Search PubMed⌕ Search

Biomedical subjects

Hilaire J Thompson

Publications and source records attributed to Hilaire J Thompson.

17 recordsLinked to original sources
PubMed2006

Traumatic injury in the older adult from head to toe.

This review demonstrates essential issues to consider when caring for older trauma patients, including baseline physical status, mental health, comorbidities, and risk factors for sequelae and future injuries. The impact of a traumatic injury on older adults is complex. Issues of normal aging, functional status, chronic health conditions, and response to treatment affect health care and related decisions. Studies that have examined outcomes for older trauma patients to date have been mainly descriptive or confined to a single institution, limiting our ability to generalize. Other studies, using large data sets, have provided some information regarding possible primary prevention strategies, yet have limitations in the individual level detail collected. Nevertheless, this review also demonstrates the dearth of available evidence-based recommendations that provides support to treatment protocols in this complex and diverse patient population. The lack of an evidence base to use in the management of older trauma patients demonstrates the critical need for research in this rapidly growing population. An example of one such area includes the use of pulmonary artery catheters in older trauma patients. Although evidence to date suggests that pulmonary artery catheters are of benefit in the management of patients with physiologic compromise, it is unclear whether using these published cardiac output management recommendations leads to improved outcomes. In light of newly published data suggesting equivocal benefit from use of pulmonary artery catheters, with increased side effects, this controversy is an important area for future research. Critical care nurses, with their emphasis on multidisciplinary, holistic practice, can expand their influence as essential members of the interdisciplinary team caring for older trauma patients by cultivating geriatric specialty knowledge. Older trauma patients would benefit greatly from this type of specialty nursing care during all phases of the recovery trajectory, particularly in terms of adequate symptom management and prevention of sequelae, as well as with timely and appropriate initiation of consultative services. Using the intersection of primary and secondary prevention as the overall guide for practice, critical care nurses and other health care providers who possess an understanding of aging processes and comorbid conditions can significantly improve outcomes for older adults with traumatic injuries.

Age Factors↗
PubMed2006

Acute, transient hemorrhagic hypotension does not aggravate structural damage or neurologic motor deficits but delays the long-term cognitive recovery following mild to moderate traumatic brain injury.

OBJECTIVES: Posttraumatic hypotension is believed to increase morbidity and mortality in traumatically brain-injured patients. Using a clinically relevant model of combined traumatic brain injury with superimposed hemorrhagic hypotension in rats, the present study evaluated whether a reduction in mean arterial blood pressure aggravates regional brain edema formation, regional cell death, and neurologic motor/cognitive deficits associated with traumatic brain injury. DESIGN: Experimental prospective, randomized study in rodents. SETTING: Experimental laboratory at a university hospital. SUBJECTS: One hundred nineteen male Sprague-Dawley rats weighing 350-385 g. INTERVENTIONS: Experimental traumatic brain injury of mild to moderate severity was induced using the lateral fluid percussion brain injury model in anesthetized rats (n = 89). Following traumatic brain injury, in surviving animals one group of animals was subjected to pressure-controlled hemorrhagic hypotension, maintaining the mean arterial blood pressure at 50-60 mm Hg for 30 mins (n = 47). The animals were subsequently either resuscitated with lactated Ringer's solution (three times shed blood volume, n = 18) or left uncompensated (n = 29). Other groups of animals included those with isolated traumatic brain injury (n = 34), those with isolated hemorrhagic hypotension (n = 8), and sham-injured control animals receiving anesthesia and surgery alone (n = 22). MEASUREMENTS AND MAIN RESULTS: The withdrawal of 6-7 mL of arterial blood significantly reduced mean arterial blood pressure by 50% without decreasing arterial oxygen saturation or Pao2. Brain injury induced significant cerebral edema (p < .001) in vulnerable brain regions and cortical tissue loss (p < .01) compared with sham-injured animals. Neither regional brain edema formation at 24 hrs postinjury nor the extent of cortical tissue loss assessed at 7 days postinjury was significantly aggravated by superimposed hemorrhagic hypotension. Brain injury-induced neurologic deficits persisted up to 20 wks after injury and were also not aggravated by the hemorrhagic hypotension. Cognitive dysfunction persisted for up to 16 wks postinjury. The superimposition of hemorrhagic hypotension significantly delayed the time course of cognitive recovery. CONCLUSIONS: A single, acute hypotensive event lasting 30 mins did not aggravate the short- and long-term structural and motor deficits but delayed the speed of recovery of cognitive function associated with experimental traumatic brain injury.

Animals↗
PubMed2006

Traumatic brain injury in older adults: epidemiology, outcomes, and future implications.

Traumatic brain injury (TBI) is a significant problem in older adults. In persons aged 65 and older, TBI is responsible for more than 80,000 emergency department visits each year; three-quarters of these visits result in hospitalization as a result of the injury. Adults aged 75 and older have the highest rates of TBI-related hospitalization and death. Falls are the leading cause of TBI for older adults (51%), and motor vehicle traffic crashes are second (9%). Older age is known to negatively influence outcome after TBI. Although geriatric and neurotrauma investigators have identified the prognostic significance of preadmission functional ability, comorbidities, sex, and other factors such as cerebral perfusion pressure on recovery after illness or injury, these variables remain understudied in older adults with TBI. In the absence of good clinical data, predicting outcomes and providing care in the older adult population with TBI remains problematic. To address this significant public health issue, a refocusing of research efforts on this population is justified to prevent TBI in the older adult and to discern unique care requirements to facilitate best patient outcomes.

Aged↗
PubMed2006

From bedside to bench and back again: research issues in animal models of human disease.

To improve outcomes for patients with many serious clinical problems, multifactorial research approaches by nurse scientists, including the use of animal models, are necessary. Animal models serve as analogies for clinical problems seen in humans and must meet certain criteria, including validity and reliability, to be useful in moving research efforts forward. This article describes research considerations in the development of rodent models. As the standard of diabetes care evolves to emphasize intensive insulin therapy, rates of severe hypoglycemia are increasing among patients with type 1 and type 2 diabetes mellitus. A consequence of this change in clinical practice is an increase in rates of two hypoglycemia-related diabetes complications: hypoglycemia-associated autonomic failure (HAAF) and resulting hypoglycemia unawareness. Work on an animal model of HAAF is in an early developmental stage, with several labs reporting different approaches to model this complication of type 1 diabetes mellitus. This emerging model serves as an example illustrating how evaluation of validity and reliability is critically important at each stage of developing and testing animal models to support inquiry into human disease.

Animal Experimentation↗
PubMed2006

A feasibility study of methodological issues and short-term outcomes in seriously injured older adults.

BACKGROUND: For any given traumatic injury, older adults experience a longer hospitalization, more complications, and higher mortality than do younger patients. OBJECTIVES: To prospectively identify problems in designing follow-up studies in seriously injured older adults without head injury and to examine outcomes after serious trauma in older adults who were sent to a level I trauma center. METHODS: A short-term descriptive follow-up design was used in which each patient served as his or her baseline. Eligible patients had injuries that required admission to an intensive care unit, a hospital length of stay longer than 72 hours, or surgery. Patients with isolated hip fractures, central nervous system injuries, and burn injuries were excluded. Data were collected by using standardized instruments during the acute hospital stay and 3 months after discharge from the hospital. RESULTS: During a representative 2-month period, 21% of a potential 77 subjects died in the hospital, 44% had cognitive impairment that precluded participation, and 17% declined to participate. Twenty older adults (mean age 73.5 years) who were injured in motor vehicle crashes (45%), falls (35%), or pedestrian accidents (15%) or who had gunshot wounds (5%) were enrolled. Ten percent died after discharge. Levels of physical disability at 3 months after discharge were higher than those before the injury (score on Sickness Impact Profile physical subscale 24.5 vs 10.9, P = .02), and psychological distress (Impact of Event Scale score 20.9) remained elevated. CONCLUSION: Mortality, disability, and posttraumatic psychological distress after discharge are problems in seriously injured older adults.

Age Factors↗
PubMed2006

Cognitive evaluation of traumatically brain-injured rats using serial testing in the Morris water maze.

PURPOSE: As deficits in memory and cognition are commonly observed in survivors of traumatic brain injury (TBI), causing reduced quality of life for the patient, a major goal in experimental TBI research is to identify and evaluate cognitive dysfunction. The present study assessed the applicability of the serial Morris water maze (MWM) test to determine cognitive function following experimental TBI in the same group of rats which is particularly important for long-term studies and increasingly valuable for the evaluation of novel treatment strategies. METHODS: Male Sprague-Dawley rats (n = 27) were anesthetized and subjected to either sham injury (n = 9) or lateral fluid percussion (FP) brain injury of moderate severity (n = 18). At 4 weeks post-injury, animals were trained in a water maze over 3 days (acquisition/learning phase) to find a submerged platform. At 8 weeks post-injury the hidden platform was then moved to the opposite quadrant, and animals were trained to find the new position of the platform over 3 days. Forty-eight hours later, animals were tested for memory retention in a probe trial in which the platform was not present. RESULTS: Brain-injured animals had significant learning impairment (p < 0.0001), shifted-learning impairment (p < 0.001) and memory retention deficits (p < 0.01) in comparison to their sham-injured counterparts over the 8 week testing period. Swim speed and distance were not significantly altered by brain injury at any time point. CONCLUSION: The validation of this testing paradigm using a clinically relevant experimental brain injury model is an important addition to behavioral outcome testing.

Animals↗
PubMed2005

Development of posttraumatic hyperthermia after traumatic brain injury in rats is associated with increased periventricular inflammation.

Posttraumatic hyperthermia (PTH) is a noninfectious elevation in body temperature that negatively influences outcome after traumatic brain injury (TBI). We sought to (1) characterize a clinically relevant model and (2) investigate potential cellular mechanisms of PTH. In study I, body temperature patterns were analyzed for 1 week in male rats after severe lateral fluid percussion (FP) brain injury (n=75) or sham injury (n=17). After injury, 27% of surviving animals experienced PTH, while 69% experienced acute hypothermia with a slow return to baseline. A profound blunting or loss of circadian rhythmicity (CR) that persisted up to 5 days after injury was experienced by 75% of brain-injured animals. At 2 and 7 days after injury, patterns of cell loss and inflammation were assessed in selected brain thermoregulatory and circadian centers. Significant cell loss was not observed, but PTH was associated with inflammatory changes in the hypothalamic paraventricular nucleus (PVN) by one week after injury. In brain-injured animals with altered CR, reactive astrocytes were bilaterally localized in the suprachiasmatic nucleus (SCN) and the PVN. Occasional IL-1beta+/ED-1+ macrophages/microglia were observed in the PVN and SCN exclusively in brain-injured animals developing PTH. In animals with PTH there was a significant positive correlation (r=0.788, P<0.01) between the degree of postinjury hyperthermia and the total number of cells positive for inflammatory markers within selected thermoregulatory and circadian nuclei. In study II, a separate group of animals underwent the same injury and temperature monitoring paradigm as in study I, but had additional physiologic data obtained, including vital signs, arterial blood gases, white blood cell counts, and C-reactive protein levels. All parameters remained within normal ranges after injury. These data suggest that PTH and the alteration in CR of temperature may be due, in part, to acute reactive astrocytosis and inflammation in hypothalamic centers responsible for both thermoregulation and CR.

Animals↗
PubMed2005

Lateral fluid percussion brain injury: a 15-year review and evaluation.

This article comprehensively reviews the lateral fluid percussion (LFP) model of traumatic brain injury (TBI) in small animal species with particular emphasis on its validity, clinical relevance and reliability. The LFP model, initially described in 1989, has become the most extensively utilized animal model of TBI (to date, 232 PubMed citations), producing both focal and diffuse (mixed) brain injury. Despite subtle variations in injury parameters between laboratories, universal findings are evident across studies, including histological, physiological, metabolic, and behavioral changes that serve to increase the reliability of the model. Moreover, demonstrable histological damage and severity-dependent behavioral deficits, which partially recover over time, validate LFP as a clinically-relevant model of human TBI. The LFP model, also has been used extensively to evaluate potential therapeutic interventions, including resuscitation, pharmacologic therapies, transplantation, and other neuroprotective and neuroregenerative strategies. Although a number of positive studies have identified promising therapies for moderate TBI, the predictive validity of the model may be compromised when findings are translated to severely injured patients. Recently, the clinical relevance of LFP has been enhanced by combining the injury with secondary insults, as well as broadening studies to incorporate issues of gender and age to better approximate the range of human TBI within study design. We conclude that the LFP brain injury model is an appropriate tool to study the cellular and mechanistic aspects of human TBI that cannot be addressed in the clinical setting, as well as for the development and characterization of novel therapeutic interventions. Continued translation of pre-clinical findings to human TBI will enhance the predictive validity of the LFP model, and allow novel neuroprotective and neuroregenerative treatment strategies developed in the laboratory to reach the appropriate TBI patients.

Animals↗
PubMed2005

Not your "typical patient": cryptococcal meningitis in an immunocompetent patient.

Meningitis, when caused by the fungal mycoses Cryptococcus neoformans, is normally seen in immuno-compromised hosts. However, immunocompetent patients are also susceptible to cryptococcal meningitis (CM). In patients with an intact immune system, CM usually presents with the typical signs and symptoms of meningitis: fever, stiff neck, and headache. Major implications for the primary and advanced practice nursing plans of care for CM patients include a thorough history and physical exam, early diagnosis and treatment, and an individualized plan of care focused on minimizing sequelae and side effects of treatment and maximizing functional recovery.

Amphotericin B↗
PubMed2005

Fever: a concept analysis.

AIM: The purpose of this paper is to critically analyse the current state of the science literature in order to develop an accurate conception of fever. RATIONALE: The measurement of body temperature and treatment of fever have long been considered to be within the domain of nursing practice. What body temperature constitutes 'fever', however, is often not clear from nursing protocols or the literature. METHODS: Literature for this concept analysis was obtained by computerized searches of PubMed, CINAHL and BIOSYS for the years 1980-2004. Additional sources were obtained after reviewing the bibliographies of the literature identified by the initial search. The Wilsonian method of concept analysis provided the framework for the analysis. FINDINGS: Fever has characteristically been recognized as a cardinal sign of illness and has traditionally had negative connotations for patient well-being. Substantive advances over the past 20 years in immunology and neurophysiology have expanded understanding of the process of fever. This new knowledge has shifted the perception of fever as part of the acute-phase response to one of an adaptive nature. This knowledge has yet to be fully translated into changes in the fever management practices of nurses. CONCLUSIONS: Consistent usage of terminology in relation to fever should lead to improved and evidence-based care for patients, and to fever management practices consistent with current research. It is important to use clear language about fever and hyperthermia in discussions and documentation between nurses and among disciplines. By creating clarity in our language, we may help to achieve praxis.

Anxiety↗
PubMed2004

Differential effects of the anticonvulsant topiramate on neurobehavioral and histological outcomes following traumatic brain injury in rats.

The efficacy of topiramate, a novel therapeutic agent approved for the treatment of seizure disorders, was evaluated in a model of traumatic brain injury (TBI). Adult male rats were anesthetized (sodium pentobarbital, 60 mg/kg, i.p.), subjected to lateral fluid percussion brain injury (n = 60) or sham injury (n = 47) and randomized to receive either topiramate or vehicle at 30 min (30 mg/kg, i.p.), and 8, 20 and 32 h postinjury (30 mg/kg, p.o.). In Study A, memory was evaluated using a Morris water maze at 48 h postinjury, after which brain tissue was evaluated for regional cerebral edema. In Study B, animals were evaluated for motor function at 48 h and 1, 2, 3, and 4 weeks postinjury using a composite neuroscore and the rotating pole test and for learning ability at 4 weeks. Brains were analyzed for hemispheric tissue loss and hippocampal CA3 cell loss. Topiramate had no effect on posttraumatic cerebral edema or histologic damage when compared to vehicle. At 48 h, topiramate treatment improved memory function in sham but not brain-injured animals, while at one month postinjury it impaired learning performance in brain-injured but not sham animals. Topiramate significantly improved composite neuroscores at 4 weeks postinjury and rotating pole performance at 1 and 4 weeks postinjury, suggesting a potentially beneficial effect on motor function following TBI.

Animals↗
PubMed2004

Ex vivo gene therapy using targeted engraftment of NGF-expressing human NT2N neurons attenuates cognitive deficits following traumatic brain injury in mice.

Infusion of nerve growth factor (NGF) has been shown to be neuroprotective following traumatic brain injury (TBI). In this study, we tested the hypothesis that NGF-expressing human NT2N neurons transplanted into the basal forebrain of brain-injured mice can attenuate long-term cognitive dysfunction associated with TBI. Undifferentiated NT2 cells were transduced in vitro with a lentiviral vector to release NGF, differentiated into NT2N neurons by exposure to retinoic acid and transplanted into the medial septum of mice 24 h following controlled cortical impact (CCI) brain injury or sham injury. Adult mice (n = 78) were randomly assigned to one of four groups: (1) sham-injured and vehicle (serum-free medium)-treated, (2) brain-injured and vehicle-treated, (3) brain-injured engrafted with untransduced NT2N neurons, and (4) brain-injured engrafted with transduced NGF-NT2N neurons. All groups were immunosuppressed daily with cyclosporin A (CsA) for 4 weeks. At 1 month post-transplantation, animals engrafted with NGF-expressing NT2N neurons showed significantly improved learning ability (evaluated with the Morris water maze) compared to brain-injured mice receiving either vehicle (p < 0.05) or untransduced NT2N neurons (p < 0.01). No effect of NGF-secreting NT2N cells on motor function deficits at 1-4 weeks post-transplantation was observed. These data suggest that NGF gene therapy using transduced NT2N neurons (as a source of delivery) may selectively improve cognitive function following TBI.

Animals↗
PubMed2003

Hyperthermia following traumatic brain injury: a critical evaluation.

Hyperthermia, frequently seen in patients following traumatic brain injury (TBI), may be due to posttraumatic cerebral inflammation, direct hypothalamic damage, or secondary infection resulting in fever. Regardless of the underlying cause, hyperthermia increases metabolic expenditure, glutamate release, and neutrophil activity to levels higher than those occurring in the normothermic brain-injured patient. This synergism may further compromise the injured brain, enhancing the vulnerability to secondary pathogenic events, thereby exacerbating neuronal damage. Although rigorous control of normal body temperature is the current standard of care for the brain-injured patient, patient management strategies currently available are often suboptimal and may be contraindicated. This article represents a compendium of published work regarding the state of knowledge of the relationship between hyperthermia and TBI, as well as a critical examination of current management strategies.

Animals↗