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James H Holmes

Publications and source records attributed to James H Holmes.

13 recordsLinked to original sources
PubMed2006

The effects of SNR on ADC measurements in diffusion-weighted hyperpolarized He-3 MRI.

The theoretical dependence of the mean and standard deviation of ADC values on signal-to-noise ratio (SNR) was derived and compared to measured values in porous phantoms and the lungs of human subjects using diffusion-weighted hyperpolarized helium-3 MRI. For SNR values below 15, mean ADC values were highly SNR-dependent due to a combination of noise and choice of noise thresholding. Above SNR values of 15 and for mean ADC values within ranges relevant for evaluating lung disease (<0.6 cm2/s), the mean ADC was largely independent of SNR. The standard deviation, by contrast, was highly dependent on SNR over a much larger range, but this dependence was well predicted by theory, suggesting the histogram of ADC values might be corrected for these stochastic processes to more accurately evaluate disease using restricted diffusion measures in the lungs.

Artifacts↗
PubMed2006

Impaired baseline regional cerebral perfusion in patients referred for coronary artery bypass.

BACKGROUND: Cognitive dysfunction and cerebral vascular accidents remain some of the most devastating problems related to cardiac surgery. Despite the major advances in perioperative care and operative technique in coronary artery bypass, this cohort of patients appears to have poor cerebral physiologic reserve. The aim of this study was to describe regional cerebral perfusion of patients with coronary artery disease referred for coronary artery bypass grafting. METHODS: Eighty-two consecutive patients with coronary artery disease referred for coronary artery bypass grafting were enrolled after providing informed consent in an institutional review board-approved study. Patients with prior cerebral vascular accident, transient ischemic attacks, head trauma, or other neurologic afflictions were excluded from the study. We prospectively measured preoperative regional cerebral perfusion using single photon emission computed tomography (SPECT) imaging of 12 regions. Patients were determined to have an abnormal SPECT if regional cerebral perfusion was less than 2 standard deviations below the mean of age-matched controls. RESULTS: The mean age was 67.5 (range, 34-89) years. The study group comprised 22% women and 78% men with known risk factors for atherosclerosis: current tobacco use (30%), hypertension (69%), and diabetes (27%). Seventy-five percent of the SPECT scans demonstrated abnormal regional cerebral perfusions, which were associated with older age (P < .008), current tobacco use (P < .005), and diabetes mellitus (P < .005). The incidence of postoperative cerebral vascular accident was 5% and only occurred in patients with abnormal regional cerebral perfusion. CONCLUSION: Seventy-five percent of patients undergoing coronary bypass grafting have a significant impairment in regional cerebral perfusion compared with published age-matched controls, which may contribute to their proclivity for cerebral complications.

Adult↗
PubMed2006

Fire and smoke injuries.

The successful management of burns and related injuries requires a comprehensive team approach at a designated burn center. This team should consist of burn surgeons, burn nurses, respiratory therapists, physical therapists, occupational therapists, clinical nutritionists, social workers, chaplains, and other clinical consultants. This article focuses specifically on the management of thermal burns and inhalational injuries, with an emphasis on assessment, resuscitation, and critical care management. It also discusses special considerations related to burned trauma patients.

Burns↗
PubMed2006

Timing of pulmonary emboli after trauma: implications for retrievable vena cava filters.

BACKGROUND: Four recent reports of the retrieval of optional vena cava filters (VCF) in trauma patients had average implant durations of 10, 19, and 19 days (one not specified). Two patients in these studies had pulmonary emboli after VCF removal. No evidence-based guidelines exist on the appropriate time to remove optional VCF. The purpose of this study was to examine the timing of pulmonary emboli (PE) and determine the optimal time to remove optional VCFs. METHODS: A multicenter retrospective chart review of trauma patients who had a postinjury PE between January 2001 and December 2004 was performed. We examined the demographics, prophylaxis at the time of PE (pharmacologic [unfractionated or low molecular weight heparin] or sequential compression devices [SCD]), diagnostic test used, timing of PE from the date of injury, and survival outcome. RESULTS: In all, 146 patients were identified, mean age 45.1 (+/- 21.1 SD); Injury Severity Score 18.0 (+/- 12.1 SD). Diagnosis was obtained by spiral computed tomography (N = 93), pulmonary arteriogram (N = 18), V/Q (N = 26), autopsy (N = 6), clinical (N = 6), and unknown (N = 3). Overall mortality was 17.8% (N = 26). Pulmonary embolism was felt to contribute to or was the cause of death in 85% (N = 22) of these patients. Two late PE deaths occurred (days 21 and 43). Sixty (37%) patients had pharmacologic prophylaxis at the time of PE and 83 (50.9%) had SCDs. Average time from injury to PE was 7.9 days (+/- 8.1 SD), the longest being 43 days postinjury. Eleven percent of PE occurred after 21 days, including fatal PE. CONCLUSIONS: Clinical criteria defining the time to remove optional VCFs without exposing patients to the risk of PE by removing a filter too soon should be determined.

Humans↗
PubMed2006

Timeline to operative intervention for solid organ injuries in children.

BACKGROUND: Nonoperative management of solid organ injuries (SOI) in children is now the standard of care. Little is know regarding the time to failure for those children requiring operative intervention. We sought to delineate this timeline to operative intervention for the subset of single solid organ injured patients requiring laparotomy. METHODS: The National Trauma Data Bank (NTDB) was queried for the period 1991 to 2003 for all children (age <15) with a single abdominal SOI (kidney, liver, spleen). Children with significant associated head injury (Abbreviated Injury Score; AIS >2) were excluded. Data abstracted included age, organ injury and severity (ICD-9, AIS), and operative procedures. Survival analysis methods were used to evaluate equality of hazard rates (indicating rate of operative intervention by hour). RESULTS: For the period of review, the NTDB contained 2,013 children with a single SOI including 1,813 eligible for review. The mean age was 9.2 +/- 3.8 years with a mean Injury Severity Score (ISS) of 8.6 +/- 6.3. The study population included 224 (12.4%) kidney injuries, 488 (26.9%) liver injuries, and 1,101 (60.7%) splenic injuries. A total of 120 (6.6%) of the patients required an operation for their solid organ injury. The median time to operation was 2.4 hours with 61.7% undergoing surgery within 3 hours of arrival, 79.4% within 6 hours, and 89.7% within 24 hours. The operative intervention rate was greatest for splenic injuries (8.7%) followed by liver (3.5%) and kidney (3.1%) injuries. Hazard rates varied significantly by organ injured (p < 0.001) and peaked at 1.5 hours for liver, 2 hours for spleen, and 4.5 hours for kidney. Hazard rates varied significantly by injury severity (p < 0.001) with a peak time to surgery for all severity at 2 hours postadmission. CONCLUSION: Although the patterns for peak time to operative intervention varied for the specific organs injured and injury severity, the need for operative intervention for children with an SOI is established for the vast majority of children within 24 hours of admission.

Abbreviated Injury Scale↗
PubMed2006

Early emphysematous changes in asymptomatic smokers: detection with 3He MR imaging.

PURPOSE: To prospectively compare apparent diffusion coefficient (ADC) measurements derived from diffusion-weighted hyperpolarized helium 3 (3He) magnetic resonance (MR) imaging with functional and structural findings using spirometric tests and thin-section computed tomography (CT) of the lungs in asymptomatic smokers and healthy nonsmokers of similar age. MATERIALS AND METHODS: All studies were HIPAA compliant and were approved by the institutional review board. Informed consent was obtained. Ventilation and diffusion-weighted 3He MR images were obtained in healthy subjects: 11 smokers (five women, six men; mean age, 47 years+/-18 [standard deviation]; range, 23-73 years) and eight nonsmokers (<100 cigarettes in lifetime) (four women, four men; mean age, 46 years+/-16; range, 23-69 years). Mean ADC values for smokers and nonsmokers were compared with spirometric values, diffusing capacity of the lung for carbon monoxide (Dlco), age, and pack-years with Spearman rank correlation coefficient (rs) and multiple linear regression analysis. Mean ADC value and thin-section CT emphysema index of relative area less than -950 HU (RA950) were compared on a regional basis by using linear mixed-effect models. RESULTS: Mean ADC values and number of pack-years were significantly correlated (rs=0.60; 95% confidence interval (CI): 0.21, 1.00; P=.007); relationship remained significant after adjustment for age (P=.003). Dlco was strongly correlated with pack-years (rs=-0.63; 95% CI: -0.97, -0.29; P=.004). Negative correlations between mean ADC values and percentage predicted Dlco (rs=-0.79; 95% CI: -0.93, -0.64; P<.001) and the ratio of forced expiratory volume in 1 second to forced vital capacity (rs=-0.72; 95% CI: -0.92, -0.52; P=.001) were statistically significant. Correlations between spirometric values or RA950 and number of pack-years were not significant (.05 level). CONCLUSION: Correlations between mean ADC values and pulmonary function test measurements for diagnosing emphysema, especially Dlco, were statistically significant.

Adolescent↗
PubMed2005

Noninvasive mapping of regional response to segmental allergen challenge using magnetic resonance imaging and [F-18]fluorodeoxyglucose positron emission tomography.

Magnetic resonance (MR) and positron emission tomography (PET) imaging techniques were coregistered to demonstrate regional ventilation and inflammation in the lung for in vivo, noninvasive evaluation of regional lung function associated with allergic inflammation. Four Brown Norway rats were imaged pre- and post segmental allergen challenge using respiratory-gated He-3 magnetic resonance imaging (MRI) to visualize ventilation, T(1)-weighted proton MRI to depict inflammatory infiltrate, and [F-18]fluorodeoxyglucose-PET to detect regional glucose metabolism by inflammatory cells. Segmental allergen challenges were delivered and the pre- and postchallenge lung as well as the contralateral lung were compared. Coregistration of the imaging results demonstrated that regions of ventilation defects, inflammatory infiltrate, and increased glucose metabolism correlated well with the site of allergen challenge delivery and inflammatory cell recruitment, as confirmed by histology. This method demonstrates that fusion of functional and anatomic PET and MRI image data may be useful to elucidate the functional correlates of inflammatory processes in the lungs.

Allergens↗
PubMed2005

Management of facial burns with a collagen/glycosaminoglycan skin substitute-prospective experience with 12 consecutive patients with large, deep facial burns.

Management of deep facial burns remains one of the greatest challenges in burn care. We have developed a protocol over the past 20 years for management of facial burns that includes excision and coverage with thick autograft. However, the results were not perfect. Deformities of the eyelids, nose and mouth as well as the prominence of skin graft junctures demonstrated the need to explore novel approaches. Integra has been used with success in the management of burns of the trunk and extremities. The purpose of this study was to prospectively evaluate the aesthetic outcome of the use of Integra for deep facial burns. Twelve consecutive patients underwent excision of large, deep facial burns and placement of Integra. Integra provides excellent color and minimally visible skin graft junctures. The texture is good but not as supple as thick autograft. Integra is not well suited for use in the coverage of eyelid burns due to the need to wait 2 weeks for adequate vascularization. In summary, thick autograft remains the gold standard for deep facial burns. However, for patients with extensive burns and limited donor sites, Integra provides an acceptable alternative.

Adult↗
PubMed2005

The failure of nonoperative management in pediatric solid organ injury: a multi-institutional experience.

BACKGROUND: Nonoperative management (NOM) is the accepted treatment of most pediatric solid organ injuries (SOI) and, is typically successful. We sought to elucidate predictors of, and the time course to, failure in the subset of children suffering SOI who required operative intervention. METHODS: A retrospective analysis was performed from January 1997 through December 2002 of all pediatric patients (age 0-20 years) with a SOI (liver, spleen, kidney, pancreas) from the trauma registries of seven designated, level I pediatric trauma centers. Failure of NOM was defined as the need for intra-abdominal operative intervention. Data reviewed included demographics, injury mechanism, injury severity (ISS, AIS, SOI grade, and GCS), and outcome. For the failures of NOM, time to operation and relevant clinical variables were also abstracted. A summary AIS (sAIS) was calculated for each patient by summing the AIS values for each SOI, to account for multiple SOI in the same patient. Univariate and multivariate analyses were employed, and significance was set at p < 0.05. RESULTS: A total of 1,880 children were identified. Of these, 62 sustained nonsurvivable head injuries that precluded assessment of NOM outcome and were thus excluded. The remaining 1,818 patients comprised the overall study population. There were 1,729 successful NOM patients (controls -- C) and 89 failures (F), for an overall NOM failure rate of 5%. For isolated organ injuries, the failure rates were: kidney 3%, liver 3%, spleen 4%, and pancreas 18%. There were 14 deaths in the failure group from nonsalvageable injuries (mean ISS = 54 +/- 15). The two groups did not differ with respect to mean age or gender. An MVC was the most common injury mechanism in both groups. Only bicycle crashes were associated with a significantly increased risk of failing NOM (RR = 1.76, 95% CI = 1.02-3.04, p < 0.05). Injury severity and organ specific injuries were associated with NOM failure. When controlling for ISS and GCS, multivariate regression analysis confirmed that a sAIS > or = 4, isolated pancreatic injury, and >1 organ injured were significantly associated with NOM failure (p < 0.01). The median time to failure was 3 hours (range, 0.5-144 hours) with 38% having failed by 2 hours, 59% by 4 hours, and 76% by 12 hours. CONCLUSIONS: Failure of NOM is un common (5%) and typically occurs within the first 12 hours after injury. Failure is associated with injury severity and multiplicity, as well as isolated pancreatic injuries.

Adolescent↗
PubMed2004

Isoindolinone ureas: a novel class of KDR kinase inhibitors.

A series of substituted isoindolinone ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 14c, are potent inhibitors of KDR both enzymatically (< 50 nM) and cellularly < or = 100 nM). A 3D KDR/CDK2/MAP kinase overlay model with several structurally related tyrosine kinase inhibitors was used to predict the binding interactions of the isoindolinone ureas with the KDR active site.

Animals↗
PubMed2002

Natural history of traumatic rupture of the thoracic aorta managed nonoperatively: a longitudinal analysis.

BACKGROUND: Although traumatic rupture of the thoracic aorta (TRA) has traditionally been considered a surgical emergency, there exists a small patient population for whom nonoperative management may be appropriate. The short- and long-term consequences of patients managed in a nonoperative fashion remain unclear. METHODS: A review of patients admitted with TRA over a period of 16 years was performed. Patients who did not undergo operative repair within 24 hours of injury and diagnosis comprised the study group. RESULTS: One hundred forty-five patients were admitted with TRA. Of these, 30 underwent a period of nonoperative management. The mean age of the study patients was 44 +/- 21 years, 80% were male, and the mean Injury Severity Score (ISS) was 34 +/- 9. Fifteen patients underwent delayed operation (DELAY group) at more than 24 hours after injury and diagnosis and 15 patients never underwent repair (NON-OP group). The median time to operation in the DELAY group was 3 days (range 2 to 90). Three patients exhibited progression of TRA within 5 days of injury and of these, 2 died. A total of 3 deaths occurred in the DELAY group (1 rupture and 2 intraoperative arrests). The fifteen NON-OP patients were significantly older (mean age 52 +/- 22 versus 36 +/- 18 years; p = 0.03), tended to be more severely injured (mean ISS 36 +/- 9 versus 32 +/- 8; p = 0.2), and had more premorbid risk factors than the DELAY patients. Five NON-OP patients died, all because of severe head injuries. On long-term follow-up of NON-OP patients, all 10 survivors are alive at a median of 2.5 years (range 6 months to 5 years) without progression of injury or the need for operation. Five of the 10 had complete radiographic resolution of their injuries and 5 have asymptomatic and radiographically stable pseudoaneurysms. CONCLUSIONS: Selected patients with multiple severe associated injuries or high-risk premorbid conditions may have their operations for TRA delayed temporarily or even indefinitely with acceptable survival rates. The potential for rapid progression of TRA in the same patients, however, mandates serial radiographic examinations during the first week of hospitalization after injury and diagnosis.

Adult↗
PubMedDate not supplied

SCORTEN overestimates mortality in the setting of a standardized treatment protocol.

Toxic epidermal necrolysis (TEN) is a rare, severe, exfoliative disorder with a high mortality rate. SCORTEN is a recently developed scoring system that estimates severity and predicts mortality in patients with TEN based on seven independent clinical risk factors recorded within the first 24 hours of admission. An increasing SCORTEN level predicts a higher mortality rate. For more than 20 years, the treatment of TEN at our institution has involved the use of a standardized clinical pathway that includes removal of sloughed epidermis, dermal protection with porcine xenograft, early enteral nutrition, and critical care monitoring. We hypothesize that this standardized clinical approach will result in a lower mortality rate than predicted by SCORTEN. A retrospective review was performed on all patients treated for TEN using the standardized pathway from February 1987 to March 2004. SCORTEN was calculated in each patient. One hundred nine patients were treated for TEN during the study period. Overall observed mortality was 20% compared with a SCORTEN predicted mortality of 30%, resulting in a relative reduction in mortality of 33% (P = .011). In addition, observed probability of death was lower than predicted at all levels, except at SCORTEN score of 6 or greater. In conclusion, TEN remains a life-threatening disease with a high mortality rate. Our standardized treatment protocol results in significantly improved outcomes compared to those predicted by SCORTEN.

Adult↗