Publications by authors named "Lucia Ma"

7 Publications

  • Page 1 of 1

Comparison of long and short axis quantification of left ventricular volume parameters by cardiovascular magnetic resonance, with ex-vivo validation.

J Cardiovasc Magn Reson 2011 Aug 11;13:40. Epub 2011 Aug 11.

Stephenson Cardiovascular MR Centre at Libin Cardiovascular Institute of Alberta, Departments of Cardiac Sciences and Radiology, University of Calgary, AB, Canada.

Background: The purpose of the study was to compare the accuracy and evaluation time of quantifying left ventricular (LV), left atrial (LA) volume and LV mass using short axis (SAX) and long axis (LAX) methods when using cardiovascular magnetic resonance (CMR).

Materials And Methods: We studied 12 explanted canine hearts and 46 patients referred for CMR (29 male, age 47 ± 18 years) in a clinical 1.5 T CMR system, using standard cine sequences. In standard short axis stacks of various slice thickness values in dogs and 8 mm slice thickness (gap 2 mm) in patients, we measured LV volumes using reference slices in a perpendicular, long axis orientation using certified software. Volumes and mass were also measured in six radial long axis (LAX) views.LV parameters were also assessed for intra- and inter-observer variability. In 24 patients, we also analyzed reproducibility and evaluation time of two very experienced (> 10 years of CMR reading) readers for SAX and LAX.

Results: In the explanted dog hearts, there was excellent agreement between ex vivo data and LV mass and volume data as measured by all methods for both, LAX (r² = 0.98) and SAX (r² = 0.88 to 0.98). LA volumes, however, were underestimated by 13% using the LAX views. In patients, there was a good correlation between all three assessed methods (r² ≥ 0.95 for all). In experienced clinical readers, left-ventricular volumes and ejection fraction as measured in LAX views showed a better inter-observer reproducibility and a 27% shorter evaluation time.

Conclusion: When compared to an ex vivo standard, both, short axis and long axis techniques are highly accurate for the quantification of left ventricular volumes and mass. In clinical settings, however, the long axis approach may be more reproducible and more time-efficient. Therefore, the rotational long axis approach is a viable alternative for the clinical assessment of cardiac volumes, function and mass.
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http://dx.doi.org/10.1186/1532-429X-13-40DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169477PMC
August 2011

The discharge brunch: reducing chaos and increasing smiles on the OB unit.

Nurs Womens Health 2009 Oct;13(5):402-9

Martha Jefferson Hospital, Charlottesville, VA, USA.

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http://dx.doi.org/10.1111/j.1751-486X.2009.01458.xDOI Listing
October 2009

Transbronchial needle aspiration in diagnosing and staging lung cancer: how many aspirates are needed?

Am J Respir Crit Care Med 2002 Aug;166(3):377-81

Section of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1054, USA.

Transbronchial needle aspiration has emerged as a key technique for sampling mediastinal adenopathy but variable yields are reported. To determine the number of aspirates needed to optimize yield, we prospectively studied transbronchial needle aspiration and the sequential effect of each successive specimen on diagnostic yield in 79 patients with known or suspected lung carcinoma and mediastinal adenopathy. A total of 451 aspirates were performed in 79 patients (mean, 5.7 aspirates per patient; range, 2-13) with 45 cases (57%) positive for malignancy. A cytologically positive transbronchial needle aspiration occurred with the first aspirate in 42% of patients in whom this procedure established mediastinal nodal involvement. All positive results were achieved with seven or fewer aspirates. Similar yields were obtained for small cell and non-small cell lung cancer after seven aspirates. Rapid on-site specimen cytologic evaluation was used in 55 of 79 cases (70%), with a positive diagnosis obtained in 39 of 55 cases (71%) with on-site evaluation compared with six of 24 cases (25%) performed without on-site evaluation. The data suggest there is a plateau in yield after seven transbronchial needle aspirates, which may be sufficient to obtain an optimal yield in assessing patients with lung cancer and mediastinal adenopathy.
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http://dx.doi.org/10.1164/rccm.2106153DOI Listing
August 2002

Images in clinical medicine. Superficial thrombophlebitis.

Authors:
M A Lucia E W Ely

N Engl J Med 2001 Apr;344(16):1214

University of Nevada School of Medicine, Reno 89520-0111, USA.

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http://dx.doi.org/10.1056/NEJM200104193441605DOI Listing
April 2001

Predictors of successful extubation in neurosurgical patients.

Am J Respir Crit Care Med 2001 Mar;163(3 Pt 1):658-64

Department of Internal Medicine (Section of Pulmonary/Critical Care), Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina 27157, USA.

A respiratory therapist-driven weaning protocol incorporating daily screens, spontaneous breathing trials (SBT), and prompts to caregivers has been associated with superior outcomes in mechanically ventilated medical patients. To determine the effectiveness of this approach in neurosurgical (NSY) patients, we conducted a randomized controlled trial involving 100 patients over a 14-mo period. All had daily screens of weaning parameters. If these were passed, a 2-h SBT was performed in the Intervention group. Study physicians communicated positive SBT results, and the decision to extubate was made by the primary NSY team. Patients in the Intervention (n = 49) and Control (n = 51) groups had similar demographic characteristics, illness severity, and neurologic injuries. Among all patients, 87 (45 in the Control and 42 in the Intervention group) passed at least one daily screen. Forty (82%) patients in the Intervention group passed SBT, but a median of 2 d passed before attempted extubation, primarily because of concerns about the patient's sensorium (84%). Of 167 successful SBT, 126 (75%) did not lead to attempted extubation on the same day. The median time of mechanical ventilation was 6 d in both study groups, and there were no differences in outcomes. Overall complications included death (36%), reintubation (16%), and pneumonia (9%). Tracheostomies were created in 29% of patients. Multivariate analysis showed that Glasgow Coma Scale (GCS) score (p < 0.0001) and partial pressure of arterial oxygen/fraction of inspired oxygen ratio (p < 0.0001) were associated with extubation success. The odds of successful extubation increased by 39% with each GCS score increment. A GCS score > or = 8 at extubation was associated with success in 75% of cases, versus 33% for a GCS score < 8 (p < 0.0001). Implementation of a weaning protocol based on traditional respiratory physiologic parameters had practical limitations in NSY patients, owing to concerns about neurologic impairment. Whether protocols combining respiratory parameters with neurologic measures lead to superior outcomes in this population requires further investigation.
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http://dx.doi.org/10.1164/ajrccm.163.3.2003060DOI Listing
March 2001

The influence of wind and locomotor activity on surface temperature and energy expenditure of the Eastern house finch (Carpodacus mexicanus) during cold stress.

Physiol Biochem Zool 1999 May-Jun;72(3):265-76

Department of Biology, Colgate University, Hamilton, NY 13346, USA.

We investigated the extent to which exercise-generated heat compensates for regulatory thermogenesis of Eastern house finches (Carpodacus mexicanus Müller) exposed to ambient temperatures (Ta) and convective conditions typical of that which birds experience in nature while perched in the open or foraging on the ground. We addressed the hypothesis that resting and active birds exposed to similar net convective conditions will exhibit similar surface temperatures (Ts) and metabolic energy expenditures. To test this hypothesis, resting birds were exposed to a wind speed equivalent to the treadmill speed (0.5 m s-1) for a hopping bird (active). Ts of resting birds in no wind, resting birds exposed to wind, and active birds were measured with infrared thermography at Ta between 0 degrees and 25 degrees C. Metabolic heat production was estimated from measures of respiratory gases at Ta between -5 degrees and 25 degrees C. For resting birds in no wind, resting birds in wind, and active birds, Ts decreased with decreasing Ta. The effects of variation in Ta on Ts depended on activity level (F=3.91, df=2,40, P=0.0280). The regression relationship of Ts on Ta, however, did not differ significantly between resting birds exposed to wind and active birds (F=0.12, df=2,40, P=0.8865), whereas the slope was lower and intercept higher for resting birds in no wind compared with those of resting birds exposed to wind and active birds combined (F=20.96, df=2,42, P<0.0001). Metabolic heat production for resting birds exposed to wind and active birds increased with decreasing Ta. Average metabolic heat production of resting (46.01 mW g-1+/-10.60 SD) and active birds (47.63 mW g-1+/-8.76 SD) exposed to similar net convective conditions did not differ significantly (F=3.87, df=1,44, P=0.0556). These results support our hypothesis and provide evidence that exercise generated compensates for thermostatic requirements at Ta just below thermoneutrality, which resembles conditions under which house finches naturally forage. We conclude that the compensation of exercise-generated heat for regulatory thermogenesis may occur more frequently under natural environmental conditions than implied by most previous investigators and can result in considerable energy savings for birds living in cold environments.
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http://dx.doi.org/10.1086/316665DOI Listing
August 1999

Effect of drug-induced taurine depletion on cardiac contractility and metabolism.

Biochem Pharmacol 1986 Mar;35(6):985-9

Myocardial taurine content was halved in rats maintained for 3 weeks on tap water containing either 1% guanidinoethylsulfonate (GES) or 3% beta-alanine. The decrease in taurine content did not affect myocardial contraction; however, it significantly altered myocardial metabolism. The major effect of the treatment was a significant stimulation in the rate of glycolysis and lactate production. The rise in glycolytic flux was associated with activation of phosphofructokinase, presumably caused by a decrease in tissue citrate levels. GES-treated hearts also contained slightly lower creatine phosphate content, but since this effect was not observed in the beta-alanine-treated hearts, it appeared to be independent of taurine depletion. The consequences of these metabolic changes are discussed.
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http://dx.doi.org/10.1016/0006-2952(86)90087-0DOI Listing
March 1986
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