Energy failure following traumatic brain injury: Potential mechanisms and impact of normobaric hyperoxia

Cerebral ischaemia is a frequent finding in post mortem studies following traumatic brain injury (TBI), but clinical studies using 15oxygen positron emission tomography (15O PET) suggest that classical ischaemia is uncommon beyond the first 24 hours after injury. Evidence of metabolic failure in the absence of classical ischaemia may represent ongoing neuronal dysfunction and progressive neuronal loss. Any therapeutic intervention that mitigates such metabolic derangements before they result in irreversible neuronal injury may improve tissue fate and improve the functional outcome for patients. Energy failure was spatially defined, characterised, and mapped using 15O and 18Fluoromisinidazole ([18F] FMISO) positron emission tomography. This enabled differentiation of classical ischaemia, diffusion hypoxia, and established infarction, and provided data on the dominant local mechanism at any given time after TBI. My thesis also aimed to examine the utility of diffusion tensor imaging and whole-brain proton MR spectroscopy (WB 1H MRS) as imaging biomarkers to investigate normobaric hyperoxia as a therapeutic option following traumatic brain injury (TBI). Using ([18F] FMISO PET evidence of tissue hypoxia consistent with microvascular ischaemia was found across the injured brain. The impact of normobaric hyperoxia (NBH) was examined in a clinical TBI cohort using diffusion tensor imaging and WB 1H MRS. Some evidence of benefit was found within the perilesional brain, but further studies should examine the value of a longer period of exposure to NBH and whether this has implications for functional outcome.AAGBI, MRC, Wellcome trus

A case of lactic acidosis complicating assessment and management of asthma.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.INTRODUCTION: Lactic acidosis often occurs in severely unwell patients presenting to Accident and Emergency. It is commonly associated with either hypoxia or decreased tissue perfusion secondary due to cardiovascular collapse or sepsis. CASE PRESENTATION: We present a case of severe lactic acidosis in the presence of normal tissue perfusion and oxygenation in a 31-year-old patient with poorly-controlled asthma. Acidosis promptly reversed on discontinuation of inhaled beta-agonists. CONCLUSION: Lactic acidosis secondary to inhaled beta-agonist administration may be a common scenario which can be misinterpreted very easily and can confuse the clinical picture. Further studies will be needed to establish the exact aetiology of this lactic acid production

An unusual complication following radiological percutaneous gastrostomy

<p>Abstract</p> <p>Introduction</p> <p>Intestinal malrotation is a condition, which is predominantly recognised in childhood. Because of the relative rarity, there is a possibility that it can be missed in the routine clinical care of adults. This case highlights the need for a high index of suspicion for malrotation when things go wrong in routine procedures. This can be the reason for catastrophic sepsis in patients who undergo minimally invasive procedures.</p> <p>Case presentation</p> <p>We present a patient with a malignant lesion of the tongue who went for elective placement of feeding tube who suffered unexpected complication as a result of malrotated large bowel.</p> <p>Conclusion</p> <p>Malrotation of the intestine can make a relatively straightforward procedure fraught with complications. Clinicians should have a high index of suspicion about malrotation when performing procedures like percutaneous gastrostomy and radiologically guided entrostomy. If there is an index of suspicion they should be screened prior to the procedure.</p

Is It Time to Beta Block the Septic Patient?

Beta blockers are some of the most studied drugs in the pharmacopoeia. They are already widely used in medicine for treating hypertension, chronic heart failure, tachyarrhythmias, and tremor. Whilst their use in the immediate perioperative patient has been questioned, the use of esmolol in the patients with established septic shock has been recently reported to have favourable outcomes. In this paper, we review the role of the adrenergic system in sepsis and the evidence for the use of beta stimulation and beta blockers from animal models to critically ill patients

Molecular mechanisms of traumatic brain injury: the missing link in management.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Head injury is common, sometimes requires intensive care unit admission, and is associated with significant mortality and morbidity. A gap still remains in the understanding of the molecular mechanism of this condition. This review is aimed at providing a general overview of the molecular mechanisms involved in traumatic brain injury to a busy clinician. It will encompass the pathophysiology in traumatic brain injury including apoptosis, the role of molecules and genes, and a brief mention of possible pharmacological therapies

Is It Time to Beta Block the Septic Patient?

Beta blockers are some of the most studied drugs in the pharmacopoeia. They are already widely used in medicine for treating hypertension, chronic heart failure, tachyarrhythmias, and tremor. Whilst their use in the immediate perioperative patient has been questioned, the use of esmolol in the patients with established septic shock has been recently reported to have favourable outcomes. In this paper, we review the role of the adrenergic system in sepsis and the evidence for the use of beta stimulation and beta blockers from animal models to critically ill patients.Peer Reviewe

Perioperative care of a patient with stroke.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Strokes and TIAs, with their high cumulative mortality and morbidity rates, are occurring with increasing frequency in western population 14. As such, it is vital for clinicians to provide optimal medical management in the perioperative period for those patients with this common neurological problem. This review aims to highlight the importance of the perioperative period and the stages of pre-optimization that can be taken by the multi-disciplinary team to aid this 171819. The evidence suggests that there are significant physiological advantages to early invasive monitoring and high dependency care in these complex patients. These cohort of patients are at increased risk of development of respiratory, gastrointestinal, nutritional and electrolyte disturbances so a constant vigil should be exercised in early recognition and treatment

Diagnosis and management of subarachnoid haemorrhage

Aneurysmal subarachnoid haemorrhage (aSAH) presents a challenge to clinicians because of its multisystem effects. Advancements in computed tomography (CT), endovascular treatments, and neurocritical care have contributed to declining mortality rates. The critical care of aSAH prioritises cerebral perfusion, early aneurysm securement, and the prevention of secondary brain injury and systemic complications. Early interventions to mitigate cardiopulmonary complications, dyselectrolytemia and treatment of culprit aneurysm require a multidisciplinary approach. Standardised neurological assessments, transcranial doppler (TCD), and advanced imaging, along with hypertensive and invasive therapies, are vital in reducing delayed cerebral ischemia and poor outcomes. Health care disparities, particularly in the resource allocation for SAH treatment, affect outcomes significantly, with telemedicine and novel technologies proposed to address this health inequalities. This article underscores the necessity for comprehensive multidisciplinary care and the urgent need for large-scale studies to validate standardised treatment protocols for improved SAH outcomes

Optical coherence tomography angiography analysis methods:a systematic review and meta-analysis

Optical coherence tomography angiography (OCTA) is widely used for non-invasive retinal vascular imaging, but the OCTA methods used to assess retinal perfusion vary. We evaluated the different methods used to assess retinal perfusion between OCTA studies. MEDLINE and Embase were searched from 2014 to August 2021. We included prospective studies including ≥ 50 participants using OCTA to assess retinal perfusion in either global retinal or systemic disorders. Risk of bias was assessed using the National Institute of Health quality assessment tool for observational cohort and cross-sectional studies. Heterogeneity of data was assessed by Q statistics, Chi-square test, and I2 index. Of the 5974 studies identified, 191 studies were included in this evaluation. The selected studies employed seven OCTA devices, six macula volume dimensions, four macula subregions, nine perfusion analyses, and five vessel layer definitions, totalling 197 distinct methods of assessing macula perfusion and over 7000 possible combinations. Meta-analysis was performed on 88 studies reporting vessel density and foveal avascular zone area, showing lower retinal perfusion in patients with diabetes mellitus than in healthy controls, but with high heterogeneity. Heterogeneity was lowest and reported vascular effects strongest in superficial capillary plexus assessments. Systematic review of OCTA studies revealed massive heterogeneity in the methods employed to assess retinal perfusion, supporting calls for standardisation of methodology