Metabolic and nutritional sequelae in the non-steroid treated head injury patient

Measuring Energy Requirements of Traumatic Brain Injury Patients in Pediatric Intensive Care With Indirect Calorimetry: A Comparison With Empiric Methods

OBJECTIVES

Energy requirements following moderate or severe pediatric traumatic brain injury (TBI) have not been fully elucidated. Indirect calorimetry (IC) is the gold standard for measuring resting energy expenditure (MREE) in PICU. However, technical complexity limits its use. We aimed to determine whether MREE differs from standard of care energy estimation and delivery in a cohort of pediatric patients following moderate to severe TBI during PICU admission.

DESIGN

Retrospective case series study.

SETTING

Single-center, 16-bed general PICU in Canada between May 2011 and January 2019.

PATIENTS

Children (0-18 yr) admitted to a PICU for moderate (Glasgow Coma Scale [GCS] 9-12) to severe TBI (GCS < 9) and had an IC study performed while mechanically ventilated.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During the study period, 245 patients were admitted with the diagnosis of trauma with TBI. The study includes a convenience sample of 26 patients with severe ( n = 23) and moderate ( n = 3) TBI who underwent a total of 34 IC measurements. MREE varied considerably from 29% to 144% of predicted energy expenditure. Using Bland-Altman comparative analysis, neither Schofield nor World Health Organization predictive equations were in agreement with MREE. Only one measurement revealed that the patient was appropriately fed (energy provided in nutrition support was within 10% of MREE); 10 (38%) measurements revealed overfeeding and 15 (58%) underfeeding at the time of testing.

CONCLUSIONS

The present study adds to the small body of literature highlighting the limitations of predictive equations to evaluate energy requirements following moderate to severe pediatric TBI. IC, when feasible, should be used as the preferred method to orient PICU teams to feed such vulnerable patients.

Evaluation of Electrolyte Imbalance in Patients With Traumatic Brain Injury Admitted in the Central ICU of a Tertiary Care Centre: A Prospective Observational Study

Introduction Electrolyte imbalance is a salient finding in traumatic brain injury which can derail their clinical course of recovery in physical and cognitive health while prolonging the hospital stay. Objective This study aims to understand the variation in electrolyte profile that occurs in traumatic brain injury patients which can help in better patient management. Materials and method 50 trauma patients with head injury (Group A) and 50 patients without head injury (Group B) admitted in Central ICU (CICU) under the Department of Anaesthesiology, Assam Medical College and Hospital (AMCH) were selected and analysed with regard to their electrolyte variability. Result All trauma patients with head injury developed an imbalance to one or more electrolytes. Then mean electrolyte level in trauma patients with a head injury and in trauma patients without head injury were 139.3±7.45 vs 143.65±8.89, p<0.05 (sodium), 3.49±0.44 vs 3.88±0.49, p<0.05 (potassium), 7.81±0.5 vs 8.9± 0.35, p<0.05 (calcium) and 2±0.33 vs 2.47±0.41, p<0.05 (magnesium) respectively. Also, patients in the head injury group had a higher incidence of hypoalbuminemia than patients without head injury 2.47±0.67 vs 2.83±0.74 (p<0.05). Conclusion We conclude that traumatic brain injury patients have a greater risk of electrolyte imbalance, viz. hyponatremia, hypokalaemia, hypocalcaemia as well as hypomagnesemia, and hypophosphatemia along with hypoalbuminemia.

Whole-Body Metabolism, Carbohydrate Utilization, and Caloric Energy Balance After Sport Concussion: A Pilot Study

BACKGROUND

Sport concussion (SC) causes an energy crisis in the brain by increasing energy demand, decreasing energy supply, and altering metabolic resources. Whole-body resting metabolic rate (RMR) is elevated after more severe brain injuries, but RMR changes are unknown after SC. The purpose of this study was to longitudinally examine energy-related changes in collegiate athletes after SC.

HYPOTHESIS

RMR and energy consumption will increase acutely after SC and will return to control levels with recovery.

STUDY DESIGN

Case-control study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 20 collegiate athletes with SC (mean age, 19.3 ± 1.08 years; mean height, 1.77 ± 0.11 m; mean weight, 79.6 ± 23.37 kg; 55% female) were compared with 20 matched controls (mean age, 20.8 ± 2.17 years; mean height, 1.77 ± 0.10 m; mean weight, 81.9 ± 23.45 kg; 55% female). RMR, percentage carbohydrate use (%CHO), and energy balance (EBal; ratio between caloric consumption and expenditure) were assessed 3 times: T₁, ≤72 hours after SC; T₂, 7 days after T₁; and T_F, after symptom resolution. A 2 × 2 × 3 (group × sex × time) multivariate analysis of variance assessed RMR, %CHO, and EBal. Changes in RMR, %CHO, and EBal (T₁ to T_F) were correlated with days to symptom-free and days to return to play in the concussed group.

RESULTS

Women reported being symptom-free (median, 6 days; range, 3-10 days) sooner than men (median, 11 days; range, 7-16 days). RMR and %CHO did not differ across time between groups or for group × sex interaction. SC participants had higher EBal than controls at T₁ (P = 0.016) and T₂ (P = 0.010). In men with SC, increasing %CHO over time correlated with days to symptom-free (r = 0.735 and P = 0.038, respectively) and days to return to play (r = 0.829 and P = 0.021, respectively).

CONCLUSION

Participants with SC were in energy surplus acutely after injury. Although women recovered more quickly than men, men had carbohydrate metabolism changes that correlated with recovery time.

CLINICAL RELEVANCE

This pilot study shows that male and female student-athletes may have differing physiologic responses to SC and that there may be a role for dietary intervention to improve clinical outcomes after SC.

Early enteral nutrition in patients with severe traumatic brain injury: a propensity score-matched analysis using a nationwide inpatient database in Japan

BACKGROUND

Whether enteral nutrition (EN) should be administered early in severe traumatic brain injury (TBI) patients has not been fully addressed.

OBJECTIVE

The present study aimed to evaluate whether early EN can reduce mortality or nosocomial pneumonia among severe TBI patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from April 2014 to March 2017 linked with the Survey for Medical Institutions, we identified patients admitted for intracranial injury with Japan Coma Scale scores ≥30 (corresponding to Glasgow Coma Scale scores ≤8) at admission. We designated patients who started EN within 2 d of admission as the early EN group, and those who started EN at 3-5 d after admission as the delayed EN group. The primary outcome was in-hospital mortality. The secondary outcome was nosocomial pneumonia. Propensity score-matched analyses were performed to compare the outcomes between the 2 groups.

RESULTS

We identified 3080 eligible patients during the 36-mo study period, comprising 1100 (36%) in the early EN group and 1980 (64%) in the delayed EN group. After propensity score matching, there was no significant difference in in-hospital mortality (difference: -0.3%; 95% CI: -3.7%, 3.1%) between the 2 groups. The proportion of nosocomial pneumonia was significantly lower in the early EN group than in the delayed EN group (difference: -3.2%; 95% CI: -5.9%, -0.4%).

CONCLUSIONS

Early EN may not reduce mortality, but may reduce nosocomial pneumonia in patients with severe TBI.

Nutritional and Bioenergetic Considerations in Critically Ill Patients with Acute Neurological Injury

The brain, due to intensive cellular processes and maintenance of electrochemical gradients, is heavily dependent on a constant supply of energy. Brain injury, and critical illness in general, induces a state of increased metabolism and catabolism, which has been proven to lead to poor outcomes. Of all the biochemical interventions undertaken in the ICU, providing nutritional support is perhaps one of the most undervalued, but potentially among the safest, and most effective interventions. Adequate provisions of calories and protein have been shown to improve patient outcomes, and guidelines for the nutritional support of the critically ill patient are reviewed. However, there are no such specific guidelines for the critically ill patient with neurological injury. Patients with primary or secondary neurological disorders are frequently undernourished, while data suggest this population would benefit from early and adequate nutritional support, although comprehensive clinical evidence is lacking. We review the joint recommendations from the Society for Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition, as they pertain to neurocritical care, and assess the recommendations for addressing nutrition in this patient population.

Initiating Nutritional Support Before 72 Hours Is Associated With Favorable Outcome After Severe Traumatic Brain Injury in Children: A Secondary Analysis of a Randomized, Controlled Trial of Therapeutic Hypothermia

OBJECTIVES

To understand the relationship between the timing of initiation of nutritional support in children with severe traumatic brain injury and outcomes.

DESIGN

Secondary analysis of a randomized, controlled trial of therapeutic hypothermia (Pediatric Traumatic Brain Injury Consortium: Hypothermia, also known as "the Cool Kids Trial" (NCT 00222742).

SETTINGS

Fifteen clinical sites in the United States, Australia, and New Zealand.

SUBJECTS

Inclusion criteria included 1) age less than 18 years, 2) postresuscitation Glasgow Coma Scale less than or equal to 8, 3) Glasgow Coma Scale motor score less than 6, and 4) available to be randomized within 6 hours after injury. Exclusion criteria included normal head CT, Glasgow Coma Scale equals to 3, hypotension for greater than 10 minutes (< fifth percentile for age), uncorrectable coagulopathy, hypoxia (arterial oxygen saturation < 90% for > 30 min), pregnancy, penetrating injury, and unavailability of a parent or guardian to consent at centers without emergency waiver of consent.

INTERVENTIONS

Therapeutic hypothermia (32-33°C for 48 hr) followed by slow rewarming for the primary study. For this analysis, the only intervention was the extraction of data regarding nutritional support from the existing database.

MEASUREMENTS AND MAIN RESULTS

Timing of initiation of nutritional support was determined and patients stratified into four groups (group 1-no nutritional support over first 7 d; group 2-nutritional support initiated < 48 hr after injury; group 3-nutritional support initiated 48 to < 72 hr after injury; group 4-nutritional support initiated 72-168 hr after injury). Outcomes were also stratified (mortality and Glasgow Outcomes Scale-Extended for Pediatrics; 1-4, 5-7, 8) at 6 and 12 months. Mixed-effects models were performed to define the relationship between nutrition and outcome. Children (n = 90, 77 randomized, 13 run-in) were enrolled (mean Glasgow Coma Scale = 5.8); the mortality rate was 13.3%. 57.8% of subjects received hypothermia Initiation of nutrition before 72 hours was associated with survival (p = 0.01), favorable 6 months Glasgow Outcomes Scale-Extended for Pediatrics (p = 0.03), and favorable 12 months Glasgow Outcomes Scale-Extended for Pediatrics (p = 0.04). Specifically, groups 2 and 3 had favorable outcomes versus group 1.

CONCLUSIONS

Initiation of nutritional support before 72 hours after traumatic brain injury was associated with decreased mortality and favorable outcome in this secondary analysis. Although this provides a rationale to initiate nutritional support early after traumatic brain injury, definitive studies that control for important covariates (severity of injury, clinical site, calories delivered, parenteral/enteral routes, and other factors) are needed to provide definitive evidence on the optimization of the timing of nutritional support after severe traumatic brain injury in children.

Effects of immunonutrition on biomarkers in traumatic brain injury patients in Malaysia: a prospective randomized controlled trial

Background

Head injury is one of the top three diagnosis leading to intensive care unit (ICU) admission in Malaysia. There has been growing interest in using immunonutrition as a mode of modulating the inflammatory response to injury or infection with the aim of improving clinical outcome. The aim of the present study was to evaluate the effect of an immunonutrition on biomarkers (IL-6, glutathione, CRP, total protein and albumin) in traumatic brain injury patients.

Methods

Thirty six patients with head injury admitted to neurosurgical ICU in University Malaya Medical Centre were recruited for this study, over a 6-month period from July 2014 to January 2015. Patients were randomized to receive either an immunonutrition (Group A) or a standard (Group B) enteral feed. Levels of biomarkers were measured at day 1, 5 and 7 of enteral feeding.

Results

Patients in Group A showed significant reduction of IL-6 at day 5 (p < 0.001) with concurrent rise in glutathione levels (p = 0.049). Patients in Group A also demonstrated a significant increase of total protein level at the end of the study (day 7).

Conclusion

These findings indicate the potential of immunonutrition reducing cytokines and increasing antioxidant indices in patients with TBI. However, further studies incorporating patient outcomes are needed to determine its overall clinical benefits.

Trial registration

National Medical Research Register (NMRR) ID: 14–1430-23,171. ClinicalTrials.gov identifier: NCT03166449.

Meta-Analysis of Therapeutic Hypothermia for Traumatic Brain Injury in Adult and Pediatric Patients

OBJECTIVE

Therapeutic hypothermia has been used to attenuate the effects of traumatic brain injuries. However, the required degree of hypothermia, length of its use, and its timing are uncertain. We undertook a comprehensive meta-analysis to quantify benefits of hypothermia therapy for traumatic brain injuries in adults and children by analyzing mortality rates, neurologic outcomes, and adverse effects.

DATA SOURCES

Electronic databases PubMed, Google Scholar, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov and manual searches of studies were conducted for relevant publications up until February 2016.

STUDY SELECTION

Forty-one studies in adults (n = 3,109; age range, 18-81 yr) and eight studies in children (n = 454; age range, 3 mo to 18 yr) met eligibility criteria.

DATA EXTRACTION

Baseline patient characteristics, enrollment time, methodology of cooling, target temperature, duration of hypothermia, and rewarming protocols were extracted.

DATA SYNTHESIS

Risk ratios with 95% CIs were calculated. Compared with adults who were kept normothermic, those who underwent therapeutic hypothermia were associated with 18% reduction in mortality (risk ratio, 0.82; 95% CI, 0.70-0.96; p = 0.01) and a 35% improvement in neurologic outcome (risk ratio, 1.35; 95% CI, 1.18-1.54; p < 0.00001). The optimal management strategy for adult patients included cooling patients to a minimum of 33°C for 72 hours, followed by spontaneous, natural rewarming. In contrast, adverse outcomes were observed in children who underwent hypothermic treatment with a 66% increase in mortality (risk ratio, 1.66; 95% CI, 1.06-2.59; p = 0.03) and a marginal deterioration of neurologic outcome (risk ratio, 0.90; 95% CI, 0.80-1.01; p = 0.06).

CONCLUSIONS

Therapeutic hypothermia is likely a beneficial treatment following traumatic brain injuries in adults but cannot be recommended in children.

Management of Elevated Intracranial Pressure

Elevated intracranial pressure (ICP) is a primary cause of morbidity and mortality for many neurologic disorders. The relationship between ICP and brain volume is influenced by autoregulatory processes that can become dysfunctional. As a result, neurologic damage can occur by systemic and intracranial insults such as ischemia and excitatory amino acids. Therefore, survival is dependent on optimizing ICP and cerebral perfusion pressure. Treatment of intracranial hypertension requires intensive monitoring and aggressive therapy. Intracranial pressure monitoring techniques such as intraventricular catheters are useful for determining ICP elevations before changes in vital signs and neurologic status. Therapeutic modalities, generally aimed at reducing cerebral blood volume, brain tissue, and cerebrospinal fluid (CSF) volume, include nonpharmacologic (CSF removal, controlled hyperventilation, and elevating the patient’s head) and pharmacologic management. Mannitol and sedation are first-line agents used to lower ICP. Barbiturate coma may be beneficial in patients with elevated ICP refractory to conventional treatment. The use of prophylactic antiseizure therapy and optimal nutrition prevents significant complication. Currently, investigations are directed at discovering useful neuroprotective agents that prevent secondary neurologic injury.

Phenytoin Monitoring in the Intensive Care Unit

Phenytoin has been used extensively in the neurological and neurosurgical settings since its introduction in 1938. Despite the fact that alternative agents exist, including a whole series of newer agents, phenytoin is still considered one of the most effective, relatively nontoxic anticonvulsant therapies currently available. Unfortunately, however, the pharmacokinetics and pharmacodynamics of this drug are complex and often confuse the pharmacist and physician team, resulting in suboptimal or unacceptably high serum concentrations. This was exactly the case in our institution up until 3 years ago, when a major pharmacy-initiated education and dosing service program was implemented. We review the basic phenytoin monitoring guidelines used in our institution, which are substantiated by the current literature and by personal experience.

Energy expenditure in children after severe traumatic brain injury

OBJECTIVE

To evaluate energy expenditure in a cohort of children with severe traumatic brain injury.

DESIGN

A prospective observational study.

SETTING

A pediatric neurotrauma center within a tertiary care institution.

PATIENTS

Mechanically ventilated children admitted with severe traumatic brain injury (Glasgow Coma Scale < 9) with a weight more than 10 kg were eligible for study. A subset of children was co-enrolled in a phase 3 study of early therapeutic hypothermia. All children were treated with a comprehensive neurotrauma protocol that included sedation, neuromuscular blockade, temperature control, antiseizure prophylaxis, and a tiered-based system for treating intracranial hypertension.

INTERVENTIONS

Within the first week after injury, indirect calorimetry measurements were performed daily when the patient's condition permitted.

MEASUREMENTS AND MAIN RESULTS

Data from 13 children were analyzed (with a total of 32 assessments). Measured energy expenditure obtained from indirect calorimetry was compared with predicted resting energy expenditure calculated from Harris-Benedict equation. Overall, measured energy expenditure/predicted resting energy expenditure averaged 70.2% ± 3.8%. Seven measurements obtained while children were hypothermic did not differ from normothermic values (75% ± 4.5% vs 68.9% ± 4.7%, respectively, p = 0.273). Furthermore, children with favorable neurologic outcome at 6 months did not differ from children with unfavorable outcome (76.4% ± 6% vs 64.7% ± 4.7% for the unfavorable outcome, p = 0.13).

CONCLUSIONS

Contrary to previous work from several decades ago that suggested severe pediatric traumatic brain injury is associated with a hypermetabolic response (measured energy expenditure/predicted resting energy expenditure > 110%), our data suggest that contemporary neurocritical care practices may blunt such a response. Understanding the metabolic requirements of children with severe traumatic brain injury is the first step in development of rational nutritional support goals that might lead to improvements in outcome.

The prognostic significance of the timing of total enteral feeding in traumatic brain injury

BACKGROUND

To study the effect of timing of total enteral feeding on various nutritional parameters and neurological outcome in patients with severe traumatic brain injury (TBI).

METHODS

One hundred and fourteen patients, in the age group of 20-60 years, admitted within 24 h of TBI with Glasgow Coma Scale (GCS) 4-8 were enrolled for the study. Nineteen patients who had expired before the attainment of total enteral feeding were excluded from the analysis. Total enteral feeding was attained before 3 days, 4-7 days, and after 7 days in 12, 52, and 31 patients, respectively, depending on gastric tolerance. They were prospectively assessed for various markers of nutrition and outcome was assessed at 3 and 6 months.

RESULTS

Prospective assessment of 67 hospitalized patients at 3 weeks revealed significant differences in anthropometric measurements, total protein, albumin levels, clinical features of malnutrition, and mortality among the three groups. 80% of those fed before 3 days had favorable outcome at 3 months compared to 43% among those fed later. The odds ratio (OR) was 5.29 (95% CI 1.03-27.03) and P value was 0.04. The difference between those fed before 3 days and 4-7 days was not significant at 6 months even though patients fed before 7 days had still significantly higher favorable outcome compared to those fed after 7 days (OR 7.69, P = 0.002). Multivariate analysis for unfavorable outcome showed significance of P = 0.03 for feeding after 3 days and P = 0.01 for feeding after 7 days.

CONCLUSIONS

In severe TBI, unfavorable outcome was significantly associated with attainment of total enteral feeding after 3 days and more so after 7 days following injury.

Effect of early compared with delayed enteral nutrition on endocrine function in patients with traumatic brain injury: an open-labeled randomized trial

BACKGROUND

Traumatic brain injury (TBI) results in a hypermetabolic and hypercatabolic status in which adequate nutrition support is essential to improve clinical outcome. The endocrine system of a patient with TBI is also affected and may play a critical role in either the metabolic or the immunologic response to the trauma. In the present study, the effect of standard, delayed enteral feeding (DEF), compared with early (within 24-48 hours) enteral feeding (EEF), on the endocrine function of patients with TBI was investigated.

METHODS

This comparative, prospective, open-labeled, randomized study included TBI patients admitted to the intensive care unit (ICU). Injury severity was assessed by the Glasgow Coma Scale and predicted mortality by the Acute Physiology and Chronic Health Evaluation II. Twenty-five patients received DEF and 34 patients received EEF. The effect of the onset of nutrition on pituitary, thyroidal, gonadal, and adrenal function was investigated on days 6 and 12 after admission to the hospital.

RESULTS

Levels of thyroid-stimulating hormone, free triiodothyronine, free thyroxine, and testosterone (in males) of DEF patients declined in comparison to levels of the day of admission to the ICU. The decrease of hormonal values was less pronounced in the EEF group. Cortisol concentrations rose in the DEF group; a lesser hormonal change was found in the EEF group. Deaths during the study for the DEF group and EEF group were 2 and 3, respectively.

CONCLUSIONS

EEF may exert beneficial effects on the hormonal profile of TBI patients, possibly contributing to a better clinical outcome in this patient group.

Nutrition support of the traumatically injured warfighter

Major trauma induces metabolic alterations that contribute to the systemic immune suppression in severely injured patients and increase the risk of infection and posttraumatic organ failure. Nutrition modulation of cellular processes has evolved into a high-priority therapy, backed by substantial scientific evidence. The appropriate selection, timing, and dose of nutrients required for metabolic resuscitation must be individualized and goal directed. Ideally, the nutritional interventions for warfighters will be developed strategically based on the extent of injuries and underlying deficiencies and will be designed to provide the nutrients necessary to balance hypermetabolic processes, heal wounds, and promote optimal recovery.

Systemic metabolic effects of combined insulin-like growth factor-I and growth hormone therapy in patients who have sustained acute traumatic brain injury

OBJECT

Hypermetabolism, hypercatabolism, refractory nitrogen wasting, hyperglycemia, and immunosuppression accompany traumatic brain injury (TBI). Pituitary dysfunction occurs, affecting growth hormone (GH) and plasma insulin-like growth factor-I (IGF-I) concentrations. The authors evaluated whether combination IGF-I/GH therapy improved metabolic and nutritional parameters after moderate to severe TBI.

METHODS

The authors conducted a prospective, randomized, double-blind study comparing combination IGF-I/GH therapy and a placebo treatment. Ninety-seven patients with TBI were enrolled in the study within 72 hours of injury and were assigned to receive either combination IGF-I/GH therapy or placebo. All patients received concomitant nutritional support. Insulin-like growth factor-I was administered by continuous intravenous infusion (0.01 mg/kg/hr), and GH (0.05 mg/kg/day) was administered subcutaneously. Placebo control group patients received normal saline solution in place of both agents. Nutritional and metabolic monitoring continued throughout the 14-day treatment period. The two groups did not differ in energy expenditure, nutrient intake, or use of insulin treatment. The mean daily serum glucose concentration was higher in the treatment group (123 +/- 24 mg/dl) than in the control group (104 +/- 11 mg/dl) (p < 0.03). A positive nitrogen balance was achieved within the first 24 hours in the treatment group and remained positive in that group throughout the treatment period (p < 0.05). This pattern was not observed in the control group. Plasma IGF-I concentrations were above 350 ng/ml in the treatment group throughout the study period. Overall, the mean plasma IGF-I concentrations were 1003 +/- 480.6 ng/ml in the treatment group and 192 +/- 46.2 ng/ml in the control group (p < 0.01).

CONCLUSIONS

The combination of IGF-I and GH produced sustained improvement in metabolic and nutritional endpoints after moderate to severe acute TBI.

Effect of an immune-enhancing diet on lymphocyte in head-injured rats: What is the role of arginine?

OBJECTIVE

The benefit of immune-enhancing diets (IEDs) in the intensive care unit remains controversial. Considering their complexity, the role of each component, in particular arginine (Arg), in their properties is largely unknown. The aim of this study was to determine the role of arginine in the immunomodulatory effects of an IED (Crucial) in head-injured rats.

DESIGN

Thirty-four rats were randomized into five groups: AL (ad libitum), HI (head-injured), HI-STD (HI + standard enteral nutrition, EN), HI-STD-Arg (HI + standard EN + Arg in equimolar concentration to Arg in IED), and HI-IED (HI + IED). These isocaloric and isonitrogenous diets were administered over 4 days. After death, the thymus was removed and weighed. The density of CD25, CD4 and CD8 on lymphocytes from blood and from Peyer patches was evaluated. Mesenteric lymph nodes, liver and spleen were cultured for analysis of enterobacterial translocation and dissemination.

MEASUREMENTS AND RESULTS

HI induced an atrophy of the thymus which was not corrected by the standard diet (HI 0.27 +/- 0.03, HI-STD 0.35 +/- 0.03 vs. AL 0.49 +/- 0.02 g; p < 0.05). However, the standard diet supplemented with arginine limited the thymic atrophy and the IED restored thymus weight. CD25 density and interleukin-2 production were increased only in the HI-STD-Arg and HI-IED groups (p < 0.05). Head injury induced enterobacterial translocation and dissemination which were blunted only in the HI-STD-Arg group (p < 0.05).

CONCLUSIONS

In this rat HI model, arginine appears to be safe, contributes to a large extent to the immunomodulatory effects of the IED, and seems to limit enterobacterial translocation and dissemination more efficiently alone than in an IED.

Metabolism and nutrition in patients with moderate and severe traumatic brain injury: A systematic review

PRIMARY OBJECTIVE

To examine the evidence on the metabolic state and nutritional treatment of patients with moderate-to-severe traumatic brain injury (TBI).

RESEARCH DESIGN

A systematic review of the literature.

METHODS AND PROCEDURES

From 1547 citations, 232 articles were identified and retrieved for text screening. Thirty-six studies fulfilled the criteria and 30 were accepted for data extraction.

MAIN OUTCOMES AND RESULTS

Variations in measurement methods and definitions of metabolic abnormalities hampered comparison of studies. However, consistent data demonstrated increased metabolic rate (96-160% of the predicted values), of hypercatabolism (-3 to -16 g N per day) and of upper gastrointestinal intolerance in the majority of the patients during the first 2 weeks after injury. Data also indicated a tendency towards less morbidity and mortality in early fed patients.

CONCLUSIONS

The impact of timing, content and ways of administration of nutritional support on neurological outcome after TBI remains to be demonstrated.

Energy expenditure in hospitalized patients: implications for nutritional support

An understanding of energy expenditure in hospitalized patients is necessary to determine optimal energy supply in the care of individuals who require nutritional support. A review was conducted of 19 studies in which resting energy expenditure (REE) had been measured using indirect calorimetry and compared with estimated basal energy expenditure (BEE) from the Harris-Benedict equation. Studies of patients with burns, head injuries, and fever were excluded because REE is known to be increased in these conditions. The studies reported data on 1256 patients with the following diagnoses: postoperative (28%), trauma or sepsis (26%), cancer (18%), pulmonary disease (9%), cardiovascular disease (2%), miscellaneous (9%), and unspecified (6%). The average REE in the 19 studies was 113% of the BEE. The mean +/- SD REE/BEE ratio was higher in 11 studies in which the REE was measured during feeding than in 5 studies in which the measurement was made during fasting (117% +/- 3% vs 105% +/- 4%; P = .047). In those 11 studies, overfeeding may have contributed to higher REE values than otherwise would have been observed. Some evidence indicated that the REE/BEE ratio is higher in more severe illness, but results were inconsistent. Unfortunately, little information is available concerning total energy expenditure, which includes the contribution of physical activity. It appears that most patients can be fed adequately with energy equal to 100% to 120% of estimated BEE. Hypoenergetic feeding may be appropriate in some overweight and obese individuals. Additional research in hospitalized patients on total energy expenditure and on the relationship between severity of illness and energy expenditure is needed.

Prevalence and Characteristics of Adverse Drug Reactions in Neurosurgical Intensive Care Patients

OBJECTIVE:

To evaluate the prevalence and characteristics of adverse drug reactions (ADRs) in neurosurgical intensive care patients.

METHODS:

Retrospective analysis of ADR data obtained from a spontaneous reporting system in a tertiary care university hospital. Reports of suspected ADRs in adult patients admitted emergently or electively to the neurosurgical service were included.

RESULTS:

Over the 3 year period, 3496 neurosurgical intensive care unit (ICU) patient admissions accounted for 5% of all hospital admissions. A total of 10% of all neurosurgical patients developed a suspected ADR, with three patients experiencing multiple reactions. Other adult ICU patients developed ADRs at a comparable rate (9%, P&gt;0.05). Overall, neurosurgery patients accounted for 12% of all spontaneously reported ADRs. Preventable reactions were observed in 43 (13%) cases, and treatment was required for 76%. The majority (96%) of ADRs resolved or improved at the time of the ADR report. Nausea, pruritus, thrombocytopenia, and vomiting were most frequently noted. Therapies most often associated with reported events were analgesics, antipyretics, antibiotics, anticonvulsants, and histamine H2 antagonists. The relationship between central nervous system disease and adverse event occurrence is not clear.

CONCLUSION:

Despite the narrow scope of drug regimens in neurosurgical ICU patients, ADRs can complicate therapy in this critically ill population. Neurosurgical ICU patients seem to experience ADRs no more frequently than their adult ICU counterparts.

Percutaneous endoscopic gastrostomy: a safe and effective bridge for enteral nutrition in neurological or non-neurological conditions

Percutaneous endoscopic gastrostomy (PEG) is one of the most commonly used methods for nutritional support in patients who are unable to take food orally. Traditional surgical gastrostomy, percutaneous radiologic gastrostomy, and laparoscopic gastrostomy are the alternatives. The most common indication is neurogenic dysphagia followed by obstructive causes such as head and neck tumors. Ethically justified and clinically comprehensive guidelines should be followed during the decision-making process for PEG tube placement. A limited life expectancy; technical difficulties, such as the inability to bring the anterior gastric wall in apposition to the abdominal wall; or pharyngeal/esophageal obstruction, which compromise tube insertion, peritonitis, and uncorrectable coagulopathy are absolute contraindications. The "pull method" is the first described and still the most performed technique of PEG tube placement. The procedure is simple, safe, and effective and fulfills all requirements to provide an ideal route for nutritional support. This article summarizes the reported experience on PEG in the current literature and discusses its utility in patients with neurological conditions.

Secondary hypoxia exacerbates acute disruptions of energy metabolism in rats resulting from fluid percussion injury

The purpose of these experiments was to determine whether secondary hypoxia exacerbates the metabolic consequences of fluid percussion injury (FPI). In Experiment I, rats were trained to press a lever for their entire daily ration of food at any time during a 12-h light/dark cycle and run in an activity wheel. After food intake and body weight stabilized, rats were surgically prepared, assigned to one of four groups [FPI+Hypoxia (IH), FPI+Normoxia (IN), Sham Injury+Hypoxia (SH), Sham Injury+Normoxia (SN)] and, after recovery from surgery, anesthetized with halothane delivered by a 21% O2 source. Immediately after injury or sham injury, the O2 source was switched to 13% for rats in Groups IH and SH for 30 min. Post-traumatic hypoxemia exacerbated the ensuing FPI-induced reductions of food intake and body weight, but did not change FPI-induced reduction in wheel running. In Experiment II, rats were assigned to one of three groups (SH, IN, or IH) and subjected to sham injury and 13% O2 or FPI and either 13 or 21% O2. Immediately after 30 min of hypoxia or normoxia, rats were confined to metabolism cages that were used to quantify rates of oxygen consumption (VO2), carbon dioxide production (VCO2), and heat production (H). Post-traumatic hypoxia exacerbated the FPI-induced increases in VO2, VCO2, and H. The results of Experiments I and II provide convergent confirmation that secondary hypoxemia exacerbates the FPI-induced hypermetabolic state in rats and therefore might significantly exacerbate the brain injury-induced disruptions of energy metabolism in humans.

The Brain Trauma Foundation. The American Association of Neurological Surgeons. The Joint Section on Neurotrauma and Critical Care. Nutrition

Data show that starved head-injured patients lose sufficient nitrogen to reduce weight by 15% per week. Class II data show that 100-140% replacement of resting metabolism expenditure with 15-20% nitrogen calories reduces nitrogen loss. Data in non-head injured patients show that a 30% weight loss increased mortality rate. Class I data suggests that nonfeeding of head-injured patients by the first week increases mortality rate. The data strongly support feeding at least by the end of the first week. It has not been established that any method of feeding is better than another or that early feeding prior to 7 days improves outcome. Based on the level of nitrogen wasting documented in head-injured patients and the nitrogen sparing effect of feeding, it is a guideline that full nutritional replacement be instituted by day 7.

Energy expenditure in disease: time to revisit?

Knowledge of energy expenditure is especially important in disease, and may in fact help in the understanding of the pathophysiology of wasting associated with disease. Energy requirements in a clinical setting are often 'prescribed' by health professionals, either directly through enteral or parenteral feeding, or perhaps controlled through a hospital diet. Studies initially suggested an increase in energy expenditure, and thus energy requirements, as a direct result of an increase in basal metabolic rate often seen in disease. However, many problems exist in the measurement of BMR in a disease situation, due to the effects of drugs, clinical practice, feeding or possibly anxiety either as a cause of the disease or the measurement itself. These problems could in themselves contribute to the rise in metabolism seen in disease. More recently, however, with the use of tracer techniques such as doubly-labelled water and the bicarbonate-urea method, more accurate estimates of energy expenditure, and thus energy requirements, have been made. Some such measurements have in fact shown that even with an elevated BMR, free-living total energy expenditure can in fact be reduced in many disease situations, suggesting a reduced rather than an increased energy requirement. The present review investigates measurements of total energy expenditure in disease to explore the hypothesis that energy expenditure in disease, even with an elevated BMR, can in fact be reduced due to a concurrent reduction in physical activity.

Prospective, randomized, controlled trial to determine the effect of early enhanced enteral nutrition on clinical outcome in mechanically ventilated patients suffering head injury

OBJECTIVE

To determine the effect of early enhanced enteral nutrition (EN) on clinical outcome of head-injured patients.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Tertiary neurosurgical and trauma center.

PATIENTS

Eighty-two patients suffering head injury and requiring mechanical ventilation.

INTERVENTIONS

Patients were randomized to receive standard EN (gradually increased from 15 mL/hr up to estimated energy and nitrogen requirements) or enhanced EN (started at a feeding rate that met estimated energy and nitrogen requirements) from day 1. Good neurologic outcome (Glasgow Outcome Scale score of 4 or 5) was determined at 3 and 6 months after injury, and the incidence of infective and total complications was determined during the hospital stay up to 6 months.

MEASUREMENTS AND MAIN RESULTS

Disease severity assessed by best preintubation Glasgow Coma Scale score, pupillary responses, Injury Severity Score, Acute Physiology and Chronic Health Evaluation II score, computed tomographic scan categorization, and age was similar in both groups. Intervention patients had a higher percentage of energy (p = .0008) and nitrogen (p<.0001) requirements met by EN in the first week after injury. Neurologic outcome at 6 months was similar between groups, but there was a tendency for more intervention patients to have a good neurologic outcome at 3 months than control patients (61% vs. 39%, p = .08). Fewer intervention patients had an infective complication (61% vs. 85%, p = .02) or more than one total complication (37% vs. 61%, p = .046) compared with control patients. Enhanced EN was associated with a reduction in the ratio of serum concentration of C-reactive protein to albumin up to day 6 after injury (p = .004).

CONCLUSIONS

Enhanced EN appears to accelerate neurologic recovery and reduces both the incidence of major complications and postinjury inflammatory responses.

Acute intracranial hypertension-induced inhibition of gastric emptying: evaluation in conscious rats

To study the effect of raised intracranial pressure (ICP)-induced alterations in gastric emptying, and their modulation by pharmacological interventions, an experimental model was standardized in rats. A test meal of methylcellulose and phenol red was administered intragastrically. ICP was raised to 40, 60 and 80 mmHg by connecting a buffered saline pressure head to an intracerebroventricular (i.c.v.) cannula. Gastric emptying was estimated after killing the animals, from the residual stomach phenol red content. Inhibition of gastric emptying was observed when ICP was raised, the maximum being at 80 mmHg ICP (percent gastric emptying 26.5%+/-2.8 vs. 83.4+/-4.7 in sham-ICP). Pretreatment with clonidine, prazosin or ondansetron did not modify the raised ICP-induced inhibition of gastric emptying. Cisapride was ineffective at 1 mg/kg but caused a partial reversal at the 5- and 10-mg/kg doses (46.9+/-3.1% and 42.6+/-4.0%, respectively). Carbachol at a lower dose of 0.1 mg/kg i.p., produced a greater reversal (78.3+/-6.0%) than did the high dose (52.8+/-4.1). Bretylium partially reversed the inhibition of gastric emptying (45.7+/-4.3%). The protective effect of carbachol and cisapride suggests that suppression of vagal activity due to increased ICP may play an important role in the inhibition of gastric emptying due to intracranial hyper-tension.

[Is the metabolic response self-limited in head trauma? Analysis of acute phase proteins and glycemia]

There are many reports supporting a self-limitation mechanism involved with hypermetabolic response after severe cranial injury. It was proposed a study with severe head injury patients, in three stages of the evolution. The first 7 days after admission (moment 1-M1), the second three days latter (M2) and the last 7 days after the first (M3). Among male patients with severe head injury, attended between January 1992 and December 1993 in University Hospital of Botucatu, UNESP, were selected 28 male patients, with Glasgow severity scale between 4 and 6, with pO2 < 70 mm Hg, weighting 60 kg or more. Among these patients, 6 finished the study, including analysis of the excretion of N, acute phase proteins, glycemia, triglycerides and amine nitrogen. During the study there were no changes in nitrogen balance and there was a decrease in protein C-reative. Glycemia tends to fall within two weeks after injury. The authors make some considerations about possible mechanisms involved in brain modulation associated with the period of dependence of hypermetabolism and hypercatabolism after closed brain injury. There are some evidences that the brain responds to head trauma with a gobal non specific way, which tends to be reorganized beyond the first two weeks after lesion. The study does not show any influence of the type and severity of head trauma.

Decreased soluble adhesion molecule L-selectin plasma concentrations after major trauma

BACKGROUND

Binding of the leukocyte glycoprotein L-selectin to ligands expressed by activated endothelium directs leukocyte recruitment to areas of acute inflammation. Sequestration by activated microvascular endothelium has been proposed to explain the low plasma concentrations of soluble L-selectin (sCD62L) observed early in patients with acute respiratory distress syndrome. We hypothesized that inflammatory endothelial activation may occur in trauma patients, leading to decreased sCD62L plasma concentrations.

METHODS

This study was a prospective analysis of sCD62L plasma concentrations in patients with isolated head injuries and multiple trauma patients without head injuries admitted to two tertiary-level intensive care units. sCD62L plasma concentrations were determined in 18 consecutive adult patients with isolated moderate and severe head injuries and in 13 multiple trauma patients without head injuries immediately upon admission to the intensive care unit and then daily for up to 10 days after trauma.

RESULTS

Compared with healthy adult controls (n=22), patient sCD62L plasma concentrations were significantly decreased upon admission (5.7+/-1.6 vs. 11.0+/-1.7 pmol/mL; p < 0.001). In all patients, sCD62L concentrations remained depressed throughout the study period. sCD62L concentrations did not differ significantly between patients with isolated head injuries and multiple trauma patients without head injuries, although repeated-measures analysis of variance showed significantly more depressed sCD62L concentrations associated with severe (n=14) compared with moderate head injuries (n=4) during the study period (p < 0.05).

CONCLUSION

Patients with major trauma present with a significant reduction of sCD62L plasma concentrations within the first 12 hours after trauma and during subsequent intensive care. This finding suggests widespread microvascular endothelial activation after trauma, which may be associated with increased neutrophil extravasation.

Metabolic profiles of patients with subarachnoid hemorrhage treated by early surgery

OBJECTIVE

This study was conducted to evaluate the metabolic response of patients with subarachnoid hemorrhage (SAH) and to determine whether the severity of hemorrhage influenced the response.

METHODS

Resting energy expenditure, nitrogen balance, and serum rapid-turnover proteins were studied for 3-day periods at Day 4, Day 10, and before discharge in patients with SAH who underwent surgical clipping within 2 days after the onset. The patients were divided into two groups according to the Hunt and Hess classification system; there were 17 patients with Grade I or II (mild group) and 19 patients with Grade III, IV, or V (severe group).

RESULTS

The mean resting energy expenditures (mean+/-standard deviation) were highest on Day 10, which were 146+/-24% and 198+/-78% of basal energy expenditure in the mild and severe groups, respectively. The nitrogen balance levels of the mild group on Days 4 and 10 were -3.0+/-3.5 g per day and -4.5+/-2.9 g per day, and those of the severe group were -7.5+/-3.2 g per day and -9.2+/-4.1 g per day, respectively. There was a significant difference in the nitrogen balance over time between the two groups (P=0.0037). Serum transferrin, prealbumin, and retinol-binding protein levels were lowest on Day 4 and gradually increased. There were no significant differences in these parameters between the two groups.

CONCLUSION

SAH treated by surgery induces a profound stress response. A significant difference of increased catabolism but not decreased anabolism between the mild and severe groups was noted.

Intravenous insulin-like growth factor-I (IGF-I) in moderate-to-severe head injury: a phase II safety and efficacy trial

The purpose of this study was to determine the effect of insulin-like growth factor-I (IGF-I) on the catabolic state and clinical outcome of head-injured patients. Thirty-three patients between the ages of 18 and 59 years with isolated traumatic head injury and Glasgow Coma Scale (GCS) scores of 4 to 10 were randomized to one of two groups. All patients received standard neurosurgical intensive care plus aggressive nutritional support; the patients in the treatment group also received intravenous therapy with continuous IGF-I (0.01 mg/kg/hour). During the 14-day dosing period, the control patients lost weight, whereas treated patients gained weight despite a significantly higher measured energy expenditure and lower caloric intake (p = 0.02). Daily glucose concentrations and nitrogen outputs were greater in control patients (p = 0.03) throughout the study period. During Week 1, only treated patients achieved positive nitrogen balance. Fifteen of 17 treated and 13 of 16 control patients survived the 1st week. No deaths occurred in patients whose serum IGF-I concentrations were higher than 350 ng/ml. Dichotomized Glasgow Outcome Scale scores for patients with baseline GCS scores of 5 to 7 improved from poor to good for eight of 12 treated patients but for only three of 11 control patients (p = 0.06). Eight of 11 treated patients with serum IGF-I concentrations that were at least 350 ng/ml achieved moderate-to-good outcome scores at 6 months, compared to only one of five patients with lower concentrations (p < 0.05). These findings indicate that pharmacological concentrations of IGF-I may improve clinical outcome and nitrogen utilization in patients with moderate-to-severe head injury.

Effect of acute phase response on phenytoin metabolism in neurotrauma patients

The purpose of this prospective study was to correlate measures of the acute phase response, associated therapeutic interventions, and other clinical variables with the process of altered drug metabolism previously observed in patients with severe neurotrauma. Nine patients with severe head injury (Glasgow Coma Scale < or = 8) requiring intravenous phenytoin were included in the study. A loading dose of phenytoin was followed by daily maintenance doses. Serial blood samples were taken after the loading dose and every even-numbered study day for 10 to 14 days for measurement of total and unbound concentrations of phenytoin, interleukin-1 beta, interleukin-6 (IL-6), tumor necrosis factor alpha, alpha 1-acid-glycoprotein, C-reactive protein, and albumin. Time-invariant and time-variant Michaelis-Menten models were fit to the phenytoin concentration-time data. Protein intake was closely monitored. The mean (+/- SEM) unbound fraction of phenytoin increased from 0.17 +/- 0.02 on day 1 to 0.24 +/- 0.04 on day 10 (P < 0.05). The time-variant model was superior in describing the concentration-time data of unbound phenytoin in eight of nine patients. Mean (+/- SEM) pharmacokinetic parameter estimates for unbound phenytoin were: Vmax delta = 605 +/- 92 mg/day, VmaxB = 149 +/- 26.3 mg/day, K(ind) = 0.013 +/- 0.004 hr-1. Interleukin-6 was the only cytokine with significant concentration changes over time; it was inversely correlated with Vmax,t. Peak concentrations of interleukin-6 also proved to be inversely correlated with VmaxB. The daily amount of protein administered was significantly correlated with Vmax,t. Significant alterations in the metabolism of phenytoin occur after severe neurotrauma. The etiology of these changes is probably multifaceted. These results suggest that low initial phenytoin Vmax may be explained by the presence of interleukin-6. An increase in oxidative metabolism that correlated with nutritional protein administration was observed later in these patients.

Nutritional management of the critically ill neurologic patient

To summarize, the event of severe neurologic injury results in significant metabolic changes. These changes cause increased requirements for protein and nonprotein calories, micronutrients, and small bowel feedings or TPN. Early feeding has been shown to improve survival. Therefore, every effort should be made to provide aggressive nutritional support within the first 72 hours after injury. Specific guidelines are as follows: Provide full-strength, full-rate feedings within 72 hours. Provide enteral nutrients via nasojejunal or percutaneous endoscopic jejunostomy feeding tube if access is available; attempt gastric feedings if not. Provide TPN within 48 hours if enteral access is not available and begin enteral feeding as soon as possible. Provide 2 to 2.3 g protein/kg/d if renal function is normal. Provide 40% to 70% above basal needs as total calories, with 30% to 40% of calories as lipid to minimize hyperglycemia. Provide protein as small peptides to improve tolerance, absorption, utilization, and gut integrity. Provide a lipid source with 50% to 70% medium-chain triglycerides and an omega-6 to omega-3 ratio of 2:1 to 8:1 to minimize negative effects of omega-6 fatty acids and provide an easily absorbed and utilized source of lipid.

Alteration of carbamazepine pharmacokinetics in patients with traumatic brain injury

All patients admitted to a rehabilitation unit with closed-head injury over a 3-year period were reviewed for carbamazepine use exceeding 30 days in the hospital. Nine patients met the study inclusion criteria for age and duration of carbamazepine therapy. On review of the dose:serum concentration relationship, significant changes were noted in four patients. An initial increase in the dose:serum concentration ratio during the first few months of therapy was thought to reflect the well-known auto-induction of carbamazepine metabolism. However, unexplainable decreases in the dose:serum concentration occurred in the following months, and suggested alteration of carbamazepine pharmacokinetics in patients with traumatic brain injury. The finding may be important in determining the optimal approach to therapeutic drug monitoring of carbamazepine in brain-injured patients.

Metabolic rate in severe head trauma

BACKGROUND

The metabolic rate of patients suffering severe head trauma (HT) is not well defined, and large variations of resting energy expenditure (REE) have been reported, suggesting an important nonuniformity of REE distribution in HT patients. The purpose of this clinical study was to assess the metabolic rate in mechanically ventilated patients suffering from severe isolated HT, or HT associated with other injuries, in the absence of gross motor activity.

METHODS

Eighty HT patients undergoing mechanical ventilation were studied between 48 and 72 hours after injury. Three groups of patients were studied in the following clinical settings: (group A) isolated HT, not receiving morphine (n = 34); (group B) isolated HT, receiving an intravenous perfusion of morphine (n = 26) to control gross motor activity; and (group C) HT associated with other serious injuries, receiving intravenous morphine (n = 20) to induce sedation and analgesia. REE was measured with the open-Douglas-bag method.

RESULTS

No significant differences among the three groups were found in the metabolic rate expressed as the percentage of measured REE from predicted REE and REE expressed in terms of body weight. The mean percent measured REE was 123 +/- 16, and REE expressed in terms of body weight was 30 +/- 5 kcal/kg per day. Severe hypermetabolism was diagnosed if mean percent measured REE was greater than 130 and was present in 25 of 80 (31%) patients.

CONCLUSIONS

Severe HT treated with or without morphine was characterized by a moderate state of hypermetabolism after the first days of trauma, but an important proportion of HT patients showed considerably elevated metabolic rates.