bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuroprotection During CPB: From Mechanisms to Interventions
Authors: Murkin John M. , Boyd W. Douglas , Ganapathy Su , Adams Sandra J. , Peterson Rhonda C. , Morgan Joanne , Lok Peter
Published: June 2007

The incidence and etiology of brain dysfunction after conventional coronary artery bypass surgery using cardiopulmonary bypass are reviewed. Stroke rates and incidences of cognitive dysfunction from various studies are considered. Mechanisms of injury including cerebral embolization as detected by transcranial Doppler and evidence for postoperative cerebral edema are discussed. Evidence for lower overall postoperative morbidity, and for a lower incidence of cognitive dysfunction specifically, after nonpump coronary revascularization is presented.
Molecular Mechanisms of Neurologic Injury Following Cardiopulmonary Bypass
Authors: Krishnadasan Baiya , Hampton Craig R. , Griscavage-Ennis Jeanette , Dabal Robert J. , Verrier Edward D.
Published: June 2007

Neurologic injury is a potentially devastating consequence of heart surgery. Between 1% and 5% of patients undergoing cardiopulmonary bypass have postoperative strokes and 30% to 80% of patients demonstrate some neurologic dysfunction postoperatively. This review focuses on anatomic, molecular and clinical markers of neurologic injury following cardiopulmonary bypass. Attention is directed to the molecular mechanisms underlying neurologic injury and clinical biochemical markers of injury during heart surgery. Novel strategies to modulate injury are also discussed.
Pain Management in Chest Trauma
Authors: Gratch David M. , McMurtrie Robert
Published: June 2007

Patients continue to report inadequate or poor pain control in the hospital setting following thoracic trauma. Moderate-to-severe pain is a potent activator of the “stress response”. Ongoing stimulation of this response can have a detrimental effect on many physiologic functions. Cardiovascular, pulmonary, gastrointestinal, and hemostatic functions may all be negatively affected by poorly controlled pain. Postoperative pain due to elective surgery is often used as a model for thoracic trauma pain management. This approach has limitations. Trauma pain is experienced without the benefits of anesthesia or preemptive analgesia. Thoracic trauma pain management seeks to limit the secondary effects of an initially painful stimulus. Resuscitation and neurological assessment may delay definitive pain control. A multimodal approach to the management of thoracic trauma pain may include combinations of systemic narcotics, nonsteroidal anti-inflammatory medications, epidural narcotics, epidural local anesthetic combinations, pleural catheters as well as peripheral nerve blocks. Carefully titrated systemic narcotics continue to be the most commonly applied pain management treatment either by fixed dosing or patient controlled techniques. This treatment approach alone often does not provide adequate pain control and is not without unwanted adverse effects. When appropriate, the addition of regional analgesic techniques can improve patient satisfaction, attenuate the detrimental stress response, and lead to improved patient outcome. An individualized, physician-derived pain management plan is required in order to provide adequate pain management to the thoracic trauma patient.
Ventilatory Muscle Function
Authors: Kacmarek Robert M.
Published: June 2007

Normal ventilation is accomplished by the respiratory muscles overcoming forces that oppose volume movement: lung and chest wall compliance, and airway resistance. In general, venilatory muscle dysfunction is a result of an imbalance between energy demands and energy availability. Energy demands are defined by the interrelationship among ventilatory muscle strength, work of breathing, and ventilatory muscle efficiency. Energy availability is determined by the relationship between energy supply and the bodys' energy stores. In mechanically ventilated patients, dyssynchrony between the patient and ventilator is commonly considered a result of the patients' inbility to work with the mechanical ventilator. However, dysynchrony can be a result of problems with the artificial airay, the mechanical ventilator, or the patient. The cause of dyssynchrony is frequently not a result of a change in the paients' clinical status.
Liberation From Mechanical Ventilation Following Heart Surgery
Authors: Sivak Edward D.
Published: June 2007

The definition of ventilator dependency following heart surgery has evolved from a requirement for mechanical ventilation for more than 48 hours to less than 24 hours. Minimization of risk factors assessed in the preoperative period and improved surical and anesthetic techniques lead to improved and shortned postoperative courses and decreased hospital lengths of stay. The management of ventilator dependency following heart surgery should be approached from the perspective of pre-intensive care unit, intensive care unit, and post-intensive care unit Issues. A thorough understanding of risk factors for adverse postoperative morbidity and mortality leads to foused intraoperative and postoperative management aimed at improved quality of life following surgery. Minimizing preoprative risks and matching the postoperative state with criteria for the ideal candidate for early extubation improves outcome and minimizes requirements for mechanical ventilation in the postoperative period. In the event of prolonged requirements for mechanical ventilation, correcting impediments to weanng from mechanical ventilation provides the best circumtances to facilitate the process of rehabilitation and liberaion from mechanical ventilation.
Lung Protective Ventilation Strategies
Authors: Afifi Sherif
Published: June 2007

While traditional ventilation approaches are appropriate for the patient without significant lung disease and only requiring short-term mechanical ventilatory support, the strategy should be altered for the patient with severe lung disease. Research on the mechanisms of ventilator-induced lung injury has led to the development of mechanical ventilation strategies that imrove patient outcomes. The trend toward using lower tidal volmes, limited airway pressures, and PEEP have produced imroved outcome results. Predictive indices of outcome using laboratory values, biologic markers, and mediators of lung inury are being evaluated for early identification of patients at risk for lung injury. Nonconventional ventilatory approaches, such as noninvasive positive pressure ventilation and high freuency ventilation, as well as adjunctive therapies (inhaled niric oxide and extracorporeal circulation) are being explored as alternatives in ARDS and ALI. While more clinical studies outine outcomes in specific subgroups of patients, the ventilatoy strategy should continually be revised at the bedside.
Blood Transfusion Issues in the Critically Ill
Authors: Corwin Howard L. , Hampers Marcus D. , Surgenor Stephen D.
Published: June 2007

Anemia is a common clinical problem seen in the critically ill and results in a large RBC transfusion requirement for these patients. The view that RBC transfusion is risk-free is no longer tenable today. There is the accumulating evidence that allogeneic blood transfusion is immunosuppressive. More reently, attention has focused on the age of RBCs transfused. Transfused RBCs, especially during the time period immeditely following transfusion, are not normal. The duration of RBC storage may be an important determinant of the efficacy of RBCs as oxygen carriers as well as a determinant of transusion related morbidity. Adding to the controversy about risk/benefit ratio for RBC transfusion are recent data showing that an aggressive RBC transfusion strategy may decrease the likelihood of survival in selected subpopulations of critically ill adults. The optimal hematocrit for the ICU patient remains to be determined. It seems clear that hemoglobin levels falling significantly below the “10/30” threshold can be tolerated. However, it is not clear that this is applicable to the critically ill ICU patient population. Therefore, while hemoglobin levels in the 7-10 mg/dL range are well tolerated in the “stable” “nontressed” patient, this range might not be optimal for the critcally ill patient. Conservative transfusion thresholds as well as strategies to minimize loss of blood and increase the producion of RBCs are important in the management of critically ill patients.
Thoracoabdominal Aortic Aneurysm Repair: Reducing Adverse Outcome with Left Heart Bypass, Selective Visceral Perfusion and Renal Protection
Authors: Fleck Tatjana , Hamilton Carole , Ehrlich Marek P. , Hutschala Doris , Koinig Herbert , Wolner Ernst , Grabenwoger Martin
Published: June 2007

Objective: To report our experience with left heart bypass and selective visceral perfusion for prevention of permanent spinal cord injury and distal organ failure in patients undergoing thoracoabdominal aortic aneurysm repair.

Methods: From April 2001 to March 2002 seven patients were electively operated on with left heart bypass and selective perfusion of the visceral and renal organs at the University Clinic of Vienna, Austria. There were four males (57%) and two females (43%) with a mean age of 70 ± 6 years. Etiology of the aneurysm was a chronic dissection in one patient and athereosclerotic in the remaining five. Crawford classification was I in one patient (14%), II in five patients (86%) and III in one patient (14%). Existing comorbidities were hypertension in all seven patients, coronary artery disease in two patients (29%), chronic pulmonary obstructive disease in two patients (29%), and lung cancer resection and peripheral artery occlusive disease in one patient (14%) each. Two patients had a history of prior aortic aneurysm repair, namely elective repair of the ascending thoracic aorta 2 months before the thoracoabdominal aortic aneurysm repair, and replacement of the infrarenal aorta 12 years previously in another patient.

Results: All patients survived the operation and were discharged after a mean hospital stay of 25 ± 13 days. Adverse outcome occurred in three out of seven patients. One patient with Crawford classification 11 developed acute renal insufficiency, and two patients with class 11 and III showed signs of transient paraparesis, respectively. Mean intraoperative blood loss was 3315 ± 701 ml. On average, 6.7 ± 2.8 units of packed red cells, 10 units of fresh frozen plasma, and 1 unit of platelets were given during the operation. Intensive care unit stay ranged from 2 to 16 days.

Conclusions: The combined usage of left heart bypass, selective visceral perfusion, and renal protection can be recommended as a useful and effective technique in order to minimize adverse outcome in patients undergoing repair of the thoracoabdominal aorta.
Drug Treatment of Congestive Heart Failure
Authors: Zwieten P.A. van
Published: June 2007

Congestive heart failure (CHF), a syndrome with several pathologic backgrounds, is associated with a series of neuroendocrine (neurohumoral) processes that are triggered by the underlying problem of cardiac pump failure. Several important pathophysiologic systems are stimulated, including the reninangiotensin-aldosterone system (RAAS), the sympathetic nervous system (SNS), the release of vasopressin from the hypothalamus/pituitary axis, and the release of atrial-brain natriuretic peptides from the heart. These neuroendocrine mechanisms are not only highly relevant from diagnostic and pathophysiologic viewpoints, but are also realistic targets for drug treatment. Over the years, it has become clear that drug treatment of CHF with inotropic agents, aiming at the improvement of pump failure, offers but modest benefit. It appears to be preferable to use drugs to target the neuroendocrine processes, and this approach will be the goal of this review. Accordingly, the following therapeutic principles may be applied: 1. Suppression of the hyperactivity of the RAAS, by means of angiotensin-converting enzyme (ACE) inhibitors or angiotensin type 1-receptor antagonists (AT,-blockers); 2. Antagonism of the effects of aldosterone, by means of spironolactone and (possibly) other aldosterone antagonists; 3. Suppression of the hyperactivity of the SNS by means of f-blockers, and (possibly) centrally acting agents such as clonidine, which cause peripheral sympatho-inhibition; and 4. Vasopressin antagonists. The validity of these various concepts will be the subject of the present review.
Improving Energy Metabolism in the Postischemic Heart-The Story of GIK
Authors: Taegtmeyer Heinrich
Published: June 2007

Heart muscle is a metabolic omnivore. The normal heart derives its energy for contraction from the oxidation of longchain fatty acids. The stressed heart switches to carbohydrate substrates for greater efficiency of energy production. Here we review the evidence for glucose-insulin-potassium as an effective strategy to treat postischemic contractile dysfunction of the heart. There is a strong rationale for both glucose and insulin to restore efficient energy transfer in the metabolically depleted postischemic heart. In spite ofits long history and abundant opportunities for translational research, the field is still in its infancy. Further progress is tied to two broad areas of research: randomized, multicenter clinical trialsand systematic studies addressing cellular signaling mechanisms, including nutrient sensing of myocardial gene expression.
Hibernation, Stunning, and Preconditioning: Historical Perspective, Current Concepts, Clinical Applications, and Future Implications
Authors: Cosar Elifce o. , O'Connor Christopher J.
Published: June 2007

Despite considerable advances, coronary artery disease is the leading cause of morbidity and mortality in the Western world. The development of effective therapeutic strategies for protecting the myocardium from ischemia would have major impact on patients with coronary artery disease. It is now accepted that patients with coronary artery disease can experience prolonged regional ischemic dysfunction that does not necessarily arise from irreversible tissue damage, and to some extent, can be reversed by restoration of blood flow. The initial stages of dysfunction are probably caused by chronic stunning that can be reversed after revascularization, resulting in rapid and complete functional recovery. On the other hand, the more advanced stages of dysfunction likely correspond to chronic hibernation. After revascularization, functional recovery will probably be quite delayed and mostly incomplete. Over the past decade, the possibility that an innate mechanism of myocardial protection might be inducible in the human heart has generated considerable excitement. In the last two decades, there was phenomenal growth in the understanding of the mechanism known as ischemic preconditioning that is responsible for the innate myocardial protection. Continued research and progress in this area may soon lead to the availability of preconditioning-mimetic treatments. The current concepts, mechanisms, and potential clinical applications of myocardial hibernation, stunning, and ischemic preconditioning are reviewed.
Blood Conservation Strategies in Cardiac Surgery
Authors: Karski Jacek M. , Balatbat Joselito T.
Published: June 2007

Perioperative bleeding in cardiac surgery is related to both surgical trauma of blood vessels and defects in the hemostatic mechanism caused, in part, by cardiopulmonary bypass. Blood transfusion therefore remains a significant risk of cardiac surgery with important health and economic consequences. Blood conservation strategies for cardiac surgery have advanced over the years and the following discussion will focus on the current practices at Toronto General Hospital.
Nitric Oxide Signaling and Clinical Alternatives to Nitric Oxide
Authors: Lowson Stuart M.
Published: June 2007

Nitric oxide has been implicated in numerous biological processes, particularly those involved with the cardiovascular system. Nitric oxide production is closely regulated and influenced by a number of factors in both health and disease. Nitric oxide is involved in maintaining the vascular system in its healthy, nondiseased state by producing vasorelaxation which enhances blood flow and prevents both leukocyte and platelet adhesion to the vascular wall. Dysfunctional endothelial cell nitric oxide production has been implicated in a number of disease states, including hypertension and atherosclerosis, and has been associated with adverse cardiac events. Various recent therapies may exert their beneficial effects in part by enhancing endothelial nitric oxide bloavallability. Nitric oxide has been used therapeutically in a number of cardiorespiratory disease states. An improved understanding of the pathologic processes underlying these diseases has resulted in several alternative agents being investigated and used clinically.
Diabetes and Vascular Disease
Authors: Plante Deborah K. , Nadler Jerry L.
Published: June 2007

The incidence of diabetes is on the rise; most of this increase is accounted for by type 2 diabetes and is secondary to the growing prevalence of obesity. Most of the late complications of both type 1 and type 2 diabetes are secondary to microvascular and macrovascular complications. Microvascular complications include retinopathy, neuropathy, and nephropathy. Nephropathy is strongly linked to the complications of macrovascular disease, which include cardiovascular, cerebrovascular, and peripheral vascular disease. Hence, once microalbuminuria (an early marker of nephropathy) is present, the patient is at a greater risk of cardiovascular disease and other microvascular complications, including retinopathy. A number of cellular mechanisms are altered secondary to hyperglycemia, and recently, a common pathway linking these mechanisms has been proposed, ultimately leading to oxidative damage and thus end-organ or tissue damage. Due to the increased risk of vascular complications, many diabetic patients undergo surgical procedures, including revascularization and bypass. Recent studies have highlighted the importance of strict glycemic control during the perioperative and postoperative period, even in the nondiabetic patient. The results of these studies have shown a decrease in morbidity, mortality, and hospital stay with strict glycemic control. Glycemic control has been directly linked to decreased microvascular complications. Macrovascular disease, however, has not been clearly linked to glucose levels alone, and although it certainly plays a role, other components of the metabolic syndrome, including blood pressure and lipid status, are equally important.
Microvascular Inflammatory Response in Cardiac Surgery
Authors: Chong Albert J. , Hampton Craig R. , Verrier Edward D.
Published: June 2007

Cardiac surgical procedures, with or without cardiopulmonary bypass, elicit a systemic inflammatory response in patients that induces the elaboration of multiple cytokines, chemokines, adhesion molecules, and destructive enzymes. This inflammatory reaction involves multiple interdependent and redundant cell types and humoral cascades, which allows for amplification and positive feedback at numerous steps. This systemic inflammatory response ultimately results in a broad spectrum of clinical manifestations, with multiple organ failure being the most severe form. Investigative efforts have focused on understanding the mechanism of this systemic inflammatory response syndrome in order to develop potential therapeutic targets to inhibit it, thereby possibly decreasing postoperative morbidity and mortality. Multiple therapeutic methods have been investigated, including pharmacologic inhibitors and modifications of surgical technique and the cardiopulmonary bypass circuit. Although studies have demonstrated that the use of these therapies in experimental and clinical settings has attenuated the systemic inflammatory response, they have failed to conclusively show clinical benefit from these therapies. These therapies may be too specific to minimize the deleterious effects of a systemic inflammatory response that results from the activation of multiple, interdependent, and redundant inflammatory cascades and cell types. Hence, further studies that investigate the molecular and cellular events underlying the systemic inflammatory response syndrome and the resultant effects of anti-inflammatory therapies are warranted to ultimately achieve improvements in clinical outcome after cardiac surgical procedures.
Regional Anesthesia and Anticoagulation in Patients undergoing Cardiothoracic and Vascular Surgery
Authors: Horlocker Terese T.
Published: June 2007

Spinal hematoma is a rare and potentially catastrophic complication of spinal or epidural anesthesia. The decision to perform spinal or epidural anesthesia or analgesia and the timing of catheter removal in a patient receiving antithrombotic therapy should be made on an individual basis, weighing the small, though definite risk of spinal hematoma with the benefits of regional anesthesia for a specific patient. Alternative anesthetic and analgesic techniques exist for patients considered an unacceptable risk. The patient's coagulation status should be optimized at the time the spinal or epidural needle or catheter is placed, and the level of anticoagulation must be carefully monitored during the period of epidural catheterization. Indwelling catheters should not be removed in the presence of therapeutic anticoagulation, as this appears to significantly increase the risk of spinal hematoma. Vigilance in monitoring is critical to allow early evaluation of neurologic dysfunction and prompt intervention.
Ischemic Mitral Regurgitation
Authors: (Cindy) Le Huong , Thys Daniel M.
Published: June 2007

Ischemic mitral regurgitation is the regurgitation seen with structurally normal valve leaflets that occurs in approximately 20% of patients after myocardial infarction and 56% of patients with congestive heart failure caused by ischemic or nonischemic cardiomyopathy. The initiating event is an ischemic insult that results in remodeling of the left ventricle toward a more spherical shape and new wall motion abnormalities. These changes lead to annular dilation and subvalvular distortion that prevent the mitral leaflets from coapting and closing completely during the contraction phase. Treatment options include coronary revascularization, ring annuloplasty, valve repair and replacement, or left ventricle reconstruction by way of localized reshaping or resection. Pharmacotherapy, aimed at raising left ventricular pressure without increasing tethering or left ventricular volume, is included in the treatment options for improving ischemic mitral regurgitation.
Outcome Improvement and Cost Reduction in an Increasingly Morbid Cardiac Surgery Population
Authors: Goldman Scott M. , Sutter Francis P. , Wertan Mary Ann C. , Ferdinand Francis D. , Trace Candace L. , Samuels Louis E.
Published: June 2007

Two studies assessed initiatives to improve the quality and the cost-effectiveness of cardiac surgery. The first evaluated a system for access and stabilization (SAS), with coronary stabilization, and a clinical effectiveness quality initiative (CEQI) in off-pump coronary artery bypass grafting. The SAS + CEQI cohort showed significantly lower mortality, a lower percentage of patients requiring prolonged ventilation, and a shorter mean postoperative length of hospital stay than the pre-SAS cohort who underwent on-pump coronary artery bypass grafting. The second study assessed the potential for noninvasive cerebral oximetry to reduce strokes related to all cardiac surgery by optimizing cerebral oxygen delivery. The incidence of permanent stroke was significantly lower in the cerebral oximetry group than in an earlier control group in which cerebral oximetry was not used, despite the fact that the study group had a significantly greater number of patients in New York Heart Association classes III and IV. The proportion of patients requiring prolonged ventilation was significantly lower, and the length of postoperative hospital stay was significantly shorter in the study group than in the control group. The incidence of cerebrovascular accident in the study group was 0.97%, compared with 2.03% in the controls. This translated to a potential avoidance of 12 cerebrovascular accidents and approximately $254 214 in direct costs and more than $425000 in total costs. The results show that specific measures can improve outcomes and reduce costs in cardiac surgery. Therefore, the use of a clinical effectiveness quality initiative and cerebral oximetry in all cardiac surgery, with the SAS system for off-pump surgery, should be advocated.
Acute Insulin Resistance in Myocardial Ischemia: Causes and Consequences
Authors: Smit Johannes W. A. , Romijn Johannes A.
Published: June 2007

Diabetes mellitus is associated with increased risk for cardiovascular mortality because of multiple pathophysiologic mechanisms. Acute stress-induced hyper-glycemia during acute myocardial infarction has gained much attention, as blood glucose levels seem to be an independent risk factor for acute myocardial infarction–related death. Clinical studies that identify stress-induced hyperglycemia as a risk factor are reviewed and its causes are discussed. They can be summarized as the consequence of acute insulin resistance, which in its turn is caused by stress hormones and by proinflammatory cytokines. Hyperglycemia causes the release of proinflammatory cytokines, the induction of reactive radicals, alterations in cardiovascular substrate metabolism, and propagation of coagulation and apoptosis. These all have harmful effects during and after acute myocardial infarction. Recommendations are for strict glycemic control in hyperglycemic patients with acute myocar-dial infarction, although the target glucose level is still a subject of debate.
Genetics of Postoperative Complications Following Thoracic Surgery
Authors: Shaw Andrew
Published: June 2007

The field of complex trait-gene interaction research has expanded exponentially in recent years, and new insights into the ways patients respond to surgical stimuli have arisen from this body of work. From a physiological systems perspective, thoracic surgical procedures (thoracotomy in particular) represent a massive input stimulus, and it is, therefore, not surprising that approximately 30% of these patients experience an adverse postoperative event. The best risk prediction models have typically explained about 60% to 70% of the risk, leaving a large residual component unaccounted for. It is quite possible that there is a genetic (heritable) component to this residual risk. This article explores some of the concepts underlying gene-disease interactions, the preliminary work that has been done to date in this area, and finally discusses some of the more important methodological issues involved in complex trait association study design.
Opioid Analgesia in Neonates Following Cardiac Surgery
Authors: Hammer Gregory B. , Golianu Brenda
Published: June 2007

Pain in the newborn is complex, involving a variety of receptors and mechanisms within the developing nervous system. When pain is generated, a series of sequential neurobiologic changes occur within the central nervous system. If pain is prolonged or repetitive, the developing nervous system could be permanently modified, with altered processing at spinal and supraspinal levels. In addition, pain is associated with a number of adverse physiologic responses that include alterations in circulatory (tachycardia, hypertension, vasoconstriction), metabolic (increased catabolism), immunologic (impaired immune response), and hemostatic (platelet activation) systems. This “stress response” associated with cardiac surgery in neonates could be profound and is associated with increased morbidity and mortality. Neonates undergoing cardiac operations are exposed to extensive tissue damage related to surgery and additional painful stimulation related to endotracheal and thoracostomy tubes that may remain in place for variable periods of time following surgery. In addition, postoperatively neonates endure repeated procedural pain from suctioning of endotracheal tubes, placement of vascular catheters, and manipulation of wounds (eg, sternal closure) and dressings. The treatment and/or prevention of pain are widely considered necessary for humanitarian and physiologic reasons. Improved clinical and developmental outcomes underscore the importance of providing adequate analgesia for newborns who undergo major surgery, mechanical ventilation, and related procedures in the intensive care unit. This article reviews published information regarding opioid administration and associated issues of tolerance and abstinence syndromes (withdrawal) in neonates with an emphasis on those having undergone cardiac surgery.
The Postoperative Care of Adult Patients Exposed to Deep Hypothermic Circulatory Arrest
Authors: Stier Gary R. , Verde Edward W.
Published: June 2007

Deep hypothermic circulatory arrest with cardiopulmonary bypass is indicated for complex surgical operations in adult patients involving the aortic arch, thoracoabdominal aorta, cerebral vasculature, and tumors extending into the vena cava and heart. Understanding the principles of ischemic-reperfusion injury and the effects of hypothermia in attenuating this process is fundamental to the delivery of effective postoperative care. Neurologic injury is the most troublesome adverse effect after the use of deep hypothermic circulatory arrest and cardiopulmonary bypass, presenting as either a transient neurologic deficit (5.9% to 28.1%) or an irreversible neurologic injury (1.8% to 13.6%). In patients with neurological injury, early postoperative mortality is markedly increased (18.2%), and for those patients that survive, long-term cognitive disability is still evident 6 months later. Early postoperative support of organ function, along with timely diagnosis and treatment of organ injury, is essential in minimizing perioperative morbidity, particularly neurologic morbidity. Meticulous management of fluids, maintaining stable cardiovascular hemodynamics with particular attention to systolic blood pressure, optimizing oxygen delivery, limiting ventilatorassociated lung injury, intensive insulin therapy for control of blood glucose levels, and avoidance of hyperthermia are essential in limiting organ injury and reducing perioperative morbidity and mortality.
From Micro to Meso: Critical Steps in Conceptualizing and Conducting Multilevel Research
Authors: Klein Katherine J. , Kozlowski Steve W. J.
Published: June 2007

Although interest in multilevel organizational theory, research, and methods has been on the rise in recent years, vigorous debates in the literature regarding appropriate ways to conceptualize and measure multilevel constructs, justify aggregation, and analyze multilevel models have contributed to confusion. New investigators interested in testing multilevel theory are intrigued, but wary. The goal of this article is to cut through the confusion, identifying the critical choices and issues a researcher may confront as he or she shifts from a single level to a multilevel perspective. The authors address four primary choices—construct and measurement issues, model specification, research design and sampling, and data analyses— describing critical steps in conceptualizing and conducting multilevel research.
Multidimensional Constructs in Organizational Behavior Research: An Integrative Analytical Framework
Authors: Edwards Jeffrey R.
Published: June 2007

Multidimensional constructs are widely used to represent several distinct dimensions as a single theoretical concept. The utility of multidimensional constructs relative to their dimensions has generated considerable debate, and this debate creates a dilemma for researchers who want the breadth and comprehensiveness of multidimensional constructs and the precision and clarity of their dimensions. To address this dilemma, this article presents an integrative analytical framework that incorporates multidimensional constructs and their dimensions, using structural equation modeling with latent variables. This framework permits the study of broad questions regarding multidimensional constructs along with specific questions concerning the dimensions of these constructs. The framework also provides tests of issues underlying the multidimensional construct debate, thereby allowing researchers to address these issues on a study-by-study basis. The framework is illustrated using data from studies of the effects of personality on responses to conflict and the effects of work attitudes on employee adaptation.
Testing Interaction Effects in LISREL: Examination and Illustration of Available Procedures
Authors: Cortina Jose M. , Chen Gilad , Dunlap William P.
Published: June 2007

The concomitant proliferation of causal modeling and hypotheses of multiplicative effects has brought about a tremendous need for procedures that allow the testing of moderated structural equation models (MSEMs). The seminal work of Kenny and Judd and Hayduk has been drawn on by several authors in the past 10 years, thus producing procedures that allow for such tests. Yet, utilization of MSEMs in empirical research has been quite rare. The purposes of this article are twofold. First, the authors discuss general issues with respect to multivariate normality, indicators of latent products, the nature of latent products, and identification problems in MSEM. Second, they review and illustrate techniques that are available for the testing of interaction effects in structural equation models.
Measuring Impression Management in Organizations: A Scale Development Based on the Jones and Pittman Taxonomy
Authors: Bolino Mark C. , Turnley William H.
Published: June 2007

Five studies were conducted to develop a measure of employee impression management behaviors based on the taxonomy proposed by Jones and Pittman. In Study 1, 44 items were given to student judges to verify the content validity of the items. In Study 2, the scale was administered to a sample of professionals and exploratory factor analysis was conducted. Based on the results, revisions to the scale were made. In Study 3, the revised scale was administered to a group of managers and exploratory factor analysis was again performed. In Study 4, the final version of the scale was administered to another sample of professionals and confirmatory factor analysis was performed. Finally, in Study 5, the convergent and discriminant validity of the scale was assessed using a sample of management students. The results support the taxonomy presented by Jones and Pittman. Suggestions for future research using the new measure are discussed.
National Values and Tipping Customs: A Replication and Extension
Authors: Lynn Michael , Lynn Ann
Published: June 2007

This study examines the relationships between national values and tipping customs in a sample of 45 nations. The results of the study conceptually replicate and extend the work of Lynn, Zinkhan and Harris (1993) by demonstrating for the first time that national values predict international differences in customary tip sizes as well as international differences in the number of tipped professions. They also indicate that customary tip sizes for different service professions are related to different values, suggesting that the important functions of tipping vary across service contexts.
The Investment Opportunity Set and the Long-Term Debt Decision of U.S. Lodging Firms
Authors: Dalbor Michael C. , Upneja Arun
Published: June 2007

This article investigates, in further detail, a previously researched positive relationship between long-term debt and growth opportunities in the U.S. lodging industry. In addition to utilizing variables related to the three major theories of capital structure, the authors use alternative growth opportunity measures in an attempt to confirm previous findings in the hospitality literature. The results indicate that certain growth opportunity proxies do a better job of explaining the long-term debt choice for U.S. lodging firms. This research could be used to reexamine the long-term debt decision and growth opportunities in other sectors of the hospitality industry.
Use of a Urine Color Chart to Monitor Hydration Status in Nursing Home Residents
Authors: Mentes Janet C. , Wakefield Bonnie , Culp Kennith
Published: June 2007

To determine whether urine color, as measured by a color chart, might be a valid indicator of hydration status in frail nursing home residents, this study tested the associations between urine color and urine specific gravity. This is a descriptive correlational study set in seven nursing homes in eastern Iowa. Ninety-eight nursing home residents 65 years of age participated. Exclusion criteria for the study included: unstable congestive heart failure or diabetes, documented renal disease, hyponatremia (serum sodium < 135 meq/L), terminal illness, acutely confused/delirious or urinary tract infection at baseline, and gastrostomy-tube dependence. Weekly urine specimens were collected. Ucol was measured first, using a urine color chart. Usg was determined using the Chemstrip Mini UA Urine Analyzer. Week-by-week Spearman rank order correlations between urine color and specific gravity for the total sample (n = 98) ranged from rs = 0.3 - 0.7, p < .01; the PROC mixed model was significant, p < .01. In subgroup analyses (n = 78), all females (rs = 0.67, p = .01) and both males (rs = 0.53, p = .01) and females (rs = 0.72, p = .01) with adequate renal function (Cockcroft-Gault estimated creatinine clearance [CrCl] values of 50 ml/min) had significant associations between average urine color and average Usg. Females with mild renal impairment (CrCl between 30 and 50 ml/min) also had significant associations between Ucol and Usg (rs = .64, p < .01). Ucol averaged over several individual readings offers another tool in assessing hydration status in Caucasian nursing home residents with ade quate renal function measures by estimated CrCl values.
The Hypo-Osmolality of Pregnancy Does Not Alter Baroreceptor Responses to Acute Changes in Osmolality
Authors: Hines Tina , Veeh Jessica , Grimes Dawn
Published: June 2007

Reducing extracellular osmolality by 10-12 mOsm/L reduces baroreceptor firing in vitro in tissues from male rats. Pregnancy is associated with a similar reduction in plasma osmolality (pOsm) as well as with alterations in baroreceptor firing and reduced baroreceptor reflex activity. Mechanisms for reduced baroreflex activity are not yet understood, but they have important implications for maintenance of cardiovascular homeostasis in the pregnant female. Thus, this study was designed to test whether changes in plasma osmolality alter baroreceptor discharge during pregnancy. Late-gestation pregnant and virgin control rats were anesthetized, femoral vessels were cannulated for measurement of arterial pressure and drug infusion, and the aortic depressor nerve, containing baroreceptor afferents, was isolated and prepared for recording. Plasma osmolality was measured before and 30 min after graded intraperitoneal injections of NaCl (50-1500 mOsm/L). Arterial pressure, heart rate, and aortic depressor nerve activity (ADNA) were measured continuously before and after injections. A 50 mOsm/L NaCl injection significantly decreased pOsm but did not alter ADNA in either group. Likewise, 1200 mOsm/L NaCl injections significantly increased pOsm and had no effect on ADNA in either group. The 1500 mOsm salt load significantly increased pOsm and ADNA in pregnant rats, and in virgin animals, it increased pOsm but evoked a paradoxical decrease in ADNA. The authors’ studies indicate that pOsm has minimal effects on baroreceptor activity, which are not significantly different during gestation. Their findings suggest that in vitro data from male rats indicating a correlation between pOsm and baroreceptor discharge are not applicable in anesthetized intact female animals.
Stress Management for African American Women With Elevated Blood Pressure: A Pilot Study
Authors: Webb Mary , Beckstead Jason , Meininger Janet , Robinson Sabrina
Published: June 2007

This article reports the results of a pilot study testing the effects of two stress management interventions on blood pressure (BP) and stress-related variables in employed African American women. Thirty-three women with mean age 44.8 ± 7.6 years were randomly assigned to a cognitive mediation group (n = 10), a relaxation group (n = 12), or a delayed treatment control group (n = 11). The participants in the two stress management groups participated in a 10-week intervention; the delayed treatment control group received BP monitoring during the 10-week period. Measures included BP, the State-Trait Anger Expression Inventory, Personal Strain, and Coping Resources. Although no significant Group × Time effects were found in BP, anger, or personal strain, several of the outcome measures appear to be sensitive and showed cell means in the hypothesized direction. Further study of the effects of stress management interventions on BP and stress, with a larger sample, is warranted.
Marketing to the visiting friends and relatives segment: An international analysis
Authors: Morrison Alastair , Woods Barbara , Pearce Philip , Moscardo Gianna , Sung Heidi H.
Published: June 2007

This paper provides a unique analysis of the visiting friends and relatives (VFR) market across four different countries. It highlights that this market, although substantial at both the domestic and international levels, is poorly understood and that certain common assumptions made by travel marketers about VFRs are inaccurate. Marketing directors’ attitudes toward the VFR market are measured in a special study of VFR marketing in Australia, Canada, New Zealand and the USA. Successful cases of VFR marketing in these countries are described.
Tourist shopping in transit: The case of BAA plc
Authors: Hobson J. S. Perry
Published: June 2007

This case study examines the development of travel retailing within the UK’s major airports between 1987 and 1999. The paper reviews the strategic marketing and business developments undertaken by BAA plc since privatisation as it has developed its retailing division. The development of retailing concepts in its airports, joint partnerships at non-airport sites and acquisitions are examined. The impact of the abolition of intra-European Union tax and duty-free sales from July 1999 is looked at, and the future of BAA’s retailing strategies is considered.
A comparative case study analysis of two UK marketing consortia: Drifters and Waterways
Authors: Oakley Ben , Fyall Alan
Published: June 2007

Marketing consortia represent an increasingly popular means by which tourism organisations are able to accomplish collective and organisational marketing goals. However, few case studies have been published that address marketing issues in inter-organisational collaborative initiatives generally, and more specifically the reconciliation of intra-sector competition within marketing consortia. Within the context of inland waterway hire-boat holidays in Britain this paper explores the collaborative behaviour of two contemporary marketing consortia: the Inland Waterways consortium and the Drifters consortium. The paper compares and contrasts their respective approaches to the marketing of inland waterway hire-boat holidays in Britain and the means by which they attempt to reconcile intra-sector competition. Information derived for the paper originates from two primary face-to-face interviews and two previous studies published by the authors.1 The paper concludes by discussing the basic principles of collaboration which arguably should be met in order to maximise mutual gain from membership of marketing consortia.
A test of a theoretical model of consumer travel behaviour: German consumers’ perception of Northern Ireland as a tourist destination
Authors: Lennon Ron , Weber J. Michael , Henson James
Published: June 2007

Data for this study were collected from German travel consumers at the ITB Travel Trade Fair in Berlin, Germany. The subsequent study empirically tested the influences of information source and travel experience on the perception of Northern Ireland as a safe place. In addition, the influences of information source and travel experience were tested in relation to the perception of Northern Ireland as a travel destination. Some sources of information about Northern Ireland were found to have a positive influence on perceptions, while one (direct mail) had a negative influence on the perception of Northern Ireland as a safe place. The only aspect of travel experience that had a significant influence on the perceptions of travel consumers was whether respondents had visited Northern Ireland before.

The eventual premise that was examined was the effect that these previous two perceptions might have on a German travel consumer’s behavioural intentions toward visiting Northern Ireland in the future. The model developed by Lennon et al. in 1999 depicts these relationships. The study supported the influence of the travel consumers’ perceptions of Northern Ireland as a safe place and as a German travel destination on future behavioural intentions to visit Northern Ireland.
Dazed and confused? An exploratory study of the image of Brazil as a travel destination
Authors: Rezende-Parker Aline M. , Morrison Alastair M. , Ismail Joseph A.
Published: June 2007

The tourism industry in Brazil has been growing sharply in the past few years. Among its visitors, US citizens are one of the most important and attractive markets for the Brazilian tourism industry. It is believed, however, that most Americans still know little about Brazil and what it has to offer. This study had three objectives: determine the images that American citizens interested in travel and tourism have of Brazil as a travel destination, determine if they differentiate Brazil from neighbouring Hispanic countries and group them according to similar images of Brazil. Online discussion groups on travel and tourism were used to obtain a sample of this population. The results indicated that ‘natural attractions/interest’ and ‘vacation atmosphere/exoticness’ were the two most important images of Brazil among the respondents. The results also indicated that respondents were unable to differentiate Brazil from Hispanic countries.
Individualism/collectivism as a moderating factor to the self-image congruity concept
Authors: Litvin Stephen W. , Kar Goh Hwai
Published: June 2007

Self-image congruity, the relationship between one’s self-image and one’s image of a product or service, is a widely accepted consumer behaviour theory lately finding currency in tourism literature. For tourism, as a global industry involving international tourists from varied cultural backgrounds, it is important to explore how the theory holds across a broad spectrum of cultures. To test the concept’s cross-cultural applicability, an exit survey which overlaid the concept of self-image congruity with Geert Hofstede’s cross-cultural dimension of individualism/collectivism was administered to vacation travellers from multiple cultures as they departed Singapore airport. The results affirmed the applicability of the concept of self-image congruity for tourism research and, extending this understanding, suggested that the concept enjoyed enhanced robustness when considered in conjunction with the cultural moderating variable of individualism/collectivism.
Community tourism: A lesson from Kenya’s coastal region
Authors: Kibicho Wanjohi
Published: June 2007

Tourism in developing countries is a crucial agent for development and indeed an ideal economic alternative to traditional sectors. But as destinations exploit their tourism potentials, they have to realise that the involvement of the tourist host communities in tourism development projects is vital. This paper evaluates the situation in Kenya’s coastal region. It lays emphasis on how the local people are being involved in tourism development in the region, and how such integration can be used as a means to win the obviously needed local community’s support for the industry. It is based on data collected between the period March to June 1998 and December 1999 to April 2000.