Nutrition Therapy, Glucose Control, and Brain Metabolism in Traumatic Brain Injury: A Multimodal Monitoring Approach.

The goal of neurocritical care in patients with traumatic brain injury (TBI) is to prevent secondary brain damage. Pathophysiological mechanisms lead to loss of body mass, negative nitrogen balance, dysglycemia, and cerebral metabolic dysfunction. All of these complications have been shown to impact outcomes. Therapeutic options are available that prevent or mitigate their negative impact. Nutrition therapy, glucose control, and multimodality monitoring with cerebral microdialysis (CMD) can be applied as an integrated approach to optimize systemic immune and organ function as well as adequate substrate delivery to the brain. CMD allows real-time bedside monitoring of aspects of brain energy metabolism, by measuring specific metabolites in the extracellular fluid of brain tissue. Sequential monitoring of brain glucose and lactate/pyruvate ratio may reveal pathologic processes that lead to imbalances in supply and demand. Early recognition of these patterns may help individualize cerebral perfusion targets and systemic glucose control following TBI. In this direction, recent consensus statements have provided guidelines and recommendations for CMD applications in neurocritical care. In this review, we summarize data from clinical research on patients with severe TBI focused on a multimodal approach to evaluate aspects of nutrition therapy, such as timing and route; aspects of systemic glucose management, such as intensive vs. moderate control; and finally, aspects of cerebral metabolism. Research and clinical applications of CMD to better understand the interplay between substrate supply, glycemic variations, insulin therapy, and their effects on the brain metabolic profile were also reviewed. Novel mechanistic hypotheses in the interpretation of brain biomarkers were also discussed. Finally, we offer an integrated approach that includes nutritional and brain metabolic monitoring to manage severe TBI patients.

Energy Expenditure in Critically Ill Elderly Patients: Indirect Calorimetry vs Predictive Equations.

BACKGROUND: Predictive equations (PEs) are used for estimating resting energy expenditure (REE) when the measurements obtained from indirect calorimetry (IC) are not available. This study evaluated the degree of agreement and the accuracy between the REE measured by IC (REE-IC) and REE estimated by PE (REE-PE) in mechanically ventilated elderly patients admitted to the intensive care unit (ICU). METHODS: REE-IC of 97 critically ill elderly patients was compared with REE-PE by 6 PEs: Harris and Benedict (HB) multiplied by the correction factor of 1.2; European Society for Clinical Nutrition and Metabolism (ESPEN) using the minimum (ESPENmi), average (ESPENme), and maximum (ESPENma) values; Mifflin-St Jeor; Ireton-Jones (IJ); Fredrix; and Lührmann. Degree of agreement between REE-PE and REE-IC was analyzed by the interclass correlation coefficient and the Bland-Altman test. The accuracy was calculated by the percentage of male and/or female patients whose REE-PE values differ by up to ±10% in relation to REE-IC. RESULTS: For both sexes, there was no difference for average REE-IC in kcal/kg when the values obtained with REE-PE by corrected HB and ESPENme were compared. A high level of agreement was demonstrated by corrected HB for both sexes, with greater accuracy for women. The best accuracy in the male group was obtained with the IJ equation but with a low level of agreement. CONCLUSIONS: The effectiveness of PEs is limited for estimating REE of critically ill elderly patients. Nonetheless, HB multiplied by a correction factor of 1.2 can be used until a specific PE for this group of patients is developed.

Ventilaçäo com suporte pressórico e volume garantido (VAPSV): análise clínica inicial de 10 pacientes com insuficiência respiratória aguda de diferentes etiologias / Volume assured pressure support ventilation (VAPSV): early clinical analysis of 10 patients with acute respiratory failure of different aetiologies

A necessidade e o tipo de suporte ventilatório estäo relacionados diretamente com o mecanismo fisiopatológico da Insuficiência Respiratória Aguda. Atualmente, consideramos que o correto manuseio da interface paciente-ventilador tem implicaçöes de impacto no curso e prognóstico da falência respiratória. A ventilaçäo por controle de volume (VCV) é a modalidade mais empregada de suporte ventilatório, sendo de grande valia na maior parte dos casos de Insuficiência Respiratória. A ventilaçäo por controle de pressäo (PCV), apesar de sua maior limitaçäo (Volume corrente vari vel), tem sido empregada como alternativa bem sucedida para ventilaçäo de pacientes com SARA. Ultimamente, diversos escolas tentaram combinar as melhores características de ambas modalidades (VCV e PCV), dando surgimento a novas técnicas de suporte ventilatório denominadas genericamente de ventilaçäo em alça fechada, delas, destacamos a ventilaçäo com suporte pressórico e volume garantido (VAPSV). Neste artigo descrevemos a experiência clínica inicial com o emprego da VAPSV no CTI do Hospital dos Servidores do Estado, MS-SUS, RJ.