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Biomedical subjects

R W Powell

Publications and source records attributed to R W Powell.

At least 19 recordsLinked to original sources
PubMed1992

Acute splenic sequestration crisis in sickle cell disease: early detection and treatment.

Acute splenic sequestration crisis (ASSC) in children with various forms of sickle cell disease can result in life-threatening circulatory collapse due to the loss of circulating blood volume. Over a 6-year period we have treated 12 patients ranging in age from 5 1/2 months to 7 years presenting with acute sequestration crisis. Eleven had homozygous sickle cell disease and the other had sickle-thalassemia. One patient died of acute circulatory collapse. Eight patients underwent splenectomy after a major episode of sequestration with no serious infectious complications up to 5 years following splenectomy. Three patients with minor episodes have been followed with no recurrences. To foster early detection of this potentially lethal complication of sickle cell disease, an educational program in our Comprehensive Sickle Cell Center instructs the parents to examine the spleen and bring their child in for evaluation if the spleen enlarges. A newly developed videotape describes the common symptoms of ASSC and illustrates the technique of palpating the spleen. With early detection of sickle cell disease by neonatal screening and the educational program, the morbidity and mortality from this complication of sickle cell disease can be reduced.

Acute Disease↗
PubMed1991

A tungsten-supplemented diet delivered by transplacental and breast-feeding routes lowers intestinal xanthine oxidase activity and affords cytoprotection in ischemia-reperfusion injury to the small intestine.

Ischemia-reperfusion injury has been implicated as playing a major role in the development of necrotizing enterocolitis, a major cause of morbidity and mortality in the newborn. A tungsten-supplemented molybdenum-free diet can reduce xanthine oxidase (XO) enzyme activity in the intestine, which in turn reduces the generation of oxygen radicals after an ischemia-reperfusion insult. This study evaluated the ability of this diet to be effective by indirect means, ie, transplacental and breast-feeding routes. XO activity of the intestine was measured in three groups of CD-1 white rats: I, weanlings fed the tungsten diet or standard chow for 1 week; II, 1-day-old rat pups whose mothers were maintained on the tungsten or standard chow for 7 to 10 days prior to term; and III, rat pups at 1 and 3 weeks after birth whose lactating mothers were maintained on the tungsten or standard chow. Some animals from group III also underwent either a 30- or 60-minute episode of occlusion of the superior mesenteric artery (SMA) to evaluate the protective effects of the diet. XO activity was significantly reduced in all groups receiving the tungsten diet (P less than .0001). Blinded histopathologic studies of the entire small bowel showed significantly less villar necrosis (P less than .05) and fibrosis (P less than .0001) in the tungsten-treated group than in the controls. In the 60-minute occlusion study all tungsten-group animals survived, whereas 7 of 12 in the control group died of intestinal infarction within 24 hours (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Intraoperative evaluation of intestinal ischemia: a comparison of methods.

Methods for evaluating intestinal ischemia include standard clinical criteria, Doppler ultrasonography, and intravenous fluorescein injection. Each has disadvantages, and a combination of methods is often used. The purpose of this study was to determine whether surface oximetry could be used to assess perfusion in an animal whose intestinal diameter approximates that of infants. Reversible arterial, venous, and arteriovenous occlusion was studied in rabbit intestines. After 6 to 8 hours of occlusion, intestinal vascularity was evaluated by the four methods listed. Doppler ultrasonography and surface oximetry were found to be unreliable tools for assessing perfusion in this animal model. We conclude that standard clinical criteria and fluorescein remain the standards for intraoperative evaluation of intestinal perfusion.

Animals↗
PubMed1990

Necrotizing enterocolitis in multiple-birth infants.

Over a 5-year period, 20 infants of multiple-gestation births (16 twin, 2 triplet) developed necrotizing enterocolitis (NEC) (15 infants) or suspected NEC (5 infants). During the same period, 532 infants of multiple gestations were admitted to our neonatal intensive care unit, yielding a NEC incidence in this population of 3.8%. In two twin sets, both infants developed NEC or suspected NEC, and in three sets only the affected twin was transferred to our nursery. Five infants required surgical intervention (25%) and three infants died (overall mortality, 15%). Fifteen siblings who did not develop NEC served as a control group. Analysis showed that the 1-minute Apgar score was the most significant factor in predicting NEC (P less than .028) and need for surgical intervention (P less than .020). In this series, 82% of the infants with 1-minute Apgar less than 6 developed NEC, whereas 31% with 1-minute Apgar greater than 6 developed NEC.

Apgar Score↗
PubMed1989

Diagnostic pneumoperitoneum in the pediatric patient with a unilateral inguinal hernia.

Controversy continues among surgeons over the management of pediatric patients with unilateral groin hernias. Currently, advocated treatment modalities include repair of only the clinically apparent side, exploration of the contralateral side when the ipsilateral hernia is repaired, or performance of contrast herniography before surgery. Another technique for consideration--diagnostic intraoperative pneumoperitoneum--is a simple, quick, safe, and highly accurate means of detecting a clinically inapparent contralateral inguinal hernia during the initial surgery. This technique, the results of its use, and a review of the literature are included.

Adolescent↗
PubMed1989

Breast masses in young women.

To better define the risk of breast cancer in young patients, a retrospective review of all breast biopsies in women under age 40 years at Grady Memorial Hospital, Atlanta, from Dec 1, 1981, to Aug 15, 1987, was performed. During this time, 751 biopsies were performed on patients aged 9 to 40 years. None of the 128 patients aged 20 years or less had carcinoma. Of 150 patients aged 21 to 25 years, two had carcinoma. At age 26, there began a steady rise in the incidence of carcinoma, such that in the 36- to 40-year age group, carcinoma was present in 24.4% of the specimens. This retrospective review confirms previous reports that suggest that carcinoma of the breast is distinctly unusual in patients under age 20 and that breast masses in these young patients should be managed conservatively. As the incidence of carcinoma increases with the age of the patient, one's threshold for excisional biopsy should decrease.

Adenofibroma↗
PubMed1989

Costs vs. quality.

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Costs and Cost Analysis↗
PubMed1989

Hirschsprung's disease in adolescents. Misadventures in diagnosis and management.

Three male adolescents, ages 13, 15, and 17 years, presented with complications of their Hirschsprung's disease, including acute enterocolitis with sepsis, chronic enterocolitis with anemia and leukocytosis, and severe fecal impaction. All had experienced delay in diagnosis resulting from either physician error in diagnosis or physician misinformation concerning the surgical treatment of the disease. These three patients illustrate some of the pitfalls in the diagnosis and surgical management of patients with Hirschsprung's disease. Misinformation concerning the surgical correction of this disease still exists, and these patients emphasize the necessity of continued, updated information in the diagnosis, management, and outcome of patients with Hirschsprung's disease.

Adolescent↗
PubMed1988

The predictive validity of the Pediatric Trauma Score.

The Pediatric Trauma Score was evaluated in 450 injured children by a paramedic in the field and a physician in an E.D. There was agreement between the scores of these two individuals 93.6% of the time, correlation coefficient 0.991, r2 = 0.982. Further testing at the 0.01 level of significance indicated that a positive association existed between these two variables in the population from which our sample was drawn. Mortality for the group was 2.9%. No deaths occurred in patients whose PTS was greater than 8, which was defined as the Critical Triage Point. The sensitivity of the PTS when used for triage at the critical triage point was 95.8%. The specificity of the PTS was 98.6%. The Pediatric Trauma Score appears to be highly accurate, reliable, predictable, and easy to use for assessing the severity of injury and hence is a straightforward modality for triage of injured children.

Adolescent↗
PubMed1988

The efficacy of postsplenectomy sepsis prophylactic measures: the role of penicillin.

The well documented increased susceptibility of the asplenic host to overwhelming sepsis by encapsulated organisms has led to three popular prophylactic measures in patients: 1) pneumococcal vaccination; 2) vaccination with oral penicillin prophylaxis; or 3) vaccination with penicillin use at the first sign of infection. An animal model (weanling CD-1 rats) was utilized to evaluate these prophylactic measures. One hundred sixty rats underwent splenectomy and were divided into four treatment groups: I) sham vaccination; II) pneumococcal vaccination; III) vaccination and IM penicillin 24 hours after intraperitoneal inoculation of 10(6) Streptococcus pneumoniae type III; IV) vaccination and IM penicillin starting 3 days before IP inoculation. Six days following the bacterial challenge survival rates by group were: I) 5%; II) 25%; III) 100%; IV) 100% (p less than 0.001 by phi 2 likelihood ratio). Mantel- Cox log rank analysis of survival curves yielded significant differences between all groups except III and IV (p less than 0.001). This study in weanling rats supports the use of penicillin in the asplenic host. Daily prophyactic penicillin or penicillin started at the first sign of infection appears to be equally effective. Randomized studies in humans would determine the best regimen.

Animals↗
PubMed1978

Delro??

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Delaware↗
PubMed1978

Modified technique for radical transmediastinal forequarter amputation and chest wall resection.

Forequarter or interscapulothoracic amputation is a major surgical procedure indicated primarily in the treatment of malignant lesions involving the bony and soft tissue parieties of the upper part of the arm, shoulder, and scapula. It is also indicated in extensive trauma with irreparable damage to the shoulder area and as a palliative measure in intractable pain caused by incurable tumors of the shoulder girdle. Several operative techniques have been described: the classical Berger approach, an anterior pectoral approach, and posterior retroscapular approaches. A radical transthoracic approach has been described in cases in which the tumor had spread through the chest wall. The two main goals of these approaches have been early ligation of the subclavian vessels and immediate exploration for operability. This report details our experience with a modified technique for radical forequarter amputation and chest wall resection in which a transmediastinal approach is employed. This approach was used in two patients: One had a radiation-induced fibrosarcoma of the left axilla and adjacent chest wall following a radical mastectomy 19 years earlier, and the other patient had a recurrent rhabdomyosarcoma of the right axilla with invasion of the chest wall. This technique avoids time-consuming and individual excision of ribs and minimizes the amount of blood loss by early ligation of the internal mammary vessels. Safe and excellent exposure and division of the subclavian vessels and early exploration for mediastinal and intrathoracic involvement are made possible. Details of the procedure with illustrations are described.

Amputation, Surgical↗
PubMed1977

Paget disease of the male breast.

Twenty-two fully documented cases of Paget disease of the male breast are reviewed, and an additional patient is reported. The most common initial symptom was ulceration and excoriation, while a breast mass was palpable in the majority of patients. Nipple changes were surprisingly rare, in contrast to the female. The prognosis of the disease in the male appears to be worse than in the female, with the Paget carcinoma carrying a worse prognosis than the "ordinary" male breast cancer. The subareolar location and the meager volume of tissue interposed between the tumor and chest wall may be an important factor in this regard. Nipple changes or symptoms (ulceration, discharge, enlargement) are mroe apt to be due to cancer in the male than in the female. Therefore, prompt diagnosis is mandatory.

Adult↗
PubMed1976

Peritoneal lavage in children with blunt abdominal trauma.

Quantitative peritoneal lavage was performed in 52 children with blunt abdominal trauma to determine the presence of intraabdominal injuries. A strongly positive lavage was 100% accurate in diagnosing an intraabdominal injury requiring operation. A negative lavage demonstrated absence of a significant intraperitoneal injury with 100% accuracy. A weakly positive lavage was not diagnostic and required additional evaluation including intravenous pyelography echography, and arteriography. Diagnosis and treatment was prompt, and in 20 of 21 cases, operation was performed within 4 hr. Peritoneal lavage was found to be safe and much more accurate than physical examination in diagnosing significant intraabdominal injury.

Abdominal Injuries↗