Cost-effective imaging approach to the nonbilious vomiting infant.

OBJECTIVE: To develop a cost- and time-effective algorithm for differentiating hypertrophic pyloric stenosis (HPS) from other medical causes of emesis in infants referred from community-based pediatricians and family practitioners to the imaging department of a tertiary children's care facility. METHODS: Eighty-nine vomiting infants (22 females, 67 males) between the ages of 11 and 120 days (mean, 43.5 days) had received nothing by mouth for at least 1 hour before the study. Each child was assessed for duration of vomiting, status of body weight, time and volume of last ingestion, and time of last emesis. A #8 French (Sherwood Medical, St Louis, MO) nasogastric feeding tube was placed in the child's stomach. The contents were aspirated and measured to determine likelihood of HPS. An aspirated volume >/=5 mL implicated gastric outlet obstruction, and ultrasonography (US) was performed. If this study was positive for HPS, the patient was referred for surgery. If US was negative, an upper gastrointestinal series (UGI) was performed. An aspirated stomach contents volume <5 mL suggested a medical cause for the emesis, and UGI was performed. Pediatric surgeons with no knowledge of the volume results palpated the abdomens of 73 of 89 infants (82%). RESULTS: Twenty-three of 89 patients (25%) had HPS. The aspirate criteria for HPS had a sensitivity of 91%, a specificity of 88%, and an accuracy of 89%. Of the false-positive studies (total = 8), six were related to recent significant ingestion (within 2 hours of the study), and two were attributable to antral dysmotility. The surgeons palpated the mass in 10 of 19 patients (53%). Sensitivity and specificity were 53% and 93%, respectively. Only 6 of 89 infants (7%) required both US and UGI to determine the etiology of the nonbilious vomiting. By performing the UGI in 66 patients, it was also found that 14% had slow gastric emptying and 79% had gastroesophageal reflux. Eighty-one percent of the gastroesophageal reflux was significant. CONCLUSION: The volumetric method of determining the proper imaging study is cost- and time-effective in the evaluation of the nonbilious vomiting infant for pyloric stenosis. If US was performed initially in all patients referred for imaging, two studies would have been performed in 68 of 89 patients (76%) to define the etiology of the emesis. Because we used the volumetric method, 62 fewer imaging studies were performed, representing a savings of $4464 and 30 hours of physician time. If children are given nothing by mouth for 3 to 4 hours before gastric aspiration, the specificity of the volumetric method improves to 94%, and the accuracy improves to 96%.

Evaluation of contrast media for bronchography.

BACKGROUND: Bronchography is occasionally needed for the evaluation and management of some congenital pulmonary anomalies as well as some acquired diseases, usually of the tracheo- bronchial tree. There is currently no effective, approved contrast agent for this imaging techniq ue. OBJECTIVE: We evaluated five agents (barium sulfate, iohexol, propyliodone oily, propyliodone aqueous, and perflubron) in terms of image quality, histologic changes, and effects on hemodynamics, blood gases, and standard laboratory tests in New Zealand White rabbits. MATERIALS AND METHODS: Animals were anesthetized and intubated. Each contrast agent (0.25 ml/kg) was administered intratracheally. Three animals in each group had intravenous lines placed for blood sampling and blood pressure monitoring and were sacrificed at 1 h. An additional three animals for each agent were sacrificed at 24 h and 1 week after imaging. Blood samples were taken immediately before contrast instillation and at 1 h postbronchography. Fluoroscopic images were recorded on standard VHS video tape and evaluated in blind fashion. Segments of lung tissue and bronchi were obtained for histologic examination. RESULTS: Necrosis and/or inflammatory infiltrates were noted in 78 % of the bronchograms performed with propyliodone aqueous, 67 % with propyliodone oily, 55 % with perflubron, and 33 % with iohexol 120, 240 and 350. No histologic damage was observed with barium. The propyliodones gave the best-quality imaging results and the most histologic changes. Iohexol, in any concentration, gave the least acceptable images and a moderate number of histologic changes. Barium sulfate demonstrated acceptable images with virtually no histologic changes. CONCLUSION: From the histologic and imaging results, barium is the best available contrast material for bronchography.

Surgical correction of hydrothorax from diaphragmatic eventration in children on peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) is frequently used in the pediatric age group for reversible and end-stage renal failure. Most pediatric patients tolerate this therapy with few complications. Approximately 2% of children, however, develop massive unilateral hydrothorax. This major complication usually results in the discontinuation of peritoneal dialysis in all forms and the institution of hemodialysis. Occult diaphragmatic defects account for most adult and pediatric patients who develop this complication. Three pediatric patients receiving CAPD complicated by massive hydrothorax are described. All patients were successfully treated by thoracotomy and repair of the diaphragmatic eventration with an immediate return to CAPD. This is the first report of successful therapy of this kind in children. A review of the cause, diagnosis, and treatment of massive hydrothorax developing during CAPD therapy is presented.

Triglyceride absorption in transperitoneal alimentation.

In 17 fasted rabbits, a 20% solution of Intralipid was administered into the peritoneal cavity. Oral and intravenous feedings were not provided. Eight of the rabbits underwent resection of 50% of the intestine. Serial samples of serum and peritoneal fluid showed that half of the triglyceride was absorbed within 1 hour in rabbits with intact viscera, but not until 2 hours in rabbits with intestinal resection. The caval-arterial gradient for triglycerides was consistently positive in rabbits with intact intestine, whereas it was smaller and erratic after intestinal resection. The portal-arterial gradient was never significantly different from zero. These data indicate that the major triglyceride absorption occurred across the visceral peritoneum through lymphatic vessels, with little portal venous absorption. Transperitoneal absorption of triglycerides occurred to a sufficient degree to provide substantial nutritional supplementation in rabbits with intact intestine; absorption was less in rabbits with intestinal resection.

Morphologic effects of orchiopexy or orchiectomy on the contralateral testis in experimental unilateral cryptorchidism.

For evaluation of the effects of orchiopexy and orchiectomy on the contralateral descended testis, unilateral cryptorchidism was produced in 60 21-day-old mice by suturing of the left testis to the inner abdominal wall. A sham operation was performed on the left testis of 20 control mice (S). After creation of unilateral cryptorchidism, orchiopexy (P) or orchiectomy (O) was performed on the left testis at 2 (group I) and 10 (group II) weeks (ten mice each). All testes were removed for examination 2 weeks after orchiopexy or orchiectomy. In both groups the mean values of testicular weight, seminiferous tubular diameter, and tubular biopsy score of contralateral O testes were always statistically similar to the values of contralateral S testes (p greater than 0.01). The difference between TBS values of contralateral P and S testes was not significant in group I (p greater than 0.01), but it was significant in group II (p less than 0.01). The data from this murine experiment suggest that orchiectomy for unilateral cryptorchid testis is almost always helpful in improving contralateral morphology; however, orchiopexy can be helpful if it is not performed late in the period of maturation.

Morphologic effects of unilateral cryptorchidism on the contralateral descended testis.

Unilateral cryptorchidism is frequently accompanied by infertility. Uncertainty exists as to whether the infertility is a genetic effect or is related to an autoimmune reaction to the elevated testis. The effects of unilateral cryptorchidism were evaluated in 50 mice by surgically elevating the left testicle of 21-day-old mice into the abdomen (AT). A sham operation was performed on the left testicle of 50 control mice (SHT). The temperature of the abdominal testes measured 2.5 degrees C higher than the scrotal testes. The testes were removed from both sides at 1, 2, 3, 4 and 6 weeks postoperation. After testicular weights were recorded, seminiferous tubule diameters were measured, and germinal epithelium maturity was graded histologically using a modified Johnson testicular biopsy score. Progressive abnormal changes were seen in the contralateral descended testicles of AT as compared to SHT. By 3 weeks, though testicular weight changes were similar, mean seminiferous tubule diameter was smaller (P less than .001), and the germinal epithelium was less mature (P less than .001). These changes persisted through the sixth week. By changing the physiologic environment of one testicle, we have induced alterations in the histologic appearance of the contralateral testicle during the period of normal maturation.