Papers by Christopher Barton
Critical Care Medicine, Mar 1, 1992
To determine if the administration of epinephrine changes the partial pressure of end-tidal CO2 d... more To determine if the administration of epinephrine changes the partial pressure of end-tidal CO2 during cardiac arrest, as previously reported. Such a change could diminish the demonstrated ability of end-tidal CO2 measurements to predict resuscitation from cardiac arrest. The partial pressures of end-tidal CO2 of adult cardiac arrest patients who received i.v. epinephrine in doses from 1 to 15 mg were monitored throughout arrest. Emergency department of a university hospital. Adults (n = 64) in cardiac arrest with a mean age of 70 +/- 12 yrs, of whom 35 were males and 15 had a mean time of return of spontaneous circulation of 6.5 +/- 11 hrs. End-tidal CO2 (in torr) was analyzed on arrival, before the first dose of epinephrine, and 4 mins after epinephrine was administered in varying doses chosen by the supervising physician. The end-tidal CO2 decreased an average of 0.3 torr (0.04 kPa) after epinephrine was administered. Patients with a return of pulse had a decrease of -2 torr (-0.3 kPa) vs. an increase of 0.3 torr (0.04 kPa) for those patients with no return of pulse (p = .07). In 33% of patients, there was no change; in 28%, the partial pressure of end-tidal CO2 increased, and in 39%, it decreased. There was no correlation between the change in end-tidal CO2 after epinephrine and whether or not patients regained a pulse (r2 = .08, p = .07), although a decrease in end-tidal CO2 was most often associated with return of pulse. At a threshold of 10 torr (1.3 kPa), the first end-tidal CO2 had a positive predictive value for return of pulse of 50% and a negative predictive value of 82%. Just before epinephrine administration, the positive predictive value was 71% and the negative predictive value was 83%; 4 mins after epinephrine administration, the positive predictive value was 64% and the negative predictive value was 86%. A decrease in end-tidal CO2 after epinephrine had a positive predictive value of 53% and a negative predictive value of 92%. End-tidal CO2 readings predicted resuscitation most accurately when taken after initial stabilization and before administration of epinephrine. Although epinephrine administration may decrease end-tidal CO2 tensions in cardiac arrest, it does so unpredictably in individual patients, and it does not eliminate the predictive value of this measurement.
ABSTRACT Background/Question/Methods The majority of the Appalachian coal field lies beneath mixe... more ABSTRACT Background/Question/Methods The majority of the Appalachian coal field lies beneath mixed-species, hardwood forests that provide landowners with a valuable, renewable resource. However, in the past, extraction of coal by means of surface mining, limited the options of landowners to return their land to forests due to site reclamation practices such as grading and compaction which discourages forest production. Recently, research conducted in the Appalachian region by the Appalachian Regional Reforestation Initiative (ARRI) has focused on reclamation methods, known as the Forestry Reclamation Approach (FRA), that promote rapid, healthy tree growth on previously surface mined areas. ARRI and The American Chestnut Foundation (TACF), through employment of the FRA, have conducted research projects evaluating American chestnut on previously surface mined areas. Results from these experiments indicate that American chestnut grows very well on these sites. As a result of this initial research, TACF is interested in determining the suitability of its potentially blight-resistant American backcross chestnut, developed in the breeding program at Meadowview, Virginia. As TACF prepares for restoration of the American chestnut, open land suitable for chestnut growth will be needed. Previously surface mined lands could provide ample planting area throughout Appalachia. American, Chinese, and three levels of American-backcross chestnut were used in the study. The objective of the study was to determine if differences in performance and growth exist between the five genotypes of chestnut when grown on formerly surface mined lands. Sites were selected by TACF in cooperation with research scientists at the University of Kentucky, the University of Tennessee, Ohio University, West Virginia University, Pennsylvania State University, and the University of Maryland. Sites were chosen in Kentucky, Tennessee, West Virginia, Maryland, and Ohio, and at three locations in Pennsylvania that reflected reclamation practices as recommended by ARRI and the FRA. Results/Conclusions Results indicate that there are no significant differences among the growth rates of American, Chinese, and the three levels of American backcross chestnuts when grown on previously surface mined sites when grown using the FRA. Based on these results, TACF’s potentially blight-resistant backcross chestnut should provide a suitable level of growth and performance in a mixed-species hardwood stand on these surface mined sites. Chestnut as part of a mixed-species hardwood forest should provide additional value and management options to landowners as they explore different post-mined land uses.
A systematic overview is presented of body immune response from which a primitive mathematical mo... more A systematic overview is presented of body immune response from which a primitive mathematical model is derived as a base for more extensive research. The model provides a basic description of one basic ~lass of cells (B-cells) with extensions for antibody switch-over and secondary response.
Sediment mobilized by forest harvest machine traffic is a major contributor to the degradation of... more Sediment mobilized by forest harvest machine traffic is a major contributor to the degradation of headwater stream systems. This study monitored forest harvest machine traffic in order to analyze how this traffic affects sediment delivery to stream channels. Harvest machines were outfitted with global positioning system (GPS) dataloggers, recording machine movements and working status. Sediment delivery to streams was monitored by scouting for overland sediment delivery paths after the completion of harvest operations. Each sediment path was categorized as to source, width of path where it enters the stream, slope degree and distance to sediment source, ground disturbance level at source, trail morphology at sediment source, and whether a water control structure contributed to sediment delivery. The harvest was completed using two replications each of three combinations of streamside buffer width and canopy retention level, and two unharvested controls. GPS positional data from the mobile harvesting equipment, along with the sediment delivery information, was analyzed in a geographic information system (GIS) in order to draw conclusions about the influences of buffer width, canopy retention level, and traffic intensity on delivery of sediment to headwater streams. Results indicate that increased forested buffer width correlates with reduced sediment delivery to stream channels.
The Journal of Asthma, Nov 18, 2002
In this analysis, we sought to determine factors that predicted the level of asthma knowledge in ... more In this analysis, we sought to determine factors that predicted the level of asthma knowledge in a sample of adolescents with asthma and their parents. Eighty-five young people aged 10-24 years attending tertiary care asthma clinics and 46 of their parents answered validated respiratory and asthma knowledge questionnaires. Older adolescents were more knowledgeable about asthma than were younger adolescents (r=0.36, p=0.001). Young people with severe asthma (p=0.015) scored higher on the asthma knowledge questionnaire than those with mild/moderate asthma. Asthma knowledge among young people was related to that of their mothers (r=0.47, p=0.014), however, only age and the asthma knowledge of fathers significantly predicted adolescent asthma knowledge. Adolescents develop increasing autonomy for asthma self-management as they mature, but parents remain an important source of information about asthma for young people.
Death Studies, Sep 28, 2011
A grounded theory study was undertaken to understand how general practitioners (GPs) experience t... more A grounded theory study was undertaken to understand how general practitioners (GPs) experience the death of their patients. Eleven GPs participated in semistructured interviews. The participants explained their experience of a patient's death using the "death journey" metaphor. This journey, the Journey with the Dying, could be described from 5 different moments in the participants' encounters with people who are dying: private acknowledgement, communication of prognosis, continuity of care, the moment of death, and looking after the family. Emotional responses for each of the stages, and coping strategies in general, were outlined. GPs' narratives about professional identity, learning about dying and death, and death beliefs were also important in the Journey with the Dying. The experience of death described by the GPs in this study was different from that reported by medical doctors in other care settings. The 5 phases of the Journey with the Dying identified here show the different adjustments and appraisals that GPs undertake to comprehend and to be able to work in the presence of death.
International Journal of Soil Sediment and Water, 2010
Due to their physical properties, illite clays can sorb cesium-137 almost irreversibly, and there... more Due to their physical properties, illite clays can sorb cesium-137 almost irreversibly, and therefore sequester contamination from the environment. However, applying large amounts of clay to natural aquatic habitats for in situ remediation purposes may create conditions of high turbidity and sedimentation. To evaluate potential effects of turbidity from illite application on survivorship of stream fish, yellowfin shiners (Notropis lutipinnis) and tessellated darters (Etheostoma olmstedi) were subjected to treatment with two different types of clay in flow-through simulated stream raceways. Turbidity and fish mortality were subsequently monitored for seven days. At 2-m downstream from the application point, mean turbidity peaked during clay application at 525 and 72 nephelometric turbidity units (NTU) in the air-floated illite and semi-dry illite treatments, respectively. Turbidity returned to levels similar to that of the controls (4-6 NTU) after four hours in the air-floated illite raceways and one hour in the semi-dry illite raceways. Although the majority of the suspended clay was quickly flushed from the system and the remaining settled to the bottom, turbidity did continue to fluctuate because of fish movements and sediment resuspension. Fish mortality did not significantly differ among control and illite treated raceways.
The Journal of Orthopaedic and Sports Physical Therapy, Sep 1, 2008
Journal of Environmental Quality, Mar 1, 2012
Surface mining is a common method for extracting coal in the coal fields of eastern Kentucky. Usi... more Surface mining is a common method for extracting coal in the coal fields of eastern Kentucky. Using the Forestry Reclamation Approach (FRA), which emphasizes the use of minimally compacted or loose-dumped spoil as a growth medium for trees, reclamation practitioners are successfully reestablishing forests. Yet, questions remain regarding the effects FRA has on the quality of waters discharged to receiving streams. To examine the effect of FRA on water quality, this study compared waters that were discharged from three types of spoils: predominantly brown, weathered sandstone (BROWN); predominantly gray, unweathered sandstone (GRAY); and an equal mixture of both aforementioned sandstones and shale (MIXED). The water quality parameters pH, EC, Ca, K, Mg, Na, NO-N, NH-N, SO, Cl, TC, suspended sediment concentration (SSC), settleable solids (SS), and turbidity were monitored over a 2-yr period on six 0.4-ha plots (two replications per spoil type). Generally, levels of Cl, SO, Ca, NO-N, NH-N, SS, SSC, and turbidity decreased over time. The pH for all spoils increased from about 7.5 to 8.5. The EC remained relatively level in the BROWN spoil, whereas the GRAY and MIXED spoils had downward trajectories that were approaching 500 μS cm. The value of 500 μS cm has been reported as the apparent threshold at which certain taxa such as Ephemeroptera (e.g., Mayfly) recolonize disturbed headwater streams of eastern Kentucky and adjacent coal-producing Appalachian states.
Biofuel plantations provide an opportunity to diversify and increase domestic energy feedstocks (... more Biofuel plantations provide an opportunity to diversify and increase domestic energy feedstocks (Johnson and others 2007). Currently, woody biomass is the leading domestic renewable energy supply and the U.S. Department of Energy forecasts an annual biomass supply of 1 billion tons by 2050 . Demand for woody biomass will be met through fuel reduction treatments, industrial waste residues, and reforestation projects (Perlack and others 2005). Woody crops intended for co-fi ring with coal for electricity generation will prolong coal supplies, reduce NO x and SO x emissions, and contribute to national woody feedstock supplies (Boylan 1996).
Critical Care Medicine, 1989
Capnography is a valuable tool in the management of cardiac arrest, since end-tidal CO2 (PetCO2) ... more Capnography is a valuable tool in the management of cardiac arrest, since end-tidal CO2 (PetCO2) correlates well with cardiac output and there are no other suitable noninvasive ways to measure this important variable during resuscitation. Animal studies also suggest that PetCO2 correlates well with the likelihood of resuscitation, but this has never been confirmed in humans. We prospectively studied 55 adult, nontraumatic prehospital cardiac arrest patients. PetCO2 was monitored with an in-line sensor on arrival in the ED and throughout the arrest, which was managed by the usual advanced cardiac life-support treatment guidelines. Chest compression was carried out mechanically. Patients were assessed for return of spontaneous pulse as evidence of initial resuscitation; hospital discharge and long-term survival were not examined. Fourteen patients developed spontaneous pulses and were resuscitated, and 41 were not. The length and aggressiveness of treatment and CPR were not different between the two groups, nor were there differences in down time, resuscitation time, or other factors known to affect outcome. Patients who developed a pulse had a mean PetCO2 of 19 +/- 14 (SD) torr at the start of resuscitation, and those who did not had a mean PetCO2 of 5 +/- 4 torr (p less than .0001). This difference was significant both in nonperfusing rhythms (asystole and ventricular fibrillation) and in potentially perfusing rhythms (electromechanical dissociation). An initial PetCO2 of 15 torr correctly predicted eventual return of pulse with a sensitivity of 71%, a specificity of 98%, a positive predictive value of 91%, and a negative predictive value of 91%. A receiver operating curve was generated for sensitivity and specificity of the test at varying PetCO2 thresholds.
Proceedings of the 2004 Conference of the Centre For Advanced Studies on Collaborative Research, 2004
Abstract Optimizing compilers can automatically re-arrange data objects to produce memory referen... more Abstract Optimizing compilers can automatically re-arrange data objects to produce memory reference patterns with better reference locality while retaining correct application semantics. This paper describes a new technique, Remote Field Cloning (RFC), that ...
Australian family physician
Progress in Palliative Care
Introduction: This study evaluated the use of a family meeting model to address the spiritual nee... more Introduction: This study evaluated the use of a family meeting model to address the spiritual needs of palliative patients and their family members in the context of two metropolitan palliative care (PC) services offering hospital, hospice, and home care. Murphy's family meeting model that incorporates a broad understanding of spirituality was utilized. Here we report the acceptability of this model to staff and patients in these settings. Methods: Qualitative methods, informed by an interpretive approach and underpinned by Hermeneutic phenomenology, were used to evaluate a trial of the family meeting model. Participants included 12 palliative patients and 35 family members. Twelve family meetings were facilitated, by the lead author (H.T.). Following each meeting individual in-depth interviews were conducted with consenting participants. Interviews were also held with 14 PC staff from a variety of disciplines, who had referred patients to the study. Transcribed interviews were analysed utilizing Ricoeur's theory of interpretation. Findings: Patients, family members, and staff indicated that participation in a family meeting of this type would be a valuable addition to regular PC services. However, practical barriers to its application were identified and included the need for specific meeting facilitation skills, funding priorities, staff time, and possible language and cultural issues. Conclusion: This model of family meeting is potentially a very useful intervention in a setting which promotes holistic care of patients and their family members, including attention to psychosocial and spiritual care. Strategies to overcome barriers to implementation such as time and cost issues need further investigation.
Progress in Palliative Care, 2011
Methods Qualitative methods, informed by an interpretive approach and underpinned by Hermeneutic ... more Methods Qualitative methods, informed by an interpretive approach and underpinned by Hermeneutic phenomenology, were used to evaluate a trial of the family meeting model. Participants included 12 palliative patients and 35 family members. Twelve family ...
Primary care respiratory journal : journal of the General Practice Airways Group, 2005
We investigated the attitudes of caregivers towards written asthma action plans (WAAPs). A small ... more We investigated the attitudes of caregivers towards written asthma action plans (WAAPs). A small number of caregivers participating in a larger randomised controlled trial (RCT) participated in qualitative interviews. 'Ownership and use of WAAPs' and 'Schools and WAAPs' were the main themes to emerge. The new school year is an opportunity to review and update WAAPs.
Primary care respiratory journal : journal of the General Practice Airways Group, 2004
Written asthma action plans (WAAPs) have become a core component of asthma management in Australi... more Written asthma action plans (WAAPs) have become a core component of asthma management in Australia. We investigated ownership, utilisation and factors associated with ownership of asthma action plans by caregivers. 443/776 (57%) caregivers of children aged 2-14 years with asthma were identified from 32 GP clinics as part of a randomised controlled trial (RCT), and completed self-administered questionnaires. Only 29% of participants owned a WAAP, while 13% possessed verbal instructions, and 56% had no plan. An asthma action plan for children, which was developed by a general practitioner (GP) was more likely to comprise verbal instructions (p = 0.001), while action plans developed by paediatricians were more likely to be written (p < 0.001). Just over one half of caregivers (59%) reported discussing their child's action plan the last time they visited their doctor for asthma. Factors associated with WAAP ownership included nights waking (p = 0.013), self reported severity (p =...
Australian family physician
Clinical audit is recognised worldwide as a useful tool for quality improvement. A feedback repor... more Clinical audit is recognised worldwide as a useful tool for quality improvement. A feedback report profiling capacity for chronic disease care was sent to 97 general practices. These practices were invited to complete a clinical audit activity based on that feedback. Data were analysed quantitatively and case studies were developed based on the free text responses. Eighty-two (33%) of 247 general practitioners participated in the clinical audit process, representing 57 (59%) of 97 general practices. From the data in their feedback report, 37 (65%) of the 57 practices recognised the area most in need of improvement. This was most likely where the need related to clinical practice or teamwork, and least likely where the need related to linkages with other services, and business and finance. Only 25 practices (46%) developed an action plan related to their recognised area for improvement, and 22 (39%) practices implemented their chosen activity. Participating GPs judged that change act...
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Papers by Christopher Barton