... In contrast, neither Parolari and colleagues31 nor van der Heijden and colleagues33 concurred as both meta-analyses, using a composite outcome that included stroke, found only a nonsignificant trend toward a lower incidence of stroke... more
... In contrast, neither Parolari and colleagues31 nor van der Heijden and colleagues33 concurred as both meta-analyses, using a composite outcome that included stroke, found only a nonsignificant trend toward a lower incidence of stroke with off-pump CABG surgery.31,33 A ...
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The article of Yoshitani et al.(1) regarding cerebral hypoperfusion and cognitive outcome after cardiac surgery has some limitations (1). The arterial carbon dioxide tension (Pa co 2) values reveal a large degree of variance. As Pa co 2... more
The article of Yoshitani et al.(1) regarding cerebral hypoperfusion and cognitive outcome after cardiac surgery has some limitations (1). The arterial carbon dioxide tension (Pa co 2) values reveal a large degree of variance. As Pa co 2 is a fundamental determinant of Sjv o ...
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We reported that a decline in cognitive performance 3 mo after coronary artery bypass grafting surgery is associated with palpable aortic atheroma, but not postoperative jugular bulb oxyhemoglobin saturation (SjO2) <50%.... more
We reported that a decline in cognitive performance 3 mo after coronary artery bypass grafting surgery is associated with palpable aortic atheroma, but not postoperative jugular bulb oxyhemoglobin saturation (SjO2) <50%. However, the effect of SjO2 on clinical neurologic findings is not known. S100beta is a possible surrogate biochemical marker of brain injury, and we report here the scored clinical neurologic findings in 98 patients from our previous study in relation to SjO2, cognitive performance, aortic atheroma, and S100beta. Patients underwent a scored neurologic examination and cognitive assessment the day before and 3 mo after coronary artery bypass grafting surgery. Intraoperatively, intermittent blood sampling was performed, and postoperatively, the area under the curve describing SjO2 <50% in relation to time was calculated from continuous jugular bulb reflectance oximetry. Palpation was used to assess the ascending aorta for the presence of atheroma. The jugular bulb concentration of S100beta was measured 6 h after completion of surgery. The neurologic score 3 mo after surgery did not correlate with either intra- or postoperative SjO2 (r = 0.111, P = 0.278; and r = -0.074, P = 0.467, respectively). The main determinant of neurologic score at 3 mo was the preoperative neurologic score (r(2) = 0.63, P < 0.001), whereas palpable atheroma of the ascending aorta made a small but significant contribution (r(2) = 0.034, P = 0.004). Neurologic and cognitive scores correlated before surgery (r = 0.226, P = 0.022) and at 3 mo after surgery (r = 0.348, P < 0.001). A preoperative neurologic deficit of two or more had a small but significant negative effect on cognitive performance at 3 mo (standardized beta = -0.097, P = 0.018). There was a significant univariate correlation between S100beta and the 3-mo neurologic score (r = -0.232, P < 0.05), but not a multivariate correlation (beta = -0.090, P = 0.156). Intraoperative jugular bulb oxyhemoglobin saturation (SjO2) and postoperative SjO2 <50% do not have an important influence on long-term neurologic outcome after coronary artery bypass graft surgery. Subtle preoperative neurology is associated with long-term cognitive decline, and aortic atheroma is a risk factor for both cognitive and neurologic decline.
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ABSTRACT Background: In the last two decades, coronary artery bypass grafting (CABG) surgery has increasingly been performed without cardiopulmonary bypass (CPB) that is ‘off-pump’. A strong motivation for performing CABG surgery off-pump... more
ABSTRACT Background: In the last two decades, coronary artery bypass grafting (CABG) surgery has increasingly been performed without cardiopulmonary bypass (CPB) that is ‘off-pump’. A strong motivation for performing CABG surgery off-pump was to avoid CPB which has been believed to cause of cognitive decline. However, accumulating evidence from systematic reviews and meta-analyses comparing on- and off-pump CABG surgery indicate that CPB may not be the cause of cognitive decline [1]. Several additional randomised controlled trials (RCTs) comparing cognition after on- and off-pump CABG surgery have been published since the last meta-analyses. Objectives: The aim of this study was to undertake a systematic review the literature and meta-analysis to compare cognition following on- and off-pump CABG surgery. Methods: RCTs comparing continuous measures of cognitive outcome after on- and off-pump CABG surgery were identified by literature searching. Data extraction enabled data from seven psychometric tests (Auditory Verbal Learning Test, Grooved Pegboard, Trail-Making A and B, Digit Symbol, Digit Span, and Stroop Colour Word Test) to be amalgamated. Data was grouped into early (< six months) and late (≥ six months) postoperative periods and analysed using Revman 5. Results: A systematic literature search conducted in Medline, Embase, PsychINFO and The Cochrane Library yielded 13 studies totalling 2285 patients that could be included in the meta-analysis. No significant differences were found between on- and off-pump groups in any of the psychometric tests in either early or late postoperative periods. Conclusions: To-date, this is the largest meta-analysis comparing cognition following on- and off-pump CABG surgery and the absence of difference is consistent with previous systematic reviews and meta-analyses. The results are highly suggestive that CPB may not be the cause cognitive decline associated with CABG surgery.
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... Philadelphia: WB Saunders, 1984:157. 3. Winnie AP. ... pump prime dose. Given a normal adult (65 kg body weight) the only difference between the 250 KIU/mL group in Nuttall's study and the Full-Dose group is the pump prime load... more
... Philadelphia: WB Saunders, 1984:157. 3. Winnie AP. ... pump prime dose. Given a normal adult (65 kg body weight) the only difference between the 250 KIU/mL group in Nuttall's study and the Full-Dose group is the pump prime load (88 mg vs. 280 mg). ...
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Reductions in cerebral venous oxyhemoglobin saturation (SjO2) occur during the rewarming phase of hypothermic cardiopulmonary bypass (CPB). We prospectively investigated the effects of propofol on these reductions in SjO2 (SjO2... more
Reductions in cerebral venous oxyhemoglobin saturation (SjO2) occur during the rewarming phase of hypothermic cardiopulmonary bypass (CPB). We prospectively investigated the effects of propofol on these reductions in SjO2 (SjO2 <50%). Fiberoptic jugular bulb catheters were inserted in 30 patients undergoing coronary artery bypass grafting. Patients were randomly allocated to a test or control group. Test group patients (n = 15) received a propofol IV infusion titrated to electroencephalographic burst suppression during CPB. No significant differences in SjO2 <50% were found between the groups either by blood sampling and bench oximetry or fiberoptic oximetry. The arteriovenous difference in lactate concentration became negative in 59 of 120 samples. Propofol was associated with an increased incidence of hypotension (mean arterial pressure <50 mm Hg) (P = 0.023), an increased requirement for vasoconstrictor therapy (P = 0.025), and increases in the lactate oxygen index (P < 0.01). Propofol, when administered in doses that produce electroencephalographic burst suppression, does not attenuate the frequency or extent of reductions of SjO2 below 50% during rewarming from hypothermic CPB. However, it is associated with arterial hypotension and an increase in cerebral anaerobic metabolism. Reductions in cerebral venous oxyhemoglobin saturation during the rewarming phase of cardiopulmonary bypass may be related to brain injury. When administered in doses sufficient to produce electroencephalographic burst suppression, propofol did not attenuate the frequency or extent of such reductions in cerebral venous oxyhemoglobin saturation.
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ABSTRACT The field of Web development has evolved and diversified significantly in recent years, and narrowing the gap between the requirements of academia and the demands of industry remains a challenge. Moreover, many faculty members... more
ABSTRACT The field of Web development has evolved and diversified significantly in recent years, and narrowing the gap between the requirements of academia and the demands of industry remains a challenge. Moreover, many faculty members often struggle with knowing “how much” of a particular subject they should teach to their students and at what level. This small-scale, exploratory study seeks to uncover the existence of “threshold concepts” within Web development. Threshold concepts are the fundamental concepts which, once mastered, allow a learner to progress to a deeper understanding of a subject. An online questionnaire was sent out to 24 instructors within UK higher education institutions who teach Web development subjects. Nine participants responded to the questionnaire and interviews were conducted with five to discuss and expand on the responses provided, resulting in the identification of four areas that were perceived as difficult for students to grasp when learning Web development. Analysis of these areas suggests that threshold concepts do exist within the subject and we offer up two candidates for the field of Web development: basic programming principles and decomposition and abstraction. Designing a curriculum based on threshold concepts and less on the latest methods, tools, and techniques can go a long way in helping students to become experts in their chosen discipline.
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Abstract Many patients who have cardiac surgery experience cerebral complications. Recently, the focus of interest has shifted from gross sequelae, such as stroke, to less conspicuous, but more frequent, neurologic and cognitive deficits.... more
Abstract Many patients who have cardiac surgery experience cerebral complications. Recently, the focus of interest has shifted from gross sequelae, such as stroke, to less conspicuous, but more frequent, neurologic and cognitive deficits. Although subtle, these ...
Metabolic acidosis is a frequent complication of cardiopulmonary bypass (CPB). Commonly, its cause is ascribed to hypoperfusion; however, iatrogenic causes, related to the composition and volume of intravascular fluids that are... more
Metabolic acidosis is a frequent complication of cardiopulmonary bypass (CPB). Commonly, its cause is ascribed to hypoperfusion; however, iatrogenic causes, related to the composition and volume of intravascular fluids that are administered, are increasingly being recognized. The aim of this study was to determine if metabolic acidosis during CPB was associated with hypoperfusion, change in strong ion difference (SID) or haemodilution. Forty-nine patients undergoing cardiac surgery using CPB in the Royal Infirmary of Edinburgh (RIE) or the HCI, Clydebank were included in the study. Arterial blood samples were aspirated before induction of anaesthesia and the end of CPB. Samples were subjected to blood gas analysis and measurement of electrolytes and lactate. Changes in concentrations were then calculated. Change variables that were found to be significant (p < 0.1) univariate correlates of the change in hydrogen ion concentration were identified and entered into a multivariate re...
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For over four decades, pump flow rate during cardiopulmonary bypass (CPB) has been estimated using body surface area (BSA). As patients presenting for heart surgery are increasingly obese, this approach may no longer be appropriate and... more
For over four decades, pump flow rate during cardiopulmonary bypass (CPB) has been estimated using body surface area (BSA). As patients presenting for heart surgery are increasingly obese, this approach may no longer be appropriate and other estimates of systemic metabolism should be used, such as body mass index and lean body mass. Mixed venous oxygen saturation (SvO2) is a robust and independent estimate of the global efficacy of CPB. The aim of this study was to determine which factors, including body surface area, body mass index and lean body mass, best predict SvO2 during CPB. Forty-eight patients undergoing elective cardiac surgery requiring CPB were studied. Patients' height, weight and skinfold thickness at four sites (biceps, triceps, subscapularis and suprailiac) were measured. Body surface area, lean body mass and body mass index were then calculated. Pump flow rate was maintained at 2.4 L/min/ m2 during CPB as per standard unit protocol. Arterial and mixed venous bl...
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ABSTRACT Repurposing of data raises a number of issues for use across the disciplines of climate science and social science. The issues we present are results of the work we are currently carrying out as part of the Data Conservancy... more
ABSTRACT Repurposing of data raises a number of issues for use across the disciplines of climate science and social science. The issues we present are results of the work we are currently carrying out as part of the Data Conservancy Project1 which aims to preserve data for long-term known and unanticipated use over time, across disciplines and over a variety of spatial, temporal and organizational scales.
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Theoretically, systemic carbon dioxide (VCO2) production should be an alternative means to systemic oxygen uptake (VO2) for estimating the global efficacy of cardiopulmonary bypass (CPB). This study compared two methods of estimating... more
Theoretically, systemic carbon dioxide (VCO2) production should be an alternative means to systemic oxygen uptake (VO2) for estimating the global efficacy of cardiopulmonary bypass (CPB). This study compared two methods of estimating VCO2: Fick&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s principle and oxygenator exhaust carbon dioxide (CO2) output. Both of these estimates were then compared with VO2. Fifty-one patients (39 male and 12 female) undergoing elective cardiac surgery requiring CPB were studied. Blood sampling was performed and measurements recorded during active cooling, environmental cooling/stable hypothermia and during rewarming. Blood samples were measured for CO2 tension from which content was estimated. VCO2 was calculated as the product of the arteriovenous difference in CO2 content and pump flow rate (Fick&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s principle), or the fresh gas flow rate and concentration of the oxygenator exhaust CO2 (output technique). Over all measurements, method comparison analysis revealed a large mean bias of 41 (95% confidence intervals (CI) 32-50) mL/min with very wide limits of agreement (-23, 105 mL/min). Regression analysis found that the bias was also proportional to the size of measurement (beta = 0.75 (95% CI 0.55, 0.95)). Although both methods of VCO2 correlated significantly with VO2 (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01), regression analysis found that the coefficients (beta) of both techniques had wide CI (Fick&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s principle: beta = 1.37 (95% CI 1.20, 1.54); output technique: beta = 0.58 (95%CI 0.44, 0.71)). In conclusion, both techniques of VCO2 cannot be used interchangeably, and both are imprecisely related to VO2 as estimated by Fick&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s principle.
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Blood transfusion remains one of the commonest interventions carried out upon individuals undergoing cardiac surgery. Despite this, the scientific rationale on which to base this decision is limited. Currently, hemoglobin concentration is... more
Blood transfusion remains one of the commonest interventions carried out upon individuals undergoing cardiac surgery. Despite this, the scientific rationale on which to base this decision is limited. Currently, hemoglobin concentration is often used as the sole guide as to when a transfusion may be required. A fall in hemoglobin concentration is often assumed to be associated with a similar drop in red cell volume. A review was undertaken of all the relevant peer-reviewed literature to determine what factors we should consider when deciding to transfuse elective cardiac surgery patients. The large fluid load associated with cardiac surgery, primarily from the cardiopulmonary bypass circuit, may have a significant dilutional effect. In such a scenario, several interlinked protective mechanisms may ensure that tissue oxygenation is maintained, including a reduction in blood viscosity, a decrease in systemic afterload, and an increase in cardiac output. Furthermore, oxygen requirements during the initial perioperative phase are reduced because of the effect of general anesthesia and hypothermia during cardiopulmonary bypass. When deciding to transfuse, consideration should be given to red cell volume, circulatory status, and oxygen requirement. It is possible that such an all-encompassing approach would reduce the incidence of unnecessary, and potentially counterproductive, red cell transfusion in cardiac surgery.
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Research Interests: Cardiothoracic Surgery, Clinical Trial, Global Health, Statistical Analysis, Cardiac Surgery, and 18 moreHumans, Hyperglycemia, Blood Glucose, Atrial Fibrillation, Randomised Controlled Trial, Length of Stay, Meta Analysis, Systematic review, Clinical Sciences, Intensive Care Unit, Research Needs, Morbidity, Survival Rate, Mechanical Ventilation, Prognosis, Data Extraction, Confidence Interval, and Postoperative care
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The primary aim was to poll the opinions of cardiac anesthesiologists and surgeons as to the effect of the suspension of the license for aprotinin on patients undergoing cardiac surgery. A mailed questionnaire. United Kingdom. Members of... more
The primary aim was to poll the opinions of cardiac anesthesiologists and surgeons as to the effect of the suspension of the license for aprotinin on patients undergoing cardiac surgery. A mailed questionnaire. United Kingdom. Members of the Association of Cardiothoracic Anaesthetists and the Society for Cardiothoracic Surgery in Great Britain and Ireland with a UK address. A structured questionnaire. Of the 546 dispatched surveys, 285 (52%) were returned. While the majority of respondents (61%) felt it had not had any effect, 29% of respondents felt the suspension of the license for aprotinin had had a detrimental effect on patient care and 2% an extremely detrimental effect. Eight percent of respondents reported a beneficial effect. Since license suspension, the reported use of aprotinin had declined and tranexamic acid use had risen. The majority of respondents reported no change in the use of packed red cells (66%), blood products (53%), mechanical cell salvage (84%), factor VIIa (79%), or frequency of reopening for bleeding (65%). Respectively, 32%, 45%, 24%, and 20% of respondents reported a perceived increased use of these products, and 30% reported an increased frequency of reopening for bleeding. Apart from knowledge regarding local aprotinin stock, there was no significant difference in opinions between surgeons and anesthesiologists. While the majority of respondents felt that the suspension of the license for aprotinin had no effect, almost a third felt it had impacted negatively on the care of patients undergoing cardiac surgery.
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... Philadelphia: WB Saunders, 1984:157. 3. Winnie AP. ... pump prime dose. Given a normal adult (65 kg body weight) the only difference between the 250 KIU/mL group in Nuttall's study and the Full-Dose group is the pump prime load... more
... Philadelphia: WB Saunders, 1984:157. 3. Winnie AP. ... pump prime dose. Given a normal adult (65 kg body weight) the only difference between the 250 KIU/mL group in Nuttall's study and the Full-Dose group is the pump prime load (88 mg vs. 280 mg). ...
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In their present work, Scott et al.(1) have overcome most of our criticisms (2) of their retrospective study of thoracic epidural analgesia for coronary artery bypass grafting surgery (3). However, it is unclear in their present study... more
In their present work, Scott et al.(1) have overcome most of our criticisms (2) of their retrospective study of thoracic epidural analgesia for coronary artery bypass grafting surgery (3). However, it is unclear in their present study whether epidural analgesia prevents or ...
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We reported that a decline in cognitive performance 3 mo after coronary artery bypass grafting surgery is associated with palpable aortic atheroma, but not postoperative jugular bulb oxyhemoglobin saturation (SjO2) &amp;amp;lt;50%.... more
We reported that a decline in cognitive performance 3 mo after coronary artery bypass grafting surgery is associated with palpable aortic atheroma, but not postoperative jugular bulb oxyhemoglobin saturation (SjO2) &amp;amp;lt;50%. However, the effect of SjO2 on clinical neurologic findings is not known. S100beta is a possible surrogate biochemical marker of brain injury, and we report here the scored clinical neurologic findings in 98 patients from our previous study in relation to SjO2, cognitive performance, aortic atheroma, and S100beta. Patients underwent a scored neurologic examination and cognitive assessment the day before and 3 mo after coronary artery bypass grafting surgery. Intraoperatively, intermittent blood sampling was performed, and postoperatively, the area under the curve describing SjO2 &amp;amp;lt;50% in relation to time was calculated from continuous jugular bulb reflectance oximetry. Palpation was used to assess the ascending aorta for the presence of atheroma. The jugular bulb concentration of S100beta was measured 6 h after completion of surgery. The neurologic score 3 mo after surgery did not correlate with either intra- or postoperative SjO2 (r = 0.111, P = 0.278; and r = -0.074, P = 0.467, respectively). The main determinant of neurologic score at 3 mo was the preoperative neurologic score (r(2) = 0.63, P &amp;amp;lt; 0.001), whereas palpable atheroma of the ascending aorta made a small but significant contribution (r(2) = 0.034, P = 0.004). Neurologic and cognitive scores correlated before surgery (r = 0.226, P = 0.022) and at 3 mo after surgery (r = 0.348, P &amp;amp;lt; 0.001). A preoperative neurologic deficit of two or more had a small but significant negative effect on cognitive performance at 3 mo (standardized beta = -0.097, P = 0.018). There was a significant univariate correlation between S100beta and the 3-mo neurologic score (r = -0.232, P &amp;amp;lt; 0.05), but not a multivariate correlation (beta = -0.090, P = 0.156). Intraoperative jugular bulb oxyhemoglobin saturation (SjO2) and postoperative SjO2 &amp;amp;lt;50% do not have an important influence on long-term neurologic outcome after coronary artery bypass graft surgery. Subtle preoperative neurology is associated with long-term cognitive decline, and aortic atheroma is a risk factor for both cognitive and neurologic decline.
Research Interests:
Research Interests:
The article of Yoshitani et al.(1) regarding cerebral hypoperfusion and cognitive outcome after cardiac surgery has some limitations (1). The arterial carbon dioxide tension (Pa co 2) values reveal a large degree of variance. As Pa co 2... more
The article of Yoshitani et al.(1) regarding cerebral hypoperfusion and cognitive outcome after cardiac surgery has some limitations (1). The arterial carbon dioxide tension (Pa co 2) values reveal a large degree of variance. As Pa co 2 is a fundamental determinant of Sjv o ...