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Positions in neurosurgery
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Geriatric Neuroanesthesia, 2019
Zilvinas Zakarevicius, Mikhail Gelfenbeyn, Irene Rozet
This maneuver often causes hemodynamic instability due to decreased venous return, leading to decreased stroke volume with subsequent decrease in mean systemic and pulmonary arterial pressure and increase in systemic and pulmonary resistance (39). Jugular veins are usually collapsed, and venous outflow is dependent on the vertebral circulation (40). Although cerebral oxygenation may initially decrease, reflecting decrease of cardiac output (41), cerebral oxygenation normalizes with stabilization of hemodynamics (42). If osmotherapy is required, the preference should be given to hypertonic saline due to less diuretic effect (43) and better preservation of cardiac output compared to mannitol (44). Maintenance of normovolemia, fluid boluses, use of compression devices on the legs (45), and slow, incremental adjustment of table position may prevent an abrupt hemodynamic instability.
Head injury
Published in Ian Greaves, Keith Porter, Chris Wright, Trauma Care Pre-Hospital Manual, 2018
Ian Greaves, Keith Porter, Chris Wright
Hypertonic saline (HS) can also be used for osmotherapy. The principle effect on ICP is thought to be due to osmotic mobilisation of water across the intact blood-brain barrier, which reduces cerebral water content. Effects on the microcirculation may also have a role. HS dehydrates endothelial cells and erythrocytes, which increases the diameter of the vessels and deformability of erythrocytes and leads to plasma volume expansion with improved blood flow. It was thought that HS would benefit patients with TBI, as it has the potential to preserve or even improve haemodynamic parameters. However, current evidence is not strong enough to make recommendations on the use, concentration and method of administration of HS. Consequently, in adults there is insufficient evidence to support the use of HS over mannitol for osmotherapy at present (9,14).
Geriatric neurotrauma
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Anesthesia for Neurotrauma, 2018
Osmotherapy may be initiated or continued during surgery. Mannitol is typically used in doses between 0.25 and 1 g/kg. Its brain dehydrating effect requires an intact blood–brain barrier. It causes initial hypervolemia and subsequent diuresis. The latter should be replaced by normal saline to maintain euvolemia. Serum osmolality may be monitored during mannitol administration. If serum osmolality becomes greater than 320 mOsm/L, mannitol should be discontinued unless the osmolar gap is less than 15. Hypertonic saline (2%, 3%, or 23.4%) can be used to reduce brain edema and ICP. Saline concentrations more than 3% should be infused through a central venous catheter. Hypertonic saline has been reported to be superior to mannitol for reducing ICP, and maintaining intravascular osmolarity.
An update on the pharmacological management and prevention of cerebral edema: current therapeutic strategies
Published in Expert Opinion on Pharmacotherapy, 2021
Melissa Pergakis, Neeraj Badjatia, J. Marc Simard
Cerebral edema contributes to a high degree of morbidity and mortality in LHI, contusion TBI, and other neurologic disease states. Osmotherapy remains one of the sole pharmacologic agents for treatment of cerebral edema and is largely unproven with regards to clinical outcome. Additionally, it does not change the underlying cause of cerebral edema at the pathophysiologic level. Important work has been done in recent years expanding our knowledge and understanding of edema in the central nervous system. We move away from archaic classifications of cerebral edema as simply cytotoxic or vasogenic to include ionic edema with a new appreciation of the multiple channels and ion transporters involved. With a more sophisticated understanding of the underlying pathophysiology of cerebral edema including ion transporters, channels, and receptors upregulated and expressed during edema formation as well as the temporal relation after CNS injury, the unique opportunity to alter the physiologic disease state exists.
New drugs on the horizon for cerebral edema: what’s in the clinical development pipeline?
Published in Expert Opinion on Investigational Drugs, 2020
Stephanie M. Robert, Benjamin C. Reeves, Seth L. Alper, Jinwei Zhang, Kristopher T. Kahle
Osmotherapy, a common first line management, consists of intravenous administration of hypertonic solution (typically mannitol or hypertonic saline). Following Starling’s principle, creating an osmotic gradient across blood vessels causes water to move from the intra- and extracellular compartments of the brain into the vasculature, decreasing parenchymal fluid volume. This movement of water along an imposed ionic gradient serves to decrease intracranial volume, and as a result, pressures. In addition to osmotherapy, the glucocorticoid Decadron is commonly used, especially in the setting of tumor-induced edema [4]. Other less commonly used medications for edema include loop diuretics (typically furosemide), anti-inflammatory agents, and barbiturates [5].
Quality And Feasibility of Sonographic Measurement of the Optic Nerve Sheath Diameter to Estimate the Risk of Raised Intracranial Pressure After Traumatic Brain Injury in Prehospital Setting
Published in Prehospital Emergency Care, 2019
Charles-Henri Houzé-Cerfon, Vincent Bounes, Johanna Guemon, Thibault Le Gourrierec, Thomas Geeraerts
Twenty-three patients were then finally enrolled in the study, with a median age of 53 (interquartile range [IQR] = 34.5; 66) years; 91% of patients were male (n = 21). The median Glasgow Coma Scale (GCS) on score scene was 4 [IQR 3; 11]. Sixty five percent (n = 15) of the patients were considering to have severe TBI (GCS <8) and were intubated and sedated (sufentanil and midazolam) during prehospital management. Pupil abnormalities were found in 26% (n = 6) of patients, with 5 anisocoria and one absence of pupillary light reflex. Osmotherapy was administered in 5 patients.