Connor Brenna

• MD
• Resident at University of Toronto

There exists in academic medicine a core ethical issue that is seldom pursued: trainees are frequently not the best person in the operating room at a given intervention being performed, and yet as a profession we understand a fundamental need to afford them opportunities to perform. Academic centres are traditionally associated with a higher qualit...

Background: Infectious disease-related public health emergencies (epidemics) may increase suicide risk, and high-quality evidence is needed to guide an international response. Aims: We investigated the potential impacts of epidemics on suicide-related outcomes. Method: We searched MEDLINE, EMBASE, PsycInfo, CINAHL, Scopus, Web of Science, PsyArXiv,...

Over the last four millennia, the discipline of anatomy and its relationships with medicine and society have evolved dramatically. Human dissection, the perennial tool for anatomical discovery and education, has both guided this evolution and matured alongside it. Soon after the first cadaveric dissections recorded in ancient Greece, China, India,...

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 s...

During the last 100 years, the role of anesthesiologists in psychiatry has focused primarily on facilitating electroconvulsive therapy and mitigating postoperative delirium and other perioperative neurocognitive disorders. The discovery of the rapid and sustained antidepressant properties of ketamine, and early results suggesting that other general...

Background As future health care leaders who work and train in diverse clinical settings, resident physicians are uniquely positioned to advance sustainable health care systems. However, residents are insufficiently educated about health care sustainability and given limited opportunities to engage in planetary health. Objective This article introd...

Background: Sickle cell disease is the most common human monogenetic disease, and its risks are amplified during pregnancy. Methods: This report describes a 35-year-old woman with HgbSS sickle cell disease who developed hyperhemolysis syndrome after undergoing an exchange transfusion during pregnancy. Results: In addition to conventional medical tr...

Background Despite the low-risk nature of participation in most clinical anesthesia trials, subject recruitment on the same day as surgery is often restricted due to the concerns of researchers and local research ethics boards that same-day consent may not afford adequate time and opportunity for patients to weigh and make decisions, as well as per...

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 know...

Introduction Transition-related surgery is an effective treatment for gender dysphoria, but the perioperative analgesic management of transgender patients is nuanced and potentially complicated by higher rates of mood and substance use disorders. Regional anesthetic techniques are known to reduce pain severity and opioid requirements; however, litt...

The administration of opioids can be followed by enduring neuroplastic changes in the peripheral and central nervous systems. This remodeling can lead to opioid-induced hyperalgesia, causing an increased sensitivity to painful stimuli. The description of opioid-induced changes in the somatosensory system has seldom been described in the setting of...

Background Hyperbaric oxygen therapy (HBOT) has several hemodynamic effects including increases in afterload (due to vasoconstriction) and decreases in cardiac output. This, along with rare reports of pulmonary edema during emergency treatment, has led providers to consider HBOT relatively contraindicated in patients with reduced left ventricular e...

During endochondral ossification, chondrocytes secrete a proteoglycan (PG)-rich extracellular matrix that can inhibit the process of cartilage maturation, including expression of Ihh and Col10a1. Because bone morphogenetic proteins (BMPs) can promote cartilage maturation, we hypothesized that cartilage PGs normally inhibit BMP signalling. According...

Background/importance Arachnoiditis is a rare but devastating disorder caused by various insults, one of which is purported to be local anesthetic neurotoxicity following neuraxial blockade. However, the relationship between local anesthetics administered into the neuraxis and the development of arachnoiditis has not been clearly elucidated. Objec...

Acute postoperative pain remains a critical treatment priority and has prompted a search for technologies and techniques to assist with intra‐operative analgesic monitoring and management. Anaesthetists traditionally rely on clinical judgement to guide intra‐operative analgesia, but several emerging technologies such as the nociception level index...

Background: Hyperbaric oxygen therapy (HBOT) has several hemodynamic effects including increases in afterload (due to vasoconstriction) and decreases in cardiac output. This, along with rare reports of pulmonary edema during emergency treatment, has led providers to consider HBOT relatively contraindicated in patients with reduced left ventricular...

Please confirm that an ethics committee approval has been applied for or granted Not relevant (see information at the bottom of this page) Application for ESRA Abstract Prizes I apply as a Trainee/Resident/Fellow (no age limit) Background and Aims Arachnoiditis is a rare but devastating disorder caused by a variety of insults, one purported to be...

Background and Aims Transition-related surgery (TRS) is an effective treatment for gender dysphoria, but the perioperative analgesic management of transgender patients may be complicated by higher rates of mood and substance use disorders. Regional anesthesia techniques reduce pain severity and opioid requirements, thereby improving postoperative r...

In many jurisdictions, legal frameworks afford patients the opportunity to make prospective medical decisions or to create directives that contain a special provision forfeiting their own ability to object to those decisions at a future time point, should they lose decision-making capacity. These agreements have been described with widely varying n...

Introduction: Phantom limb pain (PLP) refers to pain perceived in a part of the body removed by amputation or trauma. Despite the high prevalence of PLP following amputation and the significant morbidity associated with it, robust therapeutic approaches are currently lacking. Calcitonin, a polypeptide hormone, has recently emerged as a novel analg...

Hyperbaric oxygen therapy (HBOT) is known to be associated with pulmonary oxygen toxicity. However, the effect of modern HBOT protocols on pulmonary function is not completely understood. The present study evaluates pulmonary function test changes in patients undergoing serial HBOT. We prospectively collected data on patients undergoing HBOT from 2...

Background: Neurologic injury is relatively common in the context of spinal surgery, and is often treated with physiotherapy, pharmacotherapy, or surgical intervention. Emerging evidence supports a possible role for hyperbaric oxygen therapy (HBOT) in the treatment of peripheral and spinal nerve injuries. We describe the successful use of HBOT in...

Patients with implanted medical devices are increasingly referred for hyperbaric oxygen therapy (HBOT), and the safety of exposing some of these devices to hyperbaric environments has not previously been explored. There is a paucity of evidence surrounding the management of implanted neurological devices such as neurostimulators and intrathecal dru...

Chronic pain is a major source of morbidity for which there are limited effective treatments. Palmitoylethanolamide (PEA), a naturally occurring fatty acid amide, has demonstrated utility in the treatment of neuropathic and inflammatory pain. Emerging reports have supported a possible role for its use in the treatment of chronic pain, although this...

BACKGROUND A new class of interventions called digital therapeutics (DTx) is emerging and shows promise in the treatment of a spectrum of medical disorders and diseases. DTx are software-based interventions which could deliver unprecedented portability and scalability for patients. Their adoption and implementation were accelerated by the need for...

Background Digital therapeutics (DTx), a class of software-based clinical interventions, are promising new technologies that can potentially prevent, manage, or treat a spectrum of medical disorders and diseases as well as deliver unprecedented portability for patients and scalability for health care providers. Their adoption and implementation wer...

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) have emerged as an alternative to opioids for optimal postoperative pain management. However, the adoption of NSAIDs in sinonasal surgery has been impeded by a theoretical concern for postoperative bleeding. Our objective is to systematically review the efficacy and safety of NSAIDs for pat...

An archive, in the broadest sense, is any collection of historical materials. Archival research is a primary research methodology in which archival holdings constitute the key source of data. The technique is unique among qualitative research methodologies in that it traditionally requires physical exploration of one or more archives to acquire sou...

Objective While numerous recent guidelines support coronary computed tomography angiography (CTA) as a first-line test for stable chest pain, it remains underutilized by primary care physicians (PCPs). We aimed to evaluate cardiac investigation ordering practices following education sessions, as well as the total number of downstream tests and time...

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 p...

Background: Outpatients presenting with chest pain often face long wait times for cardiology consultation and subsequent investigation for obstructive coronary artery disease (CAD), during which adverse cardiovascular events may occur. Our objective was to describe the design of Cardiac Link, a coronary computed tomography angiogram (CCTA)-guided...

Background It remains controversial whether general anaesthetic drugs contribute to perioperative neurocognitive disorders in adult patients. Preclinical studies have generated conflicting results, likely because of differing animal models, study protocols, and measured outcomes. This scoping review of preclinical studies addressed the question: ‘D...

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...

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...

Background The expectation of pandemic-induced severe resource shortages has prompted authorities to draft and update frameworks to guide clinical decision-making and patient triage. While these documents differ in scope, they share a utilitarian focus on the maximization of benefit. This utilitarian view necessarily marginalizes certain groups, in...

Objective: The purpose of this review is to examine the effect of dexmedetomidine on delayed neurocognitive recovery (dNCR; cognitive dysfunction ≥1 week postoperative) after major noncardiac surgery. Background: Dexmedetomidine (DEX) effectively reduces delirium in the intensive care unit and reportedly attenuates cognitive decline following ma...

Analgesia and amnesia represent two complimentary pillars of anesthesia directed, respectively, at mitigating the experience of pain and the processes of encoding that experience into memory. These elements are typically combined in modern anesthetic techniques, but some circumstances exist – such as conscious sedation – in which the conditions of...

Objective : To examine the role of explainability in machine learning for healthcare (MLHC), and its necessity and significance with respect to effective and ethical MLHC application. Study Design and Setting : This commentary engages with the growing and dynamic corpus of literature on the use of MLHC and artificial intelligence (AI) in medicine,...

Unique reports of suicide and euthanasia date back more than 2 millennia, reflecting evolving philosophies of death and dying as expressions of the mores dominating a given era. One longstanding theme in the history of decisions to die has been staunch opposition founded in religious claims that one’s body is a trust from the divine (and therefore...

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 i...

Objective: The purpose of this systematic review and meta-analysis is to examine the effect of DEX on delayed dNCR (cognitive dysfunction ≥ 1 week postoperative) after cardiac surgery. Background: DEX has salutary effects on cognitive outcomes following cardiac surgery, however, studies are limited by inconsistent assessment tools, timing, and d...

Purpose of Review Perioperative neurocognitive disorders are common following surgery and have serious socioeconomic impacts. Despite this, these disorders remain under recognized and underdiagnosed. To facilitate detection and direct patients towards appropriate preventative interventions, assessment of cognition during the perioperative period is...

Objective: Mechanical endovascular thrombectomy (EVT) is an increasingly relied-on treatment for clot retrieval in the context of ischemic strokes, which otherwise are associated with significant morbidity and mortality. Despite several known risks associated with this procedure, there is a high degree of technical heterogeneity across both center...

Emerging technologies such as artificial intelligence are actively revolutionizing the healthcare industry. While there is widespread concern that these advances will displace human practitioners within the healthcare sector, there are several tasks – including original and nuanced ethical decision making – that they cannot replace. Further, the im...

Kenneth McKenzie arrived in Toronto in 1923, bringing with him the legacy of being the first neurosurgeon in Canada. Since then,Toronto has established itself as the hub of Canadian neurosurgery, in both volumes of cases, the strength of trainees, as well asresearch output (1). As one of the largest training programs in North America (2), Toronto h...

Preexisting cognitive impairment is an important, but underrecognized, predictor of postoperative neurocognitive dysfunction, a common and important sequela of surgery. We have applied computerized neuropsychological testing as an efficient and reliable means of detecting preexisting cognitive impairment in two studies of cardiac and noncardiac sur...

Animal model research is insufficient to guide the application of novel therapies in human patients, but the same objections should apply to human trials which do not representatively sample sexes in the population. Female participants have historically been excluded from anaesthesia research due to concerns of potential teratogenicity and unfounde...

Carotid-cavernous fistulas (CCFs) are abnormal connections between the carotid arterial system and the cavernous sinus. These acquired vascular malformations may result in severe orbital congestion and sight-threatening complications. The authors present their experience in gaining access to the superior ophthalmic vein to embolize indirect CCFs in...

The four-principle approach to medical ethics, balancing prima facie obligations to beneficence, nonmaleficence, autonomy, and justice, has supplied a common language for the application of ethical analysis to medical practice for the last four decades. The frayed edges of this edifice are made visible, however, by the ongoing COVID-19 pandemic (an...

Anatomical dissection is almost ubiquitous in modern medical education, masking a complex history of its practice. Dissection with the express purpose of understanding human anatomy began more than two millennia ago with Herophilus, but was soon after disavowed in the third century BCE. Historical evidence suggests that this position was based on c...

Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy of the adrenal cortex. This study characterizes a single-institution cohort of children treated for ACC, and explores the relationship between clinical outcomes of ACC and germline TP53 mutation status. We performed a retrospective chart review of 23 consecutive pediatric patients with...

Surgery and Medicine are broadly considered as the two fundamental paths that a physician's career can follow. But their convergence under the singular umbrella of doctoring is relatively recent in the context of medical history. Their co-existence within the structure of medical education and the healthcare system suggest that they bear great simi...

Background: Carotid-cavernous fistulas (CCFs) are abnormal communications between the arterial and venous circulation within the cavernous sinus, manifesting in myriad neurological and ophthalmological sequalae. In rare circumstances patients' unique vascular anatomies preclude standard endovascular treatment for this pathology, warranting combined...

Spinal hemangioblastomas represent unique operative challenges given their exquisite vascularity and rare incidence. Herein, we present a case of a 50-year-old gentleman with progressive cauda equina syndrome secondary to a lumbosacral sHGB. The lesion exhibited vascular shunting and dilation of veins tracking the entire spinal cord. We performed a...

Background: The number of unmatched Canadian Medical Graduates (CMGs) has risen dramatically over the last decade. To identify long-term solutions to this problem, an understanding of the factors contributing to these rising unmatched rates is critical. Methods: Using match and electives data from 2009-2019, we employed machine learning algorith...

Objective To compare different methods for investigation of stable, low-risk chest pain and identify the best first-line test for patients at low or intermediate risk of coronary artery disease (CAD). Sources of information The MEDLINE database was searched for articles on chest pain investigation from 1978 to 2019 using the following key terms: ch...