Search PubMed⌕ Search

Biomedical subjects

W W Neblett

Publications and source records attributed to W W Neblett.

At least 37 records · Page 2Linked to original sources

Continuous regional anaesthesia in infants.

Physiological immaturity of the respiratory musculature and central respiratory control centres leads to an increased risk of apnoea and respiratory complications following general anaesthesia in neonates. Regional anaesthetic techniques may obviate the need for general anaesthesia and lessen the risks of perioperative morbidity. Although these techniques have been described in infants, previous reports have dealt with single-shot techniques for brief surgical procedures (< 60 min). Experience with prolonged operative cases using regional anaesthesia via indwelling catheters in infants is limited. We present our experience with four infants in whom either caudal epidural or spinal anaesthesia was administered via indwelling catheters for operative procedures that lasted 90 to 180 min. We believe this technique is an alternative to general anaesthesia in these patients.

Anesthesia, Caudal↗

Pulmonary sequestration: diagnosis with color Doppler sonography and a new theory of associated hydrothorax.

The diagnosis of pulmonary sequestration has traditionally relied on angiographic demonstration of a systemic artery to the sequestered lung tissue. Rarely, extralobar sequestration can be associated with tension hydrothorax, which in the past has invariably led to fetal hydrops and death. The authors report the cases of three infants who had initially undergone color and spectral Doppler analysis; in two of them, extralobar sequestrations were associated with congenital hydrothorax. All three patients underwent surgical resection and histopathologic evaluation of their sequestrations. On the basis of the findings, the authors believe that torsion of the sequestration occludes the efferent venous and lymphatic channels, initiating the accumulation of pleural fluid and subsequent hydrops through systemic venous obstruction. Color Doppler made possible the identification of minute feeding vessels, obviating further diagnostic studies.

Bronchopulmonary Sequestration↗

Parapneumonic empyema in children: decortication hastens recovery in patients with severe pleural infections.

The medical records of 61 children 0 to 18 years of age treated for empyema complicating pneumonia from 1977 to 1989 were reviewed with attention to clinical presentation, bacteriology, treatment and outcome. Streptococcus pneumoniae was the most common infecting organism, followed by Staphylococcus aureus, other streptococcal species, anaerobes, Haemophilus influenzae type b, Pseudomonas aeruginosa, and Eikenella corrodens. No organisms were recovered in 39% of patients. Twelve patients were treated successfully with antibiotics and thoracentesis alone, 23 patients underwent close tube thoracostomy and 26 required decortication. A thickened pleural "peel," scoliosis and opacification of a hemithorax on chest radiograph, as well as low pleural pH and glucose concentration, were associated with a poor response to medical management. A scoring system was developed to define the severity of pleural disease. In patients with severe pleural infections, decortication allowed more rapid defervescence (2.2 vs. 6.5 days) and earlier hospital discharge (4.4 vs. 12.4 days) than did closed tube thoracostomy (P less than 0.001).

Adolescent↗

Alcohol and the adolescent trauma population.

Trauma is the leading killer of children and adolescents between 1 and 21 years of age. Alcohol-impaired driving represents the single greatest cause of mortality and morbidity of children over the age of 6. We retrospectively reviewed 878 consecutive adolescent (age range, 16 to 20 years) trauma admissions for blood alcohol concentration (BAC). Four hundred sixty-seven patients had BAC drawn, 258 were BAC-negative (group I), 209 (48%) were BAC-positive (group II). The adolescent drinkers were then compared with a group of 748 adult drinkers (group III). Groups I and II differ in sex, age, time of day of the accident, Injury Severity Score, Glasgow Coma Score, and Revised Trauma Score, whereas group II and III differ by type of accident, type of injury, socioeconomic factors (bad debt), time of day of the injury, and BAC. There were no significant differences in TRISS predicted survival, actual survival, nor mean length of stay. We conclude that (1) alcohol is a significant contributor to injury during adolescence, and (2) adolescent drinkers differ from adult drinkers in their habits, demographics, and socioeconomic status. These socioeconomic differences have implications for the access to and cost-effectiveness of interventions.

Accidents, Traffic↗

Burn injury alters intestinal glutamine transport.

Several studies have established that intestinal glutamine (GLN) metabolism is altered during catabolic states. It remains unclear whether these alterations are due to a defect in metabolism or in transport of the amino acid. The present study examines the kinetics of GLN transport across basolateral membrane vesicles (BLMV) of enterocytes obtained from control rats and rats subjected to 20% full-thickness scald burn, 48 hr previously. BLMV were prepared from freshly isolated enterocytes using differential centrifugation with separation on a Percoll density gradient. BLMV were enriched (10- to 12-fold) with Na+-K+-ATPase while markers for brush border membranes were impoverished. Previous studies from our laboratory indicated that, in this preparation, GLN transport is into an osmotically sensitive space, dependent on GLN concentration, linear up to 30 sec, and both temperature and Na+ dependent. Our results indicate that in thermal injury, initial rates of GLN uptake were depressed (y = 3.67 + 0.435X for burned rats vs y = 18.7 + 0.907X for controls, P less than 0.01). Kinetic analysis of GLN uptake showed a marked decrease in transport Vmax (81.8 +/- 15 nmole/mg protein/15 sec for burned rats vs 185 +/- 17 nmole/mg protein/15 sec for controls, P less than 0.001). Transport Km also decreased from 0.25 +/- 0.004 mM for controls to 0.08 +/- 0.03 mM glutamine for burned rats (P less than 0.001). Kinetic studies performed at GLN levels greater than 0.6 mM showed that GLN uptake proceeded by a nonsaturable process in both the control and burned rats. No significant alteration in this nonsaturable component was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Postpneumonic empyema in childhood: selecting appropriate therapy.

In order to identify appropriate treatment options for postpneumonic empyema, we reviewed the medical records and, when possible, obtained long-term follow-up chest radiographs and pulmonary function tests on children treated for empyema during the past 11 years. Fifty-one patients were treated in various ways, with antibiotics alone (N = 10), or in combination with tube thoracostomy (N = 23) or decortication (N = 18). Despite administration of appropriate antibiotics and establishment of pleural drainage, many children required prolonged hospitalization and eventual decortication. Based on this review, a scoring system was developed allowing early classification by severity of pleural disease. Factors found to be predictors of severe pleural disease include (1) low pleural fluid pH or (2) glucose; (3) presence of moderate or severe scoliosis or (4) pleural peel or parenchymal entrapment by chest radiography; and (5) infection due to anaerobes, gram-negative organisms, or mycoplasma. Complete opacification of a hemithorax on chest radiography and a pleural peel to thoracic ratio greater than 40% were also associated with severe pleural disease. In patients with mild disease (N = 7), response to antibiotics alone, rapid resolution of fever, and shorter hospital stays were observed. In patients with more severe infections (moderate = 22, severe = 22), decortication accomplished earlier defervescence, radiographic improvement, and hospital discharge than simple tube thoracostomy. No deaths or morbidity were associated with decortication, which could often be accomplished through a minithoracotomy. Follow-up chest radiographs and pulmonary fuction tests showed a prompt return to normal after decortication. This experience indicates utility of a pleural disease severity scoring system in selection of treatment options for children with postpneumonic empyema.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Acute abdominal conditions in children and adolescents.

Evaluation and management of the acute abdomen in childhood require a thorough familiarity with the numerous disorders that may cause abdominal emergencies. Many of these entities are rarely seen in adults or have clinical features that are very different from those observed in adults. Diagnosis is often confounded by difficulties in obtaining an accurate history and physical examination. In infants and young children, complications of various congenital abnormalities are more common causes of abdominal pain, whereas acquired disorders are observed more frequently in older children and adolescents.

Abdomen, Acute↗

Experience with adrenocortical neoplasms in childhood.

The experience with adrenocortical neoplasms in childhood is reviewed. During three decades, ten children with adrenocortical neoplasms were seen at the authors' institution. The literature was reviewed, and 209 patients 16.5 years or younger were found. All ten patients at Vanderbilt University Hospital (VUH) presented with endocrine manifestations of the tumor. Three patients had Cushing's, two patients had virilization, and five patients had features of both. In the literature, virilization, alone or with Cushing's, was the most common mode of presentation. Feminizing tumors were uncommon and nonfunctional tumors rare. The majority of patients were female. Features associated with malignancy included 17-KS levels greater than 40 mg/24 hr, diameter greater than 6 cm, weight greater than 500 g, and histologic evidence of diffuse growth pattern, vascular invasion, and tumor cell necrosis. Although uncommon, adrenocortical neoplasms should be suspected in children with Cushing's, virilization, feminization, or a combination of these. There has been an increased incidence reported in patients with hemihypertrophy, Beckwith-Wiedemann syndrome, hemangiomas, and nevi. Following endocrinologic evaluation, imaging studies should be performed. CT scan appears to be the most useful diagnostic tool. A posterior operative approach is recommended for suspected adenomas. An anterior thoracoabdominal approach is favored for suspected malignancies with uncompromised en bloc resection. There is no evidence that adjuvant therapy provides any additional benefit.

17-Hydroxycorticosteroids↗

Noncirrhotic portal fibrosis after Wilms' tumor therapy.

A 9-yr-old girl developed massive hemorrhage from esophageal varices 2 yr after combined modality therapy for Wilms' tumor. Evaluation showed a patent extrahepatic portal venous system and an elevated splenic pulp pressure. In contrast to previous reports of hepatopathy after irradiation injury, histologic sections of the liver did not demonstrate occlusion of the central veins, but rather a diffuse obliteration of intrahepatic portal venous radicles. This pattern of noncirrhotic portal fibrosis has not been described following antitumor therapy.

Child↗

Spectrum of biliary disease in childhood.

Obstructive biliary disease in childhood is not common, but should be considered in the differential diagnosis of a child with jaundice, abdominal pain, or an abdominal mass. We have reviewed the experience at Vanderbilt Children's Hospital from 1970 to 1985, during which 87 children 18 years of age or younger with biliary tract disease were seen. Twelve patients (14%) had congenital disorders including choledochal stenosis, Caroli's disease, choledochal cyst, teratoma of the common hepatic duct and common bile duct, congenital septate biliary tree, and isolated atresia of the distal common bile duct. Thirty patients had neonatal cholestatic syndromes, and 37 had calculous disease of the gallbladder or extrahepatic bile ducts. Three patients had obstruction of the common bile duct caused by fibrosing pancreatitis. Two had sclerosing cholangitis. Obstruction of the common bile duct was caused by metastatic neoplasm in three patients. We discuss principles of diagnosis and management.

Adolescent↗

Management of aortic thrombosis secondary to umbilical artery catheters in neonates.

During the past ten years, we have surgically managed seven neonates who developed total occlusion of the distal aorta due to umbilical artery catheters. All patients experienced symptoms of congestive heart failure. Five patients presented with severe hypertension, and all of these had aortorenal involvement: three infants had aortorenal thrombosis and two infants had infrarenal aortoiliac thrombosis with suprarenal extension of thrombus. Two infants had aortoiliac thrombosis with clot confined to the infrarenal aorta. Aortic thrombosis imposes an additional severe hemodynamic insult in these already seriously ill infants. Survival in this group of patients depends upon prompt recognition of this problem, effective surgical correction, and careful perioperative management. Our experience suggests that this diagnosis should be entertained in the infant presenting suddenly with congestive heart failure, hypertension, or lower limb ischemia after umbilical artery catheterization. The diagnosis is preferably confirmed by real-time ultrasound and/or radionuclide flow scan, although aortography may sometimes be necessary. Surgical management includes early transabdominal aortotomy with thrombectomy. Prompt thrombectomy resulted in the survival of six patients. One infant died in acute renal failure. Renal function and leg perfusion is satisfactory in the remaining patients, although one child required later operative correction of renovascular hypertension. Two additional patients needed prolonged postoperative antihypertensive therapy for 14 to 34 months before this problem resolved. Long-term follow-up is necessary for managing renovascular hypertension and monitoring lower extremity perfusion.

Aortic Diseases↗

Longitudinal pancreaticojejunostomy in chronic relapsing pancreatitis with onset in childhood.

Despite the rarity of chronic relapsing pancreatitis in children, in the last 15 years at Vanderbilt University Medical Center and its Children's Hospital we have used longitudinal pancreaticojejunostomy in treatment of eight patients whose symptoms began in childhood. Duration of symptoms ranged from 2 to 36 years. Seven of the eight patients had hereditary pancreatitis. Recurrent epigastric pain was characteristic and serum amylase was elevated in all patients on admission or shortly thereafter. Demonstration of an obstructed dilated pancreatic duct in all and stones in seven of eight patients by operative pancreatography in three early patients and by endoscopic retrograde cholangiopancreatography (ERCP) in five others established the therapeutic problem and facilitated treatment by removal of stones and longitudinal pancreaticojejunostomy. Results were uniformly excellent, both in the early postoperative period and in long-range follow-ups. Early diagnosis and early surgical drainage of the obstructed pancreatic duct by longitudinal pancreaticojejunostomy are desirable objectives in chronic relapsing pancreatitis with onset in childhood.

Adolescent↗

Recent experience with esophageal atresia.

A nine-year experience with esophageal atresia of all types is described with current diagnostic and therapeutic approaches and long-term results. During this time, 53 neonates with esophageal atresia and tracheoesophageal fistula had a 93% survival, with four deaths in risk group C. Temporary postoperative morbidity related to the anastomosis occurred in ten patients. All patients had some disturbance in esophageal motility. While all have been studied for gastroesophageal reflux, only five had significant reflux, and four required fundoplication. Five patients with isolated esophageal atresia survived staged repair, and an additional five patients with H-type fistulae survived primary repair, including one with a long tracheoesophageal cleft. Despite the fact that 45% of the 63 patients had significant associated anomalies, initial survival was 93.5% and late survival 91%. Long-term functional results were generally satisfactory.

Esophageal Atresia↗

Early operation with intestinal diversion for necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) remains a highly lethal disorder despite significant advances in management during the past decade. Increased mortality with perforation and the frequent finding of massive intestinal necrosis have hampered efforts to improve survival. A recent experience with early operation and intestinal diversion in selected patients with clinical features suggesting impending intestinal gangrene suggests a place in the management of infants with rapidly progressive NEC.

Enterocolitis, Pseudomembranous↗

Management of major thromboembolic complications of umbilical artery catheters.

Over the last 9 yr approximately 4000 infants have had physiologic monitoring with UAC at Vanderbilt University Medical Center. A larger number of them had minor ischemic complications prompting removal of the catheter, but 41 patients had major thromboembolic problems requiring varying degrees of surgical management. The place of surgery is clear in patients with catheter emboli or bleeding due to vascular avulsion related to catheter removal. Patients with arterial occlusion distal to the femoral artery may be treated expectantly although significant skin loss may occur. Occlusions at the femoral level allow limb survival, but the long-term outlook is not known; perhaps these patients may better be subjected to femoral thrombectomy in the future. Peripheral pulses are not normal early and Doppler studies suggest that collateral circulation is responsible for limb survival. Whether this will be sufficient to support adequate limb growth and function remains to be seen. Patients with signs of aortoiliac or mesenteric occlusion should be rapidly investigated and operated upon if survival is to be obtained. This study suggests that an aggressive surgical approach is in order. Computer-assisted radionuclide flow studies are helpful in diagnosing major aortic occlusion, as well as for followup.

Catheterization↗

Neonatal necrotizing enterocolitis associated with penicillin-resistant, toxigenic Clostridium butyricum.

The cause of neonatal necrotizing enterocolitis (NEC) is unknown. An association between NEC and clostridial infection has been reported from several centers, but the organisms have not been extensively characterized. Clostridium butyricum was isolated from the peritoneal fluid and cerebrospinal fluid of a neonate with NEC. The organism was resistant to the penicillins, but sensitive to vancomycin. Toxin production was demonstrated. Although the role of clostridial toxins in the pathogenesis of NEC is unknown, clostridial toxins are well established as the causes of two other intestinal diseases (antibiotic-associated pseudomembranous colitis and pig-bel). Further investigation of the role of clostridia in the pathogenesis of NEC and of the use of oral, nonabsorbable antibiotics in the treatment of NEC is needed.

Bacterial Toxins↗