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Biomedical subjects

D E Morgan

Publications and source records attributed to D E Morgan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Practical imaging in acute pancreatitis.

Pancreatitis may be acute or chronic, mild or severe. In patients with acute pancreatitis the optimal imaging test is dynamic intravenous and oral contrast enhanced computed tomography (CECT). Serial CECTs are useful to monitor disease progression and to assess intraabdominal complications in patients with severe acute pancreatitis. CECT is helpful in planning the approach (endoscopic transmural versus percutaneous) for pancreatic drainage. Computed tomography or ultrasound-guided aspiration of pancreatic collections is safe, sensitive, and specific and has become a routine procedure used to screen for infected necrosis. When pancreatic drainage is contemplated, magnetic resonance imaging is useful for identifying residual necrotic debris within the collection. Patients with mild acute pancreatitis usually require no cross-sectional imaging study other than ultrasound screening for gallstones, if gallstone pancreatitis is suspected clinically. In patients with chronic pancreatitis, screening for complications such as superimposed acute pancreatitis or development of pancreatic pseudocysts may be performed with CECT or ultrasound.

Adult↗
PubMed1998

Pancreatic fluid collections: diagnosis and endoscopic management.

Pancreatitis may be acute or chronic, mild or severe. Acute necrotizing pancreatitis remains the most serious form of acute pancreatitis and accounts for the majority of complications. Although there is an established nomenclature for pancreatitis and pancreatic fluid collections, such as pancreatic pseudocysts, it is not widely understood or recognized by gastroenterologists. Because the management options for the treatment of pancreatic fluid collections continues to evolve with an increased use of endoscopic therapy, gastroenterologists will be increasingly called on to treat patients with pancreatitis and its complications. This article addresses and summarizes pancreatic fluid collections and their management, with an emphasis on endoscopic drainage.

Adult↗
PubMed1997

The diagnosis and management of fluid collections associated with pancreatitis.

Pancreatitis may be acute or chronic, mild or severe. Acute necrotizing pancreatitis remains the most serious form of acute pancreatitis and accounts for the majority of complications. Although there is an established nomenclature for pancreatitis and pancreatic fluid collections, such as pancreatic pseudocysts, it is not widely understood or recognized by physicians, including gastroenterologists. Because nonspecialists will be increasingly called upon to treat and appropriately refer patients with pancreatitis and its complications for more specialized care, it is important to understand the evolving treatment options for managing these patients. This article addresses and summarizes pancreatitis and its complications, particularly pancreatic collections.

Abscess↗
PubMed1997

Computed model of gadolinium enhanced MRI of breast disease.

OBJECTIVE: Investigation has shown that the most useful MRI finding for the detection of breast cancer is enhancement following in travenous contrast. However, many widely different imaging protocols have been used. The purpose of this study is to explicate factors that affect the signal intensity of breast lesions after intravenous gadolinium. METHODS AND MATERIALS: A computer model was developed using equations based on published data. The effect of gadolinium on breast tissues was calculated using the model with appropriate values for baseline tissue relaxation times, relaxivity of gadolinium at the given field strength and concentration of gadolinium based on published data, for the TR, TE, flip angle and field strength of several published sequences used for enhanced breast MRI. RESULTS: The computer model allows comparison of the performance of different sequences, which can be displayed graphically. These vary in their performance, largely dependent on T1 weighting. Enhancement is also affected by the baseline of the T1 of the lesion and sensitivity of the sequence to gadolinium. Malignant lesions demonstrate greater observed enhancement than predicted when assuming symmetric distribution of contrast, indicating there is greater accumulation of gadolinium, accounting for the differential enhancement between benign and malignant lesions. CONCLUSIONS: MRI sequences vary greatly in their demonstration of enhancement after intravenous gadolinium contrast. Numerical diagnostic criteria such as % signal intensity change must be interpreted with care when using a different sequence than that on which the criterion was developed. There is preferentially greater accumulation of contrast in malignant lesions, whether due to angiogenesis or altered permeability.

Algorithms↗
PubMed1997

Pancreatic fluid collections prior to intervention: evaluation with MR imaging compared with CT and US.

PURPOSE: To evaluate the ability of magnetic resonance (MR) imaging to depict solid debris within pancreatic collections prior to intervention and to help assess drainability, as well as to compare MR findings with those obtained at computed tomography (CT) and ultrasound (US). MATERIALS AND METHODS: Nineteen collections in 18 patients were evaluated with MR imaging, CT, and US prior to drainage. Prospective, blinded interpretations of imaging studies by three independent readers (each interpreted all the images obtained with only one modality) evaluated collection characteristics (debris, consistency, septation, wall thickness, and irregularity) and predicted drainability. Findings were compared with clinical diagnosis and clinical outcome of drainage. RESULTS: MR imaging and CT depicted all collections; US failed to depict two collections. In nine patients with subacute necrotic collections, solid debris was seen in eight (89%) at MR imaging, in two (22%) at CT, and in eight (89%) at US. In seven patients with pseudocysts, debris was seen in two (28%) at MR imaging and in none at CT, as well as in six (100%) of six at US. A collection was defined as "not drainable" on the basis of the depiction of solid necrotic debris more than 1 cm in diameter. With this definition, statistically significant differences between sensitivity and specificity values, respectively, were found for the prediction of actual drainability: MR imaging, 100% and 100%; CT, 25% and 100%; US, 88% and 54%. CONCLUSION: Predrainage MR imaging should be performed in patients with subacute pancreatic collections to avoid infectious complications from unrecognized necrotic debris that cannot be removed with use of standard pseudocyst drainage techniques.

Abscess↗
PubMed1997

Treatment of colonic obstruction with expandable metal stents: radiologic features.

OBJECTIVE: The purpose of this prospective study was to evaluate the efficacy of expandable metal stents for colonic decompression in patients presenting with acute malignant obstruction and to describe the associated radiographic findings. SUBJECTS AND METHODS: Using both fluoroscopic and endoscopic guidance, we placed expandable metal stents within the colons of 13 patients presenting with acute malignant obstruction. Stents were placed in four patients to permit a standard bowel cleansing before surgical resection with primary anastomosis. In the other nine patients, stents were placed for palliation of nonresectable tumors, obviating colostomy. Outcomes and complications were analyzed. The radiologic aspects of procedural planning, stent placement, assessment after placement, and detection of complications were evaluated. RESULTS: Of the four surgical candidates who were successfully resected with primary anastomosis, two received incomplete bowel cleansing because of stent migration with recurrent obstruction. Eight of the nine patients who had stents placed for palliation of nonresectable tumors had relief of acute obstruction. Complications in this group included two perforations, one that required immediate colostomy and one that was self-limited and conservatively treated. Two other patients of the eight developed early stent obstruction, requiring colostomy in one. The other patient who had a stent placed for palliation of a nonresectable tumor declined further treatment. Contrast-enhanced enema examination proved useful in assessing the suitability of lesions for stent decompression, directing the choice of stent type and the most appropriate position for the patient during the stent placement. Immediately after stent placement, plain abdominal radiographs and water-soluble contrast enema examinations helped us verify stent position and patency. CONCLUSION: These results suggest that placement of expandable metal stents in patients presenting with acute, malignant colonic obstruction is a viable alternative to colostomy and can potentially decrease morbidity and mortality. Radiologic assessment before, during, and after stent placement plays an integral role in the management of patients undergoing stent decompression of the colon.

Acute Disease↗
PubMed1996

Endoscopic therapy for organized pancreatic necrosis.

BACKGROUND & AIMS: The treatment of patients with extensive pancreatic necrosis remains controversial; a subpopulation of patients with extensive acute pancreatic necrosis develop complex, organized collections. This study examined the feasibility of endoscopic drainage in patients with extensive organized pancreatic necrosis. METHODS: Eleven patients with organized pancreatic necrosis (8 sterile and 3 infected) after severe acute necrotizing pancreatitis underwent attempted endoscopic drainage. Dynamic contrast-enhanced computerized tomography showed > or = 50% pancreatic necrosis in 10 of 11 patients in whom endoscopic drainage was performed. In 8 patients, an intrapancreatic nasobiliary lavage catheter was placed into the collection concurrently with 10F stents. RESULTS: Complete resolution was achieved nonoperatively in 9 patients. At a mean follow-up of 12 months, 1 patient developed a pseudocyst, which was successfully drained endoscopically. Complications occurred in 5, including bleeding that precluded entry into one collection. CONCLUSIONS: Endoscopic therapy may be a viable management option for a subset of patients who remain symptomatic after an episode of acute pancreatic necrosis after the necrosis has become organized and partially liquefied. Intrapancreatic lavage catheter placement is essential to the success of this procedure. Further evaluation of this technique is needed before this method can be adopted into clinical practice.

Adolescent↗
PubMed1994

Attitudes of healthcare professionals toward patient counseling on drug-nutrient interactions.

OBJECTIVE: To evaluate the attitudes of healthcare providers on drug-nutrient interaction (DNI) counseling. DESIGN: A mail survey. SETTING: Random sample of healthcare providers with interest in nutrition, practicing in Iowa or Nebraska. METHODS: A 48-item questionnaire was constructed on the basis of a review of DNI literature. The survey was sent to 100 pharmacists, 50 registered dietitians, 25 registered nurses, and 25 physicians identified from culled mailing lists of the American Society of Parenteral and Enteral Nutrition and the Iowa Nebraska Society of Parenteral and Enteral Nutrition. Assessed variables included the amount of DNI counseling provided, who is in the best position to provide DNI counseling, and what information should be included in instructional materials on DNIs for patients. Data were entered into a relational database for evaluation and comparison. RESULTS: The usable response rate was 49.5 percent (n = 99): 49 pharmacists, 29 dietitians, 18 nurses, and 3 physicians. Only 12 respondents provided DNI counseling in > 50 percent of patient interactions. Seventy-one respondents (72 percent) felt pharmacists were in the best position to discuss DNIs with patients. More than half of the respondents felt a new DNI pamphlet should be developed to replace an existing Food and Drug Administration-sponsored pamphlet. Although 70 percent felt the new pamphlet should be organized according to specific drugs, many felt the format should also include specific populations and disease states. Eighty-six percent indicated that a chart on DNIs geared toward healthcare professionals would be useful. CONCLUSIONS: Patient-oriented resources should be developed to enhance DNI counseling. Pharmacists are in a uniquely advantageous position to provide DNI counseling.

Attitude of Health Personnel↗
PubMed1994

Influencing prescribing practices and associated outcomes utilizing the drug use evaluation process.

Influencing prescribing practices and the implementation of pharmaceutical care utilizing the drug use evaluation (DUE) process at a 891-bed teaching hospital are described. The DUE program has been structured to provide for significant pharmacy involvement while maintaining medical staff responsibility as outlined by the Joint Commission on Accreditation of Healthcare Organizations. A multidisciplinary approach is used to identify problems and develop prescribing criteria and educational initiatives. Pharmacists provide drug therapy monitoring and engage in clinical interventions and documentation of outcomes on a daily basis. DUE program pharmacists help target possible interventions, assure monitoring and outcome documentation, and compile results of all initiatives for reporting purposes to the medical staff and quality assessment program. Specific performance compliance and problems are identified and incorporated into the credentialing process. Corrective measures are determined by the Pharmacy and Therapeutics (P&T) Subcommittee with subsequent actions carried out by peer physicians. The net result is a positive influence on prescribing practices that improves the appropriate and effective use of drugs and improves patient outcomes.

Anti-Bacterial Agents↗
PubMed1993

Sympathetic stimulation alters left ventricular relaxation and chamber size.

Alterations in left ventricular (LV) contractility, relaxation, and chamber dimensions induced by efferent sympathetic nerve stimulation were investigated in nine anesthetized open-chest dogs in sinus rhythm. Supramaximal stimulation of acutely decentralized left stellate ganglia augmented heart rate, LV systolic pressure, and rate of LV pressure rise (maximum +dP/dt, 1,809 +/- 191 to 6,304 +/- 725 mmHg/s) and fall (maximum -dP/dt, -2,392 +/- 230 to -4,458 +/- 482 mmHg/s). It also reduced the time constant of isovolumic relaxation, tau (36.5 +/- 4.8 to 14.9 +/- 1.1 ms). Simultaneous two-dimensional echocardiography recorded reductions in end-diastolic and end-systolic LV cross-sectional chamber areas (23 and 31%, respectively), an increase in area ejection fraction (32%), and increases in end-diastolic and end-systolic wall thicknesses (14 and 13%, respectively). End-systolic and end-diastolic wall stresses were unchanged by stellate ganglion stimulation (98 +/- 12 to 95 +/- 9 dyn x 10(3)/cm2; 6.4 +/- 2.4 to 2.4 +/- 0.3 dyn x 10(3)/cm2, respectively). Atrial pacing to similar heart rates did not alter monitored indexes of contractility. Dobutamine and isoproterenol induced changes similar to those resulting from sympathetic neuronal stimulation. These data indicate that when the efferent sympathetic nervous system increases left ventricular contractility and relaxation, concomitant reductions in systolic and diastolic dimensions of that chamber occur that are associated with increasing wall thickness such that LV wall stress changes are minimized.

Animals↗
PubMed1992

Gadolinium-enhanced MR imaging of renal masses.

Preliminary reports indicate that gadolinium-enhanced magnetic resonance (MR) imaging is highly accurate for diagnosis of renal masses. The authors demonstrate the clinical utility of MR imaging for evaluating renal masses in 26 patients for whom contrast material-enhanced computed tomography (CT) was contraindicated or inadequate for diagnosis or staging. Nine patients had complex cysts, one had a perinephric hematoma, and 16 had a solid mass (three of which were benign). All patients underwent MR imaging before and after administration of gadopentetate dimeglumine. Multiple imaging techniques and sequences were used. All tumors and no cysts enhanced with gadolinium. Even though the three benign tumors enhanced, two were differentiated from renal carcinoma on the basis of other imaging features. Unenhanced MR imaging was accurate in staging of renal carcinomas, and use of gadolinium did not improve staging accuracy. Gadolinium-enhanced MR imaging is indicated when results of CT and sonography are indeterminate for malignancy and when contrast-enhanced CT is contraindicated because of renal failure or adverse reaction to iodinated contrast material. In this latter instance, MR imaging is useful for both diagnosis and staging.

Carcinoma, Renal Cell↗
PubMed1992

Intrapulmonary teratoma: a case report and review of the literature.

Intrapulmonary teratomas are rare; only 30 cases have been reported in the world literature. These tumors are thought to originate from the third pharyngeal pouch. They occur equally in men and women and usually are diagnosed in the second to fourth decade of life. They are more often benign than malignant, although malignant lesions may have a favorable postoperative prognosis and benign lesions may exhibit high morbidity and mortality because of their size and location. These tumors present radiographically as lobulated masses that may contain calcification or peripheral collections of air. They most often occur in the upper lobes. The computed tomographic findings of intrapulmonary teratoma are less well known but have been described in two cases. An additional case is presented with a review of the literature and a tabular summary of the characteristics of this unusual entity.

Adult↗
PubMed1991

Auditory screening of infants.

Within the last 20 years, infant hearing screening has progressed from a laudable goal to a state-mandated reality in many areas of the United States. The high risk register provides a means by which history and neonatal physical examination can be used to identify the infant at risk for hearing loss. Two procedures (crib-O-gram and auditory brainstem-evoked response) have been the most common methods of screening for hearing loss in the newborn or in intensive care nurseries. Evoked cochlear emissions reportedly are identifiable in 90 to 100% of normal-hearing infants. This observation has lead to the use of evoked otoacoustic emissions as a hearing screening procedure with infants.

Acoustics↗