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Biomedical subjects

W W Neblett

Publications and source records attributed to W W Neblett.

At least 19 recordsLinked to original sources
PubMed1996

Bronchoscopic airway evaluation facilitated by the laryngeal mask airway in pediatric patients.

The laryngeal mask airway (LMA) was introduced for clinical use in 1988. It represents a new concept in airway management. Its role has been described as filling the gap between tracheal intubation and the anesthesia face mask. It is inserted without direct visualization into the hypopharynx and when properly positioned forms a low pressure seal around the laryngeal inlet, allowing spontaneous as well as gentle positive pressure ventilation. Since its introduction, its indications and applications in anesthesia practice have increased. Although initially used as a means of delivering anesthesia and obviating the need for holding a mask on the patient, its position directly over the laryngeal inlet makes it a useful guide during flexible bronchoscopy. We report our experience in six pediatric patients and describe an anesthetic technique for bronchoscopy using the LMA for general anesthesia with spontaneous ventilation.

Anesthesia, General↗
PubMed1995

Update on the analysis of the need for pediatric surgeons in the United States.

UNLABELLED: Accurate estimations of pediatric surgical manpower needs are necessary if this specialty is to avoid the consequences of under- or oversupply, and reasonable decisions must be made relative to the number of training programs needed. METHODS: Fifteen, 10, and 5 years ago, pediatric surgeons (PSs) in 62 standard metropolitan statistical areas (SMSAs) having a population of at least 200,000 were asked to estimate the number of PSs needed in their localities. A computer program analogous to the SOSSUS program was designed to project the number of PSs that would result from various numbers of trainee graduates per year. The program has been updated for comparison. Known input data included the present number and age of PSs, age range of trainees, current US population projections to the year 2025, and the average retirement age. RESULTS: These PSs estimated that 88 additional PSs are needed in the next 10 years. Currently, 26 programs in the United States graduate an average of 24 trainees per year, and six programs in Canada graduate six trainees per year. The previous projection indicated that 20 trainees per year would result in 525 PSs in 1993, and the actual number is 559; so the figures indicate that 27 or 28 PSs are entering practice each year. The apparent increase in numbers is related to entry of Canadian trainees primarily, and a few others, into practice. The current computer projection indicates that 20 graduate trainees per year would result in an absolute increase of 0.55% per year, and 25 per year would result in an increase of 1.43% per year, to 2020, while the increases in the US population would be 1.02% per year for all ages and 0.52% for 0 to 15 year olds. If all programs currently being considered for approval are certified, as many as 36 trainees per year--or 7 times the rate of the 0-15-year population increase--will result. CONCLUSION: Although an average of 20 graduates per year entering practice would keep pace with the pediatric population, 25 to 27 graduates per year--or 3.5 to 4 times the rate of the 0- to 15-year population increase--can be accommodated now into the current system of delivery of pediatric surgical care on the basis of estimated need. Many more graduates than this would create an excess of surgeons before long.

Canada↗
PubMed1995

The antral nipple sign of pyloric mucosal prolapse: endoscopic correlation of a new sonographic observation in patients with pyloric stenosis.

This study describes the antral nipple sign of pyloric mucosal prolapse, a newly delineated sonographic observation in patients with pyloric stenosis, correlates the endoscopic findings, and examines its prevalence and significance in 31 consecutive patients with pyloric stenosis. Fifty patients who did not have pyloric stenosis served as the control population. The antral nipple sign consists of visualization of prolapsed, hypertrophied pyloric mucosa protruding into the gastric antrum. Using the Wilcoxon scores (rank sums), there was no significant difference among the patients in age, weight, or pyloric muscle dimensions. Although the diagnosis of pyloric stenosis is made on the basis of muscle thickness, we have documented that the pyloric mucosa becomes redundant in infants with pyloric stenosis, permitting a fuller understanding of the anatomic correlate underlying the sonographic images.

Endoscopy, Gastrointestinal↗
PubMed1994

Laparoscopic cholecystectomy in infants and children: modifications and cost analysis.

Between June 1990 and February 1993, 26 children underwent laparoscopic cholecystectomy. Their ages ranged from 25 months to 19 years (mean, 12.3 years; median, 13 years). Only six of them had hemolytic diseases associated with gallstones. Five presented with acute cholecystitis. Laparoscopic cholecystectomy was performed on these five, within 5 days of admission; the mean postoperative hospital stay was 2.5 days. The other 21 patients underwent elective cholecystectomy; their mean postoperative stay was 1 day. Several modifications have been made in our technique. Three 5-mm ports and one 10-mm umbilical port are used. In addition, direct incision of the umbilical fascia is performed with insertion of a blunt trocar and cannula rather than using the Veress needle for insufflation. The importance of positioning the epigastric cannula in the left upper quadrant in small children cannot be overemphasized. Cholangiography is now attempted in all patients and is easier with the Kumar cholangioclamp and sclerotherapy needle, under fluoroscopy. The total hospital charges for the patients who underwent elective laparoscopic cholecystectomy are compared retrospectively with those of seven children who had elective open cholecystectomy during the same period. In addition, a comparison is made between the two groups with respect to the costs of operating room equipment and postoperative pain control.

Child↗
PubMed1994

Hypertrophic pyloric stenosis in the infant without a palpable olive: accuracy of sonographic diagnosis.

PURPOSE: To evaluate the accuracy of sonography for both diagnosis and exclusion of pyloric stenosis in the infant with nonbilious vomiting without a palpable olive and to clarify the relationship between infant age and size and the dimensions of the hypertrophic pylorus. MATERIALS AND METHODS: The sonograms of 152 infants with suspected pyloric stenosis were evaluated. The prospective diagnoses were categorized as pyloric stenosis, normal pylorus, and pylorospasm with potential to progress to pyloric stenosis. Positive findings were confirmed at surgery; negative findings were confirmed by means of chart review. RESULTS: Sensitivity, specificity, and accuracy of sonography in determination of appropriate surgical referral were 100%. A significant (P < .05) correlation was found between the size of the hypertrophied muscle and the age of the patient at initial examination. CONCLUSION: Sonography is highly sensitive and, in this patient population, highly specific, and by virtue of direct visualization of the pyloric muscle, it is the method of choice for both diagnosis and exclusion of pyloric stenosis.

Humans↗
PubMed1994

Laparoscopy for the nonpalpable testis.

Between 1988 and 1992, 287 infants and children have been evaluated for an undescended testis. In 35, the testis was not palpable. These 35 patients ranged in age between 10 months and 14 years, with a mean of 44 months and a median of 15 months. Thirteen patients had a nonpalpable right testis, 18 had a nonpalpable left testis, and four had bilateral nonpalpable testes. Diagnostic laparoscopy was performed in these 35 boys with a nonpalpable testis to allow a planned approach to management of this condition. In 11 children, a testis was visualized. The testis was in an inguinal hernia sac in seven, and single stage conventional orchiopexy was performed. In four children an intra-abdominal testis was seen, and three infants underwent laparoscopic clip ligation of the testicular vessels. One teenager underwent orchiectomy. In 21 of the remaining 24 boys, small, attenuated testicular vessels were noted to pass into the inguinal canal and inguinal exploration was required. A small testicular remnant was excised in 15 patients, but orchiopexy was possible in six boys. Diagnostic laparoscopy takes 7 to 10 minutes and enables the surgeon to develop a planned approach to this condition. With the information gathered at laparoscopy, the surgeon is best able to decide if an inguinal exploration is necessary or if a single-stage orchiopexy is possible. If a two-stage orchiopexy is required for an intra-abdominal testis, then clip ligation of the testicular vessels can be performed laparoscopically as the first stage, followed by Fowler-Stephens orchiopexy 6 to 9 months later.

Adolescent↗
PubMed1993

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1985

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↗