What's Missing from Data Modernization? A Focus on Structural Racism

Public health data modernization efforts frequently overlook the far-reaching effects of structural racism across the data life cycle. Modernizing data requires creating data ecosystems grounded in six principles: dismantling structural racism and building community power explicitly; centering justice in all stages of data collection and analysis; ensuring communities can govern their data; driving positive population-level change; engaging nonprofit organizations; and obtaining commitments from governments to make changes in policy and practice. As government agencies spearhead and finance data modernization initiatives, it is imperative that they address structural racism head-on and integrate these principles into all aspects of their work.

Structural Racism and Pedestrian Safety: Measuring the Association Between Historical Redlining and Contemporary Pedestrian Fatalities Across the United States, 2010‒2019

Objectives. To examine the association between historical redlining and contemporary pedestrian fatalities across the United States. Methods. We analyzed 2010-2019 traffic fatality data, obtained from the Fatality Analysis Reporting System, for all US pedestrian fatalities linked by location of crash to 1930s Home Owners' Loan Corporation (HOLC) grades and current sociodemographic factors at the census tract level. We applied generalized estimating equation models to assess the relationship between the count of pedestrian fatalities and redlining. Results. In an adjusted multivariable analysis, tracts graded D ("Hazardous") had a 2.60 (95% confidence interval = 2.26, 2.99) incidence rate ratio (per residential population) of pedestrian fatalities compared with tracts graded A ("Best"). We found a significant dose‒response relationship: as grades worsened from A to D, rates of pedestrian fatalities increased. Conclusions. Historical redlining policy, initiated in the 1930s, has an impact on present-day transportation inequities in the United States. Public Health Implications. To reduce transportation inequities, understanding how structurally racist policies, past and present, have an impact on community-level investments in transportation and health is crucial. (Am J Public Health. 2023;113(4):420-428. https://doi.org/10.2105/AJPH.2022.307192).

Connections Lab: a case study exploring a web-based innovation designed to advance shared risk and protective factor approaches to preventing injuries and violence

BACKGROUND

Injuries and violence share many of the same risk and protective factors, which are rooted in the social determinants of health (SDOH) and the social determinants of equity. Addressing shared risk and protective factors (SRPFs)-common factors that make it more or less likely that a population will experience injuries or violence-is critical prevention efforts. The Safe States Alliance created the Connections Lab-a suite of web-based resources to help injury and violence prevention public health practitioners and their partners understand, describe, implement and evaluate SRPF approaches.

DESIGN

A mixed-methods approach using the Diffusion of Innovation Theory assessed how the Connections Lab influenced users' knowledge, abilities and work related to SRPF approaches. A web-based survey was administered to 234 participants in April-May 2021. Semistructured virtual group discussions were conducted with a subset of 15 survey respondents who volunteered to participate.

RESULTS

The case study revealed three key findings. The Connections Lab: was diffused among practitioners across sectors within and outside of public health; it increased practitioners' perceived proficiency across 10 skill sets related to describing, planning, implementing and evaluating SRPF approaches; and it increased understanding of the importance of upstream and structural drivers of injuries and violence.

CONCLUSION

The Connections Lab was a critical first step to expand the definition of SRPF approaches, connect SRPFs to concepts of equity and the SDOH, and provide strategies for engaging partners in public health and across other sectors in SRPF approaches.

Synthesis and Screening of Novel Peptides on Human Pancreatic Islets for Type 1 Diabetes Therapies. Annu Int Conf IEEE Eng Med Biol Soc 2020;2020:2217-2220. [PMID: 33018448 DOI: 10.1109/embc44109.2020.9175493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Type 1 diabetic patients characteristically exhibit a loss of insulin production, leading to chronic hyperglycemia and related complications. Herein we describe the design, synthesis and screening of novel oligopeptides for their potential to enhance the secretion of insulin from human pancreatic islets. The investigation of these compounds, based off the patented INGAP-PP sequence, aims to identify the peptide features key to maximizing insulin secretion.Clinical Relevance - This report describes the relative efficacy of selected novel compounds for potential Type 1 Diabetes Therapy. Tested on live human pancreatic islets, the compounds are evaluated for their enhancing/inhibitory effect on the secretion of insulin. These studies pave the way for future targeted drug therapies.

Law Accommodating Nonmotorized Road Users and Pedestrian Fatalities in Florida, 1975 to 2013

OBJECTIVES

To examine the effect of Florida's adoption of Statute 335.065-a law requiring the routine accommodation of nonmotorized road users (i.e., a "Complete Streets" policy)-on pedestrian fatalities and to identify factors influencing its implementation.

METHODS

We used a multimethod design (interrupted time-series quasi-experiment and interviews) to calculate Florida's pedestrian fatality rates from 1975 to 2013-39 quarters before and 117 quarters after adoption of the law. Using statistical models, we compared Florida with regional and national comparison groups. Semistructured interviews were conducted with 10 current and former Florida transportation professionals in 2015.

RESULTS

Florida's pedestrian fatality rates decreased significantly-by at least 0.500% more each quarter-after Statute 335.065 was adopted, resulting in more than 3500 lives saved across 29 years. Interviewees described supports and challenges associated with implementing the law.

CONCLUSIONS

Florida Statute 335.065 is associated with a 3-decade decrease in pedestrian fatalities. The study also reveals factors that influenced the implementation and effectiveness of the law. Public Health Implications. Transportation policies-particularly Complete Streets policies-can have significant, quantifiable impacts on population health. Multimethod designs are valuable approaches to policy evaluations.

Giant electron-hole transport asymmetry in ultra-short quantum transistors

Making use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e−h charging energy asymmetry). We parameterize the e−h transport asymmetry by the ratio of the hole and electron charging energies η_e−h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, η_e−h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV.

By utilizing electron-hole asymmetry in ultra-short single-walled carbon nanotube (SWCNT) transistors, McRae et al., develop ‘two-in-one' SWCNT quantum devices that can switch from behaving as quantum-dot transistors for holes to quantum buses for electrons by changing the transistor's gate voltage

A population-based study of the epidemiology of pancreatic cancer: a brief report

OBJECTIVE

Administrative data are used to describe the pancreatic cancer (pcc) population. The analysis examines demographic details, incidence, site, survival, and factors influencing mortality in a cohort of individuals diagnosed with pcc.

METHODS

Incident cases of pcc diagnosed in Ontario between 1 January 2004 and 31 December 2011 were extracted from the Ontario Cancer Registry. They were linked by encrypted health card number to several administrative databases to obtain demographic and mortality information. Descriptive, bivariate, and survival analyses were conducted.

RESULTS

During the period of interest, 9221 new cases of pcc (4548 in men, 4673 in women) were diagnosed, for an age-adjusted standardized annual incidence in the range of 8.6-9.5 per 100,000 population. Mean age at diagnosis was 70.3 ± 12.5 years (standard deviation). Five-year survival was 7.2% (12.8% for those <60 years of age and 3.6% for those >80 years of age). Survival varied by sex, older age, rural residence, lower income, site of involvement in the pancreas, and presence of comorbidity.

CONCLUSIONS

The mortality rate in pcc is exceptionally high. With an increasing incidence and a mortality positively associated with age, additional support will be needed for this highly fatal disease as demographics in Ontario continue to trend toward a higher proportion of older individuals.

Health system costs for stage-specific breast cancer: a population-based approach

OBJECTIVE

The objective of the present analysis was to determine the publicly funded health care costs associated with the care of breast cancer (bca) patients by disease stage.

METHODS

Incident cases of female invasive bca (2005-2009) were extracted from the Ontario Cancer Registry and linked to administrative datasets from the publicly funded system. The type and use of health care services were stratified by disease stage over the first 2 years after diagnosis. Mean costs and costs by type of clinical resource used in the care of bca patients were compared with costs for a matched control group. The attributable cost for the 2-year time horizon was determined in 2008 Canadian dollars.

RESULTS

This cohort study involved 39,655 patients with bca and 190,520 control subjects. The average age in those groups was 61.1 and 60.9 years respectively. Most bca patients were classified as either stage i (34.4%) or stage ii (31.8%). Of the bca cohort, 8% died within the first 2 years after diagnosis. The overall mean cost per bca case from a public payer perspective in the first 2 years after diagnosis was $41,686. Over the 2-year time horizon, the mean cost increased by stage: i, $29,938; ii, $46,893; iii, $65,369; and iv, $66,627. The attributable cost of bca was $31,732. Cost drivers were cancer clinic visits, physician billings, and hospitalizations.

CONCLUSIONS

Costs of care increased by stage of bca. Cost drivers were cancer clinic visits, physician billings, and hospitalizations. These data will assist planning and decision-making for the use of limited health care resources.

Population-based home care services in breast cancer: utilization and costs

OBJECTIVE

To determine utilization and costs of home care services (hcs) for individuals with a diagnosis of breast cancer (bc).

METHODS

Incident cases of invasive bc in women were extracted from the Ontario Cancer Registry (2005-2009) and linked with other Ontario health care administrative databases. Control patients were selected from the population of women never diagnosed with any type of cancer. The types and proportions of hcs used were determined and stratified by disease stage. Attributable home care utilization and costs for bc patients were determined. Factors associated with hcs costs were assessed using regression analysis.

RESULTS

Among the 39,656 bc and 198,280 control patients identified (median age: 61.6 years for both), 75.4% of bc patients used hcs (62.1% stage i; 85.7% stage ii; 94.6% stage iii; 79.1% stage iv) compared with 14.6% of control patients. The number of hcs used per patient-year were significantly higher for the bc patients than for the control patients (14.97 vs. 6.13, p < 0.01), resulting in higher costs per patient-year ($1,210 vs. $325; $885 attributable cost to bc, p < 0.01). The number of hcs utilized and the associated costs increased as the bc stage increased. In contrast, hcs costs decreased as income increased and as previous health care exposure decreased.

INTERPRETATION

Patients with bc used twice as many hcs, resulting in costs that were almost 4 times those observed in a matched control group. Less than an additional $1000 per bc patient per year were spent on hcs utilization in the study population.

The role of attentional focus in plyometric training

AIM

The purpose of this study was to examine how focusing attention during nine weeks of plyometric training influence jumping performance. It was hypothesized that participants utilizing an external focus of attention during practice would produce greater improvements in jumping behavior compared to participants practicing in the internal and control conditions.

METHODS

Thirty-six untrained but physically active male college students were randomly assigned to 1 of 3 plyometric groups with a different focus of attention: external (EXF; N.=12), internal (INF; N.=12), and control (CON; N.=12). All participants subsequently participated in the same an 9-week periodized training program. Standing long jump (SLJ), countermovement jump (CMJ) and drop jump (DJ) were tested pre- and posttraining intervention.

RESULTS

The EXF group exhibited greater improvement (P<0.05) in jumping distance for SLJ and height for CMJ than both the INF and CON groups, while the enhancement in jumping height for DJ was not superior (P<0.05) in the EXF group in comparison with the INF and CON groups. However, the CON group showed a greater increase (P<0.05) in jumping height for DJ than the INF group. The EXF group increased the range of knee flexion (KF), whereas both the INF and CON groups decreased the KF during the CMJ. Additionally, only the CON group reduced KF during the execution of the DJ. The EXF group (P<0.05) increased contact time, whereas both the INF and CON groups decreased (P<0.05) contact time in DJ. The EXF group had significantly (P<0.05) greater vertical ground reaction force in CMJ and DJ when compared with the INF and CON groups.

CONCLUSION

These results suggest that the external focus of attention during plyometric training may provide a greater stimulus to jump performance in slow stretch shortening cycle (SSC) tasks by producing greater force than adopting the internal and no specific focus.

Telemedicine and telepresence for trauma and emergency care management

The use of telemedicine is long-standing, but only in recent years has it been applied to the specialities of trauma, emergency care, and surgery. Despite being relatively new, the concept of teletrauma, telepresence, and telesurgery is evolving and is being integrated into modern care of trauma and surgical patients. This paper will address the current applications of telemedicine and telepresence to trauma and emergency care as the new frontiers of telemedicine application. The University Medical Center and the Arizona Telemedicine Program (ATP) in Tucson, Arizona have two functional teletrauma and emergency telemedicine programs and one ad-hoc program, the mobile telemedicine program. The Southern Arizona Telemedicine and Telepresence (SATT) program is an inter-hospital telemedicine program, while the Tucson ER-link is a link between prehospital and emergency room system, and both are built upon a successful existing award winning ATP and the technical infrastructure of the city of Tucson. These two programs represent examples of integrated and collaborative community approaches to solving the lack of trauma and emergency care issue in the region. These networks will not only be used by trauma, but also by all other medical disciplines, and as such have become an example of innovation and dedication to trauma care. The first case of trauma managed over the telemedicine trauma program or "teletrauma" was that of an 18-month-old girl who was the only survival of a car crash with three fatalities. The success of this case and the pilot project of SATT that ensued led to the development of a regional teletrauma program serving close to 1.5 million people. The telepresence of the trauma surgeon, through teletrauma, has infused confidence among local doctors and communities and is being used to identify knowledge gaps of rural health care providers and the needs for instituting new outreach educational programs.

Representing older and disabled people in virtual user trials: data collection methods

A database was developed to support the creation of a computer-based tool which will support design teams in evaluating the usability of a design during early prototyping and indicate which individuals are effectively excluded or designed out. Methods are described for the collection of multivariate data on 100 real individuals covering a range of physical characteristics and capabilities. These data were tested to ensure a breadth of representation of individuals (particularly older and disabled people) in terms of anthropometry, joint constraints, postural capabilities and task behaviours. The concept of the design tool itself is explored by conducting virtual user trials in the computer-aided design environment. The novel approach of the research encourages empathy with individual users and allows generic abilities, such as bending, reaching and lifting to be assessed.

The efficacy of nicorandil, calcium chloride and nitroglycerin in treatment of ropivacaine-induced cardiotoxicity

BACKGROUND AND OBJECTIVE

The amide-linked local anaesthetics, bupivacaine and ropivacaine, can cause depression of cardiac contractility and dysrhythmias. In a previous study, we observed decreased contractility and ST segment depression following ropivacaine administration in anaesthetized dogs. The efficacy of intravenous (i.v.) and intracoronary nicorandil (30 and 100 microg kg(-1)), i.v. nitroglycerin (glyceryl trinitrate) (5 microg kg(-1)) and calcium chloride (1, 2 and 4 mmol) in reversing the cardiotoxic effects of intracoronary ropivacaine were studied following the administration of intracoronary ropivacaine.

METHODS

Six dogs were studied. The dogs were anaesthetized with i.v. pentobarbital (30 mg kg(-1)). A left-sided thoracotomy was performed and the left circumflex coronary was cannulated. For each dog, the dose of ropivacaine was identified, which produced measurable cardiotoxicity. In each case, ropivacaine was followed by one of the three resuscitation drugs. The effects of each resuscitation drug on ST segments and left ventricular contractility (dP/dt) produced by ropivacaine alone were compared with those produced by ropivacaine followed by each of the three resuscitation drugs using Fisher's exact test.

RESULTS

The doses of ropivacaine required to produce depression of left ventricular dP/dt and ST segments ranged from 1 to 8 mg. Ropivacaine-induced depression of left ventricular contractility (dP/dt) was more rapidly and completely reversed by calcium chloride than by either nitroglycerin or nicorandil (P = 0.008).

CONCLUSIONS

Calcium chloride may be effective in the treatment of inadvertent intravascular administration of amide local anaesthetic agents.

The prevalence of musculoskeletal troubles among car drivers

In order to explore the relationship between car driving and musculoskeletal troubles, a cross-sectional structured-interview survey of low- to high-mileage drivers (including individuals who drove as part of their job) was conducted based on the Nordic Musculoskeletal Questionnaire. The results clearly showed that exposure to car driving was associated with reported sickness absence due to low back trouble and that those who drive as part of their job appear to be more at risk from low back trouble than those whose jobs primarily involve sitting (not driving) and standing activities. The frequency of reported discomfort also increased with higher annual mileage. In addition, drivers of cars with more adjustable driving packages had fewer reported musculoskeletal troubles. This identifies an urgent need for the training of managers of fleet vehicles in the importance of developing measures to reduce this problem, for example, the selection of an individual's car with respect to comfort and postural criteria.

Epidural ropivacaine hydrochloride during labour: protein binding, placental transfer and neonatal outcome

This study was undertaken: (i) to quantify the effects of labour and epidural analgesia on plasma alpha1-acid glycoprotein concentration, (ii) to examine the effects of changes in plasma alpha1-acid glycoprotein concentration on plasma protein binding and placental transfer of ropivacaine, and (iii) to examine the association between umbilical venous ropivacaine concentration and neurobehavioural function in the neonate. Multiparous patients undergoing induction of labour received a continuous epidural infusion of 0.1% ropivacaine following an epidural bolus. A significant association was demonstrated between maternal plasma alpha1-acid glycoprotein concentration and 1/free fraction of ropivacaine 60 min after starting ropivacaine administration (r(2) = 0.77) but not at delivery. No significant correlation was demonstrable between maternal unbound ropivacaine concentration and either neonatal (cord) ropivacaine concentration or UV/MV (a measure of placental transfer). Thirty minutes after delivery, 9/10 neonates had neurological and adaptive capacity scores < 35, whereas only three infants had scores < 35 at 2 h. All scores exceeded 35 16 h after delivery. No association between mean (SD) umbilical venous ropivacaine concentration [0.09 (0.08) mg x l(-1)] and neurological and adaptive capacity scores was demonstrated.

Trauma attending in the resuscitation room: does it affect outcome?

Although there are no Class I data supporting the regionalization of trauma care the consensus is that trauma centers decrease morbidity and mortality. However, the controversy continues over whether trauma surgeons should be in-house or take call from home. The current literature does not answer the question because in all of the recent studies the attendings who took call from home were in the resuscitation room guiding the care. We believe the correct question is: Does the presence of the trauma attending in the resuscitation room make a difference? At a university-affiliated Level II trauma center data from the trauma registry, resuscitation room flowsheet, and dictated admission notes were reviewed on all patients over a 6-month period. Data points were: attending present in the resuscitation room, standard demographics, resuscitation room time, time to operating room (OR), time to CT scan, length of stay, complications, and mortality. A total of 943 patients were studied with 216 (23%) having the attending present in the resuscitation room and 727 (77%) without the attending present. The groups were similar in terms of age, sex, Injury Severity Score, percentage Injury Severity Score greater than 15 (16-17.1%), and mechanism of injury (24-29% penetrating). Of all the data points studied only time to the OR had a statistically significance difference (P < 0.05) with it taking 43.8 minutes (+/-20.1) when the attending was present and 109.4 minutes (+/-107) when the attending was absent. There were also no missed injuries, delays to the OR, or inappropriate workups when the attendings were present. Only the time to the OR reached statistical significance. The time to the OR is indicative of the decision-making process in the resuscitation room, and it is in this area that the attendings' presence is the most useful. Also, we believe that it is important that there were no missed injuries, delays to the OR, or inappropriate workups when the attendings were present in the resuscitation room. This again speaks to the decision-making process. We believe that these data support the need for the attending to be present in the resuscitation room to facilitate accurate and timely decisions regardless of whether they take the call from home or in-house.

Cyanide toxicity in the surgical intensive care unit: a case report

Hypertension is a widespread entity in the surgical intensive care unit. Not only is the clinical spectrum varied, but the armamentarium available to the clinician is also wide-ranging. Sodium nitroprusside, a potent vasodilator with a short half-life, is often used for hypertensive crisis and to deliberately maintain a low blood in certain clinical conditions. Cyanide toxicity is a known complication of sodium nitroprusside use. Herein is reported a case of probable cyanide toxicity in an elderly trauma patient. The pharmacology of sodium nitroprusside and the pitfalls of making the diagnosis of cyanide toxicity are discussed.

Should trauma surgeons render definitive vascular repair in peripheral vascular injuries?

Our hypothesis is that in an established Level I trauma center general trauma surgeons should repair peripheral vascular injuries even in stable patients when there is time for a vascular consult. We reviewed all penetrating peripheral vascular injuries in stable patients operated on by nine experienced general trauma surgeons (1993-1996). Outcome measures were amputation, nerve damage, and vascular complications. There were 43 patients with 44 peripheral vascular injuries identified. Sixty per cent were from stab wounds. There were 27 arterial injuries (carotid four, subclavian one, vertebral two, axillary three, brachial eight, ulnar one, radial two, femoral five, and anterior tibial one). There were three venous injuries (one each subclavian, axillary, and popliteal). There were 14 combined injuries (vertebral two, femoral nine, and popliteal three). There were no mortalities. Morbidity was limited to patients with lower extremity injuries. In the nine patients with combined femoral vessel injury there were three complications (nerve damage, thrombosed arterial repair, and thrombosed venous repair). In the four patients with popliteal venous injuries there were two complications, both venous thrombosis. Our early arterial patency rate was 97.6 per cent. These data support the hypothesis that general surgeons with trauma experience can provide effective treatment of peripheral vascular injuries. The significance of these findings in improving the image of trauma surgery as a career is discussed.

Digital rectal examination for trauma: does every patient need one?

The digital rectal examination is widely accepted as an essential component in the initial assessment of trauma. However, no data have been published that justify its routine use in all seriously injured patients. The objective of this study was to determine what if any impact on subsequent treatment and management decisions the initial digital rectal examination had on injured patients arriving at our emergency department (ED). We conducted a prospective observational study of all injured patients arriving at a Level II trauma center over a period of 6 months. A digital rectal examination was performed on all patients during the secondary survey phase of their initial evaluation shortly after arrival to the ED. The results of the rectal examination were noted for each patient with particular attention placed on the presence or absence of gross blood, Hemoccult result, prostatic examination, rectal vault integrity, and rectal sphincter tone. In addition the patient's hemodynamic parameters while in the ED and the injuries that were sustained were noted, as was their final disposition. Four hundred twenty-three patients were admitted to the ED after sustaining serious injuries. The mean Injury Severity Score was 9.96. The prostatic examination was normal in more than 99 per cent of patients; no high-riding or nonpalpable prostate glands were noted. Twenty-two patients (5.2%) were Hemoccult positive, but in none of these cases did the presence of occult blood in the stool lead to a change in the initial management or diagnostic approach. Three patients (0.7%) with penetrating injuries to the perineal/pelvic area had gross blood on digital rectal examination that prompted operative exploration to rule out a lower gastrointestinal injury. All three had rectal injuries confirmed at surgery. Rectal sphincter tone was normal in 406 (96%) patients, weak in 17 (4%), and absent in none. The only patient in whom the sphincter tone influenced management was an individual complaining of complete paralysis after a blunt mechanism of injury. He had normal rectal sphincter tone and admitted to malingering shortly thereafter. Overall the rectal examination influenced therapeutic decision making in five cases (1.2%). The digital rectal examination is unlikely to affect initial management when applied indiscriminately to all seriously injured patients during the secondary survey. Patients in whom the rectal examination may have a higher probability of influencing management are those with penetrating injuries in proximity to the lower gastrointestinal tract, questionable spinal cord damage, and severe pelvic fractures with potential urethral disruption or open fractures in continuity with the rectal vault. The Hemoccult test does not add useful information and should be discontinued as part of the secondary survey of injured patients.

Relationship between antiphospholipid antibodies and progression of lower extremity arterial occlusive disease after lower extremity bypass operations

PURPOSE

Antiphospholipid antibodies (APLs), which consist of anticardiolipin antibodies (ACLs) or lupus anticoagulant (LA), are associated with venous thrombosis, stroke, and cardiac events. Although they are present in many patients with lower extremity atherosclerotic occlusive disease (LEAOD), the relationship between APL and the progression of LEAOD has not been reported. A comparison of progression of LEAOD as determined with direct imaging studies in patients with and without APL forms the basis for this report.

METHODS

APL+ patients (immunoglobulin M [IgM] or IgA or IgG ACL > 3 SD units above control mean or positive LA) who underwent lower extremity bypass grafting between January 1990 and June 1999 (n = 79) were compared with an APL control group (n = 68). Members of the study and control groups were similar with respect to age, procedure, sex, length of follow-up, and multiple atherosclerosis risk factors. Progression of LEAOD was determined by comparing preoperative arteriograms with postoperative imaging studies (arteriograms or duplex scanning). External iliac, common femoral, superficial femoral and popliteal arteries were graded as < 50% stenosis, > or = 50% stenosis, or occluded. Posterior tibial and anterior tibial arteries were graded as patent or occluded. Progression was defined as any increase in stenosis category.

RESULTS

The mean follow-up period was 31 months for APL+ and 35 months for APL- patients (P = not significant). Progression of LEAOD occurred in 58 (73%) of 79 APL+ patients and in 25 (37%) of 68 APL- patients (P <.001). There was no difference in progression in external iliac or common femoral arteries. Differences in progression were noted in more distal arteries; APL+ patients had significantly more progression in superficial femoral (45% vs 16%, P <.01), popliteal (31% vs 12%, P <.01), posterior tibial (29% vs 13%, P <.05), and anterior tibial arteries (29% vs 14%, P <.05). Multivariate logistic regression analysis showed a significant independent association between the presence of APL and progression of LEAOD (P <.0001).

CONCLUSION

In this study, the presence of APL in patients undergoing lower extremity bypass operations was a significant independent risk factor for progression of LEAOD. We conclude that this patient group should be closely monitored in the postoperative period and appears ideally suited for prospective studies of therapies to modify LEAOD progression.

Functional outcome after open repair of abdominal aortic aneurysm

INTRODUCTION

Detailed information on functional outcome after open abdominal aortic aneurysm (AAA) repair is sparse. Information about functional outcome of open AAA repair is essential to allow comparison of treatment modalities.

METHODS

To determine the functional outcome of patients after open repair of AAA, we reviewed 154 consecutive, nonemergency open repairs of infrarenal AAAs between 1990 and 1997 and each patient's medical records. Clinical variables were recorded for each patient, as were multiple outcomes, including ambulatory status, independent living status, current medical condition, and the patient's perception of recovery and satisfaction. Eighty-seven patients or their families were available for current telephone interview to obtain information about objective functional activities, including walking and driving, and subjective functional information, including assessment of complete recovery and willingness to undergo AAA repair again. Chart data were available for all 154 patients.

RESULTS

There were 42 women and 112 men. A total of 139 operations were elective, and 15 were urgent. The operative mortality rate was 4%, mean hospital stay was 10.7 +/- 1.3 days, and mean intensive care unit stay was 4.57 +/- 1.17 days. Seventeen (11%) patients required transfer to a skilled nursing facility with a mean stay of 3.66 +/- 2.9 months. All patients were ambulatory preoperatively, whereas at last follow-up (median, 25 months; range, 0.13-108.5 months), 100 (64%) of the patients remained ambulatory, 34 (22%) required assistance, and 12 (14%) were nonambulatory. At current assessment by telephone interview, 33% of patients described a decrease in their functional activity including driving, shopping, and traveling compared with their preoperative status, whereas 67% were unchanged. When asked to assess their own degree of recovery, 64% of patients stated that they experienced complete recovery with an average time to recovery of 3.9 months, whereas 33% said they had not fully recovered at a mean follow-up of 34 months. Sixteen (18%) patients said they would not undergo AAA repair again knowing the recovery process, even though they appeared to fully understand the implication of AAA rupture.

CONCLUSION

Patients undergoing open AAA repair generally experienced significant freedom from surgical complications. However, substantial functional impairment was present. It is unclear whether the functional disability resulted from the AAA surgery or from aging and comorbidities unrelated to surgery.

Long-term functional outcome of neurogenic thoracic outlet syndrome in surgically and conservatively treated patients

PURPOSE

Neurogenic thoracic outlet syndrome (NTOS) in the absence of bony and electrodiagnostic abnormalities, often referred to as disputed NTOS, remains enigmatic. Optimal treatment, especially the role of surgery, is controversial. The long-term functional outcome of a cohort of patients undergoing independent medical examination for disputed NTOS with symptoms sufficiently severe to cause inability to work forms the basis for this report.

METHODS

Patients with disputed NTOS and symptoms sufficiently severe to cause at least temporary inability to work seen for independent medical examinations from 1990-1998 formed the study group. None of the patients were treated by our group. Functional outcome was assessed with information from a standardized telephone interview or patient questionnaire. The patients' ability to return to work and an assessment of their current level of symptoms and symptom progression since the time of onset were determined.

RESULTS

Seventy-nine patients were reevaluated at a mean follow-up of 4.2 years (range, 2-7.5 years) after our initial evaluation. Fifteen patients (19%) underwent first rib resection surgery performed by others, whereas 64 (81%) had no surgery. Patients undergoing surgery had missed more work time than those undergoing conservative management (27.6 +/- 6.0 months vs 14.9 +/- 2.6 months, P <.04). Return to work was achieved in nine patients who were operated on (60%) and in 50 patients who were not operated on (78%) (P = not significant [NS]). Among operated patients, current assessment of symptom severity was severe, moderate, mild, and asymptomatic in 7%, 47%, 40% and 7%, respectively. This distribution did not differ significantly from that observed in nonoperated patients (11%, 55%, 30%, 5%; P = NS). When asked about changes in symptomatic status since onset, 7% of the operated group had complete resolution, 27% had marked improvement, 40% had minimal improvement, 13% had no improvement, and 13% were worse. This did not differ significantly from the change in symptoms reported by the nonoperated group (2%, 30%, 22%, 31%, 16%; P = NS).

CONCLUSION

Most patients with disputed NTOS in this nonrandomized series were able to return to work and demonstrated an improvement of symptoms with long-term follow-up. First rib resection did not improve functional outcome in this group.

Optimizing duplex follow-up in patients with an asymptomatic internal carotid artery stenosis of less than 60%

OBJECTIVES

The Asymptomatic Carotid Atherosclerosis Study established benefit of carotid endarterectomy for 60% to 99% asymptomatic internal carotid artery (ICA) stenosis. Optimal follow-up intervals to detect progression from < 60% to 60%-99% ICA stenosis are unknown. In a previous study from our laboratory, we found that ICAs with < 60% stenosis and peak systolic velocities (PSVs) of 175 cm/s or more on initial duplex were at high risk for progression. Prospective evaluation of this hypothesis and determination of optimal duplex follow-up intervals for asymptomatic patients with < 60% ICA stenosis form the basis of this report.

METHODS

All patients who underwent initial carotid duplex examination for any indication since January 1, 1995, with at least one patent, asymptomatic, previously nonoperated ICA with < 60% stenosis; with 6 months' or greater follow-up; and with one or more repeat duplex examinations were entered into the study. On the basis of the initial duplex examination, ICAs were classified into two groups: those with a PSV less than 175 cm/s and those with a PSV of 175 cm/s or more. Follow-up duplex examinations were performed at varying intervals to detect progression from < 60% to 60%-99% ICA stenosis with criteria previously reported (both PSV > or = 260 cm/s and end-diastolic velocity > or = 70 cm/s).

RESULTS

A total of 407 patients (640 asymptomatic ICAs with < 60% stenosis) underwent serial duplex scans (mean follow-up, 22 months). Three ICAs (0.5%) became symptomatic and progressed to 60%-99% ICA stenosis at a mean of 21 months (all transient ischemic attacks), whereas four other ICAs occluded without stroke during follow-up. Progression to 60%-99% stenosis without symptoms was detected in 46 ICAs (7%) (mean, 18 months). Of the 633 patent asymptomatic arteries, 548 ICAs (87%) had initial PSVs less than 175 cm/s, and 85 ICAs (13%) had initial PSVs of 175 cm/s or more. Asymptomatic progression to 60%-99% ICA stenosis occurred in 22 (26%) of 85 ICAs with initial PSVs of 175 cm/s or more, whereas 24 (4%) of 548 ICAs with initial PSVs less than 175 cm/s progressed (P <.0001). The Kaplan-Meier method was used to determine freedom from progression at 6 months, 12 months, and 24 months, which was 95%, 83%, and 70% for ICAs with initial PSVs of 175 cm/s or more versus 100%, 99%, and 95%, respectively, for ICAs with initial PSVs less than 175 cm/s (P <.0001).

CONCLUSIONS

Patients with < 60% ICA stenosis and PSVs of 175 cm/s or more on initial duplex examination are significantly more likely to progress asymptomatically to 60%-99% ICA stenosis, and progression is sufficiently frequent to warrant follow-up duplex studies at 6-month intervals. Patients with < 60% ICA stenosis and initial PSVs less than 175 cm/s may have follow-up duplex examinations safely deferred for 2 years.

Tribal delimitation and phylogenetic relationships of Loteae and Coronilleae (Faboideae: Fabaceae) with special reference to Lotus: evidence from nuclear ribosomal ITS sequences

The temperate herbaceous tribes Loteae and Coronilleae have traditionally been regarded as taxonomically distinct entities. More recent morphological assessments, however, have challenged this view and suggest combining the two tribes under Loteae. Two key features used to distinguish the Coronilleae from Loteae include jointed fruits and branched root nodules. We evaluate the taxonomic utility of these characters using information derived from phylogenetic analyses of the internal transcribed spacers ITS1 + 2, and the intervening 5.8S region of nuclear ribosomal DNA. Results from this study show that neither the Loteae nor Coronilleae form individual monophyletic groups, and that key fruit and root nodule characters used to distinguish the Coronilleae are homoplastic. Given these data, we support the recognition of a single tribe, Loteae. We also find that Lotus, the largest and most morphologically complex genus in either tribe, is not monophyletic. Rather, it consists of two geographically distinct lineages, Old and New World, each of which are more closely related to other Loteae genera: Old World Lotus are more closely related to Old World Anthyllis, while New World Lotus show closer affinities to Old World Coronilla. These data also have important implications for the biogeography of New World Lotus: equally most parsimonious reconstructions suggest a complex scenario of intercontinental dispersals that involve not only Old World Lotus but Coronilla as well.

Patency and characteristics of lower extremity vein grafts requiring multiple revisions

OBJECTIVES

Multiple (> 1) revisions of lower extremity vein grafts may be required to maintain patency. Characteristics of recurrent lower extremity vein graft lesions and the patency achieved after multiple revisions have not been emphasized in reports on infrainguinal vein graft stenosis. This study was performed to determine (1) the patency of multiply revised lower extremity vein grafts and (2) the timing, location, and angiographic and duplex features of the recurrent lesions.

METHODS

Lower extremity vein grafts that were followed in a duplex surveillance protocol and required revisions from January 1990 through December 1998 were identified. All revisions were preceded by angiography. In multiply revised lower extremity vein grafts, the immediate preoperative angiogram and duplex examination findings, as well as the angiogram made before the previous revision and the duplex study done after the previous revision, were reviewed to characterize recurrent lesions at the time of previous and current graft revision. The patencies of grafts undergoing single and multiple revisions were compared.

RESULTS

A total of 233 lower extremity vein graft revisions were performed; of these, 50 (21%) were repeat revisions. Of grafts requiring more than one revision, 98% were normal on duplex examination after the initial revision. Five-year assisted primary patency of multiply revised grafts (91%) was not different from that of grafts with a single revision (89%; P not significant). Of 60 lesions repaired in the 50 repeat revisions, 29 (48%) were at the previously revised site, and 31 (52%) were at new sites. The time between revisions was less if the same site was revised (11 +/- 2 months) than if a different site required revision (20 +/- 4 months; P <.05). Arteriographic evidence of a minor (< 50% diameter) lesion was present at the time of the initial revision in 23% of cases in which revision of a second site was subsequently required.

CONCLUSION

In our experience, 21% of lower extremity vein grafts requiring initial revision ultimately require additional revisions. Multiply revised lower extremity vein grafts have excellent long-term patency. Lesions occur with equal frequency at the site of prior revision and new sites. Lesions prompting revision at new sites occur significantly later and are infrequently detected on prior imaging studies.

Revascularization of the superior mesenteric artery alone for treatment of intestinal ischemia

OBJECTIVE

Complete revascularization is recommended by many authors for treatment of intestinal ischemia. The observation that postprandial intestinal hyperemia is limited to the superior mesenteric artery (SMA) has suggested to us that SMA revascularization alone should be adequate treatment. We preferentially manage intestinal ischemia with a single bypass graft to the SMA and herein update our results using this approach.

METHODS

Patients were identified from a prospectively established vascular surgical registry. Each patient was assessed for acute versus chronic intestinal ischemia, preoperative angiographic findings, operation used, perioperative morbidity and mortality, late symptomatic relief, cause of death, and life table-determined survival and graft patency. Graft patency was determined by follow-up angiography or duplex scanning.

RESULTS

Fifty bypass grafts to the SMA alone were performed in 49 patients (31 women, 18 men; mean age, 62 years) for treatment of intestinal ischemia. In all patients additional splanchnic arteries were available for bypass grafting. Operative indications were acute symptoms in 21 patients, 14 of whom had bowel infarction; chronic symptoms in 26 patients; and prophylaxis in conjunction with infrarenal aortic surgery in 3 patients. Thirty-two grafts originated from the aorta or an iliac artery, and 18 originated from an aortic graft. There were 40 prosthetic and 10 autogenous conduits. Perioperative mortality was 3% in patients with chronic symptoms and 12% overall. All survivors were symptomatically improved. Mean follow-up was 44 months. Nine-year assisted primary graft patency was 79%, and 5-year patient survival was 61%. Two late deaths occurred in patients with recurrent intestinal ischemia resulting from graft occlusions.

CONCLUSIONS

Bypass grafting to the SMA alone appears to be both an effective and durable procedure for treatment of intestinal ischemia. Our results appear equal to those reported for "complete" revascularization for intestinal ischemia. When the SMA is a suitable recipient vessel, multiple bypass grafts to other splanchnic vessels are unnecessary in the treatment of intestinal ischemia.

The effect of elevated homocysteine levels on adrenergic vasoconstriction of human resistance arteries: the role of the endothelium and reactive oxygen species

PURPOSE

This study investigated the effect of elevated homocysteine levels on adrenergic contraction of human resistance arteries and tested the hypothesis that homocysteine-induced generation of reactive oxygen species contributes to vascular reactivity changes.

METHODS

Small (<200 microm) subcutaneous arteries were cannulated and pressurized in an arteriograph chamber that allowed the measurement of lumen diameter. Two arteries from the same patient were obtained; one was perfused and superfused (intraluminal pressure = 50 mm Hg) with physiologic saline solution (control, n = 6), and the other was perfused and superfused with physiologic saline solution plus 200 micromol/L homocysteine (HC, n = 6); the reactivity to adrenergic stimulation was assessed. Another group of arteries was incubated in 200 micromol/L homocysteine plus 1200 U/mL superoxide dismutase and 120 U/mL catalase (HC + SC, n = 6), and the reactivity to norepinephrine was determined. The vasoreactivity of homocysteine was further assessed in intact (n = 6) and denuded (n = 6) arteries that were precontracted with an intermediate concentration of norepinephrine and homocysteine (20-200 micromol/L) added to the bath while the lumen diameter was continuously recorded.

RESULTS

Sensitivity to norepinephrine was diminished in HC arteries, which increased the median effective concentration (EC(50)) from 0.24 +/- 0.06 micromol/L in control arteries to 0.65 +/- 0.10 micromol/L in HC arteries (P <.01). Homocysteine also caused concentration-dependent vasodilation of arteries contracted with an intermediate concentration of norepinephrine that was greater in intact than denuded arteries, with the half-maximum responses occurring at 61 +/- 6 micromol/L (intact) and 90 +/- 11 micromol/L (denuded; P <.05). There was no significant difference in sodium nitroprusside sensitivity between control and homocysteine arteries (EC(50) = 61 +/- 3 nmol/L vs 50 +/- 19 nmol/L; P >.05) or in sensitivity to acetylcholine (EC(50) = 19 +/- 7 nmol/L vs 12 +/- 3 nmol/L; P >.05). Arteries in the presence of superoxide dismutase and catalase had similarly impaired reactivity to norepinephrine as did homocysteine arteries (EC(50), 0.58 +/- 0.15 micromol/L; P >.05 vs HC, P <.01 vs control).

CONCLUSION

An elevated homocysteine level in vitro diminishes adrenergic contraction, with a differential endothelial versus smooth muscle influence that appears unrelated to the generation of reactive oxygen species.

Is a single preoperative duplex scan sufficient for planning bilateral carotid endarterectomy?

PURPOSE

Duplex scanning is often the sole imaging study before carotid endarterectomy (CEA). Patients with bilateral severe internal carotid artery (ICA) stenosis may be considered for bilateral CEA. High-grade ICA stenosis, however, may artifactually elevate velocity measurements used to quantify stenosis in the contralateral ICA. It is unknown whether ipsilateral CEA will influence duplex determination of the presence of a contralateral 60% to 99% ICA stenosis. This study was performed to determine whether a single preoperative duplex scan is sufficient to plan bilateral CEA.

METHODS

Preoperative and early postoperative carotid duplex scans in patients with bilateral ICA stenosis who underwent unilateral CEA were reviewed. Changes in duplex scans that determined stenosis in the ICA contralateral to the CEA were analyzed. Previously validated criteria used to determine 60% to 99% ICA stenosis were a peak systolic velocity (PSV) of 260 cm/sec or more combined with an end diastolic velocity (EDV) of 70 cm/sec or more.

RESULTS

Over an 8-year period, 460 patients underwent CEA; 107 patients (23.3%) had an asymptomatic 50% to 99% contralateral ICA stenosis by standard criteria (PSV, >125 cm/sec) and an early postoperative duplex scan examination. Of these 107 patients, 38 patients (35.5%) had duplex scan criteria for 60% to 99% contralateral ICA stenosis. In these 38 patients, there was a mean postoperative PSV decrease of 47.7 cm/sec (10.1%) and a mean EDV decrease of 36.0 cm/sec (19.3%) in the ICA contralateral to the CEA. Eight of 38 (21.1%) preoperative contralateral 60% to 99% ICA lesions were reclassified as less than 60% on postoperative duplex scanning. Six of 69 (8.7%) preoperative lesions of less than 60% were reclassified as 60% to 99% on postoperative duplex scan. These six preoperative examinations were all close to the criteria for 60% to 99% stenosis (mean PSV, 232.5 cm/sec; mean EDV, 62.5 cm/sec).

CONCLUSION

One-fifth of patients with apparent 60% to 99% contralateral ICA lesions before the operation have less than 60% stenosis when restudied with duplex scan after unilateral CEA. Lesions below but near the cutoff for 60% to 99% may be reclassified as 60% to 99% on the postoperative duplex scan. These findings mandate that when duplex scanning is used as the sole imaging modality before CEA, patients with severe bilateral carotid stenosis must have an additional carotid duplex examination before operation on the second side.

Effects of respiratory and metabolic pH changes and hypoxia on ropivacaine-induced cardiotoxicity in dogs

We have studied the effects of acute changes in acid-base status and hypoxia on the cardiotoxic effects of intracoronary injection of ropivacaine in anaesthetized dogs. The effects of intracoronary ropivacaine were compared when ropivacaine was administered during eucapnia and during each of another nine states in random order: hypocapnia, hypercapnia, hypoxia, metabolic alkalosis, metabolic acidosis, combined metabolic acidosis and hypocapnia, combined metabolic alkalosis and hypercapnia, combined hypoxia and hypercapnia, and combined metabolic acidosis and hypoxia. Hypocapnic alkalosis consistently reduced the cardiotoxic effects of intracoronary ropivacaine (P < 0.01). Our findings indicate that induction of hypocapnic alkalosis may provide a useful adjunct to standard resuscitative measure after inadvertent administration of amide local anaesthetic agents.

Hypothenar hammer syndrome: proposed etiology

PURPOSE

Finger ischemia caused by embolic occlusion of digital arteries originating from the palmar ulnar artery in a person repetitively striking objects with the heel of the hand has been termed hypothenar hammer syndrome (HHS). Previous reports have attributed the arterial pathology to traumatic injury to normal vessels. A large experience leads us to hypothesize that HHS results from trauma to intrinsically abnormal arteries.

METHODS

We reviewed the arteriography, histology, and clinical outcome of all patients treated for HHS in a university clinical research center study of hand ischemia, which prospectively enrolled more than 1300 subjects from 1971 to 1998.

RESULTS

Twenty-one men had HHS. All had occupational (mechanic, carpenter, etc) or avocational (woodworker) exposure to repetitive palmar trauma. All patients underwent upper-extremity and hand arteriography, unilateral in eight patients (38%) and bilateral in 13 patients (62%). By means of arteriogram, multiple digital artery occlusions were shown in the symptomatic hand, with either segmental ulnar artery occlusion in the palm or characteristic "corkscrew" elongation, with alternating stenoses and ectasia. Similar changes in the contralateral asymptomatic (and less traumatized) hand were shown by means of 12 of 13 bilateral arteriograms (92%). Twenty-one operations, consisting of segmental ulnar artery excision in the palm and vein grafting, were performed on 19 patients. Histology was compatible with fibromuscular dysplasia with superimposed trauma. Patency of arterial repairs at 2 years was 84%. One patient (5%) required amputative debridement of necrotic finger tips. No other tissue loss occurred. There have been no recurrences of ischemia in patients with patent bypass grafts.

CONCLUSION

To our knowledge, this is the largest reported group of HHS patients. The characteristic angiographic appearance, histologic findings, and striking incidence of bilateral abnormalities in patients with unilateral symptoms lead us to conclude that HHS occurs when persons with preexisting palmar ulnar artery fibrodysplasia experience repetitive palmar trauma. This revised theory for the etiology of HHS explains why HHS does not develop in most patients with repetitive palmar trauma.

Does endovascular grafting represent a giant step forward?

Endovascular repair of abdominal aortic aneurysms was first reported in 1991 by Parodi et al. Since then, there has been widespread development of many stent-grafts for abdominal aortic aneurysm (AAA) repair. Available data support the proposition that stent-grafts are generally safe, although their long-term efficacy remains completely unknown. Importantly, endovascular AAA repair has neither fewer complications nor lower mortality rates than open repair; in fact, the opposite appears true. Along with most new techniques come new complications, and endovascular repair of AAA has brought forth the concept of both "endoleak" and device failure. Although it is uncommon, delayed AAA rupture after seemingly successful endovascular repair of AAA has been reported. In our opinion, these faults unique to endovascular repair mandate a cautious approach to the clinical application of stent-grafts. Until ongoing phase 2 and future phase 3 studies are completed with a minimum of 2 to 3 years' follow-up, we shall not know whether endovascular repair of AAA represents a giant step forward or merely an industry-driven overuse of proprietary technology.

Extrathoracic arterial grafts performed for carotid artery occlusive disease not amenable to endarterectomy

HYPOTHESIS

Extrathoracic cervical grafts are safe and provide long-lasting stroke prevention in patients with disease not amenable to standard carotid bifurcation endarterectomy.

DESIGN

Review of a prospectively maintained vascular surgical registry.

SETTING

Combined university and Department of Veterans Affairs vascular surgical service.

PARTICIPANTS

Patients requiring surgery for carotid atherosclerotic occlusive disease not amenable to endarterectomy from January 1988 to March 1998.

INTERVENTIONS

Carotid interposition grafting, subclavian-carotid bypass, or carotid-carotid bypass.

MAIN OUTCOME MEASURES

Perioperative stroke and death, and life-table determination of freedom from stroke, stroke-free survival, and graft patency.

RESULTS

Sixty patients (mean age, 65.8 years; range, 36-83) underwent cervically based carotid grafting. All had greater than 70% stenosis or occlusion of the innominate, common carotid, or internal carotid arteries, and 30 (50%) had undergone at least 1 previous ipsilateral carotid endarterectomy. Indication for operation was stroke or transient ischemic attack in 46 (77%) and asymptomatic high-grade stenosis in 14 (23%). Operative procedures included 31 (52%) carotid interposition grafts, 18 (30%) subclavian-carotid grafts, and 11 (18%) carotid-carotid grafts. Mean follow-up was 29 months (range, 1-117 months). Perioperative stroke rate was 5% (3/60) all in symptomatic patients, and there were no perioperative deaths. By life-table analysis, freedom from stroke was 92% at 1 and 5 years. Stroke-free survival was 90% at 1 year and 61% at 5 years. Primary graft patency was 94% at 1 year and 84% at 5 years, with assisted primary patency of 90% at 5 years.

CONCLUSION

Cervical carotid artery grafts for complicated or recurrent carotid atherosclerosis not amenable to endarterectomy are durable and provide excellent freedom from stroke with low perioperative morbidity and mortality.

The effects of ropivacaine hydrochloride on coagulation and fibrinolysis. An assessment using thromboelastography

Amide local anaesthetics impair coagulation by inhibition of platelet function and enhanced fibrinolysis. The potential therefore exists that the presence of amide local anaesthetics in the epidural space could contribute to the therapeutic failure of an epidural autologous blood patch. Ropivacaine is an aminoamide local anaesthetic increasingly used for epidural analgesia and anaesthesia, particularly in obstetric practice. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur clinically in the epidural space, alter coagulation or fibrinolysis. Thromboelastography was used to assess clotting and fibrinolysis of blood to which ropivacaine had been added. Although modest alterations in maximum amplitude, coagulation time and alpha angle were observed, the effect of ropivacaine on clotting and fibrinolysis was not clinically significant. We conclude that it is unlikely that the presence of ropivacaine in the epidural space would reduce the efficacy of an early or prophylactic epidural blood patch.

Raynaud's syndrome in workers who use vibrating pneumatic air knives

PURPOSE

The use of vibrating tools has been shown to cause Raynaud's syndrome (RS) in a variety of workers, including those who use chain saws, chippers, and grinders. The diagnosis of RS in workers who use vibrating tools is difficult to document objectively. We studied a patient cohort with RS caused by the use of a vibrating pneumatic air knife (PAK) for removal of automobile windshields and determined our ability to document RS in these workers by means of digital hypothermic challenge testing (DHCT), a vascular laboratory study that evaluates digital blood pressure response to cooling.

METHODS

Sixteen male autoglass workers (mean age, 36 years) with RS were examined by means of history, physical examination, arm blood pressures, digital photoplethysmography, screening serologic studies for underlying connective tissue disorder, and DHCT.

RESULTS

No patient had RS before they used a PAK. The mean onset of RS (color changes, 100%; pain, 93%; parathesias, 75%) with cold exposure was 3 years (range, 1.5 to 5 years) after initial PAK use (mean estimated PAK use, 2450 hours). Fifty-six percent of workers smoked cigarettes. The findings of the physical examination, arm blood pressures, digital photoplethysmography, and serologic testing were normal in all patients. At 10 degrees C cooling with digital cuff and patient cooling blanket, a significant decrease in digital blood pressure was shown by means of DHCT in 100% of test fingers versus normothermic control fingers (mean decrease, 75%; range, 25% to 100%; normal response, less than 17%; P <.001). The mean follow-up period was 18 months (range, 1 to 47 months). No patient continued to use the PAK, but symptoms of RS were unchanged in 69% and worse in 31%.

CONCLUSION

PAK use is a possible cause of vibration-induced RS. The presence of RS in workers who use the PAK was objectively confirmed by means of DHCT. Cessation of PAK use in the short term did not result in symptomatic improvement.

Improved results with conventional management of infrarenal aortic infection

PURPOSE

Interest in alternative methods, such as autogenous vein grafts and aortic allografts, for the management of infrarenal aortic infection (IRAI) has been stimulated by the historically disappointing results with conventional surgical management. Recently, there have been dramatic improvements in the results of axillofemoral bypass grafting (AXFB) followed by excision of the IRAI that have gone relatively unrecognized. The purpose of this report is the presentation of modern-day results in the treatment of IRAI with conventional surgical methods.

METHODS

From January 1, 1983, through June 30, 1998, patients with IRAI underwent treatment with AXFB and complete excision of the IRAI. The patients were followed for survival, limb salvage, and AXFB graft patency. The results were tabulated with life-table methods.

RESULTS

During the 15-year study period, 60 patients (51 men, nine women; mean age, 68 years) underwent treatment for IRAI (50 graft infections, including 16 graft-enteric fistulae, and 10 primary aortic infections). The mean follow-up period was 41 months. The perioperative mortality rate was 13% (12% for graft infection, and 20% for primary infection). The overall 2-year and 5-year survival rates were 67% and 47%, respectively. The limb salvage rates at 2 and 5 years were 93% and 82%, respectively. The 5-year primary AXFB graft patency rate was 73%.

CONCLUSION

These results show an improvement with the conventional management of IRAI equal or superior to those results reported with alternative methods, including femoral vein grafts or aortic allografts. These results should be regarded as the modern standard with which alternative therapies can be compared.