Physiological and metabolic response to isolated closed-head injury. Part 1: Basal metabolic state: correlations of metabolic and physiological parameters with fasting and stressed controls

Malnutrition Essentials for Neurologists and Neurosurgeons: A Review of the Literature

Malnutrition still causes deaths in the world today and protein energy malnutrition (PEM) is characterized by increased oxidative stress, immune deficiency, and development of various infections. Even today, however, it is an underrecognized and undertreated entity in neurology and neurosurgery. In this article, we therefore seek to review the available literature regarding various factors affecting surgical outcome of children with malnutrition undergoing some neurosurgical interventions including shunt surgery and traumatic brain injury in intensive care unit, in addition to its effects upon oxidative stress status and immunity. Furthermore, we attempt to provide essential knowledge of malnutrition affecting surgical outcome of patients with PEM. Based on available evidence in the published literature, it is concluded that it is a serious public health problem characterized by increased oxidative stress, immune deficiency, and development of various infections.

Controversies of enteral nutrition in select critically-ill surgical patients: Traumatic brain injury, extracorporeal life support, and sepsis

Adequate nutritional support for critically ill pediatric patients is an essential component of optimal care in the intensive care unit. For select patient populations in this setting, the enteral delivery of nutrients can bring unique challenges and potential risks. The focus of this paper is to provide a review of existing literature concerning the safety, efficacy and benefits of enteral nutrition in select surgical patient populations for whom these discussions are most controversial: patients with traumatic brain injury, patients receiving extracorporeal life support (ECLS), and patients receiving vasopressor therapy, such as in sepsis. Recommendations in the context of consensus or a call to investigate research gaps are provided based on a review of the evidence.

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.

Early feeds not force feeds: Enteral nutrition in traumatic brain injury

BACKGROUND

Brain Trauma Foundation guidelines recommend the early use of enteral nutrition to optimize recovery following traumatic brain injury (TBI). Our aim was to examine the effect of early feeds (≤24 hours) on clinical outcomes after TBI.

METHODS

We performed a 3-year retrospective study of patients with severe TBI (Glasgow Coma Scale score <8) who were intubated, admitted to the intensive care unit (ICU), and received tube feeds. Early tube feeds (early TF) were defined as initiation of tube feeds within 24 hours, whereas late tube feeds (late TF) were defined as initiation of tube feeds after 24 hours. Outcome measures included pneumonia rates, days on ventilator, hospital and ICU stay, and mortality rates.

RESULTS

A total of 90 patients (early TF: 58, late TF: 32) were included, of which 73.3% were male, mean age was 42 (SD, 20) years, and median head Abbreviated Injury Scale score was 4 (range, 3-5). There was no difference in age (p = 0.1), head Abbreviated Injury Scale score (p = 0.5), or admission Glasgow Coma Scale score (p = 0.9) between the two groups. Patients with early TF were associated with higher number of ICU days (p = 0.03) and higher pneumonia rates (p = 0.04), but there was no significant difference in mortality (p = 0.44) as compared with those who underwent late TF.

CONCLUSIONS

Although early tube feeds are known to improve outcomes in TBI patients, our data suggest that early feeds in TBI patients are associated with higher rates of pneumonia and greater hospital resource utilization.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Updates in the management of the small animal patient with neurologic trauma

Neurologic trauma, encompassing traumatic brain injury (TBI) and acute spinal cord injury (SCI), is a cause of significant morbidity and mortality in veterinary patients. Acute SCIs occurring secondary to trauma are also common. Essential to the management of TBI and SCI is a thorough understanding of the pathophysiology of the primary and secondary injury that occurs following trauma. This article reviews the pathophysiology of this primary and secondary injury, as well as recommendations regarding clinical assessment, diagnostics, pharmacologic and nonpharmacologic therapy, and prognosis.

Disease-specific nutrition therapy: one size does not fit all

INTRODUCTION

The delivery of adequate nutrition is an integral part of the care of the critically ill surgical patient, and the provision of nutrition may have a greater impact on outcome than many other therapies commonly employed in the treatment of certain disease states.

METHODS

A review of the existing literature was performed to summarize the evidence for utilizing disease-specific nutrition in critically ill surgical patients.

RESULTS

Enteral nutrition, unless specifically contraindicated, is always preferable to parenteral nutrition. Methodological heterogeneity and conflicting results plague research in immunonutrition, and routine use is not currently recommended in critically ill patients.

CONCLUSION

There is currently insufficient evidence to recommend the routine initial use of most disease-specific formulas, as most patients with the disease in question will tolerate standard enteral formulas. However, the clinician should closely monitor for signs of intolerance and utilize disease-specific formulas when appropriate.

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.

Current and evolving management of traumatic brain injury

This article discuss the pathophysiology of traumatic brain injury and increased intracranial pressure, the consequences and treatment of secondary insults, and strategies for the medical and nursing management of the patient who has traumatic brain injury.

Parenteral and enteral nutrition in the management of neurosurgical patients in the intensive care unit

The iatrogenic malnutrition of neurosurgical patients in intensive care units (ICU) is an underestimated problem. It may cause a decrease in plasma albumin and oncotic pressure, leading to an increase in the amount of water entering the brain and increased intracranial pressure (ICP). This study was conducted to test the hypothesis that combined high-protein parenteral and enteral nutrition is beneficial for neurosurgical patients in ICU. A total of 202 neurosurgical patients in ICU (mean age+/-standard deviation, 56 years+/-16 years; male:female=1.2:1) were studied. Two consecutive 1-year time periods were compared, during which two different nutritional regimens were followed. In the first time period (Y1) patients were given a low-protein/high-fat formulation parenterally, followed by a standard enteral regimen. In the second time period (Y2) a protein-rich, combined parenteral and enteral diet was prospectively administered. The Glasgow Outcome Score was measured at 3-6 months after discharge. The following clinical parameters were recorded during the first 2 weeks after admission: ICP; albumin; cholinesterase (CHE); daily hours of ICP > 20 mmHg and cerebral perfusion pressure<70 mmHg; and Acute Physiology and Chronic Health Evaluation II (APACHE II) score. It was found that overall albumin (32.4 g/L+/-4.1g/L vs. 27.5 g/L+/-3.6g/L) and CHE was higher during Y2, although the total energy supply, glucose and fat intake was lower. Higher GOS scores were seen when patients had lower APACHE II scores and received the Y2 nutritional regimen. During Y2, the total hours of ICP > 20 mmHg were fewer. With the Y2 nutrition, maintenance of adequate cerebral perfusion required less catecholamine medication and colloidal fluid replacement. Therefore, adequate nutrition is an important parameter in the management of neurosurgical patients in ICU.

Effect of early nutrition on deaths due to severe traumatic brain injury

Object

Traumatic brain injury (TBI) remains a serious public health crisis requiring continuous improvement in pre-hospital and inhospital care. This condition results in a hypermetabolic state that increases systemic and cerebral energy requirements, but achieving adequate nutrition to meet this demand has not been a priority in reducing death due to TBI. The effect of timing and quantity of nutrition on death within the first 2 weeks of injury was analyzed in a large prospective database of adult patients with severe TBI in New York State.

Methods

The study is based on 797 patients with severe TBI (Glasgow Coma Scale [GCS] score < 9) treated at 22 trauma centers enrolled in a New York State quality improvement program between 2000 and 2006. The inhospital section of the prospectively collected database includes information on age, initial GCS score, weight and height, results of CT scanning, and daily parameters such as pupillary status, arterial hypotension, GCS score, and number of calories fed per day.

Results

Patients who were not fed within 5 and 7 days after TBI had a 2- and 4-fold increased likelihood of death, respectively. The amount of nutrition in the first 5 days was related to death; every 10-kcal/kg decrease in caloric intake was associated with a 30–40% increase in mortality rates. This held up even after controlling for factors known to affect mortality, including arterial hypotension, age, pupillary status, initial GCS score, and CT scan findings.

Conclusions

Nutrition is a significant predictor of death due to TBI. Together with prevention of arterial hypotension, hypoxia, and intracranial hypertension it is one of the few therapeutic interventions that can directly affect TBI outcome.

The fate of glucose during the period of decreased metabolism after fluid percussion injury: a 13C NMR study

The present study determined the metabolic fate of [1, 2 13C2] glucose in male control rats and in rats with moderate lateral fluid percussion injured (FPI) at 3.5 h and 24 h post-surgery. After a 3-h infusion, the amount of 13C-labeled glucose increased bilaterally (26% in left/injured cerebral cortex and 45% in right cerebral cortex) at 3.5 h after FPI and in injured cortex (45%) at 24 h after injury, indicating an accumulation of unmetabolised glucose not seen in controls. No evidence of an increase in anaerobic glycolysis above control levels was found after FPI, as 13C-labeled lactate tended to decrease at both time points and was significantly reduced (33%) in the injured cortex at 24 h post-FPI. A bilateral decrease in the 13C-labeling of both glutamate and glutamine was observed in the FPI rats at 3.5 h and the glutamine pool remained significantly decreased in the injured cortex at 24 h, suggesting reduced oxidative metabolism in both neuronal and astrocyte compartments after injury. The percentage of glucose metabolism through the pentose phosphate pathway (PPP) increased in the injured (13%) and contralateral (11%) cortex at 3.5 h post-FPI and in the injured cortex (9%) at 24 h post-injury. Based upon the changes in metabolite pools, our results show an injury-induced decrease in glucose utilization and oxidation within the first 24 h after FPI. Increased metabolism through the PPP would result in increased NADPH synthesis, suggesting a need for reducing equivalents after FPI to help restore the intracellular redox state and/or in response to free radical stress.

Nutritional support for head-injured patients

BACKGROUND

Head injury increases the body's metabolic responses, and therefore nutritional demands. Provision of an adequate supply of nutrients is associated with improved outcome. The best route for administering nutrition (parenterally (TPN) or enterally (EN)), and the best timing of administration (for example, early versus late) of nutrients needs to be established.

OBJECTIVES

To quantify the effect on mortality and morbidity of alternative strategies of providing nutritional support following head injury.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Injuries Group specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, National Research Register, Web of Science and other electronic trials registers. Reference lists of trials and review articles were checked. The searches were last updated in July 2006.

SELECTION CRITERIA

Randomised controlled trials of timing or route of nutritional support following acute traumatic brain injury.

DATA COLLECTION AND ANALYSIS

Two authors independently abstracted data and assessed trial quality. Information was collected on death, disability, and incidence of infection. If trial quality was unclear, or if there were missing outcome data, trialists were contacted in an attempt to get further information.

MAIN RESULTS

A total of 11 trials were included. Seven trials addressed the timing of support (early versus delayed), data on mortality were obtained for all seven trials (284 participants). The relative risk (RR) for death with early nutritional support was 0.67 (95% CI 0.41 to 1.07). Data on disability were available for three trials. The RR for death or disability at the end of follow-up was 0.75 (95% CI 0.50 to 1.11). Seven trials compared parenteral versus enteral nutrition. Because early support often involves parenteral nutrition, three of the trials are also included in the previous analyses. Five trials (207 participants) reported mortality. The RR for mortality at the end of follow-up period was 0.66 (0.41 to 1.07). Two trials provided data on death and disability. The RR was 0.69 (95% Cl 0.40 to 1.19). One trial compared gastric versus jejunal enteral nutrition, there were no deaths and the RR was not estimable.

AUTHORS' CONCLUSIONS

This review suggests that early feeding may be associated with a trend towards better outcomes in terms of survival and disability. Further trials are required. These trials should report not only nutritional outcomes but also the effect on death and disability.

Survival, Hemodynamics, and Tissue Oxygenation after Head Trauma

BACKGROUND

The aims of this study were to describe the early time course of hemodynamic and tissue perfusion and oxygenation patterns in survivors and nonsurvivors after head injury; to suggest physiologic mechanisms responsible for the observed patterns; and to evaluate postinjury parameters that might be useful for treatment. The hypothesis was that reduced hemodynamics and tissue oxygenation and reduced arterial oxygen saturation affect outcomes.

STUDY DESIGN

Sixty patients with head trauma were noninvasively monitored on arrival in the emergency department to assess the temporal hemodynamic patterns associated with head injury; patients who were brain dead were excluded because they have very different hemodynamic patterns. Cardiac index, mean arterial pressure, and heart rate were monitored to assess cardiac function, pulse oximetry to reflect changes in pulmonary function, and transcutaneous oxygen and carbon dioxide to reflect tissue perfusion function. Patients were stratified by inhospital survival outcomes, the Glasgow Coma Scale, and the presence or absence of associated somatic injuries.

RESULTS

When all head injured patients were considered together, the predominant findings were high cardiac index, hypertension, mild tachycardia, normal pulmonary function, and reduced tissue oxygenation. The subset of survivors and those with high Glasgow Coma Scale had greater than normal cardiac index responses (4.02 +/- 0.01 (SEM) L/min/m2, p < 0.01 versus normal) and better tissue oxygenation (217 +/- 2 mmHg PtcO2/FiO2) than nonsurvivors (70 +/- 3 mmHg, p < 0.01) and those with low Glasgow Coma Scale (160 +/- 2, p < 0.05). Patterns of patients with associated somatic injuries were similar to those with isolated head injury.

CONCLUSIONS

The study suggested that survivors' cardiac index, tissue oxygenation, and arterial oxygen saturation may be considered as markers of resuscitation. Nonsurvivors of head injury had normal blood flow with reduced tissue oxygenation that might have contributed to unfavorable outcomes.

Nutritional support for head-injured patients

BACKGROUND

Head injury increases the body's metabolic responses, and therefore nutritional demands. Provision of an adequate supply of nutrients is associated with improved outcome. The best route for administering nutrition (parenterally (TPN) or enterally (EN)), and the best timing of administration (e.g early versus late) of nutrients needs to be established.

OBJECTIVES

To quantify the effect on mortality and morbidity of alternative strategies of providing nutritional support following head injury.

SEARCH STRATEGY

Trials were identified by computerised searches of the Injuries Group specialised register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and BIDS Index to Scientific and Technical Proceedings, and by checking the reference lists of trials and review articles.

SELECTION CRITERIA

Randomised controlled trials of timing or route of nutritional support following acute traumatic brain injury.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Information was collected on death, disability, and incidence of infection. If trial quality was unclear, or if there were missing outcome data, trialists were contacted in an attempt to get further information.

MAIN RESULTS

The timing of support: early versus delayed Of the seven trials addressing the timing of support, data on mortality were obtained for all seven trials (284 participants). The relative risk (RR) for death with early nutritional support was 0.67 (95% CI 0.41 to 1.07). Data on disability were available for three trials. The RR for death or disability at the end of follow-up was 0.75 (0.50 to 1.11). The route of feeding: parenteral versus enteral Seven trials compared parenteral versus enteral nutrition. Because early support often involves parenteral nutrition, three of the trials are also included in the previous analyses. Five trials (207 participants) reported mortality. The RR for mortality at the end of follow-up period was 0.66 (0.41 to 1.07). Two trials provided data on death and disability. The RR was 0.69 (95%Cl 0.40 to 1.19). 3. Enteral nutrition: jejunal versus gastric. There was one trial with no deaths and the RR is not estimable.

REVIEWER'S CONCLUSIONS

This review suggests that early feeding may be associated with a trend towards better outcomes in terms of survival and disability. Further trials are required. These trials should report not only nutritional outcomes but also the effect on death and disability.

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.

The metabolic response to acute traumatic brain injury and implications for nutritional support

An overview of the metabolic response to acute traumatic brain injury is presented. The consequences of hypermetabolism, hypercatabolism, and an altered immune function are discussed. Once a person with acute traumatic brain injury develops this hyperdynamic state, the resultant excessive protein breakdown ensues. This can lead to malnutrition. The feeding methods used to prevent malnutrition are discussed, along with the proper alimentation to provide to diminish the hyperdynamic state and improve immune function.

[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.

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.

Pentobarbital coma in neurosurgical patients: nutrition considerations

Neurosurgical patients in pentobarbital coma are a complex nutrition support population. Physiologic changes associated with the primary injury to the brain, combined with the pharmacodynamic influences of barbiturate therapy, contribute to the difficulties of initiating aggressive nutrition support. Early nutritional repletion is important to the overall outcome of traumatically injured patients. Consequently, factors that influence nutrition support decisions must be understood to assure appropriate intervention. The metabolic changes associated with traumatic head injury, pentobarbital therapy, and nutrition support strategies are reviewed.

Medical complications of head injury

There are many common and significant medical complications of head injury. These include (1) cardiovascular problems such as hyperdynamic state, myocardial injury, and dysrhythmias; (2) respiratory changes such as neurogenic pulmonary edema, hypoxia, abnormal ventilatory patterns, pulmonary infections, and pulmonary emboli secondary to deep vein thrombosis; (3) consumption coagulopathy; (4) water and electrolyte derangements--hypo- and hypernatremia; (5) hypothalamic/pituitary dysfunction--syndrome of inappropriate secretion of antidiuretic hormone and diabetes insipidus; (6) increased general metabolism with loss of immunocompetence, respiratory compromise, and complications of decreased activity; (7) gastrointestinal difficulties, particularly stress gastritis; and (8) infectious problems including those related to contamination from open wounds and foreign bodies such as monitors.

Quantification of midline shift as a predictor of poor outcome following head injury

A retrospective study of patient outcome, based on admission computed tomography, was carried out in 75 consecutive patients with head injury. Computed tomography data collected included the type and extent of intracranial hemorrhage, the extent of midline shift, and the ratio of midline shift compared with the extent of intracranial hemorrhage. Midline shift was considered to be out of proportion to intracranial hemorrhage when the midline shift of the septum pellucidum exceeded the extent of the hemorrhage as measured radially from the inner table of the skull. When computed tomography data were analyzed by logistic regression, significant predictive factors for poor outcome were intracranial hemorrhage (34%), intracranial hemorrhage with midline shift (61%), and midline shift out of proportion to the extent of intracranial hemorrhage (88%). When patient outcome and mortality rates are considered, our study indicates that midline shift out of proportion to the extent of intracranial hemorrhage is a highly useful predictor of poor patient outcome following head injury.

Traumatic brain injury creates biphasic systemic hemodynamic and organ blood flow responses in rats

Traumatic brain injury affects systemic circulation as well as directly damages the brain. The present study examined the effects of fluid percussion brain injury on systemic hemodynamics and organ arterial blood flow in rats. Rats were prepared for fluid percussion injury under anesthesia. Twenty-four hours later, rats were anesthetized (1.0% halothane in N2O:O2) and prepared for radioactive microsphere measurement of cardiac output and organ blood flow. After baseline blood flow and physiological measurements were established, the rats were injured (2.47 +/- 0.02 atm, n = 17) or not injured (n = 20). Additional blood flow determinations were made at two of the following four time (T) points: 5, 15, 30, and 60 min after the injury or sham injury. Fluid percussion brain injury produced an immediate systemic hypertension followed by a hypotension and low cardiac output. Organ blood flows remained constant or increased for 30 min and then declined. Decreased blood flow was most pronounced in the kidneys and the spleen and was less severe in the liver. The reduced cardiac output was redistributed to favor blood flow through the heart and pancreas. These data suggest that traumatic brain injury creates a hyperdynamic period followed by a hypodynamic state with a heterogeneous hypoperfusion among organs.

Elevated intracranial pressure associated with hypermetabolism in isolated head trauma

Both metabolic rate and protein catabolism are known to increase following severe head trauma, but the etiology of this hypermetabolism is unknown. To further investigate the problem, we studied the metabolism of 17 patients with indirect calorimetry who had severe craniocerebral trauma only and who required ICP monitoring for management. Patients were studied daily and immediately after ICP spikes greater than 20 mm Hg, prior to treatment with hyperventilation, osmotic diuretics, or barbiturates. Oxygen consumption (VO2) was correlated with ICP. Two groups of patients were identified. Group I patients were treated with hyperventilation and osmotic diuretics while Group II patients additionally received cerebral metabolic depressants. Group I had a significant correlation coefficient between VO2 and ICP. Significant hypercatabolism early in the post trauma period was demonstrated by increased urine urea nitrogen. Our observations suggest that in patients with craniocerebral trauma, elevated ICP is associated with increased oxygen consumption, protein catabolism and systemic hypermetabolism. Cerebral metabolic depressants blunted increases in VO2 which were seen with elevated ICP.

Post-traumatic personality: as many cases as individuals

Post traumatic personality do not present a unique picture because the disturbances have many causes. That is why models structured basically to the understanding of the disorders must be carried out.

Physiological and metabolic response to isolated closed-head injury. Part 2: Effects of steroids on metabolism. Potentiation of protein wasting and abnormalities of substrate utilization

In order to determine the effects of steroid administration on the metabolic response to isolated closed-head injury, a longitudinal study was performed. Metabolic indices were prospectively evaluated for the first 5 days postinjury in six patients who received steroids and 10 patients who did not. Patients were carefully screened to eliminate those with associated injuries as well as those with abnormalities due to sepsis. Other than steroid administration, a uniform treatment regimen was used in both groups. Metabolic indices measured on postinjury Days 1, 3, and 5 were analyzed. In addition, data were compared to results in large data banks obtained both from overnight-fasted patients (fasted controls) and from polytrauma victims (stressed controls). Both treatment groups were comparable with respect to age, mean Glasgow Coma Scale scores on admission and on Day 5, and initial intracranial pressure. Metabolic data indicated significantly higher levels of nitrogen excretion and somatic protein mobilization in steroid-treated patients than in patients not receiving steroids. In both groups, glucose levels, the lactate/pyruvate ratio, and branched-chain amino acid levels (all metabolic indices that correlate well with level of stress) initially corresponded to values for stressed controls. By Day 5, values for these variables were similar to fasted controls for the group not receiving steroids. In patients receiving steroids, however, the data remained similar to those for stressed controls. It is concluded that steroids prolong the metabolic abnormalities associated with the initial phase of head injury. In view of inconclusive data regarding benefit from steroid administration, serious questions must be raised regarding the use of these catabolic agents in this setting.