Biomedical subjects

T R Weber

Publications and source records attributed to T R Weber.

At least 55 records · Page 3Linked to original sources

PubMed1993

Nitrogen balance in patients treated with extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a commonly used technique in the management of newborn respiratory failure. However, few studies have addressed the optimal nutritional support of these critically ill neonates. Eleven newborns undergoing ECMO for respiratory failure were studied at various levels of intravenous caloric and nitrogen intake, using nitrogen balance techniques, to assess optimal nutritional support necessary to achieve positive nitrogen balance. Nonprotein nitrogen calories > 60 kcal/kg/d, and nitrogen > 240 mg/kg/d were necessary to achieve positive nitrogen balance, while maximum positive balance was seen with nitrogen intake > 400 mg/kg/d. These data suggest that newborns treated with ECMO can achieve positive nitrogen balance with modest amounts of caloric and nitrogen intake.

Energy Intake↗

PubMed1993

A clinical-pathological study of nonsurvivors of newborn ECMO.

Extracorporeal membrane oxygenation (ECMO) is an important means of supporting newborns with respiratory failure. While short- and long-term follow-up of ECMO survivors has been thoroughly addressed, there is no systematic study of nonsurvivors. Nineteen nonsurvivors of newborn ECMO with autopsy results are divided into two groups: group 1: 12 patients who had intracranial lesions as the primary cause of death (hemorrhage 8, encephalomalacia 2, infarct 2); and group 2: 7 patients with nonintracranial primary causes of death. Patients in group 1 were significantly more acidotic, hypotensive, and smaller in age and birth weight pre-ECMO. Among group 2 patients, two with diaphragmatic hernia died of primary pulmonary disease (diffuse alveolar damage, pulmonary hypoplasia and necrosis, bronchopneumonia). One of 2 patients with persistent fetal circulation (PFC) was treated with massive doses of tolazoline and suffered fatal gastrointestinal hemorrhage and ischemic necrosis of heart, spleen, testes, and adrenals. The other PFC patient had severe pulmonary interstitial fibrosis. Two patients with meconium aspiration and a patient with streptococcal sepsis had diffuse pulmonary damage and multiple organ failure (renal medullary necrosis, and infarcts of adrenal, spleen, liver). In this series, intracranial pathology was the most common cause of death in ECMO patients, related to gestational age, acidosis, hypoxia, and size, but probably unrelated to carotid ligation.

Acidosis, Lactic↗

PubMed1993

Congenital duodenal obstruction: a 32-year review.

Although survival in infants with congenital intestinal obstruction has improved, duodenal obstruction continues to present unique challenges. One hundred thirty-eight newborns and infants (aged 0 to 30 days) were treated for congenital duodenal obstruction. Sixty-five were boys and 73 were girls. Sixty-one (45%) were premature. Forty-six had an intrinsic defect (atresia, web, stenosis, or duplication), 64 had an extrinsic defect (annular pancreas or malrotation with congenital bands), while 28 had various combinations of these. Presenting signs included vomiting (90%, bilious in 66%), abdominal distention (25%), dehydration (24%), and weight loss (17%). Although plain film abdominal x-ray was diagnostic in 58%, upper and/or lower gastrointestinal contrast studies were obtained in 71% of infants to confirm diagnosis. Thirty-eight percent of patients had associated anomalies, including Down's syndrome (11%), cardiac defects, other atresia, other trisomy syndrome, imperforate anus, and central nervous system anomalies. Fourteen patients (10%) had 3 or more other anomalies, many of which required additional surgical therapy. The operative repair of the various defects included Ladd's procedure for malrotation (31%), duodenoduodenostomy (14%), duodenojejunostomy (22%), gastrojejunostomy or gastroduodenostomy (4%), excision of the web and duodenoplasty (3%), or combination of the above (22%). Gastrostomy was placed in 61%. One hundred twenty-eight patients survived (93%). The causes of death were combinations of sepsis, pneumonia, brain hemorrhage, short bowel, and cardiac anomaly. Eight of 10 (80%) who died had other serious anomalies. Twenty patients (14%) required reoperation 5 days to 4 years postoperatively for obstructing lesions (5), wound dehiscence (3), anastomotic leak or dysfunction (6), other atresias (2), choledochal cyst (1), pyloric stenosis (1), and gastroesophageal reflux (2).(ABSTRACT TRUNCATED AT 250 WORDS)

Duodenal Obstruction↗

PubMed1993

Growth-related gene expression in early cholestatic liver injury.

BACKGROUND: Extrahepatic biliary obstruction initiates cholestasis, bile duct proliferation, periportal fibrosis, and, eventually, lethal biliary cirrhosis. Little is known about the genetic regulation of the cellular proliferation and differentiation that begins with the onset of bile duct obstruction. To focus this and future gene expression studies, we sought to determine the time frame for growth-related gene expression and questioned whether the in vivo expression of the protooncogenes H-ras and c-myc was altered after bile duct obstruction. METHODS: Female Fisher rats underwent ligation and division of the common bile duct or sham laparotomy. RESULTS: After obstruction, serum bilirubin and gamma-glutamyl transpeptidase rose to 24% and 30%, respectively, of maximum levels by 10 days after ligation. Morphologic evidence of proliferation of bile duct epithelial cells was first evident after 3 days. After hybridization to c-DNA probes, densitometry for H-ras and beta-actin revealed an immediate and parallel increase in steady-state levels of expression after 24 hours of cholestasis. Levels of c-myc messenger RNA were elevated during the first 3 days of cholestasis; however, at 7 and 10 days c-myc expression was depressed 16% and 60%, respectively. CONCLUSIONS: These profiles of expression show an oncogene response induced by early cholestasis. These data showed that elevations in H-ras and c-myc steady-state expression accompany the proliferative response of bile duct epithelial cells. Decreased levels of c-myc after initial elevation infer that ductal proliferation may continue independently of its steady-state expression, a response usually seen in vitro rather than in in vivo proliferation.

Actins↗

PubMed1993

Congenital hemangiopericytoma: an unusual vascular neoplasm of infancy.

BACKGROUND: Hemangiopericytoma is an uncommon tumor of infants, which originates from the vascular pericytes. Although generally considered to benign, metastases can occur. METHODS: Five cases of congenital hemangiopericytoma were seen in infants; all were found in females. The mean age at diagnosis was 7 weeks (range, birth to 10 weeks). The lesions were located in the neck, the parotid, the axilla, and the retroperitoneum. One neck lesion was detected prenatally by ultrasonography. Each lesion was resected. The diagnosis of congenital hemangiopericytoma was established only after histologic examination. RESULTS: No evidence of recurrence has been found in four of the children. However, intrathoracic and intracranial metastases developed in one child with a neck lesion 28 months after the original resection, and the child was treated with chemotherapy, but she died of progressive disease. CONCLUSIONS: We advocate the consideration of congenital hemangiopericytoma in the newborn infant with a vascular mass. Because congenital hemangiopericytoma is unresponsive to steroid therapy, unlike other vascular malformations, resection is the treatment of choice. Long-term postoperative follow-up is essential for the early detection of metastases.

Axilla↗

PubMed1993

Battered children with duodenal avulsion and transection.

Two cases of severe duodenal injury following child abuse are presented. One avulsion injury required pyloric exclusion. Both 2-year-old children survived without anastomotic complications. Survival after these injuries rests on the ability to apply multiple techniques for duodenal reconstruction, as well as the recognition of individual cases of abuse-associated malnutrition. A high index of suspicion following abuse-associated blunt abdominal trauma will prevent diagnostic delay in children with retroperitoneal duodenal injuries.

Child Abuse↗

PubMed1992

The risk of abdominal operations in children with ventriculoperitoneal shunts.

Ventriculoperitoneal (VP) shunts are the operations of choice for patients with hydrocephalus in most pediatric hospitals. Children with VP shunts frequently undergo abdominal operations unrelated to their shunts, which might lead to shunt infections or to malfunctions related to adhesions. Although prophylactic antibiotics are usually used in this setting, there are few data to support their use, or to assess other risks to the shunt from the abdominal procedures. Consequently, we reviewed the records of 37 children with VP shunts who underwent a total of 44 abdominal operations. In 8 cases, the genitourinary (GU) tract was opened (ureteral reimplantation, bladder augmentation, nephrectomy), whereas in 18 patients the gastrointestinal (GI) tract was opened (appendectomy, gastrostomy, small/large bowel resection). In 18 operations neither GI nor GU tract was opened (lysis of adhesions, herniorrhaphy, orchiopexy). Antibiotic coverage was highly variable: 9 received no antibiotics, 9 received antibiotics only postoperatively, 4 were given antibiotics only preoperatively, and in 22 cases antibiotics were given both preoperatively and postoperatively. One shunt that was involved in a periappendiceal abscess was exteriorized and later successfully replaced. In the remaining cases, no episodes of shunt infection or malfunction occurred in 1 to 10 years of follow-up. Likewise, no abdominal cerebrospinal fluid pseudocysts formed as a result of abdominal adhesions. These data demonstrate that children with VP shunts can safely undergo abdominal operations, even when the GI or GU systems are opened, with minimal risk of shunt infection or malfunction. Rigid protocols of prophylactic antibiotics cannot be supported by this series.

Abdomen↗

PubMed1992

Prolonged extracorporeal support for nonneonatal respiratory failure.

Extracorporeal membrane oxygenation (ECMO) is effective for newborns with pulmonary failure unresponsive to conventional therapy. However, ECMO for the older child and adult has been controversial and not widely utilized. Over 4 years, 24 patients (aged 4 months to 16 years; 11 boys, 13 girls) underwent venoarterial ECMO (duration, 7 to 19 days) for respiratory failure. The diagnoses were: viral pneumonia (7), hydrocarbon aspiration (6), sepsis with adult respiratory distress syndrome (ARDS) (2), bacterial pneumonitis (2), tracheal stenosis (1), bilateral pulmonary contusion (1), diaphragmatic hernia with ARDS (1), ketoacidosis with ARDS (1), pulmonary artery injection of hydrocarbon (1), drowning (1), and epiglottis with barotrauma (1). Pre-ECMO blood gas ranges (and means) were PO2 18 to 65 (46), and PCO2 47 to 112 (65). Nineteen patients received dopamine, dobutamine, or other inotrope for associated cardiac and/or renal failure. Cannulation for ECMO was through neck or groin vessels in 17, and sternotomy in 7. ECMO flow rates were 150 to 250 mL/kg/min, to maintain PO2 greater than 100 and PCO2 less than 40. Nine patients (41%) survived ECMO, with eight long-term survivors, (4 hydrocarbon aspiration or injection, 1 pulmonary contusion, 1 viral pneumonia, 1 ARDS, 1 barotrauma), three of whom have mild neurological deficit. All patients with sternotomy, and 8 of 15 with neck and/or groin cannulation, required 1 to 5 explorations for hemorrhage while on ECMO. All survivors had primarily pulmonary failure; patients with combinations of pulmonary, cardiac, and renal failure did not survive. ECMO can be life-saving in the child with isolated pulmonary failure, but its efficacy in patients with multiorgan failure is uncertain.

Adolescent↗

PubMed1992

Extracorporeal membrane oxygenation in children after cardiac surgery.

BACKGROUND: From August 1982 to May 1991, 65 children (32 boys), 1 day to 14 years old, received extracorporeal membrane oxygenation (ECMO) 0-50 hours after cardiac surgery. Forty-four (67.7%) were weaned, with 23 (35.4%) survivors. METHODS AND RESULTS: Analysis of 29 pre-ECMO factors including diagnosis, age, sex, blood gas data, systemic pressures, atrial pressures, ventricular function, and renal function was performed. Preoperative systemic ventricular shortening fraction was statistically less in survivors. The need for dialysis and length of support were predictors of survival once ECMO was initiated. There were five late deaths 6 days to 5 years after discharge; none were related to ECMO. The remaining 18 patients have been followed for a mean of 37.5 months (range, 1-85 months). Seventeen are New York Heart Association functional class I, with one patient still hospitalized. CONCLUSIONS: ECMO allows for myocardial recovery in the majority of patients with refractory postcardiotomy failure and permits some patients to survive who would not have otherwise.

Adolescent↗

PubMed1992

Current concepts in neuroblastoma.

With the fund of knowledge presented here, clinical practice can begin to apply what basic science has discovered. New approaches to immunotherapy and genetic engineering will supplant the current surgical tools for our fight against this tumor.

Humans↗

PubMed1991

Short-bowel syndrome in children. Quality of life in an era of improved survival.

A number of disorders in childhood can result in short-bowel syndrome (small bowel length, less than 100 cm). Improved care has increased survival in patients with short-bowel syndrome, but the quality-of-life factors associated with such improved survival have not been examined, to our knowledge. Sixteen consecutive pediatric patients with short-bowel syndrome (bowel length range, 22 to 98 cm) were followed up for 2 to 10 years. The original diagnoses were as follows: necrotizing enterocolitis (n = 6), multiple intestinal atresias (n = 4), extensive aganglionosis (n = 2), meconium peritonitis (n = 2), and midgut volvulus (n = 2). The range of initial hospitalization was from 62 to 395 days, and 13 of 16 patients have required readmission (two to 14 times). All patients required multiple operations (range, two to 14 operations), including combinations of venous access, adhesiolysis, tapering enteroplasty, reversed intestinal segments, and pull-through procedure. Nine of 16 patients received home total parenteral nutrition, and 12 of 16 patients required home elemental diets, usually via pump feedings. Fifteen patients (94%) survived. Two survivors are deaf, and one of these has mild developmental delay. Seven survivors (age range, 6 to 10 years) attend a regular school, four while receiving total parenteral nutrition or an elemental diet. Ten of 15 survivors are off all nutritional support (including the child with a 22-cm small bowel), with four others weaning. The presence or absence of an ileocecal valve did not affect outcome. Modern nutritional support methods provide excellent survival and quality of life for children with short-bowel syndrome.

Child↗

PubMed1991

Congenital diaphragmatic hernia beyond infancy.

Congenital diaphragmatic hernia (CDH) is a common cause of severe respiratory distress in the newborn. However, the presentation of CDH in older children and adults is rare, and, therefore, little is known concerning its symptoms, operative management, and postoperative complications. Thirteen patients (age range: 2 months to 26 years; 5 males, 8 females) presented with CDH. Four patients had right-sided hernias, eight left-sided hernias, and one bilateral hernias. Symptoms included chronic respiratory tract infections in 6 patients, vomiting in 5, weight loss in 1, severe failure to thrive in 2, and severe respiratory distress in 3; one patient was asymptomatic. Physical signs included the absence of breathing sounds or bowel sounds in the chest in eight patients, hyperresonance in one, and cachexia in two. The diagnosis was confirmed in each patient by chest roentgenogram or gastrointestinal contrast radiograph. All patients underwent immediate repair. After reduction of the viscera, 12 of 13 patients underwent primary diaphragm repair, whereas one patient required a prosthetic diaphragm patch. Twelve of 13 patients (92%) survived. Postoperatively, 7 of the 12 survivors (58%) developed severe gastric atony, and four required further operative therapy. In contrast to newborns, CDH in the older child and adult is frequently seen on the right side, rarely presents with severe respiratory distress, and is occasionally asymptomatic. Postoperative gastric atony is a major cause of morbidity, making transabdominal repair with simultaneous pyloroplasty and/or feeding jejunostomy the preferred operative approach.

Adolescent↗

PubMed1991

Congenital tracheal stenosis with unilateral pulmonary agenesis.

Cogenital tracheal stenosis with unilateral pulmonary agenesis is a rate and frequent fetal combination. In an 8-year period, 5 infants (ages 2 to 6 months) with these anomalies were treated. The presenting signs and symptoms consisted of wheezing, stridor, and tachypnea and included frank respiratory failure requiring emergency therapy in several patients. The operative repair consisted of segmental resection and anastomosis in one patient, and rib-cartilage tracheoplasty in the other four. Two infants died, one of cerebral hypoxia, and the other of aortotracheal fistula. Long-term follow-up in the three survivors is satisfactory.

Abnormalities, Multiple↗

PubMed1991

Cholestasis without cirrhosis alters regulatory liver gene expression and inhibits hepatic regeneration.

Partial hepatectomy (PH) initiates cellular signals for regeneration. Sequential expression of nuclear and cytosolic protooncogenes accompanies the restoration of normal liver function and architecture. Although cirrhosis is known to inhibit liver regeneration, the effects of noncirrhotic cholestasis on hepatocellular proliferation, differentiation, and regulatory gene expression are unknown. To examine this, 25 male Fisher rats underwent common bile duct ligation and division. A 47% +/- 5% PH was performed 10 days after common bile duct ligation and division when histologic analysis revealed cholestasis without cirrhosis. Despite early elevations of total hepatic DNA and RNA values, cholestatic livers demonstrated a significant threefold suppression of expected hepatocyte mitotic indexes 48 and 72 hours after PH, compared with livers after PH alone. Weight restoration in cholestatic livers was 11% +/- 5.2% compared with 40% +/- 4.3% in control livers (+/- SEM; p less than 0.001) 5 days after PH. Analysis of regenerating liver messenger RNA with complementary DNA probes revealed an abnormal, sustained elevation of K-ras expression in cholestatic livers through all time points. Cholestasis blunted but did not obliterate normal sequential elevations in H-ras found in control livers. The expression of c-myc was inhibited threefold with cholestasis 72 hours after PH. These results are the first indication that cholestasis alone inhibits hepatocyte proliferation and the expression of c-myc that normally precedes the first wave of mitosis. This implies that cholestasis without cirrhosis may alter programmed liver gene expression, inhibiting normal hepatic regeneration.

Animals↗

PubMed1991

Complement activation during prolonged extracorporeal membrane oxygenation.

Short-term cardiopulmonary bypass activates the complement system, possibly resulting in pulmonary dysfunction from granulocyte aggregation and pulmonary endothelial damage. These effects may be inhibited by steroids. Prolonged extracorporeal membrane oxygenation (ECMO) is used for newborn respiratory failure, but the effects of ECMO on complement activation are unknown. Twenty-one newborn infants with respiratory failure treated with ECMO were randomly assigned to group I (control, no steroids) or group II (30 mg/kg intravenous methylprednisolone before ECMO). Depletion assays of C3 and C5 were performed in each group at intervals before and during ECMO (declining values indicate complement activation). The groups were compared for complement levels, survival, time on ECMO and on the ventilator, and total hospitalization time. Steroids significantly shortened the time on ECMO and time on the ventilator after ECMO but did not affect survival or total hospitalization time. Steroids also enhanced activation of C3 and C5. Complement activation occurs during ECMO. Steroid administration paradoxically causes earlier complement activation but shortens ECMO and ventilator times. Complement activation during ECMO is of questionable significance. The benefits of steroids during ECMO may be mediated through other mechanisms.

Birth Weight↗

PubMed1991

Acquired tracheal stenosis in infants and children.

Acquired tracheal stenosis in childhood is frequently difficult to manage because of poor healing, infection, and scarring. In a 10-year period, 62 patients (4 weeks to 14 years of age) were treated for acquired tracheal stenosis. The causes of stenosis were endotracheal intubation (44 patients), caustic aspiration (6 patients), recurrent infection (5 patients), bronchoscopic perforation (4 patients), and gastric aspiration (3 patients). The subglottic or upper trachea was involved in 47 patients, mid portion in 8, and distal or carinal area in 7. Fifty children underwent tracheostomy as part of the therapy, and 12 were managed without tracheostomy. Therapy was individualized, frequently sequentially, utilizing rigid or balloon dilatation (20 patients), bronchoscopic electrocoagulation resection (44 patients), steroid injection (48 patients), T tube stent (8 patients), resection with anastomosis (12 patients), cricoid split (3 patients), and rib cartilage graft (12 patients). Most patients required several techniques and repeated procedures to eventually achieve decannulation. Seven patients (11%) died of unrelated causes. Forty-four of 55 surviving patients (80%) are without tracheostomy, although 14 have required continued endotracheal treatment after tracheostomy removal (dilatation, endotracheal resection). This series demonstrates that acquired tracheal stenosis in childhood is a common, difficult problem, but manageable with the use of a variety of techniques. Resection and grafting procedures should be reserved for cases in which less complex modalities fail.

Adolescent↗

PubMed1990

Extracorporeal membrane oxygenation for hydrocarbon aspiration.

Extracorporeal membrane oxygenation is a pulmonary bypass procedure that has been employed in adults to provide temporary treatment for reversible acute pulmonary and cardiac insufficiency. The technology of membrane oxygenation has been used since 1977 in neonates with predictably fatal pulmonary failure due to respiratory distress syndrome, persistent fetal circulation or persistent pulmonary hypertension of the newborn, meconium aspiration syndrome, and congenital diaphragmatic hernia. The use of extracorporeal membrane oxygenation in older children with other pulmonary disorders has been limited. We report two cases of hydrocarbon aspiration involving petroleum-based products, both successfully treated with extracorporeal membrane oxygenation. A 15-month-old male infant who aspirated baby oil (light mineral oil) is particularly unusual owing to the generally expected low risk of aspiration with a hydrocarbon of such viscosity (greater than 60 Saybolt Universal Seconds). The second patient is a 16-month-old male infant who aspirated furniture polish (mineral seal oil). In both children severe intractable hypoxemia developed despite intensive ventilatory support, and they became candidates for alternative therapy. Extracorporeal membrane oxygenation provides a potentially life-saving option when a patient fails to respond to conventional therapy for hydrocarbon aspiration.

Extracorporeal Membrane Oxygenation↗

PubMed1990

Complex hemangiomas of infants and children. Individualized management in 22 cases.

Large hemangiomas in infants and children are rare but can be life-threatening if they involve vital structures or produce thrombocytopenia or congestive heart failure. During a 6-year period, 22 infants and children, aged newborn to 7 years, were treated for complex, symptomatic hemangiomas. The lesions were located in the liver in seven, face or parotid gland in five, neck in four, extremity in two, and mediastinum, chest wall-spinal cord, trachea, and retroperitoneum in one patient each. The diagnosis was suggested by physical examination in all patients and was confirmed by radiologic examination in most patients. The treatment was individualized, usually progressed from less to more invasive, and included observation, prednisone therapy, arterial ligation, and resection. All children were eventually cured, with minimal morbidity. Children with life-threatening hemangiomas can be successfully managed with the use of a variety of techniques.

Angiography↗