Search

Dexmedetomidine is a selective alpha-2 adrenergic agonist utilized for sedation in critically ill patients. 1 We present the case of a morbidly obese critically ill patient who experienced profound hyperthermia, with a maximum temperature of 41.4°C, hours after starting a dexmedetomidine infusion that was otherwise not explained by her clinical diagnoses. The hyperthermia resolved hours following cessation of the infusion. Dexmedetomidine was assessed as probable in terms of causing this adverse effect. Dexmedetomidine may be associated not only with low-grade fever, but as demonstrated in our case, it may be associated with significant temperature elevations requiring cessation of therapy to restore normothermia.

Objective: To evaluate whether introduction of CCRTs reduced mortality rates among patients who developed a postoperative complication, also referred to as FTR., Background: CCRTs were introduced to improve patients' postoperative outcomes. Its effect on FTR continues to be actively investigated., Methods: We conducted a population-based retrospective cohort study using administrative data from Ontario, Canada. We identified 810,279 patients admitted to hospital for major surgical procedures between January 2004 and December 2014, with a washout period consisting of the 9 months before and after the implementation of CCRTs in January 2007. Difference-in-differences analysis among patients who developed a postoperative complication (n = 148,882) was used to estimate the association between CCRT implementation and FTR before and after CCRT implementation in hospitals that did - versus did not - implement CCRT during the study period., Results: A total of 810,279 patients were included, of whom 148,882 (18.4%) developed a postoperative surgical complication. Among patients who developed a postoperative complication, the overall proportion of FTR was 9.2% (n = 13,659). Among patients in hospitals that introduced CCRT, the RR of FTR was 0.84, [95% confidence interval (CI) 0.78-0.90] after implementation of CCRT, while over the same time period, the RR was 0.85 (95% CI 0.80-0.91) in hospitals that did not implement CCRT. The RR ratio (difference-indifferences) was 0.99 (95% CI 0.89-1.09). Among patients undergoing orthopedic surgery, the RR ratio was 0.84 (95% CI 0.75-0.95)., Conclusion: Although implementation of CCRTs in hospitals in Ontario, Canada, did not reduce FTR among all surgical patients having surgery, CCRTs may reduce the risk of FTR among patients having orthopedic surgery., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Viscoelastic properties of articular cartilage have been characterised at physiological frequencies. However, studies investigating the interaction between cartilage and subchondral bone and the influence of underlying bone histomorphometry on the viscoelasticity of cartilage are lacking., Method: Dynamic Mechanical Analysis (DMA) has been used to quantify the dynamic viscoelasticity of bovine tibial plateau osteochondral cores, over a frequency sweep from 1 to 88 Hz. Specimens (approximately aged between 18 and 30 months) were neither osteoarthritic nor otherwise compromised. A maximum nominal stress of 1.7 MPa was induced. Viscoelastic properties of cores have been compared with that of its components (cartilage and bone) in terms of the elastic and viscous components of both structural stiffness and material modulus. Micro-computed tomography scans were used to quantify the histomorphological properties of the subchondral bone., Results: Opposing frequency-dependent loss stiffness, and modulus, trends were witnessed for osteochondral tissues: for cartilage it increased logarithmically (P < 0.05); for bone it decreased logarithmically (P < 0.05). The storage stiffness of osteochondral cores was logarithmically frequency-dependent (P < 0.05), however, the loss stiffness was typically frequency-independent (P > 0.05). A linear relationship between the subchondral bone plate (SBP) thickness and cartilage thickness (P < 0.001) was identified. Cartilage loss modulus was linearly correlated to bone mineral density (BMD) (P < 0.05) and bone volume (P < 0.05)., Conclusion: The relationship between the subchondral bone histomorphometry and cartilage viscoelasticity (namely loss modulus) and thickness, have implications for the initiation and progression of osteoarthritis (OA) through an altered ability of cartilage to dissipate energy., (Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Cracks can occur in the articular cartilage surface due to the mechanical loading of the synovial joint, trauma or wear and tear. However, the propagation of such cracks under different frequencies of loading is unknown. The objective of this study was to determine the effect of frequency of loading on the growth of a pre-existing crack in cartilage specimens subjected to cyclic tensile strain. A 2.26mm crack was introduced into cartilage specimens and crack growth was achieved by applying a sinusoidally varying tensile strain at frequencies of 1, 10 and 100Hz (i.e. corresponding to normal, above normal and up to rapid heel-strike rise times, respectively). These frequencies were applied with a strain of between 10-20% and the crack length was measured at 0, 20, 50, 100, 500, 1000, 5000 and 10,000 cycles of strain. Crack growth increased with increasing number of cycles. The maximum crack growth was 0.6 ± 0.3 (mean ± standard deviation), 0.8 ± 0.2 and 1.1 ± 0.4mm at frequencies of 1, 10 and 100Hz, respectively following 10,000 cycles. Mean crack growth were 0.3 ± 0.2 and 0.4 ± 0.2 at frequencies of 1 and 10Hz, respectively. However, this value increased up to 0.6 ± 0.4mm at a frequency of 100Hz. This study demonstrates that crack growth was greater at higher frequencies. The findings of this study may have implications in the early onset of osteoarthritis. This is because rapid heel-strike rise times have been implicated in the early onset of osteoarthritis., (Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The transition from a pediatric to adult health care system is challenging for many youths with epilepsy and their families. Recently, the Ministry of Health and Long-Term Care of the Province of Ontario, Canada, created a transition working group (TWG) to develop recommendations for the transition process for patients with epilepsy in the Province of Ontario. Herein we present an executive summary of this work. The TWG was composed of a multidisciplinary group of pediatric and adult epileptologists, psychiatrists, and family doctors from academia and from the community; neurologists from the community; nurses and social workers from pediatric and adult epilepsy programs; adolescent medicine physician specialists; a team of physicians, nurses, and social workers dedicated to patients with complex care needs; a lawyer; an occupational therapist; representatives from community epilepsy agencies; patients with epilepsy; parents of patients with epilepsy and severe intellectual disability; and project managers. Three main areas were addressed: (1) Diagnosis and Management of Seizures; 2) Mental Health and Psychosocial Needs; and 3) Financial, Community, and Legal Supports. Although there are no systematic studies on the outcomes of transition programs, the impressions of the TWG are as follows. Teenagers at risk of poor transition should be identified early. The care coordination between pediatric and adult neurologists and other specialists should begin before the actual transfer. The transition period is the ideal time to rethink the diagnosis and repeat diagnostic testing where indicated (particularly genetic testing, which now can uncover more etiologies than when patients were initially evaluated many years ago). Some screening tests should be repeated after the move to the adult system. The seven steps proposed herein may facilitate transition, thereby promoting uninterrupted and adequate care for youth with epilepsy leaving the pediatric system., (Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.)

The urinary bladder is an organ which facilitates the storage and release of urine. The bladder can develop tumours and bladder cancer is a common malignancy throughout the world. There is a consensus that there are differences in the mechanical properties of normal and malignant tissues. However, the viscoelastic properties of human bladder tumours at the macro-scale have not been previously studied. This study investigated the viscoelastic properties of ten bladder tumours, which were tested using dynamic mechanical analysis at frequencies up to 30Hz. The storage modulus ranged between 0.052MPa and 0.085MPa while the loss modulus ranged between 0.019MPa and 0.043MPa. Both storage and loss moduli showed frequency dependent behaviour and the storage modulus was higher than the loss modulus for every frequency tested. Viscoelastic properties may be useful for the development of surgical trainers, surgical devices, computational models and diagnostic equipment., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: Intensive Care Units (ICUs) provide life-supporting treatment; however, resources are limited, so demand may exceed supply in the event of pandemics, environmental disasters, or in the context of an aging population. We hypothesized that comprehensive national data on ICU resources would permit a better understanding of regional differences in system capacity., Methods: After the 2009-2010 Influenza A (H1N1) pandemic, the Canadian Critical Care Trials Group surveyed all acute care hospitals in Canada to assess ICU capacity. Using a structured survey tool administered to physicians, respiratory therapists and nurses, we determined the number of ICU beds, ventilators, and the ability to provide specialized support for respiratory failure., Results: We identified 286 hospitals with 3170 ICU beds and 4982 mechanical ventilators for critically ill patients. Twenty-two hospitals had an ICU that routinely cared for children; 15 had dedicated pediatric ICUs. Per 100,000 population, there was substantial variability in provincial capacity, with a mean of 0.9 hospitals with ICUs (provincial range 0.4-2.8), 10 ICU beds capable of providing mechanical ventilation (provincial range 6-19), and 15 invasive mechanical ventilators (provincial range 10-24). There was only moderate correlation between ventilation capacity and population size (coefficient of determination (R(2)) = 0.771)., Conclusion: ICU resources vary widely across Canadian provinces, and during times of increased demand, may result in geographic differences in the ability to care for critically ill patients. These results highlight the need to evolve inter-jurisdictional resource sharing during periods of substantial increase in demand, and provide background data for the development of appropriate critical care capacity benchmarks.

Performance of hip and knee implants reported by the designing surgeon(s) is often felt to be more optimistic than those observed in non-designer series. The purpose of this study is to compare the survivorship of hip and knee prostheses in series reported by designers with those in national joint registries. Fifteen different hip and knee implant results published by designers were identified and compared to four national registries. Thirty-two percent of comparisons performed demonstrated greater survivorship in the designer series compared to the registry, while 0% reported lower, and 68% demonstrated no difference. Two implants accounted for the majority (12/16) of the discordances. There was a lower (62%) concordance rate between the registries than between the designer series and registries (68%)., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this study is to understand conflicts in the ICU setting as experienced by clinicians and administrators and explore methods currently used to resolve such conflicts when there may be discordance between clinicians and families, caregivers or administration., Methods: Qualitative case study methodology using semi-structured interviews was used. The sample included community and academic health science centres in 16 hospitals from across the province of Ontario, Canada. A total of 42 participants including hospital administrators and ICU clinicians were interviewed. Participants were sampled purposively to ensure representation., Results: The most common source of conflict in the ICU is a result of disagreement about the goals of treatment. Such conflicts arise between the ICU and referring teams (inter-team), among members of the ICU team (intra-team), and between the ICU team and patients' family/substitute decision-maker (SDM). Inter- and intra-team conflicts often contribute to conflicts between the ICU team and families. Various themes were identified as contributing factors that may influence conflict resolution practices as well as the various consequences and challenges of conflict situations. Limitations of current conflict resolution policies were revealed as well as suggested strategies to improve practice., Conclusions: There is considerable variability in dealing with conflicts in the ICU. Greater attention is needed at a systems level to support a culture aimed at prevention and resolution of conflicts to avoid increased sources of anxiety, stress and burnout.

Purpose: In response to the challenges of an aging population and decreasing workforce, the provision of critical care services has been a target for quality and efficiency improvement efforts. Reliable data on available critical care resources is a necessary first step in informing these efforts. We sought to describe the availability of critical care resources, forecast the future requirement for the highest-level critical care beds and to determine the physician management models in critical care units in Ontario, Canada., Methods: In June 2006, self-administered questionnaires were mailed to the Chief Executive Officers of all acute care hospitals, identified through the Ontario government's hospital database. The questionnaire solicited information on the number and type of critical care units, number of beds, technological resources and management of each unit., Results: Responses were obtained from 174 (100%) hospitals, with 126 (73%) reporting one or more critical care units. We identified 213 critical care units in the province, representing 1789 critical care beds. Over half (59%) of these beds provided mechanical ventilation on a regular basis, representing a capacity of 14.9 critical care and 8.7 mechanically ventilated beds per 100,000 population. Sixty-three percent of units with capacity for mechanical ventilation involved an intensivist in admission and coordination of care. Based on current utilization, the demand for mechanically ventilated beds by 2026 is forecast to increase by 57% over levels available in 2006. Assuming 80% bed utilization, it is estimated that an additional 810 ventilated beds will be needed by 2026., Conclusion: Current utilization suggests a substantial increase in the need for the highest-level critical care beds over the next two decades. Our findings also indicate that non-intensivists direct care decisions in a large number of responding units. Unless major investments are made, significant improvements in efficiency will be required to maintain future access to these services.

The spatially controlled synthesis of poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic stationary phases in polyimide coated fused silica capillaries by visible light induced radical polymerisation using a three-component initiator and a 660 nm light emitting diode (LED) as a light source is presented here.

On January 31, 2007, Ontario's Critical Care Strategy hosted a workshop for healthcare providers examining cultural and religious perspectives on patient care in the intensive care unit (ICU). The workshop provided an opportunity for the Ministry of Health and Long-Term Care (MOHLTC) to engage service providers and discuss important issues regarding cultural and religious perspectives affecting critical care service delivery in Ontario. While a favourable response to the workshop was anticipated, the truly remarkable degree to which the more than 200 front-line healthcare providers, policy developers, religious and cultural leaders, researchers and academics who were in attendance embraced the need for this type of dialogue to take place suggests that discussion around this and other "difficult" issues related to care in a critical care setting is long overdue. Without exception, the depth of interest in being able to provide patient-centred care in its most holistic sense--that is, respecting all aspects of the patients' needs, including cultural and religious--is a top-of-mind issue for many people involved in the healthcare system, whether at the bedside or the planning table. This article provides an overview of that workshop, the reaction to it, and within that context, examines the need for a broad-based, non-judgmental and respectful approach to designing care delivery in the ICU. The article also addresses these complex and challenging issues while recognizing the constant financial and human resource constraints and the growing demand for care that is exerting tremendous pressure on Ontario's limited critical care resources. Finally, the article also explores the healthcare system's readiness and appetite for an informed, intelligent and respectful debate on the many issues that, while often difficult to address, are at the heart of ensuring excellence in critical care delivery.

Background: Standard rewarming methods for posttraumatic hypothermia are ineffective or require systemic heparinization. Centrifugal vortex blood pumps (CVBPs), heparin-bonded circuits, and, potentially, percutaneous access techniques, facilitate the institution of an extracorporeal circulation by noncardiac surgeons., Methods: Seven severely hypothermic patients requiring emergent operative intervention were rewarmed intraoperatively using the CVBP with heparin-bonded circuitry., Results: Patients were critically ill (average Injury Severity Score of 43.5 [SD, 13.6] for the traumatized patients). The mean temperature before rewarming was 31.5 degrees C (SD, 1.6 degrees C). The CVBP outflow site was the common femoral vein in all patients, with the inflow into the superficial femoral artery (n = 2), contralateral common femoral vein (n = 2), and internal jugular vein (n = 3). The mean time to rewarm to 37 degrees C was 73.3 (SD, 30.5) minutes. All patients survived the initial operation, although the ultimate survival was 43%., Conclusion: Noncardiac surgeons can effectively use an extracorporeal rewarming strategy incorporating a heparin-bonded CVBP to rapidly rewarm hypothermic coagulopathic patients undergoing surgery.

A rodent model of nicotine dependence has been developed based on continuous subcutaneous (s.c.) infusion of nicotine tartrate. Nicotine abstinence syndrome was precipitated by s.c. injection of the nicotinic antagonist mecamylamine, which freely crosses the blood-brain barrier. In contrast, the nicotinic antagonist hexamethonium crosses the blood-brain barrier very poorly. This study determined whether central or peripheral administration of hexamethonium could precipitate nicotine abstinence. In the first experiment, 26 nicotine-dependent rats were injected s.c. with 0.5, 5 or 10 mg/kg hexamethonium dichloride or saline alone and observed for 20 min. Few abstinence signs were observed in any group; there was no significant drug effect. In the second experiment, 18 rats were cannulated in the third ventricle and rendered nicotine dependent. One week later, rats were injected through the cannula with 12 or 18 ng hexamethonium or saline alone and observed for 20 min. Both dose groups differed significantly from the saline-injected group, and there was a significant positive linear trend of signs as a function of dose. The high dose had no significant effect in 14 nondependent rats. We conclude that hexamethonium is much more potent by the central route, and there is a major central nervous system component in nicotine dependence.

In a recently introduced rodent model of nicotine abstinence syndrome the observed behavioral signs closely resembled those typical of rat opiate abstinence syndrome. Nicotine-induced release of endogenous opioids may contribute to nicotine dependence; morphine potently reverses nicotine abstinence signs, while naloxone precipitates abstinence signs and prevents nicotine from alleviating them. Considerable evidence suggests that neuropeptide FF, an endogenous antiopiate peptide, contributes to opiate dependence. Third ventricle injection of neuropeptide FF precipitates abstinence syndrome in morphine-dependent rats, as does SC injection of its lipophilic analogs, dansyl-PQRFamide and dansyl-RFamide. Might NPFF also play a role in nicotine dependence? In the present study, SC injection of 15 or 25 mg/kg dansyl-RFamide or vehicle alone dose dependently precipitated an abstinence syndrome in nicotine-dependent rats. There was a significant, p < 0.01, positive linear trend of abstinence signs as a function of dose. Categories of abstinence signs had the same rank ordering by frequency as observed in spontaneous nicotine abstinence. Injection of 25 mg/kg dansyl-RFamide SC had no significant effect in nondependent rats.

Diagnosing colon cancer in its early stages would lower the mortality rate. The cotton-top tamarin, Saguinus oedipus, serves as a model for the study of human colon cancer. This New World monkey has a high incidence of colitis and colon cancer. The mouse anti-human monoclonal antibody BR55.2, with specificity for human colon adenocarcinoma, was biotinylated. Peripheral blood mononuclear cells (PBMC) from animals with colon cancer were fluorescently stained with the biotinylated BR55.2. These results showed the cross-reactivity of mouse anti-human colon cancer monoclonal antibody to the PBMC of cancerous tamarins. Antibodies from either cancerous or chronic colitis tamarins were also biotinylated. Fluorescently labeled cells were detected when PBMC from cancerous tamarins were incubated with biotinylated antibodies from cancerous tamarins. Cytofluorographic analysis also showed a significant 4.5-fold difference in the percentage of fluorescently labeled PBMC between cancerous and chronic colitis tamarins when stained with biotinylated antibodies from cancerous tamarins. DNA flow cytometry analysis showed that PBMC from cancerous tamarins have a higher percentage of aneuploid cells than PBMC from chronic colitis tamarins.

Preliminary observations have been carried out to look for radio signals associated with gravitational waves. Although inconclusive, the observations from five receivers in the British Isles suggest the value of pressing on with further experiments.