Neurologic Assessment of the Neurocritical Care Patient

Sedation is a ubiquitous practice in ICUs and NCCUs. It has the benefit of reducing cerebral energy demands, but also precludes an accurate neurologic assessment. Because of this, sedation is intermittently stopped for the purposes of a neurologic assessment, which is termed a neurologic wake-up test (NWT). NWTs are considered to be the gold-standard in continued assessment of brain-injured patients under sedation. NWTs also produce an acute stress response that is accompanied by elevations in blood pressure, respiratory rate, heart rate, and ICP. Utilization of cerebral microdialysis and brain tissue oxygen monitoring in small cohorts of brain-injured patients suggests that this is not mirrored by alterations in cerebral metabolism, and seldom affects oxygenation. The hard contraindications for the NWT are preexisting intracranial hypertension, barbiturate treatment, status epilepticus, and hyperthermia. However, hemodynamic instability, sedative use for primary ICP control, and sedative use for severe agitation or respiratory distress are considered significant safety concerns. Despite ubiquitous recommendation, it is not clear if additional clinically relevant information is gleaned through its use, especially with the contemporaneous utilization of multimodality monitoring. Various monitoring modalities provide unique and pertinent information about neurologic function, however, their role in improving patient outcomes and guiding treatment plans has not been fully elucidated. There is a paucity of information pertaining to the optimal frequency of NWTs, and if it differs based on type of injury. Only one concrete recommendation was found in the literature, exemplifying the uncertainty surrounding its utility. The most common sedative used and recommended is propofol because of its rapid onset, short duration, and reduction of cerebral energy requirements. Dexmedetomidine may be employed to facilitate serial NWTs, and should always be used in the non-intubated patient or if propofol infusion syndrome (PRIS) develops. Midazolam is not recommended due to tissue accumulation and residual sedation confounding a reliable NWT. Thus, NWTs are well-tolerated in selected patients and remain recommended as the gold-standard for continued neuromonitoring. Predicated upon one expert panel, they should be performed at least one time per day. Propofol or dexmedetomidine are the main sedative choices, both enabling a rapid awakening and consistent NWT.

Unilateral posterior reversible encephalopathy syndrome characterized with a long and gradually exacerbating course over 3 years and that presented propofol infusion syndrome – A case report

Background: Posterior reversible encephalopathy syndrome (PRES) is characterized by acute neurological symptoms and vasogenic edema, and most patients wholly recover. We report a unilateral PRES patient characterized by a gradual onset followed by propofol infusion syndrome (PRIS) due to general anesthesia therapy. Case Description: A 32-year-old woman had ovarian dysfunction treated by Kaufmann’s treatment for 17 years. Three years ago, she developed seizures, and photophobia and myoclonus sometimes occurred. This time, she had strong photophobia and nausea for 3 months and then developed tonic-clonic seizures for 3 min. Her blood pressure and laboratory test on admission were all within normal limits. She presented no neurological deficits at admission, but the T2-weighted image (T2WI) showed a high-intensity area (HIA), and arterial spin labeling (ASL) image described cerebral blood flow (CBF) increase in the left parieto-occipital region. We diagnosed PRES and started anticonvulsants, antihypertensive, and steroid pulse therapy. However, her aphasia and neuroimaging findings worsened, so we started general anesthesia treatment with propofol on day 29. On day 32, she suddenly developed multiple organ dysfunctions due to PRIS. After intensive care with other sedatives over 2 months, the systemic status and neurological symptoms gradually improved almost as before the onset. On day 90, HIA in the T2WI in the lesion became small, and CBF was severely downregulated in the ASL image. Conclusion: Unilateral PRES’s pathophysiology and the association with the female hormone remain unknown. Some patients undergo gradual onset and long-term courses, and we should care for PRIS during PRES treatment.

Use of Dexmedetomidine as an Adjuvant to Propofol along with Neurophysiological Monitoring of the Seventh Cranial Nerve during Cerebello- Pontine Tumour Excision Surgery

Cerebello‑Pontine Angle (CPA) surgeries are very challenging for neurosurgeons as it lies very close to brain stem so various cranial nerves are at risk of damage. Generally, such surgeries require neuromuscular monitoring of various cranial nerves. For that we have to discontinue neuromuscular blocking agents and inhalational agents. Total Intravenous Anaesthesia (TIVA) avoids the use of neuromuscular blocking agents as well as inhalational agents. However, prolonged infusion of propofol is associated with risks, such as hypotension, delayed awakening, and metabolic acidosis, known as “Propofol Infusion Syndrome”. Dexmedetomidine now‑a‑days is used very commonly as an adjuvant to propofol and it significantly reduces the anaesthetic requirement. Addition of dexmedetomidine provides haemodynamic stability during such neurosurgeries. Here, authors have described anaesthetic management of a 46‑year‑old female patient posted for CPA excision along with seventh cranial nerve monitoring using dexmedetomidine with propofol.

Neurologic Assessment of the Neurocritical Care Patient: The Neurologic Wake-Up Test

Sedation is a ubiquitous practice in ICUs and NCCUs. It has the benefit of reducing cerebral energy demands, but also precludes an accurate neurologic assessment. Because of this, sedation is intermittently stopped for the purposes of a neurologic assessment, which is termed a neurologic wake-up test (NWT). NWTs are considered to be the gold-standard in continued assessment of brain-injured patients under sedation. NWTs also produce an acute stress response that is accompanied by elevations in blood pressure, respiratory rate, heart rate, and ICP. Utilization of cerebral microdialysis and brain tissue oxygen monitoring indicates that this is not mirrored by alterations in overall cerebral metabolism, and seldom affects oxygenation. The hard contraindications for the NWT are preexisting intracranial hypertension, barbiturate treatment, status epilepticus, and hyperthermia. However, hemodynamic instability, sedative use for primary ICP control, and sedative use for severe agitation or respiratory distress are considered significant safety concerns. Despite ubiquitous recommendation, it is not clear if additional clinically relevant information is gleaned through its use, especially with the contemporaneous utilization of multimodality monitoring. Various monitoring modalities provide unique and pertinent information about neurologic function, however, their role in improving patient outcomes and guiding treatment plans has not been fully elucidated. There is a paucity of information pertaining to the optimal frequency of NWTs, and if it differs based on type of injury. Only one concrete recommendation was found in the literature, exemplifying the uncertainty surrounding its utility. The most common sedative used and recommended is propofol because of its rapid onset, short duration, and reduction of cerebral energy requirements. Dexmedetomidine may be employed to facilitate serial NWTs, and should always be used in the non-intubated patient or if propofol infusion syndrome (PRIS) develops. Midazolam is not recommended due to tissue accumulation and residual sedation confounding a reliable NWT. Thus, NWTs are well tolerated in most patients and remain recommended as the gold-standard for continued neuromonitoring. Predicated upon one expert panel, they should be performed at least one time per day. Propofol or dexmedetomidine are the main sedative choices, both enabling a rapid awakening and consistent NWT.

Propofol Infusion Syndrome: A Life Threatening Condition Blunted by Continuous Renal Replacement Therapy

Propofol is a common intensive care unit anesthetic which was approved by FDA in 1989. It possesses sedative, anxiolytic, and anticonvulsant properties. Case reports of Propofol related infusion syndrome (PRIS) started in early 1990s. Reported signs and symptoms included acute refractory bradycardia, severe metabolic acidosis, cardiovascular collapse, lactic acidosis, rhabdomyolysis, hyperlipidemia, renal failure, and hepatomegaly. It is associated with both high dose cumulative and short-term infusions. This case report highlights the development of PRIS in a patient admitted to the ICU, symptoms of which were assumed to be blunted because of continuous renal replacement therapy support.