Effect of a neck collar on brain turgor: a potential role in preventing concussions?

BACKGROUND: Mild internal jugular vein (IJV) compression, aimed at increasing intracranial fluid volume to prevent motion of the brain relative to the skull, has reduced brain injury markers in athletes suffering repeated traumatic brain injuries. However, an increase in intracranial volume with IJV compression has not been well demonstrated. This study used transorbital ultrasound to identify changes in optic nerve sheath diameter (ONSD) as a direct marker of accompanying changes in intracranial volume. METHODS: Nineteen young, healthy adult volunteers (13 males and 6 females) underwent IJV compression of 20 cm H2O low in the neck, while in upright posture. IJV cross-sectional area at the level of the cricoid cartilage, and the change in right ONSD 3 mm behind the papillary segment of the optic nerve, were measured by ultrasound. Statistical analysis was performed using a paired t-test with Bonferroni correction. RESULTS: Mean (SD) cross-sectional area for the right IJV before and after IJV compression was 0.10 (0.05) cm2 and 0.57 (0.37) cm2, respectively (p=0.001). ONSD before and after IJV compression was 4.6 (0.5) mm and 4.9 (0.5) mm, respectively (p=0.001). CONCLUSIONS: These data verify increased cerebral volume following IJV compression, supporting the potential for reduced brain 'slosh' as a mechanism connecting IJV compression to possibly reducing traumatic brain injury following head trauma.

The role of routine cardiac investigations before hyperbaric oxygen treatment.

Cardiac complications are a rare but potentially serious consequence of hyperbaric oxygen treatment (HBOT), resulting from increased blood pressure and decreased heart rate and cardiac output associated with treatment. These physiologic changes are generally well-tolerated by patients without preexisting cardiac conditions, although those with known or undetected cardiac disease may be more vulnerable to treatment complications. Currently, there are no universally accepted guidelines for pre-HBOT cardiac screening to identify these patients at heightened risk, leading to variability in practice patterns. In the absence of HBOT-specific evidence, screening protocols might be adapted from the diving medicine community; however, given the important differences in physiological stressors, these may not be entirely applicable to patients undergoing HBOT. Traditional cardiac investigations such as electro- and echo-cardiograms are limited in their ability to detect relevant risk modifying states in the pre-HBOT patient, stymieing their cost-effectiveness as routine tests. In the absence of strong evidence to support routine cardiac investigation, we argue that a comprehensive history and physical exam - tailored to identify high-risk patients based on clinical parameters - may serve as a more practical screening tool. While certain unique patient groups such as those undergoing dialysis or with implanted cardiac devices may warrant specialised assessment, thorough evaluation may be sufficient to identify many patients unlikely to benefit from cardiac investigation in the pre-HBOT setting. A clinical decision-making tool based on suggested low-risk and high-risk features is offered to guide the use of targeted cardiac investigation prior to HBOT.

The role of hyperbaric oxygen therapy in the management of perioperative peripheral nerve injury: a scoping review of the literature.

BACKGROUND/IMPORTANCE: Peripheral nerve injury is an uncommon but potentially catastrophic complication of anesthesia and surgery, for which there are limited effective treatment options. Hyperbaric oxygen therapy is a unique medical intervention which improves tissue oxygen delivery and reduces ischemia via exposure to oxygen at supra-atmospheric partial pressures. While the application of hyperbaric oxygen therapy has been evidenced for other medical conditions involving relative tissue ischemia, its role in the management of peripheral nerve injury remains unclear. OBJECTIVE: This scoping review seeks to characterize rehabilitative outcomes when hyperbaric oxygen therapy is applied as an adjunct therapy in the treatment of perioperative peripheral nerve injury. EVIDENCE REVIEW: The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for scoping reviews, using a systematic screening and extraction process. The search included articles published from database inception until June 11, 2022, which reported clinical outcomes (in both human and non-human models) of peripheral nerve injury treated with hyperbaric oxygen therapy. FINDINGS: A total of 51 studies were included in the narrative synthesis. These consisted of animal (40) and human studies (11) treating peripheral nerve injury due to various physiological insults. Hyperbaric oxygen therapy protocols were highly heterogenous and applied at both early and late intervals relative to the time of peripheral nerve injury. Overall, hyperbaric oxygen therapy was reported as beneficial in 88% (45/51) of included studies (82% of human studies and 90% of animal studies), improving nerve regeneration and/or time to recovery with no reported major adverse events. CONCLUSIONS: Existing data suggest that hyperbaric oxygen therapy is a promising intervention in the management of perioperative peripheral nerve injury, in which tissue ischemia is the most common underlying mechanism of injury, neurological deficits are severe, and treatment options are sparse. This positive signal should be further investigated in prospective randomized clinical trials.

The Companion Curriculum: medical students' perceptions of the integration of humanities within medical education.

Background: The contributions of arts and humanities to medical education are known in the medical education community, but medical schools' offerings vary. The Companion Curriculum (CC) is a student-curated set of optional humanities content for medical students at the University of Toronto. This study evaluates integration of the CC to identify key enabling conditions for medical humanities engagement. Methods: A mixed-methods evaluation gauged usage and perceptions of integration of the CC among medical students using an online survey and focus groups. Narrative data underwent thematic analysis, supported by summary statistics of quantitative data. Results: Half of survey respondents were aware of the CC (n = 67/130; 52%), and, once prompted with a description, 14% had discussed it in their tutorial groups. Of students using the CC, 80% reported learning something new regarding their roles as communicators and health advocates. Themes were the perceived value of the humanities, internal student barriers, institutional neglect of the humanities, and student critiques and recommendations. Conclusion: Despite participants' interest in medical humanities, our CC remains underused. To improve humanities' visibility in the MD curriculum, our results indicate that greater institutional support, including faculty development and early curricular integration, is required. Further study should explore reasons for gaps between interest and participation.

Contexte: L'apport des arts et des sciences humaines à la formation médicale est bien connu du milieu de l'enseignement médical, mais l'offre des programmes à cet égard varie d'une faculté à l'autre. Le Companion curriculum (CC) est un recueil de contenu facultatif en sciences humaines, préparé par des étudiants et destiné aux étudiants en médecine de l'Université de Toronto. En évaluant l'intégration du CC au programme de formation, cette étude vise à dégager les principales conditions propices à un engagement en faveur des humanités médicales. Méthodes: Une évaluation à méthodes mixtes, à l'aide d'un sondage en ligne et de groupes de discussion, a permis de mesurer l'utilisation du CC par les étudiants en médecine et leur perception quant à l'intégration de cet outil. Les données narratives ont fait l'objet d'une analyse thématique, étayée par des statistiques sommaires de données quantitatives. Résultats: La moitié des répondants au sondage connaissaient le CC (n=67/130 ; 52%) et, une fois qu'on le leur a décrit, 14 % en avaient discuté dans leurs groupes de tutorat. Parmi les étudiants qui l'avaient utilisé, 80 % ont déclaré avoir appris quelque chose de nouveau concernant leurs rôles de communicateur et de promoteur de la santé. Les thèmes abordés étaient la valeur perçue des sciences humaines, les réserves des étudiants, le manque d'intérêt envers les sciences humaines au sein des établissements d'enseignement médical, ainsi que les critiques et les recommandations formulées par les étudiants. Conclusion: Malgré l'intérêt des participants pour les humanités médicales, notre CC demeure sous-utilisé. Nos résultats indiquent que le renforcement de la visibilité des sciences humaines dans le programme d'études médicales nécessite plus de soutien de la part des établissements, y compris par une formation des enseignants et par l'intégration des sciences humaines tôt dans le cursus du programme. Une étude plus approfondie permettrait d'explorer les raisons de l'écart entre l'intérêt et la participation.

The role of routine pulmonary imaging before hyperbaric oxygen treatment.

Respiratory injury during or following hyperbaric oxygen treatment (HBOT) is rare, but associated pressure changes can cause iatrogenic pulmonary barotrauma with potentially severe sequelae such as pneumothoraces. Pulmonary blebs, bullae, and other emphysematous airspace abnormalities increase the risk of respiratory complications and are prevalent in otherwise healthy adults. HBOT providers may elect to use chest X-ray routinely as a pre-treatment screening tool to identify these anomalies, particularly if a history of preceding pulmonary disease is identified, but this approach has a low sensitivity and frequently provides false negative results. Computed tomography scans offer greater sensitivity for airspace lesions, but given the high prevalence of incidental and insignificant pulmonary findings among healthy individuals, would lead to a high false positive rate because most lesions are unlikely to pose a hazard during HBOT. Post-mortem and imaging studies of airspace lesion prevalence show that a significant proportion of patients who undergo HBOT likely have pulmonary abnormalities such as blebs and bullae. Nevertheless, pulmonary barotrauma is rare, and occurs mainly in those with known underlying lung pathology. Consequently, routinely using chest X-ray or computed tomography scans as screening tools prior to HBOT for low-risk patients without a pertinent medical history or lack of clinical symptoms of cardiorespiratory disease is of low value. This review outlines published cases of patients experiencing pulmonary barotrauma while undergoing pressurised treatment/testing in a hyperbaric chamber and analyses the relationship between barotrauma and pulmonary findings on imaging prior to or following exposure. A checklist and clinical decision-making tool based on suggested low-risk and high-risk features are offered to guide the use of targeted baseline thoracic imaging prior to HBOT.

Innovations in suicide assessment and prevention during pandemics.

Emerging evidence, based on the synthesis of reports from past infectious disease-related public health emergencies, supports an association between previous pandemics and a heightened risk of suicide or suicide-related behaviours and outcomes. Anxiety associated with pandemic media reporting appears to be one critical contributing factor. Social isolation, loneliness, and the disconnect that can result from public health strategies during global pandemics also appear to increase suicide risk in vulnerable individuals. Innovative suicide risk assessment and prevention strategies are needed to recognise and adapt to the negative impacts of pandemics on population mental health.