Scholars@Duke
Steven Nicholas Vaslef

Steven Nicholas Vaslef

Associate Professor Emeritus of Surgery
Trauma, Acute, and Critical Care Surgery
vasle001@mc.duke.edu
Box 2837 Med Ctr, DUMC, Durham, NC 27710
Room 1557, Duke South - Blue Zone, Durham, NC 27710

Scholarly Works - Journal articles

Postoperative changes in cognition and cerebrospinal fluid neurodegenerative disease biomarkers.

Journal article Ann Clin Transl Neurol · February 2022 OBJECTIVE: Numerous investigators have theorized that postoperative changes in Alzheimer's disease neuropathology may underlie postoperative neurocognitive disorders. Thus, we determined the relationship between postoperative changes in cognition and cereb ... Full text Open Access Link to item Cite

Perioperative neurocognitive and functional neuroimaging trajectories in older APOE4 carriers compared with non-carriers: secondary analysis of a prospective cohort study.

Journal article Br J Anaesth · December 2021 BACKGROUND: Cognitive dysfunction after surgery is a major issue in older adults. Here, we determined the effect of APOE4 on perioperative neurocognitive function in older patients. METHODS: We enrolled 140 English-speaking patients ≥60 yr old scheduled fo ... Full text Open Access Link to item Cite

Acute Respiratory Distress Syndrome (ARDS) after trauma: Improving incidence, but increasing mortality.

Journal article J Crit Care · August 2021 PURPOSE: Acute Respiratory Distress Syndrome (ARDS) is an infrequent, yet morbid inflammatory complication in injury victims. With the current project we sought to estimate trends in incidence, determine outcomes, and identify risk factors for ARDS and rel ... Full text Link to item Cite

Immunomodulatory lipid mediator profiling of cerebrospinal fluid following surgery in older adults.

Journal article Sci Rep · February 4, 2021 Arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) derived lipids play key roles in initiating and resolving inflammation. Neuro-inflammation is thought to play a causal role in perioperative neurocognitive disorders, yet th ... Full text Open Access Link to item Cite

Cerebrospinal Fluid Proteome Changes in Older Non-Cardiac Surgical Patients with Postoperative Cognitive Dysfunction.

Journal article J Alzheimers Dis · 2021 BACKGROUND: Postoperative cognitive dysfunction (POCD), a syndrome of cognitive deficits occurring 1-12 months after surgery primarily in older patients, is associated with poor postoperative outcomes. POCD is hypothesized to result from neuroinflammation; ... Full text Open Access Link to item Cite

A protocol to reduce self-reported pain scores and adverse events following lumbar punctures in older adults.

Journal article J Neurol · July 2020 OBJECTIVE: Lumbar punctures (LPs) are important for obtaining CSF in neurology studies but are associated with adverse events and feared by many patients. We determined adverse event rates and pain scores in patients prospectively enrolled in two cohort st ... Full text Link to item Cite

Flow Cytometry Characterization of Cerebrospinal Fluid Monocytes in Patients With Postoperative Cognitive Dysfunction: A Pilot Study.

Journal article Anesth Analg · November 2019 Animal models suggest postoperative cognitive dysfunction may be caused by brain monocyte influx. To study this in humans, we developed a flow cytometry panel to profile cerebrospinal fluid (CSF) samples collected before and after major noncardiac surgery ... Full text Open Access Link to item Cite

Intraoperative Frontal Alpha-Band Power Correlates with Preoperative Neurocognitive Function in Older Adults.

Journal article Front Syst Neurosci · 2017 Each year over 16 million older Americans undergo general anesthesia for surgery, and up to 40% develop postoperative delirium and/or cognitive dysfunction (POCD). Delirium and POCD are each associated with decreased quality of life, early retirement, incr ... Full text Open Access Link to item Cite

Optimal timing of tracheostomy after trauma without associated head injury.

Journal article J Surg Res · October 2015 BACKGROUND: Controversy exists over optimal timing of tracheostomy in patients with respiratory failure after blunt trauma. The study aimed to determine whether the timing of tracheostomy affects mortality in this population. METHODS: The 2008-2011 Nationa ... Full text Link to item Cite

A Randomized Dose-Escalation Study of the Safety and Anti-Inflammatory Activity of the p38 Mitogen-Activated Protein Kinase Inhibitor Dilmapimod in Severe Trauma Subjects at Risk for Acute Respiratory Distress Syndrome.

Journal article Crit Care Med · September 2015 OBJECTIVES: There are no current pharmacological therapies for the prevention or treatment of acute respiratory distress syndrome. Early dysregulated inflammation likely plays a role in acute respiratory distress syndrome development and possibly acute res ... Full text Link to item Cite

Impact of specific postoperative complications on the outcomes of emergency general surgery patients.

Journal article J Trauma Acute Care Surg · May 2015 BACKGROUND: The relative contribution of specific postoperative complications on mortality after emergency operations has not been previously described. Identifying specific contributors to postoperative mortality following acute care surgery will allow fo ... Full text Link to item Cite

No need to wait: an analysis of the timing of cholecystectomy during admission for acute cholecystitis using the American College of Surgeons National Surgical Quality Improvement Program database.

Journal article J Trauma Acute Care Surg · January 2013 BACKGROUND: The objective of our analysis was to determine the optimal timing of cholecystectomy during admission for acute cholecystitis. METHODS: All patients from the American College of Surgeons National Surgical Quality Improvement Program Participant ... Full text Link to item Cite

A 9-Year retrospective review of antibiotic cycling in a surgical intensive care unit.

Journal article J Surg Res · August 2012 BACKGROUND: Six years after initiating a monthly antibiotic cycling protocol in the surgical intensive care unit (SICU), we retrospectively reviewed antibiogram-derived sensitivities of predominant gram-negative pathogens before and after antibiotic cyclin ... Full text Link to item Cite

Locoregional versus general anesthesia for open inguinal herniorrhaphy: a National Surgical Quality Improvement Program analysis.

Journal article Am Surg · July 2012 Our objective was to study outcomes associated with open inguinal herniorrhaphy performed under locoregional (LR) versus general anesthesia (GA). National Surgical Quality Improvement Program (NSQIP) data from 2005 to 2009 was queried to capture patients u ... Link to item Cite

The rapid impact on mortality rates of a dedicated care team including trauma and emergency physicians at an academic medical center.

Journal article J Emerg Med · May 2011 BACKGROUND: Trauma center designation can result in improved patient outcomes after injuries. Whereas the presence of trauma teams has been associated with improved trauma patient outcomes, the specific components, including the role of emergency medicine ... Full text Link to item Cite

The volume-outcomes relationship for United States Level I trauma centers.

Journal article J Surg Res · May 1, 2011 BACKGROUND: Previous studies of the center volume-outcomes relationship for severe trauma care have yielded conflicting findings regarding the presence or nature of such a relationship. Few studies have confined their analysis to Level I centers. METHODS: ... Full text Link to item Cite

Appendicitis, body mass index, and CT: is CT more valuable for obese patients than thin patients?

Journal article Am Surg · April 2011 The purpose of our study is to determine whether body mass index (BMI = weight in kg/height in meters(2)) was related to the rate of negative appendectomy in patients who underwent preoperative CT. A surgical database search performed using the procedure c ... Link to item Cite

Outcomes and health care resource utilization in super-elderly trauma patients.

Journal article J Surg Res · September 2010 BACKGROUND: Few studies have compared the post-injury outcomes of super-elderly patients to elderly patients. METHODS: We performed a retrospective analysis of 1320 multi-trauma geriatric patients treated at a level I trauma center from 2003 through 2007. ... Full text Link to item Cite

Carcinoid tumors of the appendix: are these tumors identifiable prospectively on preoperative CT?

Journal article Am Surg · March 2010 The purpose of this study was to determine if carcinoid tumors of the appendix were identified prospectively on preoperative CT at our institution during the last decade. A surgical database search performed using the Current Procedural Terminology codes f ... Link to item Cite

Making the diagnosis of acute appendicitis: do more preoperative CT scans mean fewer negative appendectomies? A 10-year study.

Journal article Radiology · February 2010 PURPOSE: To determine the frequency of preoperative computed tomography (CT) in the evaluation of patients suspected of having appendicitis at one institution during the past 10 years and to determine whether changes in CT utilization were associated with ... Full text Link to item Cite

Utilisation of high-frequency oscillatory ventilation in blunt thoracic trauma

Journal article Trauma · January 1, 2010 Blunt thoracic trauma patients are at high risk of mortality when conventional mechanical ventilation fails to sustain respiratory function.We provide an overview of high-frequency oscillatory ventilation (HFOV) as a potential rescue therapy for such patie ... Full text Cite

Does intent matter? The medical and societal burden of self-inflicted injury.

Journal article J Trauma · October 2009 BACKGROUND: The objective of our study was to assess the impact of injury intentionality on the outcomes and healthcare resource utilization of severely injured patients in the United States. METHODS: The National Trauma Data Bank for the years 2001 throug ... Full text Link to item Cite

Multiseptate gallbladder.

Journal article J Gastrointest Surg · September 2009 INTRODUCTION: Multiseptate gallbladder is a rare congenital condition that may be asymptomatic or may lead to symptoms consistent with biliary colic, even in the absence of cholelithiasis. DISCUSSION: We present the case of a 19-year-old female who underwe ... Full text Link to item Cite

A brief report: the use of high-frequency oscillatory ventilation for severe pulmonary contusion.

Journal article J Trauma · August 2008 BACKGROUND: Severe pulmonary contusions are a common cause of acute respiratory distress syndrome (ARDS) and are associated with significant morbidity. High frequency oscillatory ventilation (HFOV) is a ventilatory mode that employs a lung protective strat ... Full text Link to item Cite

Practice management guidelines for the screening of thoracolumbar spine fracture.

Journal article J Trauma · September 2007 BACKGROUND: Fractures to the thoracolumbar spine (TLS) commonly occur because of major trauma mechanisms. In one series, 4.4% of all patients arriving at a Level I trauma center were diagnosed as having TLS fracture. Approximately 19% to 50% of these fract ... Full text Link to item Cite

Implementation of antibiotic rotation protocol improves antibiotic susceptibility profile in a surgical intensive care unit.

Journal article J Trauma · August 2007 BACKGROUND: Antibiotic rotation has been proposed as a way to potentially reduce the development of antimicrobial resistant bacteria in intensive care units. We assessed the effect of an antibiotic rotation protocol on the antibiotic susceptibility profile ... Full text Link to item Cite

Ethical and regulatory challenges associated with the exception from informed consent requirements for emergency research: from experimental design to institutional review board approval.

Journal article Arch Surg · October 2006 Clinical research studies conducted in emergency settings under the waiver of consent provision outlined in federal regulations are uncommon, yet the importance of such research that may result in potentially lifesaving interventions is indisputable. Surge ... Full text Link to item Cite

Oxygen transport dynamics after resuscitation with a conjugated hemoglobin solution.

Journal article Arch Surg · January 2004 HYPOTHESIS: Pyridoxalated hemoglobin polyoxyethylene conjugate (PHP), a hemoglobin-based oxygen carrier, is effective in restoring hemodynamic balance and oxygen delivery after moderate hemorrhage but may be less effective in off-loading oxygen at the tiss ... Full text Link to item Cite

Endoscopic components separation for abdominal compartment syndrome.

Journal article Am J Surg · August 2003 BACKGROUND: Sustained intraabdominal pressures of 14 to 20 mm Hg have significant pathophysiological consequences, but there is currently no satisfactory low-morbidity procedure appropriate for intervention early in the disease process of abdominal compart ... Full text Link to item Cite

Massive transfusion exceeding 50 units of blood products in trauma patients.

Journal article J Trauma · August 2002 Featured Work BACKGROUND: Massive transfusion of blood products in trauma patients can acutely deplete the blood bank. It was hypothesized that, despite a large allocation of resources to trauma patients receiving more than 50 units of blood products in the first 24 hou ... Full text Link to item Cite

Oxygen transport dynamics of acellular hemoglobin solutions in an isovolemic hemodilution model in swine.

Journal article J Trauma · December 2001 Featured Work BACKGROUND: One of the perceived advantages of a hemoglobin-based blood substitute is the provision of oxygen-carrying capacity. Although the hemodynamic response to the infusion of acellular hemoglobin solutions has been extensively studied, less is known ... Full text Link to item Cite

The spectrum of abdominal venous CT findings in blunt trauma.

Journal article AJR Am J Roentgenol · April 2001 Featured Work Full text Link to item Cite

Traumatic vertebrojugular arteriovenous fistula: case report.

Journal article J Trauma · December 2000 Featured Work Full text Link to item Cite

Comparison of the response of saline tonometry and an automated gas tonometry device to a change in CO2.

Journal article Crit Care Med · November 2000 Featured Work OBJECTIVE: To examine the speed of response of saline tonometry and an automated gas tonometry system by using standard tonometry catheters. DESIGN: In vitro validation study. SETTING: Experimental research laboratory. INTERVENTIONS: Tonometry catheters we ... Full text Link to item Cite

Outcome analysis in patients with primary necrotizing fasciitis of the male genitalia.

Journal article Urology · July 2000 Featured Work OBJECTIVES: To characterize patients with primary necrotizing fasciitis of the male genitalia (Fournier's gangrene) and to identify risk factors and prognostic variables of survival. METHODS: Fifty consecutive patients with primary necrotizing fasciitis of ... Full text Link to item Cite

Comparison of various hemoglobin polyoxyethylene conjugate solutions as resuscitative fluids after hemorrhagic shock.

Journal article J Trauma · May 2000 Featured Work BACKGROUND: Previous research suggested that splanchnic hypoperfusion occurs after resuscitation with certain acellular hemoglobin solutions. We examined the influence of maltose content and oxygen affinity on resuscitation with various hemoglobin polyoxye ... Full text Link to item Cite

Gallstone pancreatitis in pregnancy.

Journal article Saudi J Gastroenterol · January 1999 Link to item Cite

Blunt vascular injuries of the head and neck: is heparinization necessary?

Journal article J Trauma · December 1998 BACKGROUND: Blunt vascular injuries to the head and neck (BHVI) represent some of the most devastating and morbid injuries seen by a trauma surgeon. This series reviewed the experience of a single institution to determine if diagnostic and therapeutic guid ... Full text Link to item Cite

Effect of alpha(alpha)-cross-linked hemoglobin and pyridoxalated hemoglobin polyoxyethylene conjugate solutions on gastrointestinal regional perfusion in hemorrhagic shock.

Journal article J Trauma · September 1998 BACKGROUND: Hemoglobin-based blood substitutes may cause vasoconstriction, which could limit organ perfusion during trauma resuscitation. We investigated the effect of two hemoglobin solutions on regional blood flow and mucosal perfusion in the gastrointes ... Full text Link to item Cite

Multiple impalement with survival.

Journal article Am J Emerg Med · January 1997 An unusual case of multiple impalement by chain-link fence posts is presented in which facial, thoracic, and abdominal injuries were sustained following a rollover motor vehicle crash. Torso impalement injuries are briefly reviewed and guidelines for the m ... Full text Link to item Cite

Postoperative care of the trauma patient

Journal article Anesthesiology Clinics of North America · January 1, 1996 The postoperative care of the trauma patient requires an understanding of the use of analgesics, sedatives, and neuromuscular blocking agents, as well as principles of nutritional and metabolic support. Complications in the postoperative period, despite at ... Full text Cite

Computer-assisted design of an implantable, intrathoracic artificial lung.

Journal article Artif Organs · November 1994 A semiempirical mathematical model of convective oxygen transport is used to design a new, low pressure loss, implantable artificial lung that could be used as a bridge to lung transplantation in patients with advanced respiratory failure. The mass transfe ... Full text Link to item Cite

Enhanced oxygen delivery induced by perfluorocarbon emulsions in capillary tube oxygenators.

Journal article ASAIO J · 1994 Previous studies showed that a new generation of perfluorocarbon (PFC) emulsions increased tissue PO2 in the cat retina to a degree that could not be explained by the small increase in arterial O2 content seen after the infusion of low doses of 1 g PFC/kg ... Full text Link to item Cite

Use of a mathematical model to predict oxygen transfer rates in hollow fiber membrane oxygenators.

Journal article ASAIO J · 1994 A semi-empirical theoretical model of oxygen transfer is used to predict the rates of oxygen transfer to blood in hollow fiber membrane oxygenators over a wide range of inlet conditions. The predicted oxygen transfer rates are based on performance of the d ... Link to item Cite

Design and evaluation of a new, low pressure loss, implantable artificial lung.

Journal article ASAIO J · 1994 The authors designed and tested an artificial lung intended for intrathoracic implantation as a bridge to lung transplantation in chronic pulmonary insufficiency or as an alternative in the treatment of advanced acute respiratory failure. The prototype dev ... Full text Link to item Cite

Development of an intravascular lung assist device.

Journal article ASAIO Trans · 1989 Intravascular lung assist devices (ILADs) must provide sufficient gas transport without excessive pressure drop. In vitro studies of fiber-bundle devices determined the effect of geometric configuration on gas transfer efficiency, the amount of surface are ... Full text Link to item Cite