IQR, 26-29) (P < 0.001). Patients with COVID-19 had a median energy surplus (actual intake- REE) + 344 kcal/day (IQR 35-517) vs -57 kcal/day (IQR -324 to 211) in other patients (P = 0.011); however, they had a median LoS of 44 days (IQR 26-58) vs 10 days (IQR 7-24), respectively (P < 0.001). Patients with obesity had a median energy deficit of -32 kcal/day (IQR -384 to 335) vs +234 kcal/day (IQR -79 to 499) for nonobese patients (P = 0.021).

CONCLUSION

Overfeeding represents an easily modifiable factor to improve outcomes in patients experiencing persistent critical illness, for which IC may be useful.

Nutrition Education to Reduce Metabolic Dysfunction for Spinal Cord Injury: A Module-Based Nutrition Education Guide for Healthcare Providers and Consumers

Spinal cord injury (SCI) results in a high prevalence of neurogenic obesity and metabolic dysfunction. The increased risk for neurogenic obesity and metabolic dysfunction is mainly due to the loss of energy balance because of significantly reduced energy expenditure following SCI. Consequently, excessive energy intake (positive energy balance) leads to adipose tissue accumulation at a rapid rate, resulting in neurogenic obesity, systemic inflammation, and metabolic dysfunction. The purpose of this article is to review the existing literature on nutrition, dietary intake, and nutrition education in persons with SCI as it relates to metabolic dysfunction. The review will highlight the poor dietary intakes of persons with SCI according to authoritative guidelines and the need for nutrition education for health care professionals and consumers. Nutrition education topics are presented in a module-based format with supporting literature. The authors emphasize the role of a diet consisting of low-energy, nutrient-dense, anti-inflammatory foods consistent with the Dietary Guidelines for Americans' MyPlate to effectively achieve energy balance and reduce the risk for neurogenic obesity and metabolic dysfunction in individuals with SCI.

Energy expenditure and nutrient intake after spinal cord injury: a comprehensive review and practical recommendations

Many persons with spinal cord injury (SCI) have one or more preventable chronic diseases related to excessive energetic intake and poor eating patterns. Appropriate nutrient consumption relative to need becomes a concern despite authoritative dietary recommendations from around the world. These recommendations were developed for the non-disabled population and do not account for the injury-induced changes in body composition, hypometabolic rate, hormonal dysregulation and nutrition status after SCI. Because evidence-based dietary reference intake values for SCI do not exist, ensuring appropriate consumption of macronutrient and micronutrients for their energy requirements becomes a challenge. In this compressive review, we briefly evaluate aspects of energy balance and appetite control relative to SCI. We report on the evidence regarding energy expenditure, nutrient intake and their relationship after SCI. We compare these data with several established nutritional guidelines from American Heart Association, Australian Dietary Guidelines, Dietary Guidelines for Americans, Institute of Medicine Dietary Reference Intake, Public Health England Government Dietary Recommendations, WHO Healthy Diet and the Paralyzed Veterans of America (PVA) Clinical Practice Guidelines. We also provide practical assessment and nutritional recommendations to facilitate a healthy dietary pattern after SCI. Because of a lack of strong SCI research, there are currently limited dietary recommendations outside of the PVA guidelines that capture the unique nutrient needs after SCI. Future multicentre clinical trials are needed to develop comprehensive, evidence-based dietary reference values specific for persons with SCI across the care continuum that rely on accurate, individual assessment of energy need.

Measured vs Predicted Energy Expenditure in Mechanically Ventilated Adults With Acute, Traumatic Spinal Cord Injuries

BACKGROUND

Research regarding the impact of acute spinal cord injury (aSCI) on energy expenditure is limited. Patients with aSCI are prone to complications of both over- and under-feeding, making appropriate nutrition support pivotal to patient care. The purpose of this study was to describe energy expenditure and assess the performance of predictive equations in mechanically ventilated adults with aSCI.

METHODS

Adult patients admitted to a single trauma center from March 2017 through June 2018 with aSCI and a documented indirect calorimetry (IC) within 6 weeks of injury were included for analysis. Predictive equations evaluated included Penn State 2003b (PS 2003b), the derived Weir equation, 25 kcal/kg and 30 kcal/kg. Sub-set analysis was performed for patients with and without obesity, isolated aSCI, and concomitant traumatic injuries.

RESULTS

On hundres fifteen IC studies in 51 patients were included for analysis. Median energy expenditure was 1747 kcal/day (interquartile range [IQR], 1492-2099 kcal/day), or 22.7 kcal/kg (IQR, 19.3-25.9 kcal/kg). When stratified by hospital day, energy expenditure ranged from 20 to 25 kcal/kg. PS 2003b and the derived Weir equation had similar correlation coefficients (r = 0.81 and 0.82, respectively). The 25 and 30 kcal/kg performed unacceptably (r = 0.61). PS 2003b predicted within 10% of measured energy expenditure most frequently. All equations were biased towards overfeeding, except for PS 2003b in the obese subset.

CONCLUSION

In the absence of IC, PS 2003b or the derived Weir equation may be acceptable predictive equations in this population. However, bedside clinicians should monitor carefully for signs and symptoms of overfeeding.

An observational study of feeding practice in ventilated patients with spinal cord injury

BACKGROUND AND AIMS

Cervical spinal cord injuries (CSCI) are frequently complicated by respiratory failure requiring prolonged invasive mechanical ventilation in the intensive care unit (ICU). Providing adequate nutrition may be an important factor in the recovery of respiratory muscle function for ventilator weaning. The aim of this study was to examine the practical implementation of a multi-disciplinary approach to nutrition combining indirect calorimetry and the modified Harris Benedict equation to achieve target rates of nutrition for patients with CSCI.

MATERIALS AND METHODS

A retrospective observational study was performed by collecting data of normal nutrition practice in a series of adult ventilated patients with CSCI admitted between 2014 and 2017 to the ICU. Administered calories by enteral nutrition and measured total energy expenditure (TEE) by indirect calorimetry were recorded for the first 3-weeks. Calculations were performed to measure the adequacy of calorie administration relative to TEE. Average daily temperatures and minute ventilation were recorded to support evidence for hypermetabolism. TEE estimates using the modified Harris Benedict equation were compared to indirect calorimetry measures for each patient.

RESULTS

Sixteen patients were included in the study. Calorie administration rapidly increased to a plateau of 2300-2400 kcal per day over the first four days. The median measured TEE by indirect calorimetry was initially high, starting at 3472 kcal/day and decreasing to 2784 kcal/day at three weeks. However, there was wide variation in energy expenditure amongst patients. Average daily temperatures and minute ventilation were high supporting hypermetabolism. Adequacy of calorie administration to TEE ranged between 76 and 86 percent through the study period. There was relatively wide variation when comparing estimates of TEE using the modified Harris Benedict equation versus indirect calorimetry.

CONCLUSIONS

A multi-disciplinary approach to nutrition in ventilated patients with CSCI, incorporating indirect calorimetry, achieves target rates of nutrition. Our findings suggest that a hypermetabolic response may be common but variable in this population and subsequently both under and over feeding may be a risk if nutrition targets are not guided by indirect calorimetry. Further prospective research using protocoled indirect calorimetry measures would be beneficial to ascertain accurate energy requirements for this group of patients and also determine whether feeding to target influences weaning off the ventilator.

Nutritional Alterations Associated with Neurological and Neurosurgical Diseases

Neurological and neurosurgical diseases lead to complications producing malnutrition increasing pathology and mortality. In order to avoid complications because of malnutrition or overcome deficiencies in nutrients supplements are often used for these subjects. The physiopathological mechanisms of malnutrition, methods of nutritional assessment and the supplemental support are reviewed in this paper based on the assumption that patients need to receive adequate nutrition to promote optimal recovery, placing nutrition as a first line treatment and not an afterthought in the rehabilitation.

Malnutrition in spinal cord injury: more than nutritional deficiency

Denervation of the spinal cord below the level of injury leads to complications producing malnutrition. Nutritional status affects mortality and pathology of injured subjects and it has been reported that two thirds of individuals enrolled in rehabilitation units are malnourished. Therefore, the aim should be either to maintain an optimal nutritional status, or supplement these subjects in order to overcome deficiencies in nutrients or prevent obesity. This paper reviews methods of nutritional assessment and describes the physiopathological mechanisms of malnutrition based on the assumption that spinal cord injured subjects need to receive adequate nutrition to promote optimal recovery, placing nutrition as a first line treatment and not an afterthought in the rehabilitation of spinal cord injury.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): patient with polytrauma]

Patients with polytrauma can be viewed as paradigmatic of the critically-ill patient. These previously healthy patients undergo a life-threatening aggression leading to an organic response that is no different from that in other types of patients. The profile of trauma patients has changed and currently corresponds to patients who are somewhat older, with a higher body mass index and greater comorbidity. Severe injuries lead to intense metabolic stress, posing a risk of malnutrition. Therefore, early nutritional support, preferentially through the enteral route, with appropriate protein intake and glutamine supplementation, provides advantages over other routes and types of nutritional formula. To avoid overnutrition, reduced daily calorie intake can be considered in obese patients and in those with medullary lesions. However, little information on this topic is available in patients with medullary lesions.

The ratio of energy expenditure to nitrogen loss in diverse patient groups--a systematic review

BACKGROUND & AIMS

The ratio of energy expenditure to nitrogen loss respectively of energy to nitrogen provision (E/N) is considered a valuable tool in the creation of an enteral or parenteral formulation. Specific E/N ratios for parenteral nutrition (PN) have not yet been clearly defined. To determine the range of energy expenditure, nitrogen (protein) losses, and E/N ratios for various patient groups, we performed a systematic review of the literature.

METHODS

Medline 1950-2011 was searched for all studies on patients or healthy controls reporting energy expenditure and nitrogen loss at the same time.

RESULTS

We identified 53 studies with 91 cohorts which comprised 1107 subjects. Mean TEE ± standard deviation (SD) was 31.2 ± 7.2 kcal/kg BW/day in patients (n = 881) and 35.6 ± 4.3 kcal/kg BW/day in healthy controls (n = 266). Mean total protein loss (TPL) was 1.50 ± 0.57 g/kg BW/day in patients and 0.94 ± 0.24 g/kg BW/day in healthy controls. A non-linear significant correlation was found between TPL and the E/N ratio.

CONCLUSION

The E/N ratio is not a constant value but decreases continuously with increasing protein loss. These variations should be considered in the nutritional support of patients.

Hypocaloric considerations in patients with potentially hypometabolic disease States

The provision of nutrition has traditionally been driven by the desire to provide adequate calories. However, over the past decade it has become evident that provision of excess calories can be detrimental to patients' outcomes in both critical care and long-term care settings. This review examines patient populations for whom hypocaloric nutrition can be both appropriate and beneficial. In specific situations, critically ill patients, such as those with obesity, stroke, and spinal cord injury, may have decreased energy requirements. In patients with spinal cord injury, the level of injury significantly correlates with the extent of reduced caloric energy expenditure. Ventilator-dependent patients with amyotrophic lateral sclerosis (ALS) have decreased energy needs; energy expenditure for ALS patients is lower than the predictive equation value. Aging patients will have decreased energy needs relative to a reduction in lean body mass. Patients with cerebral palsy (CP) have significantly lower caloric requirements than anticipated using predictive equations. Patients with CP pose a particular challenge in nutrition assessment. Several studies demonstrate that patients with CP have significantly lower caloric requirements than anticipated using predictive equations; thus, patients with CP benefit from indirect calorimetry. Provision of nutrition for obese patients is briefly addressed, as this is an increasingly important consideration for nutrition support in both the critical care and long-term care settings. When indirect calorimetry is not available, clinicians should remember that most patients will have low resting energy expenditure regardless of functional status and require frequent evaluation during institution of nutrition recommendations to guard against overfeeding and obesity.

Acute management of nutritional demands after spinal cord injury

A systematic review of the literature was performed to address pertinent clinical questions regarding nutritional management in the setting of acute spinal cord injury (SCI). Specific metabolic challenges are present following spinal cord injury. The acute stage is characterized by a reduction in metabolic activity, as well as a negative nitrogen balance that cannot be corrected, even with aggressive nutritional support. Metabolic demands need to be accurately monitored to avoid overfeeding. Enteral feeding is the optimal route following SCI. When oral feeding is not possible, nasogastric, followed by nasojejunal, then by percutaneous endoscopic gastrostomy, if necessary, is suggested.

Plasma precursors of brain catecholaminergic and serotonergic neurotransmitters in rehabilitation patients with ischemic stroke11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To determine levels of plasma amino acid tyrosine and tryptophan, precursors of brain catecholamine and serotonin neurotransmitters, respectively, in rehabilitative patients with ischemic stroke.

DESIGN

Controlled, pre-post analysis, consecutive sample.

SETTING

Rehabilitation center.

PARTICIPANTS

Twenty men with ischemic stroke (age, 68+/-11.3y) consecutively admitted into rehabilitation 15+/-10 days (range, 7-28d) after an acute cerebrovascular insult; 15 healthy sedentary subjects (controls 1); and 13 healthy hypoactive individuals who had recently had knee arthroplasty (controls 2). Both control groups were matched to stroke subjects for age, gender, and body weight.

INTERVENTIONS

At 8:00 am, after overnight fasting, venous blood samples were drawn from patients to determine plasma tyrosine and tryptophan levels. A nutritional evaluation, including nitrogen balance, was made. The same procedures were repeated after 45 days of rehabilitation. Amino acid data were compared with those obtained from the controls.

MAIN OUTCOME MEASURE

Plasma concentrations of amino acids.

RESULTS

Patients with ischemic stroke, on admission, had lower plasma tyrosine concentration than did both controls 1 (P<.0005) and controls 2 (P<.001), but a similar tryptophan level. The plasma content of tyrosine was similar between the 2 control groups. After 45 days of rehabilitation, the stroke patients' tyrosine and tryptophan levels remained virtually unchanged, as did nutritional parameters. Nutritional intakes were adequate to meet body needs but insufficient to correct plasma tyrosine.

CONCLUSIONS

Patients experiencing a recent stroke may have low plasma tyrosine levels and, therefore, reduced brain catecholamine formation. It is possible that an imbalance of brain neurotransmitters may occur.

Early versus late enteral feeding in patients with acute cervical spinal cord injury: a pilot study

STUDY DESIGN

A prospective randomized clinical pilot study to compare early versus late enteral feeding in patients with acute cervical spinal cord injury.

OBJECTIVES

To compare the incidence of infections in patients with acute cervical spinal cord injury who received early versus late enteral feeding. Secondary objectives included assessing nutritional status, feeding tolerance, the number of ventilator hours, and acute-care hospital length of stay.

SUMMARY OF BACKGROUND DATA

Early nutritional support has been found to be beneficial in critically ill patients. However, the same benefits may not be realized in patients with acute cervical spinal cord injury because of their unique nutritional challenges.

METHODS

Eligible patients were randomized to early feeding (initiated before 72 hours after injury) and late (initiated more than 120 hours after injury). Patients were stratified on the basis of their neurologic level. Patients were assessed daily for the first 15 days. After that time, infections (according to Center for Disease Control criteria), ventilator hours, and length of acute-care hospital stay were tracked.

RESULTS

Twenty-three patients met the eligibility criteria, and 17 patients were included in the analysis. There were 7 patients in the early group and 10 in the late group. The early group had a mean of 2.4 +/- 1.5 infections compared with the late group, which had a mean of 1.7 +/- 1.1 infections. Secondary outcomes were not substantially different between the two groups.

CONCLUSIONS

This pilot study failed to detect any differences in the incidence of infection, nutritional status, feeding complications, number of ventilator hours, or length of stay between patients receiving early versus late initiation of enteral feeding. These data will assist in the determination of an adequate sample size for future studies.

Reduced plasma levels of tyrosine, precursor of brain catecholamines, and of essential amino acids in patients with severe traumatic brain injury after rehabilitation11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To investigate whether levels of plasma tyrosine and tryptophan, precursors of brain catecholamine and serotonin neurotransmitters, respectively, and other essential amino acids (EAA) may return to normal in patients with severe traumatic brain injury (TBI) after 2 months in a hospital rehabilitation center.

DESIGN

Peripheral plasma concentrations of tyrosine, tryptophan, and other EAAs in subjects with severe TBI, both at admission (44+/-11d postinjury) and at discharge from the center (110+/-15d after acute event) were compared with concentrations in control subjects.

SETTING

Tertiary care rehabilitation setting in Italy.

PARTICIPANTS

Ten men (26.6+/-12.6y) with TBI and 6 healthy subjects (controls) matched for age, sex, voluntary loss of body weight, and sedentary lifestyle.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Concentrations of brain neurotransmitter precursor amino acids and of EAA.

RESULTS

On admission, patients had lower plasma tyrosine, leucine, valine, methionine, and phenylalanine concentrations than did control subjects. The plasma concentrations of tryptophan were similar in the 2 groups. These amino acid abnormalities were still present at discharge.

CONCLUSION

The levels of plasma tyrosine and many EAA in patients with TBI did not recover by discharge (110+/-15d) from rehabilitation. Plasma tryptophan concentrations were similar in patients and controls.

Peripheral plasma amino acid abnormalities in rehabilitation patients with severe brain injury

OBJECTIVE

Acute severe brain injury causes an increased mobilization of amino acids from tissue. The plasma amino acid profile of patients undergoing rehabilitation after brain injury is unknown. This study was aimed at delineating the plasma amino acid profile of rehabilitation patients with brain injury.

DESIGN

Peripheral plasma aminogram, lactate, pyruvate, glycerol, ketone body, and carnitine concentrations were determined in 11 patients with brain injury (34.6+/-15 years old, 60+/-16.8 days after injury) and in 8 controls. Resting energy expenditure and nitrogen balance were also determined.

RESULTS

(1) All essential amino acids and about 50% of nonessential amino acids were significantly lower in brain injury patients than in controls (p < .05). (2) Plasma amino acids were lower irrespective of either energy and protein intake or nitrogen balance. (3) Total carnitine concentration and esterified/free carnitine ratio were higher in brain injury patients than in controls (p < .05).

CONCLUSIONS

Rehabilitation patients with brain injury may have an important reduction of their plasma aminogram. Muscle tissue depletion and the persistence of a hypercatabolic state caused by subclinical infections, pressure sores, and immobility may contribute to this reduction.

Metabolic assessment and enteral tube feeding usage in children with acute neurological diseases

OBJECTIVE

To report on acquired experience of metabolic support for children with acute neurological diseases, emphasizing enteral tube feeding usage and metabolic assessment, and also to recommend policies aimed towards improving its implementation.

DESIGN

Retrospective analysis.

SETTING

Pediatric Intensive Care Unit of Hospital do Servidor Público Estadual de São Paulo.

SUBJECTS

44 patients consecutively admitted to the Pediatric ICU over a period of 3 years who were given nutrition and metabolic support for at least 72 hours. Head trauma, CNS infections and craniotomy post-operative period following tumor exeresis were the main diagnoses.

MEASUREMENTS

Records of protein-energy intake, nutrient supply route, nitrogen balance and length of therapy.

RESULTS

From a total of 527 days of therapy, single parenteral nutrition was utilized for 34.3% and single enteral tube feeding for 79.1% of that period. 61.4% of the children were fed exclusively via enteral tube feeding, 9.1% via parenteral and 39.5% by both routes. The enteral tube feeding was introduced upon admission and transpyloric placement was successful in 90% of the cases. Feeding was started 48 hours after ICU admission. The caloric goal was achieved on the 7th day after admission, and thereafter parenteral nutrition was interrupted. The maximum energy supply was 104.2 +/- 23.15 kcal/kg. The median length of therapy was 11 days (range 4-38). None of the patients on tube feeding developed GI tract bleeding, pneumonia or bronchoaspiration episodes and, of the 4 patients who were given exclusive TPN, 2 developed peptic ulcer. The initial urinary urea nitrogen was 7.11 g/m2 and at discharge 6.44 g/m2. The protein supply increased from 1.49 g/kg to 3.65 g/kg (p < 0.01). The nitrogen balance increased from--7.05 to 2.2 g (p < 0.01).

CONCLUSIONS

Children with acute neurological diseases are hypercatabolic and have high urinary nitrogen losses. The initial negative nitrogen balance can be increased by more aggressive feeding regimes than the usual ones. Early tube feeding was well tolerated, which permits the conclusion that it is a safe and effective method for nutrition support. Recommendations of basic rules for metabolic support are made.

[Nutritional aspects of cranial trauma]

In head-injured patients the nutritional support is aimed to prevent denutrition status usually observed. The adequate amount of calories depends on the basal metabolism (as calculated with the Harris Benedict equation). It has to be increased in case of fever (by a 0.1 factor per degree above 37 degrees C), sepsis (by a 0.1 to 0.2 factor) or when sedation is discontinued (by a 0.3 factor). The increased proteolysis is not modified by the associated treatment and results in an inevitable protein loss, whatever the qualitative change in nutritional support. In clinical practice, the nutritional support has to be adjusted continuously to the needs of the patient, to avoid a more pronounced denutrition due to the summation of daily nutritional deficits.

Observations on the patterns of 24-hour energy expenditure changes in body composition and gastric emptying in head-injured patients receiving nasogastric tube feeding

BACKGROUND

Although intolerance to nasogastric feeding is commonly observed after head injury, quantitative measurements of gastric emptying are lacking. Concepts about energy requirements are limited by the lack of long-term measurements of total energy expenditure.

METHODS

Six male subjects with severe head injury had their gastric emptying measured by the phenol red technique. N and energy balances were measured by classic balance techniques, which included continuous indirect calorimetry for up to 24 hours (days 3 to 5). Measurements of body composition were made on days 3 to 5 and 12 to 19 (4 subjects only).

RESULTS

The subjects lost a mean of 9.8 kg of which 2.3 kg was estimated to be due to fat (equivalent to -14 g N/d and -1690 kcal/d). On days 3 to 5, basal metabolic rate (BMR) was 130% to 135% of predicted. The low dietary intake (650 kcal and 4.2g N/d) was associated with negative energy (-1710 +/- 520 kcal/d) and N balances (-19 +/- 5 g N/d). Gastric emptying was delayed twofold (days 3 to 5) compared with controls (p < .001) and was associated with significant regurgitation of feed into the mouth (16 of 31 saliva samples contained glucose at a concentration of > 0.5 mmol/L compared with control values of < 0.2 mmol/L.

CONCLUSIONS

The large negative energy balance in the subjects studied was largely due to the inadequate nasogastric feeding, which was associated with a twofold reduction in the rate of gastric emptying and frequent regurgitation of feed. The large negative N balance and the high contribution of protein oxidation to total energy expenditure (25% to 28%) was predominantly due to the injury sustained and immobility. An increase in BMR is not necessarily associated with increased total energy expenditure or energy requirements.

Bleeding stress and metabolic changes in the crab Scylla tranquebarica (Fabricius)

In the crab scylla tranquebarica, bleeding stress is characterized by changes in proteins, lactic acid and water content of muscles, hepatopancreas and haemolymph. Proteins seemed to be involved in energy expenditure and internal osmotic balance. Lactate levels increased, suggesting a shift in aerobic metabolism. Water content fell.

Immediate enteral nutrition following multisystem trauma: a decade perspective

Metabolic support is an integral component of surgical critical care. Although prompt restoration of oxygen availability is clearly essential, the timing, composition, and route of nutritional support may also be decisive factors. The ensuing discussion will focus on: (a) timing of substrate delivery and (b) route of administration based on our clinical investigation over the past decade. The acutely injured patient was selected as a model of ICU hypermetabolism because of relative homogeneity with respect to age, comorbid factors, and stress level. Our first study hypothesis was that early nutritional support would improve outcome in the severely injured, but previously well-nourished patient. During an 18-month period, all patients undergoing laparotomy with a abdominal trauma index (ATI) greater than 15 were randomized to a control or total enteral nutrition (TEN) group. The control patients were given total parenteral nutrition (TPN) after POD 5, whereas the TEN cohort had a needle catheter jejunostomy (NCJ) inserted at laparotomy and received an elemental diet within 12 hours. The control (n = 31) and TEN (n = 32) groups were otherwise comparable with respect to risk stratification. The TEN patients, of course, shared improved nitrogen balance (p less than 0.001), but also had significantly (p less than 0.025) less septic morbidity. Nine (29%) of the controls developed major infections, contrasted to three (9%) of the TEN patients. Acknowledging the benefit of early nutrition, the next issue we addressed was the optimal route of substrate delivery; i.e., TEN vs TPN. The hypothesis was that TEN, compared to TPN, would reduce the injury stress response as reflected by the prioritization of hepatic protein synthesis. TEN given via NCJ and a nutritionally matched TPN solution were administered during the same postoperative period. Indeed, the TEN patients (n = 23) had significantly (p less than 0.05) higher constitutive proteins and lower acute-phase proteins, whereas the TPN patients manifested the opposite protein profile as measured by crossed immunoelectrophoresis. In view of these findings, we continued the study to ascertain clinical impact. Ultimately, 75 patients were randomized, providing groups with equivalent risk factors. Eleven (37%) of the TPN patients developed septic complications compared to five (17%) of the TEN group, and the incidence of major infection was six (20%) following TPN vs one (3%) with TEN. Thus, immediate TEN provided an additional clinical benefit compared to early TPN in these high-risk surgical patients.

Obligatory negative nitrogen balance following spinal cord injury

Obligatory nitrogen losses due to paralysis in the spinal cord-injured (SCI) patient prevent positive nitrogen balance (NB) regardless of the calorie and protein intakes. Ten patients with SCI and 20 controls with nonspinal cord injury (NSCI) matched for time, sex, age, and injury severity score (ISS) were admitted to our Level I trauma center. In both groups, total nutritional support was delivered within 72 hours of admission based on predicted energy expenditures (PEE = Harris-Benedict equation x 1.2 x 1.6) and 2 g of protein/kg of ideal body weight (IBW). Subsequent changes in nutrient delivery were based on NB. No SCI patient established positive NB during the 7-week period following injury despite an average delivery of 2.4 g of protein/kg IBW and 120% of the PEE at the time of peak negative NB (-10.5). In six SCI patients, an average increase of 25% in delivered protein and 12% in delivered calories over a 1-week period effected no change in average NB (-7.4 vs -6.8). Indirect calorimetry in five SCI patients showed that calorie intakes were 110% more than average measured energy expenditures. In contrast, 17 of 20 NCSI patients achieved positive NB within 3 weeks of admission. They required an average delivery of 2.3 g of protein/kg IBW and 110% of PEE to reach positive NB. These data demonstrate the phenomenon of obligatory negative NB acutely following SCI. Aggressive attempts to achieve positive NB in these patients will fail and result in overfeeding.

Penetrating craniocerebral trauma

The authors review the pathophysiology of penetrating and perforating cranial wounds. Radiologic evaluation includes computed tomography and angiography. Operative technique and perioperative critical care are discussed, with special emphasis on the control of the intracranial pressure. Other problems such as fluid and electrolyte disorders and nutrition are discussed in relation to neurosurgery.