bluuebunny/crossref_metadata_2025 huggingface dataset:
Complications of Major Aortic and Lower Extremity Vascular Surgery
Authors: Ghansah J. Nana , Murphy J. Thomas
Published: March 2006

Atheromatous disease and invasive intervention of the aortoiliac and distal arteries are common. Morbidity and mortality have been reduced through understanding and management of patient risk factors. Complications of this form of treatment affect all organ systems; mortality is most frequently caused by a cardiovascular complication (eg, myocardial infarction). Infection, leading to aortoenteric fistula is a dreaded complication, and paraplegia, though rare, is a devastating outcome. Multiorgan failure and death may result from a systemic inflammatory response syndrome. Vascular surgery for infrainguinal disease also has a significant cardiovascular complication rate. Resulting complications may affect all organs; loss of an extremity may occur. The first part of this article reviews perioperative and postoperative complications of open aortic repair and lower-extremity revascularization and addresses the issue of regional anesthesia for major vascular surgery. The second part reviews endovascular aortic repair (EVAR). EVAR is a new intervention that combines surgery and radiology. Complications of EVAR are similar to open repair, but early results suggest they may be less frequent. New technology leads to new complications; endoleaks, migration of the endoprosthesis, and surgical conversion are unique to EVAR. The benefits of EVAR may be less blood loss, shorter hospitalization, and less cardiovascular stress; the risks may be aneurysm recurrence, prolonged surveillance and repeated secondary procedures. The development of EVAR, the complications, and the anesthesia-related concerns of EVAR, including its use in management of acute abdominal aortic aneurysm are reviewed.
Applied Neuromonitoring in Cardiac Surgery: Patient Specific Management
Authors: Saidi Nousheh , Murkin John M.
Published: March 2006

Various studies have demonstrated that over 50% of patients presenting for coronary revascularization surgery have evidence of extracranial or intracranial atherosclerotic disease. Although evidence is compelling that cerebral emboli are a major cause of perioperative central nervous system (CNS) morbidity in such patients, it is also apparent that alterations in cerebral perfusion pressure and blood flow can profoundly influence the extent of injury after an embolic insult. In this context, the recent studies demonstrating improved CNS outcomes with applied neuromonitoring in cardiac surgical patients can be understood as reflecting the optimization of CNS perfusion characteristics with potential amelioration of microembolic injury. This review critically evaluates and discusses the relevant characteristics of applied neuromonitoring techniques, including bispectral index (BIS), transcranial Doppler (TCD), and near infrared reflectance spectroscopy (NIRS) in the context of patients undergoing cardiac surgical procedures. Recent outcomes data regarding CNS and related morbidity and the influence of neuromonitoring in these groups are evaluated.
The Safety and Efficacy of “Bloodless” Cardiac Surgery
Authors: Shander Aryeh , Moskowitz David , Rijhwani Tanuja S.
Published: March 2006

Nearly 20% of blood transfusions in the United States are associated with cardiac surgery. Despite the many blood conservation techniques that are available, safe, and efficacious for patients undergoing cardiac surgery, many of these operations continue to be associated with significant amounts of blood transfusion. Although surgical bleeding after cardiopulmonary bypass is a common problem as reflected by the substantial use of blood products, it is the individual physician and institutional behavior that have been identified as reasons for transfusion and not necessarily patient comorbidity or blood loss. Transfusion rates in cardiac surgery remain high despite major advances in perioperative blood conservation, with large variations among individual centers. The adoption of available blood conservation techniques, either alone or in combination in patients undergoing cardiac surgery, could result in an estimated 75% reduction of unnecessary transfusions. The success of previously reported blood conservations programs in cardiac surgery should call for a reevaluation of allogeneic transfusion practices in patients undergoing cardiac surgery. By applying the numerous reported blood conservation strategies for the management of patients presenting for cardiac surgery, we can preserve our dwindling blood resources and help alleviate some of the direct costs of blood as well as the indirect costs of treating noninfectious and infectious complications of transfusion.
Evidence-Based Renal Protection in Cardiac Surgery
Authors: Stafford-Smith Mark
Published: March 2006

Acute renal dysfunction is a common serious complication of cardiac surgery. Although a diversity of mechanisms exist by which the kidney can be damaged during cardiac surgery, atheroembolism, ischemia–reperfusion, and inflammation are believed to be primary contributors to perioperative renal insult. In addition, the high metabolic demands of active tubular reabsorption and the oxygen diffusion shunt characteristic of renal circulation make the kidney particularly vulnerable to ischemic injury. Remote effects of acute renal injury likely contribute to the strong association of this condition with other major postoperative morbidities and mortality and justify the search for renoprotective agents, even when dialysis is never required. Nonpharmacologic preventive strategies include procedure planning that is based on risk stratification, avoidance of nephrotoxins, and meticulous perioperative clinical care, including optimizing intravascular volume and attention to modifiable risk factors such as minimizing hemodilution. Although numerous pharmacologic interventions to prevent or treat acute renal injury have shown promise in animal models, randomized placebo-controlled clinical trials that have looked at measures of significant adverse outcomes such as death and dialysis have not confirmed a benefit.
Atrial Fibrillation After Cardiac Surgery: An Evidence-Based Approach to Prevention
Authors: Kailasam Rajagopal , Palin Christopher A. , Hogue Charles W.
Published: March 2006

A number of advances in surgical and anesthetic techniques have reduced the risk for patients undergoing cardiac surgery. However, postoperative atrial fibrillation remains common, with an incidence ranging between 25% and 40%. It is associated with an increased incidence of congestive heart failure, renal insufficiency, and stroke that prolongs hospitalization and increases rates of readmission after discharge. Consequently, there has been great interest in strategies to prevent this arrhythmia. When both safety and efficacy are considered, the available evidence to date suggests that only ßblockers can be recommended for the prevention of atrial fibrillation after cardiac surgery. Other treatments might be considered on an individual basis after careful consideration of the patient's potential for side effects.
Regional Anesthesia in Cardiac Surgery: A Friend or A Foe?
Authors: Djaiani George , Fedorko Ludwik , Beattie W. Scott
Published: March 2006

Escalating costs and change in the profile of patients presenting for cardiac surgery requires modification of perioperative management strategies. Regional anesthesia has played an integral part of many fast-track anesthesia protocols across North America and Europe. This review suggests that for patients undergoing coronary artery bypass graft surgery, the risk-to-benefit ratio is in favor of epidural and spinal anesthesia, provided there are no specific contraindications and the guidelines for the use of regional techniques in cardiac surgery are followed. Patients managed with regional techniques seem to benefit from superior postoperative analgesia, shorter postoperative ventilation, reduced incidence of supraventricular arrhythmia, and lower rates of perioperative myocardial infarction. The results of this analysis suggest that for each episode of neurologic complication, 20 myocardial infarctions and 76 episodes of atrial fibrillation would be prevented, thus, we would consider the regional anesthesia and analgesia to be an effective strategy that improves perioperative morbidity. However, other treatment modalities such as the addition of calcium channel blockers, aspirin, and beating heart surgery, are also suggested to be beneficial in cardiac surgical patients and may impose less risk than the use of regional techniques. We believe that the results presented in this review are encouraging enough to permit continued investigation. A prospective, randomized, controlled multicenter trial needs to be adequately powered to answer important clinical questions and allow for a long-term follow-up.
Off Pump Coronary Artery Bypass Graft Surgery Versus Conventional Coronary Artery Bypass Graft Surgery: A Systematic Review of the Literature
Authors: Bainbridge Daniel , Martin Janet , Cheng Davy
Published: March 2006

The recent development of off-pump coronary artery bypass (OPCAB) graft surgical techniques has led to numerous observational and several randomized trials that have investigated outcomes compared with the current gold standard of conventional on-pump coronary bypass (CCAB) graft surgery. This systematic review assesses the current randomized trials that compare OPCAB and CCAB. Numerous end points were investigated, including mortality, stroke, myocardial infarction, atrial fibrillation, blood transfusions, wound infections, and renal failure. In addition to these important outcomes, resource utilization markers were also examined such as hospital length of stay, intensive care unit length of stay, and duration of intubation/ventilation. Finally, when level I evidence from randomized trials was unavailable, level II evidence was examined. This was done for subgroup analysis, where currently no randomized trials exist, looking at OPCAB in high-risk patients. Recommendations were made as to who should receive OPCAB and the potential benefits in this patient population.
Building and Supporting Sustainable Improvement in Cardiac Surgery: The Northern New England Experience
Authors: Nugent William C.
Published: March 2006

The Northern New England Cardiovascular Disease Study Group (NNECDSG) was formed as a regional clinical database that would allow clinicians to track outcomes after cardiac interventions. The purpose of the NNECDSG would be to use its database and organizational structure to seek best practices and disseminate information aimed at improving results for patients undergoing cardiovascular interventions. Since 1987, this voluntary regional collaborative of clinicians, hospital administrators, and health care research personnel has tracked consecutive cardiovascular interventions performed throughout Northern New England and reported its findings to the clinicians. Collaboration between NNECDSG institutions has led to progressive refinements in the clinical database, institutional site visits, efforts to understand and standardize ideal processes of care, risk-stratification tools to aid in decision making, and most recently, tools to track and report on appropriateness of interventions based on national criteria. As a result of these efforts, mortality rates after coronary bypass graft surgery have steadily declined and the variation in mortality rates between institutions has disappeared.
Improving Outcomes of Cardiac Surgery Through Cooperative Efforts: The Northern New England Experience
Authors: Likosky Donald S. , Nugent William C. , Ross Cathy S.
Published: March 2006

Coronary artery bypass graft (CABG) surgery is an effective procedure for relieving angina. In 1987, the Health Care Financing Administration published surgeon-specific mortality rates, prompting the formation of the Northern New England Cardiovascular Disease Study Group (NNECDSG). This regional collaborative of all medical centers performing cardiovascular procedures in northern New England began collecting data concerning patient and disease characteristics and adverse outcomes in an effort to improve the care provided to their patients. An initial quality improvement effort resulted in a 24% reduction in in-hospital mortality. Subsequent efforts have involved the development and implementation of quality improvement initiatives to redesign care to reduce further a patient's risk of mortality and other morbidities. More recently, we have adopted this model to reduce a patient's risk of neurologic injury. In this study, we are intensively monitoring patients intraoperatively with transcranial Doppler and near infrared spectroscopy as well as collecting hemodynamic data, and are synchronizing this data with a video of the surgical site. The goal of the study is to identify the association between clinical strategies and the development of the precursors of neurologic injury and use a quality improvement approach to redesign care to reduce occurrence of these precursors.
Cognitive Dysfunction After Cardiac Surgery: Revisiting Etiology
Authors: Grocott Hilary P. , Homi H. Mayumi , Puskas Ferenc
Published: March 2006

Cognitive dysfunction remains a frequent complication of cardiac surgery. Despite many years of research, few preventive strategies and no definitive therapeutic options exist for the management of this troublesome clinical problem. This shortcoming may be secondary to an incomplete understanding of the pathophysiology and etiology of cognitive loss after cardiac surgery; a better understanding of the etiology is essential to finding new therapies. The etiology of cognitive dysfunction after cardiac surgery is multifactorial and includes cerebral microembolization, global cerebral hypoperfusion, systemic and cerebral inflammation, cerebral temperature perturbations, cerebral edema, and possible blood-brain barrier dysfunction, all superimposed on genetic differences in patients that may make them more susceptible to injury or unable to repair from injury once it has occurred. This review expands on these potential etiologies in detailing the evidence for their existence.
Reducing the Risk of Myocardial Revascularization: Relevance of Multimodal Brain Monitoring
Authors: Novitzky Dimitri
Published: March 2006

Perioperative neurologic events in heart surgery are the most devastating complications. Although myocardial revascularization without cardiopulmonary bypass (CPB) has reduced the incidence of cerebrovascular accidents, they still remain a reality that the cardiothoracic surgeon is unable to completely eliminate. The events leading to a neurologic complication are related to hemodynamic instability and embolization of aortic debris at the time a side-biting clamp is applied. Combined events may eventually impact the brain to varying degrees, ranging from a temporary confusional state to a fullblown stroke from which meaningful recovery may be impossible. This report describes the interventions necessary to maintain hemodynamic stability, the role of brain monitoring required, and how to safely achieve complete off-CPB myocardial revascularization and minimize the incidence of neurologic complications. Cardiac interventions include maintaining sinus rhythm, providing adequate blood supply to all vital organs, and avoiding induction of myocardial ischemia, which may induce supraventricular, ventricular arrhythmias, or both. These interventions depend upon an experienced surgical team (anesthesiologist, cardiologist, surgeon, and operating room and intensive care unit recovery nurses). Anticipation of myocardial ischemia may require loading the patient with antiarrhythmic drugs, and placement of intracoronary shunts and intraaortic balloon pump support. Patience from the surgeon is often required to allow time for the specific intervention to act. In addition to interventions to maintain a balance between the demand and supply of oxygen, we frequently rely on “intermittent hypotensive anesthesia” while performing the distal and proximal coronary anastomoses. Hypotension may lead to inadequate oxygen supply to the brain, so multimodal brain monitoring becomes mandatory. We use a combination of transcranial brain oximetry and electroencephalographic compressed spectral array. This combined monitoring results in a safer surgical procedure, allowing the hemodynamic interventions to be performed rationally and without interruption of the surgical procedure.
Applied Neuromonitoring and Improving CNS Outcomes
Authors: Murkin John M.
Published: March 2006

Despite an overall decrease in perioperative morbidity and mortality, evidence of some degree of central nervous system dysfunction associated with coronary artery bypass graft (CABG) surgery—with or without cardiopulmonary bypass— has steadily mounted. From preoperative studies of CABG patients, it is apparent that over 50% of patients who present for cardiac surgery have evidence of either extracranial or intracranial atherosclerotic disease. Patient-specific factors thus have a fundamental impact on the risks of a brain injury developing after CABG surgery. Cerebral embolization and/or ischemic hypoperfusion are the most likely etiologic mechanisms for perioperative brain injury associated with cardiac surgery, and these factors are closely interrelated. Various monitoring techniques can decrease risk of intraoperative cerebral embolization and hypoperfusion and are associated with improved outcomes. Ultrasound guided aortic instrumentation (epiaortic scanning) can markedly decrease atheroembolic load and risk of stroke. Unrecognized sources of microgaseous emboli, including air entrainment from surgical purse string sutures and perfusionist interventions, can be identified and reduced by transcranial Doppler monitoring. Cerebral hypoperfusion from unrecognized cerebral venous obstruction, inadequate mean arterial pressure, or from hypocapnic cerebral alkalosis can be identified by multimodality neuromonitoring using regional cerebral oxygen saturation and transcranial Doppler. Overall patient outcomes can be improved, and hospital length of stay shortened, by applied neuromonitoring techniques.
Organ Protection During Thoracoabdominal Aortic Surgery: Rationale for a Multimodality Approach
Authors: MacArthur Roderick G. , Carter Stacey A. , Coselli Joseph S. , LeMaire Scott A.
Published: March 2006

Surgical repair of thoracoabdominal aortic aneurysms (TAAAs) remains a technically challenging operation that requires a systematic approach to prevent ischemic complications and achieve excellent clinical outcomes. Techniques for organ protection have evolved substantially over the past 20 years. This review describes our current multimodality approach to organ protection during TAAA repair.
A Systematic Approach to the Understanding and Redesigning of Cardiopulmonary Bypass
Authors: Groom Robert C. ,   Cardiovascular Disease Study Group
Published: March 2006

Cardiopulmonary bypass (CPB) is a highly complex process. We developed a system to capture and study detailed information during cardiac surgery that serves as a framework for understanding variation that occurs during CPB. The system allows the surgical team to link unwanted variation (ie, hypotension) and unwanted events (ie, the production of microemboli) to the processes of care. A more thorough understanding of embolic activity and hemodynamic aberrations, precursors to both stroke and subtle neurologic injury, that occur during CPB, will allow the surgical team to identify high leverage, modifiable aspects of care and abate these precursors to patient injury. Multimodality simultaneous monitoring and recording of physiologic parameters, emboli in the CPB circuit and in the middle cerebral arteries, and cerebral NIRS during surgery was carried out in patients undergoing open heart surgery with CPB. A system was designed that captures physiologic data from the patient monitors and the heart-lung machine at 20-second intervals and time synchronizes all measures with a video recording of the surgical procedure. Emboli counts count in the CPB circuit and right and left middle cerebral arteries were continuously recorded. Video recordings depicting various surgical and perfusion techniques with associated embolic activity were provided to the surgical team. Wide variation in embolic counts, cerebral blood flow velocity, and physiologic parameters were observed. Periods of embolic activity and cerebral desaturation could be related to surgical and CPB processes of care. We have identified increased emboli counts in the CPB circuit and in the middle cerebral arteries related to the method of venous drainage, manipulation of the aorta, and anastomotic techniques. se of this model provides the surgical team detailed information about these precursors to neurologic injury. This system provides a systematic approach to the understanding and redesigning of CPB.
3-D Imaging for Aortic Plaque Assessment
Authors: Bainbridge Daniel
Published: March 2006

Stroke and neurologic dysfunction continue to complicate cardiac surgery despite improvements in cardiopulmonary bypass. Intra-aortic plaque disrupted during aortic manipulation is a known risk factor contributing to neurologic complications; therefore, avoidance of these plaques during aortic manipulation is important. Intraoperative epiaortic echocardiography, with its high sensitivity and specificity, has become the modality of choice for detecting plaque within the aorta during cardiac surgery and is superior to either transesophageal echocardiography or aortic palpation for this purpose. Recently the matrix x4 three-dimensional (3D) ultrasound probe (Philps Medical Systems) was introduced allowing both real time 3D imaging and electrocardiography-gated “full volume” imaging, which essentially acquires a larger image but requires 8 cardiac cycles. Modification of our routine scanning technique was required, employing a saline (about 30 mL) filled sterile sheath secured with a sterile elastic band (creating a saline pocket). There appears little difference in the sensitivity of either 2D or 3D imaging to detect plaque within the aorta. We found that live 3D was superior to 2D imaging in identifying, localizing, and defining the true extent of plaque in the aorta.
Myocardial Metabolism and Improved OutcomesAfter High Risk Heart Surgery
Authors: Keith Mary , Errett Lee
Published: March 2006

The healthy heart relies primarily upon the oxidation of fatty acids for energy, with the remaining coming from the oxidation of glucose and lactate. Changes in energy requirements are met by altering the balance of fuels depending upon the hormonal milieu as well as upon the availability of oxygen and substrates. The use of carbohydrates for fuel is metabolically more efficient and may improve the coupling between glycolysis and pyruvate oxidation. Therefore, promoting a shift in metabolic fuel substrate use during times of reduced oxygen availability may represent a cardioprotective strategy. Subsequently, there has been interest in pharmacologic strategies such insulin or drugs like ranolazine and dichloroacetate that stimulate carbohydrate oxidation either by enhancing oxidation at the pyruvate dehydrogenase complex or by limiting fatty acid oxidation. There is evidence that nutrients may also be able to stimulate carbohydrate oxidation. Previous studies by our group suggest that a combination of nutrients (carnitine, coenzyme Q10, and taurine) may work together, resulting in pleiotropic cardioprotective effects. Our current studies are investigating the potential of nutrients as both a preventative and adjunctive treatment before and after an ischemic event. These investigations will determine the role of nutritional supplementation in the care of patients with ischemic injury.
Chronic Thromboembolic Pulmonary Hypertension and Pulmonary Thromboendarterectomy
Authors: Manecke Gerard R. , Wilson William C. , Auger William R. , Jamieson Stuart W.
Published: March 2006

Chronic thromboembolic pulmonary hypertension results from incomplete resolution of a pulmonary embolus or from recurrent pulmonary emboli. Its incidence is underappreciated, and it is currently an undertreated phenomenon. Pulmonary thromboendarterectomy is currently the safest and most effective treatment for this condition. The surgery involves midline sternotomy, profound hypothermic circulatory arrest, and complete endarterectomy of the pulmonary vascular tree. Success depends on effective coordination of multiple medical teams, including pulmonary medicine, anesthesiology, and surgery. This review, based on the past 30 years of experience at University of California San Diego Medical Center, includes information about the clinical history, diagnostic workup, anesthesia, surgical approach, and postoperative care. Outcome data are discussed, as are avenues for future research.
Anesthesia for Lung Transplantation
Authors: Miranda Allen , Zink Robert , McSweeney Mary
Published: March 2006

Lung transplantation is the only therapeutic option for more than 3,000 individuals in the United States with end-stage lung disease. Innovations in anesthetic and surgical techniques have expanded the indications for lung transplantation. Presently, the major limiting factor in the number of lung transplantations that are performed is the availability of suitable donor organs. Lung transplantation includes a number of surgical procedures, including single-lung, double-lung, bilateral-sequential-single-lung, heart-lung, and lobar transplantation. Patients undergoing lung transplantation present a variety of challenges to the anesthesia team. Critical periods include induction of anesthesia, initiation of positive pressure ventilation, establishment and maintenance of one-lung ventilation, pulmonary artery clamping, pulmonary artery unclamping, and reperfusion of the transplanted lung. Pharmacologic advances have been an important factor in the continued development and success of lung transplantation. Newer immunosuppressive agents have improved the prevention and management of post-transplant rejection. Selective pulmonary vasodilators that are administered via inhalation affect the anesthetic management during the surgical procedure. Technologic advances in monitoring have also been valuable in lung transplantation. Transesophageal echocardiography is commonly used to evaluate intraoperative ventricular function. Continuous cardiac output, mixed venous oxygen saturation, continuous arterial blood gas monitoring, and the bispectral index have also been used to monitor the patient during lung transplantation. Anesthetic management of lung transplantation requires a thorough understanding of end-stage lung disease and pharmacologic and technical considerations that may not be applicable in any other part of anesthetic practice.
One-Lung Anesthesia Update
Authors: Mirzabeigi Edwin , Johnson Calvin , Ternian Alen
Published: March 2006

One-lung ventilation is used during a variety of cardiac, thoracic, and major vascular procedures. Endobronchial tubes, bronchial blockers, and occasionally, single-lumen tubes are used to isolate the lungs. Patients with difficult airways and pediatric patients provide special challenges for lung isolation. Finally, intraoperative hypoxia and hypercarbia in patients with intrinsic lung disease frequently complicate one-lung anesthesia. The concepts and controversies in lung isolation techniques are discussed.
Management of Thoracic Aneurysm
Authors: Makkad Benu , Pilling Soheyla
Published: March 2006

A review of the literature on the management of thoracic aneurysm is presented. These patients have various comorbid conditions and need thorough work-ups. Aneurysms can be classified according to shapes and locations. Various methods to maintain hemodynamic stability with adequate endorgan perfusion are presented. The success of the operation depends upon preoperative anticipation and preparation for adequate organ perfusion and hemodynamic stability along with good communication between the anesthesiologist and the surgical team.
Anesthetic Implications for Patients with Rate-Responsive Pacemakers
Authors: Anand Neil K. , Maguire David P.
Published: March 2006

One hundred thousand adults and children in the United States receive pacemakers each year, of which 85% are rateresponsive pacemakers (RRPs). Recent advances in the fields of computer programming and computer chip technology have led to the myriad development of RRPs, which contain sensors that automatically adjust the pacing rate to match the physiologic changes that occur during physical exertion. Because patients with RRPs may experience heart rate changes in the operating room due to “normal” sensor function, anesthesiologists must be aware of the new developments in RRP sensor technology to properly manage these patients. Increases in respiratory rate and tidal volume as well as the use of electrocautery have been reported to accelerate the paced rate of pacemakers with minute ventilation sensors. Likewise, patient movement and saws that produce vibrations can accelerate the paced rate of patients with piezoelectric crystal sensors. This paper discusses the history of pacemaker development, reviews the currently used RRP sensors, and recommends procedures for the perioperative management of these patients. Knowledge of sensor type and factors that stimulate them will help the anesthesiologist understand the cause of these changes so that he will be able to manage clinically significant hemodynamic changes due to RRP sensor activation.
Using Cardiovascular and Pulmonary Simulation to Teach Undergraduate Medical Students: Cases from Two Schools
Authors: Goodrow Michael S. , Rosen Kathleen R. , Wood JoAnn
Published: March 2006

Simulation is becoming more widespread in undergraduate medical education, expanding well beyond its original application to anesthesiology. This heightened interest in simulation is being driven by advances in learning theory as well as technology developments. However, introducing simulation into a medical education curriculum presents significant challenges. This article describes the simulation initiatives at two medical schools. Both are state schools with similar enrollments; however, their approaches to developing and maintaining a simulation program differ. Regardless of these differences, both institutions have developed a variety of applications within the curriculum. The cases and applications that they have developed should be applicable to many medical schools.
Simulation Devices in Cardiothoracic and Vascular Anesthesia
Authors: Eason Martin P.
Published: March 2006

The subspecialty of cardiothoracic and vascular anesthesia is becoming increasingly complex. Trainees must learn to manage difficult cases and be skilled in performing a variety of procedures. With work hour limitations and societal pressures working to reduce learning and practice opportunities for trainees, new training modalities must be utilized. Simulation is currently being used to increase training efficiency. It allows trainees to experience uncommon clinical situations and complications, repetitive practice opportunities, and can be done on a flexible schedule—all without risk to the patient. Additionally, feedback after a simulation can provide trainees with an assessment of their training progress. Many of the procedures and cases in cardiothoracic and vascular anesthesia can be simulated. Current devices can simulate bronchoscopy, vessel cannulation, complex case management, and cardiopulmonary bypass. They vary from the simple to the complex and from inexpensive homemade wooden devices to high-end computer-controlled virtual reality simulators. Although not all these simulators have been validated as to their educational efficacy, they offer a new avenue to improve training efficacy and efficiency. More research needs to be done to validate these devices and assess their role in anesthesia training.
Simulation in Cardiology and Cardiothoracic and Vascular Surgery
Authors: Lake Carol L.
Published: March 2006

Cardiologists and cardiac surgeons are rapidly embracing the use of realistic patient simulators and virtual reality devices to allow mastery of complex techniques, planning of complicated procedures, crisis management of infrequently seen diseases and complications, and development of medical team work. Simulation can certainly be used for these purposes in surgical education but provides only the “tip of the iceberg” of the knowledge needed by the competent cardiothoracic, vascular, or general surgeon. Is simulation really the way to learn how to perform actual surgical procedures? This review will describe available surgical simulation technology, and define some of the problems to be solved for validation and general acceptance.
Effects of Endotracheal Tube Suctioning on Arterial Oxygen Tension and Heart Rate Variability
Authors: Bourgault Annette M. , Brown C. Ann , Hains Sylvia M. J. , Parlow Joel L.
Published: March 2006

The purpose of this study was to examine the autonomic mechanisms underlying changes in heart rate (HR) and systolic blood pressure (SBP) responses to endotracheal tube (ETT) suctioning and to compare the open versus closed methods of ETT suctioning on these measures and on arterial oxygen tension. Eighteen orally intubated participants, 33 to 82 years of age (M = 60 years), were randomized for the order of suctioning method. Arterial oxygen tension (PaO 2 ) was measured before suctioning and 30 s and 5 min following suctioning. Beat-to-beat HR and arterial blood pressure data were collected for 10-min periods before and after suctioning. HR and SBP measures were analyzed before suctioning and 1 min and 5 min following suctioning. Although there were no significant effects of ETT suctioning on the autonomic mechanisms of HR modulation and no significant differences between the two methods of suctioning, ETT suctioning resulted in an increase in HR, SBP, and PaO 2 . However, there was a decrease in the parasympathetic nervous system indicator of HR variability (HRV) following open suctioning. All patients in this study maintained a PaO 2 level 80 mm Hg, which may account for our lack of significant autonomic changes. This suggests that hyperoxygenation with 100% oxygen for a minimum of 1 min (or 20 breaths), as delivered by preoxygenation modes available on most microprocessor ventilators, should be the method of choice for all hyperoxygenation procedures to avoid a decrease in PaO2 following suctioning.
Heart Rate Variability and 24-hour Minimum Heart Rate
Authors: Burr Robert L. , Motzer Sandra A. , Chen Wan , Cowan Marie J. , Shulman Robert J. , Heitkemper Margaret M.
Published: March 2006

Heart rate variability (HRV) indices based on 24-hr electrocardiograph recordings have been used in clinical research studies to assess the aggregate activity of the autonomic nervous system. Although 24-hr HRV is generally considered noninvasive, use in research protocols typically involves considerable data collection and processing expenses and substantial participant burden. The purposes of this research methods evaluation were to describe the relationships between 24-hr minimum heart rate (HR) and several 24-hr time domain HRV indices (Ln SDNN, Ln SDANN, Ln SDNNIDX, Ln RMSSD, and Logit50) across several research data sets (normal women, normal men, children enrolled in a study of recurrent abdominal pain, women with irritable bowel syndrome, sudden cardiac arrest survivors, and heart failure patients) and to explore the possibility that 24-hr minimum HR might serve as a simpler alternative or adjunct to HRV measures in some situations. The correlations of global HRV measures (e.g., Ln SDNN, Ln SDANN) with 24-hr minimum HR were consistently larger (typical r ~ -.80) than with average HR (typical r ~ -.50). In repeated measurements, change in minimum HR was also correlated with change in general HRV (typical r ~ -.60). However, modest differentiation of minimum HR and HRV measures was noted in patients taking certain classes of cardiac medications (e.g., anti-arrhythmics, beta blockers). Twenty-four-hour minimum HR is correlated with general time domain HRV measures and might be useful as a simpler proxy, surrogate, or auxiliary variable in some clinical research applications, especially those in which participants are not receiving cardiac medications.
The Association of Psychological Factors, Physical Activity, Neuropathy, and Quality of Life in Type 2 Diabetes
Authors: Chyun Deborah A. , Melkus Gail D. , Katten Deborah M. , Price Wendie J. , Davey Janice A. , Grey Neil , Heller Gary , Wackers Frans J. Th.
Published: March 2006

The objective of this study was to determine the relationship of sociodemographics; diabetes-related factors, including diabetes-related microvascular complications; cardiac risk factors; and psychological factors with quality of life (QOL). Participants enrolled at three sites in the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study were invited to participate in this ancillary study. Questionnaires assessing psychological factors were completed by participants, and the remainder of the data was obtained as part of the DIAD study. Many participants had elevated levels of anxiety (n = 91; 82%), depressive symptoms (n = 16; 14%), anger (n = 38; 34%), and hostility (n = 17; 17%). Results of multivariate analyses conducted for each of the eight domains on the Medical Outcomes Study Short Form-36 and two Diabetes Quality of Life domains demonstrated that in the majority of models (42% to 68% of the variance explained), female sex, peripheral or autonomic neuropathy, physical inactivity, higher body mass index, and the presence of depressive symptoms and anxiety were associated with poorer QOL (p = .0001). These findings demonstrate that anxiety, depressive symptoms, and neuropathy are prevalent in older adults with type 2 diabetes. In addition, potentially important correlations were demonstrated between psychological factors, neuropathy, body mass index, and physical inactivity.
Markers of Lung Disease in Exhaled Breath: Nitric Oxide
Authors: Choi JiYeon , Hoffman Leslie A. , Rodway George W. , Sethi Jigme M.
Published: March 2006

Management of airway inflammation requires proper monitoring and treatment to improve long-term outcomes. However, achieving this goal is difficult, as current methods have limitations. Although nitric oxide (NO) was first identified 200 years ago, its physiological importance was not recognized until the early 1980s. Many studies have established the role of NO as an essential messenger molecule in body systems. In addition, studies have demonstrated a significant relationship between changes in exhaled NO levels and other markers of airway inflammation. The technique used to measure NO in exhaled breath is noninvasive, reproducible, sensitive, and easy to perform. Consequently, there is growing interest in the use of exhaled NO in the management of asthma and other pulmonary conditions. The purpose of this review is to promote a basic understanding of the physiologic actions of NO, measurement techniques, and ways that research findings might translate to future application in clinical practice. Specifically, the article will review the role of exhaled NO in regard to its historical background, mechanisms of action, measurement techniques, and implications for clinical practice and research.
Cytosine Arabinoside Induces Programmed Endothelial Cell Death Through the Caspase-3 Pathway
Authors: Moore Ida M. (Ki) , Merkle Carrie J. , Miketova Petra , Salyer Renee K. , Torres Bonny J. , Schaeffer Richard C. , Montgomery David W.
Published: March 2006

The anti-cancer effects of cytosine arabinoside (ARA-C) are well known. However, effects on nonmalignant cells have not been elucidated and may be important to understanding treatment-related toxicity. The purpose of this study was to examine the effect of ARA-C on nondividing vascular endothelial cells. The objectives were to determine the effects of ARA-C on cell viability and to ascertain whether ARA-C caused apoptosis in cultured vascular endothelial cells and hydrocortisone blunted caspase-3-induced apoptosis. Endothelial cells were cultured until confluent and mitotically quiescent then exposed to ARA-C (10-7 to 10-3 M) for 1 to 4 days. Some experiments involved cotreatment with hydrocortisone (10-11 ,10-10 ,10-4 , and 10-3 M). Light microscopy and the colorimetric MTS assay were used to measure viability. Fluorescent annexin-V and DNA fragmentation assays were used to measure apoptosis, and a fluorescence-based enzymatic assay was used to measure caspase-3 activity, which is one pathway involved in the apoptosis cascade. Two-way ANOVA or the appropriate nonparametric test was used to determine statistical significance in studies of viability and apoptosis. Oneway ANOVA was used to determine statistical significance for caspase-3 activity. Viability was decreased with higher concentrations of ARA-C and increased days of treatment. The percentage of apoptotic cells increased with higher concentrations of ARA-C and increased days of treatment. ARA-C-treated samples showed DNA fragmentation, indicative of apoptosis. Caspase-3 activity increased after ARA-C addition; hydrocortisone blunted this increase. ARA-C caused apoptosis in nondividing endothelial cells in culture. Hydrocortisone may protect against ARA-C-induced apoptosis by reducing caspase-3 activity.
Noncholesterol-Lowering Effects of Statins
Authors: Pierre-Paul Daphne , Gahtan Vivian
Published: March 2006

Statins, 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase inhibitors, inhibit the rate-limiting enzyme in cholesterol synthesis and lead to a significant reduction of plasma lipid concentrations. As a clear correlation exists between serum cholesterol and cardiovascular risk, statins have become increasingly important in current preventive medicine. Studies prompted by the extraordinary benefits afforded by these drugs have reported minimal changes in the vasculature of hypercholesterolemic patients when compared with clinical benefits and have led to further investigations to determine the underlying reasons for these clinical benefits. The purpose of this review is to present the wide array of systems that HMGCoA reductase inhibitors are known to influence, which range from adverse events due to coronary artery disease, stroke risk, platelet function, endothelial function, and inflammatory effects to intracellular signaling pathways that control vascular cell migration, proliferation, and differentiation.
Carotid Artery Stenting: Current Status and Future Directions
Authors: Lin Peter H. , Bush Ruth L. , Lumsden Alan B.
Published: March 2006

Carotid endarterectomy has been the mainstay of therapy for carotid occlusive disease in stroke prevention. Recent advances in endovascular technology has made carotid angioplasty and stenting a therapeutic modality in the treatment of carotid occlusive disease. The enthusiasm for this minimally invasive carotid intervention is hampered by the possibility of stentrelated cerebral embolization, which can result in neurologic complications. Although current available data indicate that the results regarding success and complication rates are similar between carotid stenting and endarterectomy, numerous prospective clinical trials are currently underway to evaluate the efficacy of carotid artery stenting using various forms of cerebral protection devices. This article reviews the current status of carotid stenting, including recent clinical studies and ongoing prospective trials. Strategies relating to cerebral embolization protection are also discussed.
“Fast-Track” Abdominal Aortic Aneurysm Repair
Authors: Mukherjee Dipankar
Published: March 2006

The “open” repair of abdominal aortic aneurysm (AAA) continues to evolve with incorporation of less invasive methods for surgical exposure and the use of patient care pathways for shorter hospital stays. In a consecutive series of 30 patients with infrarenal AAA, a “ fasttrack” hospital care pathway was implemented that included the following: AAA exposure via a limited (10–15 cm) retroperitoneal incision, use of self-retaining retractor and special vascular clamps/instruments, and prosthetic graft endoaneurysmorrhaphy. Excellent anatomic exposure for graft implantation was achieved with an average operative time of 175 minutes. Use of oral metoclopromide and patient-controlled epidural analgesia resulted in patient ambulation and oral diet on postoperative day 1. Average length of hospital stay was 3.6 days (range: 3–7 days), and no patient required readmission for AAA repair-related or gastrointestinal problems. One patient died (30-day mortality rate of 3.3%) caused by delayed recognition of a splenic injury, and 1 patient sustained an intraoperative ureter injury that was repaired and stented. Although stent-graft exclusion for AAA repair has become popular, the major advantages of endovascular therapy, such as shorter ICU and hospital stays, earlier dietary feeding, and reduction in postoperative morbidity, can also be achieved by using minimal incision exposure for AAA interposition grafting combined with traditional hand-sewn vascular anastomoses. “Fast-track” AAA repair is applicable to the majority of patients with infrarenal AAAs, and vascular surgeons can easily master the technique of “limited” incision retroperitoneal exposure. This approach avoids the concerns of endovascular stent-graft durability and the mandatory vascular imaging follow-up to identify endoleak development and AAA enlargement.
Upper Arm Polytetrafluoroethylene Grafts for Dialysis Access. Analysis of Two Different Graft Sizes: 6 mm and 6–8 mm
Authors: Garcìa-Pajares Rosario , Polo Josè R. , Flores ¡ngel , Gonzalez-Tabares Enrique , Solìs Juan V.
Published: March 2006

The purpose of this retrospective study was to analyze 2 sizes of expanded polytetrafluoroethylene (PTFE) upper arm grafts for dialysis: 8 millimeters, tapered to 6 mm at the arterial side, and 6 millimeters. All upper arm PTFE grafts (Gore-Tex®) were performed between January 1981 and April 1997. Patient characteristics, complication rate, and patency rates were compared for both kind of grafts. Five hundred and seven PTFE grafts were analyzed (183 6-mm grafts and 324 6- to 8-mm grafts). Early failure was found in 5 grafts (2.7%) in 6-mm grafts, and in 5 grafts (1.5%) in 8-mm grafts (not significant). Steal syndrome was found in 1 patient (0.5%) of the 6-mm group, and in 11 (3.4%) of the 8-mm grafts (p=0.085). The rate of late complications requiring surgical repair was 0.56 episode per graft-year in the 6-mm grafts group, and 0.33 in the 8-mm grafts (p<0.001). Primary patency rates of 6-mm grafts were 72%, 33%, and 19% at 1, 3, and 5 years; and secondary patency rates were 86%, 68%, 56%, and 44% at 1, 3, 5, and 6 years, respectively. In the 8-mm grafts group, primary patency rates were 77%, 52%, and 39% at 1, 3, and 5 years; and secondary patency rates were 92%, 84%, 73%, and 66% at 1, 3, 5, and 6 years, respectively. Comparison of patency rates of 6-mm and 8-mm grafts were statistically significant (p< 0.001) for both primary and secondary curves. However, secondary survival curves were similar for both kind of grafts in a subpopulation of diabetic patients. The authors conclude that the 8-mm graft, tapered to 6 mm at the arterial side, is a dialysis graft with fewer complications and a better patency rate than grafts of 6 mm placed in the same anatomical position, at least in a population of nondiabetic patients. Steal syndrome was observed in some cases of diabetic and older patients with a large-bore graft. Thus, this kind of prosthesis should be avoided in this population. On the other hand, this is not a prospective, randomized study made with any intention for comparison. Therefore, the aforementioned conclusions must be cautiously considered.