The metabolic response to severe head injury

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.

Computational modeling of targeted temperature management in post-cardiac arrest patients

Our core body temperature is held around [Formula: see text]C by an effective internal thermoregulatory system. However, various clinical scenarios have a more favorable outcome under external temperature regulation. Therapeutic hypothermia, for example, was found beneficial for the outcome of resuscitated cardiac arrest patients due to its protection against cerebral ischemia. Nonetheless, practice shows that outcomes of targeted temperature management vary considerably in dependence on individual tissue damage levels and differences in therapeutic strategies and protocols. Here, we address these differences in detail by means of computational modeling. We develop a multi-segment and multi-node thermoregulatory model that takes into account details related to specific post-cardiac arrest-related conditions, such as thermal imbalances due to sedation and anesthesia, increased metabolic rates induced by inflammatory processes, and various external cooling techniques. In our simulations, we track the evolution of the body temperature in patients subjected to post-resuscitation care, with particular emphasis on temperature regulation via an esophageal heat transfer device, on the examination of the alternative gastric cooling with ice slurry, and on how anesthesia and the level of inflammatory response influence thermal behavior. Our research provides a better understanding of the heat transfer processes and therapies used in post-cardiac arrest patients.

Protein requirements for critically ill ventilator-dependent patients with COVID-19

Background

Recent studies indicate critically ill patients with coronavirus disease 2019 (COVID‐19) are hypermetabolic; however, protein requirements in critically ill COVID‐19 patients are unknown. Our intent was to evaluate the nitrogen accretion response to varying protein intakes for critically ill ventilator‐dependent patients with COVID‐19.

Methods

Adult patients (age ≥ 18 years) with COVID‐19, admitted to the intensive care unit (ICU) and who required mechanical ventilation were retrospectively evaluated. Patients received continuous enteral nutrition (EN), including supplemental protein boluses, and had a 24‐h urine collection for determination of nitrogen balance (NBAL). Data are expressed as mean ± SD with a P‐value < .05 as significant.

Results

Twenty‐two patients provided 29 NBAL determinations. Protein intake from EN and protein supplements was 0.9 ± 0.7 g/kg/day at the time of the NBAL with an NBAL of –12.1 ± 10.9 g/day at 7 ± 4 days in the ICU. Combined caloric intake from EN and propofol at the time of the NBAL was 12 ± 8 kcal/kg/day. Nitrogen equilibrium (NBAL of –4 g/day or better) occurred in five patients. Patients achieving nitrogen equilibrium received more protein than those with a negative NBAL (1.2 ± 0.4 g/kg/day vs 0.8 ± 0.8 g/kg/day, P = .046). The linear regression for NBAL in response to graded increases in protein intake was as follows: NBAL = 8.5 × protein intake (g/kg/day) – 18.8 (r = 0.450, P < .001).

Conclusion

Critically ill ventilator‐dependent patients with COVID‐19 exhibit significant variability in nitrogen accretion response to increases in protein intake and often have a markedly negative NBAL.

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.

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.

Controlling nutritional status score and prognostic nutrition index predict the outcome after severe traumatic brain injury

OBJECTIVES

Immune-nutritional status is correlated with a clinical outcome in critical illness. Recently, controlling nutritional status (CONUT) score and prognostic nutrition index (PNI) has been reported to predict prognosis following cancer and other diseases. The aim of this study was to explore the relationship between the CONUT score and PNI and 6-month outcome in patients with severe traumatic brain injury (STBI).

METHODS

We retrospectively analyzed the clinical data of 78 patients with STBI, including the CONUT score and PNI. Patients were divided into high CONUT group and low CONUT group. Patients were also divided into high PNI and low PNI group respectively. The 6-month outcome was evaluated by the modified Rankin scale (mRS). The unfavorable outcome was defined as mRS score ≥3.

RESULTS

The unfavorable outcome group had lower Glasgow coma scale (GCS) scores, serum albumin, total cholesterol, PNI, and higher CONUT scores (P < 0.05). Both CONUT scores and PNI were strongly correlated with mRS (r = 0.429, P < 0.05; r = -0.590, P < 0.05, respectively). After adjustment for confounding factors, the odds ratios of CONUT scores and PNI for predicting unfavorable outcome were 10.478 (95% CI: 2.793-39.301) and -0.039 (95% CI: 0.008-0.204), respectively. The area under the curve (AUC) of CONUT scores for predicting unfavorable outcome was 0.777 (95% CI: 0.674-0.880, P < 0.01), which was similar to PNI (0.764, 95% CI: 0.657-0.87, P < 0.01).

CONCLUSION

Both CONUT scores and PNI might be novel independent predictors of the poor outcome in STBI.

Functional electrical stimulation-assisted cycle ergometry in the critically ill: protocol for a randomized controlled trial

BACKGROUND

Intensive care unit (ICU)-acquired weakness is the most important cause of failed functional outcome in survivors of critical care. Most damage occurs during the first week when patients are not cooperative enough with conventional rehabilitation. Functional electrical stimulation-assisted cycle ergometry (FES-CE) applied within 48 h of ICU admission may improve muscle function and long-term outcome.

METHODS

An assessor-blinded, pragmatic, single-centre randomized controlled trial will be performed. Adults (n = 150) mechanically ventilated for < 48 h from four ICUs who are estimated to need > 7 days of critical care will be randomized (1:1) to receive either standard of care or FES-CE-based intensified rehabilitation, which will continue until ICU discharge.

PRIMARY OUTCOME

quality of life measured by 36-Item Short Form Health Survey score at 6 months.

SECONDARY OUTCOMES

functional performance at ICU discharge, muscle mass (vastus ultrasound, N-balance) and function (Medical Research Council score, insulin sensitivity). In a subgroup (n = 30) we will assess insulin sensitivity and perform skeletal muscle biopsies to look at mitochondrial function, fibre typing and regulatory protein expression.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02864745. Registered on 12 August 2016.

Systematic review of factors associated with energy expenditure in the critically ill

BACKGROUND AND AIMS

Indirect calorimetry is the reference standard for energy expenditure measurement. Predictive formulae that replace it are inaccurate. Our aim was to review the patient and clinical factors associated with energy expenditure in critically ill patients.

METHODS

We conducted a systematic review of the literature. Eligible studies were those reporting an evaluation of factors and energy expenditure. Energy expenditure and factor associations with p-values were extracted from each study, and each factor was classified as either significantly, indeterminantly, or not associated with energy expenditure. Regression coefficients were summarized as measures of central tendency and spread. Metanalysis was performed on correlations.

RESULTS

The search strategy yielded 8521 unique articles, 307 underwent full text review, and 103 articles were included. Most studies were in adults. There were 95 factors with 352 evaluations. Minute volume, weight, age, % body surface area burn, sedation, post burn day, and caloric intake were significantly associated with energy expenditure. Heart rate, fraction of inspired oxygen, respiratory rate, respiratory disease diagnosis, positive end expiratory pressure, intensive care unit days, C- reactive protein, and size were not associated with energy expenditure. Multiple factors (n = 37) were identified with an unclear relationship with energy expenditure and require further evaluation.

CONCLUSIONS

An important interval step in the development of accurate formulae for energy expenditure estimation is a better understanding of relationships between patient and clinical factors and energy expenditure. The review highlights the limitations of currently available data, and identifies important factors that are not included in current prediction formulae of the critically ill.

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.

Enduring Neuroprotective Effect of Subacute Neural Stem Cell Transplantation After Penetrating TBI

Traumatic brain injury (TBI) is the largest cause of death and disability of persons under 45 years old, worldwide. Independent of the distribution, outcomes such as disability are associated with huge societal costs. The heterogeneity of TBI and its complicated biological response have helped clarify the limitations of current pharmacological approaches to TBI management. Five decades of effort have made some strides in reducing TBI mortality but little progress has been made to mitigate TBI-induced disability. Lessons learned from the failure of numerous randomized clinical trials and the inability to scale up results from single center clinical trials with neuroprotective agents led to the formation of organizations such as the Neurological Emergencies Treatment Trials (NETT) Network, and international collaborative comparative effectiveness research (CER) to re-orient TBI clinical research. With initiatives such as TRACK-TBI, generating rich and comprehensive human datasets with demographic, clinical, genomic, proteomic, imaging, and detailed outcome data across multiple time points has become the focus of the field in the United States (US). In addition, government institutions such as the US Department of Defense are investing in groups such as Operation Brain Trauma Therapy (OBTT), a multicenter, pre-clinical drug-screening consortium to address the barriers in translation. The consensus from such efforts including "The Lancet Neurology Commission" and current literature is that unmitigated cell death processes, incomplete debris clearance, aberrant neurotoxic immune, and glia cell response induce progressive tissue loss and spatiotemporal magnification of primary TBI. Our analysis suggests that the focus of neuroprotection research needs to shift from protecting dying and injured neurons at acute time points to modulating the aberrant glial response in sub-acute and chronic time points. One unexpected agent with neuroprotective properties that shows promise is transplantation of neural stem cells. In this review we present (i) a short survey of TBI epidemiology and summary of current care, (ii) findings of past neuroprotective clinical trials and possible reasons for failure based upon insights from human and preclinical TBI pathophysiology studies, including our group's inflammation-centered approach, (iii) the unmet need of TBI and unproven treatments and lastly, (iv) present evidence to support the rationale for sub-acute neural stem cell therapy to mediate enduring neuroprotection.

Muscle atrophy in mechanically-ventilated critically ill children

Importance

ICU-acquired muscle atrophy occurs commonly and worsens outcomes in adults. The incidence and severity of muscle atrophy in critically ill children are poorly characterized.

Objective

To determine incidence, severity and risk factors for muscle atrophy in critically ill children.

Design, setting and participants

A single-center, prospective cohort study of 34 children receiving invasive mechanical ventilation for ≥48 hours. Patients 1 week– 18 years old with respiratory failure and without preexisting neuromuscular disease or skeletal trauma were recruited from a tertiary Pediatric Intensive Care Unit (PICU) between June 2015 and May 2016. We used serial bedside ultrasound to assess thickness of the diaphragm, biceps brachii/brachialis, quadriceps femoris and tibialis anterior. Serial electrical impedance myography (EIM) was assessed in children >1 year old. Medical records were abstracted from an electronic database.

Exposures

Respiratory failure requiring endotracheal intubation for ≥48 hours.

Main outcome and measures

The primary outcome was percent change in muscle thickness. Secondary outcomes were changes in EIM-derived fat percentage and “quality”.

Results

Of 34 enrolled patients, 30 completed ≥2 ultrasound assessments with a median interval of 6 (IQR 6–7) days. Mean age was 5.42 years, with 12 infants <1 year (40%) and 18 children >1 year old (60%). In the entire cohort, diaphragm thickness decreased 11.1% (95%CI, -19.7% to -2.52%) between the first two assessments or 2.2%/day. Quadriceps thickness decreased 8.62% (95%CI, -15.7% to -1.54%) or 1.5%/day. Biceps (-1.71%; 95%CI, -8.15% to 4.73%) and tibialis (0.52%; 95%CI, -5.81% to 3.40%) thicknesses did not change. Among the entire cohort, 47% (14/30) experienced diaphragm atrophy (defined a priori as ≥10% decrease in thickness). Eighty three percent of patients (25/30) experienced atrophy in ≥1 muscle group, and 47% (14/30)—in ≥2 muscle groups. On multivariate linear regression, increasing age and traumatic brain injury (TBI) were associated with greater muscle loss. EIM revealed increased fat percentage and decreased muscle “quality”.

Conclusions and relevance

In children receiving invasive mechanical ventilation, diaphragm and other skeletal muscle atrophy is common and rapid. Increasing age and TBI may increase severity of limb muscle atrophy. Prospective studies are required to link muscle atrophy to functional outcomes in critically ill 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.

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.

Energy Expenditure in Patients With Nontraumatic Intracranial Hemorrhage

BACKGROUND

Patients with intracerebral (ICH), intraventricular (IVH) and subarachnoid hemorrhage (SAH) have increased morbidity and mortality compared with other forms of stroke. We postulate that the systemic inflammatory state triggered by these forms of nontraumatic intracranial hemorrhage (IH) translates into higher nutrition requirements than traditionally assumed. In order to test this hypothesis, we performed a retrospective study comparing the resting energy expenditure (REE) of 14 mechanically ventilated IH patients with the REE of 6 severe traumatic brain injury (sTBI) patients (a disease known to induce an increased metabolic state).

METHODS

Using nonparametric analysis, we compared 2 contemporary cohorts of patients-IH and sTBI-who required mechanical ventilation and who underwent indirect calorimetry (IC) within 7 days after the ictus.

RESULTS

Fourteen patients with nontraumatic IH (IVH, 2; SAH, 9; SAH/ICH, 1; ICH/SAH/IVH, 2) who underwent IC within 7 days from injury were identified; median age: 59 (28-84) years, median admission Glasgow Coma Scale (GCS): 6 (4-9), and median APACHE II: 19.5 (15-28). A control cohort of 6 patients with sTBI was identified; median age: 57.5 (18-80) years, admission GCS: 6.5 (4-8), and APACHE II: 16 (11-31). Sedation was used in 11/14 patients with IH and in 5/6 severe TBI patients. No patient was pharmacologically paralyzed. Median REE was 1810 (1124-2806) and 2238 (1860-2780) kcal/d for the IH and for the sTBI patient cohorts, respectively. Using Wilcoxon signed ranks test, the 2 patient groups were found comparable in regard to baseline clinical variables and disease severity (APACHE II). We did not identify a statistically significant difference in the REE between these 2 cohorts of patients (p = .25).

CONCLUSIONS

Patients with severe TBI and patients with IH have similar increments in metabolic rate during the initial phase (1 week from onset) of their disease. This information needs to be confirmed in a larger cohort of patients. If reproduced, our results suggest that nontraumatic IH patients are at high risk of inadequate nutrition if their metabolic rate is estimated after conventional nutrition practice.

Energy Expenditure and Protein Requirements After Traumatic Injury

Traumatic injury induces hypermetabolism. The degree of hypermetabolism can be variable, depending on the type of injury, the degree of inflammation, body composition, age, and treatment regimens. To estimate metabolic rate in some types of injury, predictive equations have been published. Some of these equations have been tested in validation studies. For other types of injury, equations do not exist. Some expert panels have recommended measuring in lieu of estimating metabolic rate, though studies have not been performed to determine whether clinical outcome is affected by the method used to determine energy requirements. Traumatically injured patients are usually catabolic, but protein needs after traumatic injury continue to be debated. Some suggest that 1.5 g protein per kg body weight is adequate and that any additional protein is simply oxidized, adding to the nitrogen load to be excreted. Alternately, protein intake >2.0 g/kg body weight increases the absolute rate of body protein synthesis, and achievement of nitrogen balance has been associated with survival. Thus, provision of high-protein feeding to achieve nitrogen balance might be worthwhile, even if that balance is achieved at the cost of additional nitrogen production.

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.

Enteral Nutrition for Patients With Traumatic Brain Injury in the Rehabilitation Setting: Associations With Patient Preinjury and Injury Characteristics and Outcomes

OBJECTIVE

To determine the association of enteral nutrition (EN) with patient preinjury and injury characteristics and outcomes for patients receiving inpatient rehabilitation after traumatic brain injury (TBI).

DESIGN

Prospective observational study.

SETTING

Nine rehabilitation centers.

PARTICIPANTS

Patients (N=1701) admitted for first full inpatient rehabilitation after TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

FIM at rehabilitation discharge, length of stay, weight loss, and various infections.

RESULTS

There were many significant differences in preinjury and injury characteristics between patients who received EN and patients who did not. After matching patients with a propensity score of >40% for the likely use of EN, patients receiving EN with either a standard or a high-protein formula (>20% of calories coming from protein) for >25% of their rehabilitation stay had higher FIM motor and cognitive scores at rehabilitation discharge and less weight loss than did patients with similar characteristics not receiving EN.

CONCLUSIONS

For patients receiving inpatient rehabilitation after TBI and matched on a propensity score of >40% for the likely use of EN, clinicians should strongly consider, when possible, EN for ≥25% of the rehabilitation stay and especially with a formula that contains at least 20% protein rather than a standard formula.

'Cool and quiet' therapy for malignant hyperthermia following severe traumatic brain injury: A preliminary clinical approach

Malignant hyperthermia increases mortality and disability in patients with brain trauma. A clinical treatment for malignant hyperthermia following severe traumatic brain injury, termed ‘cool and quiet’ therapy by the authors of the current study, was investigated. Between June 2003 and June 2013, 110 consecutive patients with malignant hyperthermia following severe traumatic brain injury were treated using mild hypothermia (35–36°C) associated with small doses of sedative and muscle relaxant. Physiological parameters and intracranial pressure were monitored, and the patients slowly rewarmed following the maintenance of mild hypothermia for 3–12 days. Consecutive patients who had undergone normothermia therapy were retrospectively analyzed as the control. In the mild hypothermia group, the recovery rate was 54.5%, the mortality rate was 22.7%, and the severe and mild disability rates were 11.8 and 10.9%, respectively. The mortality rate of the patients, particularly that of patients with a Glasgow Coma Scale (GCS) score of between 3 and 5 differed significantly between the hypothermia group and the normothermia group (P<0.05). The mortality of patients with a GCS score of between 6 and 8 was not significantly different between the two groups (P> 0.05). The therapy using mild hypothermia with a combination of sedative and muscle relaxant was beneficial in decreasing the mortality of patients with malignant hyperthermia following severe traumatic brain injury, particularly in patients with a GCS score within the range 3–5 on admission. The therapy was found to be safe, effective and convenient. However, rigorous clinical trials are required to provide evidence of the effectiveness of ‘cool and quiet’ therapy for hyperthermia.

Monitoring nutrition and glucose in acute brain injury

The metabolic response to injury is well described; however, very little is understood about optimal markers to measure this response. This summary will address the current evidence about monitoring nutritional status including blood glucose after acute brain injury (ABI). An electronic literature search was conducted for English language articles describing the testing, utility, and optimal methods to measure nutritional status and blood glucose levels in the neurocritical care population. A total of 45 articles were included in this review. Providing adequate and timely nutritional support can help improve outcome after ABI. However, the optimal content and total nutrition requirements remain unclear. In addition, how best to monitor the nutritional status in ABI is still being elucidated, and at present, there is no validated optimal method to monitor the global response to nutritional support on a day-to-day basis in ABI patients. Nitrogen balance may be monitored to assess the adequacy of caloric intake as it relates to protein energy metabolism, but indirect calorimetry, anthropometric measurement, or serum biomarker requires further validation. The adverse effects of hyperglycemia in ABI are well described, and data indicate that blood glucose should be carefully controlled in critically ill patients. However, the optimal frequency or duration for blood glucose monitoring after ABI remains poorly defined. There are significant knowledge gaps about monitoring nutritional status and response to nutritional interventions in ABI; these need to be addressed and hence few recommendations can be made. The optimal frequency and duration of blood glucose monitoring need further study.

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.

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.

A reappraisal of nitrogen requirements for patients with critical illness and trauma

BACKGROUND

Studies regarding protein requirements for patients with critical illness are inconclusive owing to small sample size and population heterogeneity. The primary objectives of this study were to determine the amount of protein required to achieve nitrogen equilibrium or a positive nitrogen balance (NB, -4 g/d or better) and ascertain whether patients with traumatic brain injury (TBI) exhibit greater protein catabolism than those without TBI.

METHODS

Adult patients admitted to the trauma center, given specialized nutrition support, and had an NB determination within 5 days to 14 days after injury were evaluated. Patients with obesity, incomplete urine collection, kidney disease, corticosteroid or pentobarbital therapy, or an oral diet were excluded.

RESULTS

A total of 300 NB determinations from 249 patients were evaluated. Increasing the protein dosage generally resulted in improved NB; however, the data were highly variable. Of the patients who received a protein intake of 2 g/kg per day or greater, 54% achieved nitrogen equilibrium or positive NB (-4 g/d or better) in contrast to 38% and 29% of patients who received 1.5 g/kg per day to 1.99 g/kg per day and 1 g/kg per day to 1.49 g/kg per day, respectively (p < 0.001). There was no significant difference in NB between patients with and without TBI at similar protein intakes.

CONCLUSION

A higher protein intake was generally associated with an improved NB; yet, many patients remained having a negative NB. A protein dosage of 2 g/kg per day or greater was more successful in achieving nitrogen equilibrium than were lower-dosage intakes. Patients with TBI do not exhibit significantly greater protein catabolism than do patients without TBI.

LEVEL OF EVIDENCE

Prognostic study, level III.

Adequacy of early enteral nutrition in adult patients in the intensive care unit

AIMS AND OBJECTIVES

To evaluate the adequacy of energy and protein intake of patients in a Korean intensive care unit in the first four days after initiation of enteral feeding and to investigate the factors that had impact on adequate intake.

BACKGROUND

Underfeeding is a common problem for patients hospitalised in the intensive care unit and is associated with severe negative consequences, including increased morbidity and mortality.

DESIGN

A prospective, cohort study was conducted in a medical intensive care unit of a university hospital in Korea.

METHODS

A total of 34 adult patients who had a primary medical diagnosis and who had received bolus enteral nutrition for the first four days after initiation of enteral nutrition were enrolled in this study. The data on prescription and intake of energy and protein, feeding method and feeding interruption were recorded during the first four days after enteral feeding initiation. Underfeeding was defined as the intake <90% of required energy and protein.

RESULTS

Most patients (62%) received insufficient energy, although some (29%) received adequate energy. More than half of patients (56%) had insufficient protein intake during the first four days after enteral feeding was initiated. Logistic regression analysis showed that the factors associated with underfeeding of energy were early initiation of enteral nutrition, under-prescription of energy and prolonged interruption of prescribed enteral nutrition.

CONCLUSION

Underfeeding is frequent in Korean critically ill patients owing to early initiation, under-prescription and prolonged interruption of enteral feeding.

RELEVANCE TO CLINICAL PRACTICE

  Interventions need to be developed and tested that address early initiation, under-prescription and prolonged interruption of enteral nutrition. Findings from this study are important as they form the foundation for the development of evidence-based care that is badly needed to eliminate underfeeding in this large vulnerable Korean intensive care unit population.

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.

Early enteral nutrition and clinical outcomes of severe traumatic brain injury patients in acute stage: a multi-center cohort study

Guidelines for patients with severe traumatic brain injury (sTBI) published in 2007 recommend providing early nutrition after trauma. Early enteral nutrition (EN) started within 48 h post-injury reduces clinical malnutrition, prevents bacterial translocation from the gastrointestinal tract, and improves outcome in sTBI patients sustaining hypermetabolism and hypercatabolism. The aim of this study was to examine the effect of early EN support on survival rate, Glasgow Coma Scale (GCS) score, and clinical outcome of sTBI patients. Medical records of sTBI patients with GCS scores 4-8 were recruited from 18 hospitals in Taiwan, excluding patients with GCS scores ≤3. During 2002-2010, data from 145 EN patients receiving appropriate calories and nutrients within 48 h post-trauma were collected and compared with 152 non-EN controls matched for gender, age, body weight, initial GCS score, and operative status. The EN patients had a greater survival rate and GCS score on the 7th day in the intensive care unit (ICU), and a better outcome at 1 month post-injury. After adjusting for age, gender, initial GCS score, and recruitment period, the non-EN patients had a hazard ratio of 14.63 (95% CI 8.58-24.91) compared with EN patients. The GCS score during the first 7 ICU days was significantly improved among EN patients with GCS scores of 6-8 compared with EN patients with GCS scores of 4-5 and non-EN patients with GCS scores of 6-8. This finding demonstrates that EN within 48 h post-injury is associated with better survival, GCS recovery, and outcome among sTBI patients, particularly in those with a GCS score of 6-8.

Enteral nutrition in patients with severe traumatic brain injury: reasons for intolerance and medical management

Approximately, 50% of patients with severe traumatic brain injury (TBI) exhibit intolerance to enteral nutrition (EN). This intolerance hampers the survival and rehabilitation of this subpopulation to a great extent, and poses various difficulties for clinicians due to its complex underlying mechanisms. This review discusses the possible reasons for intolerance to EN following severe TBI, current trends in medical management, as well as other related issues that are experienced by many clinicians.

Sickness behaviors following medial frontal cortical contusions in male rats

Behaviors associated with sickness (food consumption, weight maintenance, exploratory activity and grooming frequency) were examined on post-surgical days 1, 3, 5, 7 and 9 in male rats treated with progesterone (4 mg/kg) and/or vehicle. Rats with medial frontal cortex contusions showed reduced food consumption on days 1 and 3 (p < 0.01), reduced weight maintenance on days 1, 3, 5, 7 and 9 (p < 0.01), reduced grooming frequency on day 1 (p < .01), and reduced exploratory activity on day 1 (p < 0.01), after injury compared to sham rats. Contusion induced behaviors were not attenuated with 5 days of progesterone treatment (p > 0.05). Progesterone did reduce lesion size at 9 days after injury (p < 0.05). Our results suggest sickness behaviors occur after traumatic brain injury and that they might not respond to some neurosteroidal agents.

Hypogonadism on admission to acute rehabilitation is correlated with lower functional status at admission and discharge

PRIMARY OBJECTIVE

To investigate the association between hormone levels and functional status during acute TBI rehabilitation.

RESEARCH DESIGN

Retrospective cohort study of 43 men with moderate-to-severe TBI admitted to an acute rehabilitation unit during a 1 year period.

METHODS AND PROCEDURES

Labs were drawn on admission, including total and free testosterone (T), prolactin, adrenocorticotropin hormone (ACTH), cortisol, thyroid stimulating hormone (TSH), free thyroxine (fT4) and insulin-like growth factor (IGF-1). Functional Independence Measure (FIM) scores were obtained at admission and discharge.

MAIN OUTCOME AND RESULTS

Associations between admission hormone levels and the main outcomes, admission and discharge FIM scores, were assessed using linear regression. Lower total and free T-levels at admission were associated with lower total FIM scores at admission (p < 0.038) and discharge (p < 0.046). Higher cortisol levels at admission were significantly associated with lower admission (p = 0.012) and discharge (p = 0.036) scores on the cognitive-FIM. Prolactin, TSH, fT4 and IGF-1 were not correlated with functional status.

CONCLUSIONS

In men, lower total and free T-levels at admission to acute rehabilitation correlate with lower admission and discharge FIM scores. These data support the need for studies to investigate the impact of physiological testosterone therapy on outcomes during and post-rehabilitation.

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.

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.