Comparison of the Effects of Deep and Moderate Neuromuscular Blockade on Optic Nerve Sheath Diameter...
Intracranial HypertensionIncreased intracranial pressure (IICP) is a common problem in traumatic brain injuries and many medical diseases. Early recognition of IICP can save lives. Several invasive and non-invasive methods have been described for IICP diagnosis. In recent years, ultrasonographic measurement of optic nerve sheath diameter (ONSD) has become a popular method due to its high sensitivity and specificity for IICP estimation. Studies have shown that ONSD's ultrasonographic measurement correlates with the IICP and can detect intracranial hypertension. The ONSD measurement has advantages such as being easily applied by the clinician at the bedside, being non-invasive, providing immediate results, reproducibility and low cost. It is known that artificial carbon dioxide pneumoperitoneum created in laparoscopic surgeries increases intracranial pressure.However, it is not easy to estimate the degree of changes in ICP during laparoscopic surgery under general anesthesia. In the literature, there are many studies on the sonographic measurement of optic nerve sheath diameter to evaluate the effects of trendelenburg position on intracranial pressure with the use of different anesthetic drugs in laparoscopic surgeries. In addition, there are studies reporting that deep neuromuscular blockade in laparoscopic surgeries increases surgical vision and decreases analgesic requirement in postoperative period. The relationship between neuromuscular block level and intracranial pressure is not clear. From this point of view, the investigators would like to evaluate the effect of moderate and deep neuromuscular block level on intracranial pressure by sonographic measurement of optic nerve sheath diameter in laparoscopic cholecystectomy operations performed with standard pressure artificial carbon dioxide pneumoperitoneum.
Ocular Point of Care Ultrasound (POCUS) to Detect Optic Disc Swelling in Comparison to Ophthalmologic...
Papilledema Associated With Increased Intracranial PressurePediatric emergency department (PED) physicians frequently encounter children with symptoms that warrant evaluation of the optic disc for suspected increased intracranial pressure (ICP) such as headache, blurred vision, recurrent vomiting etc. Fundoscopic examination, by the PED physician, is considered an essential modality for assessment of the optic disc and the diagnosis of papilledema. Obtaining good visualization of the optic disc requires patient compliance, the ability to open the eyelids, the absence of opacities in the ocular media and a sufficiently large pupillary aperture. Hence, different levels of PED physician training, lack of cooperation, significant ocular or periorbital trauma, contraindications to mydriasis and severe photophobia may hinder direct fundoscopic evaluation. In the investigators' PED, children requiring fundoscopy are sent to a formal ophthalmologic examination. The investigators aim to evaluate the yield of optic disc height as measured with ocular point of care ultrasound to detect optic disc swelling in comparison to ophthalmologic examination as the gold standard.
The Influence of Dexmedetomidine Hypnosis on Cerebrospinal Fluid (CSF) Volume, Brain Diffusion and...
Cerebrospinal Fluid Pressure IncreasedThe primary goal is to quantify cerebrospinal fluid (CSF) volume, diffusion characteristics and mechanical properties of brain tissue at two states of arousal.
The Hemodynamic Effects During Sustained Low-efficiency Dialysis Versus Continuous Veno-venous Hemofiltration...
End- Stage Renal Disease PatientsHemodynamic instability occurs frequently during dialysis treatment and still remains as significant cause of patient mobility and mortality. Postoperative hemodynamic optimization has been proved to reduce morbidity in high-risk patients. Intracranial pressure increased can lead to further structural and functional impairment owing to its deleterious effect on the compromised microcirculation and metabolism. This study was to compare the intra-cerebral pressure (ICP) and hemodynamic parameters between the sustained low-efficiency dialysis (SLED) and continuous veno-venous hemofiltration (CVVH) in post- brain tramatic patients.
Coagulation Activation by Hyperosmolar Agents in Intracranial Hypertension
Intracranial HypertensionCerebral EdemaOsmotherapy consists in the therapeutic use of osmotically active substances with the aim of reducing the volume and therefore the intracranial pressure. It therefore represents an essential component in the clinical management of cerebral edema and intracranial hypertension, whether they are a consequence of head trauma, ischemic or hemorrhagic stroke, and neoplasm or neurosurgical procedures. The current study aims at evaluating in vivo the effects on haemostasis parameters of hypertonic saline solutions at different concentration, as compared to mannitol, in patients with neuroradiological signs (CT / MRI) of cerebral edema / non-traumatic intracranial hypertension.
Optic Nerve Head Quantification While Reducing Elevated Intracranial Pressure
Intraocular PressureIntracranial HypertensionThe goal of this study is to examine in-vivo the effect of intraocular (IOP) and intracranial pressures (ICP) on the optic nerve head (ONH). The effect of ICP on eye health has been an area of concrete research effort in recent years. The ability to acquire non-invasive and highly detailed information on both the eye and the brain using technologies such as magnetic resonance imaging (MRI) and optical coherence tomography (OCT) have paved the way to assess non-invasively the effect of ICP in-vivo. In this study, we will quantify the structural changes in the ONH in subjects with elevated ICP while they are treated to reduce the elevated pressure. This process will occur in a stepwise fashion over a period of time determined by the clinical treatment plans. We will apply controlled pressures to the eye during each step of ICP lowering while OCT images are obtained.
Importance of Substance P in Intracranial Pressure Elevation Following Traumatic Brain Injury
Traumatic Brain InjuryTraumatic brain (TBI) injury is the major cause of morbidity and mortality worldwide especially in population under 40 years of age and has a significant socioeconomic impact. TBI results from the head impacting with an object or from acceleration/deceleration forces that produce vigorous movement of the brain within the skull, with the resultant mechanical forces potentially damaging neurones and blood vessels and causing irreversible, primary brain injury. Primary injury leads to activation of cellular and molecular responses which lead to disruption of the blood-brain barrier causing the brain to swell. As the intracranial space is not expandable (i.e. is fixed), this swelling leads to increase in intracranial pressure (ICP) compromising blood supply to the rest of the brain leading to secondary brain injury. As we are unable to reverse the primary injury, current protocols use supportive measures to control the ICP and ensure optimal blood supply to the brain in an attempt to minimize secondary injury. Our understanding of the factors involved in the initiation and propagation of brain swelling in TBI is growing and the role of neuroinflammatory cytokines in this process is increasingly recognized. In preclinical models of TBI, a specific inflammatory cytokine termed substance P (SP) is found to be associated with blood-brain barrier disruption and development of brain oedema in the immediate phase following injury. The aim of this study is to examine the role of SP in the genesis of cerebral oedema and elevation of ICP and thus secondary injury following human TBI. This would be achieved by blocking SP function with a SP receptor antagonist Fosaprepitant (IVEMEND®, Merck) in the first 24 hours following TBI and then continuously measuring ICP and assessing the evolvement of TBI using magnetic resonance imaging.
Dexmedetomidine on Optic Nerve Sheath Diameter
Intracranial HypertensionDexmedetomidine, might attenuate the sympathetic activation and contribute to stable hemodynamics. The investigator hypothesized that continuous infusion of dexmedetomidine during laparoscopic lower abdominal surgery, might help to attenuate the increment of intracranial pressure and the investigator would observe the optic nerve sheath diameter using ultrasonography.
OCT Imaging of Papilledema in Pediatric Idiopathic Intracranial Hypertension
Pediatric Idiopathic Intracranial HypertensionLongitudinal clinical observation of optic nerve head, using slit lamp fundoscopy, guides therapy in pediatric idiopathic intracranial hypertension (IIH) patients; however, it remains a limited method of producing quantitative data in evaluating in patients with IIH. In this study we intend to compare, by using spectral domain optical coherence tomography (OCT), the mean retinal nerve fiber layer thickness and total retinal thickness (RNFLT/TRT) of the optic nerve of newly diagnosed IIH children to a control group. This will provide a quantitative measure for follow-up and treatment of this patient group.
Optic Nerve Sheath Diameter in Patients With Intracranial Pathology
Elevated Intracranial Pressure (ICP)Elevated intracranial pressure (ICP) is a common and potentially life threatening condition arising from a variety of pathological conditions. The ability to monitor ICP is a crucial aspect in the management of these patients. Currently, the diagnosis of whether ICP is elevated or not is determined either with clinical signs (headache, nausea and vomiting or visual disturbances) or from the changes in the preoperative neuroimaging modalities such as computerized tomography (CT scan) and/or magnetic resonance imaging (MRI). Recently, transorbital ultrasonography has gained popularity as a noninvasive bedside exam that has been shown to be useful in the diagnosis of raised ICP by evaluating the change in the optic nerve sheath diameter (ONSD). The aim of our study is to use transorbital ultrasound to evaluate ONSD changes in patients with intracranial pathology and to compare the changes in the ONSD before and after surgical intervention as well as between patients with and without clinical or radiological signs of increased ICP.