Higher intracranial pressure variability is associated with lower cerebrovascular resistance in aneurysmal subarachnoid hemorrhage.

Higher intracranial pressure variability (ICPV) has been associated with a more favorable cerebral energy metabolism, lower rate of delayed ischemic neurologic deficits, and more favorable outcome in aneurysmal subarachnoid hemorrhage (aSAH). We have hypothesized that higher ICPV partly reflects more compliant and active cerebral vessels. In this study, the aim was to further test this by investigating if higher ICPV was associated with lower cerebrovascular resistance (CVR) and higher cerebral blood flow (CBF) after aSAH.

Cerebral Microdialysis Monitoring of Energy Metabolism: Relation to Cerebral Blood Flow and Oxygen Delivery in Aneurysmal Subarachnoid Hemorrhage.

Introduction: In this study, we investigated the roles of cerebral blood flow (CBF) and cerebral oxygen delivery (CDO 2 ) in relation to cerebral energy metabolism after aneurysmal subarachnoid hemorrhage (aSAH).

Methods: Fifty-seven adult aSAH patients treated on the neurointensive care unit at Uppsala, Sweden between 2012 and 2020, with at least 1 xenon-enhanced computed tomography (Xe-CT) scan in the first 14 days after ictus and concurrent microdialysis (MD) monitoring, were included in this retrospective study. CBF was measured globally and focally (around the MD catheter) with Xe-CT, and CDO 2 calculated.

Cerebral Blood Flow and Oxygen Delivery in Aneurysmal Subarachnoid Hemorrhage: Relation to Neurointensive Care Targets.

Background: The primary aim was to determine to what extent continuously monitored neurointensive care unit (neuro-ICU) targets predict cerebral blood flow (CBF) and delivery of oxygen (CDO) after aneurysmal subarachnoid hemorrhage. The secondary aim was to determine whether CBF and CDO were associated with clinical outcome.

Methods: In this observational study, patients with aneurysmal subarachnoid hemorrhage treated at the neuro-ICU in Uppsala, Sweden, from 2012 to 2020 with at least one xenon-enhanced computed tomography (Xe-CT) obtained within the first 14 days post ictus were included.

Arterial lactate in traumatic brain injury - Relation to intracranial pressure dynamics, cerebral energy metabolism and clinical outcome.

Purpose: High arterial lactate is associated with disturbed systemic physiology. Lactate can also be used as alternative cerebral fuel and it is involved in regulating cerebral blood flow. This study explored the relation of endogenous arterial lactate to systemic physiology, pressure autoregulation, cerebral energy metabolism, and clinical outcome in traumatic brain injury (TBI).

Arterial Oxygenation in Traumatic Brain Injury-Relation to Cerebral Energy Metabolism, Autoregulation, and Clinical Outcome.

Background: Ischemic and hypoxic secondary brain insults are common and detrimental in traumatic brain injury (TBI). Treatment aims to maintain an adequate cerebral blood flow with sufficient arterial oxygen content. It has been suggested that arterial hyperoxia may be beneficial to the injured brain to compensate for cerebral ischemia, overcome diffusion barriers, and improve mitochondrial function.

Systemic Hyperthermia in Traumatic Brain Injury-Relation to Intracranial Pressure Dynamics, Cerebral Energy Metabolism, and Clinical Outcome.

Background: Systemic hyperthermia is common after traumatic brain injury (TBI) and may induce secondary brain injury, although the pathophysiology is not fully understood. In this study, our aim was to determine the incidence and temporal course of hyperthermia after TBI and its relation to intracranial pressure dynamics, cerebral metabolism, and clinical outcomes.

Materials And Methods: This retrospective study included 115 TBI patients.

CBF changes and cerebral energy metabolism during hypervolemia, hemodilution, and hypertension therapy in patients with poor-grade subarachnoid hemorrhage.

Objective: Despite the multifactorial pathogenesis of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH), augmentation of cerebral blood flow (CBF) is still considered essential in the clinical management of DCI. The aim of this prospective observational study was to investigate cerebral metabolic changes in relation to CBF during therapeutic hypervolemia, hemodilution, and hypertension (HHH) therapy in poor-grade SAH patients with DCI.

Methods: CBF was assessed by bedside xenon-enhanced CT at days 0-3, 4-7, and 8-12, and the cerebral metabolic state by cerebral microdialysis (CMD), analyzing glucose, lactate, pyruvate, and glutamate hourly.

Mild Hyperventilation in Traumatic Brain Injury-Relation to Cerebral Energy Metabolism, Pressure Autoregulation, and Clinical Outcome.

Objective: Hyperventilation is a controversial treatment in traumatic brain injury (TBI). Prophylactic severe hyperventilation (below 3.3 kPa/25 mm Hg) is generally avoided, due to the risk of cerebral ischemia.

Temporal Dynamics of Cerebral Blood Flow During the Acute Course of Severe Subarachnoid Hemorrhage Studied by Bedside Xenon-Enhanced CT.

Background: Compromised cerebral blood flow (CBF) is a crucial factor in delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Repeated measurement of CBF may improve our understanding of the temporal dynamics following SAH. The aim of this study was to assess CBF at different phases of the acute course in poor-grade SAH patients, hypothesizing more pronounced disturbances at day 4-7, and that the initial level of CBF determines the following course of CBF.

Effect of HHH-Therapy on Regional CBF after Severe Subarachnoid Hemorrhage Studied by Bedside Xenon-Enhanced CT.

Background: Management of delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH) is difficult and still carries controversies. In this study, the effect of therapeutic hypervolemia, hemodilution, and hypertension (HHH-therapy) on cerebral blood flow (CBF) was assessed by xenon-enhanced computerized tomography (XeCT) hypothesizing an increase in CBF in poorly perfused regions.

Methods: Bedside XeCT measurements of regional CBF in mechanically ventilated SAH patients were routinely scheduled for day 0-3, 4-7, and 8-12.

The Correlation between Cerebral Blood Flow Measured by Bedside Xenon-CT and Brain Chemistry Monitored by Microdialysis in the Acute Phase following Subarachnoid Hemorrhage.

Cerebral microdialysis (MD) may be used in patients suffering from subarachnoid hemorrhage (SAH) to detect focal cerebral ischemia. The cerebral MD catheter is usually placed in the right frontal lobe and monitors the area surrounding the catheter. This generates the concern that a fall in cerebral blood flow (CBF) and ischemic events distant to the catheter may not be detected.

Early low cerebral blood flow and high cerebral lactate: prediction of delayed cerebral ischemia in subarachnoid hemorrhage.

OBJECTIVE Delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH) is one of the major contributors to poor outcome. It is crucial to be able to detect early signs of DCI to prevent its occurrence. The objective of this study was to determine if low cerebral blood flow (CBF) measurements and pathological microdialysis parameters measured at the bedside can be observed early in patients with SAH who later developed DCI.

An evaluation of the mixed pediatric unit for blood loss replacement in pediatric craniofacial surgery.

Background: Surgical correction for craniosynostosis is often associated with significant perioperative hemorrhage. We implemented a transfusion strategy with a strict protocol including transfusion triggers, frequent assessment of coagulation tests, and the use of a novel transfusion unit, the mixed pediatric unit.

Aim: The aim of the study was to evaluate if the applied transfusion strategy could reduce total blood loss and number of blood donors.

Increased risk of critical CBF levels in SAH patients with actual CPP below calculated optimal CPP.

Background: Cerebral pressure autoregulation can be quantified with the pressure reactivity index (PRx), based on the correlation between blood pressure and intracranial pressure. Using PRx optimal cerebral perfusion pressure (CPPopt) can be calculated, i.e.

Hemodynamic Disturbances in the Early Phase After Subarachnoid Hemorrhage: Regional Cerebral Blood Flow Studied by Bedside Xenon-enhanced CT.

Background: The mechanisms leading to neurological deterioration and the devastating course of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) are still not well understood. Bedside xenon-enhanced computerized tomography (XeCT) enables measurements of regional cerebral blood flow (rCBF) during neurosurgical intensive care. In the present study, CBF characteristics in the early phase after severe SAH were explored and related to clinical characteristics and early clinical course outcome.

Bedside Xenon-CT Shows Lower CBF in SAH Patients with Impaired CBF Pressure Autoregulation as Defined by Pressure Reactivity Index (PRx).

Background: Subarachnoid hemorrhage (SAH) is a disease with a high rate of unfavorable outcome, often related to delayed cerebral ischemia (DCI), i.e., ischemic injury that develops days-weeks after onset, with a multifactorial etiology.

Imaging of cerebral blood flow in patients with severe traumatic brain injury in the neurointensive care.

Ischemia is a common and deleterious secondary injury following traumatic brain injury (TBI). A great challenge for the treatment of TBI patients in the neurointensive care unit (NICU) is to detect early signs of ischemia in order to prevent further advancement and deterioration of the brain tissue. Today, several imaging techniques are available to monitor cerebral blood flow (CBF) in the injured brain such as positron emission tomography (PET), single-photon emission computed tomography, xenon computed tomography (Xenon-CT), perfusion-weighted magnetic resonance imaging (MRI), and CT perfusion scan.

Monitoring of Cerebral Blood Flow and Metabolism Bedside in Patients with Subarachnoid Hemorrhage - A Xenon-CT and Microdialysis Study.

Cerebral ischemia is the leading cause of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Although 70% of the patients show angiographic vasospasm only 30% develop symptomatic vasospasm defined as delayed cerebral ischemia (DCI). Early detection and management of reversible ischemia is of critical importance in patients with SAH.

The neurological wake-up test does not alter cerebral energy metabolism and oxygenation in patients with severe traumatic brain injury.

Background: The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen saturation (SjvO2), and/or arterial-venous difference (AVD) for glucose, lactate, and oxygen in patients with severe TBI.

Mechanisms underlying ICU muscle wasting and effects of passive mechanical loading.

Introduction: Critically ill ICU patients commonly develop severe muscle wasting and impaired muscle function, leading to delayed recovery, with subsequent increased morbidity and financial costs, and decreased quality of life for survivors. Critical illness myopathy (CIM) is a frequently observed neuromuscular disorder in ICU patients. Sepsis, systemic corticosteroid hormone treatment and post-synaptic neuromuscular blockade have been forwarded as the dominating triggering factors.

Identification of incident injuries in hospital discharge registers.

Background: Hospital discharge data on injuries constitute a potentially powerful data source for epidemiologic studies. However, reliable identification of incident injury admissions is necessary. The objective of this study was to develop a prediction model for identifying incident hospital admissions, based on variables derived from a hospital discharge register.