Insulin and the Brain: A Sweet Relationship With Intensive Care.

BACKGROUND: Insulin receptors (IRs) in the brain have unique molecular features and a characteristic pattern of distribution. Their possible functions extend beyond glucose utilization. In this systematic review, we explore the interactions between insulin and the brain and its implications for anesthesiologists, critical care physicians, and other medical disciplines. METHODS: A literature search of published preclinical and clinical studies between 1978 and 2014 was conducted, yielding 5996 articles. After applying inclusion and exclusion criteria, 92 studies were selected for this systematic review. RESULTS: The IRs have unique molecular features, pattern of distribution, and mechanism of action. It has effects on neuronal function, metabolism, and neurotransmission. The IRs are involved in neuronal apoptosis and neurodegenerative processes. CONCLUSION: In this systematic review, we present a close relationship between insulin and the brain, with discernible effects on memory, learning abilities, and motor functions. The potential therapeutic effects extend from acute brain insults such as traumatic brain injury, brain ischemia, and hemorrhage, to chronic neurodegenerative diseases such as Alzheimer and Parkinson disease. An understanding of the wider effects of insulin conveyed in this review will prompt anaesthesiologists and critical care physicians to consider its therapeutic potential and guide future studies.

Postoperative delirium: risk factors, diagnosis and perioperative care.

UNLABELLED: Postoperative delirium (PD) relates to increased morbidity -associated with prolonged hospital stay, institutionalization and persistent functional and cognitive decline- poor long term outcome and higher perioperative mortality. Aim of this literature review is to identify established risk factors for PD and to categorize them according timing of occurrence (pre, intra and post operative), and clinical impact (Odds ratio [OR], % increase in incidence of PD). SOURCE OF INFORMATION: medical literature databases (medline and embase) were searched for published manuscripts on "postoperative delirium". Predictors and preoperative risk factors for PD were categorized into 4 groups: demographics; co morbidities; surgery and anesthesia-related (age, education, laboratory anomalies, smoking habits, benzodiazepines premedication, cardiac and thoracic surgery, etc). Intra operative risk factors for PD were categorized into 2 groups: surgery and anesthesia-related (anemia, duration and type of surgery, selected opioid, intraoperative hypotension, etc). Post operative risk factors and precipitating factors include various pathophysiological and environmental conditions, (i.e., ICU admission, low cardiac output requiring inotropes infusion; new onset atrial fibrillation; persistent hypoxia or hypercarbia; use of narcotic analgesics, delayed ambulation, inadequate nutritional status; sensory deprivation, etc). In conclusion, the effective identification, prevention and treatment of pre, intra and postoperative risk factors are the cornerstones for the prevention of PD. A dedicated perioperative care path that encompasses a tailored selection of drugs used perioperatively, the appropriate anesthesia strategy, qualified nursing surveillance, systematic use of diagnostic tools and accurate staff communication reduces the incidence and clinical impact of PD.

Assessment of NGAL as an early biomarker of acute kidney injury in adult cardiac surgery patients.

Early and predictive acute kidney injury (AKI) markers may be decisive for the clinical outcome of heart surgery. Hence, this study set out to evaluate the biological variability of urinary neutrophil gelatinase-associated lipocalin (uNGAL) levels in adult cardiac surgery patients, to test their feasibility as a biomarker of early AKI in a routine laboratory setting. uNGAL levels were measured with an automated immunoassay in urine samples from patients undergoing cardiac surgery using cardiopulmonary bypass, at the time of admission (T0) and 4 hours (T1) and 24 hours (T2) after surgery. Patients without post-operative AKI did not show significant differences in urine NGAL levels after surgery. In contrast, patients developing AKI displayed a significant increase (P=0.011) in uNGAL levels compared to T0. This increase was detectable at an earlier time point (T1, 4 hours) with respect to serum creatinine (T2, 24 hours). Confirming its utility as a biomarker, at T1 the uNGAL levels were significantly higher in AKI patients than in non-AKI patients (P=0.021). A receiver operating characteristic curve analysis of the uNGAL assay gave a sensitivity of 55.3 (95percent confidence interval, 26.59-78.73), a specificity of 72.9 (95 percent CI, 55.88-86.21), and a cut-off value for AKI prediction of 55.2. These results support the notion that urinary NGAL is an earlier marker of AKI than serum creatinine. However, the cut-off value of the assay was too low to consider it as a positive or negative diagnostic marker in AKI patients with moderate degree of severity. Likewise, its sensitivity and specificity were not high enough for it to be considered better than the others currently in use.