Neurocritical care
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In comatose post-cardiac arrest patients, a serum neuron-specific enolase (NSE) level of >33 μg/L within 72 h was identified as a reliable marker for poor outcome in a large Dutch study (PROPAC), and this level was subsequently adopted in an American Academy of Neurology practice parameter. Later studies reported that NSE >33 μg/L is not a reliable predictor of poor prognosis. To test whether different clinical laboratories contribute to this variability, we compared NSE levels from the laboratory used in the PROPAC study (DLM-Nijmegen) with those of our hospital's laboratory (ARUP) using paired blood samples. ⋯ Absolute serum NSE levels of comatose cardiac arrest patients differ between laboratories. Any specific absolute cut-off levels proposed to prognosticate poor outcome should not be used without detailed data on how neurologic outcomes correspond to a particular laboratory's method, and even then only in conjunction with other prognostic variables.
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The core challenge of pain management in neurocritical care is to keep the patient comfortable without masking or overlooking any neurological deterioration. Clearly in patients with a neurological problem there is a conflict of clinical judgement and adequate pain relief. Here we review the presentation, assessment, and development of pain in the clinical spectrum of patients with associated neurological problems seen in a general intensive care setting. ⋯ There is evidence that swift and targeted pain management may improve the outcome. Importantly pain management is multidisciplinary. The available non-invasive, pharmacological, and invasive treatment strategies are discussed.
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As important mediators of solute transport at the blood-brain and blood-cerebrospinal fluid barriers, ATP-binding cassette (ABC) transporters (including ABCB1, ABCC1, and ABCC2), impact the bioavailability of drugs and endogenous substrates in the brain. While several ABCB1, ABCC1, and ABCC2 single nucleotide polymorphisms (SNPs) have been identified, their impact on outcome after traumatic brain injury (TBI) is unknown. ⋯ In this single-center study, patients homozygous for the T allele of ABCB1 rs1045642 or the G allele of ABCC1 rs4148382 were found to have better outcome after severe TBI. Further study is necessary to replicate these very preliminary findings and to determine whether these associations are due to central nervous system bioavailability of ABC transporter drug substrates commonly used in the management of TBI, brain efflux of endogenous solutes, or both.
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    Observational Study
Impact of methamphetamine on regional metabolism and cerebral blood flow after traumatic brain injury.
Substance abuse is a frequent comorbid condition among patients with traumatic brain injury (TBI), but little is known about its potential additive or interactive effects on tissue injury or recovery from TBI. This study aims to evaluate changes in regional metabolism and cerebral perfusion in subjects who used methamphetamine (METH) prior to sustaining a TBI. We hypothesized that METH use would decrease pericontusional cerebral perfusion and markers of neuronal metabolism, in TBI patients compared to those without METH use. ⋯ This small study demonstrates that tissue metabolism is regionally heterogeneous after TBI and pericontusional perfusion was significantly reduced in the METH subgroup.
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Although cardiac abnormalities are well described among patients with acute brain injury, they have not been investigated systematically for acute subdural hemorrhage (SDH). We sought to investigate the prevalence and characteristics of cardiac abnormalities in patients with SDH. ⋯ Although we found ECG abnormalities to be common in patients with SDH, they were not associated with SDH characteristics, and classic neurogenic findings were not observed. Myocardial injury was infrequent and not associated with SDH characteristics. While cardiac abnormalities in acute intracerebral injury often are attributed to neurocardiogenic causes, these are unlikely prominent mechanisms in SDH. Other medical causes need to be considered, as this will have important implications for management.