36 research outputs found
Somatosensory Evoked Potentials suppression due to remifentanil during spinal operations; a prospective clinical study
<p>Abstract</p> <p>Background</p> <p>Somatosensory evoked potentials (SSEP) are being used for the investigation and monitoring of the integrity of neural pathways during surgical procedures. Intraoperative neurophysiologic monitoring is affected by the type of anesthetic agents. Remifentanil is supposed to produce minimal or no changes in SSEP amplitude and latency. This study aims to investigate whether high doses of remifentanil influence the SSEP during spinal surgery under total intravenous anesthesia.</p> <p>Methods</p> <p>Ten patients underwent spinal surgery. Anesthesia was induced with propofol (2 mg/Kg), fentanyl (2 mcg/Kg) and a single dose of cis-atracurium (0.15 mg/Kg), followed by infusion of 0.8 mcg/kg/min of remifentanil and propofol (30-50 mcg/kg/min). The depth of anesthesia was monitored by Bispectral Index (BIS) and an adequate level (40-50) of anesthesia was maintained. Somatosensory evoked potentials (SSEPs) were recorded intraoperatively from the tibial nerve (P37) 15 min before initiation of remifentanil infusion. Data were analysed over that period.</p> <p>Results</p> <p>Remifentanil induced prolongation of the tibial SSEP latency which however was not significant (p > 0.05). The suppression of the amplitude was significant (p < 0.001), varying from 20-80% with this decrease being time related.</p> <p>Conclusion</p> <p>Remifentanil in high doses induces significant changes in SSEP components that should be taken under consideration during intraoperative neuromonitoring.</p
The Potential of microRNAs for Stem Cell-based Therapy for Degenerative Skeletal Diseases
Purpose of review: degenerative skeletal disorders including osteoarthritis (OA) and osteoporosis (OP) are the result of attenuation of tissue regeneration and lead to painful conditions with limited treatment options. Preventative measures to limit the onset of OA and OP remain a significant unmet clinical need. MicroRNAs (miRNAs) are known to be involved in the differentiation of stem cells, and in combination with stem cell therapy could induce skeletal regeneration and potentially prevent OA and OP onset.Recent findings: the combination of stem cells and miRNA has been successful at regenerating the bone and cartilage in vivo. MiRNAs, including miR-146b known to be involved in chondrogenic differentiation, could provide innovative targets for stem cell-based therapy, for the repair of articular cartilage defects forestalling the onset of OA or in the generation of a stem cell-based therapy for OP.Summary: this review discusses the combination of skeletal stem cells (SSCs) and candidate miRNAs for application in a cell-based therapy approach for skeletal regenerative medicine
Neurophysiological investigations of hepatic encephalopathy: ISHEN practice guidelines
Abstract
By studying neuronal activity through neuronal electrogenesis, neurophysiological investigations provide a functional assessment of the nervous system and, therefore, has been used for quantitative assessment and follow-up of hepatic encephalopathy (HE). The different clinical neurophysiological approaches can be classified depending on the function to explore and their sensitivity to HE. The reliable techniques are those that reflect cortical function, i.e., cognitive-evoked potentials (EPs) (P300 paradigm), electroencephalogram (EEG), visual EPs (latency>100 ms) and somatosensory EPs (SEPs) (latency between 25 and 100 ms). Short-latency EPs (brainstem acoustic EPs, SEPs of a latency<25 ms) are in principle insensitive to HE, but can disclose brainstem conduction deficits due to oedema. SEPs and motor EPs can disclose myelopathies. Because of its parallelism to the clinical examination, clinical neurophysiology can complement the neurological examination: (i) to provide evidence of HE in patients who have normal consciousness; (ii) to rule out, at least under some conditions, disturbances of consciousness due to other causes (e.g. drug-induced disturbances, non-convulsive status epilepticus) with the reservation that the mildest degrees of encephalopathy might be associated with an EEG pattern similar to that induced by drugs; and (iii) to demonstrate the worsening or, conversely improvement, of HE in the follow-up period
Prospective Cohort Study Evaluating the Prognostic Value of Simple EEG Parameters in Postanoxic Coma
Neurophysiological testing in neurocritical care.
Purpose of review
To summarize a consensus of European authorities about the applications of clinical
neurophysiology in the ICU and, particularly, for a clinically useful management of
individual patients.
Recent findings
Clinical neurophysiology is useful for diagnosis (epilepsy, brain death, and
neuromuscular disorders), prognosis (anoxic ischemic encephalopathy, head trauma,
and neurological disturbances of metabolic and toxic origin), and follow-up. The
prognostic significance of each test varies as a function of coma etiology. A distinction
should be made between tests whose abnormalities are indicative of a poor prognosis
(bilateral absence of N20 in anoxic coma, abnormalities suggesting pontine involvement
in head trauma) and those whose relative normalcy constitutes an argument for a good
prognosis (integrity of brainstem conductions in head trauma, presence of cognitive
evoked potentials \u2013 mismatch negativity, P300 \u2013 irrespective of coma etiology).
The highlights of the recent literature mainly concern continuous neuromonitoring for
early detection of nonconvulsive seizures, both in adult and neonatal ICU, brain entry
into the ischemic penumbra zone, and neuronal functional consequences of intracranial
hypertension.
Summary
The domain of clinical neurophysiology is similar to that of clinical examination and
complementary to that of imaging techniques. It substantially improves the individual
management of ICU patients