Practice Of Neurocritical Care Research Articles

Critical Care of Brain Reperfusion.

Over the last few decades, the management of acute ischemic stroke has undergone significant advancements with the introduction of intravenous thrombolysis and more recently punctuated by the success of endovascular mechanical thrombectomy trials for large vessel occlusion. These advancements have transformed the practice of neurocritical care. In this review, we present a case-based discussion of common brain reperfusion techniques with an emphasis on complication recognition and management. The article encompasses recent evidence-based recommendations as well as some of our own institutional protocols.

Transcranial Doppler ultrasonography: From methodology to major clinical applications.

Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler (TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency (≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called "paradoxical embolism", most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called "microembolic signal grading score". In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage (caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.

Clinical challenges of endocrinological origin in neurocritical care practice

Certain endocrinological disorders are a frequent finding in neurosurgical patients admitted in the neurocritical care units and these disorders have a deleterious bearing in the overall course of the illness and the final outcome. Alteration of neurotransmitters release responsible for maintaining the hormonal homeostasis is the presumable explanation of these disorders. The anatomical nearness of vital centers controlling the release of neurotransmitters and the site of lesion alters the normal pattern of the release and affecting the normal homeostasis thereby leading to adverse consequences on the other organ systems. The anatomical proximity to the vital centres regulating the endocrinological physiology and alteration in the neurotransmitter release causes disturbances in the hormonal homeostasis. Thus, an indepth understanding and early recognition of the clinical changes is necessary so as to arrest the further progress of the endocrine abnormality and to commence early remedial measures.

Windowed multitaper correlation analysis of multimodal brain monitoring parameters.

Although multimodal monitoring sets the standard in daily practice of neurocritical care, problem-oriented analysis tools to interpret the huge amount of data are lacking. Recently a mathematical model was presented that simulates the cerebral perfusion and oxygen supply in case of a severe head trauma, predicting the appearance of distinct correlations between arterial blood pressure and intracranial pressure. In this study we present a set of mathematical tools that reliably detect the predicted correlations in data recorded at a neurocritical care unit. The time resolved correlations will be identified by a windowing technique combined with Fourier-based coherence calculations. The phasing of the data is detected by means of Hilbert phase difference within the above mentioned windows. A statistical testing method is introduced that allows tuning the parameters of the windowing method in such a way that a predefined accuracy is reached. With this method the data of fifteen patients were examined in which we found the predicted correlation in each patient. Additionally it could be shown that the occurrence of a distinct correlation parameter, called scp, represents a predictive value of high quality for the patients outcome.

Monitoring in Neurointensive Care - The Challenge to Detect Delayed Cerebral Ischemia in High-Grade Aneurysmal SAH.

Delayed cerebral ischemia (DCI) is a feared and significant medical complication following aneurysmal subarachnoid hemorrhage (aSAH). It occurs in about 30% of patients surviving the initial hemorrhage, mostly between days 4 and 10 after aSAH. Clinical deterioration attributable to DCI is a diagnosis of exclusion and especially difficult to diagnose in patients who are comatose or sedated. The latter are typically patients with a high grade on the World Federation of Neurosurgical Societies scale (WFNS grade 4–5), who represent approximately 40–70% of the patient population with ruptured aneurysms. In this group of patients, the incidence of DCI is often underestimated and higher when compared to low WFNS grade patients. To overcome difficulties in diagnosing DCI, which is especially relevant in sedated and comatose patients, the article reports the most recent recommendation for definition of DCI and discusses their advantages and problematic issues in neurocritical care practice. Finally, appropriate neuromonitoring techniques and their clinical impact in high-grade SAH patients are summarized.

Multimodal brain monitoring in neurocritical care practice

Multimodal brain monitoring in neurocritical care practice

Authors’ Response to Letter Neurocritical Care Research Networks—Pediatric Considerations

We thank Drs. Bell et al. for their thoughtful comments regarding the contributions of pediatrics to the formation of specialized research networks to advance and promote clinical investigations in important critical care disorders affecting children. We acknowledge the outstanding efforts that the pediatric critical care community has undertaken and the significant salutary effects they have had on patients. The First Neurocritical Care Research Conference was the initial step of the Neurocritical Care Society (NCS) to begin to address objectives and goals for research endeavors in neurocritical care. One of the main goals of the conference was the creation of the Neurocritical Care Research Network (NCRN) and this conference was attended largely by NCS members, who are specialists in adult neurocritical care. The fact that no pediatric research networks were mentioned in the manuscripts reflects the composition of the conference attendees and our expertise toward adult neurocritical care practice rather than a deliberate omission on our part. The summary statements presented in the Journal reflect the material presented and discussed at the symposium. We admire the organized pediatric research infrastructure. In addition, we realize that NCRN is a recent effort and at a very early organizational stage but aspire to rise to a similar standard achieved by PECARN, PALISI, and PNCRG. As we acknowledge the comments of Bell et al. regarding the lack of pediatric research focus in the first Neurocritical Care Research Conference, we also like to indicate that the NCS is committed to pediatric patients with the formation of a pediatric neurocritical care committee and the initiatives to train and certify pediatricians in the field of neurocritical care. We agree with Bell et al. that investigators caring for adults and children can and should work together to address mutual goals and achieve them in a more efficient manner. In fact, we invite them to become active members of NCS and NCRN. This study was conducted on behalf of the First Neurocritical Care Research Conference Participants.

Neurocritical Care in Developing Countries

Neurocritical illness heavily burdens the developing world. In spite of a lack of resources for population-based health in most developing countries, there is an increasing demand for resource-intense strategies for acute neurological care. Factors including rising individual incomes in emerging economies, need for neurointensive care in humanitarian emergencies, growth of private hospitals, the rising burden of noncommunicable disease, and the practice of neurocritical care by specialists outside of neurology are discussed. Possible steps to improve the global practice of neurocritical care include: (1) emphasis on prevention of neurocritical illness through traffic safety and adequate outpatient treatment; (2) standardization of training requirements and skill sets; (3) guidelines on cost-effective measures including medications, equipment, and devices; (4) strengthening of surveillance systems and registries for both noncommunicable and communicable neurological diseases; (5) expanded use of teleneurology; (6) educational exchanges of neurointensive health care workers; and (7) monitoring of neurological intensive care unit death rates due to nosocomial infections, neurological disease, and other causes. A summary of reported mortality rates among neurocritically ill patients in African countries in recent years is provided as an illustrative example.

Dexmedetomidine for Neurological Surgery

Dexmedetomidine is a new intravenous drug gaining popularity in neuroanesthesia and neurocritical care practice. This alpha2-adrenergic receptor agonist offers a unique "cooperative sedation," anxiolysis, and analgesia with no respiratory depression. Cerebral effects are generally consistent with a desirable neurophysiological profile, including neuroprotective characteristics. In addition, sympatholytic and antinociceptive properties allow for hemodynamic stability at critical moments of neurosurgical stimulation. This review will address the neuropharmacology and neurophysiology of alpha2-adrenergic agonists and will specifically consider the rapidly evolving applicability of dexmedetomidine as an adjuvant to neurosurgical case management.