J. Gordon Boyd

Queen's University | QueensU · Department of Medicine and Critical Care Medicine

Background Transcatheter aortic valve implantation (TAVI) is a routine procedure that is often performed on older adults that are high-risk patients with severe aortic stenosis. Patients after TAVI may experience neurological complications. However, there is a lack of objective neurological testing available for patients undergoing cardiac surgery....

Background Neurocognitive impairment is a common finding across the spectrum of kidney disease and carries important consequences for quality of life. We previously demonstrated that robotic technology can identify neurocognitive impairments not readily detectable by traditional testing in patients with acute kidney injury (AKI) and chronic kidney...

Objective Carotid endarterectomy is recommended for the prevention of ischaemic stroke due to carotid stenosis. However, the risk of stroke after carotid endarterectomy has been estimated at 2% – 5%. Monitoring intra-operative cerebral oxygenation with near infrared spectroscopy (NIRS) has been assessed as a strategy to reduce intra- and post-opera...

Patients admitted to the intensive care unit with critical COVID-19 often require prolonged periods of mechanical ventilation. Difficulty weaning, lack of progress, and clinical deterioration are commonly encountered. These conditions should prompt a thorough evaluation for persistent or untreated manifestations of COVID-19, as well as complication...

Introduction Initiation of acute kidney replacement therapy (KRT) is common in critically ill adults admitted to the intensive care unit (ICU), and associated with increased morbidity and mortality. KRT has been linked to poor neurocognitive outcomes, leading to reduced quality of life and increased utilisation of healthcare resources. Adults on di...

Background Kinarm Standard Tests (KSTs) is a suite of upper limb tasks to assess sensory, motor, and cognitive functions, which produces granular performance data that reflect spatial and temporal aspects of behavior (>100 variables per individual). We have previously used principal component analysis (PCA) to reduce the dimensionality of multivari...

Background Patients on hemodialysis (HD) are known to exhibit low values of regional cerebral oxygenation (rSO2) and impaired cognitive functioning. The etiology of both is currently unknown. Objective To determine the feasibility of serially monitoring rSO2 in patients initiating HD. In addition, we sought to investigate how rSO2 is related to he...

Background: Acute kidney injury (AKI) is associated with long-term morbidity and mortality. The effects of AKI on neurocognitive functioning remain unknown. Our objective was to quantify neurocognitive impairment after an episode of AKI. Methods: Survivors of AKI were compared to age-matched controls, as well as a convenience sample of patients...

Background: Several studies have previously reported the presence of altered cerebral perfusion during sepsis. However, the role of non-invasive neuromonitoring, and the impact of altered cerebral perfusion, in sepsis patients with delirium remains unclear. Methods: We performed a systematic review of studies that used near-infrared spectroscopy (...

OBJECTIVES This systematic review aims to provide an up-to-date summary of the current literature examining the relationship between intraoperative regional cerebral oxygen saturation and neurological complications after cardiac surgery. METHODS Observational and interventional studies investigating the link between regional cerebral oxygen satura...

Background The minimum duration of pulselessness required before organ donation after circulatory determination of death has not been well studied. Methods We conducted a prospective observational study of the incidence and timing of resumption of cardiac electrical and pulsatile activity in adults who died after planned withdrawal of life-sustain...

Background Neurocognitive impairment is commonly reported in patients with chronic kidney disease (CKD). The precise nature of this impairment is unclear, due to the lack of objective and quantitative assessment tools used. The feasibility of using robotic technology to precisely quantify neurocognitive impairment in patients with CKD is unknown.Me...

Rationale: Understanding the magnitude of moral distress and its associations may point to solutions. Objective: To understand the magnitude of moral distress and other measures of wellness in Canadian critical care physicians, to determine any associations among these measures, and to identify potentially modifiable factors. Methods: This was...

Objectives: We provide preliminary multicenter data to suggest that recruitment and collection of physiologic data necessary to quantify cerebral autoregulation and individualized blood pressure targets are feasible in postcardiac arrest patients. We evaluated the feasibility of a multicenter protocol to enroll patients across centers, as well as...

Introduction: Immunological dysfunction is common in critically ill patients but its clinical significance and the optimal method to measure it are unknown. The level of tumor necrosis factor alpha (TNF-α) after ex-vivo whole blood stimulation with lipopolysaccharide (LPS) has been proposed as a possible method to quantify immunological function....

Rationale: Studies suggest that reduced cerebral perfusion may contribute to delirium development in the intensive care unit (ICU). However, evidence is limited due to factors including small sample size and limited inclusion of covariates. Objectives: To assess the feasibility of a multicentre prospective observational study using a multi-modal...

PurposeCanadian donor management practices have not been reported. Our aim was to inform clinicians and other stakeholders about the range of current practices.Methods This prospective observational cohort study enrolled consecutive, newly consented organ donors from August 1 2015 to July 31 2018 at 27 academic and five community adult intensive ca...

Introduction: Immunological dysfunction is common in critically ill patients but its clinical significance and the optimal method to measure it are unknown. The level of tumor necrosis factor alpha (TNF-α) after ex-vivo whole blood stimulation with lipopolysaccharide (LPS) has been proposed as a possible method to quantify immunological function. W...

Introduction: Immunological dysfunction is common in critically ill patients but its clinical significance and the optimal method to measure it are unknown. The level of tumor necrosis factor alpha (TNF-α) after ex-vivo whole blood stimulation with lipopolysaccharide (LPS) has been proposed as a possible method to quantify immunological function. W...

Aims Patients undergoing coronary artery bypass grafting (CABG) surgery may experience neurological impairment. We examined whether intraoperative regional cerebral oxygen saturation (rSO2) and neurological dysfunction prior to surgery, measured by robotic technology, are important predictors of post-operative performance following CABG surgery. M...

Background: To maintain adequate oxygen delivery to tissue, resuscitation of critically ill patients is guided by assessing surrogate markers of perfusion. As there is no direct indicator of cerebral perfusion used in routine critical care, identifying an accurate strategy to monitor brain perfusion is paramount. Near-infrared spectroscopy (NIRS)...

Introduction Patients undergoing cardiac surgery may experience both short-term and long-term postoperative neurological problems. However, the underlying cause of this impairment is unclear. Regional cerebral oxygen saturation (rSO 2 ) levels may play a role in the development of acute dysfunction, known as postoperative delirium, in addition to l...

Introduction Survivors of critical illness frequently exhibit acute and chronic neurological complications. The underlying aetiology of this dysfunction remains unknown but may be associated with cerebral ischaemia. This study will use near-infrared spectroscopy to non-invasively quantify regional cerebral oxygenation (rSO 2 ) to assess the associa...

Background A common neurological complication of critical illness is delirium, defined as an acute change in level of consciousness, with impaired attention and disorganized thinking. Patients with delirium have increased risk of long-term cognitive dysfunction and mortality. The cause is unknown, which limits our ability to design therapeutic inte...

Delirium is common during critical illness and is associated with morbidity and mortality, but its pathophysiology is unknown. We tested whether dysfunctional cerebral autoregulation (CA) contributes to the development of delirium. Adult patients (n = 40) with respiratory failure and/or shock were prospectively enrolled. Continuous recordings of re...

Purpose: To assess the feasibility of using an integrated multimodal data collection strategy to characterize the post-intensive care syndrome (PICS). Materials and methods: Adult patients admitted to the ICU requiring invasive mechanical ventilation for >24 h and/or requiring vasopressor support were eligible for enrollment. We assessed cogniti...

Importance Cognitive dysfunction is reportedly highly prevalent among chronic kidney disease (CKD) patients. A variety of screening tools and neuropsychiatric batteries are utilized to quantify the magnitude and nature of this dysfunction in CKD patients. Objective To summarize the neurocognitive testing used and determine what degree cognitive dy...

Background: The KINARM robot produces a granular dataset of participant performance metrics associated with proprioceptive, motor, visuospatial, and executive function. This comprehensive battery includes several behavioral tasks that each generate 9 to 20 metrics of performance. Therefore, the entire battery of tasks generates well over 100 metri...

Objective: To obtain preliminary evidence for the efficacy of lactoferrin as a preventative measure for nosocomial infections and inform the conduct of a definitive study. Design: Phase 2, multicenter, randomized, double-blind, placebo-controlled study. Setting: Medical-surgical ICUs. Patients: Adult, critically ill patients receiving invasi...

Background: It is well-known that patients undergoing coronary artery bypass grafting (CABG) surgery may experience neurological dysfunction following their operation. However, the nature of this dysfunction has not been properly quantified. Furthermore, the relationship between post-operative impairment and cerebral oxygen saturation during surge...

Background Wearable devices generate signals detecting activity, sleep, and heart rate, all of which could enable detailed and near-continuous characterization of recovery following critical illness. Methods To determine the feasibility of using a wrist-worn personal fitness tracker among patients recovering from critical illness, we conducted a p...

Introduction Frailty is associated with reduced functional capacity, decreased resistance to stressors and is predictive of a range of adverse health outcomes, including dependency, hospitalisation and mortality. Early identification of frailty may prevent, reduce and postpone adverse health outcomes. However, there is a need for additional evidenc...

Objectives: To reduce medication turnaround times during neurological emergencies, a multidisciplinary team developed a neurological emergency crash trolley in our intensive care unit. This trolley includes phenytoin, hypertonic saline and mannitol, as well as other equipment. The aim of this study was to assess whether the cart reduced turnaround...

Purpose: Functional status and chronic health status are important baseline characteristics of critically ill patients. The assessment of frailty on admission to the intensive care unit (ICU) may provide objective, prognostic information on baseline health. To determine the impact of frailty on the outcome of critically ill patients, we performed...

Purpose To test the hypothesis that poor brain tissue oxygenation (BtO2) during the first 24 h of critical illness correlates with the proportion of time spent delirious. We also sought to define the physiological determinants of BtO2. Materials and methods Adult patients admitted to the ICU within the previous 24 h were considered eligible for en...

Background: Serum biomarkers may play a role in prognostication after cardiac arrest. This study was designed to assess the feasibility of using two-dimensional gel electrophoresis (2D-GE) coupled with mass spectrometry (MS) as a proteomic strategy to identify novel biomarkers that may predict neurological recovery. Methods: Adult comatose survi...

Purpose: We have previously shown that electroencephalography (EEG) may be an underutilized monitoring modality in a single general medical-surgical ICU, that does not have a specific neurocritical care consultation service or neurocritical care unit. The present study was designed to describe the pattern of EEG utilization across 3 academic ICUs...

Background: As the sensing capabilities of wearable devices improve, there is increasing interest in their application in medical settings. Capabilities such as heart rate monitoring may be useful in hospitalized patients as a means of enhancing routine monitoring or as part of an early warning system to detect clinical deterioration. Objective:...

p class="abstract"> Background: Acute and chronic neurological complications amongst survivors of critical illness is common, however, the underlying etiology of this neurological dysfunction is unknown. This is the first study to use near-infrared spectroscopy to non-invasively measure brain tissue oxygenation, as a surrogate marker of cerebral pe...

The cause of ICU delirium is unknown. We used near infrared spectroscopy (NIRS) to measure brain tissue oxygenation (BtO2) in critically ill patients, to test the hypothesis that poor cerebral oxygen delivery contributes to ICU delirium. Methods: Adult patients were enrolled if they required mechanical ventilation for >24 hours, and/or vasoactive a...

Cognitive impairment is highly prevalent in individuals with end stage kidney disease (ESKD) undergoing hemodialysis. The cause is not understood. Our overall hypothesis is that repetitive cerebral hypoperfusion during hemodialysis contributes to accelerated cognitive dysfunction in this patient population. Methods: All participants underwent a bas...

A 37-year-old man presented with a 7-month history of vertigo, nausea, dysphagia, right-sided tinnitus, and hearing loss. He denied headache, paresthesias, change in vision, or problems with cognition. He endorsed a history of progressive fatigue, generalized weakness, and poor libido. His symptoms left him functionally impaired and bedridden.

Long-term cognitive dysfunction is common among survivors of critical illness. The etiology of this cognitive dysfunction is unknown, but it may relate to cerebral hypoxemia and hypoperfusion. Near infrared spectroscopy (NIRS) has been used to measure brain tissue oxygenation(BtO2) in patients during cardiac surgery and after cardiac arrest. Prelim...

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Delirium is common in critically ill patients and its presence is associated with increased mortality and increased likelihood of poor cognitive function among survivors. However, the cause of delirium is unknown. The purpose of this study was to demonstrate the feasibility of using near-infrared spectroscopy (NIRS) to assess brain tissue oxygenati...

Background: Patients undergoing neurosurgery are at risk of cerebral ischaemia with resultant cerebral hypoxia and neuronal cell death. This can increase both the risk of mortality and long term neurological disability. Induced hypothermia has been shown to reduce the risk of cerebral ischaemic damage in both animal studies and in humans who have...